Hello
I am an engineering student and for my final year project I am looking to develop a solar powered drone. The aim is for the drone to charge a small battery/capacitor using an attached solar panel whilst on the ground. Once it detects it has enough charge it will fly to the pre-set location, land and charge up again for the next flight.
I am thinking of using an APM 2.6 or Pixhawk for the project..
How feasible would this be?
Replies
What do people think of using a supercapacitor rather than a battery for storage? Energy density is lower but power density is higher. Since I am not too concerned about having a short flight time (enough to travel a few meters would be fine) it looks like it may be a possible solution. Also, charging capacitors is easier than charging LiPo's.
The only reason you should be thinking about super capacitors over a small lipo is if you cannot find a small enough lipo with the power density you need to fly... and that is unlikely.
If you wanted to build a true hopper simular to a grass hopper insect (rather than a multirotor) that can build up energy over a matter of just a few seconds and then propell the craft just a few metre, and then repeat... then a super capacitor is definately an advantage.... but otherwise just stick to a high power density lipo.
Remember - Lipos are readily available in sizes right down to an once in weight with a burst rating up to 130C.
Yes - charging a super capacitor is more involved primarily due to insanely low internal resistance.
No idea where you would source one but I tried this one a couple of years ago. Yup, its capacitance is unbelievably enormous and the thing is dirt cheap but it leaked like crazy. I don't remember much (I only played with it for a short while) but I must have been charging it to 2.5V (the voltage quoted) and I could see the voltage dropping measurably in front of my eyes, felt a bit like inflating a balloon with a small hole in it. I 'm guessing there's many more to choose from out there but bear in mind that this is something you might want to check.
Any capacitor is going to have a self discharge rate. They're pretty useless for most applications, which is why you never hear about them except every few years when someone hypes them like they're a new idea.
I've been looking into this for the last few months to put solar panels on a plane. This bloke Alex has shown its vastly improved his flight times and that was with 15% efficiency panels, he's now moving to 19% and I've found a company that will hopefully sell me their panels which are 21% at a DIY price (I'll post if they can sell to DIYers).
http://www.rangevideo.com/forum/showthread.php?2547-The-QueenBee-an...
He uses the genasun mppt, which is too heavy for your application, the lightest MPPT is from sparkfun.
Good luck with it!! Let us know how you go throughout the year.
Thanks for the info! I will have a read through that thread.
Hi... interesting project but it may take days to charge, not hours. There are numerous things I can type here but if you look up Insolation (not to be confused with insulation) on Wikipedia you can see how latitude and angle of the solar panel will diminish your power available. Angle is the key thing since sunrise is almost useless and noon is the only time you will get valuable power. Your solar panel will have to be too big to be of value. Here's a twist though that may be worth playing with... how about design two or more "base stations" that have larger solar arrays and are high speed charging stations for the quadcopter. You would have to design a system that could have the quad land accurately enough to be charged and the quad could then fly back and forth between each base station. The distance is limited by where you "fuel up", like an electric car going from charging station to charging station (or to back of a pick-up truck using "follow me"). The complexity is having a drone land automatically and accurately enough to be charged using electrical contacts. This may be too expensive or complex. It might be interesting to land on a large, homemade, inductive charging mat.
http://www.instructables.com/id/Wireless-Power-Transmission-Over-Sh...
Now, you could land on the mat, charge fairly quickly from larger batteries that were all the while being charged by larger solar panels at each base station. Of course a perfect landing onto some sort of system that allows electrical contact would be the best way to charge if it could be done autonomously.
Good luck... fun project.
Insolation will definitely be important, I will need to look into it in more detail.
The base station idea is interesting, it was also mentioned previously as a possible idea. My project aim is to carry the panels on board but I can investigate the base station idea further as an alternative.
Here is another idea for what it is worth, why wouldn't you consider building charging/landing stations where the quad could land to recharge and from where it would take off once fully charged ? That would save you from having to carry solar cells on board, unless this is something you are really aiming to do.
That sounds like a good idea however the aim for my project is to carry the panels on board the quadcopter. Having the panels on the ground could be a good project for using wireless charging which would remove the need to manually plug in cables.
Any idea what the power requirement would be for the flight controller, receiver, and ESC when the quad is charging? I'm not sure the small panels I listed above will be able to power them as well as providing charge to the motors.
I have found this 10W solar panel:
http://cpc.farnell.com/multicomp/mc-sp10-gcs/solar-panel-10w-17-5v-...
It is quite heavy at 1.42kg but I might be able to remove some of the frame to reduce this. I could then build the quad around this, essentially using the panel as the frame and mounting components underneath etc.
I think this method sounds more achievable. What do you guys think?
-
1
-
2
-
3
of 3 Next