汽车避障工况下稳定性控制研究

Research on controlling stability of vehicle under obstacle avoidance condition

为改善车辆紧急避障工况下的稳定性,建立滑模控制系统。设计七自由度非线性整车动力学模型和人车路闭环模型,运用滑模变结构理论,以车辆实际横摆角速度和理想的横摆角速度之差为输入变量,以前轮转角响应紧急避障要求为控制目标,以跟踪理想横摆角速度为目的进行控制计算。结果表明,紧急避障工况下采用滑模控制系统设计的路径跟踪控制器,能够控制车辆跟踪规划的理想避让路径,横摆角速度幅值为0.234 rad/s,小于未加控制车辆的横摆角速度,响应速度更快;经过滑模控制的车辆在路径跟踪过程中质心侧倾角最大值为0.037 rad,小于未受控制的车辆的相应值。

For the sake of solving the stability control problem of the vehicle under the emergency obstacle avoidance condition,a sliding mode control system was built. A seven degree of freedom nonlinear vehicle dynamics model and the human-vehicle-road closed loop model were designed.. The input variable was the difference between the actual yaw rate and the ideal yaw rate based on the theory of sliding mode variable structure. The control target was that the front wheel steering angle must response to the emergency avoidance requirements.The ideal yaw rate was calculated as the tracking target. The results show that the path tracking controller using the sliding mode control method can control the vehicle tracking planning ideal avoidance path under the emergency obstacle avoidance condition, and the max yaw rate was 0.234 rad/s, and that the max side dip angle was 0.037 rad narrower than the uncontrolled vehicle.