Contribution à la mise en oeuvre et l'optimisation d'une cellule robotisée : application au parachèvement de pièces de fonderie

Abstract

The finishing of high-tech cast parts is an essential task which is carried out mainly manually. Given the extreme physical demands made on operators, the automation of this task is desirable. The present study relates to the industrial implementation of a robotized finishing cell. The first part presents the constraints related to the sand casting process and their impacts on finishing. The robotized process includes phases of machining and polishing with adjustment by vision system. The state of the art with respect to our integration constraints leads to the choice of a parallel substructure (Tricept) robot, with two additional axes introducing kinematic redundancies. Its implementation with respect to the process is carried out in three steps: analytical cell modelling obtained by serial equivalent; formalization of the process constraints; and resolution by multi-criteria optimization. This requires the definition of specific optimization criteria (precision, kinematics, stiffness) and enables cell behaviour to be improved by using kinematic redundancies. The final section presents real industrial conditions for the production of a validation part and the tool developed for optimization.