Error analysis for SINS with different IMU rotation scheme

Influence on Strapdown Inertial Navigation System (SINS) error characteristics for different IMU (inertial measurement unit) rotation schemes was analyzed theoretically.It's indicated that, in single-axial and single-directed rotation scheme the gyro's bias on rotational axis was not modulated, but a equivalent bias calculate by scale-factor error multiplying rotating velocity was introduced in rotational axis,which limit the position precision of the SINS. But in dual-axial and single-directed rotation scheme, both gyro's bias and aforementioned equivalent bias were modulated, whenas another equivalent bias caused by coupling of the scale-factor error and the movement of vehicle were introduced and this bias also limited the position precision. The analysis in theory was proved by simulation.