FW: Wrong yaw setpoint during climbout after handlaunch in mission mode

[fredowski]

I used firmware version 1.7.3 for flying an X-UAV Mini Talon in mission mode with hand launch. I tried to analyze some strange roll behavior during takeoff which I did not understand. I analyzed the logfile and found some very strange yaw setpoint behaviour which results in 15° maximum roll setpoint during climbout. After the climbout mode is left at 40m altitude the obviously correct yaw setpoint is computed. I guess the wrong yaw setpoint during climbout is computed with respect to the launch point.

Flight Review: https://review.px4.io/plot_app?log=b35b3054-ca70-4e56-ad30-206b863e9f83
Youtube takeoff camera 1: https://youtu.be/kpTj9TMslAM
Youtube takeoff camera 2: https://youtu.be/X1NRNYEkSco?t=282

I analyzed the log with flighplot. Image 1 shows the relevant part during climbout.

Image 1: Climbout yaw behaviour

I expect that during takeoff the yaw setpoint is computed from the takeoff waypoint.

I think that there is a problem with the mag initial heading because there is a 35° correction directly after launch. However the problem I describe here seems not to be affected from this because the yaw estimation is corrected afterward. I think the initial left roll is due to the wrong heading estimation but the following 15° maximum roll in the other direction is due to the wrong yaw setpoint.

I did not find a yaw and climbout related issue and I tried to compare the current git master vs. the 1.7.3 code to check if there might already be a fix. The current master has the takeoff code rearranged, so I am not sure. From what I see it seems to be the same.

[fredowski]

I think I found the problem... The takeoff waypoint is only about 60m away from the launch point and the takeoff point is passed at 1:09:50 before the altitude was reached. It seems that during climbout the next waypoint is not selected - so the update happens when climbout is finished. I guess this does not happen when the takeoff waypoint is sufficiently far away such that the climbout is finished before the takeoff waypoint is reached.