LOW COST UNMANNED SOLAR AIRCRAFT. We did it!!!!!

Ludo91

100 W
Joined
Feb 14, 2011
Messages
123
Location
Milan, Italy
Hey my worldwide located electric powered friends!

Me and a my "crazy projects mate" (Stefano, aka giubi.s) made a solar plane

It is 3 yards of wingspan (2.3 meters to be precise), glassfirbe homemade fuselage and carbon/balsa wing.

28 panels are connect in 14s2p and are inside the wings and on the tail.

Motor is hacker b2015l + maxxon gear 4:1, esc is 18A from hacker.

The panels under the trasparent oracover indoor give us 25 watts on a great sunny day, barely enough to fly, so we have a 3s lipo with a ground controlled switching regulator to make the battery and the panels cooperate.

FLying with such low conspumptions requires an insane precision, so the plane is flown by ardupilot 2.6 (thermopiles version).

We worked on it for a bot over a year, biggest issue was to have the battery cooperate with the panels.

A few days ago we managed to keep it in the air for 142 minutes, wich we think is a great succes and will be improved since that day was very wind and the autopilot was not propely set yet (5 times up from almost ground to limit of visibility and back, a big waste of energy I`d say).

Here are some pics!



















 
Sweet! I think there is a job for you at border partrol. :p

What kind of issues did you have with the panels not cooperating with the battery?
 
Very cool! :mrgreen:
 
That, is so badass:) /has nothing to do with ebikes , awsome. I still want to do a quadcopter :D
 
Cool!!! That is a very nice model! Excellent

What spec panels are you using, how much are you losing due to the covering, can you get a better cover material?

Can you get a lighter panel?

Micropilot was developed by a guy , my dad knows him well.

fold out more panels the higher you get? what are your goal in this project?

Tell us more!

mikebike
 
Great work on the solar uav!!! Guys like you give me great hope and inspiration. Imagine now what could be done with more efficient solar panels. I wish thin film solar was more powerful, it would be awesome just to integrate the cells as part of the structure of the wing itself. You would probably have some great weight savings as well.

grindz145 said:
That, is so badass:) /has nothing to do with ebikes , awsome. I still want to do a quadcopter :D

There used to be a link link and img of a maned electric quadracopter on here somewhere. I think I even posted it, but it disappeared and no matter how much I troll the interwebz for it it is nowhere to be seen. But I still have it in my rusty steel trap of a mind. If I'm ever not living hand to mouth I'm going to have to give it a try. Hmmm, how many kwh of nanotech would it take to powers 4 joby motors in ducts? More than I'm worth to be sure.
 
realy cool project!!!

Could you paint in silver or white the surrounding border ( balsa) of the solar panel to maximize the solar ray to the solar panel? I see a little shadow that cove rlike 5-10% surface so it would help a bit as well

Doc
 
HI Ludo91
have you published any detailed plans on your build?
of interest for me is clear material over cells that you used,
and those problems you had getting cells and batteries to work together.
 
Yep! my nad my friend want to realease all the plans about the plane, but since we are enrolled in a damn hard college we are seriously struggling with time, but we consider our projcet ope source and as soon as we get some time to do this we`ll make a .zip file with everything in it ;)

Film is oracover (or oralite? i dont remember, will check in the orders` mail) lite, for indoor use, wich mean thermal shrinking but not adhesive, beacuse the glue on the inside of the film in out first attemp got yellowish after less that one hour in direct sun.....

having the battery work with the panels is a damn hard issue, basically you wnat a motor and a prob that matched 2gehter would work by themselves at the MPP of the cells (sound weird but we say this basing on several hours of testing with a lot of sensors) and then use a switching dc dc converter in voltage mode to increase the voltage of the whole system, relying on the battery, in order to get more power.

Basically our panels give their best at about 5.5 volts under load, with them still doing a great part of the work with the voltage raised up to 6.something volts by the dc dc converter... so having the battery stepping in to get a bit more extra power from the motor doesnt spoil the soalr nature of our toy (esc is always full chat, we change gas setpoint by changing the power rail voltage).

cheers!!! :D
 
What a project! More detailed info please.

Ludo91 said:
The panels under the trasparent oracover indoor give us 25 watts on a great sunny day, barely enough to fly,
So how much power is needed to keep it in the air? At what speed and altitude? Assuming a non-windy day of course.
How much does it weigh?
 
it is 1.6 kg rady to fly, it stays in the air with 25 watts when flying straight and perfectly flat, average consumption on a flight is about 30W, +/- 1.5W (yeah we have crappy current sensors).

We keept it at about 80 yard height

Now the plane is in a box beacuse italy is northen enough on the planet to make the october sun almost useless for panels under a plastic film (it reflect most of the light if it is not perpendicular) and also we really need to upgrade the autopilot to ardupilot mega, in order to have the barometric sensor (way better height control) and the Derivative term in the PID, so right now we are looking for a sponsor :wink:

I want so bad the release the .zip with all the info in it!!!
 
Thanks for the detailed info. What is the typical air speed at 80 yard altitude?

Best of luck on finding a sponsor and keep up with the good, interesting work.
 
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