SINS AIDED GPS INTEGRITY MONITORING FOR SINS/GPS TIGHTLY INTEGRATED NAVIGATION SYSTEM

A new approach suitable for real-time detecting and isolating GPS faults in pseudo-range and pseudo-range rate is investigated for tightly coupled SINS/GPS integrated navigation system. First, the SINS/GPS tight integration system structure, the system state and measurement equations are deduced based on error models and Kalman filter theory. Then, a GPS fault detection method based on residual chi-square test and a GPS fault isolation method based on Chebyshev theorem are designed through analyzing the statistical characteristics of the residuals of the kalman filter. This new fault detection and exclusion (FDE) algorithm unrestricted by number of visible satellites can dynamically monitor pseudo-range and pseudo-range rate of GPS, and isolate the faulty signal in real-time. Simulation results show that the proposed algorithm can further improve the system's performance in anti-interference ability, thus guarantee the navigation accuracy under satellite faults.