Y6 with APM2.5 Arducopter 3.1 rc5 Autotune Problem

Hi,

last week I tried autotune with my Y6 copter. With my tricopter it worked so great, that I was expecting a good result with the Y6.

At some point the copter did some strange movements and nearly crashed to the ground. I could recover it by taking over controll and did an emergency landing in a field.

Ii was very foggy that day and after the flight, the copter was pretty wet. So I thought, it could be some issue caused by the wetness.

So I did not pay to much attention to that.

Today I took out my Y6 and tried autotune again as it was dry and no wind today.

I started autotune and it began to do the rocking over roll and then over pitch. Nearly at the end of the pitch session, it became really scary. The back motors nearly stopped for several times what led to very scary movements. I had enough height and good nerves and so I let it happen. It was exactly the same as it was last week when I did autotun in foggy conditoins.

After a few of this movements, it stopped. Then I flew a few rounds, just to give the compass same data to calibrate and then landed, disarmed and switch off autotune to save the values.

Then tried the new settings and was really disappointed. the copter was terribly shaky.

At home I looked at the PID values and saw some really strange values.

I attached the PID settings before the autotune (Defaults with 3.1rc5 Y6) and after the autotune.

I also attached the logfile of that flight.

I mam just uploading the onboard video. Will link to it, when it's all up.

Hopefully someone could find out what's going wrong with this autotune.

preautotune.JPG

postautotune.JPG

2013-11-15 17-49 4.log

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

Join diydrones

Email me when people reply –

Replies

  • You probably have the answer to this already, but you can search for "autotune esc sync issues" to find a complete explanation of the issue.  Also the Marco Robustini sync problem video at https://www.youtube.com/watch?v=0lRTN5o4UCM

    Best

    Richard

    • Developer

      Hi Richard,

      Thanks for offering help here but this isn't the esc sync issue. This is the large flexible mass issue with autotune.

      • OK thanks Leonard, I saw his initial comments about some motors nearly stopping.  But yes there looks like a lot of compliance between the airframe and the extended mass of LiPo/Camera based on the photos/video.  Thanks again. Richard

  • Developer

    Hi Arbo,

    I don't see new discussion posts but I do reply to any autotune questions on the latest release thread. That is how I found your post from 9 hours ago (about when I went to bed last night). I am also a single father with 2 children under 3 years old and my hobby has to come second. So you will have to forgive me for the delay in answering your question.

    You are correct that Autotune has not worked for on your frame. I have seen this problem before and I believe it is caused by an overly flexible frame or overly soft vibration isolation on your APM. I would suggest that you see if you can move the arms or any of the center plates and check that the APM feels solid in the way it is mounted.

    Other issues that can mess up Autotune is an incorrect CG,  props being too large for the motor and battery combination, and letting the copter build up too much airspeed during the test.

    If you post some photos of your frame here I may be able to make other suggestions.

    Now that I have replied to your post I should get an email when you reply.

  • No idea?

  • Here is the onboard video.

This reply was deleted.

Activity

DIY Robocars via Twitter
RT @TinkerGen_: "The Tinkergen MARK ($199) is my new favorite starter robocar. It’s got everything — computer vision, deep learning, sensor…
Nov 23
DIY Robocars via Twitter
Nov 23
DIY Robocars via Twitter
RT @roboton_io: Join our FREE Sumo Competition 🤖🏆 👉 https://roboton.io/ranking/vsc2020 #sumo #robot #edtech #competition #games4ed https://t.co/WOx…
Nov 16
DIY Drones via Twitter
First impressions of Tinkergen MARK robocar https://ift.tt/36IeZHc
Nov 16
DIY Robocars via Twitter
Our review of the @TinkerGen_ MARK robocar, which is the best on the market right now https://diyrobocars.com/2020/11/15/first-impressions-of-tinkergen-mark-robocar/ https://t.co/ENIlU5SfZ2
Nov 15
DIY Robocars via Twitter
RT @Ingmar_Stapel: I have now explained the OpenBot project in great detail on my blog with 12 articles step by step. I hope you enjoy read…
Nov 15
DIY Robocars via Twitter
RT @DAVGtech: This is a must attend. Click the link, follow link to read the story, sign up. #chaos2020 #digitalconnection #digitalworld ht…
Nov 15
DIY Robocars via Twitter
RT @a1k0n: Got a new chassis for outdoor races (hobbyking Quantum Vandal) but I totally didn't expect that it might cause problems for my g…
Nov 11
DIY Drones via Twitter
First impressions of the Intel OpenBot https://ift.tt/36qkVV4
Nov 10
DIY Robocars via Twitter
Nov 9
DIY Robocars via Twitter
Excellent use of cardboard instead of 3D printing! https://twitter.com/Ingmar_Stapel/status/1324960595318333441
Nov 7
DIY Robocars via Twitter
RT @chr1sa: We've got a record 50 teams competing in this month's @DIYRobocars @donkey_car virtual AI car race. Starting today at 10:00am…
Nov 7
DIY Robocars via Twitter
Nov 6
DIY Robocars via Twitter
RT @a1k0n: Car's view, using a fisheye camera. The ceiling light tracking algorithm gave me some ideas to improve ConeSLAM, and having grou…
Nov 5
DIY Robocars via Twitter
RT @a1k0n: To get ground truth I measured the rug, found the pixel coordinates of its corners, calibrated my phone camera with my standard…
Nov 5
DIY Robocars via Twitter
RT @a1k0n: @DIYRobocars is back in December, but outside. Time to reinvestigate ConeSLAM! I rigged up a quick and dirty ground-truth captur…
Nov 5
More…