Analysis of the 2PRU-1PRS 3DOF parallel manipulator: kinematics, singularities and dynamics

摘要

Parallel manipulators, especially those with outputs as a translation and two rotations (1T2R), are being increasingly studied. The 3PRS mechanism is a very typical example of this category, but it has peculiar kinematic characteristics caused by parasitic motions and by low orientation capability. To overcome these problems, new mechanisms are being studied, such as the 2PRU-1PRS manipulator. As in the case of the 3PRS manipulator, the degrees of freedom of the 2PRU-1PRS are one translation along the Z-axis and two rotations about the X- and Y-axes. The advantages are that the parasitic motion appears only in one direction instead of in three and that the orientation capability is higher.In this paper we solve the kinematics, singularities and dynamics of a 2PRU-1PRS mechanism. We first analyse a general 2PRU-1PRS mechanism and then present the results for the particular case of the 2PRU-1PRS used for automobile pieces testing purposes.