Unexpected yaw

I'm having an issue where the copter frequently yaws unexpectedly.  I believe the copter is accurately controlling it's yaw, so the yaw movement is being generated somewhere within the control system.  I've checked that my RC Rudder input is centered, and I've checked (though it seems like this is still the most likely problem) that my compass orientation is correct.

Can anyone take a look at my log files and figure out what's going on?  I've attached log files of two flights where this issue occurred.

Here's an image showing centered RC Rudder input, but both desired yaw and actual yaw moving steadily (towards the end of the graph):

3691301424?profile=original

The copter is built so that the Pixhawk is right-side-up but facing the back of the copter.  The GPS/Mag is also right-side-up but facing the back of the copter.  I'm running the 3.3.4 beta, but I've had the same issue with 3.3.3.

Uncommanded Yaw 1.bin

33 6-5-2016 4-57-36 PM.bin

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • Could you solve the problem?

    I had almost the same. My pixhawk decided to do a random hard yaw movement.

    http://diydrones.com/m/discussion?id=705844%3ATopic%3A2270298
    • I finally figured it out, and (perhaps not surprisingly) it wasn't APMs fault, but a slightly loose motor mount that would rotate sideways in flight (only slightly though, so they still made enough lift not to crash the copter).  

      There was a clue in the log - the target yaw was lagging behind the actual yaw by 10 degrees.  APM makes sure that in most flight modes the target yaw is clamped to within 10 degrees of the actual yaw, so in my case the actual yaw was "pulling" the target yaw along with it as it spun.

      I am having an different problem now that I'm pretty sure is software-based, but I'm going to a separate post about that after studying the logs some more.

  • Plot your RCOU.Ch1-4 

    You will see something is very wrong, yes, as you lose yaw, motors 3,4 are very low, but the same happens around log line 91000 - without mych yawing.   (that should not be possible)

    Something is not performing correctly. While at hover, you should expect all 4 motors to be at about the same thrust setting, and unless yawing, 1,2 or 3,4 should not be far from each other.

    Screenshot from 2016-06-06 23-15-31.png

    https://storage.ning.com/topology/rest/1.0/file/get/3702251083?profile=original
This reply was deleted.

Activity

DIY Robocars via Twitter
How to use the new @donkey_car graphical UI to edit driving data for better training https://www.youtube.com/watch?v=J5-zHNeNebQ
13 hours ago
DIY Robocars via Twitter
RT @SmallpixelCar: Wrote a program to find the light positions at @circuitlaunch. Here is the hypothesis of the light locations updating ba…
Saturday
DIY Robocars via Twitter
RT @SmallpixelCar: Broke my @HokuyoUsa Lidar today. Luckily the non-cone localization, based on @a1k0n LightSLAM idea, works. It will help…
Thursday
DIY Robocars via Twitter
@gclue_akira CC @NVIDIAEmbedded
Wednesday
DIY Robocars via Twitter
RT @luxonis: OAK-D PoE Autonomous Vehicle (Courtesy of zonyl in our Discord: https://discord.gg/EPsZHkg9Nx) https://t.co/PNDewvJdrb
Wednesday
DIY Robocars via Twitter
RT @f1tenth: It is getting dark and rainy on the F1TENTH racetrack in the @LGSVLSimulator. Testing out the new flood lights for the racetra…
Wednesday
DIY Robocars via Twitter
RT @JoeSpeeds: Live Now! Alex of @IndyAChallenge winning @TU_Muenchen team talking about their racing strategy and open source @OpenRobotic…
Nov 20
DIY Robocars via Twitter
RT @DAVGtech: Live NOW! Alexander Wischnewski of Indy Autonomous Challenge winning TUM team talking racing @diyrobocars @Heavy02011 @Ottawa…
Nov 20
DIY Robocars via Twitter
Incredible training performance with Donkeycar https://www.youtube.com/watch?v=9yy7ASttw04
Nov 9
DIY Robocars via Twitter
RT @JoeSpeeds: Sat Nov 6 Virtual DonkeyCar (and other cars, too) Race. So bring any car? @diyrobocars @IndyAChallenge https://t.co/nZQTff5…
Oct 31
DIY Robocars via Twitter
RT @JoeSpeeds: @chr1sa awesomely scary to see in person as our $1M robot almost clipped the walls as it spun at 140mph. But it was also awe…
Oct 29
DIY Robocars via Twitter
RT @chr1sa: Hey, @a1k0n's amazing "localize by the ceiling lights" @diyrobocars made @hackaday! It's consistently been the fastest in our…
Oct 25
DIY Robocars via Twitter
RT @IMS: It’s only fitting that @BostonDynamics Spot is waving the green flag for today’s @IndyAChallenge! Watch LIVE 👉 https://t.co/NtKnO…
Oct 23
DIY Robocars via Twitter
RT @IndyAChallenge: Congratulations to @TU_Muenchen the winners of the historic @IndyAChallenge and $1M. The first autonomous racecar comp…
Oct 23
DIY Robocars via Twitter
RT @JoeSpeeds: 🏎@TU_Muenchen #ROS 2 @EclipseCyclone #DDS #Zenoh 137mph. Saturday 10am EDT @IndyAChallenge @Twitch http://indyautonomouschallenge.com/stream
Oct 23
DIY Robocars via Twitter
RT @DAVGtech: Another incident: https://t.co/G1pTxQug6B
Oct 23
More…