UKF容错滤波方法在自主导航中的应用研究

Research on the Fault Tolerant UKF Applied on Autonomous Navigation

地磁场向量可描述成卫星的位置函数,以地磁场强度向量为观测量,利用三轴磁强计的测量信息即可实现近地卫星的自主导航。但当测量值存在野值时,滤波会出现偏差、收敛变慢甚至发散。将UKF滤波容错方法用于磁测自主导航,构造出一种基于残差正交性判别的UKF(Unsend Kalman Filter)容错滤波方法,来实现野值的实时修正和故障诊断,使滤波器具有较强的鲁棒性。仿真结果表明该方法有效。

Magnetic field vector is a function of the satellite＇ s position. Autonomous LEO satellite navigation can be achieved based on the measurement data of the onboard three axis magnetometer （TAM）. For the orbit estimation algorithm based on the measurement of the geomagnetic field vector, when measurement data influenced by oufliers, filtering advents deviation, convergence becomes slow and even diffuses. Based on residual orthogonal UKF（Unscedted Kalman filer） Fault tolerant filtering method, the instant modifying and fault diagnosis are implemented and the filter obtains stronger robustness. Simulation results show the effectivity of the method.