Add support for quadtailsitter in SITL Gazebo

[Jaeyoung-Lim]

Describe problem solved by this pull request

The current tailsitter model has control surfaces, and a control surface-less tailsitter was not available for testing in simulation

Describe your solution

This PR adds support for a quadtailsitter, which models the HEQ SWAN K1.

The 3D mesh was provided by Holybro

Test data / coverage

Tested in SITL Gazebo

make px4_sitl gazebo_quadtailsitter

Additional context

• Depends on Enable motor controls for tailsitter VTOLs in fixed wing mode (enable Quad Tailsitters) #20511

[sfuhrer]

Very cool push, the model looks nice! But doesn't really work in FW for me, does it for you? Maybe there is more work from https://github.com/PX4/PX4-Autopilot/commits/pr-enable-quad-tailsitter-diff-thrust-main we can pull to improve the control.

[Jaeyoung-Lim]

Very cool push, the model looks nice! But doesn't really work in FW for me, does it for you? Maybe there is more work from https://github.com/PX4/PX4-Autopilot/commits/pr-enable-quad-tailsitter-diff-thrust-main we can pull to improve the control.

Thanks! Yes, the fixedwing attitude control still needs a bit(a lot) of tuning 😄 For some reason after the geometry changed from the previous tailsitter, it seems to be harder to tune.

[julianoes]

Switching to the advanced lift drag plugin helped a lot in getting this stable.

Screen recording:
https://drive.google.com/file/d/1oNJdV5LIlWNSMnXIyUK-sKrcVp2RqCd1/view

[Jaeyoung-Lim]

@julianoes Thanks! Might need a bit more tuning to make it nicer, but overall I think it is ready to get in

• Video: https://youtu.be/EDb019z56cA
• Log: https://review.px4.io/plot_app?log=c4430cb6-1ed8-4bcc-b9ff-ae3d1196a501

Roll rate seems to oscillate a lot in a bank

@sfuhrer @tstastny Could you have a look?

[julianoes]

@Jaeyoung-Lim wow the back transition in the video happens out nowhere, that's a bit suboptimal, although probably unrelated to this PR.

[sfuhrer]

I've STIL tested it quite extensively and proposed some tuning adaptions.

I noticed that the FW rate controller saturation logic is wrong with this model, as here we have the FW actuators in the matrix instance 0 and not 1. It results in the rate controller I being disabled in the FW flight. I'm checking what we could do against it short term.

PX4-Autopilot/src/modules/fw_rate_control/FixedwingRateControl.cpp

Line 284 in 377034d

if (_control_allocator_status_subs[_vehicle_status.is_vtol ? 1 : 0].update(&control_allocator_status)) {

[Jaeyoung-Lim]

@julianoes tailsitter SITL tests seems to be reliably failing after PX4/PX4-SITL_gazebo-classic#980

[sfuhrer]

Force pushed to remove unrelated commit and push that in a separate PR: #21592

[julianoes]

@julianoes tailsitter SITL tests seems to be reliably failing after PX4/PX4-SITL_gazebo-classic#980

I think that's funny. We should swap it to the advanced lift drag plugin. The model working before seemed pretty much nonsense.

[sfuhrer]

@julianoes tailsitter SITL tests seems to be reliably failing after PX4/PX4-SITL_gazebo-classic#980

I think that's funny. We should swap it to the advanced lift drag plugin. The model working before seemed pretty much nonsense.

I've adapted the tuning now also for the tailsitter with control surfaces, see last two commits.

[Jaeyoung-Lim]

@tstastny @sfuhrer @julianoes Anything else to address to get this in? I would rather merge it and address improvements separately

[sfuhrer]

@Jaeyoung-Lim let's resolve the conflict and get this in, I also don't see any blocker.

[Jaeyoung-Lim]

@sfuhrer Thanks! Done!