height control

[wawachen]

I have a question whether we can add our external positioning signal to do the height control based on your architecture. As for now, it uses the z-range to control height which is not very suitable for some cases which don't have a flat surface.

[JGSuw]

Hi Oliver,

Yes of course this is possible, although I need to add a new function to the library for this. I'm happy to do this work, since it will be a useful addition to this repository, and also not much labor is required.

What we have done in the past is use motion capture as our positioning signal: then we implemented a PID controller that uses position errors to determine attitude (pitch, roll, and yaw setpoints) and thrust commands for the vehicle. This works quit well for closed-loop position control, since about a hovering equilibrium the dynamics of the vehicle's XYZ coordinates are approximately linear in attitude and thrust.

Alternatively, it is also likely possible that we could send your external position signals directly to the vehicle, so that the control is computed on the crazyflie itself. However, I'm less certain how this would be done. It might take more time to determine if it is possible.

Presently are you using python 2 or python 3? I would like to know so that I can make these changes to the branch of the code which you might use first.

[wawachen]

Thanks for your reply.
Currently I am using python2.

[wawachen]

could please give me an evidence of how to add new function of enabling external device like lighthouse to achieve the velocity and position control?