PX4 SITL to Gazebo rotor velocity bridge

PX4 Autopilot
1

Good day

I want to figure out how PX4 and gazebo talk to each other to determine how the rotors act in simulation. If I understand correct, the motor plugin for Gazebo takes in motor speed (in rad/s) and uses this to work out things such as thrust and torque from the constants I provide in the plugin.

However, I am unable to find how and where PX4 computes these rotor velocities which Gazebo must use. As far as I can find, it is still normalized values. I believe that this is a crucial part to creating a good simulation which acts like my drone.

2

Does this help?

3

Yes! Thank you very much.

According to this " HIL_ACTUATOR_CONTROLS" is the only message that PX4 sends to the Sim. This still seams to be a normalized commands according to the documentation. It then still must be transformed to a rotor speed somewhere in the Gazebo code. I have not yet found this step.
The reason why I want to see this step, is to determine if the simulation uses a linear model for thrust output or not.