陀螺仪漂移系数的多位置离心机标定方法及误差分析

Calibration Method and Error Analysis for Multi-Positional Method on Centrifuge of Gyroscope’s Drift Coefficients

摘要: 为了准确标定陀螺仪漂移系数，本文在带反转平台的精密离心机上建立坐标系，并在考虑离心机误差源的情况下分析了坐标系间的位置关系。用齐次变换法推导出了陀螺仪各轴上精确的角速度输入并给出了比力输入标称值，再结合陀螺仪静态误差模型推导出含有陀螺仪漂移系数的各次谐波幅值表达式，通过离心机提供两种向心加速度获得陀螺仪各采样时刻的输出，应用谐波分析法可以求得各次谐波幅值大小，从而利用最小二乘估计对各漂移系数进行辨识。试验仿真表明采用带反转平台的离心机对陀螺仪漂移系数标定时可以有效的规避离心机误差，离心机误差只对于DI、DS和DOS的标定有影响，且影响非常大，须在考虑离心机误差的情况下才能够实现精确标定；对于其他系数标定没有影响。实际标定时需要精确测量反转平台回转轴与盘面的垂直度误差，反转平台回转轴倾角回转误差以及反转平台角速率与主轴角速率的大小之差等以满足标定精度要求。

Abstract: In order to calibrate the drift coefficients of gyro precisely, in the paper, the coordinate systems on precision centrifuge with counter-rotating platform were established, and the positional relationships were analyzed in consideration of centrifuge errors. The accurate angular velocity along each axis of gyro was derived by using homogeneous transformation method and the nominal value of input specific force was given, and each harmonic amplitude expression containing drift coefficients of gyro was derived combining the static error model of gyro. The output at each sampling time of gyro was acquired by providing two centripetal accelerations on centrifuge, and each harmonic amplitude’s value was calculated by using harmonic analysis, thus each drift coefficient could be identified by least squire evaluation. The simulation results show that the method using the counter-rotating platform can avoid the centrifuge errors’ influences and the errors mainly impact on the DI, DS and Dos significantly which should be precisely calibrated in consideration of centrifuge errors; and the errors have no impacts on other coefficients. In real calibration, the perpendicularity between rotating axis of counter-rotating platform and the disk surface, the wobbles of rotating axis of counter-rotating platform and the difference between the angular rate of counter-rotating platform and the main axis should be measured precisely in order to meet the requirement.