Parameters in crazyflie2.xacro

[gsilano]

Parameters in crazyflie2.xacro

[gsilano]

The parameter values of the Crazyflie have been taken from this repository by the same research group of

W. Honig and N. Ayanian, “Flying Multiple UAVs using ROS,” in ¨ Robot Operating System (ROS): The Complete Reference (Volume 2), A. Koubaa, Ed. Springer International Publishing, 2017, pp. 83–118.

For more details, see the reference book chapter.

[Tonirayn]

Yeah I have already checked the papers but I found strange that the drag is so high since it is equal to the IRIS

[gsilano]

Yes, you are right. Probably such a value is not fair but, first, it would be of interest to understand how much this value can influence the system dynamics (take a look at the Gazebo plugins) and then if someone already addressed its estimation. If you could investigate it, it would be awesome.

[Tonirayn]

Ok I have already done some experiments for making flip where the drag take much more influence and I think that a proper value it will be 1.066428e-06 according to Forster. Indeed it is used here. I think that with this value the motion should be better also for standard planar motion

[gsilano]

Okay, thanks! I will test it as soon as I have time and let you know if this somehow affects the existing control algorithms. So, I will integrate the new value into the repository.

[Tonirayn]

Just to be clear maybe It's worth also to update the other values,also according to the Forster, as follow:

 <!-- Forster's -->
  <xacro:property name="motor_constant" value="1.71465181e-08" /> <!-- [kg m/s^2] -->
  <xacro:property name="moment_constant" value="0.004459273" /> <!-- [m] -->
  <xacro:property name="time_constant_up" value="0.0125" /> <!-- [s] -->
  <xacro:property name="time_constant_down" value="0.025" /> <!-- [s] -->
  <xacro:property name="max_rot_velocity" value="3052" /> <!-- [rad/s] -->
  <xacro:property name="rotor_drag_coefficient" value="1.066428e-06" />
  <xacro:property name="rolling_moment_coefficient" value="0" /> 

[gsilano]

Just to simplify the check process, could you also indicate the pages where you found these values?

[Tonirayn]

sure, in the overview result page 57

[gsilano]

Hi @Tonirayn!! Sorry if I did not reply to you, but this very is very full of work for me. I will manage to test your suggestions as soon as possible.

[gsilano]

Eventually, I decided to put the file in the repository (see the CHANGELOG file for more details). Right now, I don't have time to look at the plots, controller performance, and check everything with an identification process. However, I thought it was useful to have such a file as an option. Thanks for your help. Your contribution is now part of CrazyS and your name is on the contributor list :-)

[Tonirayn]

ok thanks