摘要
为提高低附着极限操纵工况下半挂汽车列车队列的跟驰控制性能,保证队列运行的安全性,提出考虑个体车辆动力学特性的半挂汽车列车队列协调控制方案。首先建立了12自由度(12DOF)的非线性半挂汽车列车模型作为队列中个体车辆的动力学仿真模型,其次设计了基于车头时距策略和模型预测控制(MPC)方法的上层队列跟驰控制器,一个显著特点是加速度约束可以根据路面附着的变化自动调整,即在进行上层队列的控制决策时就考虑了个体车辆动力学的潜能,使决策的期望跟驰加速度不超出个体车辆动力学极限,实现了上层队列跟驰与下层车辆动力学稳定性的协调控制。为准确识别路面附着工况,设计了基于带有遗忘因子的递归最小二乘法的路面附着系数估计算法。最后,以3辆车组成的半挂汽车列车队列为对象,对控制方案进行仿真验证,并分析了轴间制动力分配对队列跟驰控制和队列中各车辆横向稳定性的影响。研究结果表明:所提出的队列控制方案可以实现队列的跟驰控制,验证了在低附着路面条件下通过上下层的协调控制,可以显著减小跟驰误差和车间距波动,缩短跟驰调整时间。通过仿真分析还得到不同的制动力分配方案对队列跟驰性能的影响差别较大,并且还会显著影响车辆的横向稳定性。
To improve the following control performance of a tractor semi-trailer platoon in critical operation conditions and further guarantee the running safety of the platoon,a coordinated control scheme for a tractor semi-trailer platoon is proposed by taking individual vehicle dynamics into account.First,a twelve-degree-of-freedom(12 DOF)non-linear tractor semi-trailer vehicle model is developed and presented.Second,an upper vehicle-following controller for the platoon is developed based on the time headway policy and the model predictive control(MPC)method.One of the remarkable features of this controller is that the constraint of acceleration is able to adjust automatically with the variations of road adhesion.That is to say,the margin of vehicle dynamics stability is estimated and evaluated in the upper platooning control decision.Hence,the desired vehicle-following acceleration decided in the upper platooning controller would not exceed the stability margin of the individual vehicle dynamics.This is the coordinated control between the upper platooning following and the lower individual vehicle dynamics stability.An algorithm for estimating road adhesion is developed based on the recursive least square method in order to identify the road condition in real time.Finally,the proposed platooning control scheme is evaluated by simulations based on a three-vehicle platoon,and the influences of braking force distribution on the platooning following control performance and the lateral dynamics of the platoon have been analyzed qualitatively as well.It is revealed that the platooning following control is realized by the proposed control scheme.Proved in low adhesion conditions,the fluctuations of the following error relative to the lead vehicle and the spacing between two adjacent vehicles,and thus the regulating time of the platoon,would be reduced remarkably and in low adhesion conditions,the distribution of braking force would greatly affect not only the platooning control performance,but also the individual vehicle lateral dynamics.
作者
杨秀建
廖涛
李金雨
Yang Xiujian;Liao Tao;Li Jinyu(Faculty of Transportation Engineering,Kunming University of Science and Technology,Kunming City,Yunnan Province 650500,China)
出处
《农业装备与车辆工程》
2019年第12期54-58,共5页
Agricultural Equipment & Vehicle Engineering
关键词
汽车工程
车辆动力学
模型预测
车辆队列
智能汽车
制动力分配
automotive engineering
vehicle dynamics
model predictive
vehicular platoon
intelligent vehicle
braking force distribution
作者简介
杨秀建(1980—),男,教授,博士生导师,研究方向:车辆动力学及控制技术。E-mail:yangxiujian2013@163.com;廖涛(1995—),男,硕士研究生,研究方向:车辆动力学及控制技术。E-mail:965434761@qq.com。
