Design And Study On System Of Pneumatic-picking Seedling For Aperture Disk Vertical Pick-up Device

Xinjiang’s tomato production capacity acounts for about 90% of the country’s, it’s exportion volume occupies a quarter of total world trade. Xinjiang has become the world’s third largest tomato base for production and exportion just after the United States and Italy. Instability in season heat resource of climatic characteristics in Xinjiang is an important factor restricting crop yields, Seedlings transplanting after the last frost plug can reduce the impact of natural disasters and make a compensation for the climate. The traditional manual transplanting seedlings of field agronomic process makes labor-intensive, has low productivity and some kinds of difficulty to achieve large-scale operations. Therefore achieving automation of plug crop transplanting seedlings has become an inevitable trend. Focuses on the problem of seedlings omission and injury during the process of the current automatic mechanization seedlings picking, this paper brings up a pneumatic seedlings picking system based on aperture disk vertical pick-up device. and designs of its key components after making the theoretical analysis, makes flow field analysis of the critical structure in pneumatic system, produces a physical prototype for the related experimental research.This paper studies the mechanism of jet impingement picking-up plug seedlings. In this process, measured the force required to break the knot of the seedling under different moisture conditions through experiment; completed the dynamics analysis and mathematical modeling in the three-phase of pneumatic seedling picking-up; built out the idealized model and divides the boundary of cavity flow field; solved the parametric equation of seedlings’ initial velocity in order to find various factors which effects the seedlings’ initial velocity using mathematical analysis software MATLAB and analyzed individually.So we reached the following conclusions: Initial nozzle airflow pressure is the most critical factor in the inpact of cast seedlings initial speed, followed by turbulence coefficient, plug inclination,ejected distance and nozzles radius have a certain impact on the initial velocity of cast seedlings. By control the environmental variables and pneumatic parameters we can achieve the ideal state of zero speed cast seedlings.this proved the feasibility of the ideal manner to cast seedlings--zero speed seedlings-cast.Then using three-dimensional modeling software Solid Works completed the overall design of pneumatic picking seedlings system, completed the design and selection of the seedlings picking-up organization, pneumatic systems, control modules and other main components. Designed the tank structure for a gas pressure storage, and selected the control module master chip LPC1114 and solenoid valve 3V330C-10 B by the actual needs of, designed the control module circuit schematics, PCB version and the debugger program.Using the CFD software Fluent completed the flow field uniformity analysis of two different structures of tank cavity, solved the flow field pressure contours, determined the optimal gas tank cavity structure by comparing the specific parameters; then by simulating flow field states of the hole into which the air jet at different velocity under subsonic speed, drew a conclusion by analytic statistics the initial and final pressure of the airflow: There is a approximately proportion relationship between the final pressure and the initial pressure. This Conclusion provides proof of the feasibility for zero-velocity seedlings vote theory again.Finally, designed the test system of pneumatic-picking seedling based on aperture disk vertical pick-up device, adopted the picking seedlings affecting factors to make a three factors and four levels orthogonal experiment, through the statistical analysis software SPSS integrated and analyzed the result of relevant test data, confirms the optimum operating parameters. That is the nozzle initial airflow pressure of 0.2MPa, plug inclination of 90 °, nozzle radius of 2.5mm, providing a reference for the structure improvement and parameters optimization of subsequent tomato automatic transplanting machine automatic picking seedlings system.