Machanism Analysis And Optimal Design Of Walking And Straight-clipping Type Rice Pot Seedling And Wide-narrow Distance Transplanting Mechanism

The rice pot seedling transplanting is a new type of rice transplanting methods.Different from blanket-like seedling transplanting,the rice pot seedling transplanting is the process of cultivating seedlings in tray and then transplanting the seedling with soil bowl to the paddy field.The blanket-like seedling transplanting is the traditional way of rice planting,which tears the seedlings and then transplants them to the soil.This process may damage the roots of seedlings and make seedlings experience remission period after transplanting.While the pot seedling transplanting can maintain the integrity of the seedling root as the existence of nutritious soil bowl,so as to shorten the growth period of seedlings.Rice wide-narrow distance planting is a high photosynthetic efficiency agronomic planting method.Different from the traditional equal distance planting,wide-narrow distance planting is a way of planting rice seedlings with alternate wide and narrow rows.This method won't change the number of plants per unit area,in order to make full use of light,improve the ventilation in the field,reduce the amount of pests and use of pesticides.The walking and straight-clipping type rice pot seedling and wide-narrow distance transplanting mechanism proposed in this paper can complete the rice pot seedling transplanting and wide-narrow distance transplanting at the same time.This mechanism could combine the advantages of two new types of agronomic methods,and realize the mechanization of rice pot seedling and wide-narrow distance transplanting.In addition,it can reduce labor intensity,improve production efficiency,and realize the increase of rice yield.The existing rice pot seedling and wide-narrow distance transplanting mechanism could not be applied to actual production operation as it's lateral offset of trajectory is excessive when it pick up seedlings.While the proposed walking and straight-clipping type rice pot seedling and wide-narrow distance transplanting mechanism could get straight-clipping trajectory through the innovative design of the core components.The main research contents are as follows:1)Through the analysis of variable transmission characteristics and spatial transmission characteristics of various compound gear trains,the paper made innovate design on the core components of transplanting mechanism,and ultimately determine the scheme of crossed helical gears-noncircular bevel gears planetary gear train system.2)Non-uniform B-spline curve was used to fit the spherical pitch curve of non-circular bevel gear,and to calculated the tooth profile of non-circular bevel gear based on the pitch curve.The mathematical model of transplanting mechanism with planetary gear train was established according to the scheme of core components,which was based on D-H matrix transformation theory.The tip point of transplanting arm could achieve straight-clipping type "8 shape" space transplanting trajectory.3)The kinematic objects of trajectory and attitude of the walking and straight-clipping type rice pot seedling and wide-narrow distance transplanting mechanism was proposed in this paper.Then the parameters optimization system of the transplanting mechanism was established based on the Matlab software platform.The crossed helical gears-noncircular bevel gears planetary gear train transplanting mechanism aided optimization software was wrote according to the mathematical model,and ultimately a set of mechanism parameters meet the requirements was obtained.4)The structure design of transmission box,planetary gears box and transplanting arm component parts were completed according to the optimal parameters and transmission requirements of transplanting mechanism.The virtual manufacturing of transplanting mechanism3 D model was also completed in UG software.5)The 3D model of transplanting mechanism was imported into Adams software through intermediate format file,and the motion simulation of virtual prototype was completed.The simulation trajectory and velocity curve of transplanting mechanism was compared with theoretical design results,which verified the correctness of scheme,3D model and theory model of the walking and straight-clipping type rice pot seedling and wide-narrow distance transplanting mechanism.