TOPOLOGICAL SYNTHESIS OF TRANSLATIONAL PARALLEL MANIPULATORS

For translational parallel manipulators (TPMs), topology synthesis methods that can be found in the literature are mainly based on screw theory, instantaneous kinematics, or group theory. In this work, finite displacement equations are used for the topology synthesis of TPM. Serial chains with less than 6 degrees of freedom (DOF) are first investigated and, topological conditions for them to generate 3D translations while its end-effector (EE) is under a constant orientation constraint are derived. Then the parallel manipulators (PM) composed of these serial chains are analyzed to find out whether and under what conditions the EE will keep a constant orientation throughout a finite workspace.