This is the funniest thing I saw this week. The idea that such a teensy drone could travel continental distances by hanging like a bat and recharge between runs. Sure solar gliders may keep aloft indefinitely too. But this one steals its juice!
Saying "this would be good for power line inspection drones" is true, but think bigger. Imagine if you could operate a fleet of delivery, surveillance, _whatever_ drones, with an already in place, widely distributed charging infrastructure that costs you nothing to build (but you pay for usage).
This is like in-flight refueling massively extending the operating range of jet aircraft.
You don't even need many drones for surveillance, just a few ones that deploy mini cameras using power lines both for power and communication. Cameras wouldn't need a battery to operate because they'd remain in place. No drive logic, no sensors, no motors, no batteries: much cheaper, just leave each one at regular distance and collect information remotely.
I should have probably left surveillance out because I was thinking less about panopticon style surveillance and more things like traffic patterns, crop growth, etc.
IT could have also less malicious uses, like wildfire monitoring for example. A 360 degree thermal camera hanging from a line would allow immediate warnings about the surrounding area long before some human notices.
You're only thinking of the near certainty that a ubiquitous surveillance state would lead to government corruption, mass incarceration, general anxiety, the disruption of norms, and the end of many civil liberties. Try to focus on the upside potential for a small number of investors!
I imagine that billing for the electricity usage will be the power company’s distant second concern behind the mechanical stress of hanging unauthorized devices off a cable that was not designed with this scenario in mind.
As mentioned in another comment, these cables are designed to handle orders of magnitude more stress than a drone. (Think wind storms, entire flocks of birds, blown debris, etc)
If anything, this offers utility operators a massive new revenue opportunity. Drone fleets could pay to "perch" and recharge (giving unlimited range and ubiquitous charging), all just by reusing existing infrastructure. No need for a massive new infrastructure buildout, and "nothing left to take away" design.
Big future for whoever can successfully commercialize this.
Massive? Comparing to carrying high currents around, not so sure charging drones for a few watts would even make sense for a company that runs those power lines.
Of course they could create a sophisticated billing system, invest tens of millions in branding and marketing and then end up in the red for that particular operation.
Don't be confused by the watts-to-watts comparison.
Drone fleet operators would be paying more for ubiquitous access to drone parking on (presumably inspected and pre-approved segments of) powerlines. The energy supply is almost an ancillary service, but an important one.
Just like with EV charging today, the energy cost will presumably be higher than your household bill, or similar billing schemes. "The house always wins."
It's not that simple: just because you add a safety margin on a construction element, doesn't mean you're allowed to use this safety margin.
For example if a chain has a certified Weight Limit Load of 1 T, it means it actually lifted 4 T (or 10 T if it's certified to lift people). This is because a lifting sling is tested in very controllable environment when it's new, whereas on a building site it will be subject to dynamical stress caused by winds, it will be hit, it will be used in various temperatures etc.
Now, I'm not saying you're wrong: in case of power cables there might not be such a rigidly defined safety margin in law, and experts may figure out some assumptions, like the drones not operating during wind storms, in which the safety margin is more than needed - and therefore there's some spare capacity BEFORE the the actually needed safety margin.
But are they designed to carry those loads with a drone flock. They’ll also increase the received wind load. Unlikely to cause an issue but you still have to do the math to determine the decrease to the margin of safety
The cost of the electricity provided is negligible compared to the value of providing such a readily accessible and geographically available changing network. I wouldn't be surprised if the metered cost of the electricity itself isn't even factored in to the bill when charging for the service.
As others said, I don't think the added weight of a drone would be a concern but i have no experience here.
Weight, qi chargers aren’t just an antenna they require power handling electronics. Getting the exact right DC voltage to charge a battery from two lightweight wires is just simpler internally.
I presume the current transformer is spec'd for a particular range of current/voltage. Would the drone need to assess if the line is a suitable one before (or after) connecting?
Also was a private power line used, or did the university ask the power company for permission before conducting their field tests?
The voltage of the powerline is not relevant since the charging principle is based on inductive coupling. So as long as you have a current above ~100A the harvester should work, irrespective of voltage. And high currents equal higher charging power.
To optimize charging time, the drone could perhaps analyze the magnetic fields to determine which line has the highest current to optimize charging time. But I would assume some sort of balancing is happening between the lines and phases.
The powerline used is a custom mockup with just 5V AC. But we have also landed on real powerlines. I think there's a video in the channel of the OP video.
As others have pointed out, the energy consumed would literally be “too cheap to meter.”
More realistic would be that, If fully realized, this becomes a great secondary income stream for the power line owners.
Not only do they get to monitor their own lines with self-powering drones, but they rent out access to delivery drones, traffic monitoring drones, and (yes) whatever nefarious and helpful uses people dream up. Monitoring would not have to be perfect in order for them to still make huge profits.
Seems more akin to how the railroad companies realized that could make a fortune by using their right-of-ways for communications cables.
And for monitoring: seems like an obvious solution would be to have monitoring drones that watch for usage by other drones. :)
"Electromagnetic Simulation of Split-Core Current Transformer for Medium Voltage Applications" by N. Paudel, V. Siddharth, S. Shaw and D. Raschka (2018)
Very cool, but I see one major problem with this. You need pretty large currents in these lines. They say above 100A. I'm not sure what are the usage patterns of such lines I'd be surprised if it wasn't substantially below 100A of current even on lower voltage lines.
For example the lowest voltage that is used in my country (befoeits stepped down for consumers) is 10kV. This system would need 1MW of load to be useful. So let's say the line supplies a small community of 250 houses. Each house would need to be running a load of 4kW. How reliably can we predict such usage?
So I think this is going to be limited to "perch" on large inter-City connections.
I can't imagine power companies would be ok with this. People go to jail for tapping into power lines. Energy theft from power lines is illegal.
Even if this was somehow allowed by power companies, I wonder if they would be any weight considerations if multiple drones hooked on to the same line span.
I see applications for this, but anyone operating these drones would need clearance from the power company they are tapping into.
> "I can't imagine power companies would be ok with this. People go to jail for tapping into power lines."
Presumably it's the power companies (specifically, transmission network and distribution network operators) who will be most interested in this. They're increasingly using drones for infrastructure inspection, finding faults, etc.
Funny enough my engineering capstone tried something very similar but much more stupidly complicated. Do it while flying a parabola with a winged drone. Never got the control system to work…crashed into a lot of local power lines.
Our assumed customer was power companies doing inspection.
For affordable long range assassination operations. Make it in clear matte plastic, quiet, low flying, add some obstacle avoidance and facial recognition perhaps. Quite a nasty package under 1500 dollars I bet. Could even be ultra small w poison darts too.
Target may be able to duck in time and you'd only get one attack per drone.
Maybe a gyrojet explosive tip munition with poison coating for the shrapnel, where the firing drone could time the tip detonation by tracking the projectile in real time after launch. That would be light enough to provide several shots or for multiple targets. With infrared target the jugular. Highly inconvenient to defend against with armor and the projectile will be incoming fast enough such that there's no opportunity to evade, assuming it can get in range quietly.
There's a huge market for this. From nation states to divorcing couples
Pretty cool, though my take is that if it's recharging just from induction it's essentially stealing the electricity... I suppose if the owners of the lines want to have autonomous drones monitor their status, that's not stealing, but if you wanted to release some little flying vampire drones of your own which could run indefinitely that way, someone might be less amused.
It's odd that people in the comments assume use without permission and stealing.
You wouldn't attempt any of this without permission, regulatory approval and insurance, unless you wanted to be sued, prosecuted and go broke if something went wrong. How do people think the real world operates exactly?
I dont know. There is definitely a flow of energy between the power line and the drone. But there is no closed circuit between them so there is no current flowing. I imagine there is a (slightly, almost not measureable) raised current in the powerline due to a lower resistance due to the parasitic voltage drop and phase shifting cause by the inductive load. So technically no current between the drone and the powerline. Although there is energy transfer.
But there are probably lots of people here that understand the laws of electromagnetism a lot better than me.
300A of current is going through the wire, at high voltage - that's the transmission current. Drone is not charging directly from that, it lacks a ground / other phase connection to directly tap into the wire voltage (also, it lacks a... power substation and a bunch of other stuff to step down and convert the high-voltage AC from the line to low-voltage DC for the battery). Instead it uses an induction charger that "leeches" off of the magnetic field of the wire. If the wire current is higher, the magnetic field is stronger, so it can pull more power than the currently possible 50W.
driving drunk is illegal as shit too, but you can't be naive enough to believe that's enough to stop people from doing that. If you had a drone and wanted to see if this worked, you'd just drive 50 miles from your house and just... try it out. The US isn't yet covered with surveillance cameras like the UK.
Bro, "it's better to ask forgiveness than permission" is a pretty common saying in business circles. A lot of enormous businesses, such as Uber or AirBnB, were founded completely on operating without permission, regulatory approval, or insurance, until those things were absolutely forced upon them, and even then they didn't always comply with the law. It's also common that companies assume they will be sued, and go ahead anyway because they know they'll make more money than they'll be sued for. And if you do get sued... there's a good chance you can just never pay up, which I'm seeing more and more often.
The real world is certainly not your optimistic "corporations won't do anything wrong because they're afraid they'll get in trouble".
You mean like Microsoft and Apple stealing intellectual property from Xerox? Or more recently, like Cambridge Analytica?
Those are the ones that you can read about on Wikipedia. There's plenty of corporate theft happening all the time that never makes it into the public eye.
I mean bro, Boeing just murdered a whistleblower. It's not like criminality is inherently a barrier for companies.
> A passively actuated gripping mechanism grasps the powerline cable during landing after which a control circuit regulates the magnetic field inside a split-core current transformer to provide sufficient holding force as well as battery recharging.
When the grippers close they probably close the loops of a coil that wraps around the wire. So it's harvesting the ever changing magnetic field that arises from AC current, independent of voltage. You can still get some power from coils that aren't wrapped around the wire but are still parallel. I think that's how wireless phone chargers work.
You can also take power using a capacitor instead of an inductor, from the changing voltage (not current) in an AC line. Like when you hold a florescent tube vertical under a hi-power line, and it lights up.
This would vaporize the drone, the wire, and anyone or anything nearby, sending flaming battery and electronics shrapnel in many directions. High tension does not mess around.
There's nothing gentle about 38kV. You're not going to lower down a line and bleed off some charge. Once there's a viable path to ground, current will flow all over whatever is making that path, including the very air around it. The entire drone, wire, and the air it is inside of will turn into vaporized plasma as if hit by a bolt of lightning. And 38kV is low voltage in the high-tension world.
Creating current flows from a field is what induction is, so if you're imagining that you could just generate electricity from a field, well, that's what they're already doing. It doesn't take lowering a probe. You can just use an inductor.
That is exactly opposite of what would keep the drone safe. In a power transmission network the earth is a conductive path. Touching a phase and touching earth allows the grid to push as much power through you as your impedance and grpund contact will allow.
If that can be measured, I would be pretty surprised.
I would project that the drain from all possible drone charging is orders of magnitude less than the e.g. coronal loss or the static radiation that blasts my ham radio.
Any legal action would need to be able to document that loss, one would think.
But you agree the loss exists, right? It's simply difficult to detect from some aggregate noisy flow at a centralized ___location, because the system was never designed to make that easily measurable.
The amount could be estimated by looking at how much flying the drones do between charges, or by suing for access to charging/position telemetry of the units.
If the drones could meter their own consumption from the line using a utility-approved meter, anyone with a drone with said meter should be able to just tap onto lines at will and get a bill at the end of the month.
Not sure how that plays out in terms of the weight/packaging of the drone but seems feasible for at least larger drones.
I would argue that it is less than an order of magnitude smaller than the coronal discharge or other losses.
I suspect we are talking about 24 watts as compared to eg 1000 megawatt 500kv line. This is seven orders of magnitude difference. Totally lost in the noise.
Effective immediately, all airspace below 500 feet near powerlines is now classified as Class M airspace (for money). If your registered drone is detected nearby, you’ll be charged per second.
> smaller than the coronal discharge [...] lost in the noise
This is again technically plausible but ethically irrelevant.
It's like the fallacy in: "It's OK for people to steal goods from that store, because the parent-company is very big and one theft won't even show up on their monthly financials and they've got spoilage and breakage too."
> I suspect we are talking about 24 watts
The video demonstration shows 50 watts of input.
Napkin-math: Suppose one drone uses 1000 (battery) watts flying around, and does so for 4 hours each day for a month. (Made possible by an improved version of this research that charges at 200w.) That's 4 kWH. The electrical price is $0.20/kWh.
That means siphoning $24/month for one drone. That's not a casual "keep the extra penny", that's a Netflix Premium subscription.
An alternative view, power companies point the finger at drones for outages or fires. Look the other way when people are stealing pennies. When the billion dollar bill comes in, hand it off to the police. Let them identify the operator, and put them on the hook for damages.
right now the loss does not exist. Its a cool experiment. If this was a big thing the drone fleet operators would simply get some kind of legal agreement with the transmission operator. But overall we are talking about really small amounts of energy.
> we are talking about really small amounts of energy
Napkin-math time: I see 4 motors, searching the model-number suggests each has a max draw of ~380 watts, so let's assume it averages 1000 watts in operation, for 6 hours a day, with a local cost of electricity at $0.20 per kilowatt-hour, and this continues for one month.
That's bad napkin math. Per the video, it is charging at 50W. At worst, it would be charging 24hr/day, so 50Wx24h is 1.2kWh per day. Using your 20¢ rate, that's $0.24 per day or 7.20/month. That's the upper bound, assuming it only charges and does no work.
> That's bad napkin math. Per the video, it is charging at 50W.
I previously pointed that out to someone in another comment, however I did not use 50 because the video-presentation continues with:
> The current in the power-line was approximately 300 amperes [...] a higher power-line current would result in a proportionally higher charging power. As future iterations of this system become more efficient, the ratio of time spent flying and time spent charging will significantly increase.
The point remains that once you reframe the electrical situation in financial terms, you will realize it is not just gleaning discarded ergs, and is instead significant enough to raise questions of theft and justice.
This could become a major power draw over decades. It's probably time to figure out a protocol. E.g. a cheap light small low power meter on the drone that can post the transaction to the electric company while in flight, signals to designate power lines as in or out of the system and their current price, etc. Solar roof owners could compete with the utilities. There are unicorns hiding in this forest.
The vampires will be the charging drones that aren't associated with a transaction. So it's about as enforceable as a requirement that drones have accurate identifier transponders.
If I was the power distribution owner I would not trust the drone meters. Probably would need some type of load profiling on the distribution side, then all the drone has to do is authenticate a valid customer id for billing.
> If I was the power distribution owner I would not trust the drone meters.
Understandable.
> then all the drone has to do is authenticate a valid customer id for billing
I mean you can ask for anything, but how do you police it? If the drone is by a recognisable entity doing legitimate things sure you can fine them if they don’t comply. But what do you do with literal fly-by-night operators?
How so?
There are 120,000 miles of transmission lines in the USA. Not all of that is overhead high voltage, but the system is still vast. Where do you put the net?
The problem has three prongs:
Detection: there is so much line, and much of it is away from regular eyes. Intermittent-moving threat: Imagine you get a report about a drone perching on your wires. You schedule and dispatch a team to deal with it. Most likely by the time they arrive on site the drone is gone. They are playing a catchup game with moving threats. Action: okay, you got a drone in sight. Either because it didn’t move away, or because you got lucky. What do you do? Mind you the lines are really high and poking things near them can be hazardous if not done correctly. So it is not just any Harry and Dick who can deal with the drone, you need someone trained and with the right equipment.
On the other hand, hung lines have a tendency to fall down, get tangled in trees, and start forest fires, so the cost of above ground lines is also high...
Burying those lines is not practical. Inspecting and repairing them is. The problem is significant deferred maintenance. Buried lines cost much more to maintain, in addition to installation costs even where they are feasible. It's better to make sure (1) the towers don't fall down (2) into a forest ready to ignite. That can be done, but we have to pay.
See this is the thing: people complain about the little bit of power being eaten up by drones. But if power companies really cared, they’d bury their powerlines.
This is a classic prisoner’s dilemma, and you’re advocating for both sides to hit “betray”.
Perhaps if enough drones did this, they would indeed bury the lines. But that would be strictly worse than a world in which they didn’t bury them, and drones don’t steal electricity regardless.
Theft, yes, how serious? Not very. Basically a rounding error for the power company. They likely see higher loses from things like fence lines installed near power lines.
In which case the earth itself can steal the power, in addition to making your electric bill 500 times higher from the capital cost required to bury millions of miles of transmission network.
I don't think you know how infinitesimal the amount of power would be. Assuming a Mavic Mini traveling at its maximum speed of 29 miles per hour, it could cross the continental united states in 99 hours for 36 cents worth of electricity.
Yeah, it’s easier to use lab test data from Mavic Mini 3 specs: 51 minutes flight time at 21kph [0]. The battery capacity is 28.4Wh [1]. So, 18.4/(21*51/60) = 1.6 Wh/km. Assuming US is 2800 miles (4500 km) wide, we get 7.2 kWh of energy under ideal conditions, without accounting for charging efficiency and the impact of the charging system weight on flight time.
Edit: 21kph is the optimal speed for max flight time but not for the best energy efficiency per km. Most efficient speed is somewhere between that and the top speed. But this is the right order of magnitude at least.
More likely it’ll be utility companies that want to do remote and autonomous inspection of the transmission network. It’s already a big business, but if you can run the drone the entire length of the line without relocating the base as frequently, or have no base at all and transmit data over 5G? Big wins.
Right. Drones for power line inspection are common. Far easier than inspections involving bucket trucks, helicopters, or even people on the ground with binoculars. This will simplify that process. Especially for lines through rugged country, where following the line is difficult. Start the drone where the power line crosses a road, and then drive to another road crossing for pickup.
Warning lights for aircraft which clamp onto power lines have been available for many years.[1]
Powerline inspection and maintenance are the primary use cases for this technology. And at least this particular system is in the early spinout process via https://www.ongrid.tech/
I imagine something like a weaponized version of this, loitering semi autonomous drone swarms fully charged / ready to deploy hanging off wires... a bit like the US spider munition or just smart landmines.
And we had loitering missiles for a long while too. They are a valid use case.
> You just launch them when you have a target.
That is the magic. You can launch a loitering munition when you don’t yet have a target but suspect there might be one. This is very often the case with surface to air missile systems. If they radiate you can use that as a guiding signal to hit them, so most of the time they don’t. You launch the loitering munition which either baits them into radiating or you use something else as bait. Either way you get them to radiate and then the loitering munition already in the air homes in on that signal and destroys the radar, or if it is smarter the personel.
The reason you want these to be in the air before they radiate is to shorten the reaction time. That way you can capitalise even on short burst of activity.
In the end you either destroyed the SAM or supressed them by scarring them into not to radiate.
If this sounds scifi to you, these are weapons from the 80s. Already old news.
"Terrorists" could just bolt a buzzsaw to a drone, drive a mile away from the power line in a truck with a few barrels of extra diesel and a generator and cut away until they get bored of it.
But I see an opportunity for the security theater industry there...
Those are different kind of drones. To successfully enhance a refinery, it takes a smallish plane with a pot of explosives, not a tiny grenade-dropper or fpv.
Semi-seriously: Yet another item on the list of ideas I totally came up with on my own, honest, I just never did the hard work to make it real.
(I know, I know, my ideas count for nothing when I don't turn them into reality. Actually making hardware means solving a lot more problems than my imagination provides, and who likes facing those surprises in side-projects?)
Yeah, this idea was pretty obvious -- both at LANL and JPL I worked in labs that were doing perching drones and we talked about landing on powerlines and charging inductively. The LANL work was 2013 and the JPL work was 2018. I think most "good ideas" are going to be thought of by thousands of people before they become a useful reality. Ideas per se really are pretty worthless and patents are only useful as a means of proxy warfare between large corporations, I'm afraid.
Ever since I was a kid I've wanted to build a hanging chair something that latches onto powerlines and travels along them :-)
Also reminds me of how I actually built a burrito delivery drone for fun that lowered a burrito on a winch a couple of years before the "tacocopter" story started doing the rounds on the news (early 2010s). It's interesting that drone delivery never made it beyond rural pharmaceuticals.
I believe you can get patents without a physical model?
I wouldn't have bothered with a patent for something like this though. Probably is money in it now I think about it, but patents are just not the kind of thing I think much about.
Can't wait for the failure mode where they sit over HVDC lines, fail because there's no alternating magnetic field, and then fall on them and hobble the infrastructure.
The gripper has several modes. There's a mode for charging the battery and providing holding force given AC powerline current, a mode for just holding the drone without charging given AC powerline current (if battery is full), and another mode where a small current (about 1W power) is taken from the battery and used to provide holding force in the case where there is no powerline current. Additionally, the gripper can be designed to fail open or fail closed, whichever is deemed appriate for the end-user.
Such drones are not practical in the war zone, because this introduces dependency on wires and electricity. In our air space it's no helpful. In enemy air space it's vulnerable to enemy action.
It's going to be a very costly operation to go retrieve one of those once it's "gripper" ultimately fails. That's hoping it fails closed instead of failing open. Getting these parked in the face of upcoming weather is not going to be particularly fun, either.
Given that you need a solid alternate ___location anyways, why not just go there instead? Then we can build safe single function autonomous ground charging stations that a human being can just walk up to and service on foot.
The application is for drones doing work in the field and needed to recharge on that basis, it's actually a very good solution for coverage of a large, possible remote, area. The alternative is a large number of charging locations which is very expensive.
There's no need for alternate charging or parking in weather. Besides merely going into a hibernating state with a radio beacon and light in emergencies, recovery could be via a vehicle positioned in an optimal ___location relative to the drones where they can all converge and be collected. In the case of charging limitations you could execute more than one convergence ___location.
Also the drones could be used to remove failed drones stuck on lines.
I'm suggesting that hanging random amounts of weight off of power lines is probably not a great engineering plan, less so if the wind or heat or load picks up significantly. My concern isn't for the drones it's for the actual power infrastructure.
Are the drones designed for inspection or for heavy lifting and applying mechanical leverage against other objects? Are you so sure they're going to be able to do both?
It's trying to solve two problems at once, and while the solutions individually may be clever, combined they seem like a total waste and fraught with complications.
Really, you're overly negative. Those lines aren't light to begin with, wind and other issues you mention are just basic design considerations. And the important point is there are no good alternatives.
Really, my disposition has no bearing on the facts. They are designed to handle wind but I doubt those design parameters included random weights attached at random points between spans. The lines also change shape based on temperature.
If the clamp abrades the line under high wind conditions then you are weakening and possibly breaking the line. If the hardware that mounts the line to the tower can't handle the additional loading then you risk breaking it and dropping a live line on the ground.
No good alternatives? That's exceptionally unimaginative. The lines are strung up with towers. You could just put a station, on the ground, right at the base of the tower, where it would be much easier to directly connect it to the power lines in a safe and permanent way.
For the light drone they used in the paper they had a 5 to 10% cycle. It has no detection equipment on it. They're ultimately going to need a much heavier drone to actually do inspections. Which, if you're going to go the autonomous route, ground based charging becomes much more justifiable in terms of fixed cost.
Aside from that, they already have ground controlled attached cable "walking" drones in use by several providers and manufactured by several companies. Similarly to human inspectors you wouldn't deploy them on a windy day either and can have professionals ready and on scene in case any problems do happen.
Anyways.. the point of this paper is they've worked out the landing and release technology and can credibly claim continuous operation although with a very little flight time in between recharges. Which is great, but as an application to the inspection problem, I still maintain it's too clever by half.
This has applications, likely with custom drone only infrastructure, in which case you could do direct attachment and really speed up the charge time to something useful, but my strong guess is certainly not for autonomous inspections.
I mean… who’s to say you aren’t operating these for nefarious purposes and the last thing you want to do is have them go back to a central ___location? Or if they are part of a defensive perimeter, or a long haul operation, where centralized service is problematic? These could be used for power line infrastructure observation and possibly even repairs at some point.
