基于2-UPR/RPS并联机构尺度对工作空间的影响

针对目前并联机构工作空间较小、在生产实际中适应性较差的问题,对2-UPR/RPS机构进行运动分析和工作空间分析.首先,通过螺旋理论求解机构自由度,再利用修正后的Kutzbach-Grübler公式验证2-UPR/RPS并联机构的空间自由度,使用闭环矢量法求解该机构三条支链的运动学逆解,通过改变动静平台大小比例和运动副布置方式,观察对并联机构工作空间的影响.最后,在数学建模软件中对2-UPR/RPS并联机构可达工作空间进行仿真分析.该并联机构在空间中具有两转一移三个自由度,工作空间形状规则,无空洞,无突变.在生产实际中可根据实际情况选择合适的运动副布置方式及机构尺寸,可使该机构在满足实际需求的情况下在具有较大的工作空间.

Analysis of the Influence of the Dimensions of the 2-UPR/RPS Parallel Mechanism on the Workspace

In view of the small working space of parallel mechanism and poor adaptability in actual production, this paper conducts motion analysis and working space analysis on the 2-UPR/RPS mechanism. Firstly, the degree of freedom was solved by screw theory. The space degree of freedom of the 2-UPR/RPS parallel mechanism was verified by G-K formula, and the kinematic inverse solutions of the mechanism were solved by using closed-loop vector method. By changed the size ratio of the dynamic and static platforms and the arrangement of the motion pairs, the influence on the working space of the parallel mechanism was observed. Finally, the 2-UPR / RPS parallel mechanism reachable workspace was made in modeling software. The parallel mechanism has three degrees of freedom including two rotations and one movement in space. In production, the appropriate arrangement and the size of the mechanism can be selected according to the actual situation, so that the mechanism can have a larger working space while meeting the actual needs.