车道偏离预警系统中偏离时间的估算方法

Estimation Method of Time-to-Line Crossing for Lane Departure Warning System

车道偏离时间(TLC)是指车辆从当前位置行驶至车道边界线的剩余时间,是车道偏离预警系统触发警告的判断依据,因此其计算精度至关重要.文中结合车辆运动学理论和三角函数知识研究车辆行驶在直线和曲线路段的轨迹形状,建立车辆轨迹为直线和曲线情况下的TLC估算模型,最后分别就横向距离、相对偏航角和曲线道路半径对TLC的影响进行了仿真分析.结果表明:在直线路段,TLC与相对偏航角成反比,与横向距离成正比;在曲线路段,TLC与相对偏航角和道路曲线半径成反比,与横向距离成正比,而当车辆从相反方向偏离时,对应关系则相反.文中研究能有效降低以TLC为决策标准的车道偏离预警系统的误警率.

Time-to-line crossing （TLC）is defined as the remaining time that a vehicle travels from the current position to the lane boundary. It has been used as a trigger warning criterion for lane departure warning system,so that its calculation accuracy plays a key role. In this paper,the trajectories of vehicles driven on straight and curved road sections are investigated on the basis of vehicle kinematics and trigonometric function,and the estimation models of the TLC respectively in straight and curved vehicle paths are then presented. Finally,the effects of vehicle lateral distance,relative yaw angle and road curve radius on TLC are analyzed in a simulative way. The results show that （1）in straight paths,TLC is inversely proportional to the relative yaw angle but is proportional to the transverse distance;（2）in curved paths,TLC is inversely proportional to both the relative yaw angle and the path curve radius but is proportional to the transverse distance;and （3 ）the above-mentioned relationships are opposite to those when the vehicle runs across a lane border in an opposite direction. This research effectively reduces the false alarm rate for lane departure warning systems using TLC as the decision criterion.