适用于非线性主动悬架滑模控制的线性干扰观测器

Linear disturbance observer suitable for sliding mode control of nonlinear active suspension

基于参考天棚模型主动悬架中存在力的非线性特性、参数不确定以及执行器非理想性等问题,为了削弱这些问题对控制效果的影响,提出一种用于估计非线性参量以及参数不确定、非理想执行器所引起的不确定量的线性干扰观测器,结合滑模控制建立了带有干扰观测器的控制系统;分析了天棚阻尼系数和不确定量对主动悬架控制效果的影响,给出了最优天棚阻尼的选取方法,验证了干扰观测器的有效性;最后,仿真模拟了所提出的控制算法在凸块以及C级路面行驶工况下的控制效果,结果显示:相比于传统没有观测器的基于参考天棚模型的滑模控制,所设计的含有观测器的基于参考天棚模型滑模控制算法在舒适性、稳定性以及安全性方面都有所提升。

The active suspension based on the reference sky-hook model has problems such as nonlinear force,parameters uncertainty,and actuator non-ideality.To weaken the influence of these problems on the control effect,a linear disturbance observer(LDO)was proposed for estimating the uncertainties caused by the actuator imperfections,the nonlinear and uncertain parameters in the active suspension.Combined with sliding mode control(SMC)a control system is established.The influences of the sky-hook damping coefficient and uncertain parameters on the control effect are analyzed.After that,the method for selecting the sky-hook damping coefficient is proposed and the effectiveness of the observer is proved.Finally,the performance indexes of active suspension system with LDO-SMC based on reference skyhook model(LDO-SMCRSM)and SMC based on reference sky-hook model(SMCRSM)are calculated and compared in a bump and class-C road running condition.Simulation results shows that a better suspension performance can be obtained by using the proposed LDO-SMCRSM.