地形辅助导航多模式综合完好性监测方法

A multi-mode comprehensive integrity monitoring method for terrain aided navigation

为提升地形辅助导航系统的定位可靠性,避免高度数据异常情况下的误匹配,提出了一种地形辅助导航系统多模式综合完好性监测方法。首先,通过建立滑窗不确定包络对异常的高度数据进行一致性判定,若存在异常则不执行后续匹配计算;其次,构建匹配计算完好性监测机制,在搜索模式下,通过构建搜索异常漏检区对提供的匹配位置进行异常检测,若检测匹配位置异常,则重新进行搜索定位;在跟踪模式下,利用跟踪滤波残差构建异常检测统计量,并计算系统保护水平,实现完好性监测告警。利用真实数字地形高程和实时仿真飞行轨迹进行仿真测试。测试结果表明,多模式综合完好性监测方法能够有效地检测出地形数据、测高传感器和滤波参数等异常情况导致的匹配位置异常,突变故障的检出时间在5 s左右,缓增故障检出时间在10 s左右,隔离故障后地形匹配整体位置误差保持2倍网格分辨率内,提高了地形辅助导航系统的可靠性。

To improve the reliability of terrain aided navigation systems,a multi-mode comprehensive integrity monitoring method for terrain aided navigation systems is proposed.Firstly,the consistency of the abnormal height data is determined by establishing a sliding window uncertainty envelope.If there are anomalies,the matching calculations are not performed.Secondly,a matching computing integrity monitoring mechanism is established.In search mode,a search anomaly missed detection area is constructed to detect the faults.If the matching position anomaly is detected,the search localization is performed again.In tracking mode,anomaly detection statistics are constructed using tracking filter residuals,and the system protection level is calculated to achieve integrity monitoring alarms.Simulation tests are conducted using real digital terrain elevations and real-time simulated flight trajectories.The test results showed that the multi-mode comprehensive integrity monitoring method can effectively detect matching position anomalies caused by abnormal terrain data,height sensors,and filtering parameters.The detection time for sudden faults is about 5 s,and the detection time for slowly increasing faults is about 10 s.After isolating faults,the matching position error remains within 2 times grid resolution.The multi-mode comprehensive integrity monitoring method improves the reliability of terrain aided navigation systems.