电液位置伺服系统模型辨识与非线性控制

Model Identification and Nonlinear Control of an Electro-hydraulic Position Servo System

针对电液伺服系统非线性、参数时变的特点,为提高系统的性能,首先介绍了电液位置伺服控制系统的组成与工作原理,讨论了系统的非线性数学模型,利用实时工作间(RTW)的半实物仿真环境和MATLAB系统辨识工具箱,对电液位置伺服系统进行了系统模型辨识及验证。在此基础上,以辨识得到的模型为控制对象提出了一种Bang-Bang与模糊PID非线性控制方案,与传统PID以及模糊PID控制方法进行了仿真比较。结果表明,采用Bang-Bang与模糊PID复合控制,在系统参数变化、外界扰动的影响下,系统的快速性提高,稳态误差得到消除,具有较好的动态鲁棒性能。

According to the nonlinear and parameter time-varying characteristics of an electro-hydraulic servo system,in order to improve its performance,the composition and principle of the electro-hydraulic position servo control system is introduced and its nonlinear mathematical model is established firstly.Then,system model identification and verification were carried out based on hardware-in-the-loop simulation environment of real-time workshop（RTW） and system identification toolbox in MATLAB.A hybrid nonlinear control strategy composed of a bang-bang controller and a fuzzy-PID controller,for which the parameters of the PID controller can be adjusted online by the output of the fuzzy controller.Furthermore,the hybrid nonlinear control strategy is compared with the classical PID control and fuzzy-PID control scheme through simulation.The simulation results show that the steady-state error of the system is eliminated,and bang-bang＋fuzzy-PID strategy has better dynamic robustness even under the influence of parameter variation and external perturbation.