Positioning an autonomous off-road vehicle by using fused DGPS and inertial navigation

The paper deals with positioning system for an autonomous vehicle ARSKA. Localization of the vehicle is based on fusion of internal dead reckoning navigation and periodic absolute position measurements. Fusion is done by using Kalman-filtering technique. Similar kind of approach is used in correcting the heading measurement. This is important because the position error is mostly result of the accumulated heading error. The resulting accuracy depends on the accuracy of the dead reckoning estimation and on the accuracy and frequency of the absolute position measurement. As an absolute position measurement system several alternatives can be used. Two different systems have been used with the vehicle; an external optical measurement device, tachymeter, and different combinations of DGPS. Also a real guarding application will be discussed in the paper.