Tiny, Hackable Quadcopter Drone Launches Pre-Orders
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Aerostat meant anything that hung in the air. This was an easy trick to pull off
nowadays. Nanotech materials were stronger. Computers were infinitesimal. Power
supplies were much more potent. It was almost difficult not to build things
that were lighter than air. . . .
Given that it was so easy to make things that would float in air, it was not
much of a stretch to add an air turbine. This was nothing more than a small
propeller, or series of them, mounted in a tubular foramen wrought through
the body of the aerostat, drawing in air at one end and forcing it out the other
to generate thrust. A device built with several thrusters pointed along
different axes could remain in one position, or indeed navigate through space.
Each aerostat in the dog pod grid was a mirror-surfaced, aerodynamic teardrop
just wide enough, at its widest part, to have contained a pingpong ball. These
pods were programmed to hang in space in a hexagonal grid pattern, about ten
centimeters apart near the ground (close enough to stop a dog but not a cat,
hence "dog pods") and spaced wider as they got higher. In this fashion a hemi-
spherical dome was limned around the sacrosanct airspace of the New Atlantis
Clave. When wind gusted, the pods all swung into it like weathervanes, and the
grid deformed for a bit as the pods were shoved around; but all of them even-
tually worked their way back into place, swimming upstream like minnows, pro-
pelling the air turbines. The 'bines made a thin hissing noise, like a razor
blade cutting air, that, when multiplied by the number of pods within earshot,
engendered a not altogether cheerful ambience. Enough wrestling with the wind,
and a pod's battery would run down. Then it would swim over and nuzzle its
neighbor. The two would mate in midair, like dragonflies, and the weaker would
take power from the stronger. The system included larger aerostats called nurse
drones that would cruise around dumping large amounts of power into randomly
selected pods all over the grid, which would then distribute it to their neigh-
bors. If a pod thought it was having mechanical trouble, it would send out a
message, and a fresh pod would fly out from the Royal Security installation be-
neath Source Victoria and relieve it so that it could fly home to be decompiled.
--Neal Stephenson, The Diamond Age> As a result, hazardous elements such as the assemblers, the bacteria, and the nanobots were blown into the desert, evolving and eventually forming autonomous swarms. These swarms appear to be solar-powered and self-sufficient, reproducing and evolving rapidly. The swarms exhibit predatory behavior, attacking and killing animals in the wild, using code that Jack himself worked on. Most alarmingly, the swarms seem to possess rudimentary intelligence, the ability to quickly learn and to innovate. The swarms tend to wander around the fab plant during the day but quickly leave when strong winds blow or night falls.
The problem is the battery recharge time is way more than the flight time. You need better than 1:1 for this to work.
Beamed power (sufficient to power something's lift) is going to have a scary energy density.
Maybe mechanical energy storage is the way to go; use counter-rotating flywheels that you can spin up rapidly, and then bleed off rotational power directly into the fans. Use a battery for powering control circuitry only.
Power for an efficient sailplane is alright for an afternoon... but only barely have we achieved the 48-hour golden timespan with extreme size, expensive materials, good weather, and working the batteries to within an inch of their lives.
Power for a hyperblimp, which is probably the closest to what Stephenson described (but 1-2 orders of magnitude larger), is easy to provide with solar. Expect them reasonably soon in military applications.
There is experimental-but-also-just-barely-workable laser propulsion, and also what I like to call a 'Flying Pole' where a wire-tethered quadrotor sits in one place 100 meters up for a vantage point, indefinitely, with significant practical payload (this is used experimentally by various militaries).
Lastly, there is the holy grail, autonomous swarm launch, landing, and refueling, which allows a large number of quadrotors to blanket an area of several kilometers around with close-in distributed surveillance. With the right code and minimal hardware, and importantly a large enough swarm to justify infrastructure, this is highly practical, the engineering just has to be done. I have my doubts that this will be reliable for a while with small fixed wing drones - the wind and approach makes it a much harder problem than VTOL craft.
In case you're interested, UAV construction is now a large sector of the RC aeromodelling hobby. I've tried to catalog developments on my wiki, http://dronepedia.com , but it's a firehose of information out there. If you want to dip your toes in, check out a day's discussion on http://diydrones.com
It's gonna be a lot easier to fry something traveling slower than the speed of sound from a few hundred feet away than something travelling at orbital velocities miles away.
Too bad about all the dead birds though.
You are exactly right. Except of course that the current 'relative restraint' is in the eye of the beholder, and it probably doesn't seem like 'relative restraint' to those living in certain areas of Pakistan.
But yeah, soon enough that'll be all of us. We're in for a world of horror. If we were wise, we'd be establishing the idea that military drones are to be prohibited by international treaty and considered a war crime, not normalizing them.
Having said that, I am actually not very pessimistic about drones. I think that they are similar to cars, which enable a quick get away for the perpetrators of a crime, but are in fact more dangerous in accidents than as means of a crime. ( And similar, if there are thousands of pizza delivery drones then some of them will fall out of the sky by pure statistics.)
If it wasn't useful for combat, nobody would use it, right? You only need international law to try and prevent things that _are_ useful in military objectives, but are so dangerous to humanity that we wish to prevent their use.
You might be able to juice it up in midair, but the field would have to be somehow focused on the quad, otherwise you'll never get the required power density.
Apologies for the self-indulgent links -- I wrote the articles, so they were easy for me to locate. ;-)
[1] http://www.hizook.com/blog/2012/04/17/wireless-power-transfe...
[2] http://www.hizook.com/blog/2010/07/20/gliding-uav-perches-po...
The side-view picture in your write up looks almost like a helicopter. Look at a different angle though: http://www.airplanesandrockets.com/airplanes/images/models-i...
From a practical perspective, wireless power transfer (of pretty much every form) can have major drawbacks... but they're "rearranged" in the system to make 'em palatable. For example, the system as a whole may be incredibly lossy -- but that's predominantly at the ground station where you have ample access to power. Often, you're willing to accept 10% conversion efficiency when 100% of the converted power is useful to the target (think of RFID tags). In other cases, the benefits of near-field (short-range) inductive charging are (1) lack of wires and (2) more robust physical design (check out Sphero). TL;DR: there are circumstances where all these things make sense, but it's very application and system specific.
As for your take on acronyms... UAV => Unmanned Aerial Vehicle. Brown's contraption flew (albeit attached to guide wires for stability) without an occupant. What would you call it?
You can make a ping-pong ball hover in an upward column of air, but I wouldn't call the ping-pong ball a UAV. It's just semantics, but I think the term implies a certain level of autonomy. Another example, there are many radio controlled aircraft in the hobby world that I would not call UAVs. One could take the same r/c vehicle, integrate an autopilot, and then UAV might be a more appropriate term for it.
In my view, anything with Return To Home level autopilot and above could reasonably be considered a UAV. This generally requires a 6-9DOF IMU, an altimeter, and a GPS receiver.
It promises better hardware (Cortex-A9 SoC, 1.0-1.5GHz CPU, 1GB RAM, SD card, 2.4GHz/5GHz Wi-Fi and Bluetooth), at a third of the price (MSRP: $49).
But again, it's not real (yet?) - whereas the pre-order of the Crazyflie Nano has at least already started. And they seem to have a firm shipping date.
I know this would increase costs a LOT but it would be awesome if it could be redesigned to use smaller chips and put more of the weight to the battery.
On that can anyone explain to me why they positioned the batter on the top of the device? Wouldn't it be better balanced to have placed it below the body? Not that stability looked like an issue just seems like an odd design choice.
That model is rather crazy across the whole spec: 16g, outdoor, max speed 10m/s, 25min flight time, steerable camera, just unbelievable.
I think I might get one and try to make some sort of induction charging / IR base-station seeking setup, like a roomba. Probably makes the most sense to put the IR beacon on the chopper and have a webcam in the base-station guide it back for charging.
It's pretty standard for any electric copter these days. It's a simple matter of energy density.
If you go on hobbyking.com and build a standard-size quad from parts, you won't get much more flight time than that. Somewhat better, sure, but not a whole lot.
This is reason #387 why we need a revolution in energy storage.
My payload capacity isn't particularly high but a GoPro sans case is only just over 90 grams, so it works fine.
I do agree that we're reliant on advancements in energy storage to push the flight time envelope, but improving even nearly twofold on 7 minutes isn't particularly difficult.
http://www.rcgroups.com/forums/showthread.php?t=1666155
Very simple chassis, Depron and some wood sticks. 1500kv motors. 5x3 props. Turnigy nano-tech battery, but with a choice of two models:
1. Either 1000 mAh weighing 79g
2. Or 1400 mAh weighing 119g.
Which battery would you choose?
At $120 and some soldering, this gives you 18 minutes flight time and >50g payload. Flymaple seems to be rather close to Crazyflie hardware-wise.
[0] http://www.walkera-parts.com/shop/m74/ATTOP-TOYS/p14245/ATTO...
[1] http://www.dfrobot.com/index.php?route=product/product&p...
Now to think up some exceptionally opsish type thing to do with them, there is data center re-con of course but I was thinking like "go sit on the bad top of rack switch and blink your LED" kinds of things.
dimidium facti qui coepit habet: sapere aude, incipe
Then, we will have a slew of companies that guarantee 'security from aerial surveillance'. I'm sure they'll make a killing.
If they aren't already working on it they need to build interfaces for mobile devices.
Also: I don't know if you've ever tried to break or cut a circuit board but it's pretty tough stuff for its weight too.
The main issue is that you don't want your board flexing on any regular basis, because that will cause the solder joints to crack.
Again, the low mass really helps.
It's a pretty popular solution among those who build small quads.