Cooperative Autonomous Aquatic Vehicles (DYNAR)


>>The Harvey Mudd College Clinic program
pairs teams of students with a sponsoring organization to spend a year working on a project posed by the sponsor.
We have clinic programs in mathematics, computer science, engineering, and physics, as well as a Global Clinic program. In many cases our teams are interdisciplinary
such as the DYNAR team, which has students from mathematics, computer science, and engineering.>>The goal for this year’s DYNAR team was
to design mathematical algorithms that would implement a search strategy to find
four unknown targets. The teams tested the strategies in computer simulations then executed them in water using small
toy submarines that are controlled and tracked by cameras and a computer.
>>Our first step was to simulate these algorithms going on in a simulated environment.
Since we’re interested in the question of how they can search the space,
we just looked into several types of algorithms that would allow them to move around
looking for targets.>>We have a PVC pipe here with
markings at certain intervals. So we’re going to place that at known locations
in the tank. We have little Xs on the tank wall.
And then take pictures from the bottom and from the side. And then
we can actually record where those markings are and then figure out a way to get from a certain coordinate in a picture into
an actual coordinate inside the tank.>>Using these webcams that are set up
both on the side and beneath the tank you can see these 2D pictures
that they take of that 3D tank environment From those images we could use blob-detection
software that pinpointed where the sub was.>>We also have colored electrical tape
on the submarines. So we have pink on the front, red on the back,
or vice versa. And the vision tracking system can pick out
those blobs of color and from that figure out which way the sub was pointing which tells us how we need to point it to get to a target.>>So we’re working with these cheap little
toy subs. They’re about 40 dollars. They are remote
controlled. And we’ve actually taken apart the remote
control that comes with the submarine and when
you take it apart, you end up with a bare circuit board. So we’ve taken those boards,
soldered a bunch of wires on them in the same spots that the joysticks move, so
we can basically convince the remote control that there is someone moving the joystick
by sending electrical signal. The big computer can send control signals
to this remote control board and then it goes through this blue wire, up over the duct and
down to the bottom where we actually have antennas taped under the tank.
So we can control the subs from the computer.>>What the computer would do is to tell the sub to follow that path and in so doing it just
needs to get to this next random point and then over to this random point and then
maybe this one right next to it or on the other side of the tank.
Those commands were to tell the sub to get to these points automatically
without us having to use the controller or do anything with the keyboard. It was just go, and the sub would automatically start searching.
>>As the project progresses we’re going to be including more sophisticated sensors and tasks. We’re also going to be combining stationary sensors with mobile aquatic sensors.
Because the project involves a collaboration between students in mathematics, computer science, and engineering, the students learn to cooperate and communicate across disciplines. For the sponsor,
Clinic provides valuable research and development and the students come up with quite creative solutions.

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