主动四轮转向汽车最优控制及闭环操纵性仿真

摘要

鉴于汽车正常情况下都运行在侧向加速度较小的线性工作区域，对基于线控技术的主动四轮转向汽车进行了前、后轮转角最优跟随控制器的设计和算法推导，建立了“人车路”闭环操纵系统模型，并进行闭环系统仿真和安全性评价。结果表明：基于最优控制的主动四轮转向汽车同时实现了减小车身质心侧偏角与跟踪期望横摆角速度的控制目标，改善了车辆高速行驶下的转向响应特性；相对于传统前轮转向汽车与比例控制四轮转向汽车，基于最优控制的主动四轮转向汽车具有更好的路径跟随精度和主动安全性。%In view of that vehicles normally operates at linear region where its lateral acceleration is rela-tively small, the optimal tracking controllers for the steering angles of front and rear wheels in an active four-wheel steering vehicle are designed based on the technology of control by wire, a model for ‘driver-vehicle-road’ closed-loop handling system is built, and the simulation and safety evaluation of closed-loop system are conducted. The re-sults show that the active four-wheel-steering vehicle under optimal control can achieve the control objective of both reducing the sideslip angle of vehicle center of mass and tracking desired yaw rate, and improve the steering re-sponse characteristics of vehicle in high-speed driving. Compared with traditional front-wheel steering vehicle and four-wheel steering vehicle with proportional control, the active four-wheel steering vehicle with optimal control has higher accuracy in path tracking and better active safety.