Study on Fault Detection of Star-Sensor Based on UKF

摘要

The fault detection of star sensor in satellite when no telemetry data from the gyroscope can be obtained is investigated. An algorithm based on the unscented Kalman filter (UKF) is proposed to indicate the occurrence of the fault. By adding the angular speed of the satellite into the state equation, the UKF is designed to estimate the angular and the angular speed of the satellite. After that, a comparison between the measured and the estimated value of both the angular and the angular speed is made. In this way, the star sensor fault can be finally detected. Two fault cases (abrupt constant fault and noise increase fault) are taken into consideration in the simulation to show the validness of the present algorithm. Furthermore, a test verification by using the real telemetry data on orbit is performed to demonstrate that the present algorithm can detect the star sensor fault effectively. In application, the developed fault detection algorithm can be employed in the ground measurement and control station to monitor the star sensor fault such that the fault can be detected immediately and the alarm indicating the occurrence of the fault will be given.