基于锯齿波偏频的谐振式光纤陀螺标度因数测试

Scale Factor Test of Resonance Fiber Optic Gyroscope Based on Biased Sawtooth Wave

针对转台测试谐振式光纤陀螺标度因数时存在的测试精度受限于转台性能影响的问题,提出一种基于锯齿波等效输入的陀螺标度因数测试方法.通过在相位调制器上叠加锯齿波偏频信号用于模拟角速度输入,分析了实际转台输入和模拟角速度输入下谐振式光纤陀螺闭环传递函数,推导了偏频锯齿波信号参数与实际输入角速度的对应关系,理论证明了其技术可行性.搭建了基于锯齿波偏频的陀螺标度因数测试系统,对研制的陀螺样机进行了标度因数及非线性度测试,基于锯齿波偏频方法测得的陀螺标度因数与实际转台测试结果基本一致,且标度因数非线性度从0.42%优化到0.26%.研究表明基于锯齿波偏频的谐振式光纤陀螺标度因数快速标定测试方法不仅可以精确测得标度因数,还可有效抑制转台振动等环境干扰引入的测量误差.

In order to solve the problem that the accuracy of scale factor measurement of Resonance Fiber Optic Gyroscope(RFOG)is limited by the performance of turntable,a new method based on sawtooth equivalent input was proposed.By adding sawtooth wave to the RFOG′s phase modulator,which works as equivalent input angular velocity,the RFOG closed-loop transfer functions under turntable input and equivalent input were analyzed,relationship between the parameter of sawtooth and equivalent input angular velocity was given,the scale factor and non-linearity were obtained by the scale factor test system.The scale factor is basically identical to the test result on the turntable,and the non-linearity is also improved from 0.42%to 0.26%.The test results demostrate that the scale factor test system based on sawtooth equivalent input can accurately measure the scale factor of RFOG,and effectively eliminate the measurement errors due to the vibration and imperfect precision of the turntable.