  In this paper a new asymmetric 3-translational (3T) parallel manipulator,
i.e., RPa(3R) 2R+RPa, with zero coupling degree and decoupled motion is firstly
proposed according to topology design theory of parallel mechanism (PM) based
on position and orientation characteristics (POC) equations. The main
topological characteristics such as POC, degree of freedom and coupling degree
are calculated. Then, the analytical formula for the direct and inverse
kinematic are directly derived since coupling degree of the PM is zero. The
study of singular configurations is simple because of the independence of the
kinematic chains.
