Problems with horizon without GPS

Hellow, I have two identical copters with an F405 FC, one I used to fly on Betaflight, the other I built for use with Arducopter. And I noticed a problem that Arducopter has a problem with flying without a GPS module.
In ACRO or in Stab, after high-speed maneuvers, the horizon (on OSD and in logs) becomes different from the real one on ±15-30 degrees. When the GPS was turned on, I observed this phenomenon only once.
At the same time, I have never seen such problem in Betaflight, no matter what maneuvers I make.

What is the problem? And how should it be solved?

I’m currently trying to understand how the EKF3 works, and how to tuning it to solve this problem.

I would be grateful for your help.

My params of ahrs, ek3:

EKF3:

EK3_ABIAS_P_NSE,0.02
EK3_ACC_BIAS_LIM,1
EK3_ACC_P_NSE,0.35
EK3_AFFINITY,0
EK3_ALT_M_NSE,2
EK3_BCN_DELAY,50
EK3_BCN_I_GTE,500
EK3_BCN_M_NSE,1
EK3_BETA_MASK,0
EK3_CHECK_SCALE,100
EK3_DRAG_BCOEF_X,0
EK3_DRAG_BCOEF_Y,0
EK3_DRAG_M_NSE,0.5
EK3_DRAG_MCOEF,0
EK3_EAS_I_GATE,400
EK3_EAS_M_NSE,1.4
EK3_ENABLE,1
EK3_ERR_THRESH,0.2
EK3_FLOW_DELAY,10
EK3_FLOW_I_GATE,300
EK3_FLOW_M_NSE,0.25
EK3_FLOW_USE,1
EK3_GBIAS_P_NSE,0.001
EK3_GLITCH_RAD,25
EK3_GND_EFF_DZ,4
EK3_GPS_CHECK,31
EK3_GPS_VACC_MAX,0
EK3_GSF_RST_MAX,2
EK3_GSF_RUN_MASK,3
EK3_GSF_USE_MASK,3
EK3_GYRO_P_NSE,0.015
EK3_HGT_DELAY,60
EK3_HGT_I_GATE,500
EK3_HRT_FILT,2
EK3_IMU_MASK,1
EK3_LOG_LEVEL,0
EK3_MAG_CAL,3
EK3_MAG_EF_LIM,50
EK3_MAG_I_GATE,300
EK3_MAG_M_NSE,0.05
EK3_MAG_MASK,0
EK3_MAGB_P_NSE,0.0001
EK3_MAGE_P_NSE,0.001
EK3_MAX_FLOW,2.5
EK3_NOAID_M_NSE,10
EK3_OGN_HGT_MASK,0
EK3_OGNM_TEST_SF,2
EK3_POS_I_GATE,500
EK3_POSNE_M_NSE,0.5
EK3_PRIMARY,0
EK3_RNG_I_GATE,500
EK3_RNG_M_NSE,0.5
EK3_RNG_USE_HGT,-1
EK3_RNG_USE_SPD,2
EK3_SRC_OPTIONS,1
EK3_SRC1_POSXY,3
EK3_SRC1_POSZ,1
EK3_SRC1_VELXY,3
EK3_SRC1_VELZ,3
EK3_SRC1_YAW,1
EK3_SRC2_POSXY,0
EK3_SRC2_POSZ,1
EK3_SRC2_VELXY,0
EK3_SRC2_VELZ,0
EK3_SRC2_YAW,0
EK3_SRC3_POSXY,0
EK3_SRC3_POSZ,1
EK3_SRC3_VELXY,0
EK3_SRC3_VELZ,0
EK3_SRC3_YAW,0
EK3_TAU_OUTPUT,25
EK3_TERR_GRAD,0.1
EK3_VEL_I_GATE,500
EK3_VELD_M_NSE,0.5
EK3_VELNE_M_NSE,0.3
EK3_VIS_VERR_MAX,0.9
EK3_VIS_VERR_MIN,0.1
EK3_WENC_VERR,0.1
EK3_WIND_P_NSE,0.2
EK3_WIND_PSCALE,1
EK3_YAW_I_GATE,300
EK3_YAW_M_NSE,0.5

AHRS:

AHRS_COMP_BETA,0.1
AHRS_EKF_TYPE,3
AHRS_GPS_GAIN,1
AHRS_GPS_MINSATS,6
AHRS_GPS_USE,1
AHRS_OPTIONS,0
AHRS_ORIENTATION,0
AHRS_RP_P,0.2
AHRS_TRIM_X,0.01765343
AHRS_TRIM_Y,0.03191613
AHRS_TRIM_Z,0
AHRS_WIND_MAX,0
AHRS_YAW_P,0.2
1 Like

Hi, I have the same problem. Did you find solution?

Hi!
Not yet.

But I think, that I should test this list of params:

AHRS_EKF_TYPE,3
AHRS_GPS_USE,0
COMPASS_ENABLE,0
COMPASS_USE,0
COMPASS_USE2,0
COMPASS_USE3,0
EK3_ENABLE,1
EK3_IMU_MASK,1
EK3_FLOW_USE,0
EK3_RNG_USE_HGT,-1
EK3_SRC_OPTIONS,0
EK3_SRC1_POSXY,0
EK3_SRC1_POSZ,1
EK3_SRC1_VELXY,0
EK3_SRC1_VELZ,0
EK3_SRC1_YAW,0
EK3_SRC2_POSXY,0
EK3_SRC2_POSZ,1
EK3_SRC2_VELXY,0
EK3_SRC2_VELZ,0
EK3_SRC2_YAW,0
EK3_SRC3_POSXY,0
EK3_SRC3_POSZ,1
EK3_SRC3_VELXY,0
EK3_SRC3_VELZ,0
EK3_SRC3_YAW,0
GPS_TYPE,0
GPS_TYPE2,0
INS_ACC_BODYFIX,2
INS_ENABLE_MASK,127
INS_FAST_SAMPLE,3

@t4b4k , I tested these parameters, I can’t say that it has become better. Still after fast maneuvers in acro and after switching to stab or althold the horizon doesn’t correspond to the real one. At the same time after some time it becomes normal again and then again begins to differ. It`s very strange thing. I don’t know how make it better.