Coarse Pointing Of Space Optical Communication Terminal Fault-tolerant Control System

This paper briefly introduces its research background and significance,andanalyzes today fault-tolerant control’s development status, and analyze the negativeimpact of the space radiation environment for spaceborne controller, coarse pointingcontrol system’s working principle of the satellite laser communication, laid thefoundation for the further study of the back.This paper research the coarse pointing controller and the motor’s fault toleranceon the coarse pointing control system.By studying the space environment’s negativeimpact on the coarse pointing controller,put forword module-level dual-system backupworking mode to enhance fault tolerance for the coarse pointing controller; againstSingle Event Upset and Single Event Latchup’s phenomenon,respectively designssoftware refresh mechanism based on triple modular redundancy and single eventlatchup protection circuit.By researching common failure mode of controlling motor,put forword dual-channel brushless DC motor to improve the reliable control of themotor. Aftet analyzing the structure of the dual-channel brushless DC motor,build itsmathematical model. On the basis of the mathematical model, using the equivalentcontrol, switching control and fuzzy control to simulink controlling motor.and compareits control effect with the traditional PID control strategy, the results prove that thefuzzy sliding mode control method have better robustness, higher accuracy.This paper design the motor control unit in coarse pointing control system, toaccelerate the speed and reliability of the system communications module, speciallydesigns a custom parallel bus. According to the fuzzy sliding mode control algorithm,design the control program of dual-channel brushless DC motor control; and to enhancethe reliability of the communication system, design the cyclic redundancy checkprogram.