惯组中光纤陀螺温度漂移的二维插值建模研究

Research on Two-dimensional Interpolation Modeling of Temperature Drift of Fiber Optic Gyro in IMU

光纤陀螺对温度较为敏感,输出受温度及温度变化率影响严重,在实际工作中需要对温度漂移误差进行建模补偿。传统多项式拟合方法如最小二乘法,无法很好地满足精度要求。因此,首先对光纤陀螺工作原理与温度漂移误差产生原理进行分析,得出光纤陀螺温度漂移误差特性。利用传统多项式模型对不同温度下启动的光纤陀螺进行建模补偿,得到补偿后的精度并不理想。利用新的二维插值模型对上述试验重新进行建模补偿,结果表明二维插值模型明显优于多项式模型,光纤陀螺的零偏稳定性由补偿前的0.0153(°)/h提高到0.0051(°)/h,有利于工程上应用。

Fiber optic gyroscope(FOG)is sensitive to temperature,and the output can be easily affected by temperature and temperature change rate.In actual work,it is necessary to use a modeling method to compensate for the temperature drift error.Traditional polynomial fitting methods,such as the least square method,cannot meet the accuracy requirements.In order to solve this problem,the operation principle of the FOG and the generating mechanism of temperature drift error are analyzed.Then the temperature drift error characteristic of FOG is calculated.And the polynomial model is used to model and compensate for FOGs at different temperatures.The accuracy after FOG compensation is not ideal.The two-dimensional interpolation model is used to model and compensate for the previous experiment.The results show that the two-dimensional interpolation model is significantly better than the polynomial model.The bias stability of the fiber optic gyro is improved from 0.0153(°)/h(before compensation)to 0.0051(°)/h,which is beneficial to engineering applications.