Solar-Powered RC Helicopter With Video

Projects General Guidance
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So I'm loosely thinking about a project to fly a video camera. Something along the lines of a robot that flies as far as it can (powered by solar power) and then when it starts getting low on power (the sun starts to set) it lands in a flat location, broadcasts its location and a recent image to a local cell tower and then waits for morning.

I'm pretty dubious on the feasibility of the project, but that aside, what equipment would you recommend? Type of solar panels, type of camera (to figure out a flat place to land and to broadcast an image to a cell tower), method to broadcast to a cell tower, what kind of rotors to lift the whole robot with...?

I'm not too concerned with the final size of the robot, I'm shooting for something that a single person can carry down stairs, probably lighter than 50lbs.

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Are you gonna need a special license for unattended, uncontrolled helicopter of that size to do that?
I'd think you'd need gyrostabilization, plan a flight path to follow to avoid running into obstacles, insurance for when it does run into something and causes harm or damage. Battery back up - charge from the solar panel to start to have some back in case it flies under a cloud.
Not sure you could generate enough power from solar panels to lift their own weight. What panels did you have in mind?

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~Are you gonna need a special license for unattended, uncontrolled helicopter of that size to do that?
That's a strong possibility. This would be a pretty massive undertaking, so I probably wouldn't get to that part of the design until way down the road, there will probably be a few drafts of the design before I'd have to look into that, but that would be something to think about...

~I'd think you'd need gyrostabilization, plan a flight path to follow to avoid running into obstacles
I figured that I could work that in once I figured out how well I could communicate with the cell towers - I'm already limiting myself to a path near cell towers.

~Battery back up
Fair enough, I'd probably dedicate whatever weight I have left over (from the weight budget - propeller lift sans everything else) to a battery storage

~Not sure you could generate enough power from solar panels to lift their own weight. What panels did you have in mind?
Well, from my cursory research, I came up with http://www.powerfilmsolar.com/oem-components.php which give 0.7W for 6g and 40in2, ~$30 per panel. I'm looking around now and the motors seem to suck a lot more wattage than I had originally envisioned, several dozen watts...

Wonder if there's anything I can do with balloons... Helium is moderately priced for that ($50 for 50 balloons). Hydrolysis for Hydrogen seems a bit messy... and dangerous. Though Hydrogen leaks eventually, I'd prefer if this system were self-regenerative or could run semi-indefinitely

Or better yet, using a lens to focus light into a point, heating the air and lifting a hot-air balloon. I could probably rig up a setup to always keep the lens pointed at the sun, the only problem would be getting a big and light enough lens...

Hey, SunSphere solar balloon - bam, strap a computer fan on there for navigation (and maybe one at the boundary to keep the balloon filled - or to refill it up automatically at the beginning of the day). A few solar panels on top for power... I could do some field tests with this easily enough - just leave it in a field and measure the upward force of it throughout the day - that gives me an idea of how much weight it can carry and for how long. Probably don't have to worry about a permit either for a hot air balloon right?

GPS, Barometer, temp sensor, arduino, camera, method to transmit data (still not sure on that one), couple fans (maybe 2 Watts each), a handful of solar cells (gets me ample wattage for the electronics), perhaps a small storage battery.

Thoughts?

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I guess weigh it all, get the e-book, and see big of balloon would be needed to lift it all, then start cutting & taping!
RX transmitter:http://www.robotshop.com/433mhz-high-sensitivity-transmitter-receiver-pair-rxa30.html
Need a baromer with the GPS?
Mini-uino for light weight weight? http://arduino.cc/forum/index.php/topic,69622.30.html boards have been ordered.
Fans are for what?

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Thoughts?

Can't you be satisfied with just blinking some LEDs. :smiley:

Seriously you have some real difficult requirements in your original wants and needs. I think first you need to research the state of the art on various R/C airframes, their power requirements Vs flight duration Vs battery energy density and cost per watt-hour. Only when you have a realistic and approachable airframe platform is it worth even going forward with all the bells and whistles (i.e. ET call home after landing LOL). I'm not saying it's impossible, but it probably is for an individual to finance, design, and build. Maybe if you contract it out to Boeing?

Lefty

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The Japanese launched hydrogen filled paper balloons from Japan towards the USA during WWII.
Around 10% managed to complete the 5,000 mile journey in about 3 days at an altitude of around 30,000ft.
The explosive payload was about 20kg but the 10m diameter balloon had to carry about 450kg of gear, presumably a lot of this weight was the sand ballast.
The control system was based on mechanical timers linked to an altimeter.

As a weapon it was not very successful though amazingly one balloon caused a short circuit in the power lines supplying electricity to the cooling pumps
of a nuclear reactor in the Manhattan project!!!

To get a video aloft using a small balloon with solar power for control and communications is obviously possible.
You might either be able to launch, track and recover as manned hot air balloons do or head for the edge of space like
Joseph Kittinger who made it to 102,800ft in a helium balloon before jumping out and breaking the sound barrier in free-fall on the way down.

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Need a baromer with the GPS?

Typo, barometer

Mini-uino for light weight weight? http://arduino.cc/forum/index.php/topic,69622.30.html boards have been ordered.

I'll take a look at those, I'll need something with some kick since it need to work with a GPS

Fans are for what?

Navigation. In the end I'd only likely use one - for taking air into and out of the balloon. By adjusting the height, I can ride different directional winds, but I'd need to talk to a meteorologist to find out more about what my options would be.

Can't you be satisfied with just blinking some LEDs.

:smiley: Never

I think first you need to research the state of the art on various R/C airframes

I'll be looking into a balloon if I were to actually undertake this. As you've said, an airframe would be pretty much out of the question

had to carry about 450kg of gear

That's freaking impressive, sandbags or not

or head for the edge of space

I've been loosely thinking about that actually. What I'm thinking would be to go as high as possible with hot air, charge a battery during the day and then discharge it over night into a heater to keep the hot air up, thus keeping the balloon elevated. A helium balloon would be good, but I don't think it could last more than a few days, and I'd prefer to do this sustainably if I could (perhaps a month levitating over approximately the same spot).

I can increase/decrease the air in the balloon to control elevation. I could change the elevation during the early morning hours when solar power is readily available. So early in the morning I choose a height that puts me in a wind that goes where I want to go and then for the rest of the day I try to maximize lift, just going up and up and let the battery charge. Then at night, I turn on the heater (I'm thinking a toaster heating element) and do everything I can to keep the balloon afloat.

This sounding any more realistic?

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charge a battery during the day and then discharge it over night into a heater to keep the hot air up,

This sounding any more realistic?

No, not really.
Look at the big propane tanks a hot-air balloon takes up.
Work out the energy density of those tanks (Joules per kilogramme, or BTU per pound or whatever), then figure out the same figure for a battery.
The battery looks pretty poor, doesn't it?