An inexpensive robot arm for computer vision applications

The authors have developed a simple, economical robotic arm with both image acquisition and range sensing capabilities for machine vision applications. It is connected via an interface board to an IBM PC/AT microcomputer, offering maximum flexibility in programming the arm for different tasks. A sonar ranging device and a video camera are mounted on the arm, and give the system 3-D vision capabilities. The sonar ranging device and associated clock/counter circuitry is connected to the computer via the same board as the robotic arm, whereas the video camera is connected to an image digitization and display board. To illustrate its capabilities, the arm was programmed to scan the immediate environment and attempt to locate and identify the nearest object. Standard image processing and computer vision techniques such as binary thresholding, histogram analysis, signatures and pattern recognition were applied, and excellent object recognition was achieved under a wide variety of lighting and distance conditions