取秧侧向零偏移的空间轨迹再生稻分插机构设计与试验

Design and Experiment of Regenerated Rice on Space Trajectory Transplantation Mechanism with Zero Lateral Offset

为了解决现有空间行星轮系式分插机构在再生稻宽窄行机械化种植取秧过程中出现侧向偏移量和侧向偏转角的技术难题,本文提出一种具有局部平面轨迹特性的空间轨迹不等速行星轮系机构,并开展基于取秧口和机构回转中心位置约束下的宽窄行分插机构综合研究。构建了基于关键位姿点(取秧起始点、取秧结束点、推秧点)的空间轮系机构运动综合模型,利用关键位姿点求解机构杆长参数与空间交错轴信息,并通过优选二杆相对角位移参数实现机构传动比分配。将不完全非圆齿轮副引入空间行星轮系机构,利用间歇机构锁止弧约束行星轴,实现机构取秧过程侧向零偏移量、侧向零偏转角的平面轨迹段。通过仿真分析与机构样机试验验证了机构实际作业性能与理论设计相一致,结果表明:分插机构取秧侧向零偏移量,取秧侧向零偏转角,推秧侧向总偏移量为50.24 mm、取秧角为5.18°、推秧角为71.56°、推秧侧向角为16.26°、插秧穴口宽度为22.43 mm、轨迹高度为289.76 mm,满足预期设计要求。最后通过田间试验验证,分插机构可实现等行距取秧口和既定机构回转中心下宽行(40 cm)与窄行(20 cm)间隔机插,满足再生稻宽窄行种植要求。

In order to solve the technical difficulties of lateral displacement and lateral deflection angle in the process of mechanically seedling picking process in wide and narrow rows of regenerated rice using existing space planetary gear transplanting mechanisms,a spatial trajectory unequal velocity planetary gear train mechanism was proposed with local planar trajectory characteristics,and a comprehensive research on the wide and narrow row transplanting mechanism was carried out based on the constraints of the position of rice gate and mechanism’s rotation center.A spatial gear train mechanism motion model based on key pose points(take seedling starting point,take seedling end point,push seedling point)was constructed,and the mechanism rod length parameters and spatial interleaved axis parameters was solved by using key pose points.The transmission ratio distribution of the mechanism was realized by optimizing the relative angular displacement parameters of the two rods.The incomplete non-circular gear pair was introduced into the space planetary gear system mechanism,and the intermittent mechanism was used to restrain the planetary axis to realize the plane trajectory segment with zero lateral offset and zero lateral angle during process of taking seedlings.Through simulation analysis and prototype test of the mechanism,the actual operation performance of the mechanism was consistent with the theoretical design,and the operation performance parameters of the mechanism were verified as follows:the transplanting mechanism had zero lateral offset during the process of picking seedlings,and zero lateral offset angle during the process of picking seedlings,the total lateral offset of pushing seedlings was 50.24 mm,the picking angle was 5.18°,the pushing angle was 71.56°,the lateral angle of pushing seedlings was 16.26°,the width of the transplanting hole was 22.43 mm,and the trajectory height was 289.76 mm,which met the expected design requirements.Finally,the field experiment verified that the rice transplanting mechanism could achieve wide row(40 cm)and narrow row(20 cm)spacing plant under the equal distance taking position and the established rotation center of the mechanism,which met the requirements of wide row and narrow row planting.