Jiang Qingan, Wu Wenqi, Li Yun, Jiang Mingming
Department of Automatic Control, College of Mechatronics and Automation, National University of Defense Technology, Changsha 410073, China.
Sensors (Basel). 2017 Sep 12;17(9):2083. doi: 10.3390/s17092083.
Railway track irregularity surveying is important for the construction and the maintenance of railway lines. With the development of inertial devices, systems based on Inertial Navigation System (INS) have become feasible and popular approaches in track surveying applications. In order to overcome the requirement of high precision control points, this paper proposes a railway track irregularity measurement approach using the INS combined with the Zero Velocity Updates (ZUPT) technique and sub-decimeter scale landmarks. The equations for calculating track irregularity parameters from absolute position errors are deduced. Based on covariance analysis, the analytical relationships among the track irregularity measurements with the drifts of inertial sensors, the initial attitude errors and the observations of velocity and position are established. Simulations and experimental results show that the relative accuracy for 30 m chord of the proposed approach for track irregularity surveying can reach approximately 1 mm (1) with gyro bias instability of 0.01°/h, random walk noise of 0.005 ° / h , and accelerometer bias instability of 50 μ g , random noise of 10 μ g / Hz , while velocity observations are provided by the ZUPT technique at about every 60 m intervals. This accuracy can meet the most stringent requirements of millimeter scale medium wavelength track irregularity surveying for railway lines. Furthermore, this approach reduces the requirement of high precision landmarks which can lighten the maintenance burden of control points and improve the work efficiency of railway track irregularity measurements.
铁路轨道不平顺测量对于铁路线路的建设和维护至关重要。随着惯性装置的发展，基于惯性导航系统（INS）的系统已成为轨道测量应用中可行且流行的方法。为了克服对高精度控制点的需求，本文提出了一种结合零速更新（ZUPT）技术和亚分米级地标，利用惯性导航系统的铁路轨道不平顺测量方法。推导了从绝对位置误差计算轨道不平顺参数的方程。基于协方差分析，建立了轨道不平顺测量值与惯性传感器漂移、初始姿态误差以及速度和位置观测值之间的解析关系。仿真和实验结果表明，在所提出的轨道不平顺测量方法中，对于30米弦长，当陀螺偏置不稳定性为0.01°/小时、随机游走噪声为0.005°/小时、加速度计偏置不稳定性为50μg、随机噪声为10μg/Hz，且通过ZUPT技术大约每隔60米提供一次速度观测时，相对精度可达到约1毫米（1）。该精度能够满足铁路线路毫米级中波长轨道不平顺测量最严格的要求。此外，这种方法降低了对高精度地标的要求，从而减轻了控制点的维护负担，提高了铁路轨道不平顺测量的工作效率。
