Simplified GNSS Fusion-based Train Positioning System and its Diagnosis

Abstract

In this paper, two simple GNSS-based positioning methods are proposed and their diagnostic functions for GNSS failure are tested. Firstly, the odometer-based method, which are proposed in our previous research [1], is concretized to be implemented for general cases. This method detects faults in the GNSS solution due to satellite failure or local effects using both odometry and track geometry of the onboard system. It enables to monitor all three-dimensional solution error so that higher sensitivity for the fault detection can be achieved. Secondly, single-axis accelerometer-based approach is newly proposed. Positioning architecture of this method is designed in traveling distance domain with the configuration of single-axis accelerometer installed along the forward direction. The diagnosis of GNSS signal can be done easily in one-dimensional space. Therefore, the latter method is expected to give greater sensitivity to detect GNSS failures while maintaining a relatively simple architecture. Both methods are tested in simulation, and their abilities for detecting fault in GNSS signal are investigated