Effect of Changing the Position of Tool Point on the Moving Platform on the Kinematics of a 3RRR Planar Parallel Manipulator

This paper discusses the effect of changing the location of the tool point, on the mobile platform, on the kinematics of a planar parallel manipulator. It is shown that changing the position of the end-effector greatly changes the shape and the area of the reachable workspace. Global conditioning index and the structural length index are used as global indices to find the optimum location of the end-effector on the mobile platform of a parallel manipulator. The results show that the performance criteria are varying in opposite directions, the dexterity is decreasing when the workspace area is increasing. Hence, the problem of optimal design becomes a problem of determination an acceptable compromise between the two requirements. The results of the present work show that the position of the end-effector on the mobile platform should be considered while optimizing the performance of a parallel manipulator.