基于车辆制动后期的纵向振动控制

Research on vehicle longitudinal vibration control in late braking period

车辆制动易引起乘坐不适,“点头效应”可以通过半主动/主动悬架进行控制,但制动后期的纵向振动峰值频率在3 Hz左右,处于人体敏感区域中间。文章搭建车辆纵向动力学模型,仿真并试验分析了纵向固有频率;建立动态轮胎模型和制动系统模型,设计了模型预测控制器(model predictive controller,MPC),在车速为0、2 km/h时介入MPC控制并且进行了试验验证。结果表明,在制动后期使用MPC减小制动压力,可以大幅度减小制动后期的纵向振动,制动距离恶化很小。

Vehicle braking easily causes ride discomfort.The“nods effect”can be controlled by semi-active/active suspension,but the peak frequency of longitudinal acceleration vibration in the later period of vehicle braking is about 3 Hz,which is in the middle of sensitive area of human body.The vehicle longitudinal dynamics model is established,and the longitudinal natural frequencies are simulated and analyzed experimentally.The dynamic tire model and brake system model are established,the model predictive controller(MPC)is established based on the time-varying model,when the vehicle speed is equal to 0 km/h and 2 km/h,the MPC control is involved and the test is conducted.The results show that the MPC controller can reduce the braking pressure and the longitudinal vibration in the later period of braking,and the braking distance deteriorates little.