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Autonomous Underwater Vehicle Competition
krugg234 writes "Today [ed. note: well, a few days ago] marks the start of the Fifth Annual International Autonomous Underwater Vehicle Competition. This year's competition involves completely autonomous robots locating and reading bar codes at various depths underwater at a naval base in San Diego. There are some good links on the site to individual competitors' websites to see how different schools tackled the same problem."
Maybe a little more info.
Lasers don't work that well underwater because water distorts light and various wavelengths. The deeper you go for instance, the less natural light would be recieved (less light = more noise).
Plus, most supermarket scanners use a red laser to scan barcodes, and red is one of first wavelengths to fade as you go deeper. Kodak even sells special underwater film that is extra sensitive to red wavelengths so you can take more natural looking pictures further down.
My guess is they are using webcams because the refractive qualities of water makes using lasers more difficult than getting a webcam and some image processing software.
Actually, I'm one of the competitors (I'm typing this from the competition now). The reason that most of the teams use webcams basically comes down to what's available to us students. Most of our equipment is old, second-hand stuff or borrowed from several robotics companies. Actually, the way grocery stores read bar codes was taken into account when we decided how we were going to read them (I wish I could tell you more about how ours works, but I'm sure I'm not the only competitor who reads slashdot!). Also, the camera requires less modification to allow us to home in on the barcodes so that we can read their depths, which is the other objective.