Position Analysis for a Class of Novel 3-DOF Translational Parallel Robot Mechanisms

A class of new 3-DOF parallel robot mechanisms is investigated. Closed-formed solutions are developed for both the forward and inverse kinematics. Compared with available 3-DOF parallel robot mechanisms, these mechanisms are not only simple in structure with fewer solutions for position analyses but also decoupled. The mechanism decouplity is related to the topological characteristics, dimensional parameters, kinematic joint types and the choice of input-joints. Usually multi-limb mechanisms cannot be decoupled when their limbs are arranged symmetrically. Mechanisms analyzed in this paper overcome such a defect since their limbs are arranged specially. Moreover, it is found that P-joints included in the C-joints can improve the kinematics decouplity when they are input-joints. The mechanism decouplity is very useful for real control and path planning of parallel robots.