车辆半主动座椅悬架滑模变结构控制

Sliding mode variable structure control for semi-active seat suspension in vehicles

针对三自由度的车辆座椅悬架模型,以近似天棚阻尼系统为参考模型,运用滑模变结构方法设计了半主动座椅悬架的滑模控制器.首先将实际被控系统和参考模型间的广义误差动力学引入渐近稳定的滑动模态中;采用极点配置法确定滑模切换面的参数,根据滑模控制理论推出滑模面上的等效控制力,再选择等速趋近律确定实时控制阻尼力.仿真结果表明在时域和频域中,该滑模控制器性能较稳定,较被动及PID控制的座椅悬架系统其减振效果得到明显改善,具有较好的鲁棒性和跟踪性能.

In relation to the dynamic model of a three degree-of-freedom （DOF） seat suspension in vehicles, a sliding mode controller for a semi-active seat suspension system was designed with the sliding mode variable structure control method. The basic idea was to take an approximate sky-hook damping model as a reference model and to force the generalized error dynamics between the reference model and the plant into an asymptotically stable sliding mode. In the proposed controller, the parameters of the switching surface were determined by the pole assignment method. An equivalent reaching law was chosen to determine the real-time damping force after the equivalent control force was derived. Numerical simulations in both time and frequency domains show that this stable controller yields almost perfect tracking to the reference model and has a high robustness against variation and disturbances of model parameters. Additionally, the vibration reduction effect is significantly improved compared with the passive and the Proportional Integration Differentiation （PID） control.