This paper proposes a 3-PPRU parallel mechanism (PM) with a completely/partially/non constant Jacobian matrix. Based on screw theory and selecting actuating components theory, the reasonability of the actuating input selection is analyzed. By different actuating selection, the Jacobian matrix of the PM can realize completely/partially/non constant. The direct, inverse and combined kinematic singularities of the PM with three different Jacobian matrices are discussed. The velocity, payload and stiffness performance of the PM are discussed and compared. A new index, as auxiliary evaluation index, is proposed first.

中文翻译：

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具有完全/部分/非恒定雅可比矩阵的3-PPRU并联机构的性能分析

本文提出了一种具有完全/部分/非恒定雅可比矩阵的3-PPRU并联机构（PM）。基于螺杆理论和执行机构选择理论，分析了执行机构输入选择的合理性。通过不同的执行选择，PM的雅可比矩阵可以完全/部分/非恒定地实现。讨论了具有三种不同雅可比矩阵的PM的正向，逆向和组合运动学奇点。对PM的速度，有效载荷和刚度性能进行了讨论和比较。首先提出一种新的指标作为辅助评价指标。