空气悬架混杂系统车身高度与可调阻尼分层控制

Hierarchical Control of Body Height and Adjustable Damping in Air Suspension Hybrid System

针对空气悬架车身高度调节控制过程中车身高度和阻尼器阻尼力难以进行协调控制的难题,提出一种基于混合逻辑动态(MLD)模型的空气悬架车身高度与可调阻尼分层控制策略。考虑空气悬架充放气过程中存在的混杂特性,应用MLD建模方法建立具有电磁阀和磁流变阻尼器的非线性空气悬架混杂系统模型,设计描述电磁阀开关状态的混杂自动机进行车高调节上层控制,基于混杂模型预测控制方法对磁流变阻尼器输入电流进行下层控制,进而通过改变电磁阀开关状态和磁流变阻尼器输入电流实现车身高度与可调阻尼分层控制。在随机路面激励工况下进行仿真验证,结果表明:所提控制方法在有效跟踪车身高度的同时,车身加速度相比于被动悬架和混杂模型预测控制分别降低了34.33%、34.34%,不仅能有效提高车辆乘坐舒适性,也能直接防止电磁阀频繁切换现象的发生,从而延长电磁阀的使用寿命。

To address the difficult problem of coordinated control of body height and damper damping force during air suspension body height adjustment control,a hierarchical control strategy of air suspension body height and adjustable damping based on the mixed logic dynamic(MLD) model was proposed.Considering the hybrid characteristics of the air suspension in the process of inflating and deflating,the MLD modelling method was used to establish a nonlinear air suspension hybrid model with solenoid valves and magnetorheological dampers.The hybrid automaton describing the switching state of the solenoid valves was designed for the upper level control of body height adjustment,and the input current of the magneto rheological dampers was controlled at the lower level based on the predictive control method of the hybrid model.And then hierarchical control of body height and adjustable damping was realized by changing the switching state of the solenoid valves and the input current of the magneto rheological dampers.Through the simulation verification in random road excitation conditions,it could be concluded that the proposed control method could effectively track vehicle height while reducing vehicle acceleration by 34.33% and 34.34% compared to passive suspension and hybrid model predictive control,respectively,which could not only improve the ride comfort of the vehicle,but also directly prevent the frequent switching of solenoid valves and extending the service life of solenoid valves.