Video - UAV Boat Project Sinks - Propeller and GPS Work Underwater

SuperCricket

So here is a video of my summer long UAV project.· I decided to do it in a boat instead of a plane.· A few months later and nearly $500 in electronics in the thing and I was ready for the first test.

You can see the boat completely dissapeared underwater.· However one cog was strictly for motor control and its directives to stop the motors were if the boat reached its destination waypoint, or the GPS lost signal.· The ole Parallax GPS worked under water long enough for it to keep firing the motors until the boat popped back up from the surface.

The uController SD card kept logging the whole time under water too.· Not sure what all is fried yet.

http://www.youtube.com/watch?v=VdM_h-cGjBo

UAV IS HARD.· Enjoy!

Tired2

Good to see another propeller user in Texas. I'm at Texas State University in San Marcos (School of Engineering).

That sucks your boat sunk, maybe a larger hull would stabilize a bit better... I'm no boater, but even those small lake waves on such a small boat would want to flip it even without the "gps mast".

Maybe you could put a stabilizer on the bottom with a weight about a foot under water or so to counteract the sway from the mast.

Oh well, hindsight is 20-20.

You are just a few large servos away from automating your real boat, if you were so inclined. [noparse]:)[/noparse]

EDIT: Thinking about it, since you have to have that battery weight anyway, why not move it down below the boat in a water tight enclosure? A little PVC, some silicon, and you could power your boat from a ballast under the water. You'd get double returns on your "investment", since you'd be lowering your center of gravity by getting the battery out of the hull, and by putting on an underwater counterweight. Performance would take a hit, but I don't think that is the main idea here. Like I said, I'm not a boat guy, but I know how summer projects are... desperation ensues.

Post Edited (Tired2) : 7/30/2009 1:55:06 AM GMT

parts-man73

Maybe outriggers to stabilize it?

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Brian

uController.com - home of SpinStudio - the modular Development system for the Propeller

PropNIC - Add ethernet ability to your Propeller! PropJoy - Plug in a joystick and play some games!

SD card Adapter - mass storage for the masses Audio/Video adapter add composite video and sound to your Proto Board

CounterRotatingProps

Kyle,

good attempt - and thanks for sharing even in the mistakes!

Here's the one rule your design seems to have left out:

Weight's always end up below floats.

Hope you'll be able to salvage the best!

[noparse][[/noparse]EDIT: Nice mathematics work, BTW.]

Cheers,
-Howard

(Working on a submersible - see over in the robotics area.)

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Post Edited (CounterRotatingProps) : 7/30/2009 1:20:01 AM GMT

ElectricAye

Hey, awesome first try! Sorry it deep-sixed itself, but there's no better place to learn than the real world.

Keep at it and good luck.

Spork Frog

Good to see that at least some of it worked! Thanks for sharing this, I believe this may be useful for future boat UAV builders. Very fun to watch. Amazing that thing still looks like it mostly works as well -- very clever with the SD logging.

Nice yacht, by the way.

Phil

Roger Lee

Thanks for sharing your project.

2 cents worth: Rather than redesign this boat, is it possible to tow the GPS in another boat (raft, float, tube,jet ski... ).
If the boat was stable without the heavy mast this just might work.


Roger

Jay Kickliter

This is one of those projects I've thought about but haven't started. Have you thought about using a small dinghy and an outboard?

My idea has been to use my 8' PortaBoat and 3.5 HP outboard. That thing so stable. I've crashed into things in the middle of the night several times with no problem, on account of its somewhat flexible materials. With me in it it planes an 10 knots, autonomously it could holds a lot of gas an go a long distance.

photomankc

Can you compute your course heading by using the GPS fix points instead of the compass? The reason is that 2-axis compasses are notorious for being flaky with even small deviations from level. The ones in my handheld units have to be held perfectly level or you get very big swings in heading. I'd use the compass to just get a basic cardinal direction idea then start moving and make my real course correction changes based on the calculated heading from one fix point to the next.

Very neat project! You need a keel or outriggers with that weighted pendulum up top though.

WNed

Dude, cool project. Thanks for sharing. It's easy to post successes, but not so much with the other, even though we usually learn a lot more from the not so successful attempts.
If you wanted to build a UAV (aerial vehicle) originally, you should know about weight and balance. Boats use w&b too. Your mast should be mounted at center of balance. Use a counter-weight on a keel beneath the boat. That will serve the purposes of stabilizing the boat in both roll and yaw, as well as counteracting the effect of the mast.
Good luck!

Ned

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"They may have computers, and other weapons of mass destruction." - Janet Reno

Timothy D. Swieter

Excellent project Kyle. I hope you can resurrect the electronics and get back to work. Your project looks like a lot of fun in trial and in error.

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Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
www.tdswieter.com

hinv

Instead of the mast, you might want to experiment with some magnetic shielding on the motors. It may be as simple as some cheap palette strapping wrapped around them.

Just my 10 bits worth.

Doug

QuattroRS4

Nice idea .. shielding and a bigger boat might go a long way though..

Regards,
John

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'Necessity is the mother of invention'

'Those who can, do.Those who can’t, teach.'
'Convince a man against his will, he's of the same opinion still.'

·

RinksCustoms

weight and balance.. looks to me like you did an excellent job on the waterproofing, but the CG appears to be about 2-4" above deck, its like supporting a chevy 5.7L V8 small block 5' above your real boat on masts. If you were to locate the GPS antenna on the deck with even a plastic wallmart bag over it, should do the trick and you'll be following it all day out on the lake. Very cool project for automation for people out on the lake and have some kind of medical problems and need to get to shore or if theres like some kind of medical station dock, u can have the prop automate the boat to drive slow to that dock while sending out a radio distress signal, or if the boat catches fire, you hit the BIG red button and the prop being able to run off of two D cells, can send an S.O.S. via radio freq to the nearest emergency responder with the GPS cordinates, & repeat the GPS cordinates over the radio with an MP3 chip/SD card... or have the MP3 play a basic msg telling emergency workers to tune to channel 3 on their TV's for the cordinate information.

Very cool project with big possibilities! Keep at it,
Michael

post edit:
Noticed you didnt have EMI cans over the motors, they might allow you to put the GPS right on the deck. U may be able to solve the problem of EMI with a sheet metal (steel pref) cover for your deck. An alternative WITH using the mast idea, is to implement an accelerometer or heli gyro about half way up the mast to counter the roll rate of the boat when turning with a slightly larger rudder/servo. For the compass... a two axis swing tray would keep the compass pretty level, but then youd need to dampen the oscillating motions enough. Easiest way to stabilize is with your suggestion of outriggers, say like 12" from each side of the boat.

ALSO, i have a 48" R/C boat initially made for nitro but it has no guts/paint. If your interested in a bigger boat.. PM/email me.
i32.tinypic.com/2chqgq9.jpg
i32.tinypic.com/4ta5xx.jpg
i32.tinypic.com/28moe95.jpg

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Quicker answers in the #propeller chat channel on freenode.net. Don't know squat about IRC? Download Pigin! So easy a caveman could do it...
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Post Edited (RinksCustoms) : 8/5/2009 4:13:42 PM GMT

ceruleanplains

I haven't yet got into the Propeller, but I'm working on getting 2 BS2s I have on hand into the game for my project. I'd be interested in hearing some suggestions on the architecture.

For your design, perhaps you'd consider catermeran hulls (i.e. three hulls) instead of just some floats. You might do well to just use smaller scale boat hulls to minimize your drag. Did you have the opportunity to try your vehicle in a pool or smaller test setting? Perhaps alternatively you could ferry it on a RC car for testing of your subsystems?


I have my own stability problems I'm trying to solve with some more control surfaces. I'm trying to retrieve some objects from the bottom of a pool. I'm using the BS2 to control a PS2 joystick that interfaces with a custom 3-motor H-bridge.

Here Inky is struggling against the tether to pick up a ring on the bottom.
[noparse][[/noparse]youtube]

This time it does better after it's been straightened and the retrieval hook is tightened and lowered.
[noparse][[/noparse]youtube] [noparse][[/noparse]/youtube]

My stability problem is largely about the center of gravity since my thruster clearly is misaligned. However the weight of the ring shifts it across the CG in the opposite direction. So my proposed solution is a 2nd vertical thruster. Unfortunately I'm running out of control lines. With PWM I'll need more. So I'm looking to a combination of perhaps 2 BS2s that I have on-hand with a Propeller chip.

So going forward, I'm going to redesign the frame a bit to hold two vertical engines and install an accelerometer (from Smart Sensors) , an onboard camera (potted in epoxy), LEDs (for both lighting and strobe), and a compass (from Smart Sensors) for semiautonomy. The objective is that the robot will detect the ring and alert the operator with a strobing LED. The robot will also have finer attitude control by using control guidance to PWM the motors to maintain a heading. I will also attempt to do some recon & retrievals autonomously or at least have some of the end-game autonomous with myself setting up the rendevous with the target.

Post Edited (ceruleanplains) : 8/11/2009 4:09:03 AM GMT