GNSS-based End-of-Train Device Performance Evaluation and Improvement by Means of Particle Filter Algorithm

Abstract

The Train Integrity Monitoring System (TIMS) function is becoming more and more demanding for the next generation for train control (NGTC) in both China and European train control systems. Traditional train integrity detection provides the integrity status of the train by monitoring the status of brake pipe pressure without adding equipment a major the train, but not possible to provide redundancy to meet the SIL 4 (Safety Integrity Level 4) requirement of the train control system <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</sup> . GNSS-based train localization provides essential location and velocity data for each wagon, the information transmitted to head-of-train (HOT) device, then the integrity can be determined. End-of-Train (EOT) device is normally mounted on the coupler of the last wagon, the observation condition for GNSS is not good, normally “half-sky”. In view of the above conditions, this paper constructs three different constraint scenarios: open sky, general constraint and severe constraint based on the laboratory GNSS simulator by setting the EOT user antenna directivity pattern, and evaluates the positioning accuracy in the constraint scenarios. On this basis, the state equation and observation equation of the system are established with a simulation example, and the positioning results are optimized by using the particle filter algorithm. The results show that the average location error in the unobstructed scenario is 0.12m; The average value of general constraint error is 3.93m, and the average value of error after pf processing is 3.02m; The mean value of severe constraint location error is 11.94m, and 8.83m after PF filtering. This filtering algorithm can improve the location accuracy to a certain extent.