变结构力控制方法在油气悬架加载系统中的应用

Application of Variable Structure Force Control Method in Hydro-pneumatic Suspension Loading System

针对油气悬架的非线性和不确定性特性采取变结构的控制方法,选取含有位置、速度和加速度状态的滑模函数,利用指数趋近方式,使系统能够快速地稳定于平衡位置。基于Lyapunov稳定理论,设计了参数摄动和不确定量两种非线性环节的自适应律,结合自适应控制方式减小了滑模带的宽度,从而减小由于开关控制而引起的系统振动。通过仿真分析和实验验证了负载刚度变化时,变结构滑模力加载控制对比常规PID控制的优势,为具有状态反馈的力加载控制系统提供了实用的控制方法。

A variable structure controller was presented for the nonlinear system. The state information including position, veloci- ty and acceleration was selected as cascade function, and the stability and robustness were enhanced by making use of exponential con- vergence. Through classifying factors related to nonlinearity, the Lyapunov function was constructed, and the adaptive control law was developed for the nonlinear system under parameter disturbance and non-parametric uncertainty, which was also adopted to reduce the vibration of responses on cascade surface. Simulation results illustrate that variable structure force loading control is superior to classical PID controller, it proposes a novel control scheme for force loading system with states feedback.