用于列车定位的RAIM算法改进研究

Research on Improvement of RAIM Algorithm for Train Positioning

针对北斗卫星导航系统应用于列车在定位过程中所存在的故障卫星导致定位结果不准确问题,在传统RAIM检测算法的基础上,提出一种新的用于列车定位的RAIM算法。该算法通过可见卫星数目、完好性告警限值的约束,判断改进算法的可用性,并在故障卫星检测过程中引入加权因子C以降低由于直接检测而引起的较高漏警率,实现对列车的精确定位。以青藏铁路数据为对象进行实例仿真,结果表明:改进的RAIM算法有效改善了列车定位精度,降低了检测过程中的漏警率,提高了北斗卫星导航系统在列车定位应用上的安全性及可靠性。

Aiming at the problem that the BeiDou satellite navigation system applied in train positioning results occasionally in inaccuracy due to faulty satellite, a new RAIM algorithm for train positioning is proposed based on the traditional RAIM detection algorithm. This algorithm determines the availability of the improved algorithm by restricting the number of visible satellites and integrity warning limits, and introduces the weighted factor C in the fault satellite detection process to reduce the high alarm leakage rate caused by direct detection and realize accurate train positioning. The simulation of the Qinghai-Tibet line shows that the improved RAIM algorithm effectively improves train positioning accuracy, reduces false alarm rate during detection process, and provides safety and reliability for the BeiDou satellite navigation system in train positioning.