Fault-tolerance method of integrated navigation system for gradual changing fault based on ARCH model

Addressing the issue of fault detection and fault-tolerance for gradual changing faults, a novel fault-tolerance method of integrated navigation system was proposed for gradual changing fault with smaller extent of difficult fault-tolerance by considering the unique characteristics of the navigation sensor. The concept of fault factor and its fuzzy evaluation based on autoregressive conditional heteroskedastic (ARCH) model were presented, and then fault factor used to correct the observation noise covariance to prevent gradual changing fault from affecting the filter. Simulation and experimental analyses show the effectiveness of the method which can effectively improve the estimating precision of the integrated navigation system when gradual changing faults exist in system.