Integrated INU/DGPS for autonomous vehicle navigation

An integrated navigation system, combining an inertial navigation unit (INU) and a differential global positioning system (DGPS), is described and performance results are presented for the Kawasaki MULE test vehicle for autonomous vehicle application. Continuous real-time navigation data is required to provide this autonomous vehicle with high-rate data for following a pre-computed path. The US Army/Honeywell modular azimuth position system (MAPS) INU and a pair of Ashtech Z-12 stand-alone GPS receiver units, operated in a differential mode, are elements of the navigation system. Their integration is via a navigation Kalman filter implemented in an external VME computer. The navigation filter's design objectives are included. Test results show a real-time high rate positioning accuracy that is generally within 1/2 meter compared to post-processed DGPS positions.