The magnetic bearing system are intrinsically unstable, and need the feedback control of electromagnetic forces with measured displacements. So the controller design plays an important role in constructing high performance magnetic bearing system. In case of magnetic bearing system, the order of identified model is high because of unknown dynamics included in closed loop systems - such as sensor dynamics, actuator dynamics - and non-linearity of magnetic bearings itself. In this paper the identification and robust control of flexible rotor supported by magnetic bearing are discussed. We measure and identify overall system that contains not only flexible rotor model but also magnetic bearing and time delay. The structured and unstructured uncertainties are modeled that cover variations of natural frequencies, uncertainties in sensor and actuator gains and unmodeled dynamics. And desired performances are specified with several weighting function. Using augmented system that includes identified model, uncertainties, and weighting functions, μ-synthesis is applied to flexible rotor supported with magnetic bearing. The flexible rotor was spin up over the first flexible critical speed.

Inadequate footholds selection may result in deadlock state where the walking vehicle can not anymore to the desired direction. This paper concerns about the footholds selection for quadruped v, vehicle to walk with the leg lifting sequence of crawl gait which is desired for straight motion. supporting states for lifting a leg are defined and the proper supporting condition for quadruped c: also proposed. When selecting a footholds of swing leg within the proposed footholds searching are; supporting states after the swing legs are placed, satisfy the proper supporting condition. So it can I for quadruped to execute continuous walking with the lifting sequence of crawl gait.

This paper presents the vibration control of a glass-fiber reinforced thermoplastic composite beam with a distributed PVDF sensor and piezo-ceramic achlator. The three types of different controllen which are PID, H$\infty$ , and p-synthesis ontrollcr are employed to achieve vibration suppression in the transient vibration of composite beam. In the H$\infty$ , controller design, 1st and 2nd natural frequencies are considered in the modeling, because robust control theory which has robustness to struchred uncertainty is adopled Lo suppress the vibration. If the controller designed by H$\infty$ , theory does not satisfy control performance, it is improved by $\mu$ -synthesis method with D-K iteration so that the$\mu$-contoller based on the structured singular value satisfies the nominal performance and robust performance Simulations and experiments were carried out with the designed controllers m order to demonstrate the suppression efficiency of each controller.

We developed a human-sized BWR(biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. The robot overcomes the limit of the driving torque of conventional BWRs. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. The BWR was developed to walk autonomously such that it is actuated by small torque motors and is boarded with DC battery and controllers. In the performance test, the BWR performed nice motions of sitting-up and sitting-down. Through the test, we could find capability of high performance in biped-walking.

Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and its's high sensitivity. Especially, when projecting a grid pattern over the object the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, new method for grid pattern generation system by polygonal mirror and Laser Diode. This system is applied the projection moire and the PMP.

This paper descrtbcs our prlmary study for a new mncthod of recogninng materials. which is need for precision work system. This IS a study of dynarnlc characteristics of sensor. new melhod ($R_{SAI}$) has thc sensing ability of distinguishing materials. Experiment and annlysis are executed for proper dynamic scnslng condition. First. we developed advanced smart sensor Second, we develop new methods that have a sensing ability of distinguish matarialsAccording to frequency changing. mtluence of smart sensor are evaluated through new recognition Index ($R_{SAI}$) that ratioof sensing ability index. Disungush of object is cxucuted wllh RsA, method relalivcly according to liequency changing. Wecan use the RsAl for finding materids. Applfciltionr of thls method are linding abnormal condition of obicct (automanufacturing).keling ofobject (medlcal product). tobolics, safety diagnosis of structure, etc

In this paper, we determine the design criteria of haptic device considering the human haptic system and determine the design specifications. We developed a new 2DOF haptic device based on the specifications. It has the wide workspace, statically-balanced, constant inertia matrix, well-conditioned Jacobian matrix and so on. There also is not singularity point within workspace of the device. We show that it has better performance than other 2DOF haptic device in the many aspects.

A cantilever deflection measurement system for AFM(atomic force microscope) was constructed by the laser deflection method using LEP type PSD. Design process including sensitivity analysis was presented and the performance of the system was demonstrated by several experiments using a sample specimen with 50nm-step on the surface. The measured displacement-amplification-factor showed good agreement with the expected one with about 8% deviation. The step height measurement data were compared to what were acquired by commercial AFM, and the result showed that there were about 5nm-deviation between the two data. These results satisfies our expectation in the stage of system design.

Cutrent technological development toward miniaturization requires smaller components. These components usually generate complex multi-DOF motions other than simple 1-DOF motlon. Therefore it is essential to develop measurement methodology for 6-DOF motions. In this paper, a new 6-DOF measurement system for milli-struchlre is presented. This methodology basically employs the Optical Beam Deflection Method (OBDM) with a diffraction grating. A laser beam is emitted toward the difliaction grating which could be attached on the surface of a milli-structue and the incident ray is dif'||'&'||'acted in several directions. Among these difliacted beams, $0^{th}$ and $\pm$ $1^{th}4" order difkicted rays are detected by 4 Quadrant Photodiodes. From coordinate values fram each detector, we can get information for 6-DOF motions with lineariration method, Required resolutions for milli-struchue measurement are suh-micrometer in translation and arcsec in rotation. Experimental results indicate that proposed system has possibility to satisfy this requirement.

Optical triangulation displacement sensors(0TDSs) are widely used for their simple struchlre, high resolution, and long operating range. However, there are several factors that must be taken into account in order to obtain high accuracy and reliability Measurement errors from inclinations a？ an object surface, prohe signal fluctuations generated by speckle effects. power vanation of a light source, electronic noises, and so on. Previous models of OTDSs can not show reasonable behavior as change of surface inclination and shape of light intensity distribution on the detector. In this paper, we propose a new and reasonable modeling for diffise-type OTDSs based on a geometrical optics. To verify propriety of new modeling, we take basic experiments. Shape of light intensity distribution is asymmetric in both simulation result and experimental result. Both simulation result and experimental result show same tendency of light intensity distribution movement as changing surface inclination

Optical triangulation is one of the most common methods for acquiring range data. Using this method. We have developed a new type of Laser Displacement Sensor. We used Area CCD instead of linear CCD and PSD (Position Sensitive Detector). And we have developed the robust algorithm for increasing the accuracy and used USB instead of RS-232C for increasing speed. We present results that demonstrate the validity of our method using optical triangulation technique, Area CCD, and USB.

The traditional surface measuring method using confocal principle requires much time to measure an object surface since it is a scanning tool. In this paper, the upgraded confocal microscope is introduced. It is also a scanning tool but it requires 2D-scanning while the traditional one requires 3D-scanning. It means the time for measuring is considerably reduced. In addition, the measuring system is configured to increase the efficiency of beam. He-Ne laser whose frequency is 632.8nm is used for the laser source. An example of measuring result through the upgraded confocal microscope is showed.

Nonlinearity is one of the primary causes of error in precision length measurement using laser interferometer. It arises periodically. The periodical nonlinearity usually ranges from sub-naometre to several namertres. In the homodyne interferometer, it results from a number of factors including polarization mixing, imperfect optical clement, unequal gain of detectors, misalignment of axes between input beam and beam splitter. In this paper, we described a method for measuring and compensating the nonlinearity of homodyne interferometer using the elliptical least-square fitting technique associated with electric method and experimental results in one frequency polarization interferometer.

In this study, efficient force reflection algorithm is developed for the Haptic Display by using a proxy concept and friction model. When there are not any contacted obstacles the proxy is following human operator's command trajectory in the 3D virtual space. But when the operator's command trajectory is locating inside of the object, the proxy is constrained by the surface of the object. Here only with the information of the proxy position and operator's command trajectory at every time step, we can calculate the reflection force and its orientation. To display the friction force between two virtual stiff material which are sliding against each other, modified Karnopp's friction model is used. In the friction model, a damping term and a Stribeck effect term are included to display the relative velocity effect and stick-slip effect at the very low relative velocity region respectively.

It is usual that the medical examination of human body need special knowledpe and equipments. Thus we have to spend Lime and energy on going to special place such as hospital where doctors and equipments are. Which often cause missing a good chance af medical treatment as well as giving us inconvenience. However many simple and convenient equipments were developed for checking our health conditions recently. O-ring test is accepted a3 one of useful methods to examine our heallb conditions. Also the test is recognized as a uscful means to judge, withoul any special equipment and medical knowledge, if some medical substances or foods are beneficial or harmful to our health. However, the judgement may be mcorrect because it depend on doctor's subjective point of view.In this study, we developed an automatic O-ring t a r mach~ne which enable us to check our health conditions objectively and quantitatively. The validity of the idea to develope the machine was proved by experiments.

A tool holder system has been designed to measure cutting forces in diamond turning. This system includes a 3-component piezo-electric tranducer. In this research, tool holder system is modeled by considering the element dividing, material properties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of structure is simulated by MSC/NASTRAN, for the purpose of developing the effective design. In addition, tool holder system is verified by vibration test using accelerometer. This system will aid to the development of Fast Tool Servo.

This paper presents a simulation study on the description of the motion and the control of an active catheter actuator with multi-link structure actuated by Shape Memory Alloy(SMA). The model of an active catheter adopted in this paper has 3 links, and the individual links are composed of 3 micro coils of SMA for the omni-directional motion. In order to analyze the motions of multi-link structure, 3-dimensional kinematics description is presented. Also, the motion control of the end point of an active catheter using simple Neural Network is shown based on GUI(Graphic User Interface) system.

This paper describes a coordinate measuring technique based on optical triangulation using the two images. To overcome the defect of structured light system which measures coordinate point by point, light source is replaced by CCD camera. Pixels in CCD camera were considered as virtual light source. The overall geometry including two camera images is modeled. Using this geometry, the formula for calculating 3D coordinate of specified point is derived. In a word, the ray from a virtual light source was reflected on measuring point and the corresponding image point was made on the other image. Through the simulation result, validation of formula is verified. This method enables to acquire multiple points detection by photographing.

Rotating machine is used extensively and plays important roles in the industrial field. Therefore when rotating machine get out of order, it is necessary to know reasons then deal with the troubles immediately. So many studies far diagnosis of rotating machine are being done. However by this time most of study has an interest in gaining a high recognition But without considering error $rate^{(1)(2)(3)}$ , it is not desirable enough to apply h the actual application system. If the manager of system receives the result misjudging the condition of rotating machine and takes measures, we would lose heavily. So in order to play the creditable diagnosis, we must consider error rate. T h ~ t is. it must be able to reject the result of misjudgment. This study uses nearest neighbor classifier for diagnosis of rotating $machine^{(4)(8)}$ And the Smith's rejection $method^{(1)}$ used to recognize handwritten charter is done. Consequently creditable diagnosis of rotating machine is proposed.

In this paper, the ultra precision positioning system for piezoelectric actuator using hysteresis compensation has been developed. Piezoelectric actuators exhibit limited accuracy in tracking control due to their hysteresis nonlinearity. The main purpose of the proposed controller is to compensate the hysteresis nonlinearity of the piezoelectric actuator. The controller is composed of a PD, hysteresis compensation and neural network part in parallel manner, at first, the excellent tracking performance of the neural network controller was verified by experiments and was compared with the classical PD controller.

Laser claddmg 1s thc deposition of material on the surface of a part or workpiece. Cladding of metals produces a 100% dense metallurgically-bonded coating with minimal dilution for enhanced corrosion, abrasion and wear resistance. Despite of minimal heat Input and reduced processing time, cladding quality 1s affected by various process condition such as laser power and feed rate. Therefore, it is necessary to develop the momtoring and control methods of laser cladding process for the best cladding quality. In this paper, laser cladding monitoring system using CCD camera for measuring cladding pool shape, and photo-diode sensor for detecting optical signal emitted from the cladding front is introduced The variables extracted using this system can be apphed to control the laser cladding system to achieve the best claddmg results..

This study discusses a non-contact optical technique, phase shifting electronic speckle pattern interferometry, that is well suited for a deformation measurement. However, the phase shifting method has difficulties for determinating a deformation quantitatively beacuse of the characteristics of arctan function. In order to solve this problem, phase unwrapping methods has been studied during the last few years. In this study, using phase unwrapping based on line by line scanning phase shifted fringe patterns are studied to determinate a deformation quantitatively. Also least square fitting method is applied to reduce noise and improve image resolution.

The AE measurement is one of the most convenient methods for detecting contacts between slider disk. The AE method has been widely used in the investigation of the tribology of sliding interfaces due to the convenience of using AE sensor. In this study, we examined the relationship between the AE signal and the flying height of a slider. We tried to know the influence of the disk velocity on the AE rms signal by using the AE measurement system. The experiment also gives the relationship between the take-off velocity and the disk surface state. To investigate the behavior of the slider further, the variances of the AE signal are analyzed. The results about a subambient pressure slider indicate that the increase in the magnitude of AE rms signal does not necessarily mean the slider/disk contacts.

A simple digital control system has been developed for the frequency stabilization of an internal mirror He-Ne laser. The system is based on one chip microprocessor with embedded Basic interpreter. To stabilize the laser output frequency, the signal such as power difference or beat frequency between two modes is supplied and processed by a microprocessor, and control signal is fed to the heating coil would round the laser tube for adjusting the spacing of the laser cavity mirror. Newly developed frequency stabilization system is totally digitized. The system and the frequency stability performance are briefly described.

The virtual reality - haptic device is developed for the purpose used in the work that human cannot approach and that need elaborate exercises. To render haptic, the total system is constituted master, haptic device, and slave, remote manipulator. Human operates the remote manipulator. Human operates the remote manipulator relying on the hapti devices and stereo graphic. And then the force and scene of the remote manipulator is fed-back from each haptic devices and virtual devices. The feedback information gets system gain exactly. The system gain provides the most exact haptic and virtual devices. The feedback information gets system gain exactly. The system gain provides the most exact haptic and scene to human by the location, the graphic rendering and the haptic rendering algorithm on real-time. In this research, 3D haptic device is developed for common usage and make human feel the haptic when human contacts virtual object rendered by computer graphic. The haptic device is good for tracing location and producing devices because of the row structure. Also, openGL and Visual Basic is utilized to the algorithms for haptic rendering. The haptic device of this research makes the interface possible not only with virtual reality but also with the real remote manipulator.

In general, speed control method of the elevator system has used motor pole change type or motor primary voltage control type. But it will change to vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control that primary current of the induction motor be controlled independently with magnetizing current(field current of DC motor) and torque current(armature current of DC motor). In this paper, by analyzing the effect of the time constant variation of rotor of the induction motor on the slip frequency type indirect vector control, a drive system for the motor will be constructed using a fuzzy slip frequency type indirect vector controller with fuzzy control method for estimating the vector time constant in the slip frequency type indirect vector control. The goal of this study is to enabling even more efficient speed control by constructing on elevator driver based on the newly developed drive system.

We developed a motion capture system to get angle data of human joints in walking mode. The data are used to coordinate the biped-walking robot developed in our laboratory. A pair of motion capture system is composed of three links with the ankle, knee, and pelvis joints. The system has six axes attached with potentiometers. We used an A/D converter was used to get digital data from joint angles. We filterd the data using the Butterworth 4th order digital filter, and simulated walking motion based on the data using the Matlab.

Recently, High accuracy and precision are required in various industrial field especially, semiconductor manufacturing apparatus, Ultra precision positioning apparatus, Information field and so on. Positioning technology is a very important one among them. For composition of this technology, the development of system with high speed and high resolution is needed. At start point and end position vibration must be repressed on this system for composition of position control. This vibration is arisen nose, is increased setting time, is reduced accuracy. Especially, repressed for the lead with high speed. The small actuator with high speed and high resolution is need to repression against this residual vibration. This actuator is, for example, piezo actuator, piezoelectric material that converting from electronic signal to mechanical force is adequate material, beacause of control of control to position and force. In this study, piezo electric material is used to actuator, ultra precision positioning apparatus with stage of hinge structure is designed, simulation is performed, control performance is tested by producing apparatus. For easy usage and stability in industrial field, we perform to simulation and to position control test by digital PID controller.

An elevator system which is a essential equipment for a vertical movement of object, as a property of building, have been drove by various expenditure and purpose. Since developing electrical control technology, control systems are highly developed. An elevator equipment is expended to wide, but a data accuracy acquisition technique and safety predict technique for securing system safety is still basic level. So, objective verification for elevator confidence condition is required absolutely accuracy measurement technique. Therefore, this study is accomplished in order to conquer a method of depending on sense of a manager with a simple numeric measurement data, and construct a logical, analytical foresight system for more efficient elevator management system.

The paper presents both theoretical and experimental study for dynamic instabilities of a vertical cantilevered pipe with two attached lumped masses conveying fluid. The two attached lumped masses can be considered as valves or some mechanical parts in real pipe system. Eigenvalue behaviors depending on the flow velocity are investigated for the change of positions and magnitudes of an attached lumped mass and a tip mass. In order to verify appropriaty of numerical solutions, experiments were accomplished. Theoretical predictions have a good agreement with experimental ones.

The development of a robot system being able to work instead of human in the hazardous environment have been conducted for many year. In this study, the new design of controllers for the Master-Slave system is discussed. The Master-Slave system, force, velocity and torque signals are communicated between a master and a slave system. the conventional requires the enhancement of characteristics of tactility for minute force, precision signals and mechanical abrasion of loader. It is possible b controlling the viscosity of ERF(Electro-rheological fluid) since it varies with the electric field. Design of controller as well comparison between numerical simulation and experiments as will be presented. Futhermore, current methodology is also applicable to design of tele-surgery

Controller refinement scheme to improve the performance of a conventional system automatically in frequency domain is proposed. The controller automatic tuning method features using experimental frequency responses of the conventional closed-loop system, the conventional controller, and the improved closed-Imp system; instead of poorly modeled plant due to non-linearities and disturbances. The improved closed-loop system characteristics is automatically acquired by the conventional closed-loop system characteristics and the proposed performance index in system bandwidth. And the proper controller is realized by least squares approximation in frequency domain. To testify the usefulness of the approach, experimental results of robot path-tracking control applied with various controllers is used, and then is analyzed with respect to a equivalent proportional controller. Experimental results and analytic results are well-matched.

This research presents new type of remote monitoring and control solution of PLC that can be used bi-directional and efficient management of factory automation through internet. This system has client/server architect for information handling between PLC and remote computer where a user can control and monitor target PLC. Actually the authors redirect RS232C connection between PLC and server computer into Internet connection between PLC and remote client computer using supplied PLC tool program So user feel like in front of PLC panel when he operates remote PLC through Internet. Each client/server program is constructed with Java language for security. In this paper the internet-based remote control system was proposed and proved validity by being applied to redirection of PLC control for factory automation.

In this paper, ANFIS intelligence control of a semi-active suspension system is investigated. The strength of the ER damper is controlled by a high voltage power supply. This paper deals with a two-degree-of-freedom suspension using the damper with ERF for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using passive and ANFlS control method. Computer simulation results show that the semi-active suspension with ERF damper has good performances of ride quality

Detection of tool wear is very important in automated manufacturing. This paper presents tool condition monitoring system based on the wavelet analysis of the AC servo motro current in drilling and milling process. The current measurement system is relatively simple and its mounting will not affect machining operations. The discrete wavelet transform was used to decompose the current signal of a spindle AC servo motor in time - frequency domain. The feature vectors were extracted from the decomposed signals and compared for normal and wear condition. The results show the possibility for the effective application of wavelet analysis to tool condition monitoring.

This paper presents an PID type fuzzy based method for nohnear engine idle controller The output is a duty cycle(DC) for driving a idle speed cont개l valve(1SCV). For precise control of SI engine, the CPS sensor and coolant temperature are used. Visual C* language is used to make simulation panel for the fast and precise idle speed control. The dSPACE board and supported Control desk program is used in experiment ta the same purpose as simulation. The experimental results have a good agreement with simulation ones.

In this paper, the development of a new group controller for high-speed elevator is carried out utilizing approach of an adaptive dual fuzzy logic. A goals of control are the minimization of waiting time, mean-waiting time and long-waiting time in a high building, when a new hall call is generated, adaptive dual fuzzy controller evaluate traffic pattern and change appropriately the membership function of fuzzy rule, base. Control for co-operation among elevators in group control algorithm are essential , and the most critical control function in group controller is a effective and proper hall call assignment of elevators. The group elevator system utilizing adaptive dual fuzzy control reveals a great deal of improvement on its performance.

An improved robust hybrid control law is proposed This law uses the separated bounding function: so uncertainties of each axis does not affect the others. Also, this law uses the separated $\varepsilon$, so we can take different $\varepsilon$ for each axis This law guarantees the practical stability in sense of Lyapunov. Simulation was performed to validate this law using a four-axis SCARA type robot manipulator.

Engine noise is one of the major causes of the interior noise, and so has been studied in various ways in recent days. Recently air induction noise has been extensively studied to reduce the engine noise. Conventional method to reduce the noise is adding several resonators to the induction system. However this causes a reduction of engine output power and an increase of fuel consumption. Thus in this study, the feasibility of applying the active noise control to the induction system is studied to the overcome the above disadvantage.

In this paper, an OMM (On-the-Machine Measuring) system has been developed, which can perform measuring and inspection of sculptured surfaces of die and mold, by use of a scanning-type touch probe mounted into the spindle of a NC machine. The calibration procedures of a scanning prove (SP2-1, Renishaw) and an algorithm for measuring surface points by a ball-nosed stylus have been studied. The system has been developed based on commercial CAM software (Z-Master 2000), and tested through measuring a plastic injection molding-die. Also some experimental results of the calibration and measuring for given surface positions are analyzed to verify its accuracy and reliability.

An aerostatic stage has frictionless behavior, so it has a advantage of investigation into positioning characteristics. A one-dimensional aemstatic ceramic stage with ballscrew driven and laser scale feedback system is manufactured. aiming at investigating positioning characteristic of aerostatic stage, especially position error and repeatability, we analyze positioning behavior with other factors such as angular error, temperature. Experimemal results show that the aerostatic stage has a l0nm micro step response. Comparing experimental results and calculated abbe's error, we confirm that mean of position error is owing to angular error. And, also we confirm the temperature is dominant factor of repeatability in ten nm order.

This paper is concerned with achieving the high motion accuracy of linear motion bearing guide according to estimate accuracy average effect of bearing. Accuracy average effect can be obtained b analysis the relationship between motion error of the table and spatial frequency of the rail form error. And influences of ball diameter, ball number, and clock length on block motion error and block number on the table motion error are analyzed theoretically. In addition to, a simple experiment is performed in order to verify theoretical result.

This paper describes action of synchronous error between z axis and spindle axis on rigid tapping. Because rigid tapping cuts the threads synchronizing the movement of z axis to spindle rotation, synchronous error between z axis and spindle is very important. Increase of synchronous error degrades the accuracy of thread and crushes the tap in worst case. So we developed the realtime measurement system of synchronous error in order to know the action of synchronous error on rigid tapping. In result, we have known that synchronous error was increased according to rise of spindle speed and z axis speed. And because the cutting torque(M3-30Ncm∼M10-300Ncm) on rigid tapping are less than maximum motor torque(3500Ncm), it specially doesn't affect the synchronous error. The most important parameter which has affected the increase of synchronous error was acceleration/deceleration time. On worst case, spindle motor was tripped because of the excess of synchronous error. Because the acceleration/deceleration time ocuupies the most of the total cutting time, in order to move on the high speed rigid tapping, the acceleration/deceleration time of spindle must be remarkably reduced.

An analysjs model for calculation the motion accuarcy of double sides hydrostatic table is proposed in thn paper. For the analysis of motion accuracy, profiles of each rails are assumed as periodic function, and represented using Fourier coefficients. Variahon of bearing clearance is represented as the vanation of linear, angular displacement of table and profiles of rails. Motion accuracy is calculated in the basis of finite element analysis on the pressure dutributmn of table. In order to improve calculating time in the analysis of motion accuracy, The proposed modeling method converts double sides table to single side table equivalently Results by the proposed method 1s compared with directly caculated results mdyhcally, and also compared wlth experimental results. From the theoretical and experimental analysis, it is confirmed that the proposed modeling mothod is very effective to analyze the motion accuracy of dauble sides hydrostatic table.

It can be acquired the high effective productivity through of high speed, precision of machine tools, and then, machine tools will be got a competitive power. Industrially advanced countries already developed that the high speed feed is 60m/min using the high speed ball screw. Also, a lot of problems have happened the feed drive system. It is necessary to study about the characteristics of thermal deformation played a more critical role than static stiffness and dynamic rigidity in controlling the level of machining accuracy. In spite of the improving the thermal deformation characteristics of machine tools at the design stage, there are always some residual errors that have to be compensated for during machining. In this study, thermal deformation error automated compensation device with multiple linear regression is proposed that thermal deformation error can be eliminated at the machining stage. The developed device has been practically applied to the feed drive unit.

In this paper, we developed an expert system that helped a machine-tool designer to select a moderate servomotor of the feed drive unit of a machine tool. With the specification of the drive unit, it searches for the set of servo-motors that have enough torque and power to satisfy the driving condition which the designer defines from the database. me database also contains knowledge and rules, which describe the design process and calculate design parameters of a feed drive. The knowledge-based design support module shows every steps of inference and reason for the solution that it provides.

In the multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance the accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, the 3-axis slide system with tilting turret unit is researched with two approaches; The first is that 3-axis slide system is modeled and simulated usig ADAMS software. The dynamic behavior of this system is visualized by data graphs and dynamic animations. The first step of virtual prototype which makes it possible to design economically and effectively is developed.

Singular points are those at which the determinant of a Jacobian matrix is zero. A parallel manipulator gains mostly an extra DOF at the singular points, where it can not be properly controlled. In this study, singular points of a cubic parallel manipulator are illustrated by obtaining the determinant of a Jacobian matrix mathematically, and the singular points of the manipulator are found to be three separate planes in a 3D space. The dependency among links for each singular point is determined by applying linear algebra. Also, the singular points and workspace of the cubic parallel manipulator are plotted to check if the workspace contain singular points.

An error analysis is very important for a precision machine tool to estimate its performance. This study proposes a new parallel device, a cubic parallel manipulator. Errors of the proposed cubic parallel manipulator include universal joint errors, errors occurring due to changes in the fore directions in the links, and actuation errors. An error analysis is performed for the manipulator platform moving at uniform velocity. The analysis shows how the position and orientation of the platform influences the directional link forces that change the errors in the manipulator. The analysis shows that the method can be used in predicting the accuracy of parallel devices.

In multi-purpose lathe, the design of tilting turret slide system has on important and critical role enhance accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, 3-axis sliding system with tilting turret is modeled by considering the element dividing, material proprties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of each structures such as saddle, careg, and turret are simulated by MSC/MASTRAN, for the purpose of developing the effective design.

In this study for the development of a 3D pattern mill, we designed its layout which has high stiffness and low-weight structure. We calculated the load of each axis component when 3D pattern mill is under the worst cutting conditions. On base of the calculations, we determined the size of its structure and selected main components of the machine. Also, using FEM we analyzed the layout design of 3D pattern mill to reduce the wcight of structure and increase stiffness of it. According to the load position and direction, shapes and values of the deformation and the stress distributions are calculated, also we calculated the natural frequencies and mode shapes in order ta modify and redesign the weak parts

In this paper, the kinematics of the new type of parallel manipulator is studied, and neural network is applied to solve the forward kinematics problem. The parallel manipulator, called a Stewart platform, has an easy and unique solution about the inverse kinematics, however the forward kinematics is difficult to get the solution because of the lack of an efficient algorithm due to its highly nonlinearity. This paper proposes the neural network scheme as an alternative Newton-Raphson method. The neural network is found to improve its accuracy by adjusting the offset of the result obtained.

This research aims at developing a low-cost PC-NC system based on one-CPU and investigating the feasibility of its application to a simple-function lathe. Its hardware consists a two axes motion control board including a 24bit counter, 8253 timer, a 12bit DA converter, DIO board for PLC operation and a PC with Intel Pentium 466MHz. The fundamental real-time MC functions such as G-code interpretation, interpolation, position and velocity control of axes are performed. User programming interface with functions of icon manipulation, tool-path simulation and NC-code generation was implemented. In order to achieve real-time control and safety, axis control, NC interpretation, interpolation and user communication are completely executed during every interrupt interval of I msec.

CNC machine tool is assembled by central processor, PLC(Programmable Logic Controller), and actuator. The sequential control of machine generally controlled by a PLC. The main fault occured at PLC in 3 control parts. In LC faults, operational fault is charged over 70%. This paper describes diagnosis model and data processing for remote monitoring and diagnosis system in machine tools with open architecture controller. Two diagnostic models based on the ladder diagram. Logical Diagnosis Model(LDM), Sequential Diagnosis Model(SDM), are proposed. Data processing structure is proposed ST(Structured Text) based on IEC1131-3. The faults from CNC are received message form open architecture controller and faults from PLC are gathered by sequential data.. To do this, CNC and PLC's logical and sequential data is constructed database.

The purpose of this paper is to establish an effective inspection system by using OMM(ON-Machine Measurement) system. This allows us to reduce the manufacturing lead time by separating the inspection process from manufacturing system. As a first step, the inspection process planning is accomplished by determining the number of measuring points, their locations, measuring path and their sequence. Subsequently, we generate measuring G-codes to be transferred to the machining center through RS232C, and then the inspection process will be performed for each shape. Analysing obtained measuring data, the dimensional tolerance will be validated.

Productivty of tapping has been increasing through the tcchnological advances in synchronization between spindle rotation and feed motion even in the high spindle speed. However, not much researches have been conducted about tapping process because its complicate cutting mechanism. In order ta investigate the characteristics of the tapping process, this paper concentrates on the analysis of curting torque behavior during one cycle of lapping. As one completc thread is performed through the whole chamfer ercuttlng, cutting torque increases highly in chamfer cutting, but smaothly in full thread cutting Functioning of the threads guide. Cutting torque in backward cutting is smaller than in Sorwerd cutting due to only friction farce in against between the tool and workpiece. And torque behavior of a periodic Sine ripple-mark was identified during one revolution of a tap.

This paper presents the dynamic analysis and experiment for a shaft system supported by angular contact ball bearings. Among others, the dynamic characteristics of bearings are significantly affected by axial preload and radial load applied. This paper rigorously analyzes the dynamic characteristics of a shaft system with angular contact ball bearings subject of axial preload so as to result in eigenvalues as well as bearing stiffness characteristics. Experiments are also performed to identify natural frequencies and stiffness characteristics of bearings implemented. Comparison is made on the theoretical and experimental results.

In this paper, we developed an automated program for the modeling and manufacturing of three-dimensional roller gear cams. A computer program employing the theory of gearing and coordinate transformation is developed for synthesizing and animating cam mechanisms. A method using wire frame modeling and shading by triangular element is presented, and effectively used for modeling of example with reduced computation time. Then a module for generation NC program for a five-axis CMC machine to manufacture roller gear cam is established.

This study is to choose the most proper model for AGV throughout simulation of behavior of suspension to reduce trial and error because there is no AGV treating heavy weight at harbor loading and unloading at home. Therefore, we estimate the vibration modes of the various suspensions applied to AGV, which is over 75 ton included the weight of two containers using the Matlab, one of the simulation programs.

This paper presents a method to identify the on-set of chatter by using the chatter frequency-spindle speed diagram for a milling spindle-workpiece system in face milling process. To this purpose, the eigenvalue problem approach using frequency response function is adopted for predicting both the chatter condition and chatter frequency. The chatter frequency -spindle speed diagram for various conditions is investigated throughout simulation and experiment to diagnose the chatter. The simulation and experimental results show that the chatter frequency-spindle speed diagram is useful for diagnosis of the on-set of chatter vibration.

A part definition must not only provide shape information of a nominal part but also contain non-shape information such as tolerances, surface roughness and material attributes. Although machining features are useful for suitable shape information for process reasoning in the CAPP, they need to be integrated with tolerance information for effective process planning. We develop the tolerance modeler that efficiently integrates machining features with tolerance information for feature-based CAPP It is based on the association of machining features, tolerance features. and tolerances Tolerance features, where tolerances are assigned, are classified into two types; one is the face that is a topological entity on a solid model and the other is the functional geometry that is not referenced to topological entities. The functional geometry is represented by using machining features All the data for representing tolerance information with machining features are stored completely and unambiguously in the independent tolerance structure. The developed tolerance modeler is implemented as a module of a comprehensive feature-based CAPP system.

Reverse engineering refers to the process that creates a physical part from acquiring the surface data of an existing part using a scanning device. In recent years, as the non-contact type scanning devices become more popular, the huge amount of point data can be obtained with high speed. The point data handling process, therefore, becomes more important since the scan data need to be refined for the efficiency of subsequent tasks such as mesh generation and surface fitting. As one of point handling functions, the cross-sectioning function is still frequently used for extracting the necessary data from the point cloud. The commercial reverse engineering software supports cross-sectioning functions, however, these are only for cross-sectioning the point cloud with the constant spacing and direction. In this paper, adaptive cross-sectioning point cloud which allow the changes of the spacing and directions of cross-sections according to the constant spacing and direction. In this paper, adaptive cross-sectioning algorithms which allow the changes of the spacing and directions of cross-sections according to the curvature difference of the point cloud data are proposed.

Reverse Engineering is a procedure where the results of engineering decisions in manufacturing is feedback to the design phase and the knowledge-base is generated from the process know-how to reduce the errors. Since it used to take lots of time and efforts to finalize the machining of dies out of the original CAD design especially for die spotting and try-outs, reverse engineering is important to improve the productivity and quality of the die manufacturing process. In this regard, we developed system to support reverse engineering in machining of stamping dies for auto-body production. They automatically generate the relevant MC programs for a CMM simply with the input of measuring points in CAD environments, and show the CAD model and the results of inspection simultaneously for the ease of comparison. They also help reduce the overall clearance between the lower and upper dies. Applying these systems to the machining process of stamping dies, we could improve the reliability of measuring and get the optimal compensation distance between the two dies. We also analyzed the expected benefits of the system in terms of savings in time and costs.

For estimation manufacturing cost during the early design stage, desingers have to know compositon of manufacturmg cost. Manufacturing cost is summalion of material cost and processmg cost. To be able to control the manufacturmg cost, it is necessary to estimate the costs adequately and to store the cost data in a generic way. a generic system, which is the basis for the control of the production costs, takes into account geometric information, material information, process information and production planning information Manufacturing cost is summation of material cost and processing cost.

This paper deals with the theoretical estimation and its experimental verification of grinding wheel wear in surface grinding process. A theoretical formulation is provided to predict the grinding wheel wear in surface grinding. The associated surface roughness and grinding force are also investigated both theoretically and experimentally. Through a series of simulations and experiments, it is shown that the predictions are in good agreement with the experimental results.

Free-form surfaces arise in shipbuilding, automotive and aerospace industries. Specially compound free-form surfaces so do. Machining complicated products consist of compound surface, it is very important to avold and remove tool interferences. By the way, in compound surfaces the tool interference can occur not only in the tool path direction but also in the other direction. A new tool interference detection and correction using tool interference conditions is suggested to identify and correct the tool interference in compound surfaces.

In this research, a novel sampling strategy for a CMM to inspect freeform surfaces is proposed. Unlike primitive surfaces, it is not easy to determine the number of sampling points and their locations for inspecting freeform surfaces. Since a CMM operates with slower speed in measurement than optical measuring devices, it is important to optimize the number and the locations of sampling points in the inspection process. When a complete inspection of a surface is required, it becomes more critical. Among various factors to cause shape errors of a final product, curvature characteristic is essential due to its effect such as stair-step errors in rapid prototyping and interpolation errors in NC tool paths generation. Shape errors are defined in terms of the average and standard deviation of differences between an original model and a produced part. Proposed algorithms determine the locations of sampling points by analyzing curvature distribution of a given surface. Based on the curvature distribution, a surface area is divided into several sub-areas. In each sub-area, sampling points are located as further as possible. The optimal number of sub-areas. In each sub-area, sampling points are located as further as possible. The optimal number os sub-areas is determined by estimating the average of curvatures. Finally, the proposed method is applied to several surfaces that have shape errors for verification.

Various types of measuring devices are used for reverse engineering and inspection in different fields of industry such as automotive, aerospace, computer graphics, and home appliance. In order to measure a part easily and efficiently, it is important to select appropriate measuring device considering the characteristics of each measuring machine and part information. In this research, an optimal measuring device selection system using neural networks is proposed. There are two major steps: Firstly, the measuring information such as curvature, normal, type of surface, edge, and facet approximation is extracted from the CAD model. Second, the best suitable measuring device is proposed using the neural network system based on the knowledge of the measuring parameters and the measuring resources. An example of machine selection is implemented to evaluate the performance of the system.

This paper describes a research on the development of the 3D design automation system for progressive die. Based on knowledge base of expert, this system can carry out design tasks, such as feature recognition of product data, layout design, dre set component design. Easy system user mterface and 3-dlmensional solid modeling could result in time and cost saving.

The measuring method of large object using the pattern matching is discussed in the paper. It is hard and expensive to get the complete 3D data when the object is large or exceeds the limit of measuring devices. The large object is divided into several smaller areas and is scanned several times to get the data of all the pieces. These data are aligned to get the complete 3D data using the pattern matching method. The point pattern matching method and transform matrix algorithm are used for aligning. The laser slit beam and CCD camera is applied for experimental measurement. Visual C++ on Window98 is implemented in processing the algorithm.

In thls paper, a remote machine monitoring system for a vimal machine is proposed. The monltonng system is one of the core functmns of a vimd machne that provides a modeling and simulation environment for machining processes and management of the machine life cycle. The proposed system contains the modules for investigating tool wear using neural network and web-based real time process monitoring. An example implementation for tool wear and machining status monitoring is illustrated

Die Casting is one of the forming methods to manufacture large number of products with short period time and clean surface by high forming pressure and temperature of cast alloy. Die design is composed of selection of cast alloy, design of die casting product, runner and gate design etc. In reality, however, die design of die casting has been performed by trial and error method, which cause economic and time loss. This paper describes a research work of developing computer-aided design of die casting product and die design. Approach to the CAD system has been written in AutoLISP on the AutoCAD with personal computer. In this study, die design system for gate of die casting process has been developed to present algorithm for automation of die design, especially runner-gate system. As forming process and die design system using 3-D geometry handling are integrated with technology of process planning, die design is possible to set. In addition, specific rules and equations for the runner-gate system have been presented to avoid too many trails and errors with expensive equipment. It is possible for engineers to make automatic and efficient die design of die casting and it will result in reduction of expense and time to be required. An example is applied to cap-shaped casting using proposed algorithm.

In the previous report1), the grinding characteristics of quartz were investigated. In this paper, the grinding mechanisms of brittle materials including ceramics and quartz are modeled and a new parameter SDR(Surface roughness Direction Ratio) is proposed to characterize the grinding mechanisms of such materials. A set of experiments were performed to verify the effectiveness of the suggested parameter. The experimental results indicate that the plastic deformation is the dominant material removal mode at the grinding conditions which show the higher value of SDR. In the case of quartz, the material was removed by brittle fracture in a lower value of SDR and by plastic deformation in a higher value of it. SDR is not affected by wheel mesh size when brittle fracture occured. But in the plastic deformation case, SDR value increases with wheel mesh size.

Study of Weldment fracture behavior mcludes thermal analysis, residual stress analysis, and fracture analysis The 1-integral loses its path-independency in a res~dual stress field Therefore, it id necessary to develop a program to calculate the J-integral in a welded plate. m this study, theoretical formulation and program were developed for the evaluation of the 1-integral at the crack tip o i weldments. To verify equations and program, welded thin plate and thick plate were used to calculate residual stress and the J-integral.

Dimensional accuracy and surface quality are very important in rapid prototyping especially when the models are used for the production of tools. This paper presents the development of benchmarking part to investigate dimensional accuracy and surface finish. A new test part is designed to perform benchmarking of major rapid prototyping processes such as selective laser sintering, laminated object manufacturing, stereolithography apparatus, and fused deposition modeling. The test part design includes basic manufacturing features such as holes, walls, squares, cylinder and etc. In addition, the small features are included in order to evaluate the fine details that can be manufactured by a specific RP process. The CMM program that automatically measures different features in the test part is also developed. The evaluation of accuracy as well as surface roughness are discussed for major rapid prototyping processes.

One of the major drawbacks of the existing facility layout methods is that most of them were developed based on pre-defined cost functions, and therefore fail to cope with the dynamic aspects of modern manufacturing systems. Another drawback is that due to the poor representation capability of the block diagrams, they are not able to convey the sufficient information needed by facility designers. In this paper, a system for solving facility layout problem considering these matters in cellular manufacturing environment is proposed and implemented using GA approach with embedded simulation module and virtual reality technologies.

Rapid prototyping for welding and milling is a hybrid approach that makes use of welding as additive and conventional milling as subtractive technique. For two years this concept has been used to verify manufacturing mold and mechanical parts successfully. In latest new fabrication methods. For example, manufacturing mold for two sort of materials and shell fabrication, have been applied to the concept in KIST. This methods will be an alternative proposal in rapid prototyping. Metal deposition for welding causes the part to deform. It is a handicap in our proceeding. To overcome this problem, in this paper, we represent an optimal welding path for FEM analysis. Eight paths are tried to this and the value of deformation is average and standard deviation in four points'. Then we can compare with eight cases and select the optimal path.

In this paper, a redesign of computer case is proposed by applying some guide lines of assembly and disassembly to an existing computer case. Some problems such as increase of number of disassembly and vibration, difficult assembly and disassembly from unfittable covers are recognized through analysis of geometrical structure and practical assembly and disassembly. A solution of these problems is proposed through ideas of ease of assembly and disassembly. Design for Environment Software is used to evaluate both redesigned and existing products. Time of assembly and disassembly and MET-point are especially calculated by the software, and these data give us a good guide for analysis of ease of assembly, ease of disassembly and environmental influence in both products.

Intelligent agents represent parts and manufacturing resources, which cooperate, negotiate, and compete with each other. The negotiation between agents is in general based on the Contract-Net-Protocol. This paper describes a new approach to negotiation-based job shop scheduling. The proposed method includes multi-negotiation strategy as well as single-negotiation. A case study showing the comparison of various negotiation strategies is also given.

A dimensioning system in a manufacturing process is often complex, especially when a lot of operations are involved in the process. Determination of operational dimensions and tolerances becomes even more complicated if there exist inconsistencies between operational and design relationships among operational dimensions in machining. This chart furnishes a record of the relationships in an easy-to-grasp form, proves that sufficient stock for a cut is available even under adverse conditions, and also proves that separate operations, when taken together, will harmonize as desired. In this paper, various existing roles of the chart have been extended to an operational routing sheet by generating it automatically, providing machining conditions, and verifying operational tolerances.

To reduce the leadtime for a new model according to the strict market requirements, automobile manufacturer begins to utilize 3-dimensional CAD based techniques such as DMU(Digital Mock-Up). RP(Rapid Prototyping), VE(Virtual Engineering). But, not so many satisfactory utilities have been introduced to deal with the emotional properties such as embossment on the surface of interior parts and touch from material characteristics in virtual environment. It is required to manufacture prototype parts to verify actual feeling of the passengers in real automobile. This paper suggests a methodology to enhance emotional property via embedding embossment on the surface of prototype car interior trim without deterioration of dimensional accuracy using RIM(Reaction Injection Molding) and vacuum forming method.

Rapid Prototyping(RP) techniques have revolutionized traditional manufacturing methods. These techniques allow the user to fabricate a part directly from a conceptual model before investing in production tooling and help develop new models with significant short time. This paper suggests to new process to manufacture large size hollow shape parts for prototype-car using Rapid Prototyping technology and Vacuum Molding with the reduction of delivery time. In addition, This paper introduces the dividing and combining method to make large size RP master model in spite of the limit of the build chamber dimensions of commercialized RP system and post-processing method to achieve sufficient surface quality.

ESO(Evolutionary Structural Optimization) method is known that elements involved low stress value are removed from the previous model or that elements are added around elements involved high stress level on it and then the optimized model is obtained with required weight. Rejection ratio/addition ratio and evolutionary ratio are predefined and elements having lower/higher stress than reference stress, which average Mises stress on edge elements times rejection ratio, are deleted/added. In this study, when the plate having a cutout is subjected various in-plane load, a cutout shape is optimized using ESO method. ANSYS is used to analyse a finite element model and optimization procedure is made by APDL (ANSYS Parametric Design Language). ESO method is useful in rather than a complex structure optimization as well as a cutout shape optimization.

Recently, the life cycle of products is rapidly shortened and then the W s a l of the used mold applied in development of a product is a difficult things. In this study, we proposed a feasibility of the recycling mold base by analyzing of the existing standard mold base. And we developed a D/B program to promote the mold design capability with CAD. Also, we confirmed the possibility of recycling mold base by testing of a used automobile lamp mold.

The dimensional accuracy of the cold forged part is depended on the elastic characteristics of the die. To obtain the high stiffness of the prestressed die, the first stress ring of the tungsten carbide material is considered. For the design, Lam 's equation is used. The design of the prestressed die has been compared with the conventional that. For the comparison, the FE-analysis using ANSYS has been performed. The results indicate that the prestressed die with the high stiffness can be obtained by the using the high stiffness material as the first stress ring.

Multi-disciplinary optimization design concept can provide a solution to many engineering problems. In the field of structural analysis, much development of size or topology optimization has been achieved in the application of research. This paper demonstrates an optimum design of a multi-layer cylindrical tube which behaves thermoelastically. A multi-layer cylindrical tube that has several different material properties at each layer is optimized within allowable stress and temperature range when mechanical and thermal loads are applied simultaneously. To analyze these problems using an efficient and precise method, the optimization theories are adopted to perform thermoelastic finite element analysis.

During the deep drawing process an initially flat blank is clamped between the die and the blank holder after which the punch moves down to deform the clamped blank into the desired shape. In general, sheet metal forming may involve stretching, drawing, bending or various combinations of those basic modes of deformation. The deformation problems of sheet metal working involve non-linearity in geometry and material. In this work, The punch load and thickness strain of electro-galvanized sheet steel (SECD) for elliptical deep drawing are examined under the various process conditions including, punch shape radius, die shape radius. The changes of punch load and thickness strain distribution of the deformed elliptical cup are affected by the size of each die shape radius.

This paper presents a performance Analysis of electrically exhaust gas recirculation valve using commercial electromagnetic simulation software, Flux2D. Under the assumption of 2D axi-symmetric magnetic field, the characteristics of EEGR valve by revising the design parameter, has ken investigated by estimating the variation of thrust force with respect to the pintle position. The mode shapes and the frequency response functions were computed by using three dimensional finite element modeling of the whole EEGR valve and their accuracies were verified with experimental FFT analysis technique.

Spent fuel rod cutting device should cut a spent fuel rod to an optimal size in order to fast decladding operation. In this paper, for developing spent fuel rod cutting device with cutter blade, rod properties such as dimension and material of zircaloy tube and fuel pellet are investigated at first and then, various methods of existing cutting devices used commercially are investigated and their performance are analyzed and compared. This device is designed to be operated automatically via remote control system considering later use in Hot-Cell (radioactive area) and the mdularization in the structure of this device makes maintenance easy. SUS and Zircaloy-4 are selected as cut material used in the test of spent fuel rod cutting device by cutter blade. In order for constructing the high durable cutter blade, various materials are analyzed in terms of quality, shape, characteristic, and heat treatment, etc. and from these results, spent fuel rod cutting device is designed and manufactured based on the considerations of durability, round shape sustainability of rod cross-section, debris generation, and fire risk, etc.

The demands of high data transfer rate and high recording density in optical disk memory device are being increased. In order to achieve high performance, lever actuator for optical disk is proposed. Firstly, the role of lever and structure are discussed and the flexure hinge is introduced to enhance the precise movement. Next is to present the magnetic circuit structure and concept design for the lever actuator. Finally, the dynamic modeling of the lever actuator is found and the analysis results are shown. Consequently, the lever actuator shows the possibility as a pickup actuator for the next generation optical disk.

Fault tree analysis (FTA) is a widely used methodology for reliability analysis. The method is useful in that it suggests a very comprehensive way of describing the hierarchical relations of causes of faults and the corresponding results. However it is difficult to get appropriate fault trees for given products or systems without very profound knowledge and experience. This work aims to develop a methodology of fault tree construction using the results of function deployment for machine parts, which provides an objective way of preparing fault trees. The failure modes are defined to each function network generated by the function deployment method and the fault tree with respect to each viewpoint is constructed by arranging the failure modes. The fault tree is finally obtained by synthesizing the fault trees with respect to each viewpoint. The example of fault tree construction is also shown.

Much research efforts have been made on the structure and properties of metals deformed to severe plastic deformation (SPD). Being deformed to SPD, ultra-fine grains (UFG) are usually formed, and UFG structure exhibits fundamental differences in original physical properties. One method often used to obtain SPD is equal channel angular pressing (ECAP). In order for this technique to be exploited, it is important to understand the deformation behavior during the ECAP processing with respect to friction. The finite element method (FEM) has been used to investigate this issue.

The spent fuel skeleton is processed in the cutting processing after compacting. If the cutting length is processed in the same interval length. The spent fuel skeleton is stayed on the connection of bottom nozzle and guide tube. In the case, because the compressive stress is loaded along the length, the guide tube is generated the buckling stress and the deforming. But the deformed guide tube interrupted the guide tube inserted through compressive room. therefore, it is experimented for the optimum buckling stress and the preventing of guide deformed. This paper is predicted the all over buckling stress of the spent fuel skeleton by using experiment. The guide of Spent fuel skeleton have buckling characteristics of the medium column. The experiment and analysis is conducted by the comparing among the equation of Euler, Johnson and Engresser. The fittest one of method is Engresser equation.

The theoretical analyses for stresses induced in axial direction in the buried pipelines are reviewed. The influences of the axially directed stresses on the surface elliptical crack are studied in detail and thus some engineering technical informations are provided to use reliability assessment of buried pipelines. The change in temperature, the effect of inner pressure and soil friction in the buried pipeline constrained in axial direction are included to determine the axial stresses in the buried pipeline. Furthermore, the stress induced by the pipeline bending are also considered. The stress intensity factors calculated by two models such as a simple plane crack and an elliptical surface crack for a circumferential surface elliptical crack are compared.

Valve springs with high fatigue strength corresponding to the incresement of working stresses, are required for the higher generating power and the better fuel economy of automobile engines. For this purpose, high strength oil tempered wires are being used. By a method of the high strength for the valve spring, modification of manufacturing processes is being applied. In this case, the cause and effect for the improvement of the fatigue strength has not yet been explained obviously. Therefore, in this report, comparison of fatigue life between valve springs of conventional processes with oil tempered wires and new manufacturing processes was made. As a result of the fatigue test, the fatigue life of the latter was attained maximum 7 times than that of the former. It was cleared that the improvement of the fatigue life was caused by difference of compressive residual stresses at depth of 0.2mm below the inner side surface of both valve springs.

In this paper the impact force which occurs on each tooth of jaw-bones while masticating is calculated through the rigid body dynamic analysis. This analysis is done by ADAMS. The impact force calculated in this paper is required for the structural stress analysis of implant system which is needed for the implant system design. The analysis results show that the impact time decreases as the impact force increases, the largest impact force occurs on the front tooth and the impact force is almost normal to the tooth surface together with slight tangential force.

The dynamic photoelasticity with the aid of Cranz-Shardin type high speed camera system is utilized to record the dynamically propagating behavior of the interface crack. This paper investigates the effects of the hole (existed along the path of the crack propagation) shape on the dynamic interface crack propagation behavior by comparing the experimental isochromatic fringes to the theoretical stress fields.

For a new design of a automotive brake system, it appears to be very important to examine the temperature and thermal stresses distribution in the brake drum. In the direct measurement of them, however, a number of difficulties are involved. In this study, simulation on temperature and thermal stress distributions in an A1-MMC brake drum of a commercial vehicle during 15 braking operations was carried out using the finite element analysis(FEA1. The effect of a circumferential fin near open end of the brake drum on the temperature rise and stresses was also examined.

Composite material consists of more than two materials and make various kinds of composite materials by combining different single materials. Copper clad aluminum composite material is composed of Al and Cu, and it has already been put to practical use in Europe because of its economic benefits. This paper presents the interface bonding according to the variation of extrusion ratio and semi-angle die by observing the interface between Cu and Al using metal microscope. By that result, we can predict the conditions of the interface bonding according to the extruding conditions.

The recycling process for reuse of uranium in the spent fuels consists various unit processes and the decladding process to extract the spent fuel pellet from the zirconium-based cladding is the beginning process of the recycling. There are two methods - mechanical and chemical - in the decladding process. In this paper, the mechanical decladding device by using a motor as a driving part and a press pin to separate the pellets from tube has been developed. This device was automated and modularized to make the remote operation and maintenance easy.

In this paper, a numerical method is proposed for cam synthesis. kinematics of closed loop system with cam and follower is presented using relative coordinates. The system is transformed into an open loop system by cutting fictitiously higher-pair contact of cam and follower and envelope constraint equations are derived. Follower constraint equations are derived from the motion of the follower ends. The joint variables and follower profile parameters are calculated from the envelope constraint equations and follower constraint equations by using the Newton - Raphson iterative method. Algorithms for cam synthesis are presented and simulations are done to verify the effectiveness of the proposed method.

This paper presents experimental results on selecting optimal process parameters for UV-Vaccum casting. The UV-Vacuum casting is a relatively new process that allows very rapid mold preparation and part duplication via UV curing. Effect of various process variables such as pressure and temperature on mold strength and part accuracy was evaluated by using Taguchi method.

Injection molding is the most widely used process for the industrial forming of plastic articles. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation·orientation and infection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of welding parts in injection-molded products is assessed. And the effects of fiber content and injection mold shapes on the fiber orientation in case of fiber reinforced polymeric composites are studied. experimentally.

A branched crack in a semi-infinite plate under tension and bending moment is considered. Intensity factors of the stress and moment for the branched crack are evaluated. The stress intensity factors are obtained by using the finite element method and the J-based mutual integral. The moment intensity factors are calculated by extrapolating the values of the moment near the crack tip. Approximate expressions are also obtained as functions of the branched crack length and branching angle.

The procedure of semi-solid forming is composed of heating a billet, forming, compression holding and ejecting step. There are several methods to heat a billet during semi-solid forming process such as electric heating and induction heating. Usually in semi-solid forming process, induction heating has been adopted to achieve more uniform temperature of semi-solid material. Although induction heating is better method than any others, however, there is still difference of temperature between internal part and surface part of semi-solid material. Worse yet, in case of high liquid fraction of semi-solid material, liquid of the billet will flow down though solid of the billet still remains, which is very difficult to handle. In the present study, induction heating of semi-solid material with compulsive surface cooling has been performed to obtain uniform distribution of temperature. Distribution of temperature of the billets was measured and compared with that of conventional distribution of temperature. By this new induction heating method, not only temperature over the whole billet become uniform, but also control of temperature is possible.

a crack with electrically impermeable surfaces in an electrostrictive material subjected to uniform electric loading is analysed. A strip yield zone model is employed to investigate the effect of electric yielding on stress intensity factor. complete forms of electric fields and elastic fields for the crack are derived by using complex function theory. /the stress intensity factors are obtained based on the strip yield zone model.

Recently, many studies focus on mixed-mode fatigue-fracture characteristics of characteristics of materials. In order to reveal crack initiation and propagation mechanisms in combined -mode fatigue. This paper investigates the initiation and propagation behavior of the fatigue crack of the STS304 specimens under mixed mode loading conditions. moreover crack arrest and branch phenomena were analyzed with respect to the change do the angle of inclined loading. The relationship between the angle of inclined loading and the angle of branched crack was studied. A greate number of cycles are necessary to initiate a new crack from the initial crack. The direction of the new crack propagation is determined by MTS theory.

It is useful way to make indentations near crack tip in order to increase fatigue life or repair a fatigue crack. In this study, bending fatigue tests were performed to investigate the optimal position of the indentations near crack tip. The results shows that fatigue life of the specimen is dramatically increased by indentation and the most effective location is the back of the crack tip.

Practical structures are subject not only to tension but also to shear and torsional loading. Even under uniaxial loading, when the load is not perpendicular to the crack plane, mixed mode crack can occur. Hence, it is necessary to evaluate the fatigue behavior under mixed mode loading. In this study, the propagation behavior of the fatigue crack of the STS304 steels under mixed mode loading condition was investigated. The mode I and II stress intensity factors of CTS specimen were calculated using elastic finite element method with experimental results. The fatigue crack propagation under mixed mode was evaluated by the effective stress intensity factor proposed by Tanaka.

In this study, the fatigue characteristic of spot weld specimen was studied by using the various specimen. The specimen types were tensile shear specimen welded one spot and two spot, and cross tension. The tensile tests and fatigue tests were executed to know the mechanical properties under static and fatigue load condition. In addition, the relationship was illustrated by finite element method.

Turbine blade has trouble of cracking at root region. Fracture surface of blade root is surveyed by SEM and AFM to clear relation between fracture mechanical parameter and surface parameter (striation width and surface roughness). Service stress is predicted by maximum height roughness $R_{max}$, on fractured surface and stress analysis on turbine blade. It is to thought that turbine blade is fractured by abnormal condition such as incorrect fittings between pin and pin hole but isn't fractured by normal service conditions such as steam pressure, centrifugal force and torsional force.

This paper presents the fine-shearing experimental investigation using brass sheets. Shearing including blanking, trimming, piercing, etc is one of the most frequently used processes in sheet metal manufacturing. In this study, an individual set of tooling was designed and fabricated to carry out experiment for shearing process. In order to investigate the effect of shearing surface correspond to die clearance, the profile of shearing surface was examined by using microscope. Futhermore, the relationship between shearing force and the profile of shearing surface was considered.

Air dynamic bearings are inherently unstable in dynamic behavior due to the varying angle of a force produced and the nonlinear characteristics of stiffness. In this study, such dynamic behavior is obtained and compared with experimental results. A body axis coordinate system is employed to avoid the change of a moment of inertia. FDM is used to calculate the pressure distribution on the bearing surface and then the force acting on the rotor was calculated by integrating the pressure distribution. By integrating accelerations which are calculated from the equations of motion using the 4th order Runge-Kutta method, the pose of the bearing at each time step is obtained.

In this study, an experimental method measuring the scroll under the temperature distribution similar to the operating condition is proposed and the results are presented. Direct measurement of the actual thermal stress is very difficult because of the rapid and complex motion of the orbiting scroll. Therefore, the experimental condition is provided on the stationary scroll heated in the electric furnace and, then, the mechanical stress and the effects of refrigerant are excluded from the resulting measurement. The experimental results are compared with these of FEM, both showing good agreement.

The ob.jective of this study is to determine fracture behaviors(penetrati0n modes) and resistance to penetration duringballistic impact of Al 5052-H34 alloy laminates and anodized Al 5052-H34 alloy laminates. Resistance to penetration is determined by $V_{50}$ ballistic limit, a statical velocity with 50% probability for complete penetration, test method. Fracture behaviors and ballistic tolerance, described by penetration modes, are respectfully observed that result from V50 test and Projectile Through Plates (PTP) test at velocities greater than $V_{50}$. PTP tests were conducted with 0" obliquity at room temperature using 5.56mm ball projectile. $V_{50}$ tests with 0" obliquity at room temperature were conducted with projectiles that were able to achieve near or complete penetration during PTP tests. Surface Hardness, resistance to penetration, and penetration modes of A1 5052-H34 alloy laminates compared to those of anodized Al 5052-H34 alloy laminates.y laminates.

This paper presents the analytical studies on the stress and strain of driven valve system of internal combustion engines. The stress and strain is predict using FEM. The particular interest is the dynamic strain at a specific point of the valve and valve seat. Cam and follower Assuming that one rigid surface. This study forced the effects changing Young's modulus and density of valve and valve seat contact area. It supports that the indirect method using FEM is reliable for prediction the actual displacement, stress and strain in the valve system.

When a body including a crack inside is subjected to the compressive forces, the crack is closed and sliding occurs on the crack surfaces. In this work, a subsurface crack subjected to a static or moving compressive load is analyzed with the finite element method considering friction on the crack surface. The friction on the crack surface is assumed to follow the Coulomb friction law. A numerical method based on the finite element method and iterative method is applied in this work. And the result is compared with the frictional contact of crack by ANSYS using contact 12 element. The numerical results of two methods are compared with the wellknown analytical solutions, and the accuracy of iterative method is checked..

This paper performs the motion analysis for a disk cam and a follower mechanism using a circular arc method, a coordinate transformation method and an instant velocity method in order to find a contact point between the cam and the follower. Based on the proposed method, the displacement and the velocity are calculated by using the geometric relationships of the cam mechanism. Also, the acceleration is determined on using the central difference method. As the results, this paper presents the original curve and the analyzed curve for the motion analysis of the disk cam for an example.

The armor composite material targets such as aramid FRMLs with different type and ply number of face material and different type of back-up material, were studied to determine ballistic impact resistance and dynamic failure behavior during ballistic impact. Ballistic impact resistance is determined by $\textrm{V}_{50}$ ballistic limit, a statical velocity with 50% probability for complete penetration, test method. Also dynamic failure behaviors are respectfully observed that result from $\textrm{V}_{50}$ tests. $\textrm{V}_{50}$ tests with $0^{\circ}$ obliquity at room temperature were conducted with projectiles that were able to achieve near or complete penetration during high velocity impact tests. As a result, ballistic impact resistance of anodized Al 5052-H34 alloy(2 ply) is better than that of anodized Al 5052-H34 alloy(1 ply), but Titanium alloy showed the similar ballistic impact resistance. In the face material, ballistic impact resistance of titanium alloy is better than that of anodized Al 5052-H34 alloy. In the back-up material, ballistic impact resistance of T750 type aramid fiber is better than that of CT709 type aramid fiber.

Ductile fracture of dual phase steel begins with void nucleation, at martensite-ferrite interface of deformed martensite particle. In this study, void nucleation, growth, and coalescence under various strain were studied in dual phase steel. Therefore, by means of the heat treatment of low carbon steel, the study deals with void nucleation and growth for ferrite grain size and martensite volume fraction of dual phase steel using statistical method. Void nucleation and growth with increasing strain are shown depend upon the ferrite grain size. Voids volume fraction generally increase as ferrite grain size decease.

In this paper, the influence of circular void on a crack in piezoelectric materials under mechanical and electric loads is investigated by using finite element method code, ANSYS. Both ceramics and piezoelectric materials are compared with stress intensity factor and crack extension force at crack tip on arbitrary located circular void under Mode I loads. It was found that piezoelectric materials's crack extension force is larger than ceramics.

Static and dynamic experiments were done to study on the restitution behaviors of strings. The elastic and viscoelastic model were compared. To apply a linear viscoelastic model (Kelvin model) to longitudinal behaviors of strings, static and dynamic tensile tests were done. Using their results, it should be intended to acquire damped stress (Stress related to velocity), and to calculate the viscoelastic coefficient. Fixing both ends, string was pushed by the loadcell attached to the tensile tester. The experimental results were in accordance with the calculated results using the Kelvin model acquired from the results of longitudinal tensile test. But the results of falling mass experiments, the behaviors of strings were near to elastic model. The clamping condition of strings in both sides has an effected on the value of COR. The smaller contact area, the grower the value of COR.

The steel pipe for fluid catalytic cracking(FCC) unit. petroleum refinery, is lined with refractory to protect the system from high-temperature of the internal flow. The property of the refractory has an effect upon the stress analysis of FCC unit. Because 1-D pipe element or 3-D shell element are usually used in commercial codes of stress analysis to evaluate the structural soundness, the equivalent elastic modulus considering steel and refractory should be applied. In the research, the theoretical method to obtain the value of the equivalent property is introduced and then the stress analysis is carried out with the part of FCC unit.

Alignment system is a system to locate an object to it's accurate position in multi-d.o.f space. According to process of application, it is need to align an object in 3 or 6 d.o.f. space. And alignment system is used in various environments. Especially in PDP application, alignment process is carried out in vaccume environment. In this paper, we developed 3 d.o.f. alignment system for vaccume environment, performed kinematic analysis and improved it's positional accuracy.

Conventional aerodynamic simulations have carried out by using Supercomputer and over a hundred grid point or wind tunnel experiment. It takes s long time to get a result. This paper has dealt on flow characteristics of automobile in the flow field. CFD(Computational Fluid Dynamics) has been able to apply to industrial field in these days. This new method has been applied to the aerodynamic simulation system, a designer has been able to carry out the practical on early designing phase of automobile. This paper has been focused on the necessity of rear-spoiler, the peculiarity of aerodynamic drag, and the level of drive safety.

Bending is one of the most common cold-stamping operations, recently it is many used to produce structural frame. Depending on the shape and dimensions of complex structural frame, a successive bending operation with simple dies may be economic. But, in this paper, it has been focused to reduce the bending operations by a successive-action compound die. Designed compound-die consists of blank-holder, cam, wedge and etc. In the result, this compound-die for structural frame enabled that it makes seven bending processes into one process, and improved productivity.

Recently vehicle development trend puts emphasis on cost reduction and performance improvement through weight reduction, and safety security to protect passenger and chassis against external impact. Primary factors effected on vehicle safety are chassis structure, chassis system, and safety equipment like bumper. Research in part of weight reduction is proceeding actively about prohibition of over-design and material through optimal design method. Bumper in these factors is demanded two of all factors, safety security and weight reduction. It is the part that prohibits or reduces a physical impact in low speed crash. Bumper is composed of a few parts but this study exhibits the shape of bumper rail has a role on energy absorption of safety security and weight reduction from structure analysis of bumper rail's variable shape surface.

Optimization of structure of a high-precision stamping press structure is performed by combination of Taguchi Method and finite element analysis. Too much difference in the stiffness between hydrostatic bearing linear guide and press structure is observed. Efforts are made to level up the stiffness of press structure to the level of hydrostatic bearing's. Some important design parameters are identified and discussed.

Seals in universal joint bearing are a important component reinforcing lubrication performance by holding a lubricant and preventing infiltration of dust, moisture, etc. There is a great difference in seal performance according to seal shape and bonding position. Therefore, in this study, as for the lib type seal and O-ring type seal, FEM analysis are conducted using Mooney-Rivlin Model. The results are indicate that O-ring having higher contact stress and larger contact area than lib type is more profitable.

Die design to minimize the die wear in the cold forging process is very important as it reduce the production cost and the increase of the production rate. The quantitative estimation for the die wear is too hard because the prediction of the die wear is determined with many process variables. So, in this paper, the optimal shape of the backward extrusion punch is newly designed through the FE-analysis considering the surface expansion and Archard's wear model in order to reduce the rapid wear rate that is generated for the backward extrusion product exceeding the forming limit. The main shape variables of the backward extrusion punch are the flat, angle, and round of the punch nose part. As the flat and angle of the punch nose are larger, the surface expansion is reduced. and, the wear rate is decreased according to the reduction of the punch round. These results obtained through this study are applied to the real manufacturing process, it is implemented the reduction of the wear rate.

In this study, we investigate several problems of previous workflow system, and suggest an enhanced process management system that involves a substantial portion of workflow system. To overcome the differences in systems, we selected a web as platform to develop a process management system, and we investigate merit and capability of web-based process management system. We improved WFMS's ability to define various process through many behavior rules and multiple layered process structure. We suggest X-WPM system for the process management system with XML technology.

This work ethibits how susceptive the shear ultrasonic waves are to a little misoriented plies according to the angle variation of shear ultrasoic waves $0^\circ$ , $45^\circ$ and $90^\circ$. Also, it is shown that shear waves, particularly the transmission mode with the transmitter and receiver perpendicular to each other, have high sensitivity for detecting anomalies in fiber orientation and ply layup sequence that may occur in the manufacturing of composite laminates. Experimental results are agreed with modeling solutions which were based on decomposition of shear wave polarization vector as it propagates through the composite laminates. This wave appeared considerably to be sensitive to CFRP composites to the thickness direction along in-plane fibers.

The new core making method economized on core sand requested. The new method is heating core box until it reaches reasonable temperature and then spraying core sand with core binder into core box. Inner temperature distribution have to uniform in order to form core of uniform thickness. Therefore, in this study we treat of inner temperature distribution of core box in priority. First, determine proper torch number. Next, optimize the torch position to minimize the average of absolute deviation(AVEDEV) of inner temperature. The results are as followed : 1. The torch number that makes inner temperature distribution about $300^\circ{C}$ uniformly is 25. 2. When $S_H$ and $S_V$ is 0.7, the torch position is optimized and AVEDEV is 5.85.

This paper describes a research work of developing a computer-aided design of product with bending and piercing for progressive working. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, strip layout and die layout module. Based on knowledge-based rules, the system is designed by considering several factors such as radius and angle of bend, material and thickness of product, complexities of blank geometry and punch profile, bending sequence, and availability of press. Strip layout drawing generated by the piercing processes with punch profiles divided into for external area is simulated in 3-D graphic forms, including bending sequences for the product with piercing and bending. Results obtained using the modules enable the manufacturer for progressive working of electronic products to be more efficient in this field.

This paper describes an Axiomatic Design Process enhanced by the Combinative Index that represents combinative strength between function requirements and design parameters. This method combines the advantages of these two methods : 1) Combinative Index that represents combinative strength between function requirements and design parameters so that we clearly understand these information. 2) engineering specifications are categorized into strategies, constraints and Functional Requirements. In this paper, relationship of FR's and DP's is regarded as one in which uncertainty of information are fundamentally involved. In the reduction of problem with uncertainty, we propose an enhanced Axiomatic Design Process using Combinative Index.

In the high carbon steel wire drawing process, the wire temperature increases as the drawing speed is faster in order to increase the production rate in the shop floor. The rapid temperature rise causes the wire fracture in the dry wire drawing process. So, in this paper, the isothermal pass schedule program, which includes the calculation method of wire temperature at each pass, is proposed to prevent the wire fracture due to the temperature rise. Using the isothermal pass schedule program, it is newly proposed the pass schedule design system that prevents the cup-cone defects, improves the elongation of the final products and assures further deformation. As a result, the temperature rise of the wire was decreased and the production rate of the final product is remarkably grown up according to the increase of the final drawing speed than that of the conventional process. Also, the proposed pass schedule design system could give a useful information to the process designer who would design the high carbon steel wire drawing process.

All of rubber tubes for force pump are imported from aboard there for locallization of these tubes is make a great contribution of Korean industry In this study compare with existing product of japan and designed the new one that is for our actual circumstances. Experimental work was performed to two kinds of specimen and compression test is performed for them. As a result specimen type A has a better restoration than other and minimum thickness is must over 12mm.

This study is for stabilizer, a parts of automotive suspension system, that would be changed to Plastic Material. The part is designed and analyze by PRO-E. The position of Weld Line is founded by the C-mold, computer software with FEM. Then a Mold is designed by consideration with locating Weld Line. Mechanical property tests, such as tensile test, compression test, ball pull-out test, fatigue test and durability test are done the part by SAE test spec. Most of all the result of the tests show over requirement result without the compression test.

Cam mechanism is one of the common devices used in many automatic machinery. Specially cylindrical cam generates three dimensional motions. Thus, the shape design procedures must have high accuracy. This paper proposes the shape design procedure for a cylindrical cam and follower mechanism using a relative velocity method. The relative velocity method and the coordinate transformation are used to find a contact point between the cam and the follower. Also, the full shape of the cylindrical cam can be generated by using the geometric relationships and the contact constraints. As a result, this paper presents an example for the shape design of the cylindrical cam in order to prove the accuracy of the design procedures.

The optimum design of a structure requires to determine economical member size and shape of a structure which satisfies the design conditions and functions. In this study, it is attempted to minimize a dead weight of the bogie frame. Therefore, shape optimization is performed for a bolster rib at first and then size optimization for the thickness of top and bottom plate. For the efficient reduction of a weight of a bogie frame, various ellipses centered at a centroid of a bolster rib are made and tried. For the shape optimization, a major axis and an eccentricity of an ellipse are chosen as design variables. From the numerical results of shape and size optimization of a bogie frame, it is known that the weight can be reduced up to 12.476 Y4717.21 kg) with displacement and stress constraints.

The leaf spring is generally used effectively in load supporting because it has tension-diffused function in comparison with other springs. Nowadays the leaf spring is used widely in the suspensions of automobile and trains. The stiffness and the damping characteristics of the leaf spring being essential for the performance of vehicles, the exact evaluation is required. Various approximate formula are normally used for the leaf spring design. however, accuracy and trust are decreased because the contact and frictional characteristics between leaf plates are generally neglected. In this paper, nonlinear stiffness matrix of the leaf spring is solved by contact-element applying FEM for considering the contact and frictional characteristics between leaf plates. The results of proposed FE model are compared with test data.

This paper describes a local modification capability on shell meshes, which can change a 'constant or variable radius of rounding for the s h q edges of the stamping die shoulder in the mesh. The algorithm consists of the followin_e three main steps; (1) the rounding area for sharp edges of a die shoulder are detected from the given shell mesh, (2) a rolling-ball surface with a given constant or variable radius is generated, which is contacti% with two incident face groups of the sharp edges, (3) the rounding area of the mesh is cut off, and a new mesh for the rolling-ball surface is generated and implanted into the gap. Owing to this rounding modification capability, CAE engineers can examine various cases based on the existing dies by scanning them to form polyhedral models and then changing radii of die shoulders for stamping process simulation.

In the recent day, shielding can was made of permalloy materials for automobile display instrument. The good roundness has an effect on magnetic property such as the low coercivity and the high permeability. But the products having the roundness is transformed by the heat treatment, the sending to the company and the assembly process. So for the stiffness of the edge, it is necessary for hemming process to be added in the deep drawing process. And it has the good appearance to create a smooth edge rather than a razor edge with urr. In this paper, it is controlled to get the best hemming product by the Pre-hemming angle($105^{\circ}$, $120^{\circ}$, $135^{\circ}$). And Possible process and tool design modification, which may lead to quality improvement in hemming were tested experimentally and using FEM. The commercial finite element program PAM-STAMPTM was used to simulate the pre-hemming process and hemming process, and the predictions were compared with experimental results according to the pre-hemming angle.

It is necessary to work on a vertical plane of workpiece in order to produce a large structure like a ship. These works can be automated by using the robot with permanent magnet wheels. We developed the permanent magnet wheel which can be used by a mobile robot and easily detached. We enhanced an adhesive power by restricting the occurrence direction of magnetic flow. And we also developed a method which weakens adhesive magnetic force by changing magnetic flow with metal pins. We used the load cell and the gaussmeter to measure the characteristics of the adhesive force and magnetic force. We obtained the result that the adhesive power is reduced to 1/3 of normal state by using 4 inducing pins.

In this study, we constructed a preview-sensing visual sensor system for weld seam tracking in real time in GMA welding. A sensor part consists of a CCD camera, a band-pass filter, a diode laser system with a cylindrical lens, and a vision board for inter frame process. We used a commercialized robot system which includes a GMA welding machine. To extract the weld seam we used a inter frame process in vision board from that we could remove the noise due to the spatters and fume in the image. Since the image was very reasonable by using the inter frame process, we could use the simplest way to extract the weld seam from the image, such as first differential and central difference method. Also we used a moving average method to the successive position data of weld seam for reducing the data fluctuation. In experiment the developed robot system with visual sensor could be able to track a most popular weld seam, such as a fillet-joint, a V-groove, and a lap-joint of which weld seam include planar and height directional variation.

This paper presents a study on the position tracking control of robot system on the uncertain elastic base. The elastic base is modeled as a virtual robot which has passive joints and the control strategy is using approximate Jacobian operators. Jacobian operators represent the overall robot system including base movement. However, because we don't know the base movement we can't estimate the jacobian operators directly. The control algorithm is proposed which uses only Jacobian operators of a real robot as approximate Jacobian operators. The measured errors from external sensor are compensated by approximate Jacobian operators. The simulation results of a single-axis robot system show that the control strategy can be used for position tracking.

The paper describes the contents and results of the national project named "Development of Computer Integrated Product Design for Automation Equipment". It is focussed on the real-time control '||'&'||' monitoring of manufacturing process for automobile rubber parts. Automobile rubber parts industy is one of the typical process that high11 depends upon manufacturing facilities and equipments. So. it requires high cost and engineering technolog) on plant implementation. But most companies of rubber parts industries are small or mid companies that habe weak abilities for plant implementation properly and systematically. Therefore, for upgrading the levelof automation. it is necessar). to dekelope the computer based management and monitoring slsteni that enables to build-up the common base of automation and systemization. 'Through this project. we developed low cost real-time monitoring system for banbun mixing process '||'&'||' mold injection process of rubbcr parts manufacturing, that is composed with DDCU(Distributed Digital Control Unit),signal interfaces to gathering mon~toring terms and speciall\ developed functional sofhare including some algorithm for management '||'&'||' process monitoring

In this study, the control of mounting system for MLGA package was developed using machine vision for the control of rotating position compensation and mounting position of X-Y table. Two type of material (polymer, alumina )were used for the dielectric insulator of the MLGA. And the illumination system and the algorithm of position compensation that be suitable for these materials was developed. Also, the position control order that compensated by machine vision actuated to micro stepping motor and X-Y servo motor by controlled PC and mounted the MLGA on PCB in resolution to$\pm10\mum$ .

Localization is the process of aligning the robot's local coordinates with the global coordinates of a map. A mobile robot's location is basically computed by a dead reckoning scheme, but this position information becomes increasingly inaccurate during navigation due to odometry errors. In this paper, the method of building a map of a robot's environment using ultrasonic sensor data and the occupancy grid map scheme is briefly presented. Then, the search and matching algorithms to compensate for the odometry error by comparing the local map with the reference map are proposed and verified by experiments. It is shown that the compensated error is not accumulated and exists within the limited range.

This paper attempt analysis and computer simulation of dynamics of a set of dual multi-joint fingers with soft-deformable tips which are grasping. Firstly, a set of differential equation describing dynamics of the fingers and object together with geometric constraint of tight area-contacts is formulated by Euler-Lagrange's formalism. Secondly, problems of controlling both the internal force and the rotation angle of the grasped object under the constraints of area-contacts of tight area-contacts are discussed. The effect of geometric constraints of area-contacts on motion of the overall system is analyzed and a method of computer simulation for overall system of differential-algebraic equations is presented. Finally, simulation results are shown and the effects of geometric constraints of area-contact is discussed.

This paper describes a remote monitoring and control system using mobile internet environments through TCP/IP. The server program acts as the main interface between the machine system and the internet technology. The client program is to be distributed to the remote users such as PDA who want to monitor the machine status. A server system is designed to send information of the faults and status of application system to the client part. Therefore, The client parts can take measures and control the system remotely according to the error and faults of system. We developed the client- serversystem for remote control of a green house environment.

The purpose of this study is to develop a powerful 6-axes general welding robot utilizing a low cost vision system. The developed vision system is composed of a CCD camera, a PC with windows 98 OS, and a PC-Robot communication program using Visual C++. A test was carried out to investigate whether the welding torch can precisely follow up the welding path. It shows that the result of this study can readily be applied to practical welding operations.

A new approach to the task of aligning a robot using camera is presented in this paper. We apply an elitist GA to find the joints angles of manipulator to reach target position instead of using nonlinear least error method. Since it employs parallel search and have good performance in solving optimization problems. In order to improve convergence speed, the floating coding method and geometry constraint conditions are used. Experiments are carried out to exhibit the effectiveness of vision-based control using elitist genetic algorithm.

Lately, many studies have been progressed for the protection human's lives and property as holding in check accidents happened by human's carelessness or mistakes. One part of these is the development of an autonomouse vehicle. General control method of vision-based autonomous vehicle system is to determine the navigation direction by analyzing lane images from a camera, and to navigate using proper control algorithm. In this paper, characteristic points are abstracted from lane images using lane recognition algorithm with sobel operator. And then the vehicle is controlled using two proposed auto-steering algorithms. Two steering control algorithms are introduced in this paper. First method is to use the geometric relation of a camera. After transforming from an image coordinate to a vehicle coordinate, a steering angle is calculated using Ackermann angle. Second one is using a neural network algorithm. It doesn't need to use the geometric relation of a camera and is easy to apply a steering algorithm. In addition, It is a nearest algorithm for the driving style of human driver. Proposed controller is a multilayer neural network using Levenberg-Marquardt backpropagation learning algorithm which was estimated much better than other methods, i.e. Conjugate Gradient or Gradient Decent ones.

In this paper, a motion control algorithm is proposed by using neural network system, which makes a robot arm successfully avoid unexpected obstacle when the robot is moving from the start to the goal position. During the motion, if there is an obstacle the vision system recognizes it. And in every time the optimization-algorithm quickly chooses a motion among the possible motions of robot. The proposed algorithm has a good avoidance characteristic in simulation.

Round-cornering machines are mainly used for cornering of stiffners for ship buildings. In the present time they have been operated manually by operators. so they are need to be operated automatically without regard to any shapes of stiffners. We developed the automatic round cornering system which consists of CCd Camera, PC and laser diode to detect automatically the edge of stiffners to be processed

The automation and control of robotic welding process is a very complex assignment because the system is affected by a number of variables which are very difficult to determine or predict in practice. Not only the optimization of the robotic welding process is considered from the point of view of the time and the cost of manufacturing. as well as quality of the weldment. the human factors of the production and many other factors must taken into consideration. hi order to determine the optimal parameters of robotic welding process, it is necessary to build a computer model representing all parameters influencing the welding process as well as the mutual dependence between them. This paper presents an approach to modeling the robotic welding process in which all parameters affecting the welding process are included using a neural network. A detailed analysis of the simulation results has been carried out to evaluate the proposed neural network model.

This paper studied on the lateral motion of the gantry crane which is used for the automated container terminal. Though several problems are occurred in driving of gantry crane, they are solved by the motion by the operator. But, if the gantry crane is unmanned, it is automatically controlled without any human operation. Especially, the collision between wheel-flange and rail is a very critical problem in driving of unmanned gantry crane. To bring a solution to these problems, the lateral and yaw dynamic equations of the driving mechanism of gantry crane are derived. And this study used PD(Proportional-Derivative) Controller to control the lateral displacement and the yaw angle. The simulation result of the driving mechanism using the Runge-Kutta method is presented in this paper.

The sway motion of the spreader during and after movement causes an efficiency problem of position control in unmaned gantry crane. The objective of this research is to investigate the phenomenon that the load is taken by the sway motion of crane. For deriving the dynamic equations related to the swing motion of crane, we introduced a conception of spring and damper in the upper part of the crane. During the crane and trolley is driving along the velocity profile, the swing motion of the spreader and crane will be simulated. The simulation result of the equation of motion using the Rung-Kutta method is presented in this paper. And we will show an effect of the swing of the crane in this research.

In this study, we present a mobile robot for ultrasonic scanning of weldment. magnetic Caterpillar mechanism is selected in order to travel on the inclined surface and vertical wall. A motion control board and motor driver are developed to control four DC-servo motors. A virtual device driver is also developed for the purpose of communicating between the control board and a host PC with Dual 'port ram. To provide the mobile robot with stable and accurate movement, PID control algorithm is applied to the mobile robot control. And a vision system for detecting the weld-line are developed with laser slit beam as a light source. In the experiments, movement of the mobile robot is tested inclined on a surface and a vertical wall.

Event-driven communication protocols such as CAN(Controller Area Network) have inherent packet delays due to the contention process for the use of network medium. These delays are stochastic in nature because most packets arrive at random time instants. The stochastic property of the delay adversely influences the control system's performance in terms of stability, responsiveness and steady-state error. Another problem for safety-critical application such as brake-by-wire systems is the reliability of the communication modules that can fail abruptly. This paper deals with two methods to overcome the above problems : (i) scheduling method that can maintain packet delays under some acceptable level, and (ii) redundancy management of communication modules that prescribes dual-redundancy modules' behavior when one of them fails.

This paper has been demonstrated to be essential to successful telemanipulator control when the communication delay between master arms in the operator control station and telemanipulators in the remote site. This paper includes the human dynamics to generate a control command, the monitoring force feedback in order to robust under short time delays and the controller not to requre the derivative of interaction forces. Simulation results suggest that, the proposed control system should be superior to conventional systems in terms of performance and robustness under short time delays.

Air hoist system has been using in the industry. In gradually, the system of function was developing, but system was not enough compensation for leakage. In this paper, developed the anti-leakage system with stability and convenience of operate.

The general dicing process cuts a semiconductor wafer to lengthwise and crosswise direction by using a rotating circular diamond blade. But inferior goods are made under the influence of several parameters in dicing such as blade, wafer, cutting water and cutting condition. Moreover we can not applicable this dicing method to GaN wafer, because the GaN wafer is harder than the other wafer as GaAs. In order to overcome this problem, a new dicing process is necessary. This paper describes a new machine using scriber, breaker, and precision servo mechanism in order to dice an semiconductor wafer.

In the first step of the LIGA process a resist layer, typically PMMA(polymethylmethacrylate), is pattered by deep X-ray lithography. Then the exposed parts are dissolved by an organic developer. To describe the developer. To describe the development course the parameters influencing the development process was investigated. The developed depth is proportional to the square root of the development time which suggests that the development rate increases with increasing dose value and temperature. So the development course can be described by a phenomenological equation.

Micro machining technology has been studied to fabricate small size and high accuracy milli-structure products. To perfectly overcome the conventional mechanical machining methods, the chemical mechanical micro machining(C3M) process was developed. The mechanism of C3M process is that chemical solution etches the material and results in the generation of the chemical reacted layer, and the mechanical micro tool subsequently removes the layer. From the fundamental experiments, the C3M process has been founded to have the advantages of lower machining resistance, tool wear, and higher surface quality and form accuracy than conventional methods. This study focuses on the micro grooving of both the metallic material(SKDII, A1) and hard brittle silicon oxide.

The coordinated mechanism of terrestrial vertebrates enables them to maneuver over all of the terrain conditions since they have a distinct ability to adapt to varying conditions. Their locomotions remain infinitely more advanced and elegant than that of present-day existing mechanical walking robots. However, the principles of existing walking robots are based more on technical rather than on biological concepts, yielding unstable locomotion with low speed. In order to apply these advanced biological phenomena to the mechanical design of 4-legged walking robot, modeling methods are introduced and mathematical equations are also introduced.

Microlens made by laser radiation method have advantages in the easiness of their fabrication. The process is based on the projection of a chromium-on-quartz reticle on to the Polymer using a pulsed 248nm KrF excimer laser. Fabrication process is a fluence-dependent rate and density. The lens shape is defined by a rotationally symmetric sluence distribution with smooth radial variation in the image plane of the reticle. A typical lens of 50㎛ diameter was fabricated by irradiating 2000 laser pulses within 40 seconds. The experimental results show microlens fabrication by UV laser is possible and well worth studying further.

Rapid prototyping is one of the most important technology for 21th century industry. To overcome the limitation of the material and function, Functional Prototype Development(FPD) concept is newly proposed. Wide function is necessary such as mechanical, optical, chemical and electrical property in order to solve broad requirements of the industry. The process of FPD has more than two conventional processes based on fusion technology and the FPD system is integrated with the interdisciplinary, interfacing and intelligent concepts. This paper shows some representative achievements such as optic coloring prototypes, electric multi layer printed circuit broad(MLB) and MEMS using electrostrictive polymer. Finally, we confirmed that FPD has a great possibility which can be applied in broad industry and will be a powerful tool in near future.

Rapid Prototyping (RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of parts due to layer-by-layer stacking, low build speed caused by line-by-line solidification to build one layer, and additional post processing to improve surface roughness, so it is required very high cost to introduce and to maintain RP apparatus. The objective of this study is to develop and design a new RP process, Variable Lamination Manufacturing using expandable polystyrene foam sheet as part material (VLM-S), which can make up for the disadvantage of existing techniques, and to develop an apparatus to implement the process. In order to examine the possibility of practical utilization of the proposed VLM-S process for prototyping of a general three-dimensional shape, an auto-shift lever knob and a pyramid shape were fabricated.

Rapid Prototyping(RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of parts due to layer-by-layer stackin, low build speed caused by line-by-line solidification to build one layer, and additional post processing to improve surface roughness, so it is required very high cost to introduce and to maintain RP apparatus. The objective of this study is to develop software for automatic generation of unit shape part (USP) for a new RP process, Variable Lamination Manufacturing using linear hotwire cutting technique and expandable polystyrene foam sheet as part material (VLM-S). In order to examine the applicability of the developed software to VLM-S, USP's of general three-dimensional shapes, such as an auto-shift lever knob and a pyramid shape were generated.

In order to reduce lean-time and cost, recently the technology of Rapid Prototyping and Manufacturing(PR/M) has been used widely. So various RP/M methods have been developed and these systems commercialized several years ago. The machining process is one of these methods. It also offers advantages such as precision and versatility. But there are some considerations during machining. The most important problem among them is the fixturing. So we have to overcome the limitation because the fixturing time is depend on the complexity of geometry to be machined. In this paper, we have developed the fixturing technique using filling process that can be widely useful for rapid products within a short time. So we have carried out some kinds of rapid products such as plastic knob and metal fan using our fixturing process. In fixturing step, the filling material might chosen a resin or a alloy according to wether the work material is plastic or metal respectively. Also we developed the set-up equipment attachable on the table of the milling machine that provided practicable quality during a series of machining operations, named by two step milling process.

Coiling processes of filaments need precise work and standardization. It is important to maintain equal pitch of filaments. Uniform pitch of filaments is one of the dominant elements of life time and efficiency of bulbs. First coiling process of filament wires is modeled by nonlinear contact problem between filaments and mandrel. Analysis of coiling process using finite element method is conducted to consider manufacturing parameters and pitch distance is calculated under the given conditions. Also image detecting system is developed to inspect uniformity of pitch. This system will be used to inspect quality of filaments during coiling processes.

Magnetorheological Finishing(MRF) is a newly developed and recently commercialized for finishing optical components. The magnetorheological fluid consists of a water based suspension of carbonyl iron, nonmagnetic polishing abrasives, and small amounts of stabilizer. Theoretical analysis of MRF, based on Bingham lubrication theory, is illustrated and a correlation between surface shear stress on the workpiece and material removal is obtained.

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, the finishing process of a non-ferromagnetic pipe by a static magnetic field method is introduced and its finishing characteristics is discussed with effective factors by various experiments. From these experimental results, it is found that the proper suppling quantity of magnetic abrasives per diameter of pipe is important, and the inner surface roughness of pipe is not changed much after certain critical finishing time. As a result of this investigation the 3.2$\mu$m Rmax in inner surface roughness of stainless steel pipe is improved to 0.7$\mu$m Rmax after 6 minutes finishing.

For the development of a ultra-precision CMC polishing system including on-machine measurement system, we study a corrective polishing algorithm. We calculated unit removal profiles for various polishing tools and polishing tool positions. Using these results we simulate the corrective polishing process based on dwell time control. We calculate dwell time distributions and residual error of the polishing simulation method and the FFT calculation method. We got good dwell time distributions and small residual when we used the FFT calculation method. This results will be used for the optimization of corrective polishing process.

Ultra-abrasives such as diamond and CBN have used to maintain accuracy and form deviation for superalloy etc. This study contains the dry cylindrical grinding of metals with Vitrified-bond CBN wheel. For various conditions of grinding speed, workpiece speed, grinding depth and feed speed of table, the grinding resistance, the surface roughness, and the material removal are measured and discussed. The results are as follows.

The environmental problems by using coolant demanded the new cooling methods. As one of them the studies on the dry grinding with compressed cold air have been done. The cooling method using compressed cold air was effdve thmugh going down the temperature of compressed air supplied below $-25^{\circ}C$ and inneasing the amount of mmpresd cold air, but had not enough cooling effect due to the low performance of lubrication. Therefore, the cooling methods using MQL(Minimum Quantity Lubrication) or mist newly were suggested. These two methods can satisfy both cooling effect and lubrication with only small amount of coolant, also has the benefit in the point of decreasing the envimnmental pollution. This paper focused on analyzing the grindmg characteristics of the cooling method using mid. The generated heat and grinding force of the cooling method using mist were compared with them of coolant and compressed cold air. And them grinding test according to the temperature of compressed cold air, mist spray amount and mist supply direction were done.

This paper presents a new method of tool path optimization. A NC verification model based Z-map was utilized to obtain chip load in feed per tooth. This developed software can regenerate a NC program from cutting condition and the NC program that was generated in CAM. The regenerated NC program has not only all same data of the ex-NC program but also the new feed rates in every block. The new NC data can reduce the cutting time and manufacture precision dies with the same chip load in feed per tooth. This method can also prevent tool chipping and make constant tool wear. This paper considered the effects of acceleration and deceleration in feed rate change.

The factors which can improve tool life in machining are consisted of tool geometries, tool materials, coating methods. cutting environments, cutting conditions and so on. Cutting speed in cutting conditions is one of the important factors which can directly influence on the tool life. This paper deals the machinability which is concerned about the cutting direction and the tilt angle of fret form surface in hot die steel(STD I I). The NC datum were analysrd and the effective tool diameters were calculated according to the change of tilt angle the program which can continue the cutting speed with the change of spindle revolution is developed.

Burr makes trobles on manufacturing process due to deburring cost, quality of products and productivity. This paper described the results of experimental study on the influence of the cutting parameters on the formation of exit burrs in face milling. The cutting parameters were investigated changing exit angle, rake nagle , lead angle in tool geometry as well as feed per tooth. Also we carried out experimets on several materials. Using the result of experimental study, burr types are classified according to appearance and formation mechanism in exit burr and we are considered the burr formation in each type of burr.

This paper has two purposes. One is to investigate the effect of the helix angle of endmilling cutter on the cutting haracteristics of inconel 718 in down endmilling. To this end a newly developed cutting force model in down end milling process is presented. Using this cutting force components of 4-tooth endmills with various helix angles have been predicted. Predicted values of cutting force components are well coincide with the measured ones. The other is to compare the down endmilling characteristics of lnconel 718 with those of the up milling previously presented. In up endmilling as the helix angle becomes larger the radial and tangential components of the specific cutting force ($K_1 and K_r$) decrease. While in down milling $K_1 and K_r$ become smaller as the helix angle decrease.

The low density, sustained high temperature strength and excellent resistivity to acid materials have made them strong candidate materials for future aerospace or medical applications. Nowadays their usage has already been broaden to everyday's commercial applications such as golf club heads, finger rings and many decorative items, Anticipating the general use of this material and development of the titanium alloys in domestic furnaces, the review and the study of the machining parameters for those alloys are deemed necessary. The present studies are concentrated to the machining parameters of the Ti-6Al-4V alloys due to their dominant position in the production of titanium alloys.

Burr formed in drilling are classified into three types. no burr, burrs with cap, teared burr. To control burr size in drilling. the second type burrs with cap are to be formed because it is small and uniform. It is necessary to understand the mechanism of cap formation to derive the burr formation into second type burr with cap. In several materials, second type burrs are formed in drilling by changing cutting conditions. It is observed that cap is formed as a result of the plastic deformation along the outside of exit hole. According to the tension behavior of the material in concentrated region between hole and drill outside edge, the geometry of burr with cap is determined.

This paper describes the machining characteristics of the sintered carbide and die steel by electric discharge drilling with various tubular electrodes. Electrical discharge machining(EDM) removes material from the workpiece by a series of electrical sparks that cause localized temperatures high enough to melt or vaporise the metal in the vicinity of the charge. In the experiment, four types of electrode which have different diameter are used with the application of continuous direct current and axial electrode feed. The controlled factors include the dimension of the electrode. In drilling by EDM, the dielectric flushed down the interior of the rotating tube electrode, in order to facilitate the removal of machining debris from the hole.

The purpose of this study is an evaluation of end mills to develop appropriate tools for the high speed machining. First of all, several flat end mills which are produced by different makers are selected to analyze the performances of the tools. Experimental works are also executed to measure cutting force, tool wear and surface roughness for different cutting conditions. And then the results are compared and analyzed for developing optimal cutting tool in the high speed condition. Especially, analysis about tool wear is introduced in this research.

To improve the accuracy of products and improve the product quality, we need to enhance the machining accuracy of the machine tools. To this point of view, measurement and inspection of finished part as well as error analysis of machine tools has been studied for last several decades. OMM(On the Machine Measurement) has been issued to alternate with CMM, pointing out disadvantages of high expenses and lots of setting time in CMM. In this paper, we study 1) the spherical surface manufacturing by volumetric error compensation of machine tool, 2) the system development of OMM without detaching work piece from a bed of machine tool after working. 3) the generation of the finished part profile by On the machine measurement. Furthermore, the output of OMM is compared with that of CMM, and verified the feasibility of the measurement system.

The purpose of this paper is to investigate the influences on mechanical properties of motor pistons manufactured by casting, conventional forging and powder forging, using the comparison of characteristics like microstructure, hardness, tensile strength, and elongation. To form conventional forging piston, the experiment of visioplasticity was performed. As the model material, plasticine was used. To form powder forging piston, the shape of piston was simplified as simple cup shape. Material properties like workability, density variation before and after forging, and strain loci of material during forging were investigated. Powder forging and conventional forging technologies were effective to gain dense microstructure. In powder forging, distribution of such dense microstructuer was uniform. For hardness, pistons from powder forging and conventional forging technologies were much better than that from casting. For tensile strength and elongation, powder forging and conventional forging technologies were also advantageous.

In this paper backward extrusion process with lower die rotation was studied to improve the conventional backward extrusion problems ; requirement of large forming machine, the difficulty to selecting of die material caused by high surface pressure, high cost of forming machine caused by improvement of noise and vibration, and etc. In this experiment, model material, plasticine, was used of specimen. The result values of torsional and conventional backward extrusions were analyzed and compared. FE-simulation is used for analysis with DEFPRM-3D. These results show that the torsional backward extrusion is very useful process because this process can obtain the homogeneous deformation, low forming load. Decreasing forming load improves die life and makes it possible to use press of relatively low capacity. Also this process can reduce corner cavity, improve the initial cast-structure, owing to the high deformation and uniform starin distribution.

It is well-known that Electro-rheological(ER) fluid is a material(suspension) which shows the dramatic change of rheological properties under an electric field. Using these properties, the concept that variable apparent viscosity of ER fluid could be applicable to the polishing for micro parts was introduced. It was investigated that how it works for polishing and how it affects ER effect when abrasives were mixed with an ER fluid. Therefore a few structures for polishing using ER fluid was suggested and evaluated by means of experiments. In this paper, fundamental mechanism and experimental results are described.

This paper presents the experimental results of relationship between the machinability and environmental consciousness due to cutting fluid atomization in machining process. Even though cutting fluid improves the machined part quality through the cooling and lubracating effects, its environmental impact is also increased according to the cutting fluid usage. Cutting tool wear is one of criterion for deciding the machinability. A few turning operations were performed to know the qualitative effectiveness of cutting fluid to tool wear improvement. This research can be used as a basis for environmental impact analysis on the shop floor. It can be also facilitate the optimization of cutting fluid usage in achieving a balanced consideration of productivity and environmental consciousness.

This paper presents the characteristics of cutting fluid atomization due to its application method. In this study three different application methods; nozzle, jet, mist type is adopted for evaluating the cutting fluid's effect in terms of machinability and environmental consciousness. Cutting fluids are widely used to cool and lubricate the cutting zone in machining process. Cutting fluids mist via atomization in spin-off process can be affected to health risk. To satisfy the increasing concern of health and environment problem and keep the machinability or productivity it is necessary to establish the resonable strategy of cutting fluid usage and optimal control. Tool wear and cutting fluid diffusion rate in the air were measured as machinability index and environmental index in a few turing operation. Through this basic approach it can be also provide the optimization of cutting process and improvement of machine tool design in achieving environmentally conscious machining.

The object of this paper is to evaluate the surface roughness using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. $L_9{3^4}$ orthogonal array method, one of fractional factorial design has been used to study effects of main cutting parameters such as cutting speed, feed rate and depth of cut, on the surface roughness. And the analysis of variance (ANOVA)-test has been used to check the significance of cutting parameters. Using the result of ANOVA-test, the experimental equation of surface roughness, which consists of only significant cutting parameter - feed rate, has been developed. The coefficient of determination of this equation is 0.962.

To improve quality of the ground surface, we have to consider a number of parameters. But it is difficult to make experiment with many parameters. Most of all experiments try to search optimal grinding condition with conservative factors such as feed rate, depth of cut, wheel rotating speed, etc. But This paper attempts to view the significance of some different factors effecting on the surface roughness by introducing helical scan grinding method and material removal rate. The design of experiment is used to find the optimal grinding condition which minimizes the surface roughness value bout optical glass material. To analyze experimental results, ANOVA(ANalysis of VAriation) is used. Discussion on the result about helical scan grinding is also given.

This investigation reports the grinding characteristics of titanium alloy(Ti-6Al-4V). Grinding experiments were performed at various grinding conditions and the grinding forces and specific grinding energies were measured to investigate the grindability of titanium alloy with the three different wheels including Diamond, Green carbide and Alumina. To investigate the grinding characteristics of titanium alloy grinding force, force-ratio, specific grinding energy and grinding -ratio, were measured. Surface roughness was also measured with tracer and the ground surfaces were observed with SEM. Force-ratio of grinding of titanium alloy was very lower than that of grinding of SKD-11. Specific grinding energy are almost five times larger and rougher surface was obtained in titanium grinding.

In the previous report1), the grinding characteristics of quartz were investigated. In this paper, the grinding mechanisms of brittle materials including ceramics and quartz are modeled and a new parameter SDR(Surface roughness Direction Ratio) is proposed to characterize the grinding mechanisms of such materials. A set of experiments were performed to verify the effectiveness of the suggested parameter. The experimental results indicate that the plastic deformation is the dominant material removal mode at the grinding conditions which show the higher value of SDR. In the case of quartz, the material was removed by brittle fracture in a lower value of SDR and by plastic deformation in a higher value of it. SDR is not affected by wheel mesh size when brittle fracture occured. But in the plastic deformation case, SDR value increases with wheel mesh size.

Temperature generated in the workpiece during grinding process can cause thermal damages. Therefore it is important to understand surface temperature generated during grinding process. In this paper, a theoretical and experimental investigation were performed for the grinding temperature. Grinding experiments were performed in machining center using vitrified bonded CBN cup-type wheel. The surface temperature was measured using thermocouple and calculated through a model of the partition of energy between wheel and workpiece. The residual stress and hardness of ground surface were measured. The experimental results indicate that the surface temperature was in good agreement with theoretical ones. Residual stress and hardness of ground surface were more affected by the change of table speed than the depth of cut.

In the present industry, there is not only the cutting of iron metal, but also the cutting of alloy aluminum, brass and plastic to wood(Paulownia). A variety of material is used and these industry is made need of the cutting material but lots of experiments processing is not enough at the moment. At this point, our team processed the basic experiment about influencing of Feedrate and Backrake angle of bite concerned to manufacture in the turning of non-iron metal. Generally speaking, we recognized that there was occurrence of increase of Surface Roughness with increasing of cutting angle in the non-iron metal, but in the cutting of wood we knew, there was special change with change of cutting angle

Drilling is one of the most important operations in machining industry and usually the most efficient and economical method of cutting a hole in metal. From automobile parts to aircraft components, almost every manufactured product requires that holes are to be drilled for the purpose of assembly, creation of fluid passages, and so on. It is therefore desirable to monitor drill wear and hole quality changes during the hole drilling process. One important aspect in controlling the drilling process is drill wear status monitoring. With the monitoring, we may decide on optimal timing for tool change. The necessity of the detection of tool wear, fracture and the abnormal tool state has been emphasized in the machining process. Accordingly, this paper deals with the cutting characteristics of the hot-rolled high strength steels using common HSS drill. The performance variables include drill wear data obtained from drilling experiments conducted on the workpiece. The results are obtained from monitoring of the cutting force and Acoustic Emission (AE) signals, and from the detection of the abnormal tool state with the computer vision system.

In this study, tap wear was analyzed not only to predict the tap life time but also to propose an improved tap design. Because rake angle and thread relief of tap are the significant factors in geometry of tap, these two factors were picked as the experiment variables. The experiment was conducted with six types of tap which have 6$^{\circ}$ , 8$^{\circ}$ and 12$^{\circ}$ of rake angles with 0,08mm and 0.14 mm of thread relief. From the measured cutting force, it could be known that cutting torque was low at the large the rake thread relief and tool life was long as rake angle became large. Eventually, tool life is longest when rake angle is 12$^{\circ}$ and the with 0.08mm thread relief. Aand the width of crater wear and that of flank wear were measured when a tapping torque was 20 [$kg_f$-mm] . Most of the measured values were above the width of tool wear[$V_B$=O.O3m], which means that tool life is over.

It is known that Si3N4 ceramic insert has less hardness than Al2O3 ceramic insert. But Si3N4 ceramic insert has not only high toughness and strength but also low thermal expansion coefficient, which makes it has longer tool life under thermal stress condition. In this study, commercial Si3N4 ceramic insert and home-made SiC-Si3N4 ceramic insert which has different sintering time and chemical composition is tested under various cutting conditions. The experimental result is compared in terms of tool life and cutting force. Generally, As the cutting speed and the feed rate increased, the cutting force and the flank wear increased too. The performance of SiC-Si3N4 ceramic insert shows the possibility to be a new ceramic tool.

As the manufacturing processes of automotive engine piston, gravity die-casting, squeeze casting, hot forging and powder forging process are generally used for the various specifications. As the semi-solid forming(SSF) is compared with conventional casting such as gravity die-casting and squeeze casting for the characteristics of its process, the product without inner defects such as gas porosity and segregation can be obtained and its microstructure is globular grain. In SSF process, the materials are heated up to the temperature between the solvus and liquidus line at which the materials exists in the form of liquid-solid mixture. In this time, Discussion is given about reheating process of row material and results are presented regarding accurate temperature and process variables controlling for right solid fractions.

To improve dimension accuracy and make very small parts are one of the major purpose on the electrochemical micromachining. This paper introduce a small machine tool by using the point electrode. That has a data acquisition system for gathering applied electric condition between the gap. Point electrode on this system was made by this method as well. It was found that variable phenomena occurred through the acquired V-I curve on the process.

In this research we investigate geometric issues involved while using a particular rapid prototyping system, called Stereolithography(SLA). SLA create prototypes layer by layer, each layer being formed by scanning a laser beam across the x, y surface of a vat of liquid monomer mix. The performance of SLA is influenced by orientation and layer thickness of designed fabrication. The number of layer and the area needed support is influenced by the orientation and layer thickness of designed fabrication. The step influence and volume error is influenced by slice thickness. We minimize the support are, the number of layer and cusp height. These variables of fabrication is minimized using genetic algorithm. The time for genetic algorithm is as little as we can accept. So we calculate support area and cusp height simply.

Application of ceramics, carbide, ferrite has grown considerably due to significant improvement in their mechanical properties such as light weight, chemical stability , super wear resistance and electronical. Despite these character, the me of advanced material has not increased because of poor machinability. The method of using of metal bond wheel was proposed. But it is difficult that metal bond wheel can be dressed. Recently, the technology of in-process electrolytic dressing is developed to solve this problem. This method need wheel for electrolytic dressing, power supply and electrolyte. But development of wheel for electrolytic dressing is the most need. The aim of this study is development of wheel for electrolytic and appraisement of CIB-diamond lapping wheel

Micro-machining, one of the non-traditional machining techniques, can achieve a wanted shape of the surface using metal dissolution with electrochemical reaction and can be applied to the metal such as high tension, heat resistance and hardened steel. The workpiece dissolves when it is positioned close to the tool electrode in electrolyte and the current is applied. Traditional machining has been used in the industries such as cutting, deburring, drilling and shaping. The aim of this work is to develop Micro-machining techniques for micro shape by establishing appropriate machining parameters of micro-machining

As mechanical components require size minimization and high precision, micro die machining technology has been developed in many fields. to machine a micro die by EDM, sometimes, a polygonal electrode is use. Machining corners by MEDM shows special characteristics. Physically, electrons are concentrated in sharp region and a high potential level is established in this region. Also, the electrode can't be rotated when machining a polygonal cavity, and machined debris can not drawn off easily. Discharge concentration in corners and 2nd discharge by machined debris result in distortion of corner shape. This phenomena can be improved by shaking the electrode. This method is also shown to be effective in improving surface roughness by circulation of machining fluid resulting from movement of the electrode.

As the track density of hard disk drives increases, there is a need for more precise actuation of the head. This can be accomplished by using a high band width micro-actuator. In this work, the flying characteristics of sliders with micro-actuators are investigated with the aim to optimize the head/disk interface performance of such sliders. Contact-start-stop, sweep, and flying height tests are performed and analyzed. The results show that the MEMS based micro-actuator mounted on a slider possess acceptable flying characteristics.

In this report experimental ultrasonic machine system has been fabricated and experimental machining has been performed using glass as a workpiece material. As grit size increases, material removal rate(MRR) was observed to be increased at decreased applied tool pressure on the workpiece, however at the higher applied pressure above $2-4\;kg/cm^2$ for smaller grit size, the MRR was not increased. Also better surface roughness was obtained for smaller grit size. Microchipping was observed from the microscopic examination and the pattern is similar to the iso-stress field where cracking is considered to be initiated near the surface.

This paper presents a laser cutting of 2D image. 2D image in pixel graphic format is converted into vector graphic image by image processing. Bitmap graphics are made easily, but can not being used in application works for geometry transition. The Sobel's Edge detection method is used to find boundary points on 2D image. The points are fitted into curves with sampling and filtering. Sampling can provide efficient computation and filtering reconstuct features in image. The NC code is generated on MURBS curve of the points. Also, the offset of contour and cutting conditions are considered.

Single point diamond turning technique for optical crystals is reported in this paper. The main factors influencing the machined surface quality are discovered and regularities of machining process are drawn. Optical crystals have found more and more important applications in the field of modern optics. Optical crystals are mostly brittle materials of poor machinability. The traditional machining method is polishing which has many shortcomings such as low production efficiency, poor ability to be automatically controlled and edge effect of the workpiece. The purpose of our research is to find the optimum machining conditions for ductile cutting of optical crystals and apply the SPDT technique to the manufacturing of ultra precision optical components of brittle material.

Selective laser sintering(SLS) is a solid freeform fabrication process whereby a part is built layerwise by scanning a powder bed. The properties of metal powder are dependent on the heat, it is not easy to do the exact error compensation with analysis and estimation by modeling. This paper suggests that the error is compensated by experimental method and then the accuracy of shape is enhanced by revising of STL file. Also bonding force is measured by an experiment with change of process path.

The purpose of this paper is to investigate the effect of the helix angle of endmilling cutter on the cutting characteristics of inconel 718 in up endmilling. To this end cutters with helix angle of $20^\circ$, $30^\circ$, $40^\circ$ and $50^\circ$ degree have been prepared. And a modified cutting force model in up end milling process is presented. Using this cutting force components of 4-tooth endmills with various helix angles have been predicted. Predicted values of cutting force components are well coincide with the measured ones. As helix angle increases overlapping effects of the active cutting edges increase.

This paper presents a new cutting method, i.e. diamond cutting, aided by electrolysis, in order to cut ferrous materials with diamond tools. Diamond cutting is widely applied in manufacturing ultraprecision parts such as magnetic disk, polygon mirror, spherical/non-spherical mirror and copier drum, etc. because of the diamond tool edge sharpness. In general, however, diamond cutting cannot be applied to cutting steels, because diamond tools wear excessively in cutting iron based materials like steel due to their high chemical interaction with iron in high temperature. In order to suppress the diffusion of carbon from the diamond tool and to reduce increase of cutting force due to size effect, we attempt to change chemically the compositions of iron based materials using electrolysis in a limited part which will be soon cut. Through experiments under several micro-machining and electrolysis conditions, cutting using electrolysis, compared to conventional cutting, was found to result in a great decrease of the cutting force, a better surface and much less wear tool.

In this paper, the electro-chemical-machining characteristics of Ni-Ti Shape Memory Alloy(SMA) was investigated. From the experimental results, the optimal electro chemical machining conditions for satisfying the machining quality(fine surface & high recovery stress)might be confirmed. And it was concluded that optical electro chemical condition for Ni-Ti SMA could be obtained at approximately 100% current efficiency and high frequency pulse current.

A new method compounding the electrolytic machining with ball end milling process to improve machined surface toughness was examined. From this study, it was confirmed that much smaller cutting force and finer surface roughness can be obtained in a certain condition of ball end milling and electrolytic machining conditions.

Abrasive jet machining(AJM) process is similar to the sand blasting, and effectively removes hard and brittle materials. AJM has applied to rough working such as deburring and rough finishing. As the needs for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro AJM was developed, and became the inevitable technique to micromachining. This paper describes the performance of the micro AJM in micro groove cutting of glass. Diameter of hole and width of line in this groove cutting is 80${\mu}{\textrm}{m}$. Experimental results showed good performance in micro groove cutting in glass, but the size of machined groove was increased about 2~4${\mu}{\textrm}{m}$. therefore, this micro AJM could be effectively applied to the micro machining of semiconductor, electronic devices and LCD parts.

In this paper, shortening of product life cycle and wide disposal of consumer product have given rise to many environmental problems, it needs to propose module design principle for saving of disassembly cost and reusing of used part and subassembly. To analyze characteristics of module for recycling, materials and function of part and subassembly must be classified. In disassembly process, a unit operation can be grasped for disassembly function, worker, tool and sorting process. As a result of applying module design principle, simpler structure and reduced structural interference can be realized for product structure. For disassembly, simpler disassembly and quicker disassembly can be obtained for recycling.

Environmental factors have become important in manufacturing planning due to governmental regulations and a growing preference for "green" products. However, planning decisions must also consider traditional dimensions such as production rate and quality. In this study, technology related to basic dicision method of environmentally conscious machining considered economic view was dealed. And experiments of dry type machining excluded coolant and semi-dry type machining using minimum coolant were established for the comparison of conventional machining ouputs.ng ouputs.

This paper describes a Life Cycle Engineering approach which is able to optimize a product under technical, ecological and economical requirements. The methodology of Life Cycle Engineering comes with a holistic approach for the analysis of processes, products, systems or services. The Life Cycle Engineering approach is combining environmental and economical parameters and using the technical requirements for setting the baseline for the studies. This paper also describes the approach method for ？ㄴ composed in large numbers sub-parts.

The world faces a legacy of serious environmental problems such as exhaustion of natural resources and lack of landfill sites. To address these problems, recycling of materials and products has been proposed, but at present, it is realized only within a few fields. This is because most industrial products consist of various components made of different materials and their recycling are based on the assumption that they can be separated and classified easily, the actual situation however cannot satisfy this assumption. The issue in recycling the components and wastes of used cars, in turn, gives rise to emphasis on the disassembly process. For the efficient disassembly, the component materials and their easy separation as well as the recyclability must be taken into account as early as in the design process. It should be developed an almost perfect design catalogue with existing technologies by analyzing design characteristics, manufacturing, assembly and disassembly processes for major parts and components of automobiles in terms of existing and newly proposed recycling technologies. Also it is essential to provide more technical know-how and application methods that may be helpful to utilize different components and component groups.

In a high speed spindle system, it is very important to monitor the operation of the spindle to prevent catastrophic damage to the system. Widely used sensors for monitoring are eddy-current and capacitive types. These sensors provide high accuracy of monitoring, but their steep prices lead to expensive high speed spindle systems. The main goal of our research is to develop technology for producing high speed spindle system utilizing magnetic bearings. As active magnetic bearings require position sensors for feedback control, a noncontact position sensor is being developed as a part of this main goal. Once developed, it will contribute to affordable high speed spindle system. This paper describes the selection process of the sensor types and the design of the driving circuit. We also report the experimental results that characterize the static and dynamic performances of the inductive sensor.

A brushless linear motor is suitable for a high-accuracy servo mechanism. It is also suitable for operation with higher speed and precision. Since it does not involve some sort of mechanical coupling, linear driving force can be applied directly. Basic models including magetomotive force and electromotive forces are introduced and simplified. Both conventional PID and fuzzy controllers are implemented and performance results using those controllers are compared. Along with better simulated performance observed using fuzzy controller, further fabrication is to be included with various empirical results. Several system operational characteristics have been observed. Typical nonlinearities as friction, cogging and torque or thrust ripple that might deteriorate system performance would be tackled using presumably effective method such as neural network based learning controller.

In this paper, the case studies of reducing rotational errors is theoretically done for a grinding spindle with an active magnetic bearing system. The rotational errors acting on the magnetic bearing spindle are due to mass unbalance of rotor, runout, grinding excitation and unmodeled nonlinear dynamics of electromagnets. For the most case, the electrical runout of sensor target is big even in well finished surface, this runout can cause a rotation error amplified by feedback control system. The adaptiveed forward method based on LMS algorithm is discussed to compensate this kind of runout effects, and investigated its effectiveness by numerical simulation and experimental analysis. The electrical runout form the rear sensor target of grind spindle is about 70$\mu\textrm{m}$ with harmonic frequencies. The rotor orbit size in rear bearing is reduced about to 5$\mu\textrm{m}$ due to 1X and 2X rejection by feedforward control.

The goal of this study is to develop a linear DC motor with high thrust, speed and stiffness for machine tool. In the first phase of this study, We has made a pilot model and measuring system. Using the measuring system, We could finished the performance test of the pilot model, which continuous thrust is 1, 391N. Experimental values agree with the theoretical results well. In a certain sense, We are expecting the realization of linear motor with continuous thrust of 6, 000 to 7, 000N next time.

In this study, a multi-step optimization technique combined with a simple genetic algorithm is introduced in order to minimize the static compliance, the dynamic compliance, and the weight of a high speed machining center simultaneously. Dimensional thicknesses of the eight structural members on the static force loop are adopted as design variables. The first optimization step is a static design optimization, in which the static compliance and the weight are minimized under some dimensional and safety constraints. The second step is a dynamic design optimization, where the dynamic compliance and the weight are minimized under the same constraints. After optimization, the weight of the moving body only was reduced to 57.75% and the weight of the whole machining center was reduced to 46.2% of the initial design respectively. Both static and dynamic compliances of the optimum design are also in the feasible range even though they were slightly increased than before.

In this study, a failure mode analysis of CNC machining center is described. At first, the system is classified through subsystems into components using part lists and drawings. The components failure rate and failure mode analysis are performed to identify the weak components of a machining center with reliability database. The failure probabilistic function of mechanical part is analyzed by Weibull distribution. The Kolmogorov-Smirnov test is also used to verify the goodness of fit.

Reliability engineering is regarded as the major and important roll for all industry. And advanced manufacturing systems with high speed and intelligent have been developed for the betterment of machining ability. In this study, we have systemized evaluation of reliability for machinery system. We proposed the reliability assessment and design review method using analyzing critical units of high speed and intelligent machine system. In addition, we have not only designed and developed test bed system for acquiring reliability data, but also have constructing WEB system for suppling reliability which is provided in design phase. From this study, we will expect to guide and introduce the reliability engineering in developing and processing phase of high quality product.

Enhancement of the accuracy of products and productivity are essential to survive in a global industrial competition. This trend requires tighter dimensional tolerance specifications. To actively cope with the rapid change of the workpiece material and cutter geometry, a general method that can predict and analyze the machined surface is needed. Surface generation model for the prediction of the topography of machined surfaces is developed based on cutting force model considering cutter deflection and runout. This paper presents the method that constructs the three-dimensional machined surface error following the movement of a cutter, irrespective of the variations of cutting conditions. In addition, the effects of the cutting forces and the kink shape on the machined surface are extensively investigated.

In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. This paper models of the thermal errors for error analysis and develops on-the-machine measurement system by which the volumetric error are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball artifact, and five gap sensors. In order to analyze the thermal characteristics under several operating conditions, experiments performed with the touch probe unit and five gap sensors on the vertical and horizontal machining centers.