In a previous generation of the system, a handheld camera system was placed at the inspection location, guided by the laser. The new generation LASERVISION inspects the material placement from a mounted system. “The wing skins of Boeing’s 777X are our largest application at 100 feet long and 20 feet wide at the root,” says Blake. “We view the material as it is placed by an automatic fiber placement robot. With our software, interconnectivity enables our LASERVISION system to stop the process of a robotically built part if the variation is unacceptable.”
Blake notes that inspection time is reduced and the potential for human error is replaced with computer-driven analysis and accuracy. “We have found problems that our customers did not even know they had,” he says. “We were able to prevent some potential part failures.”
Blake believes future applications will incorporate artificial intelligence and deep learning to build and analyze images captured by LASERVISION to create “classifiers” of good and bad parts. “Using deep learning fed by the thousands of images we’re now creating, resulting algorithms will help LASERVISION reliably recognize if the image it is fed is acceptable or unacceptable,” he says. “Composite parts manufacturers will be able to use the images collected by LASERVISION to apply feature recognition and statistical processing to improve automated inspection even further.”
According to a peer-reviewed study of non-destructive testing methods for composites materials by Saeed Gholizadeh, (Structural Integrity Procedia 1 (2016) 050-057), ultrasonic testing – whether pulse echo or through transmission – is still one of the best methods to analyze composite parts.
Classic ultrasound techniques require a composite part to be immersed in fluid, such as water or gel, which is restrictive when evaluating large parts. Newer methods of ultrasound evaluation include dry and non-contact approaches that take images without loss of signal strength.
“DolphiCam is an ultrasound NDE system with a dry, silicone-rubber stand-off nose at the end of the probe. It does not require a coupling agent. The operator simply walks up to the part, compresses the nose to the part and takes the image,” says Dorworth. “When I was first introduced to DolphiCam, I plugged in the software, plugged in the instrument and a standard, and started inspecting, receiving green ‘go’ messages or red ‘defect’ messages within minutes.”
Another alternative to “wet” ultrasound comes from the Ultran Group. Ultran offers non-contact ultrasound systems particularly for porous structures or structures incorporating honeycombs or cells. The technology increases the efficiency of its transducers through a proprietary gas matrix piezoelectric (GMP) material for a non-contact environment.