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Quadrocopters Throwing and Catching an Inverted Pendulum

Soulskill posted about a year and a half ago | from the next-up:-catching-baseballs dept.

Hardware Hacking 103

derGoldstein writes "We've seen some very impressive aerobatics performed by quadrocopters before, but this is getting ridiculous. Robohub points to the latest advancement from the Flying Machine Arena, which developed algorithms that allow quadrocopters to juggle an inverted pendulum. One of the researchers working on it said, 'We started off with some back-of-the-envelope calculations, wondering whether it would even be physically possible to throw and catch a pendulum. This told us that achieving this maneuver would really push the dynamic capabilities of the system. As it turned out, it is probably the most challenging task we've had our quadrocopters do. With significantly less than one second to measure the pendulum flight and get the catching vehicle in place, it's the combination of mathematical models with real-time trajectory generation, optimal control, and learning from previous iterations that allowed us to implement this.'"

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It (5, Funny)

JustOK (667959) | about a year and a half ago | (#42980215)

It don't mean a thing if they don't compute that swing.

Re:It (0)

Anonymous Coward | about a year and a half ago | (#42980449)

A first step would be to learn how to catch/throw an inverted pendulum with known physics, next would be adding calculation of the physics.

Video direct link (-1)

Anonymous Coward | about a year and a half ago | (#42980753)

Direct link to YouTube video [youtube.com]

science (1)

darkob (634931) | about a year and a half ago | (#42980225)

Science. Making ideas possible.

Re:science (1)

Remus Shepherd (32833) | about a year and a half ago | (#42980369)

Ideas like Skynet.

Re:science (0)

Anonymous Coward | about a year and a half ago | (#42981369)

When these things become self-aware, humanity is boned.

Re:science (3, Funny)

JeanCroix (99825) | about a year and a half ago | (#42981395)

Do you have pendulums in your house? PAK CHOOIE UNF.

Re:science (1)

siliconjunkie (413706) | about a year and a half ago | (#42982597)

I am protracted.

Re:science (1)

Anonymous Coward | about a year and a half ago | (#42981721)

What if humanity becomes self-aware first?

Re:science (1)

Rik Rohl (1399705) | about a year and a half ago | (#42986211)

The way we're going?

I'd put my money on the robots.

Re:science (2, Insightful)

Anonymous Coward | about a year and a half ago | (#42981329)

This was a triumph!
I'm making a note here:
"HUGE SUCCESS!!"

It's hard to overstate
my satisfaction.

Aperture Science:
We do what we must
because we can.

For the good of all of us.
Except the ones who are dead.

But there's no sense crying
over every mistake.
You just keep on trying
till you run out of cake.
And the science gets done.
And you make a neat gun
for the people who are
still alive.

I'm not even angry...
I'm being so sincere right now-
Even though you broke my heart,
and killed me.

And tore me to pieces.
And threw every piece into a fire.
As they burned it hurt because
I was so happy for you!

Now, these points of data
make a beautiful line.
And we're out of beta.
We're releasing on time!
So I'm GLaD I got burned-
Think of all the things we learned-
for the people who are
still alive.

Go ahead and leave me...
I think I'd prefer to stay inside...
Maybe you'll find someone else
to help you?
Maybe Black Mesa?
Find More lyrics at www.sweetslyrics.com
That was a joke Haha! Fat Chance!

Anyway this cake is great!
It's so delicious and moist!

Look at me: still talking
when there's science to do!
When I look out there,
it makes me GLaD I'm not you.

I've experiments to run.
There is research to be done.
On the people who are
still alive.
And believe me I am
still alive.
I'm doing science and I'm
still alive.
I feel fantastic and I'm
still alive.
While you're dying I'll be
still alive.
And when you're dead I will be
still alive.

Still alive.

Still alive.

Re:science (1, Troll)

Threni (635302) | about a year and a half ago | (#42982435)

There's also an Islamic version which makes a funny noise and then crashes into the nearest building!

a fancy way (-1)

Anonymous Coward | about a year and a half ago | (#42980233)

This is great, now American will be able to kill arab civilians in a fancy way

Re:a fancy way (2)

K. S. Kyosuke (729550) | about a year and a half ago | (#42980477)

This is great, now American will be able to kill arab civilians in a fancy way

What, by using a Kraut stick grenade as the inverted pendulum in question?

Re:a fancy way (0, Troll)

emho24 (2531820) | about a year and a half ago | (#42980765)

Warning, blatant hypocrisy on display!

Drones kill arabs in other countries? Hooray!

Drones flying over my head in my own country by my own government?! Succession! Civil war!!! Militias!

Re:a fancy way (1)

K. S. Kyosuke (729550) | about a year and a half ago | (#42980975)

Is it just me or have you just misspeled "secession"?

Re:a fancy way (1)

emho24 (2531820) | about a year and a half ago | (#42981023)

I was so outraged by the thought of drones used against me and not against some foreigner that my trembling rage filled fingers hit the wrong keys.

Re:a fancy way (1)

Gabrill (556503) | about a year and a half ago | (#42983945)

To be pedantic, "Succession" would be viable as a result of impeachment. Just saying.

Re:a fancy way (1)

tibit (1762298) | about a year and a half ago | (#42985665)

Yeah, troll, because quadcopters' only use is to develop military tech. Must have never heard of people studying control engineering. Ultimately, proof is in the pudding. Either you make a device that works using your control scheme, or it doesn't. Now fuck off.

Terminators (4, Funny)

ArcadeMan (2766669) | about a year and a half ago | (#42980269)

It is now clearly obvious: in the future, the weapon of choice to fight robots will be an aluminium baseball bat.

Re:Terminators (2, Funny)

Anonymous Coward | about a year and a half ago | (#42980957)

Until they take it from you and balance it on their heads while giving you a robotic pimp slap.

Re:Terminators (1)

Intrepid imaginaut (1970940) | about a year and a half ago | (#42981637)

How feasible would it be to encase these in donut or hemispherical shells, with grilles for airflow? The number of props is an obvious weakness, can we cover them up entirely?

Re:Terminators (1)

plover (150551) | about a year and a half ago | (#42981867)

The AR Drone (by Parrot) comes with two shells, one that's a simple body cover, and the other includes integrated rings around the propellers (called the "indoor" shell.) The idea is you determine the level of safety you require in the situation you're in, with safety either applying to the environment, to the plane, or both. The tradeoff is weight, which translates to reduced flight time.

In this case they're using a room with fabric drapes to absorb the impact of a stray rotor so they can maximize flight time.

Re:Terminators (1)

Frnknstn (663642) | about a year and a half ago | (#42983211)

I thought the white drapes were so that the drones could easily track the stick's position?

Re:Terminators (1)

plover (150551) | about a year and a half ago | (#42985609)

That could be. I've seen videos of them flying in rooms lined with cotton netting, too, though, where the builders were obviously trying to minimize damage to the copters. But that might just be old footage. The autonomous drones have gotten a lot more trustworthy and reliable as of late, so maybe they don't worry as much about crashing anymore.

And flying in an isolated room, they don't seem too worried about incidental damage. The video of the drone assembling the brick tower in a crowded art gallery, though, that one made me wonder why they didn't have a bit more safety equipment around it.

Re:Terminators (2)

tibit (1762298) | about a year and a half ago | (#42985703)

The drones don't track anything. I don't even know if they have an IMU. All position data is acquired using a video motion capture system. I'd think it may be Vicon with Tracker software.

Re:Terminators (1)

tibit (1762298) | about a year and a half ago | (#42985687)

They were flying these things apparently over people's heads in a public demo of putting together a brick "building". The room was full of spectators. It almost looked like a live art exhibit.

Re:Terminators (1)

NoSalt (801989) | about a year and a half ago | (#42983511)

I'm thinking oversized tennis racket.

Finally! (1)

nospam007 (722110) | about a year and a half ago | (#42980277)

A new way to throw a grenade through a tiny window on the 6th floor on the cheap.

Re:Finally! (0)

Anonymous Coward | about a year and a half ago | (#42980613)

Italians may do that, the Murican way is to level down the whole building.

Re:Finally! (3, Funny)

ArcadeMan (2766669) | about a year and a half ago | (#42980717)

Nope, that's the Daleks' way.

Wow (0)

Anonymous Coward | about a year and a half ago | (#42980311)

Very cool.

Why is it called an inverted pendulum? (0)

Anonymous Coward | about a year and a half ago | (#42980375)

Is there anything special to it (besides the two markers on it that are used for tracking) that makes it "not a stick" or does it just sound more sciencey? Even the visualization is just a stick with no markers to be seen.

Re:Why is it called an inverted pendulum? (3, Informative)

c0lo (1497653) | about a year and a half ago | (#42980665)

Because an inverted pendulum is a class and a stick is a particular instance (as it would be a drunkard). [wikipedia.org]

Re:Why is it called an inverted pendulum? (2)

Algae_94 (2017070) | about a year and a half ago | (#42983165)

That link points out that a human is also an instance of an inverted pendulum. I think I see some real potential for this now.

Re:Why is it called an inverted pendulum? (5, Informative)

MasseKid (1294554) | about a year and a half ago | (#42980771)

It's about sounding "science", as much as it a well defined scientific concept. An inverted pendulum is a well defined controls problem, where you take an unstable system and make it stable with your control laws. This is often solved in one dimension as part of undergraduate controls classwork with a cart and a stick balanced above it. The description of throwing and catching inverted pendulums perfectly describes what they are doing.

On the other hand, if they said they were throwing and catching a stick, I'd assume they were simply catching it. The balancing the unstable system with their control laws would not be assumed. Hope this helps.

Re:Why is it called an inverted pendulum? (0)

Anonymous Coward | about a year and a half ago | (#42983251)

I'm with the MasseKid on this one. For the first time in a LONG time, the title actually fully and accurately described the article!

Sure, it may require the knowledge of an "inverted pendulum", but this term was absolutely descriptive for me to quickly understand the nature of the project. If it had said "stick", I don't think I would have been as interested in the sheer computing power necessary.

Remember, this is supposed to be "News for Nerds". The effort should be made to make it as sciencey [sic] as possible!

CAPTCHA: enders ...case in point.

Re:Why is it called an inverted pendulum? (-1)

Anonymous Coward | about a year and a half ago | (#42981573)

"Better to remain silent and be thought a fool than to speak and to remove all doubt"
— Abraham Lincoln

You sir, should have kept your mouth shut.

Re:Why is it called an inverted pendulum? (2)

Joce640k (829181) | about a year and a half ago | (#42981819)

Typing "inverted pendulum" into google would have saved you some embarrassment

Not from not knowing what an inverted pendulum is, there's no shame in that.

The shame is from:
a) Not knowing how to use google
b) Trying to sound smarter than people who can do the math needed to toss inverted pendulums between quadcopters (which they designed and built).

Trail and error. (0)

Anonymous Coward | about a year and a half ago | (#42980389)

it's the combination of mathematical models with real-time trajectory generation, optimal control, and learning from previous iterations that allowed us to implement this
And one huge pile of broken robocoptors not seen in the vid.

Re:Trail and error. (1)

ArcadeMan (2766669) | about a year and a half ago | (#42980755)

It would have been funny to end the video with regular movie-style scrolling credits and have "42 quadrocopters have been harmed in the making of this film."

This is cool and all, but... (1)

wonkey_monkey (2592601) | about a year and a half ago | (#42980419)

...why do they have to call it an inverted pendulum instead of a stick?

Re:This is cool and all, but... (5, Informative)

lisaparratt (752068) | about a year and a half ago | (#42980507)

Because the round bits on the end act as pivots that are below the center of mass.

Re:This is cool and all, but... (0)

Anonymous Coward | about a year and a half ago | (#42980655)

because science!

Re:This is cool and all, but... (1)

Anonymous Coward | about a year and a half ago | (#42980943)

You haven't heard that term used? It's pretty common as a baby's-first-robotics-control problem.

BORING! (1)

Thud457 (234763) | about a year and a half ago | (#42982129)

Wake me up when they can do that with inverted compound pendulums.
Cirque du Soleil will probably put robots in the show when they can do that.

Or maybe an Aibo balancing on a big dog balancing on a CAM [myconfinedspace.com] . (Bonus if they can all "sing")

Re:BORING! (1)

fph il quozientatore (971015) | about a year and a half ago | (#42982205)

Wake me up when they can do that with inverted compound pendulums. Cirque du Soleil will probably put robots in the show when they can do that.

Don't worry, that's far beyond a robot's possibilities [youtube.com] .

Re:This is cool and all, but... (1)

c0lo (1497653) | about a year and a half ago | (#42980757)

Because they'll try balancing a human [wikipedia.org] next.

Re:This is cool and all, but... (1)

mspohr (589790) | about a year and a half ago | (#42981281)

Because it is an inverted pendulum.
It may just look like a stick to you but if you invert it, you may be able to see that it is a pendulum (mass on a pole with a fixed attachment point).

Re:This is cool and all, but... (1)

houghi (78078) | about a year and a half ago | (#42981291)

Trowing and catching a stick does not mean the same thing. All you need is something where the stick falls into.
A pendulum means it still needs to be 'standing'.

So it means that not only do you need to be where the stick is, you also need to keep it 'standing'. It is that second part that makes this interesting.

Re:This is cool and all, but... (0)

Anonymous Coward | about a year and a half ago | (#42981449)

It's not just a stick, it's an inanimate carbon rod ! ALL HAIL THE ROD.

Re:This is cool and all, but... (0)

Anonymous Coward | about a year and a half ago | (#42984909)

Because Fuck You, that's why!

Semi-related (0)

synapse7 (1075571) | about a year and a half ago | (#42980509)

These are a blast. [helimax-rc.com]

Fucking cool. (1)

Anonymous Coward | about a year and a half ago | (#42980661)

I'm impressed.

Skynet (1)

p51d007 (656414) | about a year and a half ago | (#42980721)

Self aware what day?

That is fucking cool (0)

future assassin (639396) | about a year and a half ago | (#42980735)

rehersed/pre programmed or not that is cool.

Incredible (1)

Sla$hPot (1189603) | about a year and a half ago | (#42980875)

I would never have expected robots to render circus artists jobless before anybody else.
Just add the Boston big dog, some micro drones and a snake bot and you've got a whole freaking robo-circus going.

double inverted? (0)

Anonymous Coward | about a year and a half ago | (#42980889)

I'd be more impressed if they could manage a double inverted pendulum, but clearly well executed engineering.

Motion capture studio (5, Interesting)

mill3d (1647417) | about a year and a half ago | (#42981125)

This looks like it was achieved using motion capture equipment, as seen by the usage of retro-reflective balls (see them shine at 1:44). If that's the case, it would imply that the computing was done remotely. Motion capture gear typically works at 120 frames per second, which would give the system enough time resolution to figure this out on the fly with a decent PC on the back-end.

It'll be a while before the quadrucopters can do this in their own but the program figuring out the catching move is impressive nonetheless.

Re:Motion capture studio (1)

Anonymous Coward | about a year and a half ago | (#42981283)

It'll be a while before the quadrucopters can do this in their own but the program figuring out the catching move is impressive nonetheless.

Not really. The benefit you get by transferring the data to an offside server is that it can perform pretty much any calculation. Once you have tried out the algorithm you actually want to do it shouldn't be that hard to build dedicated hardware in that size.

Re:Motion capture studio (2)

mill3d (1647417) | about a year and a half ago | (#42981493)

Measuring the pendulum's motion in 3D implies having at least stereoscopic vision. While I agree that specific hardware can be made to compute the proper flight once the position and velocity vectors of the pendulum are determined, the quadrucopter would still need to carry the gear required to acquire the pendulum.

As far as I can tell, that would at least require a 360 radar for object position detection and a couple of high speed, high resolution cameras mounted on 360 degree capable, fast moving tracking system. That part is what seems to be the most difficult, and I don't see that amount of gear mounted on this lightweight model without severe speed and agility penalties.

Re:Motion capture studio (2)

femtobyte (710429) | about a year and a half ago | (#42981635)

Or, process images from a swarm of individual quadrucopters into a 3D model of the space they inhabit. With enough members in the swarm, you don't need a full, fancy 360 camera setup on each one.

Re:Motion capture studio (0)

Anonymous Coward | about a year and a half ago | (#42983365)

Yay, computation on a single device is hard, let's make it harder by distributing the calculation in a heterogeneous swarm with higher latencies and dropped frames!!!

Re:Motion capture studio (1)

femtobyte (710429) | about a year and a half ago | (#42983477)

Getting semi-autonomous inherently unstable flying machines to catch and toss batons balanced on their end is *hard*. Fortunately, the people working on quadrucopter research don't shy away from *hard* things in the quest for *staggeringly awesome* things.

Re:Motion capture studio (0)

Anonymous Coward | about a year and a half ago | (#42981615)

Great point. It would be interesting to hear the machine vision point addressed by someone close to the research. Gathering and interpreting visual data with a small device like that really seems like the biggest and most interesting challenge to me as a layperson.

Re:Motion capture studio (0)

Anonymous Coward | about a year and a half ago | (#42981831)

Their motion capture equipment runs at up to 200 frames per second. If you wanted to do computer vision on board, the biggest challenge is limited processing power. Aerial vehicles like these quadcopters can't carry much if you want them to remain agile. The weight budget limits the vision system to something you'd find in a cellphone, and computation wise that's not much. On the positive side, they have easily recognizable markers on their objects and the lighting is static and known, so the actual vision algorithms aren't particularly difficult. The feat here is getting the kinematics under control, not the computer vision aspect.

Re:Motion capture studio (1)

tibit (1762298) | about a year and a half ago | (#42985831)

Agreed. My bet is that the motion capture is probably using recent Vicon cameras that do 2D tracking in hardware (on an FPGA or an ASIC, your pick). It's power hungry. Never mind the 3D tracking, in this case it'd be done by the tracker software running on the PC -- power hungry too. No point in putting nay of that on a quadcopter, imho.

Re:Motion capture studio (0)

Anonymous Coward | about a year and a half ago | (#42982909)

"it consists of a high-precision motion capture system, a wireless communication network, and custom software executing sophisticated algorithms for estimation and control. The motion capture system can locate multiple objects in the space at rates exceeding 200 frames per second. ... This information is fused with other data and models of the system dynamics to predict the state of the objects into the future. The system uses this knowledge to determine what commands the vehicles should execute next to achieve their desired behavior"

Re:Motion capture studio (1)

tibit (1762298) | about a year and a half ago | (#42985807)

The way they do it is state of the art at the moment. You pretty much don't want anything extraneous on the quadcopter. If their motion capture is 120Hz as you say, they'd be having an IMU on the quadcopter. If they can do 1000Hz, like they well should if they can afford it, they probably don't need an IMU -- just a completely receive-only quadcopter.

The quadcopters can't do any of that on their own at the moment because they'd need to know their position in space relative to each other and to the stick. You'd need lots of heavy image capture equipment on each quadcopter. This is a complicating issue that's entirely orthogonal to what they are doing. They are after control algorithms. Once you have that, you can play with moving sensors back to the flying platform. There's no point in putting the cart ahead of the horse, so to speak.

Fantastic! (0)

Anonymous Coward | about a year and a half ago | (#42981347)

If I am understanding correctly:

They are observing(how?) the staff, calculating trajectory and directing the second quadcopter(how?) to catch it. Each copter balances the staff. How? is it also optically controlled or is there some form of automated pressure or gyroscopic sensing occurring onboard the quadcopter itself?

At one point in the film there is a cloud of ???. Is this the staff being ground up due to an apparent miss?

Re:Fantastic! (2, Informative)

Anonymous Coward | about a year and a half ago | (#42981589)

At one point in the film there is a cloud of ???. Is this the staff being ground up due to an apparent miss?

The end of the staff has a small balloon on it, filled with powder -- see explanation further down the linked page. Sounds like a small hacky-sack with a rubber (grippy) surface. They call this a "damper" and one popped open.

Adding my compliments to the rest -- very cool demonstration of control theory.

Re:Fantastic! (1)

tibit (1762298) | about a year and a half ago | (#42985885)

The quadcopters are very basic, sensor-wise. They may have an inertial measurement unit onboard, or may not, I don't know. They probably know their battery state, and maybe motor current. A reverse channel from a quadcopter adds extra weight, I'd avoid it if I could. Other than that, everything is sensed by a standard motion capture (mocap) system that illuminates the scene with infrared light and tracks the reflective marker balls on the quadcopters and the pendulum.

They put small balloons filled with flour as dampers at the end of the pendulum. This is simply to provide something that will dissipate remaining kinetic energy when the stick hits the quadcopter -- there's always some velocity mismatch. If it was a bare stick, there wouldn't be enough friction to keep it on the quadcopter, and it would bounce away right after touching the quadcopter during a capture. Remember that our finger skin is pretty special when a bit moist -- it grips random things extremely well. When you have a carbon fiber stick and a plastic platform, it's a different story.

bicopter/tricopter (1)

arobatino (46791) | about a year and a half ago | (#42981389)

Can it be done with a tricopter? Or a bicopter with propellers that pivot?

Re:bicopter/tricopter (1)

udippel (562132) | about a year and a half ago | (#42981793)

Interesting question, though as far as I understand that's not what the project was about. To my understanding, the positions and movements are continuously calculated off-site and then, irrespective of the flying objects, any flying object steered, maneuvered and hoovered about to attain the calculated position and flight path. And then maintain constantly what is fed into the Xcopter to balance the rod (pendulum).
I guess that the quadrocopters were just the easiest and fastest to be maneuvered around, like tilted into any direction without any secondary motion control.

All it needs is the über power source (1)

RogueWarrior65 (678876) | about a year and a half ago | (#42981617)

That is pretty impressive but it also serves to reinforce the fact that without the über power source, it's just a nifty demo. This is what I keep hearing from SWAT teams who either spend a ton of money (e.g. > $25k) buying one or are looking at getting one and then they discover that they can't put a camera up in the air for hours at a time without landing to change batteries.

And did anyone else read "Pole Acrobatics" and have a totally different expectation? ;-)

Re:All it needs is the über power source (1)

athmanb (100367) | about a year and a half ago | (#42984827)

With how smart these choppers are getting this shouldn't even be a problem. Just buy three of them for any two jobs and have them find their own schedule to "sleep" when they need to so that there's always at least the required number up in the air.

Re:All it needs is the über power source (1)

RogueWarrior65 (678876) | about a year and a half ago | (#42985653)

It's hard enough for a cash-strapped department to find $25,000 for one. You'd need at least two and enough batteries in various states of being recharged in order to keep eyes on all the time. I know plenty of SWAT guys that would rather spend the money equipping their entire team with thermal night vision.

Re:All it needs is the über power source (1)

tibit (1762298) | about a year and a half ago | (#42985889)

Those quadcopters are dumb slave devices. They have no built-in intelligence of any sort.

Re:All it needs is the über power source (0)

Anonymous Coward | about a year and a half ago | (#42985547)

Not a problem. Have two copters. When one is getting tired, send up the second one to relieve it. Then land the first one and change its batteries.

As impressive as this is ... (1)

Rambo Tribble (1273454) | about a year and a half ago | (#42981885)

... I imagine stupid people tricks will remain more popular than smart robot ones.

Non-Science guy questions... (1)

MugenEJ8 (1788490) | about a year and a half ago | (#42981923)

Is the actual balancing performed based solely on the forces applied to the sending/receiving actors? How necessary are the data markers on the stick? I'm wondering that if the two actors knew where each other were in space, and based on the balancing the sending actor has to perform couldn't the receiving actor make a guess where it needs to be in any case? Could I (as an actor in this scenario) make an educated guess as to the length of the stick based on the corrections I have to perform in order to keep it upright? Of course I may be asking questions that can't be answered because we don't have the full picture from the demonstration.

Re:Non-Science guy questions... (0)

Anonymous Coward | about a year and a half ago | (#42983287)

My guess is... that yes, you can guess all those things, but I'm almost certain that you can't guess them precisely enough for the setup to function under any circumstances. You would need to know future corrective movements of the throwing to get a reading close to being precise enough to predict the motion of the stick.

Getting a bit more useful (0)

Anonymous Coward | about a year and a half ago | (#42982119)

A few more steps down the road with this kind of development and they should be able to make them fly through an obstacle course with a non-rigid sling load (weight on a string) without hitting anything. (Something right now that takes a human pilot to deal with, and requires plenty of experience as well. Definitely not easy as a lot of helo wrecks are due to people trying this without having enough clue of how to compensate for a freely shifting load.) That would lead to scaled up models having lots of use in many practical applications. But right now, just keep taking some baby steps with a key emphasis on manueverability. I'm guessing that using a rigid object while starting out is a much easier way to deal with a shifting center of gravity because it doesn't change much with harmonics or having its weight offset by air resistance.

I call this a secondary sexbot milestone (0)

GodfatherofSoul (174979) | about a year and a half ago | (#42982131)

They've now got the mopping algorithm locked up; enough with the kitchen use cases get back to the bedroom guys.

1:33 (1)

ThatsNotPudding (1045640) | about a year and a half ago | (#42982181)

A puff of smoke at 1:33; I think someone lost a bit of propeller to the pendulum.

Re:1:33 (0)

Anonymous Coward | about a year and a half ago | (#42983489)

The end of the staff has a small balloon on it, filled with powder -- see explanation further down the linked page. Sounds like a small hacky-sack with a rubber (grippy) surface. They call this a "damper" and one popped open.

Adding my compliments to the rest -- very cool demonstration of control theory.

Re:1:33 (0)

Anonymous Coward | about a year and a half ago | (#42983915)

It was a "shock absorber" blowing out. The shock absorbers were balloons filled with flour attached to the end of the rod.

Ridiculous (1)

quintesse (654840) | about a year and a half ago | (#42982283)

And I still can't even get my quadcopter for a normal spin without crashing it into the nearest wall or tree!
How the heck can I get mine to hover at least somewhat in one place? I know these use the cameras for real precise tracking, but mine is the exact opposite it seems. Grrrr

Re:Ridiculous (1)

ThreeKelvin (2024342) | about a year and a half ago | (#42985525)

The branch of engineering you're looking for is called "Control Theory".

Re:Ridiculous (1)

quintesse (654840) | about a year and a half ago | (#42985649)

Oh, I thought it was called "lots of practise" ;)

Re:Ridiculous (0)

Anonymous Coward | about a year and a half ago | (#42986275)

I totally feel you. Some problem with the ardupilot on take off here.
The post made feel like the dumbest nerd on earth.

Re:Ridiculous (1)

cffrost (885375) | about a year and a half ago | (#42987399)

I totally feel you. Some problem with the ardupilot on take off here.
The post made feel like the dumbest nerd on earth.

Better a dumb nerd than a smart philistine.

Wheeee! (1)

subnomine (849148) | about a year and a half ago | (#42983031)

Amusement park rides of the future are going to be awesome!

remember this... (1)

jds91md (2439128) | about a year and a half ago | (#42983767)

As amazing as this is (and it IS friggin' amazing), remember that the human brain does this throw, catch, reposition, recalculate, and respond stuff effortlessly. Just play catch with a ball and your 5 year old child. Animals with pea-sized brains do it great, too! -- Josh

Re:remember this... (1)

tibit (1762298) | about a year and a half ago | (#42985915)

Those quadcopters are a bit faster than humans arms are, and things are moving towards getting everything even faster still.

Juggle Flaming Chainsaws (1)

locopuyo (1433631) | about a year and a half ago | (#42983993)

Very good. Now let's do it with flaming chainsaws.

Quadrocopter? (0)

Anonymous Coward | about a year and a half ago | (#42986937)

It's "quadcopter" not "quadrocopter" you Ivory Tower morons. Talk about being out of touch with reality. No one in the hobby calls them quadrocopters; not in any language.

Re:Quadrocopter? (0)

Anonymous Coward | about a year and a half ago | (#42987855)

you are calling the people who engineered this "morons"? that's gotta be the funniest thing i've heard today

Too much calculation (0)

Anonymous Coward | about a year and a half ago | (#42987233)

I get the impression from the article that getting this to work involved a lot of detailed calculations. I feel that we should be able to do this instead using a feedback loop where the quadricopters can sense where they need to be and make small adjustments themselves as necessary. Humans and animals do this all the time without using complicated mathematical models.

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