目的 针对自动包装生产线上快速、高精度的分拣，提出一种含有闭环单元的2-UPS/(S+SPR)R并联机构。方法 利用螺旋理论建立2-UPS/(S+SPR)R的旋转矩阵，得到机构的自由度。采用闭环矢量法计算出机构的位置逆解。在SolidWorks中，通过Motion分析得到工作空间的所有数据点坐标，然后将全部的数据点导入Matlab，绘制出机构有效的工作空间。结果 求解显示该并联机构有绕x轴转动、绕y轴转动和沿y方向移动等3个自由度，得到盾牌形弧状的工作空间。结论 该机构具有较大的运动空间，且灵活性好，能够有效地提高包装工作效率。

The work aims to propose a 2-UPS/(S+SPR)R parallel mechanism with closed-loop unit for fast and high precision sorting in automatic packaging production line. The rotation matrix of 2-UPS/(S+SPR)R was established with the screw theory to obtain the degrees of freedom of the mechanism. The inverse position solution of the mechanism was calculated by the closed-loop vector method. In SOLIDWORKS, all the data point coordinates of the working space were obtained through Motion analysis, and then all the data points were imported into Matlab to draw an effective working space of the mechanism. The solution showed that the proposed parallel mechanism had three degrees of freedom around the x-axis, around the y-axis, and in the y-direction, resulting in a shield-shaped arc-shaped working space. The proposed mechanism has a large movement space and good flexibility, which can effectively improve the working efficiency of packaging.