Adaptive Feed Control for Machining with Industrial Robots

The sector of machining hard materials like aluminium, steel or nickel-base alloys is dominated by conventional machine tools because they provide high reliability in production time and process accuracy. However, processing soft materials or products with low quality requirements are getting more interesting for standard industrial robots because of their low investment risks and short delivery periods. On the other hand, disadvantages like low absolute accuracy and low structural stiffness limit the area of industrial applications. Current research activities are focusing on compensation algorithms to reduce the static offset induced by process forces. Thus, this paper presents an approach of a control system which adapts automatically the feed rate depending on the cutting scenario. Linked with a Computer-Aided-Manufacturing system, predefined machining data is analyzed and stored on a separate Edge-Device. This Edge-Device communicates with the machining spindle and monitors the spindle power to monitor the cutting scenario. On this basis, deviations of the milling tool in the areas of entering and leaving the material could be reduced.