• Journal of Advanced Marine Engineering and Technology
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• 제16권4호
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• pp.50-59
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• 1992

The paper presents a digital speed control approach of induction motor systems by using a digital servo control method and a well-known second order differential equation as model. The basic concept of using the modeling equation stated in the above is induced from the control theory stand point such that we can describe usually the motor system connected by inverter, generator and load etc, just as a mechanical system to be controlled. The concept does not demand us the complicated vector-based modeling equation adopted in the traditional methods for the speed control of induction motor. Futhermore, the proposed speed control system can be treated as a single input and single output system. The effectiveness of the servo control system obtained by the above-mentioned design concept is illustrated by the experimental results in the presence of both step reference changes and load variations. It is observed from the experimental results that the steady state-error of the experimental set up becomes zero after some regulation time and the induction motor system is robust in spite of reference signal changes and load variations.

• 조명전기설비학회논문지
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• 제12권1호
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• pp.111-116
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• 1998

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 변환율에 의해서 결정된다. 신경망 제어기를 이용한 직류서보 전동기의 강인제어는 시abf레이션에 의하여 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제28권5호
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• pp.793-800
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• 2004

The purpose of this study is to develope a servo system with faster and more accurate response. This paper describes a method of approximate reasoning for fuzzy control of servo system based on the decomposition of $\alpha$-level fuzzy sets. We propose that fuzzy logic algorithm is a body from fuzzy inference to defuzzificaion cases where the output variable u directly is generated PWM The effectiveness for robust and faster response of the fuzzy control scheme are 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 is demonstrated successfully.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권1호
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• pp.50-54
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• 2004

Reference trajectory generation plays a key role in the computer control for accurate position control of machine. Generated trajectories must not only describe the desired tool path accurately, but must also have smooth kinetic profiles in order to maintain higher tracking accuracy, and to avoid exciting the natural modes of the mechanical servo control system. To achieve higher accurate position control, a method of limiting accelerating and decelerating speed data of reference trajectories is proposed to draw the path with an assigned accuracy without any complex operations.

• 한국정밀공학회지
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• 제25권2호
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• pp.140-147
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• 2008

This paper describes a Neural Network based PD control scheme for motion control of pneumatic servo cylinder. Pneumatic systems have inherent nonlinearities such as compressibility of air and nonlinear frictions present in cylinder. The conventional linear controller is limited in some applications where the affection of nonlinear factor is dominant. A self-excited oscillation method is applied to derive the dynamic design parameters of linear model. Based on the parameters thus identified, a PD feedback compensator is designed first and then a neural network is incorporated. The experiments of a trajectory tracking control using the proposed control scheme are performed and a significant reduction in tracking error is achieved by comparing with those of a PD control.

• 산업기술연구
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• 제18권
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• pp.289-293
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• 1998

In a independent joint servo control of robots, the performance of the control is influenced greatly by the joint interaction torques including Coriolis and centrifugal forces. These act as disturbance torques to the control system. As the speed of the robot increases, the effect of this disturbance torque increase, and makes the high speed - high precision control more difficult to achieve. In this paper, a solution to the optimal path placement problem is presented that minimizes the joint disturbance torque during a straight line motion. The proposed method is illustrated using computer simulation. The proposed solution method can be applied to the class of robots that are controlled by independent joint servo control, which includes the vast majority of industrial robots.

• 한국해양공학회지
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• 제7권2호
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• pp.79-90
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• 1993

A design method of DPS control algorithm for adpting rotable thruster is introduced by applying servo system design method and the control algorithm is evaluated on the basis of the results of computer simulations performed for a semi-submersible 2-lower hull 8-column type platform. It is observed from the simulation results that position error due to the irregular drifting forces becomes zero after very short regulating time and dynamic positioning system is robust in spite of random disturbance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.137-139
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• 2007

In optical disk drives, a conventional control method in the presence of surface defect is holding the previous tracking control command. It is known that the method has a long settling time. This paper proposes a new control method which reduces the settling time. An optical head generally has coupled dynamics between focusing and tracking servo system. We present how to compensate the coupled dynamics so that reduced settling time is achieved. It is verified by experiments that the proposed method brings an improved performance in the presence of surface defect as well as in the normal operating condition.

• 전력전자학회논문지
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• 제6권1호
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• pp.49-56
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• 2001

본 논문은 신경회로망에 근거한 교류서보전동기의 제어를 위해 새로운 기법을 제안하고자 한다. 일반적인 제어 기법을 사용하는 대선 선경회로망 PID제어가가 교류서보전동기 제어를 위해 이용되었다. 서보시스템에서 널리 이용되는 제어는 PID제어이며, 이는 간단한 구조와 안전성과 신뢰성을 지니고 있다. 그러나 복잡한 사스템에서 문제점을 나타내므로 불확실한 파라미터의 상태에서는 불완전한 동작을 나타내고 있다. 본 논문에서는 PID제어기의 개선된 제어 알고리즘을 제안하여 교류서보전동기의 시스템을 신경회로망제어를 이용한 PID제어기에 의해 구동시켜 단계적인 제어를 시뮬레이션과 실험에 의해서 제안한 제어알고리즘의 타당성을 입증하고자 한다.

• 융합신호처리학회논문지
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• 제2권3호
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• pp.50-56
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• 2001

퍼지제어가 서보시스템에 응용할 때 퍼지정보 시스템의 하드웨어 실현은 고속연산, 짧은 실시간의 제어 및 시스템의 소형 경량화가 요구되고 있다. 본 연구의 목적은 서보시스템에 적용하기 위한 퍼지정보 시스템의 하드웨어를 개발하는 것이다. 본 연구에서는 $\alpha$-레벨 집합의 분해 원리에 기초하여 $\alpha$-컷 양자화에 따라 퍼지추론의 계산 방법을 제안하려다. 이 방법은 퍼지제어기의 아날로그 하드웨어의 구성을 쉽게 행할 수 있다. $\alpha$-컷 양자화에 따른 회지추론 엔진의 출력으로 $\alpha$-컷 양자화에 따른 퍼지추론 영향을 조사하였고 $\alpha$-컷 양자화 4 단계에서 DC 서보시스템의 퍼지제어에 양호한 결과를 얻었다. 제안한 퍼지추론 연산과 중심법에 의한 비퍼지화에서 직접 PWM 조작 신호를 얻는 방법을 나타내었다. 서보계의 실험을 행하여 유용성을 구명하였다.