| At present,vegetable planting machinery in China is mainly small and semi-automatic.Automatic transplanting machine is difficult to be popularized in a wide range because of its high price and single planting variety.With the decrease of agricultural population and the increasing demand for vegetables in China,it is urgent to develop a general automatic vegetable transplanting machine.Therefore,this paper designed a universal automatic seedling feeding device matching with Jingguan PVHR2-E18 semi-automatic vegetable transplanting machine,which replaced manual seedling feeding with machinery to realize automatic transplanting operation,and could be applied to various specifications of plugs for operation.In this paper,the key technologies are studied,and the relevant theoretical analysis and prototype test are carried out.The research results can provide reference for the development and development of automatic general vegetable transplanter.The main research contents of this paper are as follows:(1)Determine the overall structure scheme of general automatic seedling feeding device for vegetable transplanter.The overall structure of general automatic seedling feeding device is designed based on Solid Works software,and its working principle is expounded.By surveying and mapping the whole parameters of PVHR2-E18 vegetable semi-automatic transplanting machine,the size parameters and installation mode of the supporting seedling feeding device were determined.(2)Complete the structure design and simulation analysis of general seedling feeding parts.Eight feeding claws are fixed on the general feeding parts,and the feeding method of whole row grasping and variable distance seeding is realized by using the specific track on the feeding plate.By establishing the mathematical model of the trajectory of the seedling feeding plate,three parameters affecting the trajectory were selected,and the Box-Behnken central composite design experiment was carried out.The experimental results were obtained based on ADAMS simulation,and the trajectory optimization was completed.(3)Complete the design and optimization of feeding claw and auxiliary parts.Through the force analysis of the seedling lump,the motion mathematical model of the seedling claw is established,and the structural optimization design is completed.The strength of seedling needle was checked based on ANSYS,and the motion trajectory of seedling needle was obtained based on ADAMS to complete the rationality test of feeding seedling claw.The structural design of the pressure plate mechanism was completed by spring selection and pressure check of the plug seedling plate.The structural design of Y-type plate changer was completed by analyzing the locking motion process,and the cylinder stroke,installation position and the length of connecting rod were determined.The model of synchronous belt module and stepping motor of horizontal moving parts were determined by theoretical calculation.(4)Complete the hardware and software design of the control system.The domestic Xinjie PLC was selected as the host of the whole machine control system for the selection of cylinders,air compressors and sensors.The selection of hardware in the control box and the installation and wiring were completed.The software design of the control system was completed,and the equipment was debugged to meet the control requirements of the general automatic seedling feeding device.(5)Experimental study on general automatic feeding device.Taking 72 tomato seedlings as the test object,the test index was determined as the success rate of seedling feeding.The test factors were the moisture content of seedling matrix,the inlet pressure of confluence plate and the seedling age of plug seedlings.Single factor test and triple quadratic regression combination test were carried out,and variance analysis and test of dominance and unfitness were performed on the experimental results.The optimal working combination was determined as follows : the moisture content of seedling matrix was 48.32 %,the inlet pressure of confluence plate was 0.38 MPa,the seedling age of plug seedling was 34.55 d,and the success rate of seedling feeding was 93.06 %. |
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