• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.1119-1126
• /
• 2000

This paper is concerned with the design and application of an Electro-Rheological(ER) fluid damper to suppress the vibration of a rotor system. The system is flexible with a slender shaft and a thin disk, being supported by two ball bearings. In addition, to investigate the system performances also in the high speed range, the driving torque is made transmit through a speed increasing gear train. Along with the experiments, to predict and compare the ER damper effect, the rotor system is simulated as to its free and forced vibration characteristics by means of a finite element method code, which is assembled with the mathematical model of the designed ER damper.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10a
• /
• pp.145-148
• /
• 1990

In this paper, the problem of designing a feedback controller for a robotic manipulator, which is activated by a D.C. motor through a gear train and a flexible shaft or chain, is considered. When the response of the closed loop control system is relatively slow, a satisfactory controller may be designed as a PID controller. As the speed of the control system increases, however, the spring effect of the linkage becomes profound, and as a result, the transient response exhibits a substantial oscillation. To eliminate this oscillation, it is necessary to design the controller based on at least a fourth order system model. This, in turn, requires the feedback of the entire state variables. In practice, however, only the position of the manipulator and the velocity of the motor are readily measurable. The state variable reconstruction method or a state observer cannot be used because of the system nonlinearities such as the Coulomb frictions. In this study, an alternative controller, which is based on delayed feedback of the output variable only, is proposed, and a successful delayed feedback controller is designed and implemented on an actual experimental manipulator.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.8 no.4
• /
• pp.136-142
• /
• 2009

The vehicle's light-weight technology is divided into optimization of structure geometric and material. Structure geometric optimization and improvement of materials has examined to be power-train and maintenance on the severe condition. The core technology of Special vehicle's light-weight is constitute by Drop box, Axle and Final reduction gear. Technology and product of the parts is high to overseas and import dependency. We will want to examine the possibility of light-weight for the Axle Case and Drop box-connections. In this research, conventional design of excess weight will inhibit the mobility and fuel efficiency. Through the improvement of Axle material, we saw the possibility reducing weight. If you use the results of these studies, it will be available to domestic production technology and reducing weight of RV car, Dump truck, Track crain, etc.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.04a
• /
• pp.71-76
• /
• 2011

In this paper, we investigate the vibration source of sheet feeding apparatus installed in scanner cover of the digital MFP through frequency analysis. Gearmesh frequency and motor generated frequency were calculated to analyse autospectrum. During driving state, we measure the vibration level. It was found from the signal analysis that gearmesh frequency and motor generated frequency are identified as vibration source.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.10
• /
• pp.73-80
• /
• 1998

Recently, we have developed a linear brushless DC motor(LBLDCM) with high speed and precise position control performance to apply it to the semiconductor assembly and inspection machinery. It is composed of double side alignment by two armature-stator pairs and each pair is consist of a moving armature with 8 poles by 3 phase coils and a stator with rare earth permanent magnet (Nd-Fe-B) arrays. Through the thrust force analysis on a simplified and whole model of the suggested LBLDCM by an Electromagnetic FEM solver, skew angle of magnet arrays to reduce the thrust force ripple and the winding conditions of the armature is designed. From experimental results, the user's requirements was satisfied and we confirmed distinctly that the repeatable accuracy less than a micron of the linear motion can be obtained at high speed by the developed LBLDCM. This is owing to directly drive the work without the gear train.

• Journal of Industrial Technology
• /
• v.20 no.B
• /
• pp.95-103
• /
• 2000

A model trains must have similitude with its original model not only in shape but also in motion. Motion characteristics of a model train under considerations are maximum velocity in straight and circular tracks and stopping distance. Equations of motions are derived to obtain maximum speed and stopping distance based on the Newton's Second Law and the energy principal. To accurately predict traction and resistance force between wheel and rail. wheel slip, or creepage, is taken into consideration. To verify the equations of motion, various experiments have been carried out including measurement of gear efficiency, location of mass center, rolling resistance force, traction force, slip, maximum velocity and stopping distance. This paper addresses how the experiments are setup and carried out in detail. Also the results of experiments are compared with the analytical prediction, which showed good agreements with each other.

• Proceedings of the KSR Conference
• /
• 2003.05a
• /
• pp.433-438
• /
• 2003

The recent operating trains including the high speed train are mostly moving system on the rail and system use the mechanical propulsion force to drive the gear and wheel by the traction motor. Advanced countries are interested in Magnetic Levitation Vehicle and they have been studying about it continuously. Thus this paper is analyzed the feature of analysis the feature for Linear Induction Motor as the propulsion equipment of Magnetic Levitation Vehicle. And the Magnetic Levitation Vehicle is being developed for the transportation system of next generation using the Finite Element Method

• Korean Journal of Applied Biomechanics
• /
• v.17 no.3
• /
• pp.225-232
• /
• 2007

This work intends to investigate the effects of shift characteristics on the propulsion performance of a manual wheelchair with an automatic transmission. A planetary gear train is employed to generate a two-stage shift automatically, based on the distance traveled from rest. Motion analysis has been performed for measuring kinematic properties of the arm and then the inverse dynamics has been applied for estimating joint forces/torques. Then, a parametric study has been performed to find a set of the shift ratios and the shift intervals for optimizing propulsion performance. Results show that the propulsion performance is closely related to the shift condition. It is found that a short shift interval is desirable for a short distance propulsion. However, an optimum shift interval for a long distance propulsion is inversely proportional to the shift ratio approximately. Consequently, the automatic transmission can greatly lower the joint loadings by the speed reduction, which eventually contribute to prevent joint injuries of wheelchair users.

• Journal of the Korean Society of Mechanical Technology
• /
• v.13 no.3
• /
• pp.17-23
• /
• 2011

To estimate fuel consumption of a vehicle, a car can be tested on chassis dynamometer. In this case, test causes a lot of time and money. To predict the fuel efficiency of vehicles in the design stage or early stage of development, the development of computer simulation model is necessary. Using simulation to predict the fuel consumption, the driving model which consists of time-velocity profile and time-grade profile is necessary In this study, vehicle model is developed in MatLab/simulink to estimate real driving fuel consumption rate with time-velocity profile, time-shift gear profile and time-grade profile. Vehicle model consists of driver model, engine model, power train model, and so on. On-road vehicle tests to verify the vehicle model are carried out for analyzing the result of simulation and comparing with those of the experiments.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.7
• /
• pp.115-121
• /
• 1996

Multi-axes driving system is more suitable for FMS(Flexible Manufacturing System) compared with a conventional single-azis driving system. It has some merits such as flexibility in operation, improvement of net working rate, maintenance free because of no gear train, etc. However, studies on position synchronous control for high precision in the multi-axes driving system are not enough. In this paper, a new method of position synchronous control is suggested in order to apply to the multi- axes driving system. The proposed method is structured very simply using speed and position controller based on PID control law. Especially, the position controller is designed to keep position error to minimize by controlling either speed of two motors. The effectiveness of the proposed method is successfully confirmed through several experiments.