摘要
【目的】为了满足复杂农林环境下植保喷雾作业需求,需要解决喷雾机底盘电液作动器采用传统PID(propor-tional integral differential)控制器控制参数难以自适应调整,以及模糊PID混合控制器难以制定切换策略的难题。【方法】建立了电液作动器系统的几何模型、数学模型和物理模型,采用有限单元法对其进行了结构静力学分析和优化设计;采用正开口三位四通电磁比例换向阀作为控制元件,设计了模糊PID控制器,并采用MATLAB/SIMULINK进行了控制器建模和仿真,比较了3种控制器的控制效果。【结果】将底盘两横轴直径分别增大10 mm,电液作动器液压缸和活塞杆直径分别增大5 mm,横轴和电液作动器的最大变形量分别减小到4.6 mm和1.1 mm,可满足底盘支撑强度要求;采用模糊PID控制器控制电液作动器比其他两种控制器有更好的综合特性,其上升时间、调整时间、绝对累积误差和绝对时间累积误差在电液作动器上升运动和下降运动中的取值分别为0.099、0251、0013、0005 s和0088、0267、0009、0013 s,模糊PID控制器的多项控制指标值均有较明显降低。【结论】模糊PID控制器用于喷雾机底盘电液作动器的位置跟踪控制有更高的控制精度和更快的响应速度。
[ Objective] To protect plants from attacks of bacteria and fungi, there is a need to accurately control spray operation under complex agricultural and forestry environments. To solve the major problem are that the parameter of a traditional proportional integral differential（ PID ）controller is not self-adaptive to the position error, and the hybrid fuzzy-PID controller with coupled rule （HFPIDCR） is difficult to plan in it＇s switching scheme in electro-hydraulic ac- tuator （EHA） system of the sprayer chassis. [ Method] The geometric, physical and mathematical model of the EHA sys- tem were developed. Structural static analysis and optimization design were performed with the finite element method. An underlapped three-position four-way proportional valve was selected as the control component and a fuzzy PID controller was designed. The controllers were established and simulated with MATLAB/SIMULINK. Control effects of three kinds of controllers were compared. [ Result] If the two horizontal axis diameters of chassis are increased by 10 mm while cylinder and piston rod diameters of EHA are increased by 5 mm respectively, then the maximum deformation of the horizontal axis and EHA are reduced to 4.6 mm and 1.1 mm respectively. The chassis supporting strength requirements are satis- fied. The rising time, settling time, integral absolute error （IAE） and integral time absolute error （ITAE）of the fuzzy PID controller are 0.099, 0.251, 0.013 and 0.005 s in upward motion and 0.088, 0.267, 0.009 and 0.013 s in down- ward motion, respectively. Comparing to the traditional PID and HFPIDCR controller, the proposed fuzzy PID controller has better comprehensive characteristics and the various control index values are significantly lower. [ Conclusion ] The fuzzy PID controller has more rapid response and higher control accuracy in the position tracking control of EHA system of a sprayer chassis.
出处
《南京林业大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第1期163-169,共7页
Journal of Nanjing Forestry University：Natural Sciences Edition
基金
江苏省农机"三新"工程项目(NJ2014-11)
江苏省科技支撑计划-农业高技术专项(BE2012383)
安徽省科技厅科技攻关计划项目(1501031095)
江苏高校优势学科建设工程资助项目(PAPD)
关键词
柔性底盘
电液作动器
模糊PID
位置跟踪
植保喷雾作业
flexible chassis
electro-hydraulic actuator
fuzzy PID
position tracking
plant protection spray operation
