基于运动约束抑制惯导误差的高速列车隧道内定位方法

High-speed train positioning method based on motion constraints suppressing INS error in tunnel

高速列车在隧道内卫星信号缺失,仅依靠由微机电(micro-electromechanical systems,MEMS)器件构成的惯性导航系统(inertial navigation system,INS)误差较大。针对这一问题,在不增加额外传感器的情况下,提出一种利用考虑微惯性测量单元(micro inertial measurement unit,MIMU)在列车上安装角的运动约束来抑制INS误差(consider the installation angles for motion constraints to suppress INS error,CIAMC-INS)的方法。该方法在考虑MIMU安装角的基础上建立运动约束模型;分析转弯对运动约束模型的影响,得到运动约束使用条件;在卫星信号良好且满足运动约束使用条件时估计安装角;将估计得到的安装角应用于运动约束抑制纯惯性导航系统(pure inertial navigation system,P-INS)误差,以提高列车隧道内导航精度。在真实隧道环境和人为断开卫星信号情况下均进行了车载导航试验。试验结果表明,采用CIAMC-INS方法列车在隧道内的定位精度得到明显提高,相比P-INS和传统的不考虑安装角的运动约束抑制惯导(traditional motion constraints suppress INS error,TMC-INS)方法,水平定位精度分别提高85%和42%以上,验证了该方法的有效性。

When the high-speed train is running in tunnel,the global navigation satellite system(GNSS)signal is completely lost,and only relying on the inertial navigation system(INS)composed of micro electro mechanical system(MEMS)devices makes large navigation error.To solve this problem,a method considering the installation angles of micro inertial measurement unit(MIMU)relative to the train body for motion constraints aided inertial navigation system(CIAMC-INS)is proposed,which does not need extra sensors.This method first establishes motion constraints model based on the installation angles of MIMU;secondly,the effect of turning on the motion constraints model is analyzed,and the use condition of motion constraints is obtained;then,the installation angles of MIMU are estimated when GNSS signal is good and the use condition of motion constraints is met;finally,the estimated installation angles are applied to the motion constraints to suppress the error of pure inertial navigation system(P-INS)to improve the navigation accuracy in tunnel.Based on this method,high-speed train navigation tests are carried out both in the real tunnel environment and in the case of artificially disconnected GNSS signal.The experimental results show that the navigation accuracy of the train in the tunnel is significantly improved,which verifies the effectiveness of the method.