基于安全距离的雾天车辆换道轨迹模型

Vehicle lane-changing trajectory model in foggy weather based on safety distance

为提升恶劣天气下的车辆安全性,基于安全距离提出一种轨迹模型,首先,引入附着系数、延迟反应时间,确定雾天条件下的换道初始距离与跟驰距离;其次,考虑曲率、横向速度与横向加速度对舒适性与安全性的影响,通过余弦与双曲正切函数建立换道轨迹,从而建立雾天的车辆换道模型;然后,在跟踪控制部分,基于车辆动力学建立模型预测跟踪控制器,尽可能按照规划轨迹的同时控制前轮转角生成满足动力学约束的实际路径;最后,在Matlab/Simulink与Carsim的联合环境中进行仿真验证。结果表明:基于安全距离的换道模型能够完整的规划整个过程,且横向加速度、前轮转角、质心侧偏角满足舒适性与稳定性的要求,从而规划安全稳定的换道轨迹。

In order to improve vehicle safety in bad weather,a trajectory model was proposed based on safety distance.Firstly,adhesion coefficient and delay reaction time were introduced to determine initial distance of lane changing and following distance under foggy conditions.Secondly,considering influence of curvature,lateral speed and lateral acceleration on comfort and safety,lane-changing trajectory was established through cosine and hyperbolic tangent functions,so as to establish a vehicle lane-changing model in foggy days.Then,in tracking control part,a model predictive tracking controller was developed based on vehicle dynamics,which generated a real path that satisfied dynamic constraints by controlling steering angle of front wheels as much as possible according to planned trajectory.Finally,simulation verification was carried out in joint environment of Matlab/Simulink and Carsim.The results show that the lane-changing model based on safety distance can completely plan entire process.And lateral acceleration,front-wheel angle,and sideslip angle meet the requirements of comfort and stability,generating a safe and stable lane-changing trajectory.