• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제51권3호
• /
• pp.116-124
• /
• 2002

Design and analysis of disturbance observer-based deadbeat control fur single-phase inverter applications are comprehensively presented in this paper. Load current can be estimated by disturbance observer, which is basically structured with the first order equation in this case and is regarded as a relatively simple method in comparison with conventional full-order Luenberger observer. Also, an inherent one-step delay problem appeared in the deadbeat control method is overcome by a simple prediction technique proposed. Output voltage dip is reduced by the feedforward control with the change rate of the estimated load current involved in the deadbeat current control loop. The proposed algorithms are verified by the respective simulation and experiment results.

• Nuclear Engineering and Technology
• /
• 제52권11호
• /
• pp.2522-2534
• /
• 2020

It is well known that the model of nuclear reactors features natural nonlinearity, and variable parameters during power tracking operation. In this paper, a disturbance observer-based adaptive sliding mode control (DOB-ASMC) strategy is proposed for power tracking of the pressurized-water reactor (PWR) in the presence of lumped disturbances. The nuclear reactor model is firstly established based on point-reactor kinetics equations with six delayed neutron groups. Then, a new sliding mode disturbance observer is designed to estimate the lumped disturbance, and its stability is discussed. On the basis of the developed DOB, an adaptive sliding mode control scheme is proposed, which is a combination of backstepping technique and integral sliding mode control approach. In addition, an adaptive law is introduced to enhance the robustness of a PWR with disturbances. The asymptotic stability of the overall control system is verified by Lyapunov stability theory. Simulation results are provided to demonstrate that the proposed DOB-ASMC strategy has better power tracking performance than conventional sliding mode controller and PID control method as well as conventional backstepping controller.

• 한국소음진동공학회논문집
• /
• 제16권1호
• /
• pp.40-49
• /
• 2006

A novel disturbance measurement method, model based disturbance observer (MBDO) for optical disk drives (ODDs), is proposed and the disturbance analysis using the proposed method is performed under various conditions. In ODDs, the quantitative and qualitative analysis for the generated disturbance during normal operation is very important to successful servo loop design. However, the disturbance measurement is difficult, and high precision measurement is necessary. Furthermore, the conventional disturbance measurement method using a LDV (laser Doppler vibrometer) has many difficulties in eccentricity direction due to the vertical movement of an optical disk. To solve this problem, the MBDO is proposed. First, the relationship between the servo loop for ODDs and the generated disturbance are briefly reviewed. Second, the principle of the MBDO is introduced, and the disturbance measurement results, which are measured by the MBDO and a LDV, are compared. In these experiments, test DVD-ROM disks are used to generate quantitative/qualitative disturbance. Then, the disturbance analysis under various conditions is performed using waterfall technique. This technique clearly shows the disturbance trend from the inner part of an optical disk to the outer part of it. Finally, the various disturbances measurement results are summarized and some remarks for it are commented.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
• /
• pp.2783-2786
• /
• 2003

In this paper, the speed controller of permanent-magnet synchronous motor (PMSM) using the RBF neural (NN) disturbance observer is proposed. The suggested controller is designed using the input-output feedback linearization technique for the nominal model of PMSM and incorporates the RBF NN disturbance observer to compensate for the system uncertainties. Therefore the proposed algorithm is robust against the uncertainties of the system. Finally, the computer simulation is rallied out to verify the effectiveness of the proposed method.

• 전자공학회논문지SC
• /
• 제40권4호
• /
• pp.243-250
• /
• 2003

본 논문에서는 RBF 신경망 외란 관측기를 이용한 영구자석형 동기모터의 속도추종 제어기를 제안한다. 먼저 공칭 모델에 대하여 입출력 선형화에 기반한 속도 제어기를 설계하고 RBF 신경망 외란 관측기에 의해 시스템의 블확실성을 보상한다. 시스템의 파라미터와 부하 토크의 변동을 동시에 추정하는 RBF 신경망 외란 관측기를 이용함으로써 제안한 제어 알고리즘은 시스템의 불화실성에 강인한 특성을 갖는다. 마지막으로 모의실험을 통하여 제안된 제어기의 타당성을 검증한다.

• 대한기계학회논문집A
• /
• 제21권2호
• /
• pp.252-260
• /
• 1997

In this paper, a friction compensation method using a disturbance observer is proposed for an impedance control of pneumatic manipulator. It is assumed that the generated torque by a pneumatic actuator can be estimated based on the pressure signals and the discharge volume. In order to improve the dynamic characteristics of the pneumatic actuator driven by meter out method, we construct the inner torque control system by feeding back the generated torque. In order to reduce the influence of disturbances comprising friction torque and parameter variations of plant, the impedance control system is constructed with a disturbance observer which estimates the disturbances based on the generated torque of pneumatic actuator, the angular velocity and the reaction torque. From some experiments, it is confirmed that the proposed control system is effective to improve the robustness for the friction torque in the impedance control of a pneumatic manipulator.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.326-330
• /
• 2001

A nonlinear speed control for a permanent magnet (PM) synchronous motor using a simple disturbance estimation technique is presented. By using a feedback linearization, scheme, the nonlinear motor model can be linearized. To compensate an undesirable output performance under the mismatch of the system parameters and load conditions the controller parameters will be estimated by using a disturbance observer theory. Since only the two reduced-order observers are used for the parameter estimation, the observer designs are considerably simple and the computational load of the controller for parameter estimation is negligibly small. The proposed control scheme is implemented on a PM synchronous motor using DSP TMS320C31 and the effectiveness is verified through the comparative experiments.

• 전력전자학회논문지
• /
• 제6권2호
• /
• pp.149-157
• /
• 2001

본 논문에서는 간단한 외란 관측 기법을 이용한 영구자석형 동기 전동기(Permanent Magnet Syncoronous Motor:PMSM)의 비선형 속도 제어 기법이 제안된다. 피드백 선형화(feedback linearization) 기법을 이용함으로써 비선형 요서가 효과적으로 제거되고 출력 오차 동특성을 선형 제어 기법에 기반하여 설정할 수 있다. 그러나 이 방식은 제어기의 파라미터들이 실제 모터의 파라미터들과 일치하지 않으면 만족스러운 성능을 기대할 수 없다. 본 논문에서는 파라미터들이 실제 모터의 파라미터들과 일치하지 않으면 만족스러운 성능을 기대할 수 없다. 본 논문에서는 파라미터 변동에 의한 비선형 외란을 제거하기 위해 외란 관측 기법을 이용한다. 제안한 방식에는 두개의 축소 차수 관측기만 이용되므로 관측기 설계가 상당히 간단하고 파라미터 추정을 위한 제어기의 계산량에 많은 부담을 주지 않는다. 제안한 관측기를 이용한 비선형 속도 제어 알고리즘이 파라미터 변동에 대해 상인한 제어특성을 가짐을 시뮬레이션과 실험 결과로 입증하였다.

• 제어로봇시스템학회논문지
• /
• 제14권1호
• /
• pp.88-94
• /
• 2008

In this paper, a design method of a missile guidance command is presented considering the dynamics of missile control systems. The design of a new guidance command is based on the well-known PNG(propotional navigation guidance) laws. The missile control system dynamics cause the time-delays of the PN guidance command and degrade the performance of original guidance laws which are designed under the assumption of the ideal missile control systems. Using a backstepping method, these time-delay effects can be compensated. In order to implement the guidance command developed by the backstepping procedure, it is required to measure or calculate the successive time-derivatives of the original guidance command, PNG and other kinematic variables such as the relative distance. Instead of directly using the measurements of these variables and their successive derivatives, a simple disturbance observer technique is employed to estimate a guidance command described by them. Using Lyapunov method, the performance of a newly developed guidance command is analyzed against a target maneuvering with a bounded and time-varying acceleration.

• 한국통신학회논문지
• /
• 제30권4A호
• /
• pp.233-240
• /
• 2005

본 논문에서는 파장분할다중(WDM)망에 적용된 어븀첨가 광섬유증폭기(EBFA)의 이득이 채널의 가감(add/drop)게 따라 변화하는 것을 EDFA의 3-레벨 모델을 기반으로 하는 비례-적분-미분 제어기(PID controller)가 적용된 새로운 외란관측기법을 통해 제어함으로써 이득회복시간을 $3\mu$sec 이하까지 단축시킬 수 있음을 보였다. $3\mu$sec이하의 이득회복 및 안정화 시간은 지금까지 발표된 것들 가운데 가장 빠른 것으로 종전에 2-레벨 EDFA 모델을 기반으로 하는 PI 제어기가 사용된 외란관측기법을 통해 얻었던 $250\mu$sec의 약 $1\%$, 그리고 현재 상용화되어 있는 WDM 망용 EDFA의 가장 빠른 이득회복시간인 $200\mu$sec의 $2\%$도 채 안되는 시간이다. 이러한 결과는 외란관측기의 파라미터와 PI 제어기의 제어 파라미터의 변화에 따른 시스템의 특성 변화를 분석하여 제어기를 최적함으로써 얻어 낼 수 있었으며, 이를 상용화에 적용할 경우, 향후 유동적(dynamic) WDM 망에서 매우 중요한 역할을 할 것으로 전망된다.