Waypoints and yaw behaviour

ArduCopter Copter 3.6
1

I’ve experienced unexpected yaw behaviour when flying the same path a 2nd time. The parameter
WP_YAW_BEHAVIOR is set to 3 in both cases but in the 2nd try the copter just didn’t steer yaw in the flying direction but let me steer.
I also tried to set ROIs but it’s the same issue. Any idea what could be the reason or what to look at?

Cheers

2

just to be sure I looked at the RC inputs and RC4 (yaw) is showing 1499 when starting Auto flight mode. As the copter direction didn’t align with the flight path I started to steer manually at 55:20 and again at 55:27:

yaw not behaving
yaw not behaving2408×1136 267 KB

these parameters I suspected:
WP_YAW_BEHAVIOR 3
RC4_DZ 10
so to me they look fine, but what prevents the copter from facing along GPS path automatically?

3

Maybe try plotting ATT.Yaw and ATT.DesYaw see if there is a difference.
Also feel free to post your log file.

4

here is the graph of desired and current yaw. Looks pretty much in phase:

2020-05-09 10-54-56_yaw not behaving3
2020-05-09 10-54-56_yaw not behaving32282×956 72.8 KB

from my understanding the copter should yaw to the direction of flight as soon as the mode is changed to “auto” when WP_YAW_BEHAVIOR=3 is set. But here it’s building up speed to go to the next waypoint without the nose pointing there. After 2 seconds I’m steering manually yaw where I wanted it to be automatically.
When reaching the next waypoint (3) the hope to turn automatically was destroyed again :disappointed_relieved:

*in the diagram RC4 is yaw, it’s scaled by 5 to have a better fit to the other values on the axis