Magnetometer and differential carrier phase GPS-aided INS for advanced vehicle control

Abstract

This paper describes the design, analysis, implementation, and experimental results of a triple redundancy navigation system incorporating magnetometer, inertial, and carrier phase differential Global Positioning System (GPS) measurements. The navigation system is able to accurately estimate vehicle attitude (including yaw) as long as the vehicle velocity is not zero. The motivating application was lateral vehicle control for intelligent highway systems. The system was designed to operate reliably whether or not GPS and magnetometer measurements were available. The navigation system provides vehicle position, velocity, acceleration, pitch and roll, yaw, and angular rates at 150 Hz with accuracies (standard deviation) of 2.8 cm, 0.8 cm/s, 2.2 cm/s/s, 0.03/spl deg/, 0.18/spl deg/, and 0.1/spl deg//s. This navigation state vector was processed to produce a control state vector at approximately 30 Hz. This triplicate redundancy navigation system reliably demonstrated lateral vehicle control in the following situations: both GPS and magnetometer aiding the inertial navigation system (INS), GPS-aided INS, magnetometer aided-INS, and switching between GPS and magnetometer aiding of the INS at random times.