GNSS/INS TIGHTLY COUPLING SYSTEM INTEGRITY MONITORING BY ROBUST ESTIMATION

摘要

Integrity monitoring of the GNSS/INS integrated system is of greatrnimportance for safety critical applications. An improved integrity monitoringrnmethod for GNSS/INS integrated system which is based on robust estimationrnis developed in this paper for the purpose of enhancing the ability of faultrndetection and exclusion. Complete algorithm of fault detection and exclusionrnbased on multi hypotheses innovation separation is built in this paper. Thernrobust estimation and the fault detection and exclusion algorithm arerncombined to improve the performance of both algorithms. The traditionalrnmethods are mostly troubled by the micro and slow growing faults becausernof the innovations’ distortion caused by error tracking of the filter, whichrnbrings difficulties to fault detection and exclusion algorithm. Robustrnestimation is an effective way to reduce the effect of error tracking underrnmicro and slow growing faults by reducing the effect of the faultyrnmeasurements and hence to provide more accurate innovations. By usingrnrobust estimation in GNSS/INS integrated system, the distortion of therninnovations is obviously reduced and the ability of fault detection andrnexclusion is enhanced. The theoretical analysis and computer simulationsrnprove the performance improvements based on the proposed method.