Low takeoff is not getting executed

[julianoes]

Describe the bug
When the takeoff altitude is set too low (< than around 0.7 meters) using the param MIS_TAKEOFF_ALT a quadcopter won't takeoff but just auto-disarm again.

To Reproduce
Steps to reproduce the behavior:

1. Start SITL jMAVSim or Gazebo
2. param set MIS_TAKEOFF_ALT 0.5
3. commander takeoff

Expected behavior
It should still take off even if the altitude is quite low.

Log Files and Screenshots
https://logs.px4.io/plot_app?log=b5802f74-4a52-42f2-8f31-0bbf01fa84e9

Additional context
This currently makes the MAVSDK integration test ActionTakeoffAndKill fail.

[julianoes]

git bisect points to bb055fd. @bresch 😭

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[julianoes]

@MaEtUgR that's what I was referring to.

[bresch]

@julianoes We changed quite a bit the waypoint tracking logic since then, could you check is this issue is still there?

[julianoes]

@bresch nice! I tested 0.5m and 0.3m which worked. 0.2m worked sometimes and 0.1m stayed on the ground but that's already much better!

The MAVSDK test used is:

build/src/integration_tests/integration_tests_runner --gtest_filter="SitlTest.ActionHoverSyncLower"

plus this diff:

diff --git a/src/integration_tests/action_hover_sync.cpp b/src/integration_tests/action_hover_sync.cpp
index 087b1650..60dee2c3 100644
--- a/src/integration_tests/action_hover_sync.cpp
+++ b/src/integration_tests/action_hover_sync.cpp
@@ -23,7 +23,7 @@ TEST_F(SitlTest, ActionHoverSyncLower)
 {
     // TODO: less than 1.0 is currently failing due to a Firmware bug.
     // https://github.com/PX4/Firmware/issues/12471
-    takeoff_and_hover_at_altitude(1.5f);
+    takeoff_and_hover_at_altitude(0.1f);
 }

[bresch]

@julianoes BTW, why is the Navigator not complaining?
MIS_TAKEOFF_ALT is the lowest altitude you should be able to go during takeoff:
https://github.com/PX4/Firmware/blob/b9fab04adbfd92783206a08364c8fea077f1ed39/src/modules/navigator/takeoff.cpp#L86-L105
Are you setting that parameter differently or are you not passing through this logic?

[julianoes]

I'm using this parameter to set the takeoff altitude before a takeoff.

https://github.com/mavlink/MAVSDK/blob/4d8d4b3836a2bc46c01b89bfd523306ef7c851a7/src/plugins/action/action_impl.cpp#L377-L383

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.