| Sowing operations are the most basic process in modern agricultural production and have an important impact on crop yields.In recent years,while the conservation tillage technology has been greatly promoted and applied,some problems such as rowing spacing inconvenient controlling and uncertain spacing result from the ground wheel slip appeared.At the same time,the quantity of small and medium sized seeders in the Huanghuaihai region of China is large;It is common for the seeders to demand to refit the seeders according to the requirement of different sowing spacing.On the one hand,this method can meet the requirement to a certain extent,it is poor in versatility,inconvenient operation and its operation or accuracy are not high;on the other hand,it is costly to buy a new seeder.In combination with the above problems,this paper designed a soybean seeder rowing spacing adjustment device based on the single chip microcomputer,which is suitable for the Huanghuaihai area.The working principle of this rowing spacing adjustment device is that use a single chip microcomputer as the main control chip,and use the ground wheel as a power source to drive seed metering device.The precise adjustment of the rowing spacing is achieved by changing the transmission ratio of the rowing spacing adjustment device,The DC stepping motor is coaxially connected with the screw adjustment mechanism of the rowing spacing adjustment device,DC stepping motor rotation can change the transmission ratio of the rowing spacing device;The rotary encoder is fixed on the power output shaft of the rowing spacing adjusting device through the shaft sleeve structure,and real-time monitoring of the power output shaft speed;The tool travel speed can be obtained through keyboard input and USB serial port input sensor speed measurement circuit and Beidou system data.According to the travel speed and skid rate of the implement,the control system can be used to adjust the power output shaft speed,control and realize the real-time adjustment of the rowing spacing and ensure the stability of seeding spacing.The project mainly completed the following work:1.Through consulting a large number of relevant references,combining with theactual situation in the Huanghuaihai region,we have designed a rowing spacing adjustment device based on the microcomputers,two-dimensional drawings,and three-dimensional drawings.made a prototype.Besides,A prototype was producted.2.Combining with the principle of curve fitting,establishing the relevant mathematical function models that the parameters of the screw rotation angle and rowing spacing adjustment device transmission ratio,screw rotation angle and seeding spacing needed inside the control system.3.The research and design of the control system hardware part of the rowing spacing device were completed.Combining the working principle,advantages,and disadvantages of various electronic components,completing the selection of each module and the design of the hardware circuit.So the control system circuit board was manufactured in the end.4.The research and design of the control systems software part of the rowing spacing adjustment system were completed.The program was programmed by C language.The programming includes the main program,speed subroutine,stepping motor driver subroutine and USB serial communication subroutine.5.The test and analysis of the rowing spacing adjusting device were carried out on the designed rowing spacing adjusting device.Through the speed control performance test and the rowing spacing controling test,collecting statistical test data,and analyzing the performance of the rowing spacing adjustment device.The speed control performance test result shows that the maximum error of rowing spacing adjustment device adjustment accuracy is 0.63%,0.63%,0.95%,and 0.95% when the slip ratio is 0%,10%,20%,and 30%.The ground wheel slip has no significant effect on speed adjustment errors,the speed adjustment error of the rowing spacing adjustment device increases as the rotational target speed of the power output shaft decreases,and the rowing spacing adjustment device adjustment has great accuracy and stability.When ground wheel slip,the rowing spacing control test result shows that the eligibility index is more than 90.05%,the replay index,leaky index and coefficient of variation are less than 5.28%,4.67% and 13.55% when the rowing spacing is less than or equal to 10 cm and more than 0cm.The eligibility index is more than 92.76%,the replay index,leaky index,and coefficient of variation are less than4.57%,2.67%,and 8.84% when the rowing spacing is less than or equal to 20 cm and more than 20 cm.There is no obvious relationship between the sowing operation effect of the rowing spacing adjustment device with the slip rate of the ground wheel,allworking indicators meet national standards and device can achieve precision seeding operations. |
PDF Full Text Request