油气悬架车身高度控制研究

Study of Vehicle Height Control of Hydropneumatic Suspension System

针对油气悬架系统,提出了一种由PID控制器和滑模控制器组成的双闭环控制的车身高度控制策略,外环为高度控制环,内环为力跟踪控制环。外环利用PID控制算法实现对期望高度的精确跟踪,输出一个最优控制力,该最优控制力作为内环的给定。内环的作用是通过油气悬架实现对最优控制力的跟踪,针对建立的油气悬架非线性数学模型,内环采用滑模控制算法,并对滑模控制存在的颤振问题进行了修正。结果表明,该控制器能满足车身高度控制的精度要求,同时具有较好的快速性和稳定性。

A vehicle height control strategy was proposed for the hydropneumatic suspension system, which adopted a double closed-loop control system composed of a PID controller and a sliding mode controller （SMC）. The outer loop utilized the PID controller to track the desired height and the inner loop was the force tracking control. The output of the outer loop, which was an optimal control force, served as the input of the inner loop. The function of the inner loop using the SMC was to track the optimal fbrce in the hydropneumatic suspension. The chattering problems existed in the SMC were corrected for the established nonlinear mathematical model. The results indicate that the control strategy proposed in this paper could satisfy the accuracy requirement of vehicle height control with excellent rapidity and stability.