Abstract: Aiming at the problem of the uncontrolled motion of the functional layer of the multilayer coaxial system of the direct-drive VICTS satellite antenna caused by the carrier impact, a fault-tolerant control algorithm for the rampant phenomenon was carried out. Firstly, the mathematical model and system composition of the multilayer coaxial direct-drive servo system were analyzed. Secondly, based on the motion state of the out-of-control layer and the conditions of the impact fault, a new type of fault-tolerant control algorithm for impact faults was put forward, which consists of three parts, that is planning the new motion state according to the current state of the out-of-control layer when the out-of-control occurs, smoothly switching to the original condition after the out-of-control was recovered, and adopting the real-time speed to predict and compensate control system delay. Finally, corresponding experiments were designed to verify the effectiveness of the proposed fault-tolerant control system for faults occurring in the acceleration, uniform speed, and deceleration segments, as well as for the upper and lower layers under various working conditions. The research is of great reference significance for improving the disturbance resistance of satellite antennas.

Key words: VICTS satellite communication antenna, fault-tolerant control, impact failure, motion planning, control system delay compensation