三种卫星故障检测策略的对比研究与仿真

Comparison and Simulation of Three Satellites' Failure Detection Methods

故障检测是保证导航系统完好性的重要途径。针对接收机自主完好性监测算法RAIM需要至少5颗可见星时才能进行故障检测的问题,在惯性/卫星组合导航系统的框架下,通过构建能反映卫星故障特征的检验统计量,并根据检验统计量的分布确定相应的检测门限,提出了解分离和残差外推两种卫星故障检测方案。仿真结果表明:解分离算法能在存在RAIM漏洞时检测故障且易于进行系统重构,但其故障检测效率不高;残差外推法适用于检测慢变故障。仿真结果表明,改进方法故障检测效率有较大提高,甚至在只有三颗可见星时仍能较快地检测出慢变故障。

Failure detection is an important way to guarantee the integrity requirement of navigation system.In order to deal with the problem of RAIM＇s requirement of at least five visible satellites to complete failure detection,in the frame of inertial/satellite integrated navigation system,by establishing detecting statistics that can reflect the satellites＇ failure and calculating the corresponding detection thresholds,two schemes of solution separation and residue extrapolation were proposed to detect the satellites＇ failures.The analysis and simulation show that the solution separation method can successfully detect satellites＇ failures even under RAIM hole condition,and the system can easily complete configuration with this scheme,but the failure detecting efficiency is not very high; residue extrapolation method takes the advantage of detection slowly growing failure,and its failure detection efficiency is greatly improved,and it can quickly detect slowly growing failure even there being only three visible satellites.