Balancing of Manipulators by Using the Copying Properties of Pantograph Mechanisms

Abstract

This Chapter is devoted to the balancing of robot manipulators and hand-operated manipulators by the use of copying properties of pantograph linkages.

The Sect. 6.1 develops a methodology for the balancing of the Delta robot, which is applied as an assisting device for carrying a microscope in surgical operations. It is shown that the use of an auxiliary balancing system consisting of a pantograph linkage can considerably reduce the load on the DELTA robot actuators.

In Sect. 6.2, a new four dof parallel manipulator with high-load carrying capacity is presented. This manipulator generates Schoenflies motions (i.e. three translational dof and one rotational dof around one fixed axis). The particularity of the proposed architecture, which has been patented (Arakelian et al., 2006) is the decoupling of the displacements of the platform in the horizontal plane from its translation along the vertical axis. Such a decoupling is attained thanks to the special design of the robot legs carried out by pantograph linkages. It allows the cancellation of the gravity loads on the actuators which displace the platform in the horizontal plane.

Finally, in Sect. 6.3, the design and balancing of hand-operated manipulators of the pantograph types are proposed. The balancing method is based upon a study concerning the com motion. New and more efficient kinematic schemes of hand-operated manipulators are suggested on the basis of this method.