座椅悬架不匹配干扰估计全程滑模控制研究

The global sliding mode control for seat suspension system based on unmatched disturbance observer

针对含有人体动态的座椅悬架系统,通过合理选择状态变量及干扰变量,将地面激励建模成系统的一类可从控制通道输入的匹配干扰,同时考虑模型参数变化这一类不匹配干扰对系统的影响,基于滑模控制理论,设计了全程滑模切换函数;结合不匹配干扰估计器,构造了座椅悬架系统控制器;根据Lyapunov理论,证明了系统的鲁棒稳定性。利用座椅位移量和人体加速度量这两个可测输出量,设计了滑模观测器,实现了对状态变量的估计。仿真结果表明,相比于LQR和传统的滑模控制方法,带不匹配干扰估计的全程滑模控制方法可以使得座椅悬架系统在刚度系数和阻尼系数变化以及恶劣地况的情况下,获得更佳的动态性能及鲁棒性。

For a class of seat suspension systems with body dynamics,an active controller is designed in this paper based on the sliding mode control approach.Matched road excitations and unmatched parameter perturbations in the system are considered,and a global sliding switching function is given.Based on Lyapunov theory,the robustness of the system is verified.The system states are observed by employing seat displacement and body acceleration based on the sliding mode observer.Simulation results demonstrate that the desired dynamics and robustness can be achieved in the case of varying stiffness and damping and bad road condition,which is otherwise by LQR controller and traditional sliding mode controllers.