(A) microcomputer based industrial eye for positioning and centering of holes

Abstract

An industrial eye is developed and applied for the purpose of positioning and centering of holes. The industrial eye consists of a vidicon camera as an image pick-up device, a control circuit, an interface circuit for interfacing the camera with an APPLE II microcomputer and a camera positioning mechanism. The control circuit is developed to control the digitization sequence for the digitized image data. The APPLE II microcomputer receives the image data, interpretes them and actuates the camera positioning mechanism. Algorithms for determining the hole center position in the image data are developed. One algorithm uses a method of averaging. The other algorithm determines the hole position by using templates although the background image is shown in the image frame after the camera is moved. These algorithms are programmed in machine language in order to be readily executed by the microcomputer. The experiments are performed where the calibration of the camera positioning mechanism is accomplished automatically so that the information on the distance between the camera and the object is not necessary. The results show that the positioning of the camera for bringing the image of the hole into the center of the image frame is performed within the error range of a few pixels.