Integrated Attitude Determination Algorithmof Star Sensor/Gyroscope Based on Kalman Filterwith Weighted Index

Solar radiation?infrared radiation and flash back have an effect on integrated attitude determination system with star sensor/gyroscope so that measurement noise of star sensor is variable. Extended Kalman filter is not adaptable in order that filter parameters can not match actual model of measurement noise correctly, so the capability is poor, even out of order. This paper presents an algorithm of Kalman filter with weighted index based on fuzzy control theory. The algorithm monitors residuals real time, exports the weighted index by fuzzy control system and then adjusts measurement noise model of filter online, so filter parameters can match actual model of measurement noise constantly in order to improve capability and stability of the filter availably. The simulation results that executes with the measurement noise of gradual and sudden change based on integrated attitude determination system of star sensor/gyroscope show that the algorithm of Kalman filter with weighted index is better than extended Kalman filter in the aspect of accuracy and stability.