A New Composite Control Strategy of Space Laser Pointing Mechanism Based on Active Disturbance Rejection Controller

The satellite laser communication pointing system driven by a permanent magnet synchronous motor (PMSM) should have high-precision fixed-point pointing and tracking performance. However, the system motor parameter perturbation and friction disturbances affect the performance of the system. A composite control strategy for the space laser pointing mechanism based on an active disturbance rejection controller (ADRC) is proposed to solve these problems. In order to mitigate the adverse effects of current loop parameter perturbation and speed loop friction disturbance on control performance, the improved current controller and speed controller based on ADRC are designed. On these bases, an improved feedforward position controller is designed. The proposed control strategy can effectively suppress the parameter perturbation of the current loop and the friction disturbance of the speed loop, thus improving the position tracking accuracy of the pointing mechanism for the laser communication system. Experiments are carried out based on the laser pointing mechanism platform to demonstrate the correctness and effectiveness of the proposed strategy.