针对控制输入通道中存在的时滞对磁流变半主动悬架系统控制品质的影响,建立含时滞的1/4汽车磁流变半主动悬架模型。从磁流变半主动悬架系统的时滞微分方程出发,根据滑模变结构控制理论设计出磁流变半主动悬架系统时滞依赖滑模控制器。通过理论推导,利用线性矩阵不等式(Linear matrix inequality,LMI)处理方法把系统时滞稳定的条件转化为LMI可行性分析,保证系统稳定的最大临界时滞求取转化成LMI中的广义特征值最小化问题。Matlab/Simulink仿真及道路模拟振动台上实车试验结果表明,在系统临界时滞范围内,时滞依赖滑模控制器能从根本上保证系统的稳定性,削弱时滞对系统控制效果的影响,有效地改善汽车的乘坐舒适性。
Aiming to analyze the effect of time-delay on the quality of magneto-rheological semi-active suspension control system,which exists in control input channel,a novel quarter vehicle magneto-rheological semi-active suspension model with time-delay is build.According to the time-delay differential equation and the variable structure control theory,a time-delay dependent sliding mode controller is designed,which transfers the factors of system time-delay stability to feasible linear matrix inequality analysis through theory deduction and LMI method.The problem of solving maximum margin time-delay can be changed to acquire the minimum value of generalized eigenvalue.Both desktop simulation with Matlab/Simulink and bench experimental results show that,in the scale of system margin time-delay,time-delay dependent sliding mode controller will guarantee the stability of system from the root.It can also weaken the influence of time-delay on the system control quality,so as to improve the vehicle ride comfort.