Darryl Seland 0000-00-00 00:00:00
ARM-FREE PROBE “HANDY” TOOL FOR QUALITY INSPECTION Portable device combines video camera, advanced imaging and optical triangulation techniques in a fully integrated product. BY DARRYL SELAND, EDITOR IN CHIEF The Creaform (Levis, Quebec, Canada) HandyPROBE is a handheld, armless probing device with a wireless data-transmission process that allows the user to move freely around a part. Its portability makes it possible to inspect or reverse engineer simple parts to complex assemblies, with precision—whether employed in a lab, on the shop floor or off-site. “The HandyPROBE is used the same way as other portable CMM or manual CMMs,” says Jean-François Larue, Product Manager of Creaform. “Points are taken using the probe and the 3-D coordinates of these points are used by the software to compute the parameters of geometric entities— the center and diameter of holes, planarity, angles—and compares these parameters to the theoretical values coming from blue prints or CAD files.” The HandyPROBE also is supported by all standard metrology software, such as PolyWorks, PowerINSPECT, Geomagic, Verisurf and Metrolog. “For customers already accustomed to such software, it’s really easy to switch from the previous solution to the new HandyPROBE with virtually no training needed,” says Larue. Additionally, the unit’s automatic alignment through optical reflectors allows for the probing of many identical parts in rapid succession. “With optical technology, it is possible to measure and reach the highest achievable accuracy in shop floor conditions, as the system is able to track the part and the probe [Creaform’s TRUaccuracytm technology] at the same time,” says Larue. However, there are limitations, the same limitations as with all optical technologies—it’s not possible to measure directly behind something as lines of sight must be cleared. But, as Larue points out, “it’s so easy to move the optical tracker all around a part—which is continuously tracked, preventing alignment loss—to make the measurement on all sides.” The performance of HandyPROBE in less-than-ideal conditions is also helped along by the fact that the HandyPROBE does not require a rigid set up. “Vibrations coming from trucks, moving cranes or machining centers, for instance, have no impact on the accuracy of the measurement, which is quite a revolution in the field of QC,” says Larue. “Arms, just as mechanical technologies, need a rigid setup to provide a good accuracy in a factory environment.” THE DEVELOPMENT OF THE HANDYPROBE The true innovation of the HandyPROBE, according to Larue, is related to the combination of video camera, advanced image processing software and optical triangulation techniques, like photogrammetry, in a fully integrated product. “One of the main challenges [in developing the HandyPROBE] was to reach the level of accuracy required for QC applications. For example, reaching 10 ìm requires a 250 billion-pixels camera,” says Larue. “Needless to say, such a camera doesn’t physically exist and only highly advanced and very innovative software can help to reach the some tens-microns accuracy reached by the HandyPROBE.” According to Larue, the HandyPROBE is the results of more than 20 years of development and innovation at Creaform and international research centers. “At first, the idea was to take accurate 3-D measurements where it was not possible to setup mechanical CMM. The challenge was to use only video cameras to make the measurement, says Larue. “Luckily, photogrammetry had already been invented, and it made it possible to take such measurement using an argentic camera. It was possible to reach the necessary accuracy, but the process was very slow.” At the same time, computers were becoming more and more powerful and image-processing techniques were making huge progress. “The way was paved for the development of an optical portable CMM,” says Larue. “Development started in the 1990s in research centers in France and Canada and a first generation of portable optical CMM was released in 2005 by the French company ActiCM, which was later acquired by Creaform in 2008. The first version of the HandyPROBE, taking advantage of all the innovative knowledge developed by Creaform for the Handyscan 3-D lineup, was released in 2009.” THE RESPONSE TO THE HANDYPROBE Larue admits that, at first, QC operators and managers, who were more familiar with mechanical technologies, had to be convinced that optical technologies such as HandyPROBE were at least as accurate as other mechanical technologies being used in QC at that time. “Fortunately, and at the same time, other optical technologies like laser trackers, photogrammetry and optical scanners were having increased success in the most demanding industries, like aerospace,” says Larue. “The era of optical technologies had begun and will probably last a while.” HandyPROBE is currently used by leading companies in aerospace (Airbus, Pratt & Whitney, Snecma) and the automotive industry (BMW, Volkswagen, GM, Honda) for various applications from sheet metal to plastic parts, castings, machined parts control, tooling and jig control and adjustment. For more information, contact: Creaform 5825, rue Saint-Georges Levis (Quebec) G6V 4L2 Canada (418) 833-4446 www.creaform3d.com
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