Experiments in robotic fettling using visual feedback

Increasingly, the laborious task of removing burrs on castings is being automated with the introduction of robots. This is largely to ensure higher level of consistency and efficiency generally not possible with manual fettling. These burrs are unpredictable in size and shape, and if not removed, can lead to major problems in automated factory lines. Fettling is an important area in advanced robotic applications. This paper presents a strategy using a compliant wrist unit to obtain forces during robotic fettling. A specialised fettling wrist unit incorporating a remote centre of compliance (RCC) unit and a CCD camera is described. Experiments are carried out to evaluate the feasibility of this method. Fettling experiments are also performed using a force/torque sensing unit. A comparison of the results of these experiments is provided. The process parameters for fettling are described and relationships among these are established.