The euler angle performs slowly to convergence when I rotate the device and then put it stay stationary, both yaw、pitch and roll. What's more,The yaw drift is obvious when the device is stationary.

How can I adjust the covariance of magnetic disturbance and linear acceleration ,increase or decrease?

FQWA_9DOF_GBY_KALMAN 1E-4F

FQWD_9DOF_GBY_KALMAN 0.5F

Is magnetic disturbance time constants concerned about the problem?

FCD_9DOF_GBY_KALMAN

Thanks for help!

Jiao,

Which version of the library are you using? The parameter names you provided don't look right.

In Version 5.00, the 9-axis Kalman parameters are:

// gyro sensor noise covariance units deg^2

#define FQVY_9DOF_GBY_KALMAN 1E4F

// gyro offset random walk units (deg/s)^2

#define FQWB_9DOF_GBY_KALMAN 5E-1F

// geomagnetic inclination angle random walk units deg/s

#define FQWDLT_9DOF_GBY_KALMAN 2E1F

// minimum magnetometer and magnetic disturbance

#define FQVBQD_MIN_9DOF_GBY_KALMAN 7E0F

// minimum and maximum gyro offset in deg/s

#define FGYRO_OFFSET_MIN_9DOF_GBY_KALMAN -5.0F

#define FGYRO_OFFSET_MAX_9DOF_GBY_KALMAN 5.0F

Generally, you tighten mag parameters and loosen gyro parameters to put more emphasis on the magnetic samples.

BUT - as I've noted in other posts, I generally do not expect to see a lot of drift on 9-axis. Maybe a few degrees. Are you sure you are not looking at 6-axis results?

Mike