基于差动制动的汽车拖车组合系统动态稳定性滑模控制

Sliding mode control of dynamic stability of car-trailer combinations based on differential braking

为了提高汽车拖车组合系统(CTC)的动态稳定性,首先建立了基于差动制动的CTC动力学模型,确定了CTC在一定前轮转角输入下的稳态转向响应;然后将滑模控制方法应用到CTC动态稳定性控制中,创建了以稳态响应下横摆角速度为控制目标的动态稳定性控制系统;最后通过计算一定前轮转角输入下的两节车身横摆角速度需求,将差动制动产生的横摆力矩分别施加在两节车身,抑制CTC的车身摆振.仿真结果表明:动态稳定性控制系统加快了车身横摆的收敛速度,有效消除了车身摆振;相较于传统的抑制横摆运动的控制方法,所提出的控制系统保证了系统对于前轮转角的动态响应,实现了保障合理横摆运动、抑制多余横摆运动的效果,将质心侧偏角误差降低了40%,附加横摆力矩的响应时间缩短了30%,有效地提高了CTC的动态稳定性.

To improve the dynamic stability of car-trailer combinations(CTC),a dynamic model for the CTC based on differential braking was established firstly,and the steady-state steering response of the CTC under a certain front wheel rotation angle input was determined.Then,the sliding mode control method was applied to the CTC dynamic stability control,and a dynamic stability control system using the yaw rate as the control target under the steady state response was established.Finally,the yaw torque generated by differential braking was applied to the two car bodies to suppress the shimmy of the CTC by calculating the yaw velocity requirements of two car bodies under the input of certain front wheel rotation angle.Simulation results show that the dynamic stability control system accelerates the convergence of the yaw rate and eliminates the body sway.Compared with the traditional yaw motion control,the control system can ensure the dynamic steering response.The reasonable yaw motion is guaranteed and the instable yaw motion is restrained.The error of the side slip angle is reduced by 40%and the response time of additional yaw moment is shortened by 30%.The dynamic stability of the CTC is effectively improved.