Design And Experiment Of A Striped Aerial Sowing Device For Oil Rape And Rice

The UAV(Unmanned Aerial Vehicle)works with high efficiency and strong terrain adaptability.In order to better use its performance to enhance the unmanned level in the crop planting process,this dissertation explores and designs a strip aerial seeding device for oil rape and rice,which can be carried on a conventional six rotor UAV platform and can achieve seed sowing and landing into strips.This provides a new approach for efficient and precise mechanized direct seeding of rapeseed and rice,as a beneficial supplement to the existing ground sowing machinery in the rice-oil rape rotation area.With the design goals of dual-use,lightweight,electric drive,and modularization,this article focuses on the scheme design,structural design,experimental trial production,and parameter optimization of external groove wheel seeding and seed guide tube seeding.Following the basic technical route of"research status and agricultural research-goal formulation-scheme determination-prototype trial production-trial inspection-effect evaluation-scheme optimization",this article designs,trial produces An external groove wheel precision seeding system suitable for aerial seeding of rice and rapeseed was tested,specifically involving a dual purpose seeder with"external groove wheel quantitative seeding+mechanical/rotational speed seeding rate adjustment",a foldable seed guide device,and a flight control based control system.The main content is as follows:(1)A dual purpose oil rice seeder was designed and validated,which combines external groove wheel quantitative seeding with mechanical/rotational speed seeding rate adjustment.In order to achieve the design goals of lightweight,high adaptability,high reliability,and high-speed seed metering,a design scheme of external groove wheel seed metering and brush cleaning seed has been determined.Two common rice seeds,Jiangdao 501,Huanghuazhan,and a common rapeseed seed,Huayouza 62,were selected as the basis for the design and calculation of the seeding wheel.To ensure the reliability of the seeding when using a low torque drive motor,it is proposed to design a 28°drag reduction slope at the initial position of the seeding,and a drag reduction plan of designing a seed guard plate above the seed filling chamber after calculation,The JGB37-520 DC reduction motor with a rated torque of 0.45 N·m can meet the driving requirements;According to the selected reference seed parameters,design and calculate the external groove wheel,and finally determine that the cross-section of the external groove wheel seed arrangement wheel is a right angled trapezoid,with a trapezoidal groove opening width of 11 mm,a bottom width of 5 mm,and a depth of 6mm.At this time,the groove area is 48 mm~2,the diameter of the seed arrangement wheel is 67 mm,the distribution angle of the groove is 20°,and the number of grooves is 18;To ensure the smooth entry of seeds into the seeder,a seed inlet slope of 30°is designed at the inlet,and the height of the inlet opening is 20 mm.(2)On the basis of simulating and analyzing the mixed airflow field beneath the six rotor UAV platform,an automatic folding seed guide tube folding device was designed.Through the ANSYS Fluent simulation analysis module,it was found that the mixed airflow field below the six rotor UAV platform tends to shift towards the rear of the fuselage along the direction of motion when the UAV is flying.At a flight speed of3 m/s,the vortex generated by the forward rotor airflow ruptures,and the overall mixed airflow field shifts towards the rear of the fuselage,and the degree of migration increases with the increase of flight speed;At-1 m below the UAV body,the mixed airflow field deviates from the central axis of the body,and the faster the speed,the higher the degree of deviation.Based on this,a seeding plan is determined to use a seed guide tube to extend the seeding position out of the mixed airflow field.The specifications of the seed guide tube are outer diameter 20 mm,inner diameter 18 mm,and length 50 cm.To ensure normal take off and landing,the steering engine is used to drive the connecting rod to fold the seed guide tube,and the SPT5425LV high torque steering engine with a rated torque of 2.5 N·m is used to drive the steering engine.Furthermore,based on the ANSYS Work Bench transient analysis module,dynamic simulation analysis was conducted on the stress-strain state of various components of the seed guide tube folding device during operation.(3)Based on the reserved peripheral ports for flight control,a control system for the integrated aerial seeding system was designed.Based on the characteristics of the strip aerial seeding operation,the control system requirements are analyzed to determine the speed and angle position control requirements of 12 drive motors for the 6-row seeding system,2 types,and 12 types of the strip aerial seeding device.By analyzing the UAV flight control system and the number of remote control receiver channels for flight control system,a control scheme based on polar wing K++V2 flight control system and Yunzhuo T12 remote control and receiver is proposed,and supporting wiring connection circuits are designed.The experiment shows that the control system can meet the synchronous control requirements of multiple motors and operate stably and reliably.The speed regulation function of the seeder can meet the common sowing requirements of two crops.(4)From the perspective of parameter optimization and scheme validation,a series of strip forming aerial experiments and data analysis were conducted.Gradually determine the structural and working parameters of the strip air seeding device through three methods:bench test,field mud box test,and field test,and verify the operation effect.The experiment shows that within the rated speed and torque range of the seeding motor,the seeding system can meet the agronomic requirements of rapeseed 400-500 g,hybrid rice 1-3 kg,and conventional rice 4-7 kg per mu at a flight speed of less than 5 m/s.Moreover,the performance parameters such as coefficient of variation for consistency in each row and coefficient of variation for total displacement are better than industry standards.When the operating height is 1 m and the operating speed is 4 m/s,The average width of the seed strip in the mud box is 6.7 cm for rapeseed and 3.8 cm for rice.The field experiment was conducted using the best operating parameters in the field experiment,and the effect of seedling formation in the field was significant 30 days after sowing.