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[on:]

I was have a nosey at the Museum of Flight's website and it occured to me that one could make a solar powered UAV and send it off to circumnavigate the world.
It'd be a bit tricky, you'd have to design the frame carefully to provide lots of lift for minimum thrust, you'd have to balance the power so it's a low load which can run off battery for quite a while (if you sent it over the poles it'd have to cope with periods of more dark than light), that kind of thing.

Then it struck me that a boat would be simpler.  You wouldn't have to worry about the weight as much, you'd need fewer instruments (no tilt, altitude or airspeed sensors) and if it ran out of power it could just sit and wait til it was sunny again, then set off.

Any thoughts?

[Reply #1 on:]

How will it cope with 5~10m high waves?
Curious fish? (like sharks, dolphins.. orca's?)

Also, it'd need some decent power to fight the currents.
But, to continue on the waves thing.. what about storms in general, and what about possible icing?
(planes do suffer from a lot of the same problems, but I reckon to a lesser extent.. the higher you go, the easier it is on the plane.. apart from the potential icing problem)

PS: both sound very interesting.. and very very challenging to get right

[Reply #2 on:]

Nasa needed to spend some millions to that one of those solar powered UAV's to circle the world, so I dont know if it is at the reach of the DIY'ers

[Reply #3 on:]

I was have a nosey at the Museum of Flight's website and it occured to me that one could make a solar powered UAV and send it off to circumnavigate the world.

With enough money, yes, this could be done - the better question (other than to just prove it can be done) - is why? What greater purpose could it serve?

It'd be a bit tricky, you'd have to design the frame carefully to provide lots of lift for minimum thrust, you'd have to balance the power so it's a low load which can run off battery for quite a while (if you sent it over the poles it'd have to cope with periods of more dark than light), that kind of thing.

You'd probably need something big, similar to the Gossamer Condor/Albatross wing area, to have enough area for the solar cells; plus you'd need to find lightweight solar cells. It could probably be done, but it wouldn't be cheap or easy.

If one's goal were just to circumnavigate the world autonomously, then trying to speak with the Rutan's about their Voyager project might open some doors (if you had a good design and some money up front, I'd imagine). Not sure nowadays, but back before Voyager flew it was fairly easy to just walk into the hanger in Mojave...

Then it struck me that a boat would be simpler.  You wouldn't have to worry about the weight as much, you'd need fewer instruments (no tilt, altitude or airspeed sensors) and if it ran out of power it could just sit and wait til it was sunny again, then set off.

Besides the thoughts already given, I think a boat/ship/sub is going to be just as difficult to pull off - as much engineering and monetary sacrifice.

IIRC, drug smugglers have used underwater autonomous subs in bids to ship drugs; I also know that there have been long-range underwater "glider" devices tested (they move forward by sinking and rising), but I don't know if any have done more than tests, or if they are in general use by researchers. I don't think they are solar powered, though (but then again, they don't use a lot of energy). They are suppose to rise to the surface and use satellite communications (likely Iridium or similar) to send/receive data.

There is definitely a market out there for either system...

 

[Reply #4 on:]

Why?
Well, why not?  It's a challenge, I'm not aware of anybody else doing it on a hobbyist scale.  

While I'd prefer to do the aircraft I think a boat is going to be more practical.

I was thinking of a sealed unit that floats, with each component or set of components sealed as well.  It should float even if the hull is breeched so even if it was damaged and the engine inoperable it'd still be recoverable - though that'd need communications to locate it (and an ocean going vessel).   Big waves shouldn't be a problem if it's made to be robust enough to cope with being thrown around.

Currents would be a problem, so the course would have to be carefully plotted to avoid them and the chance of beaching.  Since it's perpetual (thanks to the solar power) I hope it'd be possible to plot a course that would leave it with a decent time margin to charge its batteries and escape from any land.

It would, of course, be fitted with cameras so it could take a shot of any curious marine life and of the stars at night (the only decent proof I can think of).

I would absolutely love to make a perpetual UAV.  I doubt that'd happen though, especially not on a small enough scale for me to not bother air traffic control with.

[Reply #5 on:]

Camera's.. solar panels...
Sounds like you'd have plenty on the outside in harms way  :



Hmmm.. for some reason something struck me... clear acrylic...

[Reply #6 on:]

Aye, the cameras will have windows.

I may build a small prototype after Christmas, see if I can get it working in a lake first, then upgrade to a bay, then a sea, etc.

[Reply #7 on:]

I could see it working, if it was sealed, currents and waves could push it, even far, off course, but that could be corrected by GPS.  Not being limited by a fuel supply means it could just keep on trying and get there eventually.

The hardest part would be not getting run over by an oil tanker or similar large boat.

[Reply #8 on:]

hurry up, I believe there is a price to be won.

http://www.bbc.co.uk/news/uk-wales-mid-wales-11564872

[Reply #9 on:]

I love this idea of an autonomous seafaring vessel. totally doable imo, and i reckon I could do a better job of it than Aberystwyth Uni if I had a budget of 2.5k.

It'd be good to get some sort of short distance race going, put a maximum spend on it and make SPOT position uploading (www.findmespot.com) compulsory for tracking the competitors. This would be very fun.

Olly

[Reply #10 on:]

UltraMagnus, drifting off position is ok as long as it doesn't ground.  It should be ok getting run over, it'd just pop back up afterwards, but it'd probably die if it got hit by a prop.

raalst, I think that's a prize for a sail boat.  I think perpetual automatons would probably be worth a bit once someone cracks it, but it'd have to have satellite comms onboard or it wouldn't have any practical applications.

Thanks for telling me about SPOT Olly, very interesting idea.

[Reply #11 on:]

a tiny sail boat ?  lol, thats pretty fail

I would make an aircraft with/that floats so it can ditch in the sea if it conks out on a cloudy day, and just stay put in the water for however long it takes for a storm to pass (if it lands in one)

maybe plot a course so it lands on beaches or fields or whatever to recharge,  since i thoroughly doubt a DIY'er can make a perpetual solar plane.

[Reply #12 on:]

Small gas engine plane has done it already

http://www.thefreelibrary.com/RnR+Products+Unique+UAV+Airframe+Technologies+Produced+Unmanned...-a050265255

Would solar powered craft be able to go as fast? If not, would think you'd need decent battery capacity to make up for possibly having to deal with darkness longer.

"Utilizing RnR's unique composite hollow core molded technologies, the Insitu Group, the University of Washington and three years of R&D effort culminated with the Aerosonde entry into the history books as the first unmanned aircraft as well as the smallest aircraft to cross the Atlantic."

Or maybe plot a route that follows shorelines so have better chance at recovery after ditching.