• 전기학회논문지
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• 제66권1호
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• pp.66-71
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• 2017

In this paper, we study the robustness of disturbance observer based controller for DC motor in the presence of unmodeled dynamics. It is well known that the robustness property usually becomes weaker as the control gain becomes larger. On the contrary to this expectation, it is shown that the phase margin of DOB controller remains quite a large value even though the time constant of Q-filter becomes smaller. The computer simulation results show that DOB controller is able to stabilize the motor system even in the presence of unmodeled dynamics. On the contrary, the unity-feedback system fails to maintain stability when a high gain feedback is employed for the purpose of achieving better disturbance attenuation performance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.389-392
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• 2001

This paper presents neural load disturbance observer that used to deadbeat load torque observer and regulation of the compensation gain by parameter estimator. As a result, the response of PMSM follows that of the nominal plant. The load torque compensation method is compose of a neural deadbeat observer. To reduce of the noise effect, the post-filter, which is implemented by MA process, is proposed. The parameter compensator with RLSM (recursive least square method) parameter estimator is suggested to increase the performance of the load torque observer and main controller. The proposed estimator is combined with a high performance neural torque observer to resolve the problems. As a result, the proposed control system becomes a robust and precise system against the load torque and the parameter variation. A stability and usefulness, through the verified computer simulation, are shown in this paper.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 추계학술대회 논문집
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• pp.49-52
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• 2002

This paper presents neural load torque observer that used to deadbeat load torque observer and regulation of the compensation gain by parameter estimator. As a result, the response of PMSM follows that of the nominal plant. The load torque compensation method is compose of a neural deadbeat observer. To reduce of the noise effect, the post-filter, which is implemented by MA process, is adopted. The parameter compensator with RLSM (recursive least square method) parameter estimator is adopted to increase the performance of the load torque observer and main controller. The parameter estimator is combined with a high performance neural torque observer to resolve the problems. As a result, the proposed control system becomes a robust and precise system against the load torque and the parameter variation. A stability and usefulness, through the verified computer simulation, are shown in this paper.

• 전기전자학회논문지
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• 제13권1호
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• pp.30-35
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• 2009

입력 상수에 불확실성이 있는 최소위상 비선형시스템에 대해 경로추적 오차가 없는 제어기 설계를 제안하였다. 모델링 불확실성이 존재하는 비선형 시스템에 대해 상태 변수를 예측하기 위해 고 이득 관측기를 사용하였다. 적분형 가변 구조 제어 방식을 이용하여 점근적으로 경로추적오차가 0 되는 새로운 제어기를 제안하여 기존의 경로 추적오차를 감소시켰다. 제어기 설계의 정당성은 폐루프 시스템을 Lyapunov 분석 방법을 통해 보였다. 또한 제어기의 성능을 모의시험을 통해 보였다.

• 전자공학회논문지SC
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• 제40권1호
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• pp.11-18
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• 2003

불확실성이 있는 표준형으로 표현된 단일 입력 단일 출력 비선형 시스템을 고려하였다. 모델링 불확실성을 극복할 수 있고 상태 변수를 예측할 수 있는 고이득 관측기를 이용하였다. 크기가 제한된 출력만을 이용한 슬라이딩 모드 제어기를 이용하여 폐회로를 안정화하였다. 크기가 제한된 출력만을 이용한 제어기를 사용하여 상태변수에 임펄스와 같은 현상이 나타나는 것을 제거하였다. 제안된 방법은 크기가 제한된 제어기 설계를 쉽게 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.233-236
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• 2002

We consider a single-input-single-output nonlinear system which can be represented in a normal form. The nonlinear system has a modeling uncertainties including the input coefficient uncertainties. A high-gain observer is used to estimate the states variables to reject a modeling uncertainty. A globally bounded output feedback integral sliding mode control is proposed to stabilize the closed loop system. The proposed integral sliding mode control can asymptotically stabilize the closed loop system in the it presence of input coefficient uncertainty.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.312-315
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• 2003

This paper deals with robust control problems of linear systems with matched nonlinear uncertainties. In order to handle the uncertainties, a Lyapunov min-max control approach can usually be adopted. By the way, the min-max control input is required to be switched and provokes chattering phenomena which limit the practical implementation. The magnitude of switching control input which cause chattering is dependent on the size of uncertainties. In this paper, it is shown that the magnitude of the min-max control input can be made small using a well-known disturbance observer technique and only considers the disturbance observing errors. The chattering phenomena can be reduced as small as possible by selecting a high diturbance observer gain. The simulations show that the min-max control with a disturbance observer can reduce chattering phenomena much smaller and guarantee much better robust performance rather than the one without a disturbance observer.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.289-297
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• 2014

This paper proposed a novel high performance sensorless control scheme for IPMSM based on an extended nonlinear state observer. The gain-matrix of the observer has been derived by using state linearization method. Steady state errors in estimated rotor position and speed due to parameter inaccuracy have been analyzed, and an equivalent flux error is defined to represent the overall effect of parameter errors contributing to the wrong convergence of the estimated rotor speed as well as rotor position. Then, an online compensation strategy was proposed to limit the estimation errors in rotor position and speed. The effectiveness of the extended nonlinear state observer is validated through simulation and experimental test.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.285-288
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• 2002

This paper presents external load disturbance compensation that used to deadbeat load torque observer and regulation of the compensation gain by parameter estimator As a result, the response of PMSM follows that of the nominal plant. The load torque compensation method is compose of a deadbeat observer To reduce of the noise effect, the post-filter, which is implemented by MA process, is adopted. The parameter compensator with RLSM(recursive least square method) parameter estimator is suggested to increase the performance of the load torque observer and main controller The proposed estimator is combined with a high performance load torque observer to resolve the problems. As a result, the proposed control system becomes a robust and precise system against the load torque and the parameter variation. A stability and usefulness, through the verified computer simulation, are shown in this paper.

• 전력전자학회논문지
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• 제9권3호
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• pp.253-259
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• 2004

본 논문은 BLDC 전동기의 고성능 속도제어를 위하여 외란 초크 관측기를 기반으로 한 속도 제어 방법에 대하여 기술하였다. 강성이 낮은 로봇 팔이나 추적 응용의 경우 시스템의 안정성 측면에서 속도 제어기의 이득 값을 크게 할 수 없다. 따라서 외란 토크 관측기를 이용한 전향 보상 방법을 이용하였다. 본 방법으로 속도 제어기의 이득을 충분히 크게 할 수 없을 때 외란 토크에 대한 속도 응답 특성을 향상시킬 수 있다. 결과적으로, 고성능 분야의 응용을 위한 BLDC 전동기의 속도 제어가 가능하게 된다.