Design And Experiment Of Small Plant Spacing Planting Device Of Tuber Mustard Based On Mechanical-Crop-Soil Coupling Model

Yuyao city,Zhejiang Province is a famous production and processing base of tuber mustard.Locally,tuber mustard is a densely planted crop,requiring planting spacing of 12 ～14 cm.Because of the lack of close planting transplanting machine in the domestic market,so in the transplanting link is still manual operation.Manual operation has problems such as high labor intensity,low efficiency and non-standard planting,and with the rise of labor costs,the production cost becomes higher,resulting in the final benefit is not obvious,thus reducing the enthusiasm of farmers to produce,hindering the further development of local mustard industry.Therefore,this paper studies a planting device for transplanting tuber mustard with small plant spacing.The main research contents are as follows:(1)According to the requirements of planting and agronomic technology of pickled mustard,a planting device is designed as the core working part of transplanting machine.The planting device is analyzed theoretically by establishing its kinematic mathematical model.Then,according to the mathematical model,the parametric model of the planting device is established in ADAMS software.By optimizing the trajectory curve of planting point,the optimal structural parameter combination is obtained which is in line with the requirements of the planting of tuber mustard seedlings.Finally,according to the determined structural parameters,the three-dimensional model design of the planting device is completed in Solid Works software,and the simulation analysis is carried out in combination with ADAMS software.(2)In this paper,the coupled method of EDEM-ADAMS software will be used to simulate the whole process of the transplanter planting tuber mustard seedlings,so as to study the mechanism of mechanic-crop-soil interaction,but the premise is to determine the discrete element parameters of the simulation model of tuber mustard seedlings and soil particles.Therefore,in order to establish the simulation model of tuber mustard seedlings,the physical and mechanical characteristic parameters of Yongzha No.2 and Yongzha No.4 tuber mustard seedlings are measured,and the discrete element parameters of tuber mustard seedlings are calibrated with Yongzha No.2 as the representative.At the same time,in order to establish the simulation model of soil particles,the intrinsic physical parameters of soil are measured and the discrete element parameters of soil particles are calibrated.(3)Through the method of EDEM-ADAMS software coupling,the whole process of the transplanter planting tuber mustard seedlings is simulated.Firstly,the coupling simulation model of planting device is set up in ADAMS and EDEM respectively.Then,according to the discrete element parameters determined earlier,the simulation model of tuber mustard seedling and soil particles is established in EDEM software.Finally,through coupling simulation,the mechanism of mechanism-crop-soil interaction is analyzed,including changes in the pose of tuber mustard seedlings,disturbance of soil particles and changes in the force of the planter.The results showed that the planter had a certain righting effect on tuber mustard seedlings,and the upright degree of transplanted tuber mustard seedlings is higher.From planting device into the soil to planting seedlings and then to leave the soil,there is a certain disturbance to the soil.After the planting device leaves the soil,a certain size of the hole is formed,but with the return of soil particles,the hole is reduced.Soil particle return has a certain role in ensuring the effective planting depth of tuber mustard seedlings and stabilizing the upright posture of tuber mustard seedlings.The interaction forces among the duckbill planter,tuber mustard seedling and soil are analyzed.The results show that the maximum loads on the left and right sides of duckbill are 11.51 N and 11.70 N,respectively,and the soil breaking of the planter is easy.The maximum loads on the left and right duck bills rae 0.91 N and 1.06 N,respectively,when they are only in contact with the seedlings,and no seedling damage will occur.(4)The processing of the planting device is completed,and the whole transplanter is assembled,and then field experiments are carried out on two varieties of pickled mustard seedlings Yongzha No.2 and Yongzha No.4.The quality of transplanting machine was analyzed statistically according to the evaluation indexes of transplanting,such as leakage rate,injury rate and upright degree.According to the data analysis,the leakage rate and seedling injury rate of the two varieties are lower,both below 5%.The qualified rate of planting depth is higher than 95%.The transplanting qualified rate is higher,reaching 90% and above,the transplanting excellent and good rate of Yongzha No.2 is 86%,and the transplanting excellent and good rate of Yongzha No.4 is 88%.The average plant spacing was about 130 mm,and the coefficient of variation of plant spacing was small,indicating that the transplanting machine had good applicability and stable operation performance,which could meet the agronomic requirements of small plant spacing planting tuber mustard.At the same time,this paper provides a reference for the research and development of the transplanting machine for other dense crops such as capsicum and Shanghai Green.