Fuzzy controller for the compensation of path deviations during robotic milling operations

Despite their high flexibility and - compared to traditional machine tools - low investment costs industrial robots are nowadays rarely used for machining operation like milling. The main reason for this is the huge deflection of the tool caused by the cutting forces and the low static stiffness of the robot structure. Hence, the application areas of milling robots are restricted to processes with low accuracy requirements or easy to machine materials like wood or foam plastics. This paper presents a method to increase the operational accuracy of milling with industrial robots by a model-based fuzzy controller. The approach was implemented on a robot of type KUKA KR 240 R2500 prime and validated by machining experiments.