含有闭环的并联贴标机构运动学分析

目的为了提高贴标机构的通用性,解决流水线上不同倾斜面上的贴标问题,提出一种含有闭环的并联贴标机构,并进行运动学分析,研究其自由度和工作空间,验证其作为贴签机构的可行性。方法建立并联机构三维模型,利用螺旋理论分析机构的自由度,使用闭环矢量法求出机构的运动学逆解方程。利用Matlab的计算功能,采用空间极限搜索法求解机构的工作空间,绘制机构的工作空间,并分析机构在不同点的最大旋转角度。结果该并联机构拥有2个移动,1个旋转自由度;工作空间紧凑无空洞,形状规则;垂直方向大部分工作空间最大转角可达90°。结论该并联机构结构简单,垂直方向转角大,动平台旋转中心易调;结合并联机构固有的刚度大、结构稳定、惯性小的优点,可以高效地完成流水线上不规则产品贴标工序的贴标任务。

Kinematic Analysis of Labeling Mechanism Based on Closed-loop Parallel Mechanism

The work aims to propose a labeling mechanism based on closed-loop parallel mechanism to carry out the kinematic analysis, study its degree of freedom and workspace and verify its effectiveness, so as to improve the universality of labeling mechanism and solve the labeling problems on surfaces with different inclinations in assembly line. The model of parallel mechanism was established, the freedom degree of the mechanism was analyzed by the screw theory, and then the inverse kinematics solution of the mechanism was obtained by the closed-loop vector method. The calculation function of Matlab and the three-dimensional coordinate search method were used to solve and draw the workspace of the mechanism and analyze the maximum rotation degree of the mechanism at different points. The parallel mechanism had 2 kinds of movements and 1 rotational freedom. The workspace was compact, void-free and regular in shape. The maximum rotation angle of most workspace in vertical direction could reach 90°. The parallel mechanism has simple structure, large rotation angle in vertical direction and easily adjusted rotating center of the moving platform. Combined with the inherent advantages of parallel mechanism, such as high stiffness, stable structure and small inertia, the labeling task of irregular products on the assembly line can be completed efficiently.