Comparative study of two 2-RPU+SPR parallel manipulators

A comparative study of two over-constrained 2-RPU+SPR parallel manipulators (PM) is studied in terms of workspace and transmission performance in this paper. The two 2-RPU+SPR PMs have identical kinematics limbs, but some differences exist in terms of the joints distribution. The kinematics, the workspace and the transmission performance are studied and simulation examples are presented to demonstrate the differences between the two PMs. This study provides insights into the two parallel manipulators with identical limbs but with different joints distribution.