after get time diff with two anchors, python do what things ?

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justinleeyang
Expert
Posts: 186
Joined: Mon Dec 28, 2015 5:07 am

after get time diff with two anchors, python do what things ?

Post by justinleeyang »

hi, arnaud:

from the crazyflie-firmware, after get diff with anchors, the information send to PC client python. Because I ldon't learn python, so I don't know the later
things, are you introduce the python's processing?
arnaud
Bitcraze
Posts: 2538
Joined: Tue Feb 06, 2007 12:36 pm

Re: after get time diff with two anchors, python do what things ?

Post by arnaud »

Hi Justin,

All processing for TDoA is done in the Crazyflie: difference of distances between anchor is calculated by the LPS driver and sent to the Kalman filter for position estimation.

Maybe you can give us more precision about what data or code you are wondering about?
justinleeyang
Expert
Posts: 186
Joined: Mon Dec 28, 2015 5:07 am

Re: after get time diff with two anchors, python do what things ?

Post by justinleeyang »

hi, arnaud:
I want to know how to get 3D position of space. so you mean that when crazyflie get the time diff to EKF, then calculate the (X,Y,Z) ?
arnaud
Bitcraze
Posts: 2538
Joined: Tue Feb 06, 2007 12:36 pm

Re: after get time diff with two anchors, python do what things ?

Post by arnaud »

Hi,

Yes, the EKF in the Crazyflie is calculating the X,Y,Z position estimates.

Distance difference enters there: https://github.com/bitcraze/crazyflie-f ... aTag.c#L84
And we get X,Y,Z on the other end: https://github.com/bitcraze/crazyflie-f ... 1093-L1098
justinleeyang
Expert
Posts: 186
Joined: Mon Dec 28, 2015 5:07 am

Re: after get time diff with two anchors, python do what things ?

Post by justinleeyang »

hi, arnaud:

according to my privious understanding, the EKF only estimate non-linear data, from your view, EKF also get the 3D position.
so I need get more the EKF information. thanks!
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