一种光纤IMU的双轴非定向标定方法

Calibration method for FOG IMU without orientation based on two-axis indexing

针对光纤惯性组件确定性误差的特性,建立了标定的数学模型。由于光纤组件标度因数的非线性,使用多项式误差模型替代了经典的常数误差模型。基于建立的模型提出了一种双轴转位机构动静态混合标定方案,使用八位置静态标定方法标定陀螺零偏,采用三轴12个速率的旋转标定方法标定陀螺标度因数误差和非正交耦合误差。针对加速度计采用二十四位置的重力场静态翻滚标定方案,最后使用多项式拟合的数据处理方法计算和补偿光纤惯性组件的标度因数误差。通过实验和补偿结果表明,此方案有效标定了光纤惯性组件的各项确定性误差。

Based on the characteristics of fiber optic gyroscope （FOG） inertial measurement unit （IMU） deterministic error,a calibration model is established. Considering the nonlinear scale factor of FOG IMU, polynomial error model is used instead of the classical constant error model. According to the calibration model,a calibration method using two- axis indexing is presented, combining position and rotation. An eight-position experiment method is presented to calibrate the gyro bias; a twelve-rate rotation around three-axis experiment method is presented to calibrate the gyro scale factor and installation error; a twenty-four-position in gravitational fiel.d experiment method is presented to calibrate the accelerometer. Besides, the error correction algorithm is proposed based on the least-square polynomial fitting method. The experiment and compensation results prove that the calibration method can accurately determine the definite error coefficients of FOG IMU.