Low cost SINS/GPS integration for land vehicle navigation

The recent progress in the field of micro-electromechanical systems (MEMS) has made low cost inertial devices become a possible option for land navigation. However, the weak stand-alone accuracy and poor run-to-run stability of low cost inertial devices make them not usable as a sole navigation system. Even the integration of them as a supporting device into a navigation system requires non-traditional approaches and algorithms. The objective of this paper is to assess the feasibility of using this kind of low cost inertial device, specifically the Crossbow DMU-6X, integrated with GPS information, to provide the navigation capability to bridge the GPS outages for tens of seconds. A series of tests were conducted in a land vehicle. Post-processing results show that when the GPS signal is available, the position accuracy of low cost SINS/GPS integration is same as that of GPS only. With the complete loss of GPS signals, position error is shown to be less than 10 meters, after 10 seconds. From these results, we can conclude that although GPS and current low cost IMU integration cannot improve the absolute positioning accuracy, it has a high data update rate and can give motion information by SINS only when GPS is not available for a short time, such as in heavily forested areas, in urban centers, in buildings or underground.