Modeling, Optimization And Test Of Planting Mechanism Transmitted By Eccentric-pascal Curve Non-circular Gears

Transplanting can compensate the climate and improve the comprehensive benefit to cropgrowth in early, and it can improve the cropping index. However, the development of automaticmechanical planting technology in China is low, so as the popularization rate of mechanicaltransplanting. From the actual experience at home and abroad, planting mechanization is thebasic way to lighten the labor intensity and also is the direction of the development in the future.Transplanting mechanism is ultimate mechanism that has seedling planted in the field, it is thecore mechanism of the transplanting machine, whose behavior directly affects the survival rate ofseedlings. The evaluation criteria of planting mechanism is high verticality rate of seedlings andlow damage rate in high speed. Aiming at these problems of existing planting mechanism, thisthesis puts forward a new type of planting mechanism, by ensuring the kinematic characteristicsof desired trajectory, gesture, velocity of planting nozzle and the shape of the opening to improvethe seedling rate and reduce the damage rate, and the modeling analysis and experimental studyon the new mechanism was carried on.The main research contents are as follows:1) Study on the degenerative Pascal curve non-circular gears and modified eccentriccircular gears. Based on the traditional pitch curve equation of Pascal curve non-circular gears,eccentric circular gears and its conjugate non-circular gears, carry study on the modifiednon-circular gears pitch line and center distance increasing degeneration. Use advance retreatmethod and golden section method to calculate the center distance. According to the formula ofcurve radius of each point, the concave-convex discriminant model of modified non-circulargears was established.2) Put forward the eccentric-Pascal non-circular planetary gear planting mechanism, andproposed its kinematic analysis mathematical model, using Matlab to write the kinematicsimulation and optimization software of the mechanism. Using the software the study howparameters such as eccentricity, curving circle radius, degeneration, initial angular displacementeffect the desired trajectory, gesture and the shape of the opening. Using the software to obtain the optimum parameters by the function of man-computer interaction, making a better gestureand opening size, to meet the agricultural requirement better.3) Established the model of the eccentric-Pascal non-circular planetary gear plantingmechanism, using Matlab to write the dynamic simulation and optimization software of themechanism.4) The3D model of the mechanism was established according to the optimum parameters,and then complete the structure design and virtual prototype simulation.5) Developed the eccentric-Pascal non-circular planetary gears planting mechanism andcarried on the experimental study. Using high-speed photography and video processingtechnology to verify the accuracy of the kinematics trajectory and attitude of the mechanism.atthesame time using vibration test instrument, to measure the support force point, and themeasured data and the kinetic theory model to compare, verify the accuracy of the kinetic model.6) In order to further verify the superiority of the dynamic characteristics, seven-rod typeplanting mechanism was selected as comparison objects, and its dynamic model was established,and the dynamic characteristics are compared between the two planting mechanism, whichproved he superiority of the proposed mechanism.