空间3-UPU／UPU机构的刚度分析

以3-UPU／UPU并联机构为例，进行机构分析及运动学分析，得到机构的雅克比矩阵；在静平衡条件下计算出并联机构的局部刚度矩阵和全局刚度矩阵；利用数学软件MATLAB绘制3-UPU／UPU并联机构的局部刚度曲线以及全局刚度曲线，分析上下平面外接圆半径的变化对局部刚度和全局刚度的影响．结果表明局部刚度矩阵以及全局刚度取决于机构的位姿，对于给定的位姿可求机构局部刚度及全局刚度的变化范围；机构的上下表面半径的变化情况影响着局部刚度和全局刚度，因此可以适当地增大上下表面半径来获得较高的局部刚度以及全局刚度。

The stiffness analysis on space 3 -UPU / UPU organization

Taking the3 -UPU/UPU parallel mechanism as an example, the structure and kinematics a- nalysis were analyzed and the Jacobian matrix of the mechanism was obtained; the parallel mechanism of local stiffness matrix and the global stiffness matrix were calculated under static equilibrium condi- tion; the local stiffness curve and global stiffness curve of 3 - UPU/UPU parallel mechanism were ob- tained by the use of mathematical software MATLAB. The effect of variation of upper and lower plane circle radius on the local stiffness and global stiffness were analyzed. The results show that local stiff- ness matrix and the global stiffness depend on body posture. The variation range mechanism of local stiffness and global stiffness could be gotten for a given position ; the upper and lower surface radius var- iation of body affects on the local stiffness and the global stiffness. So that high rigidity of the local and global stiffness can be obtained by increasing appropriately the radius of the upper and lower surfaces.