Pixhawk problems with new airframe.

I recently switched airframes from a "Plus" configuration to "X".  I had previously had intermittent problems with "Bad Accel Health", but never untoward events.  With the change to the X configuration on a Cinetank, I cannot get my copter off the ground after checking correct motor orientation, layout, and multiple calibrations.  I wonder if this is at all related to the accel issues I had previously experienced with my Pixhawk (HK Pilot)

Attached is a log from a test from this evening. During the test, I armed the copter while holding it and ran the throttle up.  The motors would not balance in terms of force unless the copter was at a 45 degree roll to the right, despite the artificial horizon being accurate on APM planner.  I also noted that my motor 2 and 3 servo outputs were consistently higher than motors 1 and 2 once the throttle was placed above minimum.  Hard RC input roll via transmitter seemed to slow the port side motors to be equal to the starboard motors.  It almost seems that the flight controller responds as if it thinks it is tilted left (despite the artificial horizon demonstrating correct orientation)

I would appreciate any advice or insight you could offer.

Is this a fatal hardware error, if so, I am going to purchase an official 3DR Pixhawk.  I just don't want to buy another only to find that it was something related to software setup.

Thanks,

25.BIN

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  • Looks your roll and des roll, is like your copter couldn't do what the controller it's saying to do, it's common issue with harware problem, an arm twisted, incorrect connections esc fail, prop incorrect, etc,

    3701993132?profile=original

    • So, after more thought and investigation, I think this turns out to be an issue with the RCMAP function (or rather dysfunction) in arducopter 3.2.1.  Looks like it is being addressed in 3.3.  Thanks for your help

    • Thanks for looking.  Now that I think about this log some more, Des Roll is 20 when I am holding the copter level with my hand, which it should not be...it should be 0 (since level).  It is as if the copter is trying to fight to stay level, but that the reference for level is off.  I have calibrated a number of times, so I suspect it is an instrumentation issue, and it is time for a new PixHawk.  Will order one and see if that fixes the issue.  Thank you for your assistance.

      Rob
  • Looking your logs its sounds like a harware problem, do the following:

    On the floor:

    Are props on the correct position as instructions indicates?

    Looks here what Richard do to fly the first time if usefull for you http://diydrones.com/group/pixhawk/forum/topics/no-right-yaw-after-...

    • Thank you so much for looking.  

      I have re-calibrated multiple times.  Motor test confirms all motors spin in correct position and ESCs attached in the correct order.

      When doing the "Hand Test", all motors respond appropriately to input from the radio, BUT, the drone wants to find a neutral position at a 30-45 degree angle to the right.When held in this position, the port and starboard motors attempt to maintain this 30-45 degree right roll angle continuously.  Pitch works the way it should.  If I physically try to roll the copter left from that 45 degree angle, the port motors increase speed to maintain the 45 degree right roll.  Alternately, if I roll the copter by hand to 50-50 degrees to right, the starboard engines increase speed to get it back to the 45 degree roll angle.

      Here is the weird part though...The artificial horizon in Mission Planner reports the correct roll angle of the copter. It is as if some other IMU (from the one reported in Mission Planner) is determining that the roll angle of the copter is not correct...Is this possible.

      I will send a picture of the quad when i get home.

      Thanks, 

      • can you share the log of that test? and if you have tlog, too, better, I have APM but your imus looks well up where I understand, I think that you have a problem on your hardware that, when motors try to do what it's suposse to correct position, they can't

        • Here is the dataflash log from repeat of this test this afternoon.  I did not wait to get GPS lock and kept in stabilize mode.  I don't have a tlog, but I can keep mission planner on next time I do the test.

          Thank you for looking at this for me. I really appreciate it.

          2015-05-02 17-50-06 10.bin

  • It sounds that a calibrate problem? can you share a photo from your copter? It's first fly? or a connection issue?

  • Can nobody help me with this?  The multicopter with the "Hand Test" reacts appropriately when rolled approx 40 degrees to the right and it does everything it can to hold that position.  All I am asking is for someone else to confirm my suspicion that this is a hardware problem with my HK Pixhawk.  If you concur, I am going to order the real deal from 3DR tonight....I am done with clones when the 3dr product is so well supported

    Thanks,

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