Vision-Based Object Recognition And Acquisition

Abstract

A vision guided robot work station is described, which is able to track and grasp objects moving on a conveyor belt. The vision algorithms are implemented on a ICOS 20000 Vision Computer. The Unimation Puma 560 robot running under VAL II offers the possibility of real-time path control. All movements are under guidance of the vision computer without any default path being programmed. Via a serial link, continuous updates for position and velocity are given, until the robot arm is correctly positioned above the object. A M68000 microprocessor based interface establishes the necessary protocols for robot - image computer communication. It also minimizes the length of the messages and takes time delays into account. The underlying vision algorithms are based on multi-resolution curvature measures for the object contours. These contours are first encoded with the "reduced generalized chain code". The vision system includes an automated modelling facility and preliminary algorithms for the generation of optimal recognition strategies. In order to accelerate recognition and localization, the concept of feature saliency was adopted.