Vibe Xok Ybad IMU problem

Hi Group, 

(Quad Tarot 650S, Motor-4114, Prop 15.5

PixHawk FC FW333, Batt 6S, Atun Success, MP 1.3.37)

I have had this problem where plotting the Vibes Graph in MP I find that the X-axis appears ok,

whilst the Y-axis is 'way' diff to X.

I have inspected the rig to check for bad mechanics, all seems good.

Used diff sets of props of which I correct the balance, imho

I am not experienced enough to eval the problem, I hope that within the community to find info

to assist resolving the perceived problem.

I have attached the bin file here for review as well as the various pics and Atun params.

When plotting the Des/Att Pitch & Roll, it appears to me the Att P&R follows the Des P&R

closely? Although I observe in Att P&R what appears to be a continuous ~sinus-curve as it

tracks the Des P&R.  Not sure is this is normal or acceptable?

The craft flies 'ok', however, since this is actually the first time for me in the uav tech,

I admit I am not experienced enough to evaluate the craft's 'practical' in the air

flight dynamics and performance.  Although, in STBLZ mode it is quite 'agail' and 'responsive'.

In AltH and PosH it 'appears' to be good, as I understand it. 

I am though concerned about the Vibes, I don't believe it is correct and may bite me on the 'bum' in the future if not sorted.

Lastly, note that I am not an experienced pilot at all.

I appreciate any feedback or pointers to help me resolve this, if possible.

Thank you for your time.

Regards,

Gerhard

Cape Town, South Africa

3691297686?profile=original3691297441?profile=original3691297629?profile=original3691297695?profile=original

2016-05-13 16-28-40.bin

J1023.rar

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

Join diydrones

Email me when people reply –

Replies

  • Hi,

    You do have too much Y vibrations, look at the graph.
     The controller do need good damping before any other tests.

    3702242186?profile=original

    regards!

    • Hi Vesselin,

      Thank you for your reply.

      I understand that the Y-axis is bad.

      Besides mech and the mounting of the FC, could there be any other reason why the Y-ax is

      so much way-out, compared to the X-ax.  From my limited understanding, the X-ax looks 'ok'

      particularly if viewed with the 333 vibe option?  Further, it appears that both IMU(1) and 2 exhibit

      the same plotted params? Thus my conclusion that it is not a case of that IMU(1) is 'faulty',  that

      the error lies then within the mechanics of the craft or indeed the FC mounting,

      and not electronics, as in the FC itself ?

      Historicallly, I had good 'Vibe' plots prior to this, hence my concern.

       I did not modify or change the mounting of the FC.

      Could a 'bad' autoTune result in what I have now?

      Are there any other params that you can see, with your insight, in the .bin file

      that could result in the Y-axis being 'off' or any other config/result issues in general?

      What other mechanical issues, besides FC mounting, may result in this bad Y-ax vibration, typically?

      Is it possible  to record/plot individual motor vibrations?

         If so, then how do one do it?

      In the mean time I will inspect and attempt to re-mount the FC

      btw - in order for me to understand which is X/Y axis on my craft,

      can you please advise from the pasted picture, hereunder, is the correct Axis orientation? 

       I am of the opinion that is  A?  Am I right to say X=Roll('Left-Right')  and Y=Pitch('Fwd,Bwd')

      Thank you for your valued feedback and education in this most interesting technology.

      Gerhard

      3702632738?profile=original

      • Check for wires that might vibrate against the flight controller. Check for anything that can have side to side (y axis) movement, but not forward/back. Perhaps an antenna, gps pole? I had a similar problem and ended up being a torroid ring that was vibrating against a tube.

      • Hi,

        Here is link that may help: http://ardupilot.org/copter/docs/common-vibration-damping.html

        The sensors orientations are there.

        3702744687?profile=original So standard (0 = No rotation) X is front/back, and Y is left/right direction.

        Too aggressive PIDs can cause more vibrations, but in this particular case the damping is not working in Y direction, it is constant, not depending of the movements.

        If you send some pictures of the controller installation, will be easier to help you.

        Regards

        PS In most non-symmetrical frames the autotune is not working well, so I can suggest manual tune, starting from the default params.

        Vibration Damping — Copter documentation
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…
Monday
DIY Robocars via Twitter
Monday
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…