融合侧翻稳定性的SUV换道轨迹规划方法研究

Research on SUV Lane Changing Trajectory Planning Method Integrating Rollover Stability

针对运动型多功能汽车(Sport utility vehicle,SUV)换道过程中侧翻安全问题,提出融合侧翻稳定性的SUV换道轨迹规划方法。建立三自由度车辆动力学模型,推导SUV侧翻稳定性及侧滑稳定性评价指标。采集自车状态及环境信息,将换道轨迹规划分成预规划和重规划两个阶段;预规划阶段采用五次多项式模型生成横向轨迹簇,重规划阶段考虑周围车辆动态变化,生成包含自车纵向速度信息的轨迹簇。融合侧翻稳定性指标、侧滑稳定性指标以及双圆拟合的车辆外形最小距离,构建代价函数;进行轨迹簇碰撞筛选、稳定性筛选及轨迹选择。运用内点惩罚函数进行轨迹优化,求解最优轨迹。选取两种典型工况进行换道轨迹规划仿真,结果表明SUV沿着该方法规划的轨迹行驶可完成换道躲避障碍物,且横向位移小、换道效率高,可有效避免侧翻危险。

Aiming at SUV rollover safety during lane changing,an SUV lane changing trajectory planning method integrating rollover stability is proposed.A three degrees of freedom vehicle dynamics model is established.Rollover and sideslip stability evaluation indexes of SUV are derived.According to the vehicle status and environmental information,the lane change trajectory planning is divided into two stages:pre-planning and re-planning.In the pre-planning stage,the quintic polynomial model is used to generate the lateral track cluster of lane change.And in the re-planning stage,the dynamic change information of surrounding vehicles is considered to generate the track cluster with longitudinal speed change.The cost function is constructed by combining rollover stability index,sideslip stability index,and the minimum distance of vehicles shape fitted by double circles.Then a trajectory is selected from the track cluster using the cost function.Furthermore,the interior penalty function is used to optimize the selected trajectory.Finally,SUV lane change trajectory planning method is simulated in two typical cases.The results show that,driving along the trajectory planned by the proposed method,SUV can complete lane change and avoid obstacles,with small lateral displacement,high efficiency,and high level rollover stability.