• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.242-244
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• 1992

Conventionally in the industrial control, PlD controller has been used because of its robustness, and nonlinear characteristic of a system under control. Although the PlD controller produce suitable parameter of the each system and also variable of PlD controller should be changed according to environment, disturbance, load. In this paper, the convergence and learning accuracy of the back-propagation(BP) method in neural network are investigated by analyzing the reason for decelerating the convergence of BP method. and examining the rapid deceleration of the convergence when the learning is executed on the part of sigmoid activation function with the very small first derivative. The modified logistic activation function it proposed by defining the convergence factor based on the analysis and applied to the position and speed control of a DC-servo motor. This paper revealed for experimental, a neural network and a PD controller combined off-line system using developed the position and speed characteristics of a DC-servo motor.

• 한국산학기술학회논문지
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• 제10권8호
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• pp.1993-1997
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• 2009

산업 자동화의 고정밀도에 따라 직류서보 전동기는 강인제어가 요구되고 있다. 하지만 PID 제어기를 갖는 전동기 제어 시스템이 부하 외란의 영향을 받게되면 제어 시스템의 강인제어는 어렵게 된다. 이에 대한 보완적인 한 방법으로 본 논문에서는 전동기 제어시스템을 위한 PID-신경망 복합형 제어기법을 제시하였다. 신경망 제어기의 출력은 부하 외란 인가시에 발생되는 오차와 오차 변화율에 의해서 결정된다. 신경망 제어기를 이용한 직류서보 전동기의 강인제어는 시뮬레이션에 의하여 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.662-665
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• 2001

As the fuzzy control is applied to servo system the hardware implementation of the fuzzy information systems requires the high speed operations, short real time control and the small size systems. The aims of this study is to develop hardware of the fuzzy information systems to be apply to servo system. In this paper, we propose a calculation method of approximate reasoning for fuzzy control based on $\alpha$-level set decomposition of fuzzy sets by quantize $\alpha$-cuts. This method can be easily implemented with analog hardware. The influence of quantization levels of $\alpha$-cuts on output from fuzzy inference engine is investigated. It is concluded that 4 quantization levels give sufficient result for fuzzy control performance of do servo system. It examined useful with experiment for dc servo system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.127-129
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• 2008

This paper describes a method of approximate reasoning for fuzzy control of servo system, based on decomposition of -level fuzzy sets. It is propose that logic circuits for fuzzy PI+PD are a body from fuzzy inference to defuzzificaion in cases where the output variable u directly is generated PWM. The effectiveness for robust and faster response of the fuzzy control scheme is verified for a variable parameter by comparison with a PID control and fuzzy control. A position control of DC servo system with a fuzzy logic controller successfully demonstrated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.129-130
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• 2007

Self servo track writing(SSTW)은 servo track writer(STW)를 이용하지 않고 hard disk drive의 내부 VCM을 이용하여 servo track을 기록하는 방식이다. SSTW는 이전 servo track을 상대적인 reference로 하여 기록하게 되므로 초기에 발생된 error와 외부의 disturbance의 영향으로 error는 급속하게 증가된다. 이것을 radial error propagation 이라 한다. 본 논문에서는 radial error propagation을 억제하기 위한 correction signal을 설계하고 servo writing 과정에서 발생하는 disturbance의 영향을 제거하기 위하여 disturbance observer(DOB)를 add-on type으로 구성하여 tracking 제어기를 설계하였다. 또한 DOB를 적용한 경우와 유사한 gain margin, phase margin과 sensitivity function을 갖는 제어기를 설계하여 그 성능을 비교하였다. 제안된 방식은 radial error propagation을 억제 하였을 뿐만 아니라 disturbance의 최소화하여 쓰여진 track의 DC track spacing과 AC track Squeeze가 개선된 것을 모의실험을 통하여 검증하였다.

• 전자공학회논문지B
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• 제30B권9호
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• pp.122-132
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• 1993

In this paper, a self tuning control algorithm is proposed for the high performance drive of DC servo motor, which is adequate to the servo system having frequent load variation. In order to realization of the algorithm, the control system is developed using a fixed point high speed digital signal processor. TMS320C25. Control algorithm is composed of two parts. One is estimation law part using recursive least mean square method, the other is control law part using minimum variance control method. For the purpose of easiness of applying adaptive algorithm, developed control system is based o PC-DSP structure which can develop, debug programs and monitor the dynamic behaviors,etc. Through computer simulation and experimental results, it was verified that proposed control system could estimate system parameters and was robust to the variation of the load and as a result, was adequate to the servo motor drives.

• Journal of Advanced Marine Engineering and Technology
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• 제33권8호
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• pp.1246-1253
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• 2009

논문은 서보계에 퍼지제어를 위하여 퍼지 $\alpha$-레벨 집합 분해에 기초하한 퍼지추론 계산식이 유도 되었다. 유도한 계산식에 기초한 PI+PD형 퍼지 제어기는 퍼지 추론에서 비퍼지화까지 일체형으로 구성되어 PWM 조작량 u를 발생하는 퍼지 로직 회로가 제안되었다. 시뮬레이션에 의해 퍼지추론의 $\alpha$-레벨의 효과가 검토되어 직류 서보계의 퍼지제어에서 $\alpha$-레벨 양자화수는 4단계이면 충분한 것을 알 수 있다. 제안한 하드웨어 퍼지제어기는 직류 서보계의 위치제어에 시뮬레이션과 실험이 성공적으로 행할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.414-417
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• 1988

This paper presents a study on the operation of a digitally controlled DC servo motor drive at low speed region. Two schemes aiming to improve the transient behavior of the speed control system are considered. The first scheme is the current positive feedback scheme to reduce the sensitivity of the system with respect to the load torque variations. The second one is the speed observer based on a motor model. Finally, the two schemes are studied by simulation and then verified experimetally using a prototype DC motor drive.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.53-55
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• 1988

The application of Sliding Mode Control for inproving the dynamic response of a Multi-Phase-Bipolar (MPB) Brushless DC motor based position Brushless DC motor system is presented. Sliding Mode Control gives fast dynamic response with no overshoot and zero steady state error. It has the important feature of bins highly robust. A design procedure is outlined for the Sliding Mode Controller for a MPB Brushless DC motor. Digital computer simulation of the overall position control system is carried out using a time domain model in the d-q reference frame.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 학술대회 논문집 전문대학교육위원
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• pp.141-145
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• 2001

In this paper, model reference PID genetic controller was proposed in order to overcome the difficulty of reflecting control performance required in the overall control system and defects of the adaptation performance in the PID genetic controller. The proposed controller comprised Inner feedback loop consisting of the PID controller and plant, and outer loop consisting of an genetic algorithm which was designed for tuning a parameter of the controller. A reference model was used for design criteria of a PID controller which characterizes and quantizes the control performance required in the overall control system. Tuning parameter of the controller is performed by the genetic algorithm. The performance of proposed algorithm was verified through experiment for the DC servo motor.