| Pest and disease problems are particularly serious in the high temperature,high humidity and confined greenhouse environment,and effective control measures are needed to ensure the growth and quality of crops.In order to achieve a better control effect,high frequency spraying is often required.However,the traditional spraying operation in greenhouse is still mainly manual,which has problems of low efficiency,difficult to separate human and medicine,and high randomness of spraying,and the existing plant protection machinery has low specialization,single structure,and low utilization rate of liquid medicine.In this paper,we designed a greenhouse spraying robot with variable distance and height adjustment and automatic target spraying,mainly using the method of fitting the model of plant height and leaf outreach distance to optimize automatic target spraying and propose a segmented spraying method;by designing an on-track correction device and an auxiliary positioning By designing on-track correction device and auxiliary positioning device,the accuracy of rail alignment and upper and lower rails can be improved.The research content of this paper was determined by considering the demand of greenhouse crop spraying operation and combining with the characteristics of existing continuous glass greenhouse vegetable growing environment.The main research contents and conclusions are as follows:(1)To determine the main technical parameters and design scheme of the continuous greenhouse spraying robot for the spraying operation demand of the continuous greenhouse.Combining the construction characteristics of the continuous greenhouse and the agronomic requirements of vegetable cultivation,the overall design of the mobile chassis and spraying device separated spraying robot is proposed.Using the walking paths and insulation pipes laid between the rows in the continuous greenhouse,a "road-rail" operation method is proposed to meet the requirements of efficient operation of the spraying robot in the rows.(2)Adopt the modular design scheme to design and optimize the key functional components.The modeling of the bi-directional moving,segmented spray bar structure and anti-shaking device is carried out by Solid Works software,and the nozzle type is determined to be 110° fan and the nozzle spacing is 78cm;the models of key components in the water supply regulator are determined,and the water supply regulator scheme based on PWM technology is designed,and the correspondence between the pump pressure and PWM duty cycle is determined through the pump pressure test;the advantages and disadvantages of multiple wheels are compared,and the single-sided track wheel is determined.By comparing the advantages and disadvantages of various wheels,the single-sided track wheel is determined as the walking wheel on the track,and the universal wheel is determined as the supporting wheel.In order to ensure the stability of the continuous greenhouse spraying robot in the track operation,the design and installation of on-track correction device,and through the correction test to determine the best installation distance between the correction device and the insulation pipe is 2.2mm.(3)Design and analysis of the control system of the continuous greenhouse spraying robot.The information of plant height and leaf extension distance is recorded and the corresponding model is established to improve the accuracy of segmental spraying;the noise interference time generated by the hanging vine rope is determined to be 22 ms through the noise acquisition test,and the height determination algorithm is optimized;the displacement relationship between the central driving slide and the wire track slide is obtained through the simulation of the translational spray bar structure,and the mapping relationship between the filament slide and the output pulse is determined;based on the greenhouse Based on the greenhouse operation environment,the scheme of sweeping and positioning in the greenhouse is proposed,and the road markers and the size of the markers are determined;the road positioning auxiliary module is designed to optimize and improve the accuracy of the alignment and upper track;the MCGS embedded configuration software is used to design the operation interface of the MCGS terminal control system and optimize the operation logic of the terminal control system.(4)Prototype fabrication and performance optimization.The key components were selected and the prototype was fabricated according to the 3D design drawing,and the prototype was tested for performance,including multi-factor performance optimization test and spray uniformity test.The best combination of operating parameters was determined through the multi-factor performance optimization test: the operating speed was 0.4m/s and the spray pressure was 5bar;the spray uniformity test determined the spray uniformity of the prototype with a coefficient of variation of 11.25%,which met the spraying operation requirements in the greenhouse. |
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