• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.1-5
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• 2010

We propose an algorithm which can classify the system should use a PI controller, which have a weak high frequency attenuation characteristics near the critical frequency. To classify the system, we use a time delay element to calculate a gain attenuation rate near the critical frequency. The proposed algorithm also can design PI controller with the given magnitude margin and phase margin specification. The proposed algorithm uses time delay element and saturation function to identify the one point information in frequency domain. We justify the proposed algorithm via the simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.403-410
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• 1999

A conventional PID controller has poor performance when it applied to systems with unknown deadzones. To solve this problem, this paper proposes PID controller using two layered-fuzzy logic. The structure of controller is reconstructed with fuzzy compensator and fuzzy tuner on the conventional PID controller. Our proposed control scheme shows superior transient and steady-state performance compared to conventional PID controller. The scheme is robust to variations in deadzone nonlinearities as well as the steady-state gain of the plant. The performance of the developed controller is verified through simulation.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.826-827
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• 2015

본 논문은 비선형적인 파라미터 특성을 갖는 Switched Reluctance Motor(SRM)의 강인제어를 위한 보다 정확하고 안정적인 전류제어 방법에 대해 설명한다. 기존의 전류제어 방법에는 이득설정이 간편한 PI 제어기를 이용한 방법이 주로 사용되어왔다. 본 논문에서는 자기동조 퍼지 제어기를 이용한 방법과 Dead-Beat 제어기를 이용한 방법을 통하여 파라미터의 변화에도 안정적인 전류제어가 가능한 것을 보였고 PI 전류 제어기와 자기동조 퍼지 전류 제어기, 그리고 Dead-Beat 전류 제어기를 각각 적용한 전류제어 SRM 드라이브의 Matlab/Simulink 시뮬레이션 결과를 통하여 제어성능을 비교분석하였다.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.66-68
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• 2004

PID제어기를 플랜트 파라미터를 이용하여 구성하는 IMC-PID제어에 대해 연구한다. 특히 변하는 플랜트에 대해서는 자기동조(ST, Self-Tuning)를 사용하여 시스템을 식별하여 활용한다. 특히 실시간으로 개루프의 위상여유 및 이득여유를 모니터링하여 정해진 구역을 벗어나게 되면 식별된 시스템파라미터를 이용하여 IMC-PID제어기를 구성한다. 또 시간영역 지표로 과도한 오차가 발생하는 경우에도 제어기를 갱신함으로서 전체적으로 보면 견실 PID제어기 형태를 갖게 한다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.11-16
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• 2005

This paper proposed a new IMC-PID controller design method using the loop shaping method. By the application of the loop shaping method for IMC-PID controller which has only one design parameter and guarantees internal stability, we can not only consider such design specifications as gain margin, phases margin, and sensitivity functions but also obtain the loop gain by setting up the relationships between design specifications and design parameters. A systematic method to select design parameters of IMC-PID controller in order to meet the design specifications is suggested and its effectiveness is examined by the case study and analysis.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.3
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• pp.60-65
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• 2000

We propose a new method to deal with the optimal gain self-tuning of the PID controller which is used to industrial process control in various fields. First of all, in this method, first order delay system which was modeled from the unit step response of the system is Pade-approximated, then initial values are determined by the Ziegler-Nickels method. Finally, we can find the parameters of Pm controller so as to maximize the fuzzy inferencl function which includes the maximum overshoot, damping ratio, rising time and settling time. The proposed method also shows good adaptability for variations in characteristics and dead time of the system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.1
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• pp.1-10
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• 2003

This paper is concerned with the fuzzy control scheme and PID controller for the vibration suppression control of a cantilever beam equipped with a laser sensor and an electromagnetic actuator. The PID controller is being widely used in industrial applications. However, it is difficult to determine the appropriate PID gains in nonlinear systems and systems with time variant characteristic and so on. In this paper, we design the fuzzy based PID controller of which output gains are adjusted automatically and the designed controller is applied to active vibration control of a cantilever beam using electromagnetic actuator with strong nonlinearity. The tuning PID parameters of proposed controller are determined by using Fuzzy algorithm. Effectiveness and performance of the designed controller are verified by both simulation and experiment results. Experimental results demonstrate that better control performance can be achieved in comparison with the PID cotroller.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2218-2220
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• 2003

현대 산업현장에서 80%이상 사용되는 PID(proportional integral derivative) 제어기는 제어성, 적응성, 제어이득 조정 등의 특정이 있어나 제어 대상에 대한 PID 제어 계수를 경험적 방법인 수동으로 동조해야하는 문제점이 있다. 이를 개선하기 위해 본 논문에서 PID제어기의 최적 자동동조를 위한 릴레이 동조 방법을 제안한다. 기존의 한계감도법과 과도응답 법으로 초기계수를 결정하는 방법보다 유연성과 적용성이 높고, 이를 마이크로프로세서(DSP : TMS-320C32)에 적용하여 소프트웨어적으로 릴레이의 기능이 이루어지도록 설계했다. 이는 Ziegler-Nichols 계수조정법이 갖는 적용대상의 제약성을 극복한 방법이며, 릴레이에 의해 출력을 강제 진동시키고 출력의 진폭과 주기를 이용하여 PID 계수를 조정하고, 또 상대안정성의 척도인 위상여유를 고려하므로 시스템의 상대안정성과 견실성을 향상시킬 수 있음을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.184-187
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• 1996

In this paper, an algorithm for tuning gains of a PID controller is proposed. The proposed algorithm is composed of two stages. The first is a stage for Lyapunov function-based initial stabilization of an overall system and rough tuning gains of the PID controller. The other is that for fine tuning gains of the PID controller. All tunings are performed by using the well-known fuzzy logic-based tuner. The computer simulations are performed to show the validity of the proposed algorithm and results are presented.

• Journal of IKEEE
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• v.6 no.2 s.11
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• pp.128-135
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• 2002

We use the saturation nonlinear feedback element to generate self-oscillation in order to find an ultimate gain and period of linear plant. The use of saturation nonlinear feedback element can improve accuracy of an ultimate gain and period of unknown linear plant. An ultimate gain and period of linear plant can be used to tune a PID controller parameters. It is possible that an asymmetric oscillation can be occurred under the special circumstances such as with static load disturbance. We analyze an asymmetric self-oscillation. As the results of an analysis, we propose a method to find an ultimate gain and period of linear Plant under the asymmetric self-oscillation.