基于图论的多杆式栽植机构构型综合与方法研究

针对目前栽植机械中多杆式栽植机构构型有限的问题，借助图论型综合的方式，构建完备的多连杆栽植机构构型库。首先，在连杆机构运动链综合中，基于加权四次幂矩阵与加权最小距离矩阵的方法，获取拓扑图顶点相似特征码，根据不同顶点间特征码的唯一性，开展运动链拓扑图相似点识别与同构判别；其次，建立栽植机构构型筛选规则，利用相似点的特征实现功能点的选取，建立了6构件至9构件机构功能拓扑图图库，得到六杆一自由度构型14个，七杆二自由度构型17个，八杆一自由度构型510个，九杆二自由度构型917个；最后，在构型库中选取不同构件数下的构型进行运动学建模，优化获得适合栽植作业运动要求的新型六杆、七杆、八杆栽植机构尺寸，并进行运动仿真验证了构型综合方法的正确性，可为多样化种植机械的创新设计提供更多可选构型。

Structural Synthesis and Innovative Design of Multi-link Planting Mechanism Based on Graph Theory

In view of the limited configuration of multi-link planting mechanism at present, a complete multi-link planting mechanism library was constructed by means of graph theory. Firstly, based on the method of weighted fourth power matrix and weighted minimum distance matrix, the similarity feature code of vertices was obtained in the kinematic chain synthesis of linkage mechanism. In accordant with the uniqueness of the feature code, the similarity recognition and isomorphism identification of the kinematic chain were conducted. Secondly, the specific screen rule of the planting mechanism configuration was established based on similarity of vertices, and then the functional vertices for input link, output link and rack were determined. The mechanism topology library of six-link to nine-link was established: the number of 6-link 1-DOF KCs was 14, the number of 7-link 2-DOF KCs was 17, the number of 8-link 1-DOF KCs was 510, and the number of 9-link 2-DOF KCs was 917. Finally, the configuration of different links consisted of six-link to eight-link in the planting mechanism library was selected for kinematics modeling, and the new size of six, seven and eight-link planting mechanisms suitable for planting operation were obtained. The correctness of the configuration synthesis method was verified by comparing the theoretical results with the motion simulation results, which provided more optional configurations for the innovative design of diversified planting mechanism. The use of structural synthesis method is conducive to the innovative design of planting mechanism.