• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.308-309
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• 2016

This paper deals with ship's track keeping methods which is crucial part of automatic navigation control systems. In this paper, we mainly discuss the performance of different guidance methods including way point guidance, enclosure-based steering guidance and lookahead-based steering guidance system. As a controller, a PID control system is employed to control ship's rudder angle during track-keeping. Finally, the performance of three methods are discussed through some simulation results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1874-1882
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• 2015

In this paper, robust backstepping controller for IPMSM is proposed based on the PID integral sliding mode control. Because of the unmatching condition of load, the sliding mode control is difficult to be used for IPMSM without backstepping. However, the backstepping control has the difficulty of deriving error dynamics which is derived by differentiating the previous input. This difficulty is avoided by adopting PID as a nominal controller for the integral sliding mode control. The proposed controller can be achieved easily by adding integral sliding controller to the conventional PID controller.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.9
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• pp.877-882
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• 1991

The idea of expert control is to incoporate a rule based expert system in a feedback control system. In this paper, We present some heuristic rules about input regulation and supervision and turning for D.C. servo motor speed control. The expert auto-turning PID Controller which Heuristic rules are used as an element of the feedback control system is implemented with the numerical algorithms and Heuristic logics. The robust and accurate control function is confirmed by computer simulation..

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.279-284
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• 2014

This paper proposes a optimum design method for the Fuzzy PID controller of magnetic levitation-based Rail-Guided Vehicle(RGV). Since an attraction type levitation system is intrinsically unstable, it is difficult to completely satisfy the desired performance through the methods designed by conventional controllers. In the paper, the Fuzzy PID controller with fixed parameters are applied and then the optimum parameters of fuzzy PID controller are selected by genetic algorithm. For the fitness function of genetic algorithm, the performance index of PID controller is used. To verify the performance of the proposed method, we used Matlab/simulink model of Maglev and compared the proposed method with the performance of PID controller. The simulation results show that the proposed method is more effective than conventional PID controller.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.10
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• pp.867-872
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• 2013

Many practical processes in industry have nonlinearities of some forms. One commonly encountered form is actuator saturation which can cause a detrimental effect known as integrator windup. Therefore, a strategy of attenuating the effects of integrator windup is required to guarantee the stability and performance of the overall control system. In this paper, optimal tuning of a PID (Proportional-Integral-Derivative) controller with an anti-windup scheme is presented to enhance the tracking performance of the PID control system in the presence of the actuator saturation. First, we investigate effective anti-windup schemes. Then, the parameters of both the PID controller and the anti-windup scheme are optimally tuned by an EA (Evolutionary Algorithm) such as the IAE (Integral of Absolute Error) is minimized. A set of simulation works on two high-order processes demonstrates the benefit of the proposed method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.111-116
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• 2004

In this paper, parameters of a given DC motor system are estimated using the model adjustment technique and the real coded genetic algorithm(RCGA) technique. A number of tuning methods, based on experience and experiment, such as Ziegler-Nichols, Cohen-Coon, IMC, L-ITAE Method have been proposed to obtain parameters for the PID controller. This paper proposes estimating parameters of PID controller using RCGA. The performance of the proposed algorithm is demonstrated through simulations and experiences.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.323-326
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• 2003

본 논문에서는 PID 제어기를 이용해 외란제거를 함은 물론 최적 제어가 될 수 있는 파라메터를 유전자 알고리즘을 통해 구하는 방법을 제안하였다. 외란제거를 위해 $H_\infty$-norm을 응용하여 제어시스템의 외란 제거 조건들을 제시하고 이 조건들을 만족하는 PID 제어기를 설계하였다. 설계된 PID제어기의 최적 파라메터를 구하기 위해 유전자 알고리즘을 이용하였고 최적 파라메터를 평가하기 위하여 ITSE(Integral of time weighted squared error)성능지수를 이용하였다. 위의 설계 기법들을 서보모터의 제어에 적용하여 만족할 만한 결과를 얻었다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.10
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• pp.52-58
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• 1997

In this paper, we consider methods of robust stabilization of the interval plant with a PID controller. Suppose that we know apriori a sign of the coefficients of the numerator of the PID controller. Under this condition, it sufficies to make eight polynomials stable for robust stabilization of the interval plant with a minimum phase PID controller. In addition, with a nonminimum phase PID controller, it suffices to make different eight polynomials stable. Especially, with the nonminimum phase PID controller it is shown that stabilization of eight plants is necessary and sufficient for robust stabilization of the interval plants.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1905-1919
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• 2000

The main motivation of this research is to develop an intelligent control strategy for Activated Sludge Process (ASP). ASP is a complex and nonlinear dynamic system because of the characteristic of wastewater, the change in influent flow rate, weather conditions, and etc. The mathematical model of ASP also includes uncertainties which are ignored or not considered by process engineer or controller designer. The ASP is generally controlled by a PID controller that consists of fixed proportional, integral, and derivative gain values. The PID gains are adjusted by the expert who has much experience in the ASP. The ASP model based on $Matlab^{(R)}5.3/Simulink^{(R)}3.0$ is developed in this paper. The performance of the model is tested by IWA(International Water Association) and COST(European Cooperation in the field of Scientific and Technical Research) data that include steady-state results during 14 days. The advantage of the developed model is that the user can easily modify or change the controller by the help of the graphical user interface. The ASP model as a typical nonlinear system can be used to simulate and test the proposed controller for an educational purpose. Various control methods are applied to the ASP model and the control results are compared to apply the proposed intelligent control strategy to a real ASP. Three control methods are designed and tested: conventional PID controller, fuzzy logic control approach to modify setpoints, and fuzzy-PID control method. The proposed setpoints changer based on the fuzzy logic shows a better performance and robustness under disturbances. The objective function can be defined and included in the proposed control strategy to improve the effluent water quality and to reduce the operating cost in a real ASP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.655-662
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• 2016

Accurate stopping control is important for trains, especially now that many train stations are equipped with platform screen doors. Various algorithms have been proposed for accurate stopping control. However, most metro trains in South Korea use classic control algorithms such as PID control because other algorithms are too complex to realize. PID control has merits of simple structure and operation. However, PID control sometimes fails, and much time is needed to find the proper coefficients due to the long control period and the brake delay. We propose a control algorithm that uses a Kalman filter. The Kalman filter estimates the states at the time when braking starts. Then, a suitable control input is derived for proper control. System modeling and a computer simulation were performed with consideration of the brake properties and the period of the control system. The superiority of the proposed control algorithm is shown by analyzing stop errors.