Kinematics and optimal design of a novel 3-DoF parallel manipulator for pick-and-place applications

In this paper, a novel 3-degree-of-freedom planar parallel manipulator, the V3 robot, is introduced. The manipulator consists of three RRR (R: revolute joint) subchains, which are respectively arranged in three-parallel planes. The three-actuated joints are designed to have a common rotation axis, which contributes the large workspace and unlimited rotational capability of the robot. The kinematics, including the loop-closure equations, the inverse kinematics, singularity, and workspace are briefly analysed. By directly considering the velocity and the accuracy indices for pick and place operations, the optimal design problem is formulated to maximise the good performance workspace, where lower bounds on the average extreme velocity and upper bounds on the average extreme error are applied as constraints. The optimal design shows greatly improved performance in workspace, velocity, and accuracy.