Sensor-based 3-D autonomous surface-following control

Many industrial operations can be automated using robot arms that, however, require the use of robots being able to perform surface-following in an adaptive way. Surface-following in real-time based on sensor information is a delicate task to overtake, yet very useful in operations like painting, welding, glues administration and surface polishing. The surface-following can be accomplished either by using previous knowledge of the shape of the surface, by executing a sequence of movements point-by-point, or in an adaptive way. In the last case a sensor or a set of sensors for collecting data from the environment is used. Furthermore, the surface-following can be characterized by occur with or without robot-surface contact. The paper describes a 3-D surface-following controller. The surface-following operation is performed in real-time, out of contact using proximity information. Experimental results concerning 3-D surface-following movements performed by a PUMA 560 robot are shown.