Machining with industrial robots: The COMET project approach

Machining using industrial robots is currently limited to applications with low geometrical accuracies and soft materials due to weaknesses of the robot structure, insufficient controller performance and the lack of suitable software tools. This paper proposes a modular approach to overcome these obstacles, applied both during program generation (offline) and execution (online). Offline predictive machining errors compensation is achieved by means of an innovative programming system, based on kinematic and dynamic robot models. Realtime adaptive machining error compensation is also provided by sensing the real robot positions with an innovative tracking system and corrective feedback to both the robot and an additional high dynamic compensation mechanism on piezo-actuator basis. Due to the modularity of the approach, an individual setup can be compiled for each actual use-case. Final experimental validation of the components is currently ongoing in multiple robot cells, covering several application areas as aerospace, automotive or mould construction. The research work reported here was supported by the European Commission under the Seventh Framework Programme (FP7/2007-2013) within the project COMET under grant agreement #258769.