高速车辆车道偏离辅助控制研究

针对高速公路上因驾驶员注意力不集中或疲劳容易发生车辆偏离车道事故的问题，提出基于动态车辆横越车道线时间(Time to lane crossing，TLC)触发阈值的辅助控制决策策略和基于差动制动的车道偏离辅助控制方法。根据车-路航向角偏差、路面附着、车速、驾驶员反应时间及执行机构响应时间实时计算动态TLC触发阈值，进行预警和辅助控制决策。在辅助控制决策的基础上，基于预瞄点处的车-路偏差、车辆状态和道路附着限制计算期望的横摆响应，设计滑模控制器控制辅助横摆力矩，通过差动制动产生横摆力矩，使车辆横摆响应跟踪目标值，达到车道偏离辅助控制的目的。在Carsim/Simulink联合仿真平台上对基于差动制动的车道偏离辅助控制方法进行仿真试验，研究结果表明所提出方法将车辆限制在车道范围内，有效避免车道偏离事故发生。建立由CarsimRT/LabviewRT实时平台及转向、制动执行机构组成的车道偏离辅助控制系统快速原型试验台架，对基于差动制动的辅助控制方法进行台架试验，其结果与Carsim/simulink联合仿真结果基本一致。

Research on Lane Departure Avoidance System of High-speed Vehicle

The large number of lane departure accidents in high way is due to driver’s inattention and fatigue. A new strategy for the decision of lane departure avoidance, based on dynamic threshold of time to lane crossing(TLC) is presented. The dynamic threshold is calculated by vehicle-lane heading, vehicle speed, road adhesion and reaction time of the implementing agencies and driver in real-time. The decision making of lane departure warning and assistance control is based on the dynamic threshold. A new approach for lane departure avoidance is proposed, which applies additional yaw moment to vehicle to correct lane departure of vehicle by means of differential braking. The desired yaw rate is determined by considering vehicle-lane deviation, vehicle dynamic and limitation of road adhesion. A sliding mode controller(SMC) is designed to control the additional yaw moment. The yaw moment is produced by the distribution of brake forces between the same side brakes with fixed ratio, and lane departure avoidance is carried out by tracking desired yaw response. The proposed lane departure avoidance system(LDAS) is evaluated in Carsim/simulink. Simulation results showed that the proposed method can restrict vehicle into lane range and avoid lane departure accident. A rapid prototyping test platform for LDAS is established, which is composed of CarsimRT/LabviewRT real-time platform, real steering and brake system. The proposed LDAS is validated on the platform. The test result is consistent with the simulation result.