• 동력기계공학회지
• /
• 제13권6호
• /
• pp.129-136
• /
• 2009

A motor cylinder is widely used as an apparatus for transportation of a small scale load. It is, however, difficult for only one motor cylinder to transfer a large scale load such as a weir. The large scale load is transferred by two motor cylinders which are mounted on right and left of load itself. In this case, the displacement difference generated between two motor cylinders, namely, the synchronous error has a bad influence on the transportation. In this study, a synchronous control system is designed to restrain synchronous error caused by skew disturbance. The control system is composed of two disturbance observers and one synchronous controller. Each disturbance observer is designed to restrain the skew disturbance. And the synchronous controller is designed to achieve stable and accurate synchronization. Finally, the simulation results show that the designed control system is effective for the skew disturbance which lead to synchronous error.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
• /
• pp.133-135
• /
• 2006

This paper considers a speed control problem of DC motor under load variations. In order to reduce the effect of load variation, a disturbance observer has been designed for the given system. With a cheap encoder there exists considerable measurement noise in the velocity feedback and it should be reflected in designing the disturbance observer. The authors have obtained the nominal transfer function of a DC motor and designed a disturbance observer for the control purpose. With the disturbance observer a digital controller has been implemented using a DSP(TMS320F2812). Some experiments show the enhanced performance of the control system with the proposed method.

• 제어로봇시스템학회논문지
• /
• 제21권7호
• /
• pp.615-620
• /
• 2015

DOB (Disturbance Observer) is an useful control method for estimating the disturbance applied to dynamic systems. Disturbance observer can be used to implement a robust control system to generate a control input for rejecting the disturbance, and it can be also used to estimate the disturbance to obtain information. The system that uses disturbance estimation is investigated for high performance control such as automatic door systems, walking robot and electric power steering system in vehicles. In this paper, a novel disturbance observer which is called disturbance and current observer for estimating load torque in the motor system is proposed. The difference between the DOB for disturbance rejection and DCOB is mathematically verified. Current and angular velocity are required for estimating the load torque of the motor in DOB. However, the DCOB can estimate load torque and current without current sensor. DCOB is designed based on modeling of the motor system. Appropriate Q-filter is selected and the applicability of DCOB is verified by simulation. The estimated disturbance and current of the electric motor can be verified without current sensor, as experiments of the actual motor system.

• 한국산학기술학회논문지
• /
• 제7권2호
• /
• pp.131-136
• /
• 2006

최근 전통적인 PI제어를 적용한 유도전동기의 제어운전시스템이 산업현장에 많이 보급되어 있다. 그러나, 이러한 방법은 파라미터 변동이나 부하외란에 대해 매우 민감하며, 속도 제어기의 이득이 고정되어 전동기 운전 중에 파라미터가 변하거나 스텝상태로 변화하는 부하가 걸리게 되면 안정성과 추종성능이 악화되는 경향이 있다. 본 논문에서는 전동기의 기계적인 파라미터 변화와 함께 외란의 변화에 대하여 강인한 외란상쇄 제어를 고려하였다. 제안한 시스템은 부하토크를 최소차원 상태관측기를 근거로 추정하였다. 따라서 상태관측기를 사용한 속도제어기는 토크에 대한 Feedforward 루프를 조건으로 사용할 수 있으므로 강인한 속도제어 시스템을 실현할 수 있다. 또한 스텝입력 상태의 외란에 대하여 최적제어 시스템 설계를 하였다.

• Nuclear Engineering and Technology
• /
• 제53권11호
• /
• pp.3685-3693
• /
• 2021

This paper presents a disturbance observer-based robust backstepping load-following control (DO-RBLFC) scheme for modular high-temperature gas-cooled reactors (MHTGRs) in the presence of actuator saturation and disturbances. Based on reactor kinetics and temperature reactivity feedback, the mathematical model of the MHTGR is first established. After that, a DO is constructed to estimate the unknown compound disturbances including model uncertainties, external disturbances, and unmeasured states. Besides, the actuator saturation is compensated by employing an auxiliary function in this paper. With the help of the DO, a robust load-following controller is developed via the backstepping technique to improve the load-following performance of the MHTGR subject to disturbances. At last, simulation and comparison results verify that the proposed DO-RBLFC scheme offers higher load-following accuracy, better disturbances rejection capability, and lower control rod speed than a PID controller, a conventional backstepping controller, and a disturbance observer-based adaptive sliding mode controller.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
• /
• pp.816-819
• /
• 2003

This paper described a robust control of an induction motor using a disturbance cancellation observer of a feedforward control with Matlab simulink. The speed response of conventional PI controller characteristics is affected by variation of load torque disturbance. In this system, the speed control characteristics using a feedforward control toughen about a load torque disturbance.

• Journal of Power Electronics
• /
• 제14권1호
• /
• pp.105-114
• /
• 2014

The sliding mode control (SMC) strategy is applied to a permanent magnet synchronous machine vector control system in this study to improve system robustness amid parameter changes and disturbances. In view of the intrinsic chattering of SMC, a current sliding mode control method with a load sliding mode observer is proposed. In this method, a current sliding mode control law based on variable exponent reaching law is deduced to overcome the disadvantage of the regular exponent reaching law being incapable of approaching the origin. A load torque-sliding mode observer with an adaptive switching gain is introduced to observe load disturbance and increase the minimum switching gain with the increase in the range of load disturbance, which intensifies system chattering. The load disturbance observed value is then applied to the output side of the current sliding mode controller as feed-forward compensation. Simulation and experimental results show that the designed method enhances system robustness amid load disturbance and effectively alleviates system chattering.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.110-112
• /
• 2007

Output voltage waves of a DC/AC inverter system are likely to be distorted if variable loads e.g. motors or rectifiers exist in the output terminal. This paper designs a disturbance observer-based PI controller for a single-phase inverter system that is robust against load changes. In this paper, we regard the output voltage changes due to various loads as disturbances of the control system, Then we design a disturbance observer for estimation of the disturbances caused by the load current and any other error sources (such as parameter uncertainties and model mismatches etc.). In order to test the performance of the proposed control law, simulation studies are carried out for a single-phase inverter system using SimPowerSystems of Matlab Simulink. Compared to a simple PI control, the disturbance observer-based controller shows enhanced performance in transient responses for step load changes.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 B
• /
• pp.1088-1090
• /
• 2002

This paper described a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional PI controller characteristic is affected by variations of load torque disturbance. In the proposed system. the speed control characteristic using a feedforward control isn't affected by a load torque disturbance.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2002년도 전력전자학술대회 논문집
• /
• pp.150-153
• /
• 2002

This paper designed a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional Pl controller characteristic is affected by variations of load torque disturbance. In the proposed system the speed control characteristic using a feedforward control isn't affected by a load torque disturbance.