Sensor fault diagnosis scheme design for spacecraft attitude control system

Aiming at the sensor subsystem of spacecraft attitude control system equipped with gyroscopes, earth sensors and sun sensors, the observer-based fault detection and fault location problems are studied to ensure the decoupling of fault diagnosis results with actuator faults. The kinematics equation of spacecraft attitude control system and the measurement model of various sensors are given. Then the sensor subsystem is regarded as a virtual system with gyroscope outputs as input and earth sensor outputs and sun sensor outputs as outputs. On this basis, observers with different functions are designed according to different axes of spacecraft attitude control system, and the diagnostic logic is proposed correspondingly. Finally, the effectiveness of the algorithm is verified by the simulation of the satellite attitude control system.