Study of spacecraft minimal-parameter attitude matrix estimation based on the unscented Kalman filter

This paper focused on the inertial-stellar attitude determination system consists of MEMS (Micro electromechanical Systems) gyros and CMOS APS star sensor, selected minimal-parameter attitude matrix estimation from vector observation as the method of attitude determination. But the system model of this method is nonlinear. In order to deal with the nonlinearity, a new UKF (Unscented Kalman Filter) attitude estimator based on UKF and method of minimal-parameter attitude matrix estimation is designed. The results of simulation show that the determination accuracy of the UKF estimator can meet the attitude determination requirements of the most spacecrafts. In addition, the UKF converges rapidly than the EKF, the state estimation precision and the stability of the UKF is better than the FKF.