Design and tests of a rotary plug seedling pick-up mechanism for vegetable automatic transplanter

The rotary plug seedling pick-up mechanism for vegetable automatic transplanter is the technical bottleneck to improve the mechanization level of vegetable planting in China.In order to solve the problems of rotary seedling pick-up mechanism proposed in previous study,such as low success ratio of seedling pick-up at high speed,and interference between the seedling bowl and the end of the other seedling pick-up arm,a novel kind of rotary seedling pick-up mechanism of planetary gear train with combined type gears of incomplete denatured-eccentric-circular and non-circular gears was proposed.Through kinematic analysis of the seedling pick-up mechanism,the kinematics model was established.The computer-aided analysis and optimization software with human-computer interaction method was developed to realize parameters optimization of the seedling pick-up mechanism.Three-dimensional parametric design system of seedling pick-up mechanisms with combined non-circular gear transmission was developed for mechanism virtual simulation to verify the correctness of theoretical model and design results of the mechanism.The physical prototype of the mechanism was manufactured,and high-speed camera kinematics tests of the mechanism were conducted in the laboratory to study its kinematic characteristics.Laboratory seedling pick-up tests were carried out.The mechanism has the success ratio of seedling pick-up 96.3%without interference during seedling transporting when the rotation speed of the mechanism is 50 r/min and the seedling transplanting efficiency is 100 plants/min per row,showing that the novel mechanism has better working performance than the original one and could be applied in vegetable plug seedling transplanter.

Design and optimization of seedling-feeding device for automatic maize transplanter with maize straw seedling-sprouting tray

This research aimed to solve current problems in the process of maize transplanting in China such as large labor intensity,low working efficiency and poor quality.On the basis of the structure of a seedling-sprouting tray made of maize straw and the agronomic requirements of maize production,this study developed a new feeding device for such a sprouting tray,determined the dimensions of the key components in a virtual environment via Solid Edge software and obtained optimal working parameters in combination with Matlab.Some tests on field validation and maize production were conducted as well.The test results showed the importance of the working parameters on an upright degree in descending order(as well as the best working parameters)to be the vertical angle of seedling planting(13.14°),the forward speed of locomotion(0.57 m/s),and the horizontal angle of the seedling box(22.5°).The standard deviation of the field validation was 6.04%,which was within the allowable range to meet the requirements of maize transplanting.Compared with maize transplanting machines(and manual transplanting operations)on the current market,the labor inputs,as well as the rates of spacing and upright degree qualification,omitted planting and the yield using the new feeding device for automatic transplanter with maize straw seedling-sprouting trays increased 0(6.9%),0(3.1%),0(4.5%)and 0(−1.0%),respectively;whereas,the manufacturing cost was reduced by 35.5%.The results can provide a technical basis and reference for subsequent development of automatic transplanters with maize straw seedling-sprouting trays.

Design and testing of the mechanical picking function of a high-speed seedling auto-transplanter

To improve the low transplanting efficiencies and simplify the complex structures of current automatic transplanters,a mechanical high-speed transplanter for picking plug seedlings that is suitable for planting on plastic filmswas designed.Themain components were an automatic seedling picking systemand a basket-type planting system,whichwere used for the following processes:automatic picking,planting,soil covering,and suppression of plug seedlings.The performance test was performed on the automatic transplanter with 60-day-old pepper seedlings.The transplanting efficiency was tested at speeds of 40,60,90,and 120 plants·min−1.The results showed that the coefficient of variation(CV)of the plant spacing and the missed transplanting rate increased with the planting frequency,whereas the qualified rate of planting perpendicularity and the qualified rate of planting decreasedwith the increase in the planting frequency.All planting indicesmet the JB/T 102912013 standards.The results of this study showed that the auto-transplanter could performhigh-speed transplanting on the basis of completing the following functions:automatic picking,planting,soil covering,and suppression of plug seedlings.

Development of single row automatic transplanting device for potted vegetable seedlings

In China,low degree of automation seriously affects the working efficiency and quality in vegetable transplanting.As one of the most important vegetables in China even in the world,tomato was taken as the research object in this study.An automatic single-row transplanting device was designed,based on the statistical analysis of the physical and mechanical properties of tomato seedlings of a typical variety.Based on the technology of mechatronics,the device integrated the functions of transporting seedling tray,automatic seedling extraction and mechanical planting.The kinematics orthogonality solution combined with the dynamic sequence solution method was used to optimize and analyze the kinematic parameters of the automatic seeding mechanism,and the“sickle”trajectory was obtained.According to the position and movement requirement for taking and dropping seedling,the mechanical conditions and the working parameters of key execution parts were obtained by using analytic drawing method to analyze the mechanical condition of seedling collecting mechanism.The transplanting experiment was conducted at room temperature of 25°C,and the age and moisture content of the seedlings were 40 d and 55%,respectively.The results showed that the highest success rate was 92.59%,and the lowest rate of leakage was 23.13%,when the transplanting frequency was 60 plants/min.The lowest success rate was 77.78%,and the highest rate of leakage was 38.75%,when transplanting frequency was 120 plants/min.When the transplanting frequency is between 60-90 plants/min,the device can meet the requirement of high speed transplanting for potted vegetable seedling.

Potential analysis of an automatic transplanting method for healthy potted seedlings using computer vision

Healthy seedlings transplanting is an important process in the production of vegetables and economic crops,and the transplanting quality directly affects crop yield.Automatic seedlings transplanting can improve the transplanting efficiency of seedlings.We developed a physical prototype of potted seedling automatic transplanting with a conveyor and a transplanting end-effector in the previous study.This work proposed an automatic transplanting method of healthy potted seedlings,which mainly included a detection part of seedlings growth status and a visual servo control part with the purpose of automatic transplanting seedlings high-efficiently.The seedlings and the tray cell were simultaneously detected for identifying healthy seedlings,damaged seedlings and empty cells using a machine vision algorithm when the tray was moving on the conveyor line.The visual servo model was applied to enable the collaborative operation of the machine vision and the end-effector for determining the position and attitude of grasping seedlings.The experimental results showed that the accuracy rates of the identification of empty tray cells,healthy seedling and unhealthy seedling were 96.42%,98.77%and 89.95%,respectively.Under the successful identification of the healthy seedling,the accuracy rate of grasping seedling was 96.38%.It implied that our proposed method can effectively transplant seedlings.