Quadcopter not performing after Autotune

Issue:

  1. Conducted Autotune couple of times and the gains are similar most of the time. Aircraft doesn’t seem to be stable at all. Can one of you please take a look at the attached logs and comment about stability of this tune?
  2. During pitch action - “Error compass Variance Warning” occurs every time . Should I worry about it?

Aircraft Details

  1. Weight: 6Kg
  2. Propulsion system: MN7005-230Kv | 24inch (Brand: T-motor) | 40A Alpha ESC
  3. CoG : Symetric about X&Y . CoG very close to propeller plane.
  4. Autopilot & GPS are at an offset with each other and the CoG - Values can be picked from the attached log
  5. Battery : 6S6P LiIon - 2.7Kg at the centre - on top of the centre cage
  6. Autopilot - Cube Orange : FW: 4.2.2 : GPS Single- Here 3
  7. All power electronics are away from the autopilot and GPS - At least 20cm away.

log attachment
https://drive.google.com/file/d/1VIGUmaJtD3B0DwZWpLKI7l0EGELyJ8F2/view?usp=sharing

1st set these to see if it helps the pitch demand oscillation
PSC_ACCZ_I
PSC_ACCZ_P

Yes, it will be a problem. Try the above 1st but in general use Magfit to calibrate the compass and produce the Motor Compensation coefficients.

Also, enable batch logging again and set the option to 4 so we can see how well the Notch filter is working.

Some of this echos what Dave already said.

Definitely upgrade to latest stable firmware right away, 4.3.2, there’s some important fixes.

Z axis vibrations are a little high, mostly on the non-damped 3rd IMU. See if you can improve the flight controller mounting and do anything else to reduce vibrations.

I would set
ATC_THR_MIX_MAN,0.5
BATT_FS_CRT_ACT,1
MOT_PWM_MIN,1100 ← these to suit the T-Motor Flame
MOT_PWM_MAX,1940
MOT_SPIN_MIN,0.13 ← might have been a bit high, we can check in next logs after the other changes
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,4

Based on your prop size I think you’ve picked up on the first harmonic instead of the primary frequency, next flights will tell us for sure
INS_HNTCH_FREQ,68
but you could safely set it to 34 anyway
and probably
INS_HNTCH_HMNCS,3
based on past experience with these larger props.

See compass settings below. Since you had some good amount of yaw in that log, I ran it through magfit.
That should sort it out.

Do a test flight in AltHold with some gentle pitch, roll and yaw. Let’s see that log.
Autotune will need to be redone after some of the changes I list above (MOT_PWM) but lets wait until we refine some more parameters.

COMPASS_DIA_X,1.000
COMPASS_DIA_Y,1.046
COMPASS_DIA_Z,0.905
COMPASS_DIA2_X,0.951
COMPASS_DIA2_Y,1.121
COMPASS_DIA2_Z,0.800
COMPASS_MOT_X,3.354
COMPASS_MOT_Y,0.602
COMPASS_MOT_Z,3.764
COMPASS_MOT2_X,1.648
COMPASS_MOT2_Y,1.537
COMPASS_MOT2_Z,-9.904
COMPASS_MOTCT,2
COMPASS_ODI_X,-0.002
COMPASS_ODI_Y,-0.061
COMPASS_ODI_Z,-0.016
COMPASS_ODI2_X,-0.025
COMPASS_ODI2_Y,0.085
COMPASS_ODI2_Z,-0.003
COMPASS_OFS_X,8
COMPASS_OFS_Y,-210
COMPASS_OFS_Z,92
COMPASS_OFS2_X,440
COMPASS_OFS2_Y,-198
COMPASS_OFS2_Z,272
COMPASS_SCALE,1.00
COMPASS_SCALE2,1.00

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