采样Kalman滤波器在天文卫星定姿滤波中的应用

Unscented Kalman filter application in astronomical satellite attitude determination

扩展Kalman滤波器(EKF)广泛地应用于卫星定姿问题,但它设计困难,且有发散性问题。该文应用一种采样变换(unscentedtransform,UT)设计了新的姿态确定滤波器UKF(unscentedKalmanfilter)。仿真对比结果表明,UKF滤波器定姿精度好于0.003°。其收敛速度大大高于EKF滤波器。而状态估计精度与EKF相当,方差估计优于EKF,且数值稳定性好。因此该滤波器可用于卫星快速机动过程的定姿。

Extended Kalman filters (EKF) have been used extensively in satellite attitude determination and control problems, but EKF are hard to design and their parameters need to be specially tuned. Moreover, EKF sometimes diverge. This paper presents a filter design method known as the unscented transform (UT) to design a new unscented Kalman filter (UKF) for satellite attitude determination. Simulation results show that the determination accuracy is better than 0.003° which satisfies the attitude determination requirements of satellites. In addition, the UKF converges more rapidly than EKF. While the state estimate precision of the two filters are comparable, the covariance estimation accuracy of UKF is better than that of EKF. These advantages make the new filter suitable for fast satellite maneuvering.