Copter 4.4.0 "Error Compass Variance" during a big turn in mission, any idea?

ArduCopter Copter 4.4
1

I have met “error compass variance” when flip.

And I have met it again during a big turn, so any idea?

tlog + binlog, here ( flight two times)

Video here

4.4.0 (self build with VTX changes) + H743 Dual BIM270(Matek H743 slim variant board) + BN880

2

You could try running magfit and see if that improves your compass performance.

3

I have used two bin log, but the results seem quite different.

BTW, I don’t have current meter, so use throttle instead COMPASS_MOTCT =1.

New: Vector3(-9.53, 106.60, -157.93) diag: Vector3(1.20, 1.12, 0.80) offdiag: Vector3(0.01, -0.20, 0.00) cmot_mode: 1 cmot: Vector3(10.00, 10.00, -10.00) scale: 0.93
COMPASS_OFS_X -9
COMPASS_OFS_Y 106
COMPASS_OFS_Z -157
COMPASS_DIA_X 1.200
COMPASS_DIA_Y 1.117
COMPASS_DIA_Z 0.800
COMPASS_ODI_X 0.011
COMPASS_ODI_Y -0.200
COMPASS_ODI_Z 0.003
COMPASS_MOT_X 10.000
COMPASS_MOT_Y 10.000
COMPASS_MOT_Z -10.000
COMPASS_SCALE 0.93
COMPASS_MOTCT 1

New: Vector3(-27.90, 125.44, -172.35) diag: Vector3(1.20, 1.14, 0.80) offdiag: Vector3(0.00, -0.20, -0.03) cmot_mode: 1 cmot: Vector3(10.00, 10.00, -10.00) scale: 0.94
COMPASS_OFS_X -27
COMPASS_OFS_Y 125
COMPASS_OFS_Z -172
COMPASS_DIA_X 1.200
COMPASS_DIA_Y 1.143
COMPASS_DIA_Z 0.800
COMPASS_ODI_X 0.001
COMPASS_ODI_Y -0.200
COMPASS_ODI_Z -0.030
COMPASS_MOT_X 10.000
COMPASS_MOT_Y 10.000
COMPASS_MOT_Z -10.000
COMPASS_SCALE 0.94
COMPASS_MOTCT 1

Consulting: Refining Calibration Parameters using a Flight Log — Copter documentation

4

Either do the calculations without CMOT, but the better solution is to get current monitoring.

1 Like
5

It seems no big difference without CMOT.

New: Vector3(-8.47, 108.86, -159.83) diag: Vector3(1.20, 1.12, 0.80) offdiag: Vector3(0.01, -0.20, 0.00) cmot_mode: 0 cmot: Vector3(0.00, 0.00, 0.00) scale: 0.93
COMPASS_OFS_X -8
COMPASS_OFS_Y 108
COMPASS_OFS_Z -159
COMPASS_DIA_X 1.200
COMPASS_DIA_Y 1.118
COMPASS_DIA_Z 0.800
COMPASS_ODI_X 0.012
COMPASS_ODI_Y -0.200
COMPASS_ODI_Z 0.001
COMPASS_MOT_X 0.000
COMPASS_MOT_Y 0.000
COMPASS_MOT_Z 0.000
COMPASS_SCALE 0.93
COMPASS_MOTCT 0

New: Vector3(-26.65, 126.81, -174.28) diag: Vector3(1.20, 1.14, 0.80) offdiag: Vector3(0.00, -0.20, -0.03) cmot_mode: 0 cmot: Vector3(0.00, 0.00, 0.00) scale: 0.94
COMPASS_OFS_X -26
COMPASS_OFS_Y 126
COMPASS_OFS_Z -174
COMPASS_DIA_X 1.200
COMPASS_DIA_Y 1.142
COMPASS_DIA_Z 0.800
COMPASS_ODI_X 0.002
COMPASS_ODI_Y -0.200
COMPASS_ODI_Z -0.030
COMPASS_MOT_X 0.000
COMPASS_MOT_Y 0.000
COMPASS_MOT_Z 0.000
COMPASS_SCALE 0.94
COMPASS_MOTCT 0

It did much improvement when fly mission. But it still get warning when acro flip.