Carrier Phase GPS-Aided INS-Based Vehicle Lateral Control

This paper describes the design, analysis, and implementation of a vehicle control system using control state information obtained from a carrier phase (CP) differential global positioning system (DGPS) aided inertial navigation system (INS). Experimental data from CP DGPS/INS control experiments onboard a PATH¹ vehicle is included. This testing was completed with a magnetometer sensing system onboard and running to provide a ground truth reference for comparison with the CP DGPS/INS. Navigation accuracy has previously been demonstrated at the cm level with the full navigation state updated at 150 Hz. In this article, lateral position control performance is demonstrated during challenging high-speed maneuvers with trajectory tracking accuracy at the decimeter level. During these initial experiments, the control state updated at 30 Hz. Increased trajectory following accuracy is possible, but there is an inherent tradeoff between the tracking accuracy and the ride comfort. This level of performance demonstrates that CP DGPS/INS technology has the potential to serve as one component of the reliable multisensor centimeter-level position reference system that is necessary for vehicle position control applications, including automated highway systems (AHS).