| Author(s) |
Jerald Edward Jones, Valerie L Rhoades, Mark D. Mann, Terry Surufka, James Dydo, Lisa Elles, Maurissa D'Angelo, Nicholas Braniff, Mike Buelsing, Todd Holverson, Susan Fiore |
| Abstract Scope |
“Mirror Welding” as it is often called, requires the welder to hold a mirror so that he/she can “see” around an obstacle in order to produce a weld in a location that is not visible by the welder. In smaller ships, or more complex larger ships (i.e. Navy), as well as in large structural applications, this situation can occur with some degree of frequency, such that a welder who has experience welding by looking at the weld in a mirror is often called upon to perform this “circus trick” (to which it is often referred). It is that, a trick, even though it is a serious weld, holding a welding torch in one hand and a mirror in the other and then trying to weld in a location that you cannot see, except in the mirror. If you move the torch right, your perception is that you are moving to the left. Nothing about this task is “typical” or “ordinary” and many people are incapable of performing a mirror weld. Even people who have perfected this skill often have difficulty making ideal welds under these circumstances.
Until now, mirror welding was a skill that most shipyards had, but only one or two welders. This proposed technology will enable all of the skilled welders in a shipyard to fairly easily become skilled at “mirror” welding. The goal is to allow the welder to digitally “adjust” the image so that it is the most comfortable for them to use for welding. The image will be able to rotate, flip vertically or horizontally, even be shown as a “mirror” image for those welders who are already highly skilled “mirror welders”.
The principle cost of “mirror” welding is not only the cost of the welding, it is also the cost of repair and re-work. Those welds made in tight or uncomfortable positions while holding a mirror – both hands occupied – are difficult, at best, even for the most skilled. It is not unusual for there to be a momentary problem with reach, or visibility, or body movement, which can result in the formation of a weld defect.
The technology of using video data, rather than the current practice of through-a-dark-lens viewing, opens up the possibility to significantly enhance the entire field of manual welding. Today, the welder must get their head into a position to see the weld, which can be uncomfortable and awkward. If the lens is dark enough to guarantee no eye damage it can be too dark to see all of the details of the weld joint. Because of the great proliferation of video camera and video processing technology, especially Artificial Intelligence based methods, including Augmented and Virtual Reality, the software and hardware can have very significant image enhancement ability. A Navy ManTech project EOC-PSU produced an analysis that showed that using a video equipped helmet could save as much as $4M annually for a typical shipyard, producing Navy ships.
The project has successfully embedded a very small camera (in a Miller Bernard BTB MIG Gun, )T Series Straight Handle, 400A, 15 ft., Medium 60° Fixed Neck, 1/16 in. – a common heavy duty welding gun). The camera is cooled and protected from spatter, and has demonstrated the ability to transmit a high quality, high speed video image of the welding wire, welding arc, and weld pool, as well as key features of the weld joint.
Successful butt and fillet welds have been produced and provided a excellent video images. The video images are displayed on a video screen which has been positioned in the welding helmet. Welds produced with this system meet basic welding quality requirements, for shipbuilding. So, it has been demonstrated that a camera can be integrated into a welding torch, that camera can transmit video images which are sufficient in order to produce a weld, and, that the “lag” in the video image is small enough that the human welder can produce a weld which meets the quality requirements.
Finally, the system can provide a complete video record of every weld, which is stored in the welders helmet, and is downloaded at the end of the shift while the batteries in the helmet are being re-charged. In addition, a modified ArcSentry weld parameter monitoring system is also included in the overall welding system and the real-time parameter data can be displayed as a function of time and/or distance along the weld to facilitate a weld quality assessment of the weld. |