Tower and Yaw

[Ed Beck]

Does anyone KNOW how the Yaw parameter in Tower works?

I've just spent the afternoon flying in squares setting the yaw parameter to different settings and I have no clue how it's figuring out which way to point the nose. I brought my little notepad and took lots of notes, and have no idea how the yaw parameter actually affected Solo. Even worse the results were not entirely repeatable.

Please - I'm not asking for what the manual says, or what sounds right, but from someone who has used the yaw setting under a variety of conditions and absolutely knows how it works.

 

[5r49cfu]

+1 would like to hear about this too

 

[Ed Beck]

If anyone is out testing I thought of trying something next time. I wonder what would happen if you set the yaw to zero after arriving at a waypoint and then setting it to something else. This is just a guess based on nothing in particular, just wondering if yaw is relative to the last yaw setting.

 

[5r49cfu]

I have been testing the Yaw setting in Tower.

It seems that a Yaw setting is only valid until the next waypoint. Once you reach that new waypoint, the camera points in direction of travel.

NOTE that sometimes the Yaw setting is skipped! Not repeatable.

Does anyone have any experience with Yaw and can share tricks to make sure it is not skipped?

 

[Ed Beck]

The only thing I've found to be repeatable is if the "Relative" box is unchecked yaw will point Solo towards (probably) the true direction.

For example if yaw is set to 90 and the relative box unchecked Solo will point east. I say "probably" because I'm not positive it it is magnetic or true direction, I'm pretty sure it's true.

 

[Ed Beck]

I've also tried to set a relative yaw point after each waypoint with inconclusive results.

 

[Ed Beck]

Looking at the parameters I also found this relating to yaw:
COMPASS_USE - Enable or disable the use of compass (instead of GPS) for determining heading.
Default = 1:Enabled

So I guess that means it will point to magnetic directions with the relative box unchecked.

 

[Pedals2Paddles]

It sets the yaw relative to the current heading. And it's executing that command when it it hits the prior waypoint. So what may be happening is the copter is turning at the waypoint to face the next waypoint. And at the same time, the Set Yaw command fires. So it will set the yaw relative to whatever direction it was pointing at the time while it was already turning. The result will be the nose pointing in a random direction you weren't looking for.

What you need it to do is execute the Set Yaw command after it has established on course to the next waypoint. In Mission Planner, there is a command called Condition_Delay, measured in seconds or distance. You put that between the prior waypoint and the yaw command. (btw, "set yaw" is actually called "Condition_Yaw" in arducopter and Mission Planner). So it might look like this:

Waypoint 1
Waypoint 2
Waypoint 3
Condition_Delay (4 seconds) [lets it establish on course to WP4
Condition Yaw (20 degrees rel) [turns to face relative to current heading.]
Waypoint 4
Waypoint 5
Etc

Also, you'll notice it resets to face along the flight plan path every time you pass another waypoint. If you want it to not do that, you would need to change the parameter WP_YAW_BEHAVIOR to 0. With it set for 0, the copter will stay pointing in the same direction throughout the mission. You can adjust it with the yaw stick. Or you can adjust it with Conition_Yaw ("Set Yaw") commands.

0 Never change yaw
1 Face next waypoint
2 Face next waypoint except RTL
3 Face along GPS course