Optimization Of Non-circular Near Rotary Transplanting Mechanism Based On The Trajectory Of Seedling Needle

Rotary type transplanting mechanism is the core component of high-speed rice transplanter,whose motion trajectory of seedling needles mainly depends on the structure parameters ofnon-circular gear planetary trains. Recently, the solution method of rotary type transplantingmechanism is firstly given non-circular gear pitch curve function, then determine its structuralparameters. According to the less flexibility problem of design method, this paper studies themethod of designing non-circular gear transplanting mechanism based on static trajectory ofseedling needle. The method studied by the paper breaks through the design method that only thefunction of non-circular gear pitch curve is given can the solving process continues whendesigning transplanting mechanism. This paper has established the relationship between statictrajectory of seedling needle with gear ratio of non-circular planetary trains, developedoptimization software of transplanting mechanism design, proposed a new design method oftransplanting mechanism, completed transplanting mechanism design, prototype production andfield test. The main research contents and conclusions are as follows:1) Studied the technology development of rice mechanical transplanting and the presenttechnology situation and development trend of rotary type transplanting mechanism of ricetransplanter, analyzed the working principle and structural characteristics of non-circular geartransplanting mechanism, established the kinematics model of non-circular gears planetary traintransplanting mechanism whose seedling needle trajectory is expressed by numerical point.2) According to the structural features and working principle of rotary type transplantingmechanism, this paper studied the relationship between total gear ratio of non-circular gearplanetary trains and static trajectory of seedling needle, proposed the Fourier functionhypothesis of segmented transmission ratio of non-circular gear planetary trains, solved theproblem of solving segmented transmission ratio that the effective equation is not enough.Through iterative and fitting, segmented transmission ratio of non-circular gear planetary trainswas obtained. Non-circular gear of transplanting mechanism was designed, and a design methodof reversing non-circular gear of transplanting mechanism based on static trajectory of seedlingneedle.3) A interactive aided analysis optimization software was developed which was used to optimize the initial installation angle of the planet carrier and the planting arm and otherparameters. The difficult problem of multi-objective optimization of rotary transplantingmechanism was solved.On the basis of reverse design and optimization, the paper completed the transplantingmechanism design and manufacture, and analyzed the motion simulation of the mechanism.Theoretical analysis and field test proved that the research and development of transplantingmechanism can satisfy the requirements of mechanical transplanting, at the same time, alsoverified the correctness of designing non-circular gear transplanting mechanism based on statictrajectory of seedling needle.