【摘要】 理想转向特性对改善车辆操纵稳定性有重要意义。本文中基于LQR最优控制理论,提出了一种新型后轮主动转向变传动比控制策略。首先,综合考虑低速操纵响应性与高速行驶稳定性,建立4WIS电动车理想转向特性;接着根据变传动比曲线设计预期的横摆角速度,并基于LQR最优控制理论提出了主动后轮转向控制策略,以跟踪横摆角速度的预期值;最后,针对典型的双移线工况,进行人车路闭环控制仿真,结果表明,所提出的控制策略较好地实现了理想转向特性。更多还原

【Abstract】 Ideal steering characteristics have important significance to the improvement of handling and stability of vehicle. In this paper,a novel variable transmission-ratio control strategy for rear-wheel active steering is proposed based on LQR optimal control theory. Firstly with concurrent considerations of low-speed handling responsiveness and high-speed driving stability,the ideal steering characteristics of a 4WIS electric vehicle are established. Then,the expected yaw rate is designed according to variable transmission-ratio curve,and by applying LQR optimal control theory,an active rear-wheel steering control strategy is proposed,so as to trace the expected values of yaw rate. Finally,a simulation on human-vehicle-road closed loop control under typical double lane change condition is conducted. The results show that with the control strategy proposed,the ideal steering characteristics can be well implemented.更多还原