Kinematic Analysis of 3-DOF Position Mechanisms for Use in Hybrid Kinematic Machines

This paper introduces a new kinematic architecture called the hybrid kinematic machine. A hybrid kinematic machine typically consists of a position mechanism and an orientation mechanism that can be arranged in series or in parallel to achieve the notion of modular and reconfigurable machining centers. To demonstrate the concept, four parallel manipulators with translational motion characteristics have been identified. The kinematics of these mechanisms are described. Then, the well-conditioned workspace of each mechanism is maximized, and the stiffness properties are mapped. A comparison of the workspace volume and stiffness properties of these four mechanisms indicates that the 3-RUU manipulator appears to be the best design among the four architectures.