4-SPS/PPU型并联机构工作空间与尺度分析

Workspace and Scale Analysis of 4-SPS /PPU Parallel Mechanism

以4-SPS并联机构为研究对象,采用加约束从动支链的构型演变方法得到一类2T2R(两个移动和两个转动)4自由度并联机构。根据速度Jacobian矩阵分析了机构的奇异位形,建立了4-SP xyz S/P x P z U xz并联机构的工作空间求解的约束条件,得到了机构的位置和姿态工作空间,并提出利用'点集'近似计算位置工作空间大小的方法。引入敏感度概念,利用数值法解得了位置工作空间大小和姿态工作空间范围与机构尺度参数之间的关系,为机构尺度参数的选取提供了依据。

The parallel mechanism of 4- SPS was studied. 2T2R （2 translational and 2 rotational） 4-DOFs （ degrees of freedom） parallel mechanism were obtained by configuration evolution of adding and altering the follower-limb. The constraint condition of solving the position and attitude workspaee about 4 - SPxyS/PxPYxz parallel mechanism was built. The set of points was used to calculate dimensional size of workspace. The concept of sensitivity was introduced. The numerical method was used to calculate dimensional size of position workspace and scope of attitude workspaee in the solution of different scale.