Kinematic design of a translational parallel mechanism based on sub-kinematic chain determined workspace superposition

This paper presents the kinematic design of a translational parallel mechanism (PM) named Vari-Orthoglide by means workspace superposition, according to sub-kinematic chain (SKC) based PM composition principle. The main topological characteristics manipulator with two SKCs under study, such as position and orientation (POC) characteristics, degree freedom (DOF) coupling are analyzed, which turns out that equals 1, implying partially decoupled motion. With modeling principle, symbolic model kinematics is established derive its direct inverse solutions. Based upon solution, workspaces for can be efficiently found. Moreover, singularity loci identified finding singularity-free workspace, where regular fitted task expected. presented work shows an approach mechanisms considering motion decoupling applicable other types mechanisms.