含冗余驱动支链4-UPS&UP并联机构的运动学性能分析

Kinematic Performance Analysis of Redundantly Actuated 4-UPS&UP Parallel Manipulator

分析含冗余驱动支链4-UPS&UP并联机构的运动学性能,该并联机构由著名的Tricept机器人并联模块3-UPS&UP机构增加一条无约束驱动支链所得。因冗余驱动支链的引入,该并联机构比3-UPS&UP机构拥有更高的承载能力和更好的静、动态性能。在建立4-UPS&UP机构的位置逆解模型和7×6广义雅可比矩阵的基础上,得到驱动关节速度到动平台参考点线速度的4×3量纲一雅可比矩阵,并据该矩阵的条件数提出局部运动学性能评价指标。最后,在同尺度下对4-UPS&UP和3-UPS&UP并联机构的运动学性能进行了对比分析,得到前者运动学性能优于后者的结论。

The kinematic performance analysis of a redundantly actuated 4-UPS＆UP parallel manipulator is dealt, which is a modified version of the 3-UPS＆UP parallel mechanism within the Trieept robot by adding a 6-DOF active limb. Compared to the 3-UPS＆UP mechanism, the proposed mechanism has higher payload capability and higher static/dynamic performance thanks to the additional active limb. On the basis of the inverse kinematics and the derivation of the 7x6 generalized Jacobian of the 4-U12S＆UP mechanism, the 4x3 dimensionless Jacobian can be obtained, which is the mapping between the rates of the actuated joints and the linear velocity of the reference point on the platform, and its condition number is then proposed as the local kinematic performance index. By carrying out the comparison study between the 4-UPS＆UP and the 3-UPS＆UP mechanisms given the same set of dimensional parameters, it is concluded that the kinematic performance of the 4-UPS＆UP mechanism is higher than that of the 3-UPS＆UP mechanism.