Question about controller for Crazyflie

[thanhvu94]

Hello, I'm working with Crazyflie and I have some theoretical questions about the controller of the Crazyflie:

1. As from what I know, quadcopter is a very non-linear system, why for Crazyflie it is possible to control it with PID controller (linear)?
2. Why the controller cannot be PI, PD, but it has to be PID?
3. Is there any work to apply a non-linear controller to Crazyflie?

Thank you so much, I would appreciate any helps.

[binx]

Hi,

Recently I'm reading this technical report about Crazyflie. I hope this could answer part of your questions. This technical report is great, it elaborates from the very beginning. If you are just getting started with Crazyflie, I think it would make some sense to you.
https://arxiv.org/pdf/1608.05786.pdf

[arnaud]

Hi,

For 1. and 2. I am sure you can find very good explanation and paper online that will go in depth as of why a PID controller works fine for a quadcopter. I far as I know PID controller is very standard when it comes to controller for remote controlled quadcopter.

for 3. see this forum answer for 2 existing non-linear controller implementation for the Crazyflie: viewtopic.php?f=11&t=2411#p12210. The paper mention above seems to describe a 3rd one.