Study On Vertically-grasping Rice Pot Seedling And Wide-narrow Distance Transplanting Mechanism

The technology of rice pot seedling and wide-narrow distance transplantation work by the transplanter grasping single pot seedling and planting with wide and narrow distancing.It has the advantages of both technology of pot seedling transplanting and wide-narrow distance transplanting,which less damaged to root in the process of grasping seedling,no recovery period,the capacity of resistance to lodging,disease prevention also can be enhanced by increasing ventilation and lighting,thus the quality and yield of rice can be improved.However,there's lacking of developed transplanter to replace artificial transplanting,which is inefficient and labor-intensive.It's hard to generalize this technology extensively,and no benefit to the rice yield and quality,restricting the development of rice planting mechanization in our country.The technology of pot seedling and wide-narrow distance transplanting is based on domestic rice planting requirements presented by agronomic experts,which the only solution to the application of this technology is independent innovation of transplanter.And,the key is to present a pot seedling transplanting mechanism working by wide-narrow row spacing.Meanwhile,it requires that not to change the moving-box mechanism,transmission parts and structure of seedling box with the purpose of matching with the bowl-growing tray and mature seedling pipeline.In this dissertation,the kinematic characteristics of the pot seedling and wide-narrow distance transplanting mechanism with spatial planetary gear train were studied by the way of theoretical analysis and experimental verification as well as the mechanism parameters optimization.Eventually a transplanting mechanism meeting all the requirements of optimization was designed.The main research contents and results are as follows:(1)The home and abroad transplanting mechanism that have planar trajectory and spatial trajectory working principles were studied and the characteristics of general single-freedom of two-stage planetary gear train mechanism were analyzed.A calculation method of nonuniform velocity of planetary gear train mechanism on the basis of the given trajectory was presented,and its kinematics model was established based on the theory of Denavit-Hartenberg transformation matrix.(2)The configuration of spatial planetary gear train were analyzed by the requirements of mechanism transmission.The noncircular gear and bevel gear planetary gear train was chosen to apply in vertically-grasping rice pot seedling and wide-narrow distance transplanting mechanism.A desired static trajectory of transplanting mechanism was obtained by analyzing the requirements of the technology.(3)The nine optimization goals of the transplanting mechanism based on the requirements of the motion trajectory and attitude of mechanism were given,and their functional relationship between optimization objectives and mechanism parameters were expressed.Optimization program was compiled by using Matlab software,and a set of parameters which meet all of transplanting requirements were obtained.(4)After the structure design of transplanting mechanism,the three-dimensional model was built.And virtual prototype test was performed to analyzing the attitude of picking arm as well as its static trajectory and velocity by Adams software,which verifying the rationality of structure design.(5)Physical prototype of pot seedling and wide-narrow distance transplanting mechanism was manufactured.Based on the currency test-bed,the trajectory and the parameter values of optimization goals were tested by using digital camera and Blaster's MAS software.All the inspected results agree with the requirements of technology,which verifying the calculation and optimization method of mechanism.