제어로봇시스템학회:학술대회논문집
Institute of Control, Robotics and Systems (ICROS)
- 기타
Domain
- Machinery > Robot/Automated Machinery
1987.10b
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A cotroller is designed and implemented for a 4-axis SCARA type assembly robot. The controller is developed for velocity control and precise position control of the AC servo motor and a robot language SNUL-87 is designed using c-language , which is oriented towards an intelligent robot system.
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In this study, three insertion techniques vibration method, tactile sensor-assisted method and vision assisted method are developed for the insertion of electric contacts into connectors. In order to prove their Performances, a series of experiments were conducted for various shapes of el-ectric contacts. From the experimental results, three insertion methods are compared and their merits are discussed in detail.
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The main work of this paper are the manufacture of six degree of freedom industrial robot control hardware of 16 bit CPU and the development of five motion control software. The work would draw on KIT of Robotics Laboratory whose extensive experience in these areas; in particular the 68000 assembler and Modula-2 languages, and existing robot control systems. We found that this controller is good for the robot controller of PID types. But, for the use of self-tuning algorithms and real time calculations we need 32 bit CPU robot controller such as MC 68020 microprocessor.
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In this paper, a system program is introduced for the effective operation of revolute type robot manipulator. The I system program consists of several modes and specific functions. These modes and functions are flexible and easy to use because the structure is modular and conversational. This program had implemented and verified the efficiency together with a five axes robot.
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A program is developed for generations the dynamic equations for robotic manipulators using the symbolic language muSIMP/MATH. The muSIMP/MATH is a LISP-based computer algebra package, devoted to the manipulation of algebraic expressions including number, variables, functions, and matrix. The muSIMP/MATH can operate on IBM-PC compatibles with MS-DOS. The program is developed, on the e formalism. This is program is applicable to the manipulators of any number of degrees of freedom, maximum six degree of freedom in this program. To control robotic manipulators by using dynamic equation is required a symbolic equations. The generated dynamic equation can be applied directly to the robotic manipulators, for the generated dynamic equation is a reduced form of symbolic expression.
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A Computer Aided Design (CAD) program of robot application engineering has been developed for the efficient examination of HR8000 robot. For the Simulation of robot motion. direct and inverse kinematics of robot manipulator was analyzed and robot motion was visualized. The program could contribute to upgrade accuracy and to minimize the time for the robot application engineering.
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As the conventional manipulators are centralized system, they are considered to have many problems in future because of their wiring and software. For this reason, a rather advanced intelligent manipulator Is not able to realize by using the centralized concept. And this paper describes the manipulator based on autonomous distributed concept to solve the problems.
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An adaptive control scheme has been recognized as an effective approach for a robot manipulator to track a desired trajectory in spite of the presence of nonlinearties and parameter uncertainties in robot dynamic models. In this paper, an adaptive control scheme for a robot manipulator is proposed to design the self-tuning controller which combines the pole placement with the extended linearized perturbation model. And this control scheme has two components: a feadforward control and a feedback compensation control. Based on this, the controller is demonstrated by the simulation about position control of a three-link manipulator with payload and parameter uncertainty.
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현재 사용되고 있는 작업방식은 로봇과 positioner의 상대적인 위치 및 자세설정에 의하여 작업효율 및 성능향상을 꾀할 수 있음에도 불구하고 비효율적인 방법으로 사용하고 있는 실정이다. 이러한 문제점을 해결하기 위한 방법중의 하나로 로보트와 positioner시스템을 하나의 기구학적 모델로 제어하는 방법이 제시된 바 있다. 상기의 연구에서는 로보트와 positioner(이하 R-P 시스템)간의 협조 제어가 여유자유도제어 방법을 이용하여 가능한 것임을 보였다. 그러나 용접작업과 같은 positioner 위에서의 연속경로 작업에 있어서는 작업공간과 특이성(singularity) 등에 관련된 여러 가지 문제점을 안고 있다. 특이성은 외부의 물리적인 제약이나 로보트의 기하학적 구조의 문제로 발생될 수도 있는데 이때 자유도의 손실을 유발하므로 임의의 원하는 방향으로 움직일 수 없게 된다. 이러한 면에서 R-P 시스템의 조작 성능 평가가 중요한 의미를 갖는다. 본 연구에서는 실제 산업현장에서 이용되고 있는 5 자유도를 갖는 수직 다관절형 로보트와 positioner에 대하여 협조 제어 방법을 검토한다. 그리고 작업공간 내의 조작성능평가를 위하여 Jacobian 행렬을 이용한 조작성지수를 위하여 Jacobian 행렬을 이용한 조작성지수를 도입하고 주어진 작업단면에 대한 이들의 분포를 등고선 그래프로 시각화 한다. 또한 조작성지수를 최대화 하는 알고리즘을 R-P 시스템에 적용하고 시뮬레이션을 통하여 그 타당성을 검토한다
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A new control scheme is developed to achieve fast and accurate decoupled tracking for an n-Joint robotic manipulator In the Presence of disturbances and unknown Parameter variations. The control system is designed so that a new type of state trajectories called sliding mode may exist in a phase plane. In order to remove the reaching Phase and high frequency chattering phenomenon which ate the common shortcomings of variable structure control(VSC) scheme, this paper presents the new switching line which is composed of three segments and the continuous control law which is derived from the existence condition of a sliding mode. The Proposed methods in this Paper are applied to a 3-Joint robotic manipulator as a numerical example-The digital simulation results which are compared with those of typical VSC scheme show the validity of accurate tracking capability and robust Performance of the system.
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This paper presents a decentralized adaptive control scheme based on Lyapunov design for robotic manipulators, which make possible the joint independent control without neglecting the coupling between the joint motions. The performance of the presented scheme is compared via computer simulations with the conventional joint independent control scheme.
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In this paper, it is dealt with the dynamic motion equations for a robot arm. Four kinds of the dynamic equations which are the Lagrange-Euler equations, the Recursive L-E equations, the Newton-Euler equations and the improved N-E equation are derived on robot PUMA 600. Finally the algorithms on these equations are programmed using PASCAL. and are compared with each other. As the results, it is found that the improved N-E equations has the most fastest execution time among the equations and can be used in real time processing.
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In this paper, path planning, modelling, and control of manipulators are described. The path planning deals with specifying how to define the motion of hand along straight line paths in the minimum amount of time. A new model was developed for the manipulator, which is based on the classical equations of motion of a rigid body. A new control algorithm was developed which controls the manipulator in terms of the position and orientation of the hand.
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In this study, a pantograph leg of the four legged walking vehicle is analysed with regard to mechanical energy consumption. Energy efficiency of the vehicle is estimated in terms of specific resistance varying body height, stride length and walking speed. The interaction between specific resistance and the parameters is investigated.
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In this paper the continuous static stable gait, kinematics and the basic control algorithm of the quadruped walking robot have been discussed. The control method described in this paper will be extended for the walking robot to walk on an uneven terrain.
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This paper presents a control algorithm of servo controller for a quadruped walking robot as well as its characteristics and requirements. The control algorithm for propelling and terrain adaptive motion is described. The servo controller is being developed as a sub-project of the national project - "Development of a quadruped walking robot ". And then, this paper focuses on an overview of the current state and future works of this sub-project.b-project.
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This paper describes the mobile robot system to recognize the guidance tape, and presents the locomotion algorithm. It is composed of image processing unit, A/ID converter and camera. This system converts video image to binary image by setting an optimal threshold and obtains the parameters to move the robot. The mobile robot moves according to the programmed route in memory. But after recognized the obstacle on the locomotion route, this system constructs the new route and the robot moves following the new route.
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A vision algorithm is presented for the separation of near objects from distant objects. In the algorithm, a difference field of a stereo pair of images is computed to obtain the range information and the median filter is used for the suppression of distant objects. The objects within a given distance is segmented by thresholding the gray scale cross-section of the median filtered difference field. The experiment is performed in a laboratory setting.
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This paper gives the Sonic Range Finder(SRF) Array which detects the unknown obstacles on the mobile robot's path. This SRF Array gives mobile robot's circumstance information wider, processes and transfers them to the locomotion module to construct the modify path. In this system, 8 pairs of the 40 KHz ultrasonic sensors constitute the SRF Array, including a pair of reference sensors to correct the errors, 4051 analog multiplexer and demultiplexer swtch the sensor with time and 8031-on chip micro computer controls processes the data and communication the others.
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In the way of perception and depth finding of 3-D scene stereo vision is one of the best ways. Matching is important problem of stereo vision. In this paper we develop an algorithm that is adaptable to errors and computation time. And we demonstrate the way of matching.
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This paper shows the robot-vision system which consists of robot, vision system, single board computer and IBM-PC. IBM-PC based system has a great flexibility in expansion for a vision system interfacing. Easy human interfacing and great calculation ability are the benefits of this system. It was carried to interface between each component. The calibration between two coordinate systems is studied. The robot language for robot-vision system was written in "C" language. User also can write job program in "C" language in which the robot and vision related functions reside in the library.side in the library.
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In this paper, a new algorithm is proposed to obtain important corner and real corner points of the simple objects and the visual robot graphics simulation using the results is studied. This is capable of performing as a debugging tool for task programming of a visual robot. And the robot motion is also simulated on a CRT terminal.
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In this thesis, we work on the curve recognition with real time processing and the Robot tracking method on recognized curve. Image information of segment curve is supplied to computer to run to a Robot so that it is a feedback system. Image coordinate frame to world coordinate transformation represents in this paper and curve matching algorithm subscribes by two method, first transformation matching algorithm, second image coordinate matching algorithm. Also Robot running time to computer image processing time relationships finally includes.
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In this paper the observer design problem in bilinear systems is studied using the Walsh functions as approximating set of functions to find a finite series expansion of the state of bilinear system. A classical Liapnove method, to finding a class of observer feedback matrix, is applied to ensure uniform asymptotic stability of the observation error dynamics. An algorithm is derived for observer state eq. via Walsh function. The basic objective is to develop a computational algorithm for the determination of the coefficients in the expansion. This approach technique gives satisfactory result as well provides precise and effective method for the bilinear observer design problem.
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Linear time invariant systems are considered. It is assumed that only partial state variables are observable for feedback control. In this study, a new method is presented for designing a stat e feedback controller. It is based on augmenting the original system by additional integrator and using time delayed feedback of observable variables. Several examples and its computer simulation results are given to show the effectiveness of the proposed method.
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The stability margin of the LQ regulator is investigated in the time domain. it is shown that the same guaranteed gain margin as that of the frequency domain analysis can be obtained with simple assumptions for the continuous time systems. It is also shown that the allowable modelling error bound can be expressed in terms of system matrices and Riccati equation solution. Guaranteed qain. margin and the allowable modelling error bound for the discrete time systems are also obtained by the similar procedures. In this case, through the some examples, the gain margin is shown to be less conservative than the frequency domain analysis result.
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이 논문에서는 매개변수(parameter)들이 시간에 따라 변하는 선형 시변 시스템(linear time-varying system)에서 시스템의 안정도(stability)를 보장할 수 있는 매개변수들의 변동영역(perturbation region of parameters)에 대한 충분조건을 시간영역에서 Lyapunov 방법을 사용하여 구하였다. 그리고 이 충분조건을 만족하는 매개변수 변동영역을 비선형 계획법(nonlinear programing)을 이용하여 구하는 방법을 제시하였다. 시뮬레이션 결과 이 방법으로 지금까지 이루어져 왔던 다른 연구 결과들보다 더 넓고 다양한 매개변수 변동영역을 구할 수 있었다.
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A method for designing a robust tracking controller for linear discrete systems is investigated. Only the observable variables are to be used in the controller synthesis. To insure the robustness, the system is augmented by a compensator at the output side. Then a feedback controller is designed using delayed values of the observable variables for the augmented system. The delay times are chosen to minimize the effect of measurement accuracy and/or noise.
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The problem of process(Sensor) fault management in Observer Based Control System are considered and structures of Fault Tolerant Observer based Control Systems (FMCS) that function well in the face of the faults are proposed. The FTOCSs include detection logic unit and an additional observer driven by residuals of primary observer and estimate estimation errors of primary observer and fault variables. Since the FTOCSs have the ability to detect and accomodate the faults the original control objectives can be accomplished without considerable control performance deterioration even in the faulty environments. Therefore, the Proposed FMCSs can effectively be used for enhancing the functional reliability of the Observer Based Control Systems.
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The input-output relation for nonlinear systems can be explicitly represented by the Voltera functional series and it is characterized by the Volterra Kernels. A block diagram reduction method is introduced to determine the Volterra Kernels for the nonlinear systems represented by nonlinear differential equations. Degree of nonlinearity is defined and analyzed for the analysis of nonlinear systems.
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A new mixed approximation method is proposed for the model reduction of high order linear and time-invariant dynamic systems. This method makes allowance for stability and feature retention simultaneously. After defining dominant frequency range which affects relative stability of systems, a part of denominator is obtained using the energy dispersion method and tests are obtained using dominant frequency response matching method. The proposed method reflects the characteristic of the original system more faithfully and guarantees absolute stability of the reduction model.
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In this paper, the model reduction method of the linear time invariant continuous systems is proposed. The denominator of reduced order model is determined by the eigenvalue selected considering the error of the power series that exists between original system and reduced order system at each time moments. And the numerator of model is founded by the time moment matching method. The method suggested is compared with other various methods in examples.
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An FTCS is developed for the purpose of improving the reliability of a process control system. The proposed FTCS has capabilities of failure detection, back-up control, graphic display, and self-checking. Also the FTCS is combined with the process simulator to experiment in laboratory for the evaluation of performance of operation. The FTCS is applied to Thermal Power Plant .
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The optimal Input design problem for linear system Which have the common parameters in the system and noise transfer functions. Exploiting the assumed Model structure and deriving the information matrix structure in detail, D-optimal open-loop stochastic input can be realized as an ARMA process under the Input or output variance constraints. In spite of the reduced order, It Is necessary to develop an efficient algorithms for the optimation with respect to the .rho..
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In the design of reference model based STC (self-tuning controllers), parameters of the controllers are determined not from the true plant but from the estimated model. In this paper, we suggest a power spectrum estimation method for visualling the sensitivity of the closed loop system without knowing the explicit original plant.
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In this paper, a self-tuning controller design is proposed by using pole-zero placement method and considering a system time delay. To got better tracking for the generalized self-tuning controller, pole placement method for the closed loop system and zero placement method for the error transfer function are Introduced. The proposed method shows better efficiency than pole placement method for minimizing tracking error. Simulation gives good results in tie reference signal tracking.
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When a .epsilon.
$_{1}$ -modification is applied to a plant with unmodeled dynamics and bounded output disturbance, the output error seems to be relatively large. A .epsilon.$_{1}$ -modification with the same switching action as in the switching a modification is proposed to reduce the output proposed adaptive control scheme is to a second-oder plant and it can be asserted that the control objective is satisfied. -
The controller with robustness described in this paper is designed for processes with variable time-delays. This adaptive mechanism includes servo and stabilizing compensators. In the proposed multivariable controller. knowledge of the system time-delay is not required.
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In the paper an multivariable decoupling self-tuning algorithm is proposed for controller design, by specifying the closed-loop behaviour of the system in the form of a reference model, so that the controller parameters can be estimated on-line as the process development. The effectiveness of this algorithm in controlling multivariable systems is demonstrated by simulation example in spite of the usual implementation problems of self-tuning controllers.
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Decentralized model reference adaptive controller is used to control interconnected system. Influences caused by interactions between each subsystem are regarded as unmodeled dynamics or disturbances, thus decentralized adaptive controller is designed using MRAC algorithms which guarantees robustness. To expand the stability regions of over all system and to improve control performances, higher level controller is introduced to adjust the control factors such as filter band, size of deadzone or maximum norm of parameter. Local controllers for each subsystem are realized in real time and higher level controller has an ability of detecting the instability phenomena and adjusts the local controller by analysis of power spectrum or square sum of tracking errors.
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The regulator problem can be considered as some impulsive disturbance rejection one. In this point of view, the rate of decay is one of important factors for regulation and depends on how negative the real parts of the eigenvalues of closed-loop system. The algorithm that the closed-loop system has eigenvalues lying within a vertical. strip is useful for rapid disturbance rejection. This paper presents a design method for a linear quadratic regulator of two-time scale system with eigenvalues in a vertical strip by use of time-scale separation property.
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Design problem of output feedback controllers for discrete large scale systems using simplified model is investigated. It is shown that neglecting fast modes does not generally guarantee the stability of the closed loop system. In this paper, the design procedure is proposed to stabilize the system by minimizing a quadratic cost function for the simplified model and a measure of stability for the neglected fast model.
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This paper presents decentralized discrete-time system which is optimized by hierarchical control for process automation via the extended interaction balance method. This proposed method can control general matrix which input matrix is not block diagonalization. Also, this paper shows convergence condition of proposed method.
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In this paper self tuning control of interconnected systems are dealt in view point of large scale system control. The plant model is given in multiple ARMA process. This process is simplified as independent SISO ARMA process having offset terms. This offset was considered as effects of interconnections. In each decentralized system, self tuning controller with instrumental variable method is adopted. As a result, this algorithm enables the parameter estimation to be unbiased and non-drift. This controller contains a new implicit offset rejection technique. Simulation results considers well with the analysis in case of linear interconnection.
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The continuously variable transmission (C.V.T.) has been introduced for many years, however, the application of C.V.T. system has been used rather restrictively because of the problems such as reliability, durability, efficiency and, controllability. In this paper, some of the research trends about the control algorithms and the system design method involving C.V.T. is introduced. An engine is assumed in operation along the ideal operating line and it is also considered to be controlled independently to the C.V.T. system. The control simulation has been carried out to confirm it and also the operation performance of the system is investigated.
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This paper presents the extended interaction prediction method for large scale discrete-time systems with interconnected state and control. Feedback gain is obtained from decentralized calculation without solving Riccati equation. Hence, Computer storage and calculation time is reduced.
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Microprocessor-based software DDA interpolator is developed and applied to two axis contouring control of X-Y table. Developed assembly program is composed of feedrate, linear and circular DDA interpolation routines. Reference-pulse type of open-loop stepping motor control system in which the micro-computer produces a sequence of reference pulses for each axis of motion is adopted. To test performance of the developed program, X-Y table drive system based on stepping motor and shaft encoder is designed. Contouring error of the system in linear and circular path is within .+-.0.2 mm.
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To improve the surface waviness in the peripheral milling, since the tool deflection is largely affected by cutting force, the feedrate is controlled so that the cutting force measured in the normal direction to the workpiece is constant. A discrete time first order model between the feedrate and the tool deflection is derived for the control. The experimental results show that the surface waviness is greatly improved by the proposed method.
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In this paper, the BTR (Behind the Tape Reader) type communication unit which interfaces the IEBM PC/XT to the FANUC 5M NC controller is developed, making it possible to send NC part program from the memory of IBM PC/XT to the NC controller. As an example of integration of CAD and CAM technologies, the machining of a two dimensional hand-written free line which incorporates the processes of geometric data acquisition using a digitizing tablet, automatic part programming and control of NC milling machine operation is demonstrated.
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Recently, a quite large number of investigation is published on the subject of Flexible Manufacturing System which can cope with the volatile market demand and the variety of product. Minimum requirement of designing FMS is depicted and by investigating the communication system between the machine tool and the cell control computer, ana between the central computer and the cell control computer, when it is formed as a sub-system of an FEM, the software can be evolved to the control software of the total Flexible Manufacturing System. It is developed the communication system between the central computer and the cell control computer which is the basic structure of the control architecture of FMS under the concept of DNC (Direct Numerical Control). It is used CYBER 180-830 as the central computer, and GMC-1100 computer as the cell control computer, and the main basic program is developed and tested, thus forming a DNC system which can be used in educational environment.
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This paper presents a new method for generating smooth free-form surface by local correction. B-spline surface is used for its convenience of local correction, and the direction of surface correction is fixed to the average-surface-normal direction. The surface to be corrected is approximated into a uniform cubic B-spline surface. Then, the smoothness (curvature arrows, iso-parametric lines) of the approximated surface is displayed with B-spline control points. When a control point near the region that needs correction is selected, a new point 1 mm higher than the original control point in the direction of the average surface normal is displayed. And the surface is corrected by giving the amount of control point movement interactively. Since the direction of correction is given by the program and the amount of correction is selected by the user, the method is called semiautomatic. sufficiently smooth surface can be obtained by this method. Examples are given to illustrate the method.
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A study on the development of the computer aided part programming system 'AUTO-CUT' for wire-cut EDMThis paper introduces the system AUTO-CUT for the automatic generation of NC tapes for wire-cut EDM (Electrodischarge Machining) parts. The information input to the system is the description of the part geometries, the tool motions and the cutting conditions etc. The system generates CLDATA. Also dynamic graphic display of the tool motions can be-performed on the screen.
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In this study, PC-based FEA system (Micro-STANS) running on the 16 bit microcomputer is developed. This system has powerful pre & post processing function using computer graphics, and is interfaced to AutoCAD system which is most popular PC-CAD system, making it possible to accomplish the concept of real integration between design and analysis. This system which has truss , beam plate & shell elements in the element library, can perform linear static analysis.
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This paper is concerned on kinematic analysis and simulation of an automatic feeding mechanism subjected by the motion of a curvilinear inverse can. The curvilinear cam is rotated by positioning a translating roller and the automatic feeding mechanism is moved to the sliding position by the motion of a campin fixed on the curvilinear cam. The curvilinear cam consists of two arcs of circles and two straight lines. The modular approach is used for the kinematic analysis of the feeding mechanism. As the first part of the paper for the motion simulation of the cam-feeding system, this paper discusses the algorithm to simulate the motion of the cam-feeding mechanism. The second part of the paper presents the state-of-art for the graphics-oriented CAD technique,
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This paper is concerned on kinematic analysis and simulation of an automatic feeding mechanism subjected by the motion of a curvilinear inverse cam. The main objection is the development of computer-aided design (CAD) program for simulating the motion of the cam-feeding mechanism using computer-graphics. A computer program CACAFS (Computer-Aided Cam and Automatic Feeding System) is independent of computer hardware used. The program is also interactive using a menu-selection technique. As the second part of the paper for the motion simulation of the cam-feeding system, this paper discusses the state-of-art for CAD. The first part of the paper presents the algorithm to simulate the notion of the cam-feeding mechanism.
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This paper presents a case-building algorithm which can control the design variables of which some variables are designated as the input (known) variables and the remainders are defined as the output (unknown) variables. The case-building algorithm can enhance the design ability by categorizing design case automatically. Common CAD programs for analysis and design of machine elements use a case-selection technique where a programmer set initially a few of design cases and users can only choose one of given cases. This paper also demonstrates the case-building algorithm by applying into CAD programs for power-screw design.
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This paper describes the development of an expert system for control system designs. Our CACSD expert system consists of 2 parts; one is the knowledge manager and the other is the CACSD package. The knowledge manager contains the inference engine and the control experts' knowledge. The CACSD package consists of the control algorithms used by the knowledge manager. The prototype system of our CACSD expert system is implemented on the IBM PC/AT and the results of tests are given in this paper.
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This paper presents the development of a microcomputer-aided design program for a digital control system. The program has been written in GWBASIC language which is suitable for Intel 8086II CPU with 640KB memory. By utilizing this program, sampling time, the number of bits A/D and D/A converter, and the stability for the digital control system carl be determined, To demonstrate the utility of this program, a microcomputer controlled precision temperature control system has been employed as an example.
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This study presents the methodology for the hierachical construction of digital control system which can be of practical value to a wide application of sequence control. Optimization of digital control system, programming of the system by micropascal, and simulation of a model program under test are discussed.
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The concept of FMS (Flexible Manufacturing System) has been widely used in discrete parts manufacturing environment. But, it is very difficult to analyze enotrol FMS due to its complex and dynamic behaviour. This paper describes a Simulation program for performance evaluation of FMS. The program is written in FORTRAN and is capable of simulating different configurations.
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This paper deals with a modeling of manufacturing system and a model analysis by a SIMAN language. A flow of production process is analyzed, and a mathematical model on the basis of the analyzed data is simulated by a SIMAN language. An object of this study is to achieve an optimization of production a reduction of cost, and an improvement of quality by a applicable line-balancing technique and an optimization technique in a real factor induced an analysis and synthesis of the result of simulation.
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This paper presents a ship navigation system and automated equipments on ship board, whose technology has been quite rapidly developing in recent years. The ship owners and builders are much interested in ship automation systems, due to their comfort, safety and lower life cycle cost in ship operation. Here the basic technology and structure of the system are described, also taken into account is the future trend on the development of the system.
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A simple hybrid circuit to control the two-phase AC motor of the nut-runners which employ the tightening torque control system is described in this paper. The circuit has emphasis on the low-cost implementation. The circuit constitutes of the V/F converter using a timer IC, the pulse width modulator using the fastening torque signal and the two-phase logic sequencer.
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A pressure tracking control of hydroforming processes, which is used in the precision forming of. sheet metals, is considered in this paper. The hydroforming of sheet metal is performed between the high-pressure chamber controlled by pressure control valve and the punch moving with constant speed. Since the pressure in the forming chamber is a critical factor to the quality of the product severely. It is important to control the pressure to follow a prescribed pressure trajectory, depending upon the material volume and shape of the parts to be formed. Taking into consideration of the volume chamge of forming chamber during the process and the nonlinearity of the electro-magnetic relief valve, a mathematical formulation of the model describing the dynamic characteristics of this model obtained. Based upon this model a PID controller is designed for the pressure tracking.
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In this study a computer-aided textile pattern design system is implemented and a control methodology of a dobby motion is studied. The described system allows the user to design various weave patterns through graphic editor and to simulate weaving by displaying the dummy weaving process on the monitor. In addition, if the yarn colors are specified it is also possible to analyze color weaves. Thus it can replace effectively a conventional. design tool, a design paper. The main features of the system are to design weave patterns, to show weaving effect, and to make lifting plan for the dobby motion control. In dobby motion control, the mechanical. control method conventionally used is not adequate for the loom which is linked with the computer-aided textile pattern design system, so an electromagnetic control method is proposed.
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The purpose of this study is to monitor and control the back bead width in arc welding with consumable electrode for reduction of the occurrence of weld defect. The temperature of a point on the weldment surface is selected, as a monitoring parameter, and measured by an optical infra-red sensor. The correlation between the back bead width and the surface temperature is experimentally obtained for various thicknesses of the weldment. The welding travel speed and the surface temperature are taken, respectively, as an input and an output of the welding process under the stable condition of arc. A PI control scheme to maintain the surface temperature at the desired level is proposed by the experimental study.
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In this report, automatic packing equipment for dairy milk is presented. For food industry, Pneumatic System is widely applied because of it's environments. So, for the actuation, signal processing and sensing of this auto-packer, all pneumatic equipments was applied.
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This paper is describes the improvement of the transient response of the electrohydraulic position control system which exhibit the over-damped characteristics. A new approach, Position Error Prefiltered Proportional (PEPP) control, is proposed and the computer simulation results for the transient responses are analyzed. Experimental results using Z-80 microprocessor are presented.
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In this study, digital simulation with nonlinear modeling is carried out to analyse the performance of a hydraulic servomotor system developed for the position control of a large inertia. Nonlinear element, such as nonlinear pressure flow relationships of servovalve, valve spool limits, nonlinear friction, and backlash and resilience of gear system are included in the simulation along with the dynamic characteristics of variable delivery pump compensation mechanism. Simulation results are compared with experimental results for both step and sinusoidal inputs. Independent of input magnitude, both results are in good agreement with minor differences in detail.
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The Auto Tuning Controller is designed using Fuzzy set theory. And to verify its validity it is Applied to the Auto Tuner of hydraulic Control System. Fuzzy Tuning Procedures are written by linguistic model and translated into C language formation by preprocessor. Then it is executed with state feedback controller in real time, Fuzzy Logic Controller adjusts state feedback gain by proper tuning logic in each step to satisfy the desired maximum overshoot and settling time.
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It is widely noted that pressure feedback systems have been devised to damp the fluid resonance effectively in precision speed control-for large inertia system. A compensation technique preserving the natural output disturbance discrimination characteristics at lower frequencies is proposed The load pressure across positive displacement acceleration. The technique involves feeding back load differential pressure, sensed by pressure transducers, though a simple analog compensatory circuit (high pass filter). The effectiveness of the damping is determined by the filter time donstant and loop gain. Nonlinear total hydraulic simulation results verify the possibility of linear model predictions of extending the closed loop bandwidth beyond the uncompensated frequency.
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It has recently shown that a solenoid valve can be utilized in a hydraulic position-control system by discontinuous control methods. The objective of this study is to investigate the effects of solenoid valves on the response characteristics of a hydraulic position-control system by applying two kinds of discontinued control methods i.e., Simple On-Off (SOF) and Pusating On-Off(POF) controls. Three types of solenoid valves i.e. low-frequency, closed-center type (LF/C), high-frequency, closed-center type (HF/C), low-frequency, tandem-center type(LF/T) were used in this study. Effects of loading conditions and control parameters on the response characteristics were experimentally examined and compared each other. Pressure transients within the actuator were also studied.
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Damping piston with an orifice in the piston head is utilized to improve the damping characteristics of a pneumatic push-push type rotary actuator. Through linearized analysis, the optimum size of orifice, which gives maximum damping effect at the frequency where damping is desired. most, is predicted. The frequency response test of teal system were carried out to see the effects of damping piston and to obtain true optimum size of orifice by trying orifices of various size near the predicted value. During the tests, both air and helium were tried as working fluid, and a lag-lead compensation circuit was incorporated to improve system dynamics. The finally chosen orifice size is a little bigger than that predicted from analysis, however it gives high damping effects for the finally designed pneumatic system enough to have wide frequency response bandwidth.
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There are many kinds of intelligent devices on the factory floor nowadays. Standardized communication methods became a necessity for efficient flow of production information among various systems. MAP (Manufacturing Automation Protocol) based on ISO (International Standard Organization) OSI (Open Systems Interconnection) is gaining acceptance of major industries worldwide.
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In this paper, the performance of Mini MAP architecture is analyzed by simulation method. Token rotation time and waiting time are obtained by simulation. The results of the simulation are compared with these of the analytic model. From these comparisons, it is shown that simulation results are approximately identical to analytic results. Mini MAP architecture has good real time performances in token rotation time and waiting time and can be used to many real time applications.
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This paper describes the configuration of serial interconnection BUS, BitBUS, for Energy Management Systems, and it provides low cost, high performance approach in distributed data acquisition and control applications.
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This paper presents an analysis of the man-machine control system. A man-machine system depends on the performance of a human operator for proper operation. The analysis method is based upon the assumption that human operator will act in a near optimal controller. Optimal control theory and its associated state space representation is used as the basis for the analytic procedure. The computer simulation for a given plant shows that plant parameters have limited range by the human operator.
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In the process industries control & organization consist of interconnections on different levels. The process controls that run these industries are a collection of well-defined functions in the form of standard modules interconnected by a communication network. Real-Time(throughput, response time), operator communication, flexibility, back-up and recovery needs have distribute organization of both system hardware and software. Multi-level systems are aften advocated for controlling complex systems, such as, electric, water, oil, gas plants. In practice, these systems encompass computers and person with their various communication requirements and limitations. Hence, Careful mutual adaptation of computer communications and organizational structure is necessary. This paper concentrates on these interactions between process control and organization on the basis of industrial case studies.
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In this paper results of program development which has been carried out for the purpose of increasing availibity of SCADA system in KEPCO is reported. In particular program development for automatic logging of trip load in powter transmission line is included.
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A large scale programmable controller is developed which adopts a multiprocessor structure. The developed programmable controller consists of the programmer, the system controller, and the input-output unit. The structure and characteristics of the system controller will be described. The PC has a special hardware scheme to solve the Boolean logic instructions of the sequence control programs. The multiprocessor structure and the special hardware enables, the real time operation and the high speed scanning which is prerequisite to the large scale, programmable controller even for many I/O points.
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The software developed for the large scale Programmable Controller consists of the programmer's S/W, the Controller's S/W the RBC's (Remote Base Controller's) S/W and the Analog's S/W. The programmer's S/W, running on the Programmer, includes the editor, the compiler, the communication program, and some other programs for easy use. The Controller S/W, which requires the fast scanning time, consists of the BTI( Block Type Instruction) solving program, the timer service routine, the i/o update program, the communication program and etc. The RBC's S/W includes the communication program, the error recovery program and the i/o processing program. The analog S/W, controlled by the Programmer, includes the PID program. The data communication between the Programmer and the Controller the Controller and the RBC, and the RBC and the Analog are developed.
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The high-speed tendency of Programmable Controller requires a fast processing of instruction. This project investigate the instruction execution system for a fast processing in Programmable Controller.
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Auto-programming of sequencer was implemented by PLC-.mu.C system, to transform the PLC program in the relay ladder diagram.
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The reliability is the critical issue in many computer applications, particularly in process control system. In this paper we describe how to achieve the reliability improvement in controller system based multiprocessor. The proposed method is accomplished by using the techniques of fault detection, fault isolation, safe action, and fault diagnosis.
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In this paper, the development of an One Loop Controller is described. The functions which are built in the One Loop Controller are summarized and the hardware implemention of these functions using 16 bit microprocessor is described. The developed One Loop Controller is applied to DC_Motor based position control system and it's results are given.
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We have studied a new technical approach for the design of digital FIR filters with flatness in the passband, and equiripple attenuation in the stopband using the program of J.H. McClellan, T.W.Parks, L.R.Rabiner and the flatness property. The design technique directly loads to structures that have low passband sensitivity properties.
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In this paper, a new ARMA spectrum estimation algorithm based on Circular Lattice filter is presented. Since APMA model is used in signal modeling, high-resolution spectrum can be obtained. And the computational burden is reduced by using Circular Lattice filter. By modifying the input estimation part of other proposed methods, we can get high-resolution spectrum with less computation and less memory compared with other Lattice methods. Some computer simulations are performed.
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In this paper, overdetermined method is used for high resolution spectral estimation in case of short data record length. To reduce the computational effort and to obtain recursive form of estimation algorithm, we modify data matrix to have near-Toeplitz structure. Then, new recursive algorithm is derived in the form of fast Kalman algorithm. Two stage procedure is used for the estimation of ARMA parameters. First AR parameters are estimated by using overdetermined modified Yule-walker equation, and then MA parameters are implicitly estimated by estimating numerator spectral coefficients(NS).
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In this Paper, recursive least-squares lattice algorithms for prewindowed given data case are considered, and some experimental results to linear prediction, the sequence of monthly electrical power sales is taken as time series, am presented.
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본 논문에서는 파워스펙과 Bispectrum의 차이를 이론적으로 비교 검토하고 파워스펙트럼에서는 알 수 없었던 주파수 성분간의 간섭 및 시스템의 비선형성 등을 컴퓨터 시뮬레이션을 통하여 Bispectrum 해석법의 물리적인 의미와 그 타당성을 규명하고자 한다. 시뮬레이션에 사용한 데이터는 주파수에서 Harmonic Order를 갖는 회전기기의 특성을 기준으로 한다.
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The Kalman filter is an optimal linear estimator that has been an active research topic for the past three decades. The scheme has become the milestone of modern filtering, and it is applied to many areas including navigations and controls of free vehicle. The Kalman filter technique is matured. But some problems are still remained to be resolved. The prevention of divergence induced by digital implementation, nonoptimal application for nonlinear system, and application to non-Gaussian processes are some of the problems. This paper surveys the problems. The square root filtering is suggested to prevent the divergence. The extended Kalman filter is used for nonlinear systems. And, many other approaches to Kalman-like optimal estimators are also investigated.
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This paper deals with the continuous-discrete estimation problem using FIR filters and performs modeling error analyses of the FIR filters, compared to Kalman filter and the limited memory filters, via computer simulations. It is shown that, the less driving noise the system has, the better performance the FIR filter exhibits and that this characteristic appears rare distinctly in nonlinear system than in linear systems.
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The purpose of this study is to design a phoneme-class recognition system for Korean language using filter-bank analysis and zero crossing rate method. First, the speech signals are separated in 16 bandpass filters to obtain short-time spectrum of speech signals, and digitized by 16-ch A/D converter. And then, with the set of features which extracted from patterns of ratios of each channel energy level to overall energy level, the decision rules are made for recognize unknown speech signal. In this experiment, the recognition rate was about 93.1 percent for 7 vowels under multitalker environment and 74.4 percent for 10 initial sounds at single speaker.
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The reducers are widely used to reduce output speed and to amplify driving torque of actuator for industrial robots and many industrial units. But the vibration of robot, which is affected by the reducer, becomes a problem for robot which has to move a driven part with high accuracy. This paper compares experimentally the vibration characteristics of the reducer for industrial robot.
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In order to measure object larger than the optical field-of-view most video measurement systems utilize some sort of precision staging mechanism, and to utilize such a staging systems, Auto-Measurement System implemented in this paper has a precision of its own which affect the overall repeatability of the measuring instrument.
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In this paper. a heuristic multi-thresholding algorithm is proposed to extract objects from background. Specifically the proposed algorithm finds out multi valleys from gray level histogram automatically and non-recursively. Some experimental result for various types of image. are presented, to show the effectiveness of the proposed algorithm.
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The testing philosophy and control schemes are investigated and applied to construct the Automatic Microwave Leakage Inspection System (AMLIS) . AMLIS is consists of three major parts such as Material Handling Mechanism, Fine Positioning Mechanism and Scanning Mechanism. The material Handling unit is designed to perform loading and unloading microwave oven onto the testing point by pneumatic cylinder and vacuum pump. The Fine positioning part includes X-Y-.THETA. table and distance sensing equipment. The scanning part is composed of five SCARA robots, which traverse X-Y-Z catesian coordinates respectively. The leakage testing probes are placed at the end of this each robot then the path and speed are both controlled via microprocessors. A performance test of this system combined with electric parts and software is done and the basic major function of system are accomplished.
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A new concept in resolver-to-digital conversion is described, which is based on the digital phase locked loop(DPLL). This converter receives phase modulation and converts it into digital form using time ratio techniques. In this paper, the theories on DPLL and resolver and the design of the converter are covered.
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In this paper, we dealed development of analytic tools for strapdown inertial navigation system. It classified the constitution of strapdown inertial navigation system and the tests of productions. It is useful to high precision instrument.
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Input/output equations in SDINS IMU are modeled from survey of IMU data flow. Given without precise equipments which can generate acceleration and angular velocity, a simple method is derived to calibrate the parameters of i/o eqijations. Also in order to upgrade ins performance, methods to estimate variant magnitudes of time variant parameters are surveyed.
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In this paper the error equations of the SDINS aligned by the gyrocompass are derived considering that the alignment errors are correlated to the sensor errors. Also the navigation errors due to the correlated errors are simulated by this error equations. The simulations are performed by the covariance analysis method, assumed all the sensor errors are random constants. The simulation results show that while the INS maintains the alignment attitude the cancellation takes place between the correlated errors, but once the INS changes attitude this cancellation effect is perturbed.
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Among the gyroscopes used for SDINS, the dynamically turned gyroscope (DTG) covers a wide dynamic range while it is simple and small. In addition, it is a two-degree-of freedom gyro; it can detect two-axis input simultaneously. DTG, since its development in 1970's, is widely accepted for strapdown inertial systems. In the first year, we have concentrated on developing a two degree-of-freedom DIG. An interdisciplinary research team has been formed to accomplish the first year objective. Five departments in the College of Engineering, Seoul National University are involved. They are; 1) Department of Control and Instrumentation, 2) Department of Mechanical Design and Production, 3) Department of Electrical Engineering, 4) Department of Electronic Engineering, and 5) Department of Metallurgical Engineering. In addition, the Department of Precision Mechanical Engineering of Pusan National University is subcontracted to develop a test procedure for gyroscope and SDINS. Gyroscope is a key sensor for SDINS. Furthermore gyroscope itself is used as a. independent sensor for vehicle guidance and control and fire control system. Gyroscope and SDINS are an important for defense, aeronautical, and space industries that Korea is and will be actively involved. Upon the success of the project, they are expected to be manufactured in Korea under a cooperative effort between university and industry.
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This paper describes the hardware of analog-to-digital converter to process the rate output of analog servo loop for the gyro rebalance of INS. The analog-to-digital converter is designed by voltage-to-frequency method which is generally used in INS, and this scheme fits well into the strapdown INS that requires the wide dynamic range and linearity. The output of the designed voltage to frequency converter is tested by computer through the counter and all the factors which affect the performance are considered.
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Closed-loop fiber-optic gyroscope with linear scale factor for a wide dynamic range is demonstrated using a gating process and two-harmonic phase modulation, of which the second harmonic is obtained by a frequency doubler. Also the effects of the second harmonic and duty cycle of gating signal on the linearity of scale factor are estimated theoretically and compared with the measured data. The experimental results show the best linearity of scale factor is about 0.5% within the rotation rate 90.deg./sec. The closed-loop fiber-optic gyroscope with gated two-harmonic phase modulation can be used in the application demanding less sensitive performance and modest scale factor linearity.
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우리나라의 경우 GMS와 INTELSAT에 이미 가입되어 있으며 LANDSAT이나 SPOT의 자료도 사용가능하다. 최근에는 통신량의 급증과 TV송신 때문에 DOMSAT가 고려되고 있으나 경제적 타당성이 문제가 되고 있다. 이러한 시점에서 저렴한 가격으로 DOWNSAT의 역할을 대행할 수 있는 HALEP의 의의는 중대하다. HALEP의 대상으로는 TETHERED BALOON, AIRSHIP, 고정익기로 고려할 수 있는데, 그 중 고정익기를 주로하여 유사사례들을 살펴보고 개발 방향을 논의하고자 한다.
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항공기가 평형상태로 비행하는 도중 돌풍과 같은 외부교란을 만난 교란상태운동은 선형화된 미분방정식으로 표현되며 비교적 짧은 비행시간동안의 비행은 선형시 불변계가 된다. 돌풍은 Gauss-Markov확률과정으로 모델링 되며, 항공기가 돌풍을 만난 교란상태운동은 시스템론적으로 보면 백색잡음이 성형필터를 거쳐 계에 입력되는 것과 같다. 초기의 설계방법은 고전적인 주파수영역에서의 해석방법을 사용하였으나 1960년대에 최적제어이론이 도입되면서 평가함수를 사용하여 원하는 비행특성을 얻는 방법을 사용하게 되었다. 그 후 계에 입력되는 외란과 측정시의 잡음으로 인한 불확실한 측정량으로부터 최적상태변수의 추정을 위해 필터링이론을 도입한 확률제어이론을 적용하여 자동조종장치를 설계하게 되었다. 이때까지는 연속제어계로 설계되었으며 그 후 측정신호를 샘플링하여 연속제어계와 등가의 이산제어계를 사용한 자동조종장치가 등장하였으며 이 경우 설계기법으로는 연속제어계를 사용하고 실현시킬 때는 디지털컴퓨터를 사용하였다. 이는 제어하는 동안 계의 계수와 제어법칙을 바꾸어 줄 수 있는 이산제어계의 장점을 이용하지 못하므로 처음부터 계를 등가의 이산계로 보고 제어계를 설계하는 방법이 도입되었다. 이 때 샘플링간격의 결정과 Quantization 영향이 설계시 고려되어야 한다.
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An experimental study has been conducted to investigate the suction performance of a designed inlet. Total pressure distortion in the inlet S-duct was measured and the effect of lip thickness and throat area was analyzed. The volume flow rate of air into the turbojet engine was controlled to observe the effect of engine RPM to the total pressure distortion. The pressure data from 36 air tubes were obtained using scanivalve, pressure transducer, and visicoder system.
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The purpose of this paper is to present an efficient and practical method for a Hissle autopilot design problem. The method emphasizes on the use of a modern design technique to classical flight control specifications and the trade-off between dynamic performance and robustness of the Missle autopilot control system.
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In this study, the construction process of a two-panel space station and its control problem are discussed. The appliability of direct model reference adaptive control technique with plant augmentation is investigated. Regulator control problem with high initial transient has been simulated Result show that high rate of convergence has been observed for all the simulation.
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This paper presents a suboptimal Kalman filter design method for the problem of tracking a maneuvering target. The design method is essentially based on linear target dynamics and linear-like structured measurements called pseudomeasurements. The pseudomeasurements are obtained by manipulating the original nonlinear measurements algebraically. The resulting filter has computational advantages over other filters with similar performance. Monte Carlo computer simulation results are included to demonstrate the effectiveness of the proposed suboptimal filter associated with the target acceleration model.
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This paper addresses the development of the estimation algorithm to acquire target position, velocity and course using bearing-only measurements in two dimensional environment. System state equations are derived from modified polar coordinates instead of existing Cartesian coordinates system. The Extended Kalman Filter is used to constitute the estimation algorithm because of state equation's nonlinearity. The computer simulation is done to verify the performance of derived algorithm. Simulation result showed that estimated state value of filter was converged to the true value in 10 minutes.
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The primary difficulties encountered in the use of step motors are underdamped response when stopping at a specified position and dynamic instability during high-speed slewing. This paper proposes a speed and position detection scheme using the back EMF generated by the rotating permanent magnet field of a two-phase 1.8.deg. hybrid step motor, and presents its application to the state-variable feedback control of the hybrid step motor. All simulation results in a single step response show that the hybrid step motor performances such as peak overshoot and settling time are greatly improved.
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The robust servo controller is designed by the procedure of LQG/LTR method in the continuous-time domain. This design results is equivalently converted to the discrete-time suboptimal LQG in order to implement by the microcomputer system. The LTP, condition of the discrete-time LQG is analyzed and approved by the experiments against the uncertainty of real plant, the discretized LQG /LTR control shows the good robustness.
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A new control method for DC motor position control with variable structure is presented. The proposed method uses the desired trajectory with optimal input satisfying the given performance requirement as the switching curve and is insensitive to parameter variation and disturbance. To show the validity of the proposed method, digital computer simulation is performed. And the result is compared with that of the optimal state feedback.
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하이브리드 스텝 모터와 같은 소형 정밀 모터에서 이를 설계 제작하는 과정에서 가공기술의 부족과 높은 생산 단가로 인하여 모든 부분의 가공에 높은 정밀도를 유지하기는 어렵다. 그러므로 토오크 특성에 영향을 많이 미치는 부위의 가공 정밀도를 향상시킴으로써 생산 단가를 줄일 수 있다. 하이브리드 스텝, 모터에서 구조상의 오차는 모터의 PERMEANCE를 변화시키고 PERMEANCE의 변화는 이와 직접적인 관련을 갖고 있는 토오크를 변화시켜서 결국에는 스텝 모터의 가장 중용한 요소인 정확한 위치 제어를 할 수 없게 된다. 모터의 구조적 결함에 대하여 알아보고 이 과정을 통하여 구한 HOLDING 토오크 값으로부터 정상인 때와 구조적인 오차가 있는 경우에 대한 토오크의 최대치와 DETENT 위치를 서로 비교함으로써 오차에 대한 토오크의 영향을 해석한다.
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In this paper, a controller design method for the DC motor driving system is described emphasizing the specified degree of accuracy undergoing large time varying disturbances, coulomb friction and arm-load resonance. A feedforward compensation technique using the current controller is proposed, and resulting in the performance improvement as well as the implementational simplicity. A time-weighted quadratic performance index is used in the optimization of the controller, which is a salient way of obtaining better closed-loop performance in a simple manner. Computer simulations are also given to show the usefulness of the proposed techniques.
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In this study, direct-drive position controllers are designed and implemented for the flying vehicles actuating system with both positive and negative load factors, where the load factors are assumed proportional to the deflection angle of control surface. Its analog and digital controllers are verified through software simulation and hardware-in-the-loop simulation.
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In this study, a method of obtaining reasonably large and constant torque at high speed is given in order to improve the performance of the open loop controlled step motor system using the current source, thus resulting in high performance compared to the conventional current limiting using resistor and chopper.
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This paper proposes a voltage-fed high frequency resonant inverter having variable voltage variable frequency(VVVF) control function. VVVF control is performed by PWM-TRC method in the boost type chopper and PFM-TRC method in the high frequency resonant inverter. This circuit is suitable for induction heating and melting power supply in industry. The operating characteristics of this inverter are discussed from a theoretical point of view. The results of operating characteristic analyses are given leading to complete designing data.
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A simulator is designed in order to evaluate the performance a f a lockup controller. The original analog controller and boiler plant are transformed into digital form model, in which the plant is modeled as a 2 input-2 output system connected to first order peripheral units. The experimented results show that the simulated system renders the same steady state characteristics as data and show usability of simulator.
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This study is concerned with the improvement of the Automatic Boiler Control and Turbine Governor system to maintain line - frequency within 60 .+-. 0.1 HZ. This describes the current problems of plant control system, the method and equipments to be developed for each plant based on the experimental test were carried out at field, and, lastly, the results of the study with the progress of it.
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Rod consolidation is a method of increasing spent nuclear fuel storage capacity by disassembling fuel assemblies thus storing the fuel rods in a tighter array. It involves some basic operations which closely resemble to the material handling of a manufacturing process. But all the operations must be controlled remotely in shielded environment from outside due to the highly radioactive nature of the workpiece. In this study the status of the rod consolidation technology in other countries has been surveyed and a feasibility study for the conceptual design of this process have been made.
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A study on distribution automation system suitable to distribution system of KEPCO has started since 1984, and the field trial system for ADS will be operated for testing. This paper will describe project and planning for field trial of KEPCO.
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Technology associated with power plant control system has been heavily rely on foreign technology. The main reason is that the system has tomaintain stringent reliability and stability. Localization of this system can be started from localization of modules necessary for maintenance and repair in hydraulic and thermal power plant. Gradually and eventually system engineering capability can be built up to design and develop nuclear power plant control system through technology accumulation. Methods are presented to achieve this goal.
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The design of ultrasonic transducer energy processing systems requires highly reliable command featuring mechanical frequency tracking and constant velocity control of the ultrasonic transducer with an acoustic load. This paper presents a new conceptional instantaneous current resultant control base high-frequency inverter using self turn-off devices driving an electrostrictive ultrasonic transducer system and its optimum control technique, which is implemented by feed-back of the ultrasonic transducer applied voltage and instantaneous velocity of the transducer vibrating system through a Phase-Locked-Loop control scheme. The feedback voltage corresponding to instantaneous velocity is averaged over a half-period with respect to constant amplitude/constant velocity control strategy. Described are the theory of this signal detection technique and the experimental set-up.
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In immobilized cell reactors, effective cell mass is a very important parameter which must be estimated during operation for control and regeneration of biocatalyst. In this report, the effective cell mass in immobilized cell reactor was studied using a sequential estimation method. An immobilized yeast reactor was operated in batch recycle mode. The states of the immobilized cell reactor could be estimated from the process data using an extended Kalman filter.
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A criterion is developed for the, selection of the best pairing of the control and manipulated variables and for the interaction analysis of decentralized multi-input multi-output control systems. This criterion is based on the difficulty caused by the interaction terms in finding the in-verse of the block steady gain matrix. A quantitative measure of the best pairing is obtained from the resemblance of a set of independent block multi-loop systems. Several examples show the validity of the pairing criterion.
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Yeast biomass in a biological continuous stirred tank reactor was controlled with an APPLE II microcomputer using adaptive control theory of bilinear systems. The controller used is as simple as a PID controller, but required less information. Cell concentration was well controlled by adjusting the inlet flow rate following the algorithm.
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The Dynamic Matrix Control(DMC) technique was applied to nonlinear and nonminimum phase system. System model was identified by using Least Square method. Desired output trajectory was prespecified and input suppression parameter was also introduced. It was shown that DMC technique worked with great success in solving both nonminimum phase system and nonlinear system.
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The new controller developed here, which is the facility with only one measurement, is a new concept for the level controller of the existing nuclear steam generator. A MACS (Microcomputer-based Adaptive Control System of a Steam Generator) is quite practical and efficient, and has also simple structure and higher flexibility in the installment for actual plant. A key ingredient of this system is adaptive regulator which can calculate adaptive, optimal valve position in response to changes in the dynamics of the process and the disturbances. In spite of many difficulties in the steam generator water level control at low power, it can be concluded from the experimental and simulation results, that the MACS can provide optimal, robust steam generator level control from zero to full power. The amount of the control input effort can be reduced by adjusting the weighting factor. However, the steady state water level errors are generated. To avoid the steady errors, the different adaptive algorithm should be investigated in the future. The 3 second sampling time is acceptable for this system. However, action should be taken to shorten the sampling time for better digital control.
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In this study, the computation of optimum operating conditions for catalytic oxidation of sulfur dioxide to sulfur trioxide in CONVERTER which determines the yield ultimately in sulfuric acid plant is performed on an IBM/XT computer. The process simulator of rigorous converter model including mass & energy balance equations and supporting equations is linked to optimizer, which produces the desired results successfully.
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This paper deals with the automation of the brewing process using digital computer. The work has been carried out to develop real-time control software for fermentation process. From the application of the system, quality improvement and effective process management are achieved.
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The structure of chemical process has become increasingly complex, due to better management of energy and raw materials. As a consequence, the design of control systems for complete plants now constitutes the focal point of engineering interest, rather than controller designs for single processing units. Instead of traditional methods based on complex mathematical model, chemical processes are represented by structural array and cause-and-effect graph to apply non-numerical problem-solving techniques. A systematic logical procedure to synthesize alternatives of control system structure and some heuristic rules to select a feasible solution from the vast number of alternatives that are possible are considered in this study.
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Process failures can occur at any time during operation, so a continuous effort of fault detection, diagsis, and correction is required. Expert system paridigm has been regarded as a promising approach to real time process supervisory control especially to fault diagnosis. The most important aspects of fault diagnostic expert systems(FDES) are the problem-solving inference strategy and knowledge organizations. The necessity of FDES, the nature of diagnostic knowledge, the representation of knowledge, and the inference mechanism of FDES, et al. are described, which are announced by previous researchers. And the existing FDES are categorized and critically reviewed in this work.
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The speech signal processing in the auditory system can be analysized based on two representations : Average discharge rate and Temporal discharge pattern. But the average discharge rate representation is restricted by the narrow dynamic range because of the rate saturation and the two tone suppression phenomena, and the temporal discharge pattern representation needs a sophisticate frequency analysis and synchrony measure. In this paper, a simple representation is proposed : using a model considering the interaction of Cochlear fluid-BM movement and a haircell model, the feature of speech signals (formant frequency and pitch of vowels) is easily estimated in the Average Synchronized Rate.
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Digital Subtraction Angiography(DSA) technique has been widely used to detect vascular diseases and hemodynamic parameters noninvasively. However, there are few quantitative studies on the factors in fluencing the resultant DSA image quality. In this paper, several important factors are suggested to improved the DSA image quality based on mathematical analysis. Experimental DSA images for different filters are shown and also discussed the difference between original and processed image quality.
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Base-line wandering and 60Hz noise in ECG are removed by linear phase FIR filter. The important problem in FIR filtering is to reduce the number of impulse response coefficients. It can be reduced by symmetrical impulse response. The ripple is improved by window function .omega.(n). And the determination of filter accuracy is proposed by PRD(percent rms difference) algorithm.
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In this paper, the primitive and double combined motion classification of the arm is discussed using pattern recognition of EM signal. The EM signals are detected from Ag-Ag/Cl surface electrodes, and IBM PC, calculated the Likelyhood probability and the decision function on the feature space of integral absolute value. Multiclass decision rule is introduced for higher decision rate. On our experimental results from expert simulator, the decision rate of more than 78% can be obtained.
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This paper deals With the EMG signal processing to apply the EMG signal to the Prosthetic arm. The EMG signals are generated by the voluntary contractions of the subject's musculature and is coded into binary words by the pulse width modulation. Command strings or sentences are constructed by concatenating several words, and are syntactically described by a context free grammar in Chomsky normal form and is tried to classify the movement pattern by the CYK algorithm.
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In this paper, a mathematical model for the purpose of QRS detection is considered in the case of the occurrence of nonoverlapping pulse-shaped waveforms corrupted with white noise. The number of waveforms, the arrival times, amplitudes, and widths of QRS complexes are regarded as random variables. The joint MAP estimation of all the unknown quantities consists of linear filtering followed by an optimization procedure. Because of time-consuming, the optimization procedure is modified so that a threshold test is obtained. The model formulation with nonoverlapping waveforms leads to a standard procedure covering a segment before as well as after an accepted event. Adaptivity of the detector is gained by utilizing past signal properties in determining threshold for QRS detection.
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A new approach to the real-time measurement of muscle fatigue by using adaptive filtering algorithm is proposed. Unlike previously reported methods, it can estimate the muscle fatigue at every sample as the EMG signal statistics change. As a result, the muscle conduction velocity ranged between 4.2-5m/s at low tension and 3-4m/s at fatigue state.