CompositesWorld

FEB 2018

CompositesWorld

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FEBRUARY 2018 40 CompositesWorld WORK IN PROGRESS mirrors. From a second aperture, a high-resolution digital camera with a 300-mm lens is also steered by two mirrors to capture pictures of the in-process material deposition." e high-definition images are precisely located in three dimen- sions, because the camera and the laser work within the same coordinate system, "transformed" or registered to the tool and head locations in space. e 3D location of each camera pixel is identified by the user interface. Image sets are conjoined to create a complete image of each ply over the entire part. Image resolution is high enough that ply boundary locations can be measured auto- matically from that image. Electroimpact says that camera images of ply boundaries have been qualified to be within ±0.060 inch/±1.5 mm of the true position in a mobile (i.e., gantry-mounted) setup. Leveraging big data Meanwhile, the laser profilometer projects a line onto the part surface during material laydown, and its built-in detector array measures the height of more than 1,000 discrete positions along that laser line, says Cemenska. us, it detects a 2D profile of the surface. As the profilometer rides along with the head during material deposition, it creates, in effect, a 3D surface profile. As explained in two recent white papers authored by Cemenska, Rudberg and colleagues Michael Henscheid, Andrew Lauletta and Bradley Davis, the profilometer's laser line spans the seams between tows, measuring the width of any overlaps and gaps as layup proceeds. ese profilometer data are integrated with the data from the camera and the part programs, as well as operator input, within the inspection user interface; the interface builds a ply-by-ply 3D model of the part as production progresses. Recognition software measures the locations of features from the vast amount of camera image data, as well as the raw data array generated by the profilometer, to see tow ends (or ply boundaries), tow overlaps and gaps and identify defects such as puckering and bridging. It then displays these on the 3D model. e user interface and algorithms required to crunch the collected data were devel- oped in-house by Electroimpact software engineers, says Rudberg. (A foreign object detection system not developed by Electroimpact is coming, according to Boeing.) e Electroimpact automated ply boundary inspection system can correctly identify and measure 92% of tow ends on a standard ply, with a mean error smaller than ±0.005 inch and a standard deviation of ±0.020 inch. Rudberg says that overlap/gap measure- ments made with the profilometer, which happen in parallel with material laydown, can be accomplished significantly faster than manual inspection. In case a question about a tow end or a gap/ overlap arises, select images are forwarded to an inspector for assessment on a computer screen in the workcell. Says Cemenska, "We've almost eliminated any manual inspection. If we find that rare case of an error, like a dropped tow, that area is displayed by the LASERVISION's laser lines, and the bad tows are pulled off, if necessary. e machine head is then reprogrammed to conduct the repair." Cemenska adds that in the case of the wing panel parts, many tow ends can be eliminated from inspection, because part edges are subsequently trimmed, which saves additional time. with a high-resolution camera in addition to a laser projector. Supplied by Aligned Vision (Chelmsford, MA, US), the units each work together with a laser profilometer — essentially a small laser that projects a line onto the work surface — which is mounted on the head. All three elements (laser, camera, profilometer) feed data to a user interface supported by computer software algorithms. e Aligned Vision projector box units are mounted in a row on a second gantry beam that operates independently of the head gantry, but typically follows behind it. Rudberg says the configuration minimizes the distance between the lasers and the part, and reduces the angle of incidence. Explains Aligned Vision's COO Matt Zmijewski, "e 777X wing panels and spars are the launch applica- tions for LASERVISION, which delivers two key functions. From one aperture, a laser is projected, positioned by a set of two steerable Read this article online | short.compositesworld.com/AutoInspEI This short Boeing video, taken at the CWC, shows pre-production versions of the 777X composite spar and wingskins | short.compositesworld.com/777XYTvid Read more about a "Real-time automated ply inspection (RTAPI) system: CW's series on automated inspection methods" | short.compositesworld.com/MaassBlog This Electroimpact video shows the layup of a prototype wing spar shape | short.compositesworld.com/EI-WSvid Hufschmied USA 203.988.9426 www.hufschmied.net • Quality without secondary operations • High abrasion resistance • Extremely long service life • Highest process stability – roughing and finishing in one single step • Extreme improvements in cycle time

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