正弦波调制的光纤环本征频率测量方法

为了弥补传统光纤环本征频率测量方法中方波调制存在死区的缺陷,提出正弦波调制的本征频率测量方法。对正弦波调制下的光纤陀螺输出信号进行分析,得到二次谐波幅度与调制频率间的二次函数关系,通过计算抛物线顶点即可求得本征频率。依据该原理对已有的光纤陀螺进行升级改造,研制了一套本征频率测量系统。试验结果表明:该方法可达到1×10-5的测量精度,是一种成本低、精度高的光纤环本征频率测量方法。

Method for fiber ring eigenfrequency by sine wave modulation

A new measuring method for fiber ring eignfrequency was presented. Being different from common square wave modulating, the new method is based on sine wave modulation, so the problem of dead zone is solved. Output signal of fiber optic gyroscope was analyzed when using sine wave modulation, quadratic relationship was got between second harmonic and modulation frequency, eignfrequency can be got by calculating the parabolic vertex. On the basis of the new method, a test system was developed by updating fiber optic gyroscope system. Test result shows that the measuring precision of 10 ppm can be achieved, which is a low cost and high precision method for fiber ring eignfrequency.