Rotational Axes Analysis of the 2-RPU/SPR 2R1T Parallel Mechanism

This paper presents a novel 2-RPU/SPR 2R1T parallel mechanism, which has one translational degree of freedom (DOF) and two rotational DOFs. The properties of the rotational axes of the mechanism are analyzed by using screw theory, and the results show that the 2-RPU/SPR mechanism has two rotational continuous axes. The position analysis of the 2-RPU/SPR mechanism is also carried out. The proposed 2R1T mechanism has very simple kinematic model, which reduces difficulties in calibrating kinematic parameters.