FAILURE DETECTION ISOLATION AND RECOVERY IN AN INTEGRATED NAVIGATION SYSTEM

摘要

An Inertial Navigation System(INS), the Global Positioning System(GPS), and a ground based transponder system(RRS) can all be used to provide the user with a navigation solution. Yet by integrating these three navigation systems with an extended Kalman filter(EKF), a navigation solution is attained that benefits from the information of all three subsystems. This research develops a multiple model EKF failure detection, isolation, and recovery(FDIR) algorithm using a Chi-Square failure test to provide robust navigation solution to measurement failures. The algorithm specifically counters failures in the GPS and RRS range measurements. Analysis is conducted using a Kalman filter development package known as the Multimode Simulation for Optimal Filter Evaluation (MSOFE). Both a large order truth model for the navigation system (in which a full 24 satellite constellations is modeled) and a reduced-order Kalman filter are developed. Results suggest that the multiple model algorithm can correct for all single measurement failures. Integrated navigation system, Extended kalman filter, Failure detection, Robust navigation.