VT AUVT

First off, I am very sorry that we haven’t been able to update in the last few days. I know a lot of you were reading regularly, and I led you to expect news. I was under the impression that we would have an Internet connection while we are here, and while that assumption was technically true, our connection is very unreliable and slow at best.

Connectivity issues aside, we have been very busy the last three days here. We got off to a slow start on the first practice day (Wednesday), because we had a long to-do list when we got there, and it didn’t get much shorter. We first tried to fine-tune the ballast to make sure Barreleye could dive, then we tried to get the camera to work. Even though we thought the camera had been working, Ben discovered a flaw in the method we were using to interface it with the Simulink code.

While we worked on the camera problem, we decided to test the program for going through the validation gate. We prepped Barreleye and threw her into the testing pool. Soon after everything was set up at the pool we discovered that she wasn’t connecting to the network and we couldn’t run anything! Thinking it could be caused by an automatic routine maintenance routine, we left it for a while and had dinner.

We came back to find no improvement, so we borrowed a monitor from the neighboring team and hooked it up to the AUV. We were shocked to discover that it wasn’t a software problem at all and the computer wouldn’t even make it past POST (power on self test, or the first bootup screen)! Not knowing what to do about this unexpected and time-wasting problem, we took out the e-rack and hooked it up to external power. It worked! For some unknown (at the time) reason, the problem had magically fixed itself.

By that time we had used up all our time for the day, do we packed up and returned to the hotel. Although we hadn’t even put Barreleye in the big Transdec pool, we were optimistic that we could make it through the gate and decided to make it our top priority. Even so, we decided that we were too tired to get any more work done and went straight to bed.

This morning we all got up and headed back to Transdec for day 2 of practice. Today was the last day to pre-qualify, so we knew that we had to make it work well enough to get through the gate. The first thing we did after we unloaded the van was put Barreleye in the testing pool and test our ballast and our straight-line navigation code. After a little tuning it seemed to work fine, so we went to sign up for a practice time slot in the big pool.

Imagine our dissapointment when we discovered that we would have to wait five hours for our practice session! Since we didn’t want to touch the code that we had working, we just put the batteries on the chargers and had some breakfast burritos. We eventually realized that we needed to work on something useful, so we all set to the next items on our to-do lists. Everyone worked on various things for a while, and we talked to a lot of people about Barreleye and underwater robots in general.

At some point during all this, we encountered the same computer problem we had yesterday, so I set about debugging it. I eventually found that if I turned the motor controllers off before I turned the computer on, it would work. This approach requires that we turn on the motor controllers seperately via (somewhat unreliable) software, but it works.

We finally got called up for our run in the big pool, so we hastily threw in the batteries and ran the wagon all the way around to the launching dock (our booth is on the opposite side of the facility). After briefing the diver on how to handle Barreleye, they hoisted her over the rail and into the water We had tested our network on the competition side of the pool, but the practice side is on the other side of the bridge in the middle, which caused a lot more interference. We weren’t able to start the run, so we had to run back around and grab our router. By the time we were set up my laptop had crashed twice and we were 15 minutes into the half hour session. Since nothing else could possibly go wrong, we asked the diver to point Barreleye at the validation gate and hit the GO button.

Barreleye smoothly ventured straight into the green Transdec waters, only to veer to the right and miss the gate completely. We had the diver retrieve the errant bot and set about trying again. I made a last second decision to ditch the “smart” code and aim for it manually. The first two times I tried running the old program the AUV would turn sharply to the right, at which point Ben corrected a rather stupid erreor on my part. After replacing the values we were testing with in Blacksburg with new values for the Transdec pool, we got Barreleye headed off in more or less the right direction. We fine tuned the heading, and made one last run with Dave (the manager/official) watching. We watched Barreleye slowly but surely make her way in the general direction of the gate, and after some worriment on our part and some autonomous course corrections, she finally made it through!

We later discovered that we were the 17th team to pre-qualify out of 23 teams to make it through the gate. Elated and educated, we returned to out booth and set about making the program more robust. After a few more hours of coding we threw the AUV in the testing pool again and started playing a strange version of pong with it. We had several of us at one end of the pool and we made Barreleye drive to the rest of the team at the other end, and then back again. At one point, She had just hit the bottom of the pool when another team’s bot passed straight over her in a near miss. Several minutes later, yet another sub interfered with the compass and we nearly rammed it twice.

We decided that was enough for one day, so now we are back at the hotel working on the camera and preparing for qualifying and static judging tomorrow.

Be sure to check out the video updates on the competition website starting tomorrow afternoon (EST)!