Optimal kinematic design of a new 3-DOF planar parallel manipulator for pick-and-place applications

This paper presents an optimal kinematic design of a new 3-DOF planar parallel manipulator for pick-and-place operations. After reviewing existing architectures of high-speed and high-acceleration parallel manipulators, a new design of 3-DOF parallel manipulator is presented with a co-axis actuated joints arrangement and three subchains in parallel planes. First, the loop-closure equations of the robot are derived. The inverse kinematics and singularity analysis are discussed. After that, the index of the average inverse condition number is used for design. For kinematics, velocities are important for pick-and-place applications. Bounded velocities indices are also used to limit the lengths of the links. Finally, the result of the optimal design has been analyzed. This optimal method can be applied to other manipulators for pick-and-place operations.