Autotune Problem

Hi all.  I posted this in the wrong forum yesterday, so I just edited it to post it to the 3.x forum.  I am hoping someone can help me out.  I appreciate any help that you can provide.  My quadcopter flies fine except for the issue noted below.  The problem I have is when I start autotune, everything goes fine until usually a minute or two in.  The quad then pitches or rolls as it normally does in autotune but it doesn't come back to horizontal and just takes off full throttle holding the pitch or roll autotune had the quad perform.  I have been lucky to recover from all of these unexpected maneuvers.  There was one time that the quad did this and flew a good 50 yards away before I was able to get control again.  I just don't know what is wrong with it.  I have never been able to complete an autotune.  It always fails after one of these maneuvers.  I was reading that there are a few things that can cause an autotune to fail.  One is flexible arms on the quad.  I tested mine and they do flex a bit, but I am not sure if it would be enough or even the reason the quad does this in autotune.  The specs for my quad are listed below.  

In stabilize, the quad flies great except when I initiate an oscillation by moving the pitch/roll stick back and forth.  The quad then goes into an oscillation that is almost unrecoverable.  The only way I can recover from it is if I lower the throttle and gently increase it.  If I give it more throttle or adjust throttle to keep the same altitude, the quad will most likely crash.  I tried re-tuning the quad but it does the same thing.

I have completed several planned missions with the quad.  I wanted to complete an autotune before putting my camera gimbal on the quad.  I am uneasy about putting it on because of the oscillations that can be induced and potentially causing a crash.  

My son took a video of the problem but he's only 5 so the video isn't all that great and didn't capture the problem the second time it happened.  You will see the quad take off to the left during auto tune but I recover quickly in the video.  

http://youtu.be/c3TMNY-Hmgs?list=UUx4C9BKl4FobHFG-ln4v-yQ

Hobbyking AQ-600 frame

Sunnysky X2216 1100KV motors

Turnigy Plush 30A ESC's

10x4.7 props

APM 2.5 with external compass

3DR uBlox GPS with compass

Arducopter firmware version 3.1.5

5000mAh 3S battery

2014-08-30 11-03-13.log

IMG_20140821_124722203_HDR (Medium).jpg

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

Join diydrones

Email me when people reply –

Replies

  • Zach,

    I will definitely let you know if I find out what the problem with my quad is. I'm just not sure what else to try. I tried looking at my logs, but interpreting them isn't the easiest thing to do. I will have to go back and see if ATDE data is included in my logs. If not, then I should probably go do anther auto tune flight with that enabled and upload it to my post. I'll try and get another video also.
    • Hi Arion,

      I had some luck yesterday with my quad. I noticed the quad would oscillate around the 1-2 axis fairly quickly, probably just under 10 Hz in a pretty unstable way. I also noticed motor (2) on my quad was angled slightly towards the center of the quad. 

      I loosened all of the arms and re-torqued the bolts while the quad was level which seemed to slightly lessen the oscillations, but the biggest difference was made when I calibrated the ESC's. Video demo here: https://www.youtube.com/watch?v=gYoknRObfOg. I would suggest giving this a try. After calibration my oscillations were gone but the quad was still 'twitchy'. No where near as bad as before and seemed to be working at a level that would allow autotune... so I tried it. Success!

      After autotune the quad flew rock solid for 3 batteries. (45 minutes).

      I'd give the ESC calibration a shot if you haven't already.

      Zach

      • Zach,

        Thank you so much man.  The ESC calibration worked!  I had zero problems after I did that.  I could not induce an oscillation when I tried stabilize.  I then tried autotune and it completed with no problems!  My quad flies perfect now.  Thanks again man.

        Arion

  • Hi Arion -

    I had a look at your video. It looks similar to what I experienced today. Let me know if you figure out what is happening and I'll do the same. 

    Another note I remember now after reading your post I only put 1 out of the 4 screws on for each of the quad legs (F450 frame) I have so it's possible there was some flex there. I could see that resulting in the instabilities I mentioned in my post but have a hard time believing it could cause the quad to power up and blast off to the left (mine was left too...) the way I saw today and you show here.

    Zach

This reply was deleted.

Activity

DIY Robocars via Twitter
May 15
DIY Robocars via Twitter
May 14
DIY Robocars via Twitter
May 13
DIY Robocars via Twitter
RT @f1tenth: Say hi to our newest #F1TENTH creation for @ieee_ras_icra next week in Philly. It’s going to be huge! 😎 🔥 @AutowareFdn @PennEn…
May 13
DIY Robocars via Twitter
May 11
DIY Robocars via Twitter
May 8
DIY Robocars via Twitter
RT @SmallpixelCar: Noticed my car zigzagged in last run. It turned out to be the grass stuck in the wheel and made the odometry less accura…
May 8
DIY Robocars via Twitter
RT @SmallpixelCar: Test my car. RTK GPS worked great. Thanks @emlid for their support. https://t.co/EkQ6qmjmWR
May 8
DIY Drones via Twitter
RT @chr1sa: @kane That's @diydrones circa 2009. Still have a box of those Canon cameras that we used to strap into planes, just like this.…
May 3
DIY Robocars via Twitter
RT @chr1sa: Our next @diyrobocars race is going to be outside at a real RC racetrack in Fremont on May 28. Fully autonomous racing, head-to…
Apr 30
DIY Robocars via Twitter
RT @f1tenth: Our Spring 2022 F1TENTH course @PennEngineers is coming to an end with a head-to-head race as a big finale. So proud of our st…
Apr 26
DIY Robocars via Twitter
RT @DanielChiaJH: I wrote a thing! Throughout the development of my @diyrobocars car I've been using @foxglovedev Studio to visualize and d…
Apr 23
DIY Robocars via Twitter
RT @SmallpixelCar: My new car for high speed. Low body, everything ( @NVIDIAEmbedded Jetson Xavier NX, @emlid RTK GPS, IMC) under the deck…
Apr 23
DIY Robocars via Twitter
Apr 21
DIY Robocars via Twitter
RT @f1tenth: F1TENTH Race training setup @PennEngineers for our upcoming ICRA2022 @ieee_ras_icra competition. @OpenRoboticsOrg @IndyAChalle…
Apr 21
DIY Robocars via Twitter
RT @fatcatFABLAB: Proud to be hosting a restarted DIY Robocars NYC Meetup April 26. Come by if you want to talk about and race self-driving…
Apr 17
More…