Track Map-Aided Capture of Virtual Balises: A Compatible Approach to Satellite-Based Railway Train Control

The use of a Global Navigation Satellite System (GNSS) is a significant requirement of next-generation railway train control systems. As one effective approach to integrate the GNSS positioning service into a train control system, the virtual balise (VB) solution makes it compatible with current system specifications and ensures the benefits in terms of cost efficiency and the autonomy of the train-borne subsystem. To create a VB system that performs normal balise functions, the standard VB solution suggests a capture interval (CI). However, a fixed CI cannot adapt to different train operating conditions, and thus, a full VB capture rate cannot at the same time be guaranteed with the desired spatiotemporal capturing accuracy level. In this study, a novel VB capture solution is proposed. The track map is involved in the VB capture to enable map matching of train location, interactive multiple model-based forward prediction of the next VB approaching status, and identification of the exact capture time. A field test of high-speed railway with accurately measured balises shows that the proposed approach can realize the full availability of VB capture without the difficulty of having to select a unique CI value. The capturing error and time offset are greatly reduced compared with the standard VB capture strategy using different CIs, which is significant for the future development and implementation of novel train control systems.