Loiter / Auto - Yaw spinning on takeoff - Discussions

I have made some good progress on my Vario project. I was able to get vibrations, and mag issues resolved and Loiter performance to an acceptable level. I noticed something though, sometimes while taking off in Loiter the heli will spin around anywhere from 45 to 540+ degrees upon liftoff. I read somewhere that this is a known issue with the heading resetting after takeoff due to mag fields in the ground? Aware of this issue I decided to do a few Auto flights anyway and saw the same behavior. It is random an unpredictable.

In Auto, however I was able to do a few successful flights with no in-flight issues.

Also, in Auto while having "Land" set to my last waypoint the heli does not disarm after touchdown. In LAND mode (not Auto) it does and if using RTL as the final waypoint it will disarm. Just wondering why it doesnt disarm in Auto-Land?

If anyone has any thoughts on this I would greatly appreciate it.

I cannot attach the logs from the flights because the files are too big as it was powered on for over minutes! If someone wants them I can send a link from dropbox or something.

Chris

I have a lot of flight time on my setup now and have been using the Left yaw input to get the tail straight for takeoff after arming. I am curious as to if there was an update to 3.2.1 to fix this? I recently got a new Pixhawk and loaded the firmware and got it flying and I am seeing a difference in this Armed Yaw issue. Basically now, after arming if I dont do anything the heli will spin to the right on takeoff even thought the tail appears to be straight... if I hold left yaw for the same amount of time as I did right yaw for the arming process, the heli will then spin left upon take off... if I just give a quick left rudder pulse, the tail blades remain straight and it takes off straight...

I was also wondering if the Reset to Armed Yaw function could be utilized on Ch7. to take out the guess work on this?

Thanks,

Chris

Replies

Chris Maier October 2, 2015 at 10:07am

I have a lot of flight time on my setup now and have been using the Left yaw input to get the tail straight for takeoff after arming. I am curious as to if there was an update to 3.2.1 to fix this? I recently got a new Pixhawk and loaded the firmware and got it flying and I am seeing a difference in this Armed Yaw issue. Basically now, after arming if I dont do anything the heli will spin to the right on takeoff even thought the tail appears to be straight... if I hold left yaw for the same amount of time as I did right yaw for the arming process, the heli will then spin left upon take off... if I just give a quick left rudder pulse, the tail blades remain straight and it takes off straight...

I was also wondering if the Reset to Armed Yaw function could be utilized on Ch7. to take out the guess work on this?

Thanks,

Chris
- Rob_Lefebvre > Chris Maier October 3, 2015 at 4:08am
  
  Hi Chris, this issue is resolved with 3.3 which should be going stable soon. So if you just wait a little while longer and then use that release, your problem should be resolved.
Rob_Lefebvre July 1, 2015 at 11:23am

Hi Chris, which firmware are you using?

I'm going to guess, the yaw on take-off is always to the right? Is that correct?

I believe I know what the issue is and hope to fix it soon.

I don't think it's the mag heading issue, which has already been fixed. That would result in a sharp yaw movement after climbing 1m, then again at 5m. But not immediately on lift-off.

The yaw to the right immediately on lift-off, is due to the system registering a right yaw request as you are moving the yaw stick right to do the arming. I need to add something so that it ignores this stick input during arming.
- Chris Maier > Rob_Lefebvre July 1, 2015 at 12:21pm
  
  Rob, thanks for the quick reply.
  
  I am running 3.2.1.
  
  Yes, the yaw only happens to the right and now I can understand why.
  
  Would simply holding left rudder after Arming for the same amount of time fix this?
  
  Also, if there is a fix for this, when will it be released?
  
  Thanks!
  - Rob_Lefebvre > Chris Maier July 7, 2015 at 5:01am
    
    I'm planning on fixing this for 3.3.
    
    Yes, you can sort of fix it if you push a bit of left rudder until you see the tail rotor blades go straight. Then it should take off relatively straight.
    - Chris Maier > Rob_Lefebvre July 20, 2015 at 5:57am
      
      I have been using the left yaw method to counteract the arming yaw and the heli takes off pretty straight.
      
      Is there an ETA on 3.3?
    - Chris Maier > Rob_Lefebvre July 7, 2015 at 6:47am
      
      Arming from MP would be a nice fix to this too.
      
      When is the estimated release date for 3.3?

This reply was deleted.