谐振式微光学陀螺频率跟踪与锁定技术研究

Frequency Tracking and Locking Methods in Resonator Micro-Optic Gyro

谐振式微光学陀螺(RMOG)是利用光学Sagnac效应和微电子机械系统(MEMS)加工工艺实现的一种新型角速度惯性传感器。为了减小光学器件受温度、应力等外界环境变化的影响,提高陀螺性能,快速精确的频率跟踪与锁定技术是非常必要的。提出了两种应用于RMOG的频率跟踪与锁定方法:单路光路(单路模式)和两相向传输光路(双路共模模式);分析比较了两种方案应用于RMOG中所得到的陀螺性能。单路模式由于受光路非互易性噪声的影响较小,锁频精度高;双路共模模式频率跟踪速度快,动态响应性能好。对RMOG的测试表明,对应于单路模式和双路共模模式,分别可以得到0.07°/s的频率锁定精度和0.09 ms.[(°)/s]-1的频率跟踪速度。

As one of the new rotation rate sensing devices, resonator micro-optic gyro （RMOG）, incorporating optical Sagnac effect and micro-electromechanical systems （MEMS） fabrication technique, makes essential sense in promoting miniaturized and sensitive gyros. Fast and accurate frequency tracking and locking technique is quite important to suppress the drift induced by environmental temperature and mechanical variations. Two frequency tracking and locking methods, based on single light path （single mode） and common part of both counter-propagating light paths （common mode）, are presented and applied on established RMOG system. For the single mode method, signal from single light path is detected to feedback and control the light frequency, where the influence of nonreciprocal optical noise is neglectable. However, in the latter case, the common mode of the two counterpropagating lights is used, which is a constant during the rotating state variation, representing fast frequency tracking speed. Testing results show that the frequency tracking time of 0.09 ms , [（°）/s]^-1 under rotation rate variation and frequency locking precision of 0.07 °/s for over lh by single mode and common mode frequency tracking and locking methods for the RMOG system, respectively.