Using matrix optics and optical propagation theory, a model for bias errors of an optical fiber gyroscope (FOG) caused by the spherical nonuniform distribute magnetic field has been deduced. Based on the above model, the effect on the FOG caused by the nonuniform distribute magnetic field and common circuit board is also analyzed. Results indicate that, i) the nearer of distance between the center of magnetic field and the fiber loop, the bigger of the bias errors of FOG will be; ii) relationship between bias and magnetic field direction is a inclined sine; iii) outside of the loop, the bigger of the height H0, the smaller of the bias error will be; iv) inside of the loop, the bias error is independent on the height H0; v) the common circuit board which radiate intensity is very weak can also cause unstable and direction related of the FOG’s output. Abolve conclusions may be useful for understanding the effect of actual magnetic field.
|