• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 춘계학술대회 학술발표 논문집
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• pp.228-231
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• 2000

A hybrid fuzzy controller by means of the genetic algorithms is presented. The control input for the system in the HFC is a convex combination of the FLC's output in transient state and PlD's output in steady state by a fuzzy variable. The HFC combined a PID controller with a fuzzy controller concurrently produces the better output performance than any other controller. A auto-tuning algorithms is presented to automatically improve the performance of hybrid fuzzy controller using genetic algorithms. The algorithms estimates automatical Iy the optimal values of scaling factors, PID parameters and membership function parameters of fuzzy control rules. Especially, in order to auto-tune scaling factors and PID parameters of HFC using GA three kinds of estimation modes are effectively utilized. The HFCs are applied to the second process with time-delay. Computer simulations are conducted at step input and the performances of systems are evaluated and also discussed in ITAE(Integral of the Time multiplied by the Absolute value of Error ) and other ways.

• 수산해양기술연구
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• 제59권2호
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• pp.145-154
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• 2023

In this study, to control the heading angle of a ship, which is constantly subjected to various internal and external disturbances during the voyage, an LADRC (linear active disturbance rejection control) design that focuses more on improving the disturbance removal performance was proposed. The speed rate of change of the ship's heading angle due to the turn of the rudder angle was selected as a significant factor, and the nonlinear model of the ship's maneuvering equation, including the steering gear, was treated as a total disturbance. It is the similar process with an LADRC design for the first-order transfer function model. At this time, the gains of the controller included in LADRC and the gains of the extended state observer were tuned to RCGAs (real-coded genetic algorithms) to minimize the integral time-weighted absolute error as an evaluation function. The simulation was performed by applying the proposed GA-LADRC controller to the heading angle control of the Mariner class vessel. In particular, it was confirmed that the proposed controller satisfactorily maintains and follows the set course even when the disturbances such as nonlinearity, modelling error, uncertainty and noise of the measurement sensor are considered.

• 제어로봇시스템학회논문지
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• 제21권5호
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• pp.482-489
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• 2015

CSTR (Continuous Stirred Tank Reactor) which plays a key role in the chemical plants exhibits highly nonlinear behavior as well as time-varying behavior during operation. The control of CSTRs in the whole operating range has been a challenging problem to control engineers. So, a variety of feedback control forms and their tuning methods have been implemented to guarantee the satisfactory performance. This paper presents a scheme of designing a nonlinear PID controller incorporating with a GA (Genetic Algorithm) for the temperature control of a CSTR. The gains of the NPID controller are composed of easily implementable nonlinear functions based on the error and/or the error rate and its parameters are tuned using a GA by minimizing the ITAE (Integral of Absolute Error). Simulation works for reference tracking and disturbance rejecting performances and robustness to parameter changes show the feasibility of the proposed method.

• 제어로봇시스템학회논문지
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• 제15권6호
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• pp.581-589
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• 2009

In a two-inertia motor system with flexible shaft, a torsional vibration is often generated as a quick speed response is required. This vibration makes it difficult to achieve a quick response of speed and disturbance rejection. The objective of this paper is to provide a systematic analysis and design of the three kinds of speed controllers such as I-P, I-PD, and state feedback control by using the weighted ITAE performance index. Some simulation and experiment results verify the effectiveness of the proposed design.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.815-817
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• 1999

In the two-mass system driving a load through a flexible shaft or transmission system, a shaft torsional vibration is often generated. In this case, it's difficult to control only by conventional PI controller. To solve this problem. the two-mass speed control system with PID controller is designed by using pole assignment method, and an optimum PID parameters are derived by evaluating ITAE(Integral of time multiplied by the absolute error) performance index. Simulation results show the validity of the proposed PID controller and this controller is compared with the conventional PID controller.

• Journal of Advanced Marine Engineering and Technology
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• 제6권2호
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• pp.42-50
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• 1982

The controller, generally, is to be designed to optimize the system in somesence subject to some constraints. In this paper the method to determine the optimal parameters of the PI controller in the unity feed back control system is proposed. Here the sence of the optimal is to minimize the integral of the squared error under the constraints that the maximum absolute value of control input, maximum overshoot, rise time, etc., should be smaller than the pre-given values. In the analysis the traditional method and the state variable method are combined in order to reduce the computational procedures required in the design of PI controller. Therefore, the procedure proposed in the paper is usefully applicable to the controller system with a general second-order plant. Finally, the indicial response curves generated at the optimal state are compared with those of non-optimal state and the effectiveness of this method is assertained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2114-2116
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• 2002

본 논문은 개선된 Complex 방법을 이용한 하이브리드 퍼지 PID 제어기의 최적 자동동조 알고리즘을 제안한다. 제어응답은 퍼지제어기의 환산계수 값에 의해 여러 종류, 여러 형태로 변화하기 때문에 해당하는 제어계의 평가 기준을 만족하도록 제어 파라미터 값을 정하는 것이 중요하다. PID 파라미터 조정법에는 많은 방법이 제안되어 왔었다. 대표적인 예로서 Ziegler-Nichols, Cohen-Coon, Chien-Hrones-Reswick(CHR) 등에 의해 제안된 방법들이 있다. 본 논문에서는 개선된 Complex 방법을 이용한 강력한 자동동조 알고리즘이 하이브리드 퍼지 PID 제어기의 성능을 자동적으로 개선하기 위해 사용된다. 이 알고리즘은 하이브리드 퍼지 PID 파라미터와 환산계수를 제어출력 변화율과 제한조건에 따라 자동으로 추정한다. 지연시간을 갖는 1계, 2계 공정에 적용하고. 공정출력 기준치는 단위 입력으로 한다. 제어 결과의 성능평가를 위해 ITAE(Integral of Time multiplied by the Absolute value of Error)가 사용되며, 또한 제어기의 오버슈트도 토의된다.

• 전기학회논문지
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• 제57권8호
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• pp.1447-1453
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• 2008

In this paper, we proposed to improve performance of the design of a cascade controller with the smith-predictor structure. The parameters of controller in the inner loop are determined to minimize the integral of time multiplied by the absolute value of error (ITAE) value of performance Index. The controller of outer loop and parameters of Smith-Predictor can be obtain using reduction model. The model reduction is considered that it is the transient response and the steady-state response through the use of nyquist curve. Simulation examples are given to show the better performance of the proposed method than conventional methods.

• Advances in Energy Research
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• 제8권3호
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• pp.145-153
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• 2022

Recent concerns about rising fuel prices and greenhouse gas emissions have focused attention on alternative energy sources, particularly in the transport sector. Transportation consumes 40% of overall fuel usage. As a result, a growing majority of researches on Electric Vehicles (EVs) and their Energy Management Systems (EMS) have been done. In order to enhance the performance and to meet the needs of drivers, more information regarding the EMS is needed. A new Energy Management System is proposed using a FOPID controller. To put the concept into practice, state equations are utilised. The fifth-order state-space model under study is a linked model with several inputs and outputs and the transfer matrices are calculated for decoupling the system. Utilizing these transfer matrices to decouple the system and FOPID controller is used to tune the system. The tuned parameters are minimized using a Particle Swarm Optimization (PSO) approach with Integral Time Absolute Error (ITAE) as the goal. When the suggested FOPID system's results are compared to those of PID-controlled systems, a sizable improvement is observed, which is explained by the results.

• 동력기계공학회지
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• 제11권3호
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• pp.66-72
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• 2007

This study proposed new method to decide the reference model necessary for design PID controller. In generally, control design problems using the reference model have the following two factors. One factor is that numerical model of the controlled system can be obtained extremely, and the other is that specification for the closed-loop dynamic performance is pure moderate. Therefore, the control design procedure is essentially based on the partial reference model matching which offers a reasonable method to simplify the design and the controller configuration under the controlled system uncertainty. ITAE(Integral of time-multiplied absolute error) performance index and Kitamori method etc. which were used a reference model method had a limit to settling time and rising time of reference model that it arrived to steady state response according to the controlled system. On this study, if it only knew peak time of overshoot and settling time by measurement signal of the controlled system, it can be made the reference model easily. We proposed new method to improve performance index of the reference model superior to existing reference model index and illustrate the numerical simulation results to show the effectiveness of proposed control method design.