城市轨道交通封闭曲线线路列车定位技术

针对城市轨道交通中列车在线路上循环运行的特点,在分析现有列车定位方法的基础上,提出具有封闭曲线特征轨道线路基于绝对位置编码的列车定位技术。在轨道线路沿线每个待定位置上设置一个0或1的二值标记,对待定的绝对位置进行编码,通过检测唯一的绝对位置编码值来实现列车的定位。结合封闭曲线线路的特点,线路上的二值标记按照m序列布置,绝对位置编码序列由n次本原多项式生成。根据封闭线路待定位置的总数,对m序列采用截短或补零的方法,确定绝对位置编码序列的长度。当列车在线路上运行时,通过车载阅读器顺序检测二值标记,在移位存储器中构成绝对位置编码值,利用生成绝对位置编码序列的反馈逻辑函数进行容错处理,输出定位信息。二值标记采用附加的扣件螺母或射频电子标签等方式实现。该技术可以实现高精度、低成本和高可靠性的列车定位。

Train Positioning Technology for the Closed-Loop Track Railway in Urban Mass Transit

The train positioning technologies in urban rail transit are analyzed.According to the characteristic that train runs circularly along fixed rail track,train positioning technology based on absolute position encoding is proposed to the closed-loop track railway in urban rail transit.The single biconditional marker,whose value is 0 or 1,is placed on each position of rail track.The absolute positions of rail track can be encoded by the biconditional markers.The train positioning information can be extracted by decoding the exclusive absolute position code.In allusion to the characteristic of the closed-loop track railway,the biconditional markers are arranged according to m sequence.The absolute position encoding sequence is generated by primitive polynomial n,and its length is determined by the number of absolute positions of rail track.The method for shortening m sequence is introduced.The means of shortening m sequence or inserting 0 in proper place of m sequence can meet the case of the absolute position encoding for the closed-loop track railway with discretionary number of positions.The biconditional markers placed on the rail track are detected sequentially by the on-board reader,and checked by the feedback logic function of generating absolute position encoding sequence.The exclusive position code consists of the binary information in the shift register.The selectable scheme of biconditional marker is the attached nut of rail clamp or RFID tag and so on.The presented technology can improve the precision and reliability of train positioning,and reduce the cost.