Automatic detection system for broken tools in CNC machining centers using advanced machine vision techniques

An apparatus with protective environmental enclosure for measurement and determination of key characteristics of machine cutting tools used in a CNC machining center with a machine vision measuring system comprising:

• a) an image processing computer for image acquisition, image storage and image processing capability;
• b) the image processing computer comprising memory for storing images formed by a camera;
• c) the image processing computer also comprising digital parallel input/output, digital serial, and ethernet communication capabilities for providing messages to external devices to report one or more measurements or characteristics of the machine cutting tool;
• d) the image processing computer executing control software stored in a computer readable medium, for allowing request and response signals from external devices indicating a machine cutting tool to be inspected, for causing the image processing computer to perform image alignment and analysis for extraction of key characteristics of the machine cutting tool, as well as for causing the image processing computer to store a reference image of a new and unused machine cutting tool in a memory location referenced by a specific identification code that is unique to a specific machine cutting tool model or type, as well as causing a determination of the exact position of the machine cutting tool by extracting one or more edges or edge points based on grayscale sub-pixel information;
• e) a camera having one or more image sensors and a lens for providing a spatial resolution and depth of field necessary to form a sharp focus image of a machine cutting tool or a target portion thereof including the cutting tool tip;
• f) wherein each image sensor comprises sufficient pixel resolution to resolve an imperfection in a profile of the machine cutting tool or the target portion thereof including the cutting tool tip;
• g) an LED backlight illumination system positioned on the opposite side of the machine cutting tool from the camera that forms a silhouette of the machine cutting tool;
• h) a front lighting illumination system positioned on the same side of the machine cutting tool as the camera that highlights surface characteristics of the machine cutting tool;
• i) a motorized translation stage for moving the camera and the LED backlight and front lighting illumination systems parallel to an axis of rotation of the machine cutting tool and maintaining an orientation of an optical axis perpendicular to the axis of rotation of the machine cutting tool;
• j) a protective enclosure containing the camera image sensors, the lens, both the LED backlight and the front lighting illumination system, and the motorized translation stage inside when positioned in a rest position;
• k) a moveable door on the protective enclosure with a pneumatic or electric cylinder to assist the opening and closing of the door;
• l) a rear door with a liquid tight seal located opposite the moveable door that provides access to the camera image sensors, the lens, both the LED backlight and the front lighting illumination system, and the motorized translation stage when in the rest position;
• m) an optical encoder for providing position information for ensuring that movement of the camera and the LED backlight and front lighting illumination systems reach a predetermined position where one or more images of the machine cutting tool are acquired;
• n) whereby sensors are positioned relative to the tool, whereby a focal point of detection coincides with the center of a cross-sectional diameter so to view a feature to be measured, whereby the tool is held in a consistent location for each inspection, and whereby said LED backlight illumination system and said front lighting illumination system provide a contrasting geometric size and shape of all of the features on the tool.