玉米联合收获机脱粒清选监控系统研究

发布时间：2018-12-18 03:07

【摘要】：脱粒清选装置是玉米联合收获机的关键装置,决定着收获机的作业性能和效率。由于受到恶劣且多变的田间环境的影响,脱粒清选装置的工作性能无法充分发挥,籽粒破碎率和损失量较高,且极易发生滚筒堵塞等故障现象。本文针对脱粒清选装置工作过程中非线性、时变且滞后的特点,分析影响脱粒清选效果的主要因素。在此基础上,以PLC为核心控制器,触摸屏为监测和控制界面,开发脱粒清选监控系统,对关键参数进行监测和预警,对液压执行元件参数进行调整,通过模糊控制得到作业速度改变量,对行走速度进行调整,使得脱粒清选装置在保证可靠性的前提下充分发挥工作性能。研究脱粒清选原理,对影响脱粒清选效果的主要因素进行分析,主要包括滚筒转速、脱粒间隙、喂入量、籽粒含水率、风机风量与出风口倾角、清选筛箱振动频率与幅度、鱼鳞筛开度等,针对这些影响因素,确定监测量和控制量,制定脱粒清选监控系统总体方案。研究模糊控制原理和模糊控制算法,设计以滚筒角速度偏差和偏差变化率为输入、收获机行走速度变化量为输出的脱粒滚筒二维模糊控制器,结合实际操控经验制定模糊推理规则,建立模糊控制查询表,采用模糊控制算法对脱粒滚筒负荷进行控制。针对监控系统方案进行硬件设计,主要包括水分传感器、压力传感器、动态扭矩传感器选型及布置,收获机行走速度、滚筒转速、风机转速、筛箱驱动转速等关键转速检测及调节,脱粒间隙检测及调节,根据系统需求对PLC与触摸屏进行选型,并对PLC输入输出端子进行合理分配。针对监控系统流程进行软件设计,主要包括数字量和模拟量传感器采集关键参数的梯形图程序,控制液压执行元件的梯形图程序,实现模糊控制算法的梯形图程序,开发触摸屏,设计初始参数设置、关键参数采集及显示、液压执行元件控制及报警等人机交互界面。运用MATLAB Fuzzy Logic Toolbox设计脱粒滚筒模糊控制器,通过Simulink对滚筒模糊控制进行建模并仿真,结果证明了应用模糊控制算法对滚筒进行负荷控制的正确性和可行性;搭建脱粒清选监控系统实验台进行实验,模拟各关键参数的采集、监测及预警和各液压元件的控制,证明了所开发的监控系统的合理性和有效性。
[Abstract]:Threshing and cleaning device is the key device of corn combine harvester, which determines the performance and efficiency of the harvester. Because of the bad and changeable field environment, the working performance of the threshing and clearing device can not be brought into full play, the breakage rate and the loss amount of grain are high, and the fault phenomena such as drum clogging are easy to occur. In view of the characteristics of nonlinearity, time-varying and lag in the working process of threshing and cleaning device, the main factors influencing the threshing and cleaning effect are analyzed in this paper. On this basis, with PLC as the core controller and touch screen as the monitoring and control interface, a threshing and cleaning monitoring system is developed. The key parameters are monitored and forewarned, and the parameters of hydraulic actuator are adjusted. The operating speed is changed by fuzzy control and the walking speed is adjusted so that the threshing and cleaning device can give full play to its working performance under the premise of ensuring the reliability. The principle of threshing and cleaning is studied, and the main factors influencing the effect of threshing and cleaning are analyzed, including drum speed, threshing clearance, feed quantity, grain moisture content, fan air volume and outlet inclination angle, vibration frequency and amplitude of cleaning and screening box. In view of these influencing factors, the monitoring quantity and control quantity were determined, and the overall scheme of threshing and cleaning monitoring system was established. The fuzzy control principle and fuzzy control algorithm are studied. A two dimensional fuzzy controller for threshing drum is designed, which takes the angular velocity deviation and deviation rate as input and the speed change of harvester as output. The fuzzy inference rules are formulated based on the practical operation experience, the fuzzy control query table is established, and the threshing drum load is controlled by fuzzy control algorithm. The hardware design of monitoring system includes water sensor, pressure sensor, dynamic torque sensor selection and arrangement, harvester walking speed, drum speed, fan speed, etc. The key speed of screen box driving speed and so on are detected and adjusted, the threshing clearance is detected and adjusted, the PLC and touch screen are selected according to the system requirement, and the input and output terminals of PLC are allocated reasonably. According to the software design of the monitoring system, it mainly includes the trapezoidal diagram program of digital and analog sensor collecting key parameters, the trapezoidal diagram program of controlling hydraulic executive element, and the trapezoidal diagram program of fuzzy control algorithm. Develop touch screen, design initial parameter setting, key parameter acquisition and display, hydraulic actuator control and alarm man-machine interactive interface. The fuzzy controller of threshing drum is designed by MATLAB Fuzzy Logic Toolbox, and the fuzzy control of drum is modeled and simulated by Simulink. The results show that the fuzzy control algorithm is correct and feasible. The experiment bench was built to simulate the collection, monitoring and warning of the key parameters and the control of the hydraulic components, which proved the rationality and effectiveness of the developed monitoring system.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S225.51;TP277

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