两级故障检测与隔离方法在组合导航中的应用分析

Dual-stages Fault Detection and Isolation Method for Integrated Navigation System

GPS信号的突变故障会严重影响甚至破坏GPS/INS组合系统的导航性能。针对此问题,提出了两级故障检测与隔离算法。首先利用开方检验法对系统层面上的故障进行探测,然后结合w检验法对系统内部故障进行定位与隔离。与单一的开方检验法比较,该方法有效降低了故障检测的误警概率,实现了子系统内部故障的正确定位与隔离。仿真结果表明,本文提出的改进算法能够有效地利用多余观测量,从而提高了组合导航系统的抗差性能。

The abrupt errors contained in GPS signals influence,or even completely ruin the GPS/ INS integrated navigation system.To solve this problem,a dual-stages fault detection and isolation method was proposed.Firstly,the chi-square test was implemented to detect the existence of faults on the whole system level.Then,w test was investigated to identify and isolate faults within each subsystem.Compared with traditional fault detection and isolation methods,the proposed method can reduce the probability of miss-detection and improve the probability of successful identifying faults in each subsystem.The simulation results show that the navigation accuracy and stability of the GPS/INS integration system can he effectively improved by using this proposed method.