Flexible Accuracy for Doors

Article From: 7/1/2005 Automotive Design & Production, , Editor-in-Chief from Gardner Business Media, Inc.

Ring gauges are pretty much the industry standard for checking doors.

Ring gauges are pretty much the industry standard for checking doors. And proper door fit is still one of the things that consumers consider when making a purchase decision, so the right door dimensions are critical. While ring gauges can get the job done, there are some issues, such as their inherent inflexibility (they are hard gauges), their expense (in time to develop and money to make), their size (when more than one door style is produced, this means more gauges; more gauges means more storage space), and the fact that there can be human error involved in the process. So Perceptron (www.perceptron.com; Plymouth, MI) has developed what they're calling a "flexible ring gauge," based on the work that the company has done for its AutoScan 3D non-contact, laser-based system. The elements are essentially a structured light sensor (i.e., laser), a CCD camera, robot, and hardware and software system that manipulates and assesses the collected data. What happens in process is that an operator puts the hemmed door in a fixture, hits a button, then gets a green or red light: good or bad. The system automatically analyzes the measured data in relation to the actual CAD model to make the determination (preset limits dependent on process capability can be input). Information is then written to a file. Fast, accurate, efficient. And, according to Mark S. Hoefing, Perceptron's executive director of Sales & Marketing, economical. That is, while the initial cost of a full-blown flexible ring gauge may be on the order of $500,000 and a single hard-tooled gauge $120,000, the difference is not only in the need for multiple conventional ring gauges for a single vehicle (consider a four-door), but the fact that it can take six months to obtain a hard-tooled gauge and three months for a flex system, to say nothing of the fact that reconfiguration costs are a fraction of buying new gauges for a different or modified door design.—GSV