含时滞的参数不确定主动悬架离散系统鲁棒控制

Robust control for discrete active suspension with time delay and parameter uncertainty

针对主动悬架存在传输时滞和参数不确定性的控制问题,设计了含时滞的参数不确定鲁棒控制器。首先,运用线性分式变换方法推导出含时滞的参数不确定主动悬架状态空间方程,采用零阶保持器取值处理和双线性变换,建立主动悬架离散控制系统模型。其次,以车身垂向加速度为车辆悬架系统的最优化输出目标,采用Lyapunov泛函方法,推导出系统渐进稳定的鲁棒控制器充分条件,得到满足最优H∞性能指标约束的反馈控制律,再通过求解线性矩阵不等式获得控制器参数。最后,进行数值算例仿真,结果表明,相较于只考虑时滞的控制器,含时滞的参数不确定鲁棒控制器具有更好的控制效果和鲁棒性,且受采样周期与不确定参数的耦合影响较小。

In order to solve the control problem of transmission delay and parameter uncertainty in active suspension,a parameter uncertain robust controller with delay was designed.Firstly,the state space equation of the uncertain active suspension with delay was derived by using linear fractional transformation method,and the discrete system model of active suspension system was established by using zero-order retainer value processing and bilinear transformation.Secondly,the vertical acceleration was taken as the optimal output target of the vehicle suspension system,and the Lyapunov functional method was adopted to derive sufficient conditions for the robust controller to make the system asymptotically stable,and the feedback control law satisfying the optimal H∞performance index constraint was obtained.Then the controller parameters were obtained by solving linear matrix inequality.Finally,numerical simulation results show that compared with the controller with time delay only,the parametric uncertain robust controller with time delay has better control performance(including robustness),and is less affected by the coupling between sampling period and uncertain parameters.