| Precision agriculture and green ecology are fundamental issues related to the national economy and people’s livelihood,so vigorously developing agricultural production research of low-volume + agriculture + green has been required by national conditions.Lacking of intelligent spray machinery and equipment has become the key to restricting the development of this field in China.In order to promote the development of intelligent pesticide application machinery,it conforms to the needs of national agricultural development.In this paper,a small plant protection spray robot with adjustable spray height is designed to achieve low-volume and accurate application operations in agricultural facility scenarios such as greenhouses.The main research works are as follows:(1)According to the design requirements of the spray robot,the design of the chassis structure of the plant protection spray robot is realized.Walking mechanism of four-wheel two-wheel drive,chain drive,and differential steering was determined and the size and model of key components such as motors,chains,frame materials,vehicle structures,and spray frame bodies were selected.A three-dimensional model of the vehicle was established,and the model was imported into Abaqus software and Aadms software to analyze the robot’s frame force and kinematic simulation analysis in different environment.The results verify that the maximum gravity that the robot frame can withstand is 2700 N,which is much larger than the static stress of the spray system that the robot needs to withstand.And the design of the chassis can be stable on a 30 ° slope,with 60% climbing capacity.(2)Completed the design of the low-volume spray system.The spray system was designed with a gas-assisted nozzle and the indoor test of the spray system was conducted using the hydraulic nozzle as a control.Experimental results show that in the droplet particle size test,the distribution span of the air-assisted nozzle is reduced by 27.8%compared with the hydraulic nozzle.In the uniformity test,the coefficient of variation value of the air-assisted nozzle and the XR8001 nozzle was approximately 6.8%,which was 18%lower than other hydraulic nozzles.In the deposition coverage test,the deposition coverage of the air-assisted nozzle was increased by 0.8 times,1.53 times,0.47 times and 0.95 times compared with the hydraulic nozzles XR8001,HCC8001,TR8001 and KZ8004,respectively.(3)According to the control needs of the robot,the hardware circuit and software program of the motor drive module,the remote control handle control module and the relay control module are designed.On the basis of the completion of the hardware and software design,the performance test of the vehicle speed and relay was carried out.The results determined that the maximum travel speed of the robot was 5.04km/h,and the application time of the spray system could be controlled.(4)On the basis of the completion of the design of the control system,a test platform was built and and vehicle simulation tests were conducted on unstructured roads.The robot is controlled by the handle to carry out the deposition coverage test,and the message transmitted by Beidou.The results confirm that the robot can turn smoothly on unstructured roads with a row spacing of 60 cm.The working area of the spray system is increased by29.4% compared with the traditional hydraulic nozzle,the working deposition efficiency is increased by 23.55%,and the amount of droplet loss is reduced by 92.14 ml.The effective utilization rate of fog droplets has been significantly improved,and the design of the plant protection spray robot meets the expected requirements. |
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