具有非线性不确定参数的电液伺服系统自适应backstepping控制

Adaptive backstepping controller for electro-hydraulic servo system with nonlinear uncertain parameters

针对电液伺服系统中存在非线性不确定参数的问题,提出了一种采用积分型Lyapunov函数的自适应backstepping控制方法.首先定义积分型Lyapunov函数,将电液伺服系统中的非线性不确定参数转化为线性表示;然后逐步递推设计backstepping控制器,同时在控制律中加入阻尼项,从而补偿外界干扰对控制性能的影响;基于Lyapunov稳定性方法,设计了参数自适应律,并且在自适应律中引入充分光滑投影算子,实现对电液伺服系统中不确定参数漂移的抑制作用.搭建了AMESim与MATLAB的联合仿真平台,对所设计的自适应backstepping控制器进行仿真,作为对比,设计了不带有非线性参数估计的自适应backstepping控制器和PID算法.仿真表明,本文所设计的控制器具有良好的跟踪性能和补偿非线性不确定参数变化的能力.

An adaptive backstepping control method with an integral-type Lyapunov function is designed for an electrohydraulic servo system with nonlinear uncertain parameters. Firstly, the integral-type Lyapunov function is defined to transform the nonlinear parameters to the linear parameters. Then, we design the adaptive backstepping controller with the nonlinear-damping which compensates for external disturbance. Based on Lyapunov method, parameter update laws are given. And sufficiently smooth projection operators are used to conquer the effects of the parameter-drift. Finally, a cosimulation platform using AMESim and Matlab is build to test the performace of the desigend controller. By contrast, PID and the adaptive backstepping controller without considering nonlinear parameters are designed and simulated, respectively.The simulation results show that the designed adaptive backstepping controller using nonlinear parameter adaption laws gives a satisfactory tracking performance and can compensate for the nonlinear uncertain parameters.