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Octo X8 Coaxial - testing motor redundancy

Posted by Bernardo M. A. on August 7, 2013 at 3:30am

Testing the octo without 1 of the top motors and then 1 of them bottom motors to check what's happens if a prop/motor/esc gets bad during flight.

Previously I've done the same test with a flat hexacopter and an Y6 but they didn't performed very well.

With a flat octocopter, if it looses 1 motor/esc/prop it's barely affected. I was flying my octo and it lost a blade of a prop but I just noticed after I landed.

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Comments

  • Vince Hogg August 9, 2013 at 7:01am

    Bernardo.

    Thanks for experiment, its interesting to see. Not many people are testing with a motor failed.

    I have been designing a new copter and nearly went for x8 but was concerned a lower failed prop might windmill and cause drag. Im glad I went for flat octa.

     

    I think it would be possible to write much more motor failure tolerant code (perhaps not on APM). I think it may even be possible gently descend a quad with a failed motor if it was yawed very rapidly to stop it from flipping.

  • Boris Rabusic August 8, 2013 at 12:29am

    eduardo, great, if your adaptive stabilization is better then one in arducopter please share it with arducopter developers

  • Bernardo M. A. August 7, 2013 at 3:12pm

    Very nice eduardo ;)

    I've already done that with MegaPirateNG using a flat hexa and I couldn't take off although it had been hovering with half throttle stick. (I didn't modify the hexa, just disconnected the ESC cable)

    When I tried the Y6, it worked partly. I could take off only when specific motors were disconnected.

  • eduardo August 7, 2013 at 2:03pm

    Boris, i do more tests with camera and gimbal and 10amp battery on the same frame and it fly very good.

    Some time i am fly 500m away and when i land i see that the hexa is flying without one prop.

    As you can see this is an very old video. I do this video when i testing my adaptive code. Its only to test the code.

    I do the same test with other motor OFF.

    BTW, i not removed the ARM ... it broken

  • Boris Rabusic August 7, 2013 at 1:32pm

    eduardo, 

    it's not actual test since you removed one arm and motor, plus you put one battery to be counter weight on opposite motor.

    Real test is to do it:

    -in midflight (using remote switch for pwm signal)

    -with full load

    That is real world test.

    I've done it on Naza with hexa and flat octa.

    When fully loaded (5 kg), hexa will land, but not so much controllable. Octa is ok.

  • eduardo August 7, 2013 at 12:49pm

    Here are a test with my own rotorcraft controller using ADAPTIVE STABILIZATION.

    http://vimeo.com/14367712

    As you can see it fly perfect without one arm.

    Try this with arducopter and you see that it not work good because ACM not use adaptive stabilization.

This reply was deleted.