多源导航系统软、硬故障检测新方法研究

故障检测和隔离对提高无人机的导航精度和可靠性有重要意义.针对残差卡方算法对小值软故障灵敏度差,改进序贯概率比(SPRT)算法无法判断故障结束时间的缺陷,提出了一种联合故障检测算法.该算法依靠残差卡方算法判断故障结束时间,从而及时对改进SPRT算法检测值进行修正,使改进SPRT算法能继续检测非第一次故障.改进SPRT算法对故障的灵敏度高,且残差卡方算法能准确判别故障结束时间.仿真结果表明,该综合算法对小值软故障、大值阶跃故障都有很好的检测效果,有效提高了系统的故障检测能力及灵敏度,增强了组合导航系统的可靠性.

New Method for Soft and Hard Fault Detection in Multi-source Navigation System

Fault detection and isolation are very important to improve the UAV navigation accuracy and reliability. The residual chi square algorithm is poor sensitive for small values of soft fault and improved SPRT algorithm can't judge the ending time of the fault, so this paper presents an integrated fault detection algorithm. If the residual chi square algorithm determined the fault ending, the improved SPRT algorithm detection value is corrected on time. As a result,the improved SPRT algorithm can detect faults after the first time. Because of the improved SPRT algorithm is of high sensitivity to fault and residual chi square algorithm can accurately distinguish the fault ending time, the simulation results show that this integrated algorithm has good detecting effection for small values of soft fault or large values step fault. Therefore, this integrated algorithm can effectively improve the ability and sensitivity of the system fault detection and enhance the reliability of the integrated navigation system.