Climbing During Forward Transition

ozanyuceol · March 10, 2021, 1:44pm

Dear all,

During forward transition, the altitude is held constant as defined in the Take-off WP. However, I want it keep climbing to the altitude defined in the waypoint which is coming after “VTOL Take-off”.

May someone guide me where in the code I need to do this modification? I tried applying altitude offsets at a few places, but another logic overrides my offsets, and keeps the altitude constant during forward transition.

Regards.

notoriou5 · March 11, 2021, 7:01am

I think what you are looking for is here:

github.com

PX4/PX4-Autopilot/blob/8816601efb8c26b709a2c1117479af115436155b/src/modules/flight_mode_manager/tasks/Transition/FlightTaskTransition.cpp#L58


}

bool FlightTaskTransition::update()
{
	bool ret = FlightTask::update();
	_acceleration_setpoint.xy() = matrix::Vector2f(0.f, 0.f);
	// demand zero vertical velocity and level attitude
	// tailsitters will override attitude and thrust setpoint
	// tiltrotors and standard vtol will overrride roll and pitch setpoint but keep vertical thrust setpoint
	_position_setpoint.setAll(NAN);
	_velocity_setpoint(2) = 0.0f;

	_yaw_setpoint = NAN;
	return ret;
}

_velocity_setpoint(2) is the value which commands the thrust. Maybe its enough to set it to NAN, maybe you need to fill it with another value (not 100% sure there…)

ozanyuceol · March 11, 2021, 3:30pm

@notoriou5 thanks!

I will try and give a feedback to this.

mohammad · March 13, 2021, 10:31am

This is related to:

take off altitude and waypoint transition altitude must be different for this feature.

ozanyuceol · October 22, 2021, 7:44am

Thanks @notoriou5 !

This is the value should be set for climbing transition (negative is upwards).

However this function is entered in both forward and backward transitions. Therefore it is climbing during back transition as well. What is the flag which determines that aircraft is forward or back transitioning? I will keep the vertical velocity setpoint as zero during back transition.

igal-colugo · June 4, 2023, 1:04pm

hi,
i changed the _velocity_setpoint(2) hard coded to -3 just to see it works - it works well bu during the climb the plane seems to be drifting - can anyone give an advice about it?

mikifare · January 11, 2024, 7:52pm

Thanks for the update

fethiye tours

Charles_Armer · February 14, 2024, 2:44pm

Speaking from experience, don’t forget to keep in mind that climbing while accelerating creates a very large power draw on the system. Usually, aircraft have the power to climb or accelerate, but not both at the same time. Keep an eye on thrust values, and ESC temps. If your vehicle doesn’t have an extraordinarily high power to weight ratio, you may be risking a catastrophic failure.