Spy planes to recharge by clinging to power lines

[zik]

Interesting article in New Scientist:

http://technology.newscientist.com/article/dn13093-spy-planes-to-recharge-by-clinging-to-power-lines.html

The next time you see something flapping in the breeze on an overhead power line, squint a little harder. It may not be a plastic bag or the remnants of a party balloon, but a tiny spy plane stealing power from the line to recharge its batteries.

The idea comes from the US Air Force Research Lab (AFRL) in Dayton, Ohio, US, which wants to operate extended surveillance missions using remote-controlled planes with a wingspan of about a metre, but has been struggling to find a way to refuel to extend the plane's limited flight duration.

So the AFRL is developing an electric motor-powered micro air vehicle (MAV) that can "harvest" energy when needed by attaching itself to a power line. It could even temporarily change its shape to look more like innocuous piece of trash hanging from the cable.

[mlbco]

Now that beats the heck out of landing and slapping in a new battery pack! Just land on some "conveniently" located power lines, don't cause an explosion or fire, re-launch somehow, and fly another 60 minutes. Thank goodness our enemies have functioning, uniformly spaced power lines everywhere we want to fight a war!

At least the part about hanging like a piece of garbage in the lines should be easy. Now we'll all know where to look for used UAV parts.

Steve

[Robbie d]

why not fly past radio transmitters and absorb the power contact free. A guy was caught here doing that to power his house

[Jack Crossfire]

A bit hard to get a current going unless the vehicle can ground itself. It would have to bridge itself to a tower or lower a line to the ground. It's so rediculous, it shows how easily a single web page linked 1000 times becomes accepted fact.

[Terry S]

It was in Sheperds UAV a few months back

Terry

[Magician]

A bit hard to get a current going unless the vehicle can ground itself. It would have to bridge itself to a tower or lower a line to the ground. It's so rediculous, it shows how easily a single web page linked 1000 times becomes accepted fact.

Jack,

Try to keep an open mind and don't immediately assume that the people doing the research are not intelligent. You have come to the simple assumption that you need a closed path to generate a current from a source (like a plug in an outlet). The phase 1 effort demonstrated the ability to recharge a battery from a 7kV power line using electromagnetic induction. Thus, no direct connection is required, just very close proximity. Apparently this is the way rechargeable electric toothbrushes work. Learn something new every day!

Regards,
Chris

[Unterhausen]

we have one of those toothbrushes. It's obvious that there can be inductive coupling, somewhat like that in a transformer. Pretty interesting idea.

[dmgoedde]

Before anyone flames my idea, realize that this is brainstorming.

Imagine... a UAV that flies really close to a power line and draws power from it, but does not need to actually stop and land on it. It might require a 500kV long distance transmission line to work. The wings could have coils of 30+ gauge magnet wire in them, then proper rectifying circuitry in the plane. If the plane had sufficient wing area, it may be able to collect enough power to recharge LiPos, then jet off for recon within a few km for a few hours, then return back to proximity of the electric line for recharging. The rechargin would be a simple loiter path up and down the path for the ~1 hour it takes to fully recharge the LiPos.

I don't assume that the UAV would need to have a coil clamped around the power line for the induction to work. Merely that it be near enough to the oscillating electric field to have sympathetic induction in some coils, then proper diodes and voltage control circuitry. How big of coils? What effeciency? Could a viable plane work???

Off the top of my head, I'm not clear if the geometric plane of the coil would need to be perpendicular to a line drawn normal from the coil plane to the electric line, or if the electric line and coil plane should be together. Also, would the other electric lines (the other parts of phases) kill the possible effect? Could that be overcome by flying closer to one of the wires than the others? Could a safe distance from the lines (50m?) give anough power to fly the plane (a few hundred Watts captured)? If the electric filed screw up GPS and make that navigation un-workable (but the autopilot still function) could an alternative navigation work based on sensing the distance to line via strength of the effect?

[HoverMonkey]

Sigh, gee, now neet, another military thing to spy on us...a great idea by the wrong people in the wrong place. Why does our own Government need to do extended flights over US?

Anyhow, there is likely more than enough current up there...yes just proximity works for transmitting power...isn't that how step-down transformers work? Just put the coils next to each other but one as more turns than the other...not connected just next to each other...this thing would be a fying version of that right?

[Magician]

Sigh, gee, now neet, another military thing to spy on us...a great idea by the wrong people in the wrong place. Why does our own Government need to do extended flights over US?

Hey HoverMonkey,

Who says that this is for the military to spy on you? Seems a bit paranoid, is there something you are hiding? :rolleyes: This is a basic research effort to examine the feasibility of the technology. If it works then it may be used by DOD to gather intelligence on those who mean to do us harm and this is probably overseas. However, there may be a civil application for doing visual inspections of power lines. This type of use for a civilian UAV has been mentioned in the past.

Chris

[Unterhausen]

Hey HoverMonkey,

Who says that this is for the military to spy on you? Seems a bit paranoid, is there something you are hiding?
ChrisI have nothing to hide, it's obvious I have nothing to hide, and that's what would make me mad if they were spying on me. And since it was revealed that the NSA was getting phone companies to allow illegal un-targeted wiretaps prior to 9/11, they probably have spied on all of us. And the military was at least attempting to expand their domestic surveillance beyond what makes sense to insure the safety of military installations. I don't like your insinuation at all.

[Magician]

I have nothing to hide, it's obvious I have nothing to hide, and that's what would make me mad if they were spying on me. And since it was revealed that the NSA was getting phone companies to allow illegal un-targeted wiretaps prior to 9/11, they probably have spied on all of us. And the military was at least attempting to expand their domestic surveillance beyond what makes sense to insure the safety of military installations. I don't like your insinuation at all.

Unterhausen,

Easy there. I wasn't responding to you, my response was directed to HoverMonkey as I wrote. And it was in reponse to the assertion that this new technology to recharge from power lines (BTW the topic of this thread) was to be used to spy on US citizens. And you clearly did not recognize the little emoticon that I used as a means to denote a sarcastic comment.

Let's try to stay on topic and not get politics involved, I don't really need to know your opinion on wiretapping unless it is done with a UAV since this is the UAV forum. But thanks for sharing.

Chris

[ghoti]

Well, scale this up and you have a mass transit for people just when we need it. Bill

[HoverMonkey]

Magician I PM'd you my reply directly to you about your comments to me that seemed directed at me personally.

I hope everyone also saw how I did contribute to the orig. post and by even being in this forum I am interested in UAV/MAV. I obviously was not saying I didn't want any UAV to use this sort of technology or that it wasn't a great idea. UAV have good humankind serving missions they could be built for (not used for when idle from military use).

[clolson]

A variation on the idea this thread was originally about ...

How about building a distributed network of delivery uav's. Upon landing they could fold up small enough to fit in a chimney size tube. Then they would recharged their batteries on milk and cookies.

I mean, hanging off power lines is fine if that's what you are into, but let's see some real innovation around here!

Merry Christmas,

Curt.

[kbosak]

Nothing special.
This is just a plane designed to search for unauthorised copper wire robbers and those trying to connect to power lines. Everything else is fantasy. :p

[flying-llama]

I hope the receiver and servos are well shielded from those power line electric fields.

One thought: if I thought such things were 'hanging off' of power lines and
I wanted to try to get rid of them, I would send a glitch/surge through those
lines every so often.