Bitcraze Forums

Hi,
I am using crazyflie 2.0 without LPS. I am trying to send external data from a python client using a motion capture system (optitrack) in my lab.
Whenever I try to send external position, the quad is restarting. In my python client, I am sending external position as follows: `cf.loc.send_extpos([0, 0, 0])`. If I remove this line of code, the quad does not restart and continues to log data properly.
Also, It seems that the kalman filter is not working properly. I get x = 0 and y = 0. z is always identical the barometer measurement. I wonder if these issues are related. If possible, could you please provide details on how to enable the kalman filter? I have seen in some other posts that I have to set ESTIMATOR=kalman in the config.mk. I don't have a file named "config.mk". Instead, I have "config.mk.example" (in /tools/make).
I am building my project from eclipse ( using the VM ). Could this be a problem?

Any help is appreciated! Please let me know if you need more information.
Regards!

You do not have the kalman filter enabled which explains why you are not getting any positions. You should create tools/make/config.mk or rename config.mk.example into config.mk. Then you can add ESTIMATOR=kalman, then run 'make clean', 'make', 'make cload' in the console and you should have a Crazyflie with Kalman filter enabled. 'make clean' is required each time you modify the config.mk file.

The Crazyflie should never crash (famous last word ...) so this is a bug. I created a ticket for it: https://github.com/bitcraze/crazyflie-f ... issues/342.

Thanks for the quick reply. I enabled the kalman filter as you said. I quickly tested it without the motion capture system, and I can now see the position values drift quickly. I think the problem is solved, but I will test it tonight at the lab using the motion capture system; and I will update you with the result.

Again thank you!

Hi,

May not be very related to your question but i'm also trying to send external position data to Optitrack. Is there a tutorial on how to approach this method of Localization. On Optitrack website it's recommended to use NatNet SDK . Is this what you did?

Thanks

If you use ROS, you can use crazyflie_ros (https://github.com/whoenig/crazyflie_ros) or the crazyswarm (https://github.com/USC-ACTLab/crazyswarm). Both have been used successfully with OptiTrack and come with some (limited) documentation on how to use it.

If you use python, a good approach might be VRPN - OptiTrack (and VICON) have VRPN servers build-in, and there are VRPN python modules (https://github.com/vrpn/vrpn/wiki).