• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.12
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• pp.894-902
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• 1988

In this paper, a method for the design of robust adaptive controller using the heuristic rules of industrial engineers is presented. This scheme works on the basis of heuristic rules and includes a supervisor, a system identifier and a detuner. The supervisor detects onsetting instability based on the analysis of the amplitude and the trend of error signal, also selects running controllers. Upon detecting instability, the controller is switched to a PID algorithm and run recursively until stability is restored. Simultaneously, new input / output data is gathered and the system identifier runs to get critical sensitivity (kc) and critical period(tc). Based on the new values(kc, tc), a GPC controller is redesigned and normal GPC is finally run. The algorithm described in this paper belongs to the supervised adaptive control category with a limited use of heuristic rules. Finally, we show the robust of this scheme by simulated example.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.397-400
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• 1991

This paper presents a cartesian space decentralized adaptive controller design for the end effector of the robot manipulator to track the given desired trajectory in the cartesian coordinate. By the cartesian based control scheme, the task related high level motion command is directly executed without solving the complex inverse kinematic equations. The controller does not require the complex manipulator dynamic model, and hence it is computationally very efficient. Each degree of freedom of the end effector on the cartesian space is controlled by a PID feedback controller and a velocity acceleration feed forward conpensation part. Simulation results for a two-link direct drive manipulator conform that the present cartesian based decentralized scheme is feasible.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.691-695
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• 1998

Most of systems has nonlinearity . And also accurate modelings of these uncertain nonlinear systems are very difficult. In this paper, a fuzzy modeling technique for the stabilization control of an IP(inverted pendulum) system with nonlinearity was proposed. The fuzzy modeling was acquired on the basis of ANFIS(Adaptive Neuro Fuzzy Infernce System) which could learn using a series of input-output data pairs. Simulation results showed its superiority to the PID controller. We believe that its applicability can be extended to the other nonlinear systems.

• Proceedings of the KIEE Conference
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• summer
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• pp.956-958
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• 2004

이 논문에서, 우리는 PMLSM(permanent magnet linear synchronous motor) 시스템에서 발생하는 detent force의 ripple 저감을 위한 진동보상 모델과 제안한 구조에 대한 제어기 설계 방법을 제시한다. 본 논문에서 고려되어진 제어기는 feedforward 보상기, PID feedback 보상기, 그리고 adaptive feedforward 보상기의 세 부분으로 구성된 제어기를 사용한다. 특히, PMLSM의 위치 정밀성 향상에 관한 연구를 위한 정밀 위치 제어의 문제는 PM으로 인해 발생하는 detent force이며, 이를 해결하기 위해 출력신호를 웨이블릿 변환하여 추출 후 이를 보상하였다.

• Journal of Electrical Engineering and Technology
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• v.8 no.2
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• pp.252-261
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• 2013

In this paper, a nonlinear adaptive damping controller based on radial basis function neural network (RBFNN), which can infinitely approximate to nonlinear system, is proposed for thyristor controlled series capacitor (TCSC). The proposed TCSC adaptive damping controller can not only have the characteristics of the conventional PID, but adjust the parameters of PID controller online using identified Jacobian information from RBFNN. Hence, it has strong adaptability to the variation of the system operating condition. The effectiveness of the proposed controller is tested on a two-machine five-bus power system and a four-machine two-area power system under different operating conditions in comparison with the lead-lag damping controller tuned by evolutionary algorithm (EA). Simulation results show that the proposed damping controller achieves good robust performance for damping the low frequency oscillations under different operating conditions and is superior to the lead-lag damping controller tuned by EA.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.333-338
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• 2002

자기베어링의 회전정밀도에 영향을 미치는 인자로 PWM 전력증폭기, 위치 센서 등과 같은 자기베어링 구성 장치의 동특성 및 정밀도, 시스템의 정확한 모델링, 제어기법, 런아웃 등이 있다. 본 연구에서는 능동 자기베어링을 제어하기 위해 자기베어링의 PWM 전력증폭기와 회전축을 모델링하고 이를 바탕으로 능동 자기베어링 제어를 위한 PID 제어기를 구성하였으며, 변위 센서의 부착위치 및 회전축의 진원도의 영향으로 발생하는 주기적인 런아웃 요소를 첨가하여 런아웃의 영향을 확인하였으며, 런아웃 (Runout)에 의해 발생하는 에러(Error)를 효과적으로 제어하여 자기베어링의 제어 정밀도를 향상시키기 위한 방법으로 기본적인 PID 제어기에 최소평균자승(Least Mean Square, LMS) 알고리즘을 적용한 적응 피드포워드 제어기를 구성하여 자기베어링의 능동 제어에서 발생하는 주기적인 런아웃을 효과적으로 제어할 수 있음을 MATLAB을 통한 시뮬레이션을 통해 확인하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.405-413
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• 2006

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it an other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.55-64
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• 2007

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.351-351
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• 2000

Since the heat exchange system, such as the boiler of power plant, gas turbine, and radiator require an application of intelligent control system for a high rate heat efficiency and the efficiency of these systems is depended on the control methods it is important for operator to understand control system of these systems and intelligent control technologies. In order to properly apply control equipment and intelligent technology to these process control systems, it is necessary to understand fuzzy, neural network, genetics, and immune as well as the basic aspects and operation principle of the process that relate control, interrelationships of the process characteristics, and the dynamics that are involved. Generally, since PID controllers are used in these systems it is difficult far engineer to understand both the complex dynamics and the intelligent control method. In this paper, we design an effective experimental system for the intelligent control education and analyze its characteristics through experimental system and each intelligent method to study how they can learn intelligent control system by experiments.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.4
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• pp.320-328
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• 1994

In 1980 s to 1990 s the marine propulsion diesel engines have been developed into lower speed and longer stroke for the enegy saving (small S.F.O.C). As these new trends the conventional mechanical-hydraulic governors were not adapted to the new requirements and the digital governors have been adopted in the marine use. The digital governors usually use the control algorithms such as the PID control, optimal control, adaptive control and etc. While the engine has delay time and parameter variations these control algorithms have difficulty in considering the stability and the robustness for the model uncertainty. In this study, the $H_{\infty}$ controller design method are applied in order to design the feedback controller K(s) to the speed control of the low speed marine diesel engine, and the two-degree-of-freedom control system is constituted with $H_{\infty}$controller. By comparison of responses of the two-degree-of-freedom control system under the delay time and parameter variations is confirmed.