[macphyter]

I've got my quad running the GPS modes pretty well now.  PositionHold is working, Return to Base works great, and the auto-landing is AMAZING to watch, I love it.  However, I can't seem to get the auto-takeoff to work correctly.  Here's my procedure:

-I flip the switch to put it into the auto-takeoff flight mode
-Then I arm it
-Next I move the throttle up to 50%

When I do this, the props start to spin up, and then it tries to lift off, but it starts tilting at a strange angle right away.  As the angle gets steeper and steeper, it eventually hits the emergency cutoff angle of 25 degrees, and the motors stop.  I've been tweaking settings, but nothing seems to help.  Any idea what I'm missing here?

Thanks.
  -Macphyter

[jdl]

Just an idea, not sure if can be applicable in your case:

Look in System / VtolPathFollowerSettings / YawControl. Set it to Manual! I had unpleasant expirience when testing fully autonomous flight with preset plan including AutoTakeOff as first step. When YawControl is not Manual, and the next POI is not exactly above the takeoff location, the FC attempts to point the nose of the vehicle in the desired direction (MovementDirection, PathDirection, etc.) immediately during takeoff. That causes an ugly tilt and possibly - a crash.

P.S. Thinking again, that tilt I decribed might be caused just by the big distance from the takeoff position of the next waypoint in the flight plan. And second: when I performed the test the quad had slow ESCs - no OneShot125, no DampedLight. They made the frame behave "imprecise" with rapid yaws, so AutoTakeOff combined with YawControl = PathDirection and distant next WP led to the tilt I observed.

[f5soh]

Generally a banking quad while take off in Ins13 is due to a Mag disturbed or that need a better calibration.
You should see the same the same banking take off in manual/Attitude mode.
Post your config file for calibrations. File > Export UAV Settings

[macphyter]

jdl-  Thanks for your suggestion.  I'm not using flight plan yet, I'm just trying to initiate an auto takeoff and I assume it will hover at the preset altitude until I switch flight modes.  I checked my yaw control, and it IS set to manual, but if it's trying to yaw on takeoff that would explain the tilt.  Maybe I'll try some of the other yaw settings and see if that affects it.

f5soh-  In manual/attitude mode I don't think I'm seeing any banking on takeoff, but I'll go back and check.  This could be a magnetometer issue I suppose, I'll try to get my mag calibrated better and see if that helps.  Thanks.

[macphyter]

Oh, and here is my config file if that helps anything.

[f5soh]

I doubt this one do autotakeoff

No mags calibrated, complementary.

[macphyter]

f5soh-  Darn it!  I posted the wrong file, I'm sorry.  I'll go download a new one and post it.  Sorry to waste your time.

[macphyter]

OK, I got the real uav file from that quad that isn't doing the auto-takeoff.  Here it is.

[f5soh]

Try to redo the Mag calibration, scales are a little asymmetric. You can do a "Mag dance" while using Oplink:


You can also  calibrate the accelerometers.
https://librepilot.atlassian.net/wiki/display/LPDOC/Sensor+calibration

[macphyter]

I wasn't happy with my magnetometer calibration, so I replaced the whole thing with a DJI GPS/mag module.  I went through the calibration procedure, and it seems to be pretty solid.  I flew in velocity roam, and it worked very well, even more steady than before, and auto-land works great.  BUT, I'm still having the same problem with auto-takeoff.

Once I initiate the takeoff sequence, it starts tilting to one side, and it never gets enough throttle to lift off the ground.  I adjusted the board level calibration to make sure it was truly level.  I tried setting it up on a cardboard box which allows it to yaw, and that doesn't change anything.  If I manually send a yaw command while in this mode, it jumps slightly and then settles back down to the ground.  It just isn't getting enough throttle to take off.

I can switch to velocity roam on the ground, and then increase throttle until it takes off, and that seems to work pretty well.  I feel like I'm just missing some setting that will allow the auto-takeoff to work.  I've attached my most recent UAV config file, along with a log captured while trying takeoff mode.  Maybe someone will see something I'm missing?  Thanks.

[f5soh]

Maybe redo the Accel calibration, i doubt the result could be so asymmetrical:

Code: [Select]

0.871595442,1.0011605,0.985316098

[macphyter]

Maybe redo the Accel calibration, i doubt the result could be so asymmetrical:

Code: [Select]

0.871595442,1.0011605,0.985316098

OK, that sounds like good advice.  How close should I expect those numbers to be, in order to be considered "symmetrical"?
 

[TheOtherCliff]

Yours varies by about 13%.  My worst varies by about 2%.

Code: [Select]

$ grep -i accel_s ../settings/*
../settings/2016-05-29 Revo3 autotune3.uav:    <field name="accel_scale" values="0.994404972,1.00742996,0.981265008"/>
../settings/2016-09-22 Sparky23 final.uav:     <field name="accel_scale" values="0.999965131,1.00079167,0.995214462"/>