| Single Longitudinal Axial Flow Corn Combine Harvester,the author of this paper due to the complexity of operation control system and cause the work quality and efficiency of low problem,combined with the combine harvester in threshing cylinder rotation speed and the development trend of concave plate gap size control,working parameters monitoring device development present situation,design a new intelligent control system.The optimal working parameters were obtained by the corn harvesting experiment and treatment analysis under three specific influencing factors of working place,working time and crop moisture content.The system adjusted the speed of threshing drum and the gap size of concave plate in real time by referring to the optimal working parameters.Hydraulic proportional control technology is used in the design of drum speed regulation system,motor control technology is used in the design of concave plate clearance regulation system,PLC as the core controller,PID algorithm is used for real-time regulation.Through relevant simulation can prove that: operators only need to work in the system time,moisture content of crops,crop varieties and plant intensive four factors are set,the machine that can work for the optimal working parameters(roller speed 300 r/min,concave plate gap 30.94 mm),reduce the grain broken rate to 0.095%,and the system has high stability,accuracy and rapidity.The main work and achievements of this paper are as follows:(1)Analyze the working principle of John Deere combine harvester.It includes a brief description of the whole transmission route of the combine harvester;The whole hydraulic system of the machine is briefly analyzed and the control principle of the original system is clarified.This paper analyzes in detail the infinitely variable speed part of the threshing drum in the hydraulic system,and determines the important parameters such as the working pressure of the hydraulic system and the displacement of the hydraulic pump.The relation between the elongation of hydraulic cylinder and the change of rotating speed of cylinder is determined.The clearance adjusting device of concave plate on the original machine was analyzed in detail and the range of clearance adjusting was determined.(2)Mechanical design of combine harvester control system.According to the design requirements,the control scheme is worked out,and the hydraulic components are selected by relevant calculation.(3)The dynamic model of hydraulic proportional control system of threshing drum is established.Firstly,the transfer function of the control element and the executing element is calculated,the transfer block diagram of the whole hydraulic system is determined,the relevant parameters of each transfer function are calculated and the transfer function of the whole system is determined,the system is simulated by Matlab software,and the mathematical model of the system is analyzed.(4)The electrical control system of combine harvester is designed.According to the control requirements to determine the design scheme,PLC,touch screen and other electrical components selection,set up the overall electronic control system;The control algorithm for adjusting the speed of the roller and the gap of the concave plate was designed,and the related software program was written to further improve the control system.(5)Control system model verification and physical verification.The corn harvesting experiment was carried out on the original machine under three specific influencing factors: working place,working time and crop moisture content.The hydraulic system of threshing drum was simulated by Amesim simulation software,and the feasibility and followability of the system were preliminarily demonstrated. |
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