Abstract: Description of vehicle dynamic test trajectory is an important step in vehicle detection.In this paper, based on the analysis of the existing sampling methods to describe the vehicle dynamic test trajectory, a vehicle dynamic trajectory tracing system based on programmable logic controller (PLC) is designed, which using the liquid injection method. The Taguchi method is used to analyze the design parameters, and the influences of nozzle diameter, flow rate of proportional valve and nozzle height on the trajectory width and trajectory blur time are studied when the road surface, test temperature range and vehicle speed have been set. The system has the characteristics of controllable flow rate of jet fluid with the speed, adjustable track line width, instant on and off, simple operation, etc., which brings great convenience and accuracy for the description of vehicle dynamic trajectory

Key words: Dynamic test; Trajectory description; Liquid spraying method; Design of experiment

摘要： 汽车动态试验轨迹描绘是汽车检测工作中的一个重要环节。论文在分析现有描绘车辆 动态试验轨迹的采样方法的基础上，以喷液法为背景设计出了一种基于可编程逻辑控制器 （PLC）的车辆动态轨迹描绘系统。采用 Taguchi 方法进行设计参数分析，研究了在路面、试 验温度范围和车速一定时，喷嘴直径、比例阀流量及喷嘴高度对轨迹宽度和轨迹模糊时间的 影响。该系统具有喷液流量随车速可控、轨迹线宽可调、即开即关、操作简单等特点，为车 辆动态轨迹的描绘带来极大的便利性和准确性。

关键词: 动态试验；轨迹描绘；喷液法；试验设计