跨距与运动约束的隧道内列车惯性导航方法

Inertial Navigation for Trains in Tunnel with Catenary Span and Motion Constraints

高速列车通过隧道时无法接收卫星信号,而仅依靠惯性导航的定位误差增长较快,针对这一问题提出了一种利用列车和隧道特点辅助惯性导航的方法。该方法使用GNSS和运动约束估计IMU相对于车体的安装角,并在隧道内使用运动约束和路标跨距约束提高列车的定位精度。基于状态变换卡尔曼滤波设计了系统方程和观测方程,与传统方法相比,系统方程更接近线性定常系统,滤波时间更新方程与测量修正方程可采用相同的计算频率,减小实时计算负担,有利于高速运动下的组合导航。基于实际的高速列车行驶实验,设计了列车穿越隧道的仿真实验,实验结果表明,两种约束辅助的惯性导航在隧道内的定位精度有明显提高,优于3‰行程。

As the high-speed trains cannot receive satellite signals when passing through tunnels,and the position error of inertial navigation increases rapidly,a method of assisting inertial navigation by using the characteristics of trains and tunnels is proposed.This method uses GNSS and motion constraints to estimate the installation angles of the IMU relative to the train,in addition,motion constraint and landmark catenary span constraint are used to improve localization accuracy in tunnels.System equations and observation equations are designed based on the state transformation Kalman filter.Compared with the traditional method,the system equation is closer to linear stationary systems.The filtering time update equation and the measurement correction equation can use the same calculation frequency,which reduces the real-time calculation burden and is beneficial to the integrated navigation during high-speed motions.Based on actual high-speed train experiments,a simulation experiment of trains crossing tunnels is designed.The experimental results show that the localization accuracy of inertial navigation assisted by the two constraints in the tunnel is significantly improved,which is better than 3‰.