中文摘要：

为得到雅可比矩阵恒定的移动并联机构,基于螺旋理论利用机构的主运动螺旋和传递力螺旋求解机构的雅可比矩阵,给出了移动并联机构在不同位置下雅可比矩阵保持恒定的判定条件。在此基础上,基于约束螺旋理论对具有该特性的分别包含三自由度、四自由度和五自由度分支的这类三自由度移动并联机构进行构型综合,构造并得到了多种雅可比矩阵恒定的移动并联机构。分析3-PPRU和3-CPU两种并联移动机构,由得到的机构在工作空间内不同位置下的输出速度、力变化曲线图可以看出在给定确定的输入情况下,机构的同一输出参数曲线在不同位置时相互重合,从而验证了该类型移动并联机构雅可比矩阵始终保持恒定。

英文摘要：

To obtain the translational parallel mechanism with constant Jacobian matrix, a method solving Jacobian matrix of mechanism using main movement screw and transmission wrench screw is proposed based on screw theory. Some determination conditions in a translational parallel mechanism requires to keep its Jacobian matrix constant in different poses are presented. On this basis, a class of 3-DOF translational parallel mechanisms each limb of which has three, four and five joints with the above characteristic is synthesized based on screw theory. Many different translational parallel mechanisms with constant Jacobian matrix are obtained. By taking the 3-PPRU and 3-CPU translational parallel mechanism as examples, the Jacobian matrices of the mechanisms are analyzed. According to the former analysis, graphs of time-rate change of the output speed and force for the mechanisms in different poses are presented. It can be seen from the graphs that the curves of the same output parameters for the mechanisms will mutual coincide in different poses with the certain input parameters. Thus, the conclusion that Jacobian matrix of the class of translational parallel mechanisms keeps constant is verified.