Oh, to have a half-million-dollar Vicon motion capture system. Look at what you can do with it (in the lab)!

 

From IEEE Spectrum:

"The University of Pennsylvania's GRASP Lab, famous for those crazy quadrotors that can fly through windows and hula hoops, has been working on getting groups of the robots to fly together in formation. Just like with a formation of fighter jets, there's a leader robot in each squad along with several follower robots. The followers have just two jobs: follow the leader, and preserve the shape of the formation.

Being able to do this is all about communication, as Professor Nathan Michaeldiscussed today at the IEEE International Conference on Robotics and Automation (ICRA) in Shanghai. As he and fellow researchers Matthew Turpin and Vijay Kumar have discovered, the robots have to not just know exactly where they are, but they also have to broadcast that information to their neighbors to maintain the integrity of the formation. This processing is all done on each individual quadrotor, so there's no all-seeing computer watching everything and telling each robot where to go. The accuracy is impressive: 50 percent of the time the quadrotors are within a mere two centimeters of where they should be.

So what happens when some robots can't talk to each other? If a robot fails for some reason, it's able to bow out from the formation gracefully, and the other robots can move on without it, preserving the shape of the formation. You can see an example of this in the above vid. It's an important capability: part of the advantage of having a group (or a swarm) is that it can be resilient to individual failures, but to harness this resiliency, you need to not have one failure cause a disruption to the rest of the group."

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Comment by Russell B. Sutton on May 9, 2011 at 4:03pm
This is really cool stuff.   Maybe we can get there with future AC-3  or 4, but with out the lights.  I like how the bad quad is able to detect something is wrong and land it self.  This could be useful in the future of AC-xx.
Comment by Matt on May 9, 2011 at 5:59pm
I think we should try to create a DIY motion capture systmem so we all dont have to cough up half a million to achieve the same results. Im not very knowledgeable about these motion capture systems but their results are rather impressive. If anyone knows more about these things I would love to hear. I know there is a significant mark-up when selling things to schools or universities so the actual price of make a thing could be less
Comment by Russell B. Sutton on May 9, 2011 at 7:07pm
@ Matt   Why not just put the motion capture system on the Quad like the AR-drone uses.  It's the cheapest and easiest    The Quads in the video are limited in the fact that they only work under the lights.  Witch is great but not really automonous.  It is good for quads working together though.   
Comment by MarcS on May 10, 2011 at 2:35am

Russel you are exactly right with your point that all of these demonstrations only work "under the lights" meaning the vicon enabled room. Thats where I see the drawback of all these demonstrations, they are limited to a very small, controlled volume.

In this context, the words "there's no all-seeing computer watching" seems a little disturbing, because actually there is one... It would also be interesting, if the copters do have IMU at all (could also be done by the Vicon) and what is meant by communications failiure (complete shut-off or only communication between the Quads).

On their page they say they want to do this outdoor in the future. That is really going to be interesting to see!!

Hope to get videos of that soon.

Comment by I.S. on May 10, 2011 at 3:46am

As others mention, I also feel that controling quads in a mm precision environment is somewhat cheating  far from real world.

On the other hand, though, I see it totally logical to develop control algorithms and fine tuning them under a precisely controlled area and then move to the outside/real world to test them.

@Matt

http://www.vicon.com/

This is the kind of thing that "if you ask the price, you can't afford it"

Comment by Jack Crossfire on May 10, 2011 at 4:24am
Chris Anderson was the 1st person we ever heard say Quad Copter instead of Quad Rotor.  Quad Copter then became the standard for hobbyists, but academia, still in the $20,000 Ascending Technologies world, still says Quad Rotor.
Comment by Matt on May 10, 2011 at 12:41pm

@ Russell, sounds like a good plan but the problem is actually creating an affordable system that is almost as precise as the one in the video.

 

@ I.S , I looked at your link and it seems like the cheapest system started at $10,000 (I'm not willing to pay that if all I am looking to do is created a bunch or coordinated quadcopters). Thats why I want to create a DIY system, if possible.

Comment by I.S. on May 10, 2011 at 1:24pm

DIY mocap doesn't look easy to me.

You need high fps cameras and coms links and pretty high processing power put together,

ah! and make it all that very low latency too!

Looks to me like a deep dive in SW and HW.

maybe so else could visualize the path to success much better/easier than me.

Comment by MarcS on May 10, 2011 at 3:53pm

Getting a system as the commercial one is quite hard, sure.

But there are some people having achieved quite good results using Webcams, LED´s and Matlab...

This one has already been posted, I think (Willa is also online here :-): http://shrediquette.blogspot.com/2009/09/matlab-source-code.html

If someone could get that ported to something like OpenCV, add multi-Camera support and calibration... And test for usable cameras (with short lag, thats a big drawback of most USB webcams)... This would be a great system. If you combine that with an onboard IMU (which I´m not sure if they do with the VICON) you could achieve results that come close.

On the other side, why not get outside? Much more fun and challenge :-)

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