光纤陀螺IMU的六位置旋转现场标定新方法

Novel Field Calibration Through Rotation in Six-position for FOG-IMU

针对光纤陀螺惯性测量单元(Inertial Measurement Unit,IMU)的误差系数随时间推移而变化的问题,本文提出一种光纤陀螺IMU的六位置旋转现场高精度标定新方法,该方法在使用现场将光纤陀螺IMU在六个位置上进行十二次旋转,然后根据光纤陀螺IMU的误差模型建立42个非线性输入输出方程,通过旋转积分和对称位置误差相消,消除方程中的非线性项,最终求解出陀螺标度因数、陀螺常值漂移、陀螺安装误差和加速度计常值偏置等15个误差系数。实验结果表明,该方法可在没有精密转台的现场实现光纤陀螺IMU的精确标定,其标定精度与基于精密转台的标定精度相当。

To improve the accuracy of Strapdown Inertial Navigation System （SINS） based on fiber optic gyro （FOG）, the errors of Inertial Measurement Unit （IMU） must be calibrated in laboratory through precise turntable and compensated in SINS. However, the error coefficients of IMU are not stable and vary with time slowly, which degrades the SINS severely in application. To solve the problem, a novel field calibration method is proposed in this paper. The FOG-IMU was rotated 12 times in six-position, and 48 non-linear equations were established according to the error model of FOG-IMU. The non-linear components in these equations were eliminated through the FOG-IMU rotation and the symmetrical position. Therefore, these non-linear equations were transferred to linear equations. Then the error coefficients were calculated by solving these linear equations. Finally, the experiment was carried out, and the experiment results indicate that the novel calibration method can accurately determine 15 error coefficients of FOG-IMU, and the accuracy of this method is equivalent to the classical calibration with the precise turntable.