目的 针对袋装食品的抓取和装箱过程操作简单且重复性高，采用人工完成的成本过高，极易发生少装和错装的现状，设计一种以2-RPS-UPU并联机构为主体的抓取和装箱机器人，验证其是否具有良好的运动学性能。方法 通过运用螺旋理论和修正的Grubler-Kutzbach公式对机构的自由度数目和类型进行分析，接着使用“闭环解析法”和“欧拉角表示法”2种方法推导该机构的运动学位置反解，采用粒子群优化算法对该机构进行位置正解算例分析。最后利用SolidWorks软件采用“驱动动静结合”的方法求解机构的工作空间。结果 该机器人具有3个自由度（两转一移），驱动关节和末端执行器之间的位置及姿态关系明确，可以进行良好的线性运动，工作空间呈蜘蛛网状，范围广且形状规则对称，结构紧凑。结论 该新型三自由度并联机器人能够满足袋装食品抓取和装箱时所需的运动和工作范围，其运动平稳，可靠性强。

The work aims to design a grasping and packaging robot with 2-RPS-UPU parallel mechanism as the main body and verify whether it has good kinematic performance, in view of the current situation that the grasping and packaging process of bagged food is simple and repetitive, the cost of manual operation is excessively high, and it is likely to cause less and wrong loading. The number and types of degrees of freedom of the mechanism were analyzed with the screw theory and the modified Grubler-Kutzbach formula. Then, the inverse position solution to the kinematics of the mechanism was derived based on "closed-loop analytical method" and "Euler angle representation method", while the forward position solution of the mechanism was analyzed by means of particle swarm optimization algorithm (PSO). Finally, Solidworks software was used to solve the workspace of the mechanism through the "combination of driving dynamics and statics". The proposed robot had three degrees of freedom (two rotations and one movement) and clear position and attitude relationship between the driving joint and the end actuator. It could perform good linear motions. The workspace was like a spider network, featured by a wide range, regular and symmetrical shape and compact structure. The new three-degree-of-freedom parallel robot can meet the motion and working range required by grasping and packaging of bagged food, and it has stable motion and strong reliability.