Servo - August 2008

Rhyme of the Modern Submariner

points for waterproofing were the electrical connections, of which there were not too many. There were four connections between the camera, light, and tether, and six connections between the motors and the tether. The kit provided ample materials for waterproofing in the way of epoxy and self-vulcanizing rubber tape. A couple layers of each did the trick, even though the tape was not exciting as we had anticipated given the name — apparently the vulcanization is pretty low key.

Our previous description may have made the construction of the ROV seem like a breeze but, in fact, it took several weeks of meetings. So when it finally came time to test the bot, it was very climactic. Our first tests were to see if the motors all functioned properly, and they spun the propellers so quickly that we were eager to see how zippy the bot would be in the water. It was also exciting to see the light turn on, but we had to find a monitor so we would check the camera. We didn’t have any extra monitors sitting around, so eventually we hooked it up to the television in our dorm room (the ROV comes with an RCA plug for output to a monitor).

The camera was downright impressive. It was black and white, but the resolution was excellent and the LED cluster provided perfect lighting. We have worked on other robots with cameras like the POB robot, but the acuity of the ROV would impress any optometrist.

It might sound like a wacky idea, but the residential life office of our beloved Warren College has large plastic laundry carts for students to cart stuff around in (probably laundry, most of the time). It was a bit awkward to make the request to our college residential life if we could use a laundry cart to fill up with water and test a robot in it, but thankfully they are very accommodating of our robot related idiosyncrasies and gave us the go ahead to give our ROV some swimming lessons.

The small scale of the ROV made testing in the laundry cart a lot less awkward than it might sound. Before taking the plunge, we equipped the bot with an ROV’s equivalent of floaties — floral Styrofoam that was included in the kit.

Our moment of truth turned out to be a moment of triumph, because the ROV worked in the water so well that it seemed like a fish out of water before. We had to adjust the buoyancy with some rebar for ballast and more Styrofoam for balance, but after just a few tries we had an ROV sitting serenely in the water with neutral buoyancy. The kit also includes Styrofoam bits to adjust the buoyancy of the tether, which led us to conclude that the folks at !nventivity really did think of everything.

BRYCE AND EVAN SHOW THE LIGHT AND CAMERA.

Southern California Fly-Of f

Adventures With a Laundry Cart

Until now, the MATE Competition had been only a far-off goal, but

shortly after our laundry cart adventure we had to meet a deadline that had the potential of disqualifying us from the competition. Our team was registered for the international championship, and the MATE organization required that all teams registered for the championship prove they have a working robot beforehand. To do so, we had to attend the closest regional competition to undergo a simple safety inspection and to show that our ROV could ascend, descend, and move forward, backwards, left, and right.

The closest regional for our team was actually at UCSD, held at the Canyonview West Pool in our very own Warren College. We showed up to the regional with confidence — the robot certainly wasn’t finished, but after our laundry cart test we were sure it could handle the qualifying test.

Our little ROV had no problem passing the test, and it was exciting to give the little bot a chance to run free in a big pool. It was also exciting to

Everything on the ROV worked like a charm on the safety of dry ground, and despite these encouraging signs we have to admit that we were a little apprehensive about putting it in the water. At first, we wanted to test the robot in one of UCSD’s on-campus pools, but it turned out to be a hassle to reserve the time and space. Plan B was pretty much what you might expect. If we couldn’t test the ROV in a pool, we’d go with the next best thing — a laundry cart.