• 대한기계학회논문집
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• 제17권9호
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• pp.2234-2241
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• 1993

The torque variation in drilling process represents the problems of the efficient and stable machining. In order to cope with them, the active control method is adopted to drill the workpiece under the constant cutting torque though the cutting stiffness of the workpiece or the diameter of the drill bit changes. The cutting process is modeled in the geometric viewpoint related with the feed and the number of cutting lips. And the dynamic model is approximated to the first order system for the purpose of control. The adaptive PI control is used in computer simulations and experiments. The results of the study show the validity of the drilling method with torque control.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.33-42
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• 2010

벡터제어를 적용한 유도전동기 드라이브는 고성능 제어를 위하여 산업 적용분야에 광범위하게 사용되고 있다. 그러나 유도전동기의 모델은 비선형이고 복잡하기 때문에 포화, 온도변화, 외란 및 파라미터 변동등에 의해 성능 및 신뢰성이 저하된다. 이러한 가변속 드라이브를 제어하기 위하여 종래의 PI와 같은 제어기들이 일반적으로 사용되어졌다. 이러한 제어기들은 이상적인 벡터제어 상태에서도 광범위한 동작영역에서 양호한 성능을 나타내는데 한계를 가지고 있다. 본 논문은 퍼지제어, 신경회로망, 적응 퍼지제어로 구성된 FNN(Fuzzy-Neural Network)-PI 제어기 기반 자기동조 PI 제어기와 ANN을 이용한 속도추정을 제시한다. FNN-PI, AFC, ANN 제어기를 이용한 제어 알고리즘은 유도전동기 드라이브 시스템에 적용하여 그 결과를 분석하고 제어기의 효용성을 입증한다.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.192-197
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• 2007

This paper presents Hybrid PI controller of IPMSM drive using fuzzy adaptive mechanism(FAM) control. In general, PI controller in computer numerically controlled machine process fixed gain. They may perform well under some operating conditions, but not all. To increase the robustness, fixed gain PI controller, Hybrid PI controller proposes a new method based self tuning PI controller. Hybrid PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

• 한국정보통신학회논문지
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• 제2권1호
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• pp.71-77
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• 1998

본 논문에서는 LMS와 CMA 알고리즘에 의한 적응 배열안테나의 training 원리와 제어방법을 기술하고 수렴특성, 지향성 패턴의 적응성, SINR 및 신호파의 재현 특성을 비교 분석한다. LMS와 CMA 적응 안테나 원리를 적용한 선형 $\lambda$/4 간격 4소자 배열안테나에 $\pi$/4 QPSK 신호파를 인가했을때 정상상태에서 SINR가 각각 13.8［dB］와 12.8［dB］로써 CMA에 비하여 LMS가 우수한 SINR와 빠른 수렴특성을 보였으며 간섭파의 방향에 적응하여 강한 영점을 잘 형성하는 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.506-509
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• 1986

In this paper, the control law for the system that has the variation of moment of inertia is designed. The proposed method is that the control input is obtained by using optimal PI control and partial adaptive control. The partial adaptive control input is adjusted by estimating the variational quantity of moment of inertia. This result gives us significant improvement of tracking ability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.403-405
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• 1999

The model reference adaptive control(MRAC) algorithm is applied to the speed control of an inverter driven permanent magnet brushless do motor MRAC is compared to a standard PI controller. Applying this algorithm has also been proved by simulations that quick speed response without over-shoot could be obtained for the motor system with variable parameters. Simulation results show that the adaptive controller is superior to the PI controller.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권10호
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• pp.697-702
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• 2004

In this paper, we proposed that the problem of controlling induction motor with magnetic saturation, is studied from an input-output feedback linearization with adaptive algorithm. is considered. An adaptive input-output feedback linearizing controller is considered under the assumption of known motor parameters and unknown load torque. In order to achieve the speed regulation with the consideration of improving power efficiency, rotor angular speed and flux amplitude tracking objectives are formulated. Simulation results are provided for illustration.

• Journal of Advanced Marine Engineering and Technology
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• 제3권1호
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• pp.19-31
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• 1979

Recently the adaptive control system, which keeps the control system always optimal by adjusting the control parameters automatically according to the variations of the plant parameters, have become very important in the field of control engineering. The adaptive control systems are usally composed of the plant identification, the decision of the optimal control parameters, and the adjustment of the control parameters. This paper deals with a method of the adaptive control system when PI or PID controller is used in the feed back control system. Its controlled object (the plant) is assumed to be described by the transfer function of $\frac{ke^{-LS}}{1+TS}$ where k, T and L are steady state gain, time constant and pure dead time respectively, and their values are variable in accordance with the change of environmental circumstance. It has been known that a pseudo-random binary signal is quite effective for the measurement of an impulse response of a plant. In adaptive control systems, however, the impulse response itself is not appropriate to determine the control parameters. In this paper, the authors propose a method to estimate directly the parameters of the plant k, T and L by means of the correlation technique using 3 level M-sequence signal as a test signal. The authors also propose a method to determine the optimal parameters of the PI or PID controller in the sense of minimizing the square integral of the control error in the feed back control system, and the values of the optimal parameters are computed numerically for various values of T and L, and the results are examined and compared with those of the conventional methods. Finally the above-mentioned two methods are combined and an algorithm to struct an adaptive control system is suggested. The experiments for the indicial responses by means of both the model of the temperature control system using SCR actuater and the analog simulations have shown good results as expected, and the effectiveness of the proposed method is verified. The M-sequence generator and the time delay circuit, which are manufactured for the experiments, are operated in quite a good condition.

• 조명전기설비학회논문지
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• 제23권2호
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• pp.103-107
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• 2009

PI제어기는 발전기의 전압제어 시스템에 널리 쓰이고 있다. 하지만 발전 시스템의 특성이 연속적으로 변화할 때, 새로운 PI매개변수를 결정하는 것이 쉽지 않다. 이를 해결하기 위하여 본 논문에서는 발전기의 전압제어에 신경망자율 적응 제어를 이용하는 제어 방법을 제안하였다. 전압제어 시스템의 적절한 연속적인 궤환 제어 이득은 델타학습 규칙에 의해서 결정된다. 제안된 제어 방법의 기능은 직류 발전기 전압제어 실험에 의해 확인하였다.

• 한국생산제조학회지
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• 제5권2호
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• pp.63-72
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• 1996

In order to regulate the cutting force at a desired level during peripheral end milling processes a feedrate override Adaptive Control Constraint (ACC) system was developed. The feedrate override function was accomplished through a development of programmable machine controller (PMC) interface technique on the NC controller, Nonlinear model of the cutting process was linearized as an adaptive model with a time varying process parameter. An integral type estimator was introduced for on-line estimation of the cutting process parameter, Zero order hold digital control methodology which uses pole-assignment concept for tuning of PI controllers was applied for the ACC system. Performance of the ACC system wsa confirmed on the vertical machining center equipped with fanuc OMC through a large amount of experiment.