Maize Test Bench And Its Control System For Single Longitudinal Axial Flow Threshing Cylinder

Maize is one of the largest grain crops in China,and the mechanization of maize harvest directly affects the yield and quality.Using maize grain harvester can increase the efficiency and reduce the energy consumption.It has great significance to product appropriate maize grain harvester machine.In such case,if we want to achieve the application,we should design and research maize threshing test bench first.In order to improve the standard of maize grain harvester in our country,this paper designs the maize test bench based on the former research,which is suitable for single longitudinal axial flow threshing maize grain harvester.Meanwhile,the software and hardware of the control system of the test bench are investigated.The main works and conclusions are as follow:(1)The mechanical structure design of single longitudinal axial flow maize threshing test bench: In this paper,the mechanical adjustment structure of the threshing cylinder and the main tunable parameters of the single longitudinal axial flow maize threshing experiment are studied,including the design of threshing cylinder,threshing elements,threshing cylinder roller angle adjusting component,adjusting mechanical structure of threshing gap,hollow plate and cover plate.And overall consumed power of threshing process is calculated and the appropriate motor is chosen on this basis.(2)Control system hardware design and research of threshing test bench: This paper selects the appropriate single chip microcomputer,stepper motor and other components to design the hardware control system.The hardware control system including design of single chip microcomputer circuit,speed regulation circuit,inclination adjustment circuit,gap adjustment circuit,TFT-LCD circuit,and stable voltage circuit etc.On the basis of the circuit design,the printed circuit board is made,the components are welded,and the hardware circuit of the control system is finished.(3)Control system algorithm and software design and research of the threshing test bench: The control system algorithm and software part of the threshing test bench are designed,including algorithm and software design of maize breakage rate signal acquisition,speed adjustment,design of inclination adjustment,gap adjustment,and TFT-LCD.After that,C Language is applied in Keil software to realize the algorithm.(4)The model verification and physical verification of the threshing test bench control system: The test bench control system verification model can be manufactured through the hardware and software design.In the laboratory conditions,various parameters that may appear during the test are verified by the control system.The verification shows that the design of software and hardware of the control system meet the requirements.If the grain crushing rate does not meet the requirement(less than 5%),the speed,clearance,and inclination can be adjusted ranging from 420r/min to 1020r/min,from 30 mm to 70 mm and from 5°to 15°respectively.During the process of physical verification,the operation of the test bench is stable,which means the prospective adjustment can be achieved.The test bench can adjust parameters under the control of control system.In this paper a single longitudinal axial flow threshing maize test bench is designed and tested,the corresponding control system is developed,and the control system is verified by experiments,which lays a foundation for the subsequent research of the single longitudinal axial flow maize threshing test bench.