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UAV Hoisted Tower Powered By Laser Over Fiberoptic
carstene writes "LaserMotive, winners of the 2009 NASA power beaming contest, has a new invention, a virtual comm or surveillance tower. It's a quadcotper that can run indefinitely, powered by laser beam over a fiber optic cable. This allows the "tower" to reach great heights and avoids most laser safety issues."
So, it's like one of those plane-on-a-string things that fly in circles? BuzzzzzzZZZzzzzzZZZzzzzzZZZzzz.
take electric power from a cable, inefficiently convert to light, run it through a cable, inefficiently convert it to electricity, then use what little is left!!
Why not just use the electricity and a copper cable???
...is that you have to retract the UAV during a storm. While it's retracted, you've lost the UAV's capability. So, I can see these deployed in emergencies when you need comms fast. But eventually you'll want to build a tower.
Finding God in a Dog
Atlanteans had this tech back in the 10,000 BCs except they didn't bother with a tether, they just beamed their maser (that's Microwave amplified...) energy through crystals seated on top of large pyramidal buildings. We're so 20,000 years ago.
Hovering sharks with frickin' laser beams?
Tethered ground-powered rotor-lift platforms date back to WWII. Israeli Aircraft Industries has one in their product line today. They're usually installed on the back of a vehicle, so you can pop up the camera unit and take a look over the next hill. Early versions had no guidance and just used enough power to pull the tether taut. Modern ones fly actively, so they can be used to peek around buildings.
Using a fiber optic to transmit power is rather inefficient. Probably 70% - 80% of the power is lost that way.
Why not just use a balloon? The only advantage I can see this having is less movement due to wind, but designing a properly shaped balloon should easily defeat that, and more importantly a balloon would be much quieter at low altitudes, use much less power, and stay aloft even if the power is cut. Seems like a case of a hammer looking for a nail.
The fiber optic cable is the main advantage here. It gives you better data transmission to the airborne antennae. But in order to really facilitate that, the system probably needs better stability in wind than a balloon. (This is admittedly a SWAG.)
Finding God in a Dog
What's the point of a heavier-than-air, tethered, actively powered, stationary platform?
Seems to me that a good copper wire and high voltage AC would be far more efficient and at a high enough voltage the wires could be very thin and still deliver loads of power..
Instead of converting electricity to light and back again, just keep it electric.
One of the advantages of this design over a lightweight copper power feed is that DATA is bidirectional over the same optic cable. Transmitting the surveillance data back to the ground is much more secure and at higher rates than through thin copper or over some RF transmitter on the copter. That is, this can be stealthier.
Help! Help! I'm being repressed!
I couldn't seem to find any references as to the size of the payload this device can hoist up to 600 feet. I mean it's cute and everything but if it can't fly when you add a camera, exactly what kind of "surveillance" do you plan on doing with it?
Seven puppies were harmed during the making of this post.
Because a balloon, at best, is filled with Hydrogen, and doesn't carry a lot of weight. This is for surveillance, possibly covert. Flying a giant balloon from a ground station in a forest outside a Colombian drug lord hideout wouldn't be the wisest move.
A copter on the other hand can be small, nearly silent, and left heavier equipment without nearly the visual footprint. It can also be rapidly deployed and returned for "quick looks". It can be taken to an exact height and location, not blowing around, and would not need tanks of gas brought around with it... A laser hooked up to a generator would eventually be safer and more portable and reusable in a battle or disaster.
It would also be much easier to remote control, turn the camera. What use is a balloon at say, a nuclear disaster zone like Japan, if the camera isn't stable enough to actually zoom in remotely without making the operator throw up?
I8-D
I was actually hoping that wireless transmission of power didn't mean there was some sort of big cable connecting the transmission endpoints. But I see there are just no wires in the big "wire" that connects the drone to the ground.
fiber optic cables won't attract lightning?
(unless they are wet I suppose)
every day http://en.wikipedia.org/wiki/Special:Random
They clearly only need one fiber to deliver the energy, but would need two copper conductors. I wonder if there's a way to deliver the energy over one copper wire.
Nullius in verba
create a single molecule the size of your balloon, last stage of assembly, remove the gas molecules within.
(kinda like the pupeteer space ships, a single molecule of very large proportions.)
so long as it's strong enough to withstand the crushing force of the vacuum
Hell, use that really strong material known as aerogel.. either way, have the gap space be a vacuum
it would lift a hell of a lot more than hydrogen....
every day http://en.wikipedia.org/wiki/Special:Random
The critical factor behind InvisiTower is laser power beaming, which involves the wireless delivery of electrical power over long distances via laser beam ... In this case, laser light is beamed through the fiber optic cable and converted into electricity at the aerial platform.
Um. The phrase "wireless" must mean something completely new.
It must have been something you assimilated. . . .
Does one really save weight by transmitting laser power through an optical fiber versus using a lightweight electrical cable (maybe silver?) at a relatively high voltage? Even after the losses involved with converting the light back to electricity at the copter (probably about 50%)?
Serious question, is the power density of optical fiber really that high?
I've seen this technique used for sensors (http://spectrum.ieee.org/energy/the-smarter-grid/electricity-over-glass), wouldn't have thought it would work well for something like this.
We're wanted men. I have the death sentence in 12 systems!
maybe if the fiberoptic is a good insulator, it will be less likely to try to carry current to the ground and blow the helicopter and ground station to bits. This would make it safer in areas where there are power lines. It also might make it safer when the weather is not so nice.
How are low-flying aircraft (always likely in emergency situations) warned away from the tether?
New mod option wanted: -1 DrunkenRambling