四种卡尔曼滤波器在仅视线测量相对导航中的性能比较

针对航天器交会时在仅有视线测量条件下的相对导航问题,比较了扩展卡尔曼滤波（extended Kalman filter,EKF）、无迹卡尔曼滤波（unscented Kalman filter,UKF）及平方根形式的卡尔曼滤波（square-root extended Kalman filter,SREKF以及square-root unscented Kalman filter,SRUKF）在这一导航问题中的性能.介绍了仅有视线测量条件下相对导航的特点以及上述4种卡尔曼滤波算法；建立了追踪航天器和目标航天器间相对动力学方程以及基于仅视线测量相对导航时的量测方程；结合3种典型的相对运动形式进行了数值仿真.仿真结果表明：在仅视线测量相对导航中,4种算法的精度处于同一量级；UKF估计相对距离的精度稍优于EKF；SREKF和SRUKF估计相对距离的精度稍优于EKF和UKF.

Comparison of Four Different Kalman Filters for Relative Navigation Based on Line-of-Sight-Only Measurement

The performances of the extended Kalman filter （EKF） , unscented Kalman filter and squareroot Kalmau filters （SREKF, SRUKF） for relative navigation based on line-of-sight-only measurement in spacecraft rendezvous operation are compared. The characteristics of the proposed relative navigation and the algorithms for the above four Kalman filters are introduced. The relative dynamic models of the chaser and the target spacecraft as well as the measurement model of the line-of-sight-only relative navigation are established. Numerical simulations are undertaken for three typical relative motions. The simulation resuits show that the accuracies of the relative navigation based on line-of-sight-only measurement via the four filtering algorithms （EKF, UKF, SREKF, and SRUKF） are at the same level. The UKF performs a little better than the EKF, and the SREKF and SRUKF perform a little better than the EKF and UKF on the accuracy of the relative distance.