基于风险场和多项式的智能车换道轨迹规划  

Intelligent vehicle lane-changing trajectory planning based on risk field and polynomial

作　　者：安政吉 范小宁[1] AN Zhengji;FAN Xiaoning(School of Mechanical Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学机械工程学院,太原030024

出　　处：《南京信息工程大学学报》2025年第2期265-272,共8页Journal of Nanjing University of Information Science & Technology

基　　金：山西省基础研究计划(20210302123212)。

摘　　要：针对智能车在高速路换道场景中的安全性及舒适性问题,提出一种基于安全势场和多项式换道模型的轨迹规划方法.首先,将车辆的运动在Frenet坐标系中解耦为横向与纵向两个维度,采用五次多项式与四次多项式分别生成车辆的横向d-t轨迹簇与纵向s-t轨迹簇;其次,为提升算法效率,根据车辆动力学特性设计了包含加速度、加速度变化率和曲率的轨迹评价指标,对轨迹簇进行初筛后得到候选轨迹;最后,基于安全势场理论结合行车最小安全距离的概念建立包含安全性、舒适性以及效率的轨迹评价函数对候选轨迹筛选出最优轨迹并完成仿真验证.通过搭建高速双车道弯道模型并设计匀速车流和变速车流的不同换道场景对该算法进行仿真验证,结果表明:在换道过程中,自车与各障碍车之间的碰撞风险值始终小于碰撞风险临界值,保证了换道的安全性;在不同行驶工况下,自车的加速度、加速度变化率以及轨迹曲率均小于阈值,表明该换道轨迹规划算法在多种障碍车流中均能保证自车换道的舒适性与换道轨迹的平滑性.A trajectory planning method based on safety potential field and polynomial lane-changing model is proposed to address the safety and comfort issue of intelligent vehicles in highway lane-changing scenarios.First,the vehicle's motion is decoupled into horizontal and vertical dimensions in the Frenet coordinate system,and the horizontal d-t and the longitudinal s-t trajectory clusters are generated by fifth-and fourth-order polynomials,respectively.Second,to improve algorithm efficiency,a trajectory evaluation index incorporating acceleration,acceleration change rate and curvature is designed according to vehicle dynamics characteristics,and candidate trajectories are obtained after initial screening of the trajectory clusters.Finally,a trajectory evaluation function that integrates safety,comfort and efficiency is established based on safety potential field theory and the concept of minimum driving safety distance,to select the optimal candidate trajectory and complete the simulation verification.The proposed approach is simulated and verified by building a high-speed two-lane curve model and designing diverse lane-changing scenarios for uniform and variable-speed traffic flows.Results show that in the lane-changing process,the collision risk value between the ego-vehicle and obstacle vehicles remains below the critical threshold,ensuring lane-changing safety.Furthermore,under different driving conditions,the ego-vehicle's acceleration,acceleration change rate,and trajectory curvature are all within acceptable limits,indicating that the lane-changing trajectory planning approach ensures both comfort and smoothness in various obstacle traffic flows.

关 键 词：智能驾驶 换道轨迹规划 安全势场 Frenet坐标系 多项式 

分 类 号：U463.6[机械工程—车辆工程]