Fusion of GPS/INS/Odometer measurements for land vehicle navigation with GPS outage

This paper deals with the hybridization of Global Positioning System (GPS) with an Inertial Navigation System (INS) and an Odometer, for land vehicle navigation, and more precisely with the calibration of inertial sensor errors. We focus here on the complementary characteristics of GPS and odometer to provide periodic corrections to Inertial Navigation System alternatively in different environmental conditions. In open sky, where GPS signals are available, GPS is integrated with INS. Meanwhile, in degraded GPS environments, where GPS is unreliable or unavailable, odometer replaces GPS to integrate with INS. This estimation problem is solved by a Kalman filter (KF), since it deals with non-linear problems and statistics.