基于改进PID控制的电液伺服系统执行器运动轨迹仿真  

Simulation of Actuator Trajectory of Electro-hydraulic Servo System Based on Improved PID Control

作　　者：黄文娟[1] 赵伟 HUANG Wenjuan;ZHAO Wei(Department of Electrical and Mechanical Engineering,Tangshan Vocational and Technical College, Tangshan Heibei 063004,China;College of Intelligence and Information Engineering, Tangshan University,Tangshan Hebei 063000,China)

机构地区：[1]唐山职业技术学院机电工程系,河北唐山063004 [2]唐山学院智能与信息工程学院,河北唐山063000

出　　处：《机床与液压》2020年第21期171-175,共5页Machine Tool & Hydraulics

基　　金：河北省自然科学基金资助项目(E2017203232)。

摘　　要：电液伺服系统执行器运动轨迹跟踪容易受到外界干扰,导致控制系统不稳定。为解决此问题,设计小波神经网络PID控制系统,并对控制效果进行仿真验证。建立电液伺服阀简图模型,创建阀芯运动的动力学模型,分别推导出控制阀、液压执行器和比例溢流阀动力学方程式。采用小波神经网络对传统增量式PID控制器进行改进,利用MATLAB软件对改进后的控制系统进行仿真;对比分析改进前、改进后系统液压执行器的跟踪轨迹。结果表明:液压执行器在没有受到外界波形突然干扰情况下,2种控制方法都能较好地实现轨迹跟踪;在受到外界波形突然干扰情况下,采用增量式PID控制的液压执行器运动轨迹与期望轨迹存在较大误差,采用小波神经网络PID控制的液压执行器运动轨迹与期望轨迹存在较小误差。所设计的控制系统响应速度较快,能够自适应在线调整控制参数,有效地抑制外界环境对控制系统的干扰,从而提高液压执行器运动轨迹跟踪精度。The tracking of the actuator trajectory of the electro-hydraulic servo system is easy to be disturbed by outside world,which leads to the instability of the control system.To solve this problem,a wavelet neural network PID control system was designed,and the control effect was verified by simulation.The schematic model of the electro-hydraulic servo valve was established,the dynamic model of the valve core motion was established,and the dynamic equations of the control valve,hydraulic actuator and proportional relief valve were deduced respectively.Wavelet neural network was used to improve the traditional incremental PID controller,and the MATLAB software was used to simulate the improved control system;the trajectory of the hydraulic actuator before and after improvement was compared and analyzed.The results show that the two control methods can be used to realize the trajectory tracking of the hydraulic actuator well without sudden interference of the external waveform;in the case of the sudden interference of the external waveform,the trajectory of the hydraulic actuator controlled by incremental PID has a large error with the expected trajectory,but the trajectory of the hydraulic actuator controlled by the wavelet neural network has small error with the expected trajectory.The designed control system has a fast response speed and can adjust the control parameters online adaptively,which can effectively suppress the interference of the external environment to the control system and so as to improve the tracking accuracy of the hydraulic actuator trajectory.

关 键 词：电液伺服系统 小波神经网络 增量式PID控制 轨迹误差 仿真 

分 类 号：TH137[机械工程—机械制造及自动化]