Design And Research Of Unmanned Harvesting System For Vegetable Trays In Facilitie

China is the largest producer and consumer of vegetables in the world.At present,people’s demand for fresh vegetables,especially leaf vegetables,is increasing year by year.Due to high labor cost and high vegetable price,the development of vegetable industry is affected.The key technology of efficient and green production of unmanned seedling of greenhouse vegetables is a new focus of modern agriculture and biological agriculture in China.However,the mechanization management level of greenhouse vegetables in China is relatively backward,and there is no relevant efficient vegetable seedling tray placing and collection equipment at present,which restricts the large-scale and efficient development of greenhouse vegetable seedling industry.Therefore,developing a set of system suitable for the unmanned placing and collecting of vegetable seedling tray in greenhouse is of great significance.This paper determines the overall system design and research scheme of this paper through the analysis of the demand for unmanned vegetable seedling tray placing and collecting in greenhouse.The research content includes structure design,hardware circuit design,path planning,magnetic field precise positioning and system software design.Firstly,in terms of structure,the functional requirements of unmanned vegetable seedling tray placing and collecting system are analyzed,and the selection and design of each functional module in the transportation robot and placing and collecting robot are carried out.The walking mechanism,placing and collecting mechanism and auxiliary devices for the unmanned placing and collecting system are developed to ensure that the robot can meet the requirements of structure and function.Secondly,the hardware control circuit of unmanned vegetable seedling tray placing and collecting system robots with STM32F103RCT6 as main control chip are designed,meeting the control requirements such as movement requirement and placing and collecting requirement.Thirdly,the grid map of environment and obstacle location updating strategy for greenhouse vegetable bases are established.According to the problems of local minimum and unreachable target in robot path planning,an improved artificial potential field method is proposed for unmanned placing and collecting system of vegetable seedling tray in greenhouse,and the path planning simulation and comparison are carried out.Fourthly,the theoretical derivation of the ground cylindrical permanent magnet magnetic field model for greenhouse vegetable base is carried out.The correctness of the theoretical derivation is verified by calculated value of the magnetic field model and the finite element simulation results.The magnetic field model is modified according to the error between the calculated and measured.Based on the modified magnetic field model,the magnetic force positioning model of ground cylindrical permanent magnet center and array magnetic field detection center is established.Finally,combined with the design requirements of the system,the main program of the upper and lower computer as well as the subprograms of the lower computer are designed.Charging,wireless communication,path planning,precise positioning and vegetable seedling tray placing and collecting functions are realized.To realize the control of the program,the touch screen interface is designed in the upper computer,and the prototype is tested..In this paper,the unmanned placing and collecting system of vegetable seedling tray in greenhouse is designed,and the requirement of automatic transportation of vegetable seedling tray in greenhouse is achieved,which can provide equipment and technical support for improving the intelligence of vegetable production by using vegetable seedling tray in China.