• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.239-239
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• 2000

This paper present experimental results on temperature trajectory tracking. The benefits of precalculated feedforward input together with PID feedback control are demonstrated by experimental results. To find the feedforward input, the plant (autoregresiive) model is first identified and convex optimization procedure is applied. PID controller is then implemented based on Ziegler-Nickels tuning rule to reduce effects of disturbances and modeling errors. Experimental results show an improvement in slope tracking performance over the fully PID controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.231-236
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• 1997

We propose the hybrid control for the path control of wheeled mobile robot system. To develop the hybrid control of mobile robot, the continuous dynamics of mobile robot are modeled by the switched systems. The abstract model and digital automata for the path control are developed. This hybrid control system has the 3-layered hierachical structure : digital automata as the higher process, mobile robot system as the lower process, and the interface as the interaction process between the continuous dynamics and the discrete dynamics. The control of following the desired-paths with edges are investigated as the applications by the computer simulation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.548-552
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• 1994

The robust compensation controller, which has been proposed by one of the authors and is based on the fundamental principle of making the plant follow the reference model, consists of the reference model and the robust compensator. The reference model is constructed by using the nominal model of the plant and determines the input-output properties of the resultant system. The robust compensator is obtained as a solution of the mixed sensitivity problem in H infinity control theory. Therefore the resultant system is of low sensitivity and robust stability. In the case where uncertainty does not occur in the plant, the plant follows perfectly the reference model. Therefore, in the case where uncertainty occurs in the plant, we propose the system configuration which improves the following accuracy without replacing the 개bust compensator but by identifying, the plant and reconstructing the reference model.

• 제어로봇시스템학회논문지
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• 제6권11호
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• pp.943-954
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• 2000

Fieldbus is the lowest level industrial network in the communication hierarchy of factory automation and distributed process control systems. Data generated from field devices are largely divided into three categories : time-critical, periodic and time-available data. Because these data share one fieldbus medium, it needs a method that allocates these data to the bandwidth-limited fieldbus medium. This paper introduces an implementation method of bandwidth allocation scheme on PROFIBUS. In order to implement bandwidth allocation scheme on PROFIBUS, the following functions need to be supplemented on the FDL(Fieldbus Datalink Layer) protocol: (i) separation of medium bandwidth into periodic and non-periodic intervals, (ii) synchronization of node timers over a local link. In order to examine the validity of bandwidth allocation scheme on PROFIBUS, this paper develops an experimental model of a network system. The results obtained from the experimental model show that the bandwidth allocation scheme satisfies the performance requirement of time-critical, periodic and time-available data.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.556-558
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• 1990

A method of model reduction for reducing a higher order Z-transfer function to its lower order model is developed based on the Block - pulse function. The approach is following : I. Block - pulse function can be applied for Z-transfer function of linear digital system described by high order. II. To determined both the coefficients of the denominator and numerator of reduced model. The proposed method is simple for computation, can preserve the dynamic characteristic of the original model satisfactorily.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.101-106
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• 2003

In the area of tracking control, it is important to design not only the controllers but also the trajectories to which a system has to follow. $5^{th}$ order polynomial is often used with constraints of initial and final states. Smooth ending with possible minimum time is important for many systems because of vibration or jerky motions. Examples are increased with development of technology in smaller, more accurate systems. On the base of a polynomial like trajectory generation method from a paper in ACC2002 and RIC(Robust Internal-loop Compensator) control scheme of Robotics and Bio-mechanics lab. of POSTECH, generalized and expanded polynomial like trajectory generation method is showed.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.223-228
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• 2005

In oprical disk drives, surface defects on a disk distort tracking error signal and disturb a precision tracking control.. A conventional method against disk defect is held the tracking control signal when a defective portion is detected. However, if the defective portion is getting longer, objective lens will get away from following track. In order to keep the postion of spot from following track, the servo system must predict tracking error and control the object lens in the defective portion. A tracking control system for optical disk drives was proposed recently based on both Coprime Factorization(CF) and Zero Phase Erro. Tracking(ZPET) control. The system was proposed for overcome the limit of previously tracking error. But there were no research about the method against the defective portion. This paper proposes a new and simple ZPET construct. as a new method against the defective portion. From experimental results, we have proved that proposed method improves the performance against the defective portion, decreases the uncertainty of a model, and requires less memory than the previously proposed method.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권12호
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• pp.575-583
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• 2001

It is hard to obtain good robust performance and robust stability for uncertain and time-varying system. The robust 2-DOF controller is frequently used to obtain the desired response and the good robustness. Two controllers can be independently designed. Generally, one controller reduces sensitivity to parameter variations, nonlinear effects, and other disturbances. On the other hand, the other controller reduces the error between the desired command and output. In this paper, the various robust perfect MFCs(model-following controllers) combined with TDC(Time Delay Control) are designed, and the imperfect stable MFC combined with TDC and SMC(Sliding Mode Control) is proposed. These controllers are based on the method of designing robust 2-DOF controllers for dynamic system with uncertainty. The performance of the proposed imperfect sable MFC has been evaluated through computer simulations. The simulation results indicate that the proposed controller shows the excellent performance characteristics for an overhead crane with uncertain and time-varying parameters.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.1024-1027
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• 1992

This paper deals with design method of the model following servo system in which optimal regulator probelm is used to design the controllers that make the step/ramp response of the plant be keptclose to a specified ideal step/ramp response of the model. The characteristics of this system is robust in the presence of the specified disturbances or the partameter perturbations of the plant. Especially, by direct feedforward compensator from the reference input the steady state offset of plant output response is excluded and the transient response is improved. Examples are give and the results of the design of the model follwing servo systems are verified by the computer simulation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1068-1072
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• 1991

This paper presents a decentralized model reference adaptive control scheme for an interconnected continuous linear system composed of a number of single-input single-output subsystems in which outgoing interactions pass through the measurement channel and are subject to bounded external disturbance. The scheme can treat the unknown strength of interactions as well as the uncertainty of subsystems.