MPC: LAND: Split Landing out of FlightTaskAuto into FlightTaskLand

[Claudio-Chies]

Solved Problem

The #23546 did not consider the case when we trigger land from Altitude or Manual FlightTask, where the commanded velocity can greatly exceed the velocity possible in FlightTaskAuto.

Solution

• Creation of a Landing Flighttask
• adding of a "stop" motion primitive, to slow down the vehicle to a complete stop given any initial velocity.

With this PR, we are splitting the Landing Logic into a separate FlighTask called FlightTaskLand, and handle the landing logic in there.

Test on Hardware

Changelog Entry

For release notes:

Bugfix: Multicopter vehicles slow down smoothly when transitioning from a manual flight mode to the landing flight mode.

Dependent PR's

• MPC: AUTO: Emergency Braking velocity setpoint fix #23757

Test coverage

• Tested in SITL Flightreview
• Tested on Hardware Flightreview

[dakejahl]

I wonder how does this effect PrecisionLand? The precland logic lives in navigator as a submode, and I believe puts the vehicle into FlightTaskAuto with a land setpoint type. Something to keep in mind!

[Claudio-Chies]

@dakejahl

I wonder how does this effect PrecisionLand? The precland logic lives in navigator as a submode, and I believe puts the vehicle into FlightTaskAuto with a land setpoint type. Something to keep in mind!

I now made it so that Landing Flightmode goes into FlightTaskLand, and Precision landing remains in FlightTaskAuto.
This way we can/should split out precision landing into its own flight task in the future, or also integrate it into FlightTaskLand.

I wasn't able to also integrate precision landing into it, as i dont have the means to test it, and FlightTaskLand is currently not set up to handle movement around to setpoint triplets as FlightTaskAuto. it just brakes, and lands.