基于Fuzzy-PID的棉花打顶升降装置设计与试验

Design and Experiment of Cotton Topping and Lifting Device Based on Fuzzy PID

为解决棉花打顶机作业过程中由于仿形时与刀盘移动滞后、定位精准度低,导致的棉花漏打、过打及伤苗的问题,基于模糊控制技术对棉花打顶装置高度控制系统进行研究。以3MDZF-6棉花打顶机升降系统为分析对象,确定了刀盘在升降过程中的定位精度要求。以液压阀-液压缸为对象,在AMESim中建立打顶升降装置的控制模型,并将其导入到MatLab中,设计相应的模糊规则和模糊控制器,对其进行仿真分析,从超调量和响应时间两方面验证了PID和模糊PID控制方法的可行性。仿真结果表明:无外界干扰的情况下,PID参数分别为100800、500、30时,输入信号达到稳态的响应时间为0.55s;模糊PID控制下输入信号达到稳态的响应时间为0.31s。经过对比分析固定参数PID控制和模糊PID控制在不同扰动下的控制效果,发现模糊PID控制系统的超调量为0.84%,输入信号达到稳态所需的时间为0.39s,小于固定参数PID的0.64s。该方法实现了打顶升降装置的位移控制,提高了刀盘的定位精度及控制系统的抗干扰性和鲁棒性,可为棉田环境下的棉花打顶升降装置的精确控制问题提供借鉴。

In order to solve the problems of cotton missed beating,over beating and seedling injury caused by the lag of movement between copying and cutter head and low positioning accuracy during the operation of cotton top beating machine,this paper studied the height control system of cotton top beating device based on fuzzy control technology.Taking the lifting system of 3MDZF-6 cotton top beamer as the analysis object,the positioning accuracy requirement of cutter head in the lifting process was determined.Taking the hydraulic valve and hydraulic cylinder as the object,the control model of the lifting device is established in AMESim.Fuzzy rules and related controllers are designed.The feasibility of PID and fuzzy PID control methods is verified from overshoot and response time respectively by Simulink tool.Simulation results show that when the optimal PID parameters are 100800,500 and 30,the response time of input signal is 0.55s.The response time of fuzzy PID control is 0.31s.After comparing and analyzing the control effects of fixed parameter PID control and fuzzy PID control under different disturbances,the overshoot of fuzzy PID control system is 0.84%,and the time required to reach steady state is 0.39s,which is less than 0.64s of fixed parameter PID control system.The method realizes the displacement control of the lifting device,improves the positioning accuracy of the cutter head,and improves the anti-interference and robustness of the control system.It provides reference for the precise control of cotton roof lifting device in cotton field environment.