• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.271-274
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• 2001

The present paper deals with the development of digital contouring controller for multiaxial servosystem. Instead of coordinating the commands to the individual feed drives and implementing closed position loop control for each axis, this work is achieved by the evaluation of a optimal cross-couple compensator aimed specifically at improving contouring accuracy in multi-axial feed drives. The optimal control formulation explicitly includes the contour error in the performance index to be minimized. The contouring control is simulated for straight line. The results show that the proposed controller reduces contouring errors considerably, as compared to the conventional uncoupled control for biaxial systems.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.480-487
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• 2008

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.309-312
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• 2001

본 연구에서는 상류부 교차로에서 발생하는 교차로 막힘 현상으로 인해 진행방향의 녹색시간의 손실이라는 장애가 발생하게되는 상황을 고려하기 위해 진행차선의 정체도를 도입하여 교통 혼잡상황에 적절히 대응할 수 있는 퍼지 교통신호 제어기를 제안한다. 먼저 입출력 공간을 균등 분할한 퍼지 교통신호 제어기를 구성하고, 소속함수 수정알고리즘에 의해 제어기를 수정한다. 실험을 통해 고정식 제어기, 균등 분할한 제어기와 수정된 제어기의 성능을 교차로 지체시간, 진입율과 통과율 면에서 비교하였다. 실험 결과는 수정된 제어기가 다른 제어기들에 비해 향상된 성능을 보여주었다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.369-374
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• 2010

Linear motors are easily affected by load disturbances, force ripples, friction, and parameter variations because there are no mechanical transmissions that can reduce the effects of model uncertainties and external disturbance. In this study, a nonlinear adaptive controller to achieve high-speed/high-accuracy position control of a two-axis linear motor is designed. The operation of this controller is based on a cross-coupling algorithm. Nonlinear effects such as friction and force ripples are estimated and compensated for. An enhanced cross-coupling algorithm is proposed for effectively improving the biaxial contour accuracy while achieving closed-loop stability. The proposed controller is evaluated by performing computer simulations.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.25-37
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• 2014

Recently, our local governments are conducting the introduction of tram system because it is recognized as an effective public transit that can solve a traffic jam in downtown, decreasing public transit share and environmental issues in world wide cities. We developed the Active Priority Control Strategy to efficiently operate a tram in our existing traffic signal system. This study organized the tram system for operating the Active Priority Signal Control, developed the algorithm that calculates a tram-stop dwell time in order to pass the downstream intersection without a stop. The dwell time is determined by arrival time at tram-stop, downstream signal time, and the location of a opposite tram, it can be reduced by choosing the optimal one among Signal Priority Controls. Using the VISSIM and VISVAP model, we conducted a simulation test for the city of Chang-won that it is expected to install a tram system. It showed that a developed signal control strategy is effective to prevent a tram's stop in intersections, to reduce a tram's travel time.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.9
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• pp.103-111
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• 2009

Multi-climbing hydraulic robots are used to lift construction factory (CF) synchronously for applications in the automation of a high-rise building construction. In this study, synchronous motion controller is proposed for the hydraulic robots, whose strategy is not only to make each robot follow the reference path basically by sliding-mode control, but also to synchronize motions of two adjacent cent robots consecutively by cross-coupled control technique. Simulations are performed by using SIMULINK for a system similar to a practical application that includes unbalance in CF and wind disturbance. The results show that the proposed controller significantly reduces synchronous errors, compared to the individual controller for each hydraulic robot.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.206-215
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• 1998

교차로 교통신호제어의 입려정보로 단순히 차량의 대수만으로는 정확한 신호제어를 할 수가 없다. 여기에는 대기차량수, 도로의 길이, 차량의 형태 등을 고려한 도로의 혼잡량이라는 상징적 정보량이 적합하다고 할 수 있다. 그러나 상징적인 정보량은 입력정보인 실제적인 물리량사이에 서로 관련성이 없거나 상충적일 경우, 각 정보간의 선형성과 관련식을 도출하여 상징적인 정보를 얻는다는 것이 어렵다. 본 논문에서는 교통 신호처리에서 사용하는 상징적 정보량의 의미와 필요성을 고찰하여 본 후, 퍼지 이론을 통해 물리적인 교통 정보량을 이용 교통신호제어 상징적인 출력 정량인 교통 혼잡량을 산출하여 교통신호제어에 적용하여 기존의 교통신호제어와 비교하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1003-1006
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• 2002

In machining free-form curves with a machine tool equipped with parallel device, improving contouring accuracy is very important. In this paper, we present contouring control algorithm far parallel machine tool. The relation between the error in Joint space and the error in catesian space is evaluated, and we estimate contouring error vector which efficiently determines the variable gains for the cross coupled control. To show the validity of the algorithm, the contouring control is simulated for free form contour trajectory in cubic parallel machine tool model.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.8
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• pp.65-72
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• 1997

An asymmetrical cross-coupled compensator to improve the contouring performance is proposed. This is a refinement of the structure suggested by Koren. The position loop is closed with a proportional controller as in the uncoupled system. An additional input term proportional to the component of the contour error along the corresponding axis is included. The controller gains are chosen to give an appropriate frequency response and an optimum range for the damping ratio. The effectiveness of the proposed controller is studied by means of digital simulations of the dynamics of the drives and the controller for 4 types of command trajectories: straight line contour, cornering contour, circular contour, elliptic contour. Substantial improvement in contouring performance is obtained for a range of contouring conditions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.106-115
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• 2003

In crossing stereo camera system as a security equipment system, a new algorithm for the tracking method of the moving object and the measurement method of distance of the object from cameras to moving object is proposed. The stereo input images are matched by a pixel for the moving object extraction, then the moving elements obtained from an adaptive threshold's value for an error correction and the moving object area extracted by noise eliminative algorithm. In addition to, the moving object traced by control pan/tilt of cameras using a coordinate value of the moving object, and the measurement method of distance to moving object by using special features of the crossing stereo camera system is proposed. From the experimental results, the proposed algorithm was found to be able to measure of the distance and trace for moving object in a stereo security camera system. The error rate of a distance measurement be existed within 6%. Moreover in implementation the proposed algorithm, the stereo security system, the automatic moving robot system and the stereo remote control system will be applied practical application.