A BEAM-LIKE DAMPER FOR ATTENUATING TRANSIENT VIBRATIONS OF LIGHT STRUCTURES

When a flexible robot arm, a cantilevered beam type of structure, moves with a fast speed between workstations and is suddenly stopped after a new positioning is completed, excessive transient vibrations are produced as a result of the flexibility. An impact damping technique may be used to control these excessive transient vibrations. Effect of the orientation of the robot arm relative to the gravitational acceleration is investigated for the conventional impact damper. A new impactor, in the form of another cantilevered beam, is suggested here as an impact damper the performance of which is independent of the orientation of the arm. Design charts, produced from numerical simulations, are presented to demonstrate the vibration attenuation capability of the conventional and the proposed impact damper. Experiments are described briefly to confirm the validity of the numerical model. © 1993 Academic Press Limited.