Milling with industrial robots: Strategies to reduce and compensate process force induced accuracy influences

Industrial robots offer a good basis for machining from a conceptual point of view. However they are rarely utilized for machining applications in industry due to their low stiffness and the bad achievable work piece quality. Available solutions using position control of the tool require costly additional hardware and measurement equipment; force controlled solutions depend on low level controller access that is not commonly available for generic cell setups. This paper proposes a three-step approach to compensate for process force induced accuracy errors: (1) selection of appropriate milling strategies and cutting parameters, (2) an offline compensation of the force induced deviations and (3) a respective online compensation method. Experimental validation of the results has been performed for the first two steps.