High-speed train positioning method based on motion constraints suppressing INS error in tunnel

Abstract

When the high-speed train is running in tunnel, the global navigation satellite system (GNSS) signal is completely lost, and only relying on the inertial navigation system (INS) composed of micro electro mechanical system (MEMS) devices makes large navigation error. To solve this problem, a method considering the installation angles of micro inertial measurement unit (MIMU) relative to the train body for motion constraints aided inertial navigation system (CIAMC-INS) is proposed, which does not need extra sensors. This method first establishes motion constraints model based on the installation angles of MIMU; secondly, the effect of turning on the motion constraints model is analyzed, and the use condition of motion constraints is obtained; then, the installation angles of MIMU are estimated when GNSS signal is good and the use condition of motion constraints is met; finally, the estimated installation angles are applied to the motion constraints to suppress the error of pure inertial navigation system (P-INS) to improve the navigation accuracy in tunnel. Based on this method, high-speed train navigation tests are carried out both in the real tunnel environment and in the case of artificially disconnected GNSS signal. The experimental results show that the navigation accuracy of the train in the tunnel is significantly improved, which verifies the effectiveness of the method.