Tuesday, July 17, 2007

Not that bad after all...

Here is the story of "how things went for us"

On Thursday morning, the sub was working great but we were still unable to complete all the stations.
Here is a description of each stations:

1st : find and pass through a submerged gate
2nd : find 2 flashing buoy, dock them to release them
3rd : find a pipeline on the floor, follow it
4th : find a bin near the pipeline, center on it and drop a marker on its center
5th : locate a treasure identified by an acoustic beacon, to grab it and to surface with it INSIDE the recovery zone.

So on thursday, we were able to complete 1, 2, and 5 (surface in the recovery without the treasure). The important point to know is that we were able to complete more than that in Montreal but the setup in Montreal was not exactly the same so we had to adjust some parameters in the mission.

We have been working hard night and day on thursday, friday and saturday to finally qualify on sunday morning. Before the qualif, we were able to pass the gate, release the buoy, follow the pipeline, center on the bin, drop 2 markers in the bin and to go get the treasure to surface. But during the qualif, while the submarine was going to get the treasure, the vision system got a false positive and thought a treasure was located under the sub. The hydrophone system thought the sub was not over the acoustic beacon but the vision system has the last word :) The sub tried to grab that "not real treasure" and then surfaced a few feet away from the real recovery zone where was located the real treasure.

We decided to keep that run because we knew that with a run like that, we would qualify for the final run.

On sunday afternoon, for the final run, our hydrophone system was not working for an unknown reason. So we were unable to recover the treasure. We bumped the buoy again, followed the pipeline, went over the bin, and when the software triggered the marker droppers to drop markers in the bin, the PC died... So this final run gave us the 3rd place after University of Florida and University of Rhode Island.

Post mortem:
Dead PC: We don't know why the PC died but we think the marker droppers drawn to much current when they tried to drop at the same time... It's weird because the droppers are on a protected circuit... But according to the video recorded from the bottom onboard camera, the PC died while the sub was centered on the bin.
Hydrophone: We need to connect the ground of the hydrophone board to the water. We found out that this wire was broken. It's why the hydrophones stopped to work just before the final run.

It has been really fun to compete again and we are proud to bring back the 3rd place even if we were aiming the first place.
We learned a lot about how things can go wrong even when they have been working great for a long time. We also learned about how to work as a team and how to make the team work efficiently.

I don't have photos right now but we will put some on the SONIA's web site soon.

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