将GPS和列尾装置结合可以构成一个冗余的列车完整性检查系统。在列车行驶过程中,由于在列车尾部车钩安装的GPS天线容易被车厢遮挡,常规卫星定位方法受到限制,无法利用GPS进行列车完整性检查。本文提出一种基于GPS和虚拟卫星组合定位完成列车完整性检查的方法。利用列车首部的定位信息确定一颗虚拟卫星,虚拟卫星和3颗可视卫星即可实现列尾定位解算,通过列车首部和列车尾部的位置信息实时地测算车长变化,达到检查列车完整性的目的。本文分析GPS和虚拟卫星组合定位模型,推导定位模型算法和列车完整性检查算法,并进行可行性分析和算法验证。实验表明,列尾定位精度达到3m以内,列车长度误差在10m以内,该方法可满足列车完整性检查的要求。
GPS integrated with the train end device constitutes a redundancy system to monitor train integrity. In the moving process of a train, the train end will fail to be positioned via GPS and train integrity monitoring based on GPS will be unavailable due to blocking of the satellite signals at the end of the train. A train integrity monitoring method based on GPS and virtual-satellite integrated location was proposed. Combined with positio- ning information of the train head, a virtual satellite was established. Thereby using a virtual-satellite and three visible satellites, positioning of the end of the train was accomplished. The varying length of the train was calculated on a real-time basis by using the positioning information of the head and end of the train, so that train integrity was monitored. The GPS and virtual-satellite integrated location model was analyzed. The posi- tioning model algorithm and train integrity monitoring algorithm were deduced. Feasibility analysis and vertifi- cation of the algorithms were made. The results show the accuracy of positioning of the train end is below 3 meters and the calculated error of the train length is less than 10 meters, thus satisfying the requirements of train integrity monitoring.