• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2646-2653
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• 1993

A rotational torque calibration system is developed to measure rotational torque of power generating systems and to calibrate non-contact rotational torque measurement systems. The maximum capacity of the developed system is 4.5 N-m. It is composed of a DC motor, a DC generator, a control system, a master torque cell, a slip ling/brush set, supporters, a bed etc. The control system is characterized by the closed-loop control with differential intergrator. Rotational torque measurement test and unit response test are conducted to estimate the accuracy of the developed system. It is found that system maintain high consistency and accuracy with the maximum error of 0.25%, Therefore the developed system can be used to measure the rotational torque of power generating systems and to calibrate non-contact rotational torque measurement systems.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.168-172
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• 2001

The accuracy problem of robot manipulators has long been one of the principal concerns in robot design and control. A practical and economical way of enhancing the manipulator accuracy, without affecting its hardware, is kinematic calibration. In this paper an effective and practical method is presented for kinematic calibration of Stewart platforms. In our method differential errors in kinematical parameters are linearly related to differential errors in the platform pose, expressed through the forward kinematics. The algorithm is tested using simulated measurement in which measurement noise is included.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.1
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• pp.67-73
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• 2010

Finding sufficient supplies of clean energy for future is one of the society's most important challenges according to technologies. Alternative renewable energy source such as sun energy can be substituted for exceeding human energy need. The main factor affect to solar performance is a collective intensity. To enhance intensity, suitable equipment is a solar tracker. This paper presents design and evaluation of 1 layer polar motion control system for solar tracker suitable for building integrated system. To evaluation of tracking accuracy and adaptability, solar tracker with 64 links is implemented. In experimental results, the accuracy of tracking has under ${\pm}0.0287^{\circ}$ and the thickness has under 140mm.

• Journal of the Semiconductor & Display Technology
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• v.1 no.1
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• pp.21-28
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• 2002

This paper presents a dynamic modeling and a robust PID controller design process for the wire bonder head assembly. For modeling elements, the system is divided into electrical part, magnetic part, and mechanical part. Each part is modeled using the bond graph method. The PID controller is used for high speed/high accuracy position control of the wire bonder assembly. The Taguchi method is used to obtain the more robust PID gain combinations than conventional one. This study makes use of an L18 array with three parameters varied on three levels. Results of simulations and experimental show that the designed PID controller provides a improved ratio of signal to noise and a reduced sensitivity improved to the conventional PID controller.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.953-956
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• 2017

This paper introduces general applications of vehicle's dynamic pressure information which is estimated during the flight. And a method to estimate the dynamic pressure for a high speed vehicle is suggested to sustain reliability of the flight under a high estimation accuracy of the information. The presented method is straightforward with simple relations of the compressible flow but is a still merited idea employed for the high speed vehicle control scheme with great accuracy.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.199-204
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• 2006

In this paper, we propose an adaptive control algorithm to improve the position accuracy and reduce the nonlinear friction effects for linear motion servo system. Especially, the considered system includes not only the variation of the mass of the mover but also the friction change by the normal force. To adapt to these problems, we designed the controller with the mass estimator and the compensator by observing the variation of normal force. Finally, the numerical simulation results are presented in order to show the effectiveness of the proposed method to improve the position accuracy compared to other control methods.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.707-710
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• 1993

In this paper, we design the high accuracy speed controller of an induction motor by the Fuzzy control algorithms, which recently is invoking the remarkable interest. In order to improve the dynamic resposes such as the steady state error, the reaching tine and the overshoot, the adjustment techniques for optimization of three scale factors are presented. Comparing with conventional PID control, the usefulness of proposed Fuzzy controller will be proved by the simulations.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.76-82
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• 2005

In this paper, the pole placement controller based on the Robust Internal-loop Compensator (RIC) structure, which has inherent structural equivalence to disturbance observer, is proposed to control a linear positioning system. This controller has the advantage to easily select controller gains by using pole placement without loss of that of original RIC structure. The principal is to construct the pole placement controller for a nominal internal model instead of unknown real plant. Using linear motion experiment showed the effectiveness of the proposed controller.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.76-82
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• 1998

In this study, the Ball screw and Servo motor Mechanism is considered as a High Speed Tool Feed System for the machining of a piston of a reciprocating engine. For the machining of a piston, that shapes oval, high speed servo mechanism is needed as a positioning of a cutting tool, and the stroke of tool is 0.1 mm ~ 1 mm. Ball screw and servo motor Mechanism is available very much because this mechanism is used widely in general machine. This Mechanism has been designed with the use of the decrease in mass and partial wear of the ball screw for high speed positioning of tool. Also the periodic learning control method with the inverse transfer function compensation has been applied to the positioning control for the high accuracy positioning of tool. These applications lead the achievement of the machining of a piston with an accuracy of 5${\mu}{\textrm}{m}$ at 2500 rpm in CNC turning.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.747-753
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• 2001

This paper presents a dynamic modeling and a robust PID controller design process for the wire bonder head assembly. For the modeling elements, the system is divided into electrical system, magnetic system, and mechanical system. Each system is modeled by using the bond graph method. The PID controller is used for high speed/high accuracy position control of the wire bonder assembly. The Taguchi method is used to evaluate the more robust PID gain combinations. This study makes use of an L18 array with three parameters varied on three levels. Computer simulations and experimental results show that the designed PID controller provides more improved signal to noise ratio and reduced sensitivity than the conventional PID controller.