针对传统列车速度测量装置存在量程小、调试复杂等问题，基于扫描激光雷达技术，设计了一套适用于高速列车动态限界测量的列车速度测量系统。将扫描激光雷达固定在距列车10 m左右的位置上，根据激光脉冲飞行时间测距原理，沿列车行驶方向对进入扫描范围内的列车车身逐点扫描，获得由测量点组成的车身轮廓信息；通过最小二乘拟合车厢测量点，得到列车行驶轨迹，确定列车行驶方向；采用分段线性差值确定相邻两次测量周期内列车行驶的距离，完成列车速度的测量。结果表明：该测速系统操作方便，量程可达600 km/h，测速误差控制在±1.2%以内，可以满足高速列车速度测量需求。

Concerning the difficulties such as small measuring range and complicated operation in traditional train speed measure device, a new speed measuring system for dynamic clearance limit measurement of high-speed train is designed based on scanning laser radar. The scanning laser radar fixed in the position of 10 meters from the train. According to the principle of pulsed time-of-flight laser ranging, after the train enters the scan range the scanning laser radar scans the train point by point along the direction of train obtains the body contours. Process measurement data of cars with least square method to obtain the track and direction of the train. The travel distance of the train during two adjacent measurement cycle can be measured through piecewise linear interpolation. Complete the train speed measurement through the above work. Field experiments show that the system is easy to operate with capacity of 600 km/h and the system measurement error is less than 1.2% meets the demand of high-speed train velocity measurement.