非圆齿轮系大蒜直立移栽机构优化设计与试验

Optimal Design and Experiment of Vertically Transplanting Mechanism with Non-circular Gears System for Garlic(Allium Sativum L.)

根据大蒜鳞芽直立朝上栽植的农艺需求,设计了一种可实现复杂栽植轨迹的二阶非圆齿轮行星轮系移栽机构。采用D-H方法建立了移栽机构的数学模型,通过对大蒜移栽轨迹与姿态进行分析,确定了直立移栽机构所需实现的优化目标;在Matlab平台下编写了移栽机构的GUI优化设计软件,利用参数导引启发式优化算法对机构进行了多目标参数优化设计,通过人机交互优选出一组非劣解;采用自上而下的参数驱动设计方法,在CATIA中完成了移栽机构的参数化建模,并对机构进行了虚拟样机验证;通过台架试验,获得各试验因素对大蒜移栽后倾斜角的影响规律;提出了针对不同工况的优化模型,在最佳参数组合方案下进行了验证。结果表明,当移栽深度为17 mm、机构转速为29.6 r/min、匹配速比为100%时,获得的蒜瓣倾斜角平均值为8.54°,当提高机构转速时,通过对参数方案进行优选可将倾斜角控制在合理的范围内,以满足大蒜直立栽植的农艺要求。

The agronomic planting technique of garlic with its bulbil facing upward accords with the growth characteristics and it can achieve a significant effect of increasing yield.The garlic planting machinery on the market is generally difficult to meet the agronomic needs of vertically planting.Based on the achievements in transplanting machinery and using a non-circular gear rotary transplanting mechanism as the core-working component,a vertically transplanting mechanism for garlic based on agronomic requirements was developed.Firstly,the mathematical model of the transplanting mechanism was established by the D-H transformation method,which was commonly used in robotics.With the analysis of the trajectory and posture of artificially planting garlic,a total number of twelve optimization goals required by the transplanting mechanism were determined.Since the optimization goals had characteristics of fuzzy,non-linear and strong coupling,the parameter-guided heuristic optimization method was used in the optimization process,and the GUI human-computer interaction optimization software was written under the Matlab software platform.After optimization,a set of design parameters meeting the requirements of the goals were calculated.Referring to the obtained optimizing design data,the contour shape of the non-circular gears were generated in KissSoft software.The top-down design method was used to parametrically design the transplanting mechanism by CATIA software,and simulation verification of the transplanting mechanism was carried out by using ADAMS software.Finally,an experimental bench for the garlic vertically transplanting mechanism was designed,and the multi-factor combination experiment was carried out with the transplanting depth,the rotation speed of the mechanism,and the matching speed ratio as the experimental factors.The quadratic regression orthogonal rotation combination design method was used to arrange the experiment,and the regression equation of the influence of each experiment factor on the bulbil angle of garlic after planting was obtained.The results showed that when the transplanting depth was 17 mm,the transplanting speed was 29.6 r/min,and the matching speed ratio was 100%,the average vertical angle of garlic bulbil would be 8.54°.When the transplanting speed was increased,the verification result was also in the desired range of agronomic requirements.The research results can provide a reference for the development of new garlic planting machinery and other transplanting mechanisms with complicated trajectory.