Multiple drones and LPS accuracy

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bartvandenberg
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Multiple drones and LPS accuracy

Post by bartvandenberg » Tue Jan 03, 2017 4:52 pm

Hi all, Please see the video below of our crazyflie (tracked by lps) hovering at a fixed point in space. Our final goal is to have four drones flying in a tight space (1,5 x 1,5 x 1,5m). For this we need a very accurate setup. Does anyone have experience with multiple drones in a tight space? And are there any tips & tricks to increase the accuracy of LPS?

Video: https://www.youtube.com/watch?v=n53zySC ... e=youtu.be



arnaud
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Re: Multiple drones and LPS accuracy

Post by arnaud » Wed Jan 04, 2017 9:20 am

Hi,

X/Y looks quite OK but the Z accuracy is quite bad. We have seen that reducing vibration can increase a lot the Z accuracy, you can try to balance your propeller and if you had crash before maybe some motor are vibrating a bit much.

The current position controller is not ideal and there has been work on new feed-forward controllers that should land in the master branch (hopefully) soon.

arnaud
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Re: Multiple drones and LPS accuracy

Post by arnaud » Thu Jan 05, 2017 9:51 am

Hi, We just discovered and fixed a bug that should improve the LPS performance: viewtopic.php?f=17&t=2279, this should help with the stability.

bartvandenberg
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Re: Multiple drones and LPS accuracy

Post by bartvandenberg » Fri Jan 06, 2017 10:31 am

Thanks Arnaud, we'll check this out. I'll also fly again with a new copter because the one you saw in the video crashed a number of times.

tariqse
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Re: Multiple drones and LPS accuracy

Post by tariqse » Sun Jan 08, 2017 7:36 am

Hey bart,

Nice work. I was wondering if you had the chance to test the drone after the fixed bug that arnaud mentioned.

Good luck.

bartvandenberg
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Re: Multiple drones and LPS accuracy

Post by bartvandenberg » Mon Jan 16, 2017 4:33 pm

Sorry for the delay. Yes we have updated the firmware of the Crazyflie. It does indeed perform better. Especially on the Z axis. But we're not sure yet if it's a good idea to let 4 quadcopters fly together in a tight space.
https://www.youtube.com/watch?v=uYpqou_ ... e=youtu.be

arnaud
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Re: Multiple drones and LPS accuracy

Post by arnaud » Wed Jan 18, 2017 9:53 am

Are you using TDoA or two way ranging? It still looks quite shaky, I think we are getting better hover stability than that. 4 CFs in a tight space might indeed be challenging.

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