基于可见光通信和接收信号强度检测的列车定位方法研究

精确的列车位置信息是CBTC(基于通信的列车控制)系统保障列车安全高效运行的关键因素。针对地铁独特的隧道环境和列车运营特点,提出一种VLC(可见光通信)和RSSI(接收信号强度检测)相结合的列车定位方法。首先,以朗伯光源模型为基础,构建LED可见光通信的CBTC系统的列车定位模型;其次,利用RSSI值计算隧道壁上LED灯与列车之间的直线距离,并使用三边定位原理和最小二乘法拟合列车定位结果;然后,引入VLC与RSSI相结合的列车定位观测模型和误差模型,对运行中的列车实时定位与误差分析;最后,以成都地铁1号线的真实线路数据和设备参数为依据,验证所提方法的可行性和有效性。研究结果表明:该列车定位方法的最大定位误差为39.23cm,平均定位误差为13.36cm,满足CBTC系统对高精度列车定位的要求,可以作为传统列车定位方法的一种全新选择。

A novel method of train positioning using visible light communication and received signal strength indication

Train position information is the key factor to ensure the safe and efficient operation of trains for CBTC(Communications Based Train Control)systems.Aiming at the unique characteristics of tunnel environment and train operation for urban rail transit,a train positioning method using VLC(Visible Light Communication)and RSSI(Received Signal Strength Indication)has been proposed.Firstly,based on the classical illumination model of Lambert,a train positioning model with LED lamps for CBTC systems has been established.Secondly,the linear distance between the LED lamps on tunnel wall and the train was calculated by using the value of RSSI,and the trilateral positioning principle and the least square method have been adopted to fit the results of train positioning.Furthermore,the observation model and the error model of train positioning,combined with VLC and RSSI,have also been introduced to determine the real-time position and analyze the positioning error for running trains.Finally,according to the real line data and equipment parameters from Chengdu Metro Line 1,the feasibility and effectiveness of the proposed method has been verified.The simulation results show that the maximum error of train positioning of the proposed method is less than 39.23 cm,and the average error is 13.36 cm,which can meet the requirements of high precision of train positioning for CBTC systems and can be used as an alternative choice for traditional methods of train positioning.