[Paparazzi-devel] angular acceleration control and motion capture

[Fabrizio Boriero]

Hi everybody!
I am new here so greetings to the community!

I want to ask you if it is possible, with paparazzi, to control a
quadrotor in angular accelerations.
I need to use and external motion capture (Optitrack) to build a
position control on altitude and Yaw direction, but I want also to
control the roll and the pitch angles with an acceleration control.

So the simple question is: with Paparazzi, is it possible to send
acceleration controls from a ground station (PC) holding the attitude?

Many thanks!
Fabrizio

[Ewoud Smeur]

Hi Fabrizio,

Welcome to Paparazzi! Indeed it is possible to control the angular accelerations of the drone, using INDI. It derives the angular acceleration from the gyroscope measurement through differentiation, and increments control inputs in order to achieve the desired angular acceleration. It is explained in this paper:
https://www.researchgate.net/publication/288856862_Adaptive_Incremental_Nonlinear_Dynamic_Inversion_for_Attitude_Control_of_Micro_Air_Vehicles

How you can enable this in Paparazzi is described here:
https://wiki.paparazziuav.org/wiki/Working_with_INDI

In fact, I would say it is easier to use the attitude estimation onboard the drone instead of the PC. As is described in the links above, you can specify two gains that will let you go from an attitude error -> gain -> angular velocity error -> gain -> desired angular acceleration.

The relevant source file is: https://github.com/paparazzi/paparazzi/blob/master/sw/airborne/firmwares/rotorcraft/stabilization/stabilization_indi_simple.c

Hope this helps.

Regards,

Ewoud Smeur
________________________________
Van: Paparazzi-devel <paparazzi-devel-bounces+ewoud_smeur=***@nongnu.org> namens Fabrizio Boriero <***@gmail.com>
Verzonden: vrijdag 5 januari 2018 10:05
Aan: paparazzi-***@nongnu.org
Onderwerp: [Paparazzi-devel] angular acceleration control and motion capture

Hi everybody!
I am new here so greetings to the community!

I want to ask you if it is possible, with paparazzi, to control a
quadrotor in angular accelerations.
I need to use and external motion capture (Optitrack) to build a
position control on altitude and Yaw direction, but I want also to
control the roll and the pitch angles with an acceleration control.

So the simple question is: with Paparazzi, is it possible to send
acceleration controls from a ground station (PC) holding the attitude?

Many thanks!
Fabrizio

[Fabrizio Boriero]

Post by Ewoud Smeur
Hi Fabrizio,

Hi Ewoud,

Post by Ewoud Smeur
Welcome to Paparazzi!

Thanks a lot :)

Post by Ewoud Smeur
Indeed it is possible to control the angular accelerations of the
drone, using INDI. It derives the angular acceleration from the
gyroscope measurement through differentiation, and increments control
inputs in order to achieve the desired angular acceleration. It is
https://www.researchgate.net/publication/288856862_Adaptive_Incremental_Nonlinear_Dynamic_Inversion_for_Attitude_Control_of_Micro_Air_Vehicles
https://wiki.paparazziuav.org/wiki/Working_with_INDI
In fact, I would say it is easier to use the attitude estimation
onboard the drone instead of the PC. As is described in the links
above, you can specify two gains that will let you go from an attitude
error -> gain -> angular velocity error -> gain -> desired angular
acceleration.
https://github.com/paparazzi/paparazzi/blob/master/sw/airborne/firmwares/rotorcraft/stabilization/stabilization_indi_simple.c
Hope this helps.

Wow great! You gave me a lot of useful information!
Thanks a lot to everybody for your help!

Regards,
Fabrizio

Post by Ewoud Smeur
Regards,
Ewoud Smeur

[Ewoud Smeur]

Hi Fabrizio,
________________________________
Van: Paparazzi-devel <paparazzi-devel-bounces+ewoud_smeur=***@nongnu.org> namens Fabrizio Boriero <***@gmail.com>
Verzonden: vrijdag 5 januari 2018 10:05
Aan: paparazzi-***@nongnu.org
Onderwerp: [Paparazzi-devel] angular acceleration control and motion capture

Hi everybody!
I am new here so greetings to the community!

I want to ask you if it is possible, with paparazzi, to control a
quadrotor in angular accelerations.
I need to use and external motion capture (Optitrack) to build a
position control on altitude and Yaw direction, but I want also to
control the roll and the pitch angles with an acceleration control.

So the simple question is: with Paparazzi, is it possible to send
acceleration controls from a ground station (PC) holding the attitude?

Many thanks!
Fabrizio

[Hector Garcia de Marina]

Hi Fabrizio,

In principle, you can derive the moments in the rotorcraft from the
gyroscopes.

I am not sure whether somebody has done what you request in Paparazzi. Is
it possible? Sure! In fact, you can already send from the ground *linear*
acceleration commands to a rotorcraft. It is an experimental branch, but I
guess it will be available in master branch soon.

(I see that Ewoud already replied, he knows better about the details xD).



On Fri, Jan 5, 2018 at 10:05 AM, Fabrizio Boriero <

Post by Fabrizio Boriero
Hi everybody!
I am new here so greetings to the community!
I want to ask you if it is possible, with paparazzi, to control a
quadrotor in angular accelerations.
I need to use and external motion capture (Optitrack) to build a
position control on altitude and Yaw direction, but I want also to
control the roll and the pitch angles with an acceleration control.
So the simple question is: with Paparazzi, is it possible to send
acceleration controls from a ground station (PC) holding the attitude?
Many thanks!
Fabrizio
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