Ultrasonic Remote Inspection: Easy as 1, 2, 3

Real-time composite damage monitoring is so simple that virtually anyone can do it with the new Imperium Acoustocam - an ultrasound imaging camera that works much like a typical consumer digital video camera.

With composites being the main material used in Boeing's 787 Dreamliner, as well as many other new-generation aircraft, a new concern has presented itself. Detecting defects is much more challenging on a composite wing or fuselage, because there is often no visual indication as there is on aluminum structures. The problem may be invisible from the outside, yet the inside may have a serious defect.

Boeing, foreseeing this problem, has entered into a project with Imperium Inc. of Silver Spring, MD, to develop an ultrasound imaging camera that will identify these defects in composite and other material structures. The camera is called the Acoustocam 1500, and the intention is to make it so simple to find material defects that anyone, anywhere can perform the inspection.

1. The Scenario

"What happens if you get 200-some people sitting on a plane, and somebody backs a truck up into it," poses Bob Lasser, president, Imperium, Inc. "It could have damage to it, but you can't see any of the damage from the outside. With the new materials like the composites, it's all on the inside." In cases like this, airlines must ask themselves whether it would be economical to take the plane out of service, fly it to a depot facility and have the experts sort it out, or whether the plane is safe to fly commercially.

The wrong decision could prove to be a very costly one. With the Acoustocam, the decision is much easier to make.

2. The Technology

The Acoustocam adapts the technology of a regular digital camcorder for use with ultrasound.

The high-resolution output can be monitored wirelessly by technicians, who then decide whether the plane is suitable for flight, or whether it requires immediate maintenance.

The 4 lb camera head is basically a probe that sends an ultrasound picture wirelessly to a hub where the technician is able to view a digital image of the inside of the composite structure to determine if any holes or dents are present.

This process is much easier than typical ultrasound inspection because it is not necessary for a highly trained specialist to perform the inspection.

"The bottom line is we're trying to put these in the hands of users that traditionally haven't been able to use it, because it's simple, easy-to-use, and it's low cost," Lasser explains. "Most of the devices that are used in aerospace in terms of non-destructive testing require a pretty specialized trained technician."

The Acoustocam is lightweight and easy to use.

3. The Analysis

As a technician receives the image on the screen, he or she can guide the plane-side operator in real time where to place the probe next.

Ultrasound waves do not travel through air, but rather through water or metal. To use the Acoustocam, the operator must spray a gel or water on the part to be looked at, and place the hand-held probe up to the wing or fuselage and scan around. The image is then shown on an LCD, displaying any internal voids that may be present.

"The reason that Boeing chose us is because our ultrasound is far different than any other kind," Lasser says. "It's much simpler to use: what you see is what you get. You could be a super-user in less than a day." Current alternative technology requires an ultrasonic transducer that outputs an oscilloscope, which requires a certified specialist to interpret. On the other hand, the Acoustocam actually sends a full-field, realtime image that anybody can understand, according to Lasser.

The idea is eventually to get it into military hands so that 18-year-old soldiers with minimal training in this area are able to do plane-side inspections and transfer to the output to technicians.

Plane-side inspections are easy with the Acoustocam.

Boeing helped to fund and certify the remote technology. They also funded several trial adaptations and wireless trials so that the video output is tapped into a local area network.

The Future

Currently, the Acoustocam is available for in-process inspection on shop floors, but Lasser expects them to be in the hands of airline personnel within the year.

"We also have several programs with the government right now to further develop them - make them smaller, more robust, do application-specific embodiments, etc.," he says. "We've gotten great response so far." With the ability to put the Acoustocam in the hands of a line mechanic or another on-site individual and have a technician wirelessly view and assess the damage, airlines are now able to make a much betterinformed decision when minor accidents take place.

Imperium, Inc.
Silver Spring, MD
imperiuminc.com