Ressorts et mecanismes: Une solution aux problemes d'equilibrage

Abstract

This paper deals with the problem of static balancing of robots. Indeed as a manipulator moves, it transmits forces to its surroundings, unless it is balanced these forces result in vibration, noise, wear and cause fatigue problems. Balancing may be accomplished through the addition of inertia counterweights and restrictions on arm configurations. Irreversible transmission such as screw nut type are also used. But the use of these techniques to achieve force and moment balancing induce significant effects on input torques, robot control and configuration. So to reduce loading characteristics, which can significantly enhance machine process, we present a new method to balance manipulators by springs. The potential energy storage capabilities of linear springs are integrated with non linear motion of manipulator to provide an exact value of the desired counter loading functions. This is performed by introducing simple mechanism between the spring and the structure to be balanced. Synthesis techniques based on torque balancing and energy method, are developed to design the characteristics of mechanism and spring capable of balancing a given structure. Examples are worked to demonstrate applications of these procedure and to illustrate industrial potential of spring balancing.