A 3D positioning system for off-road autonomous vehicles

To navigate efficiently on uneven off-road terrain, autonomous vehicles must have reliable 3D positioning capability. Currently most of the positioning systems for autonomous vehicle assume the vehicle runs on a 2D planar plane and ignores the attitude change on pitch and roll. The main problem for 3D positioning over that of ID is accurate 3D attitude estimation. Gyros are subject to drift with changes in temperature. In recent experiments, we employed a new self-calibrated INS system, which is able to bound the attitude errors by complying the integrated attitude with those obtained from the measurements of accelerometers due to the effect of the gravity. Together with the highly precise GPS information, a reliable 3D positioning system was realized by fusing the information from GPS, INS and digital compass together. A direct configured extend Kalman filter was adopted for its simplicity on the implementation. The validity of the proposed system is checked using the experimental results.