Study on Performance Analysis of the Train Location Device based on Train-borne Sensors

초록

GNSS (Global Navigation Satellite System) is a widearea navigation infrastructure system with global coverage using navigation systems located on earth orbits. Through the application of global navigation satellite system to railways, it is possible to contribute to the enhancement of interoperability, vehicle's intellectualization and increase of maintenance efficiency, as the train location function based on track circuits would be onboard. However, as GNSS is the radio navigation system which uses the propagation delay time of satellite signal and triangular surveying, it is necessary to ensure that at least four satellites are visible. On the contrary to the environment visibility of aviation or marine, it is difficult to assure the sufficient visibility due to the geographical effect in the railway which is the representative ground transportation mean. The visibility problem in GNSS applications increases positioning error and it is impossible to make succeeding positioning. For the purpose of the application of GNSS to railway fields, a solution is needed to overcome the visibility problem and increase positioning accuracy and availability. And it is also required to secure a high level of reliability in order to expand and apply to various railway fields. In this paper, we implement GNSS based train-borne location device with a high level of availability and accuracy by integrating other sensors (e.g. inertial sensors and tachometer) with GPS receivers. Furthermore, the performance of availability and accuracy has been demonstrated through field tests.