Identification et commande pour l'atténuation des vibrations du robot parallèle par2

摘要

The parallel robot Par2, conceived for high-speed and high-accuracy industrial pick-and-place operations, is subject to severe vibrations at the end of a trajectory. In order to minimize these vibrations, the use of piezoelectric patches wrapped around the robot arms is proposed. The open loop identification of the flexible modes of the robot, charged with 2,5kg and at the stop position, is performed by means of a subspace-based technique. Two models are identified, one for the controller synthesis and another one for validation in simulation. Some stabilizing controllers are obtained and compared for two control strategies: mixed H8 sensitivity and H8 Loop Shaping. The robustness of the controllers is tested for different trajectory and charge conditions. An anti-windup strategy is employed to correct the action of a controller when it shows no robustness to some limit situations. Some simulation and experimental results allow comparing the effectiveness of the controllers.