The Research Of Variable And Differencial Transplanting Mechanism For Zigzag Wide-narrow Row Rice Pot Seedlings

The rice pot seedlings and zigzag wide-narrow row transplanting is a new type of agronomic method,which can effectively improve the yield and quality of rice by combining rice pot seedlings transplanting and zigzag wide-narrow row transplanting.The rice pot seedlings transplanting is the process of picking seedlings with soil bowl from tray and transplanting into the field,which could overcome the drawback that blanket seedlings transplanting hurts rice root.The rice pot seedlings have strong disease resistance,high survival rate,no slow seedling,which will lead to a substantial increase in rice yield.The zigzag wide-narrow row rice seedlings transplanting is a method of planting adjacent rows of rice seedling alternately,and distributing wide and narrow rows.It could increase the lighting and ventilation of the field,thus reducing the plant diseases and insect pests,increasing lodging resistance ability of rice,and improving the rice yield and quality.As the traditional rice transplanter or rice pot seedling transplanter are unable to complete the zigzag wide-narrow row transplanting of rice seedling,it mainly relies on artificial to complete in the process of production.Due to the high operation cost and low efficiency,it is difficult to promote this agronomic method.In this paper,a variable and differential transplanting mechanism for zigzag wide-narrow row rice pot seedlings has been proposed.Based on the nonuniform and spatial transmission of differential gear train and the structure of bilateral transplanting arm,this mechanism could complete rice pot seedlings and zigzag wide-narrow row transplanting through space trajectory.The main research contents of this paper are as follows:1)Mechanism Innovation.Through exploring the mechanism configuration which can complete the rice pot seedlings transplanting and the zigzag wide-narrow row transplanting,a variable and differential transplanting mechanism has been put forward.In addition,the core part of this mechanism is the differential gear train,which consists of circular gears,non-circular gears and crossed helical gears.2)Theoretical research.Non-uniform B-spline curve was applied to fit the pitch curve of non-circular gear,and the transmission characteristics of noncircular gears were analyzed.Moreover,the mathematical model of gear train in gear case was established based on coordinate transformation theory.3)Parameter optimization.The trajectory and pose requirements of rice pot seedlings and zigzag wide-narrow row transplanting were parameterized into nine specific kinematics optimization objectives.The visual parameter optimization interaction interface based on mechanism mathematical model was compiled by MATLAB software.The effects of the structure and position parameters of the mechanism gear and transplanting arm on the target parameters such as shape,posture and track offset of the transplanting trajectory were analyzed.Ultimately,a group of structural parameters meet the requirements of rice pot seedlings and zigzag wide-narrow row transplanting was obtained.4)Three dimensional modeling and simulation analysis.The structure design of mechanical parts in the transmission case,gear case and transplanting arm are completed.Then the three dimensional model of mechanism were competed in UG software.The virtual prototype was imported into ADAMS software for kinematics simulation and analysis.Finally,the simulation trajectory and velocity data of the transplanting arm clip were basically consistent with the theory.5)Physical prototype test.The parts of the right transplanting mechanism were processed and assembled.The trajectory and attitude of transplanting arm were analyzed by self-made test bench,industrial camera and image processing software.The results were consistent with the theoretical data,which verified the feasibility of the transplanting mechanism scheme and the rationality of the structure.