Will standard PX4 Flight Modes be available when deploying own attitude controller?

In a current project we develop our own Controll Allocation and Attitude & Rate Controller for a blended wing body fixed wing drone.

Will the Flight Modes as described here be still available?

Does anything need to be kept in mind for that?

If not: Would it be feasable the develop our own flight modes in simulink with the possibility to switch between them with a uOrb message and deploy them with the Position Controller? Does not really seem ideal to me, but I struggle to see a different workaround.

Thank you!

Answer 1

[Arun Mathamkode]

As per my understanding, you should be able to use the trajectory_setpoint uORB topic to get the desired position, velocity, and yaw setpoints irrespective of the flight mode. This topic is published by the Flight Mode Manager based on the currently selected flight mode, so it already reflects the mode logic and trajectory smoothing. I have not yet tried this at my end but you can give it a try. I aslo assume you are using PX4 v1.14.3.

In Simulink, you can:

• Subscribe to trajectory_setpoint to read the commanded setpoints.
• Subscribe to estimator outputs like vehicle_local_position (and optionally vehicle_attitude) to get the current state.
• Implement your own position and attitude controllers in Simulink using these inputs.

This approach allows you to keep PX4’s flight mode handling intact while replacing only the control logic.