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Comparing with the indirect drive gimbal servo system of single gimbal control moment gyroscope (SGCMG), direct drive gimbal servo system based on permanent magnet synchronous motor (PMSM) can achieve higher precision and faster response. However, the difficulty of PMSM controller design increases, because PMSM has to endure larger multi-source and multi-band disturbances due to the lack of a decelerator...
For high agility and high precision attitude maneuver of remote sensing satellites, the Control Moment Gyroscope (CMG) is expected to supply the torque more accurately, which means the disturbance torque on its gimbal axis should be minimized to reduce the pulsation of the gimbal speed. In this paper, the torque generated by the wheel imbalance is analyzed, and the gimbal system model is built. To...
Single gimbal control moment gyroscope (SGCMG) is used as the actuator of attitude control system for modern satellites. High precision control of the SGCMG gimbal servo system is difficult to achieve because of the existing multi-source and strong coupling disturbances. In this paper, multi-source disturbances are modeling, meanwhile, a high precision controller is designed, including a variable...
Deficient capability of high frequency disturbance torque attenuation restricts further improvements on the speed control performance of single gimbal control moment gyro (SGCMG) gimbal servo system. In this paper, a variable structure controller (VSC) combined with repetitive controller (RC) is proposed. Utilizing the characteristics of invariance and fast response of VSC and the characteristics...
Ultra-low speed control strategy is a difficult problem in the single gimbal control moment gyro (SGCMG) gimbal servo system. Speed detection resolution and disturbance torque attenuation are two major factors that restrict further improvements on the ultra-low speed control performance. In this paper, a novel ultra-low speed control strategy is proposed, including a multi-cycle backward difference...
A new reliable sensorless startup strategy of brushless DC (BLDC) motor is proposed to prevent long time integration commutation error specialized for large inertia load and to adapt large disturbance torque fluctuation. It includes four segments: orientation segment, I/f startup segment, observer startup segment and back EMF startup segment. Experimental results show that the proposed method could...
Attenuation of disturbance torque fluctuation is a significant way for improving the performance of Single Gimbal Control Moment Gyro (SGCMG) gimbal servo system. Based on the analysis of the causes and influences of the disturbance torque, fuzzy logic controller combined with acceleration disturbance observer is proposed to prevent wide margin disturbance torque fluctuation. Simulation results show...
SRM is suitable to be used as drivers of electric bicycle (E-bike). A nonlinear dynamics model based on Matlab/Simulink of E-bike and four regenerative braking strategies of SRM are presented in this paper, such as most feedback power control strategy, most feedback efficiency control, fixed torque control, fixed feedback current control. A hybrid control strategy of PWM mode and current chopping...
The starting current is big and the torque is small when the motor begins to start with the nominal voltage .The discrete variable frequency method can solve the above two questions, at the same time brings the torque oscillation.The paper analyses the cause in detail, and then presents the solved method: the combination between discrete variable frequency method improvement and power factor closed...
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