数字闭环光纤陀螺动态模型研究

Research on Dynamic Model of Digital Closed-Loop Fiber Optic Gyroscope

由于角振动台测试方法的局限性,难以全频带验证数字闭环光纤陀螺动态模型的正确性。针对此问题,提出了基于Faraday效应的动态特性评估测试方法,采用正弦电流激励下的Faraday相位差等效Sagnac相位差,解决了激励信号输出频率有限的问题。由动态模型推导出传递函数,仿真光纤陀螺的频率特性,仿真结果与实验结果相一致。分析了该动态模型各个参数与闭环带宽的关系,结论与实验拟合结果相同。从以上两个方面验证了该数字闭环光纤陀螺动态模型的正确性,为优化动态特性的研究提供了一定的参考。

It is difficult to verify the dynamic model of the digital closed-loop fiber optic gyroscope （FOG） due to the limitation of the turntable＇s output frequency. To solve this problem, a novel evaluation method based on the magneto-optic Faraday effect is developed. The Sagnac phase difference is substituted by the Faraday phase difference induced by alternating current （AC） to eliminate the limitation of stimuli. Based on the dynamic system model of the FOG, the relationship between bandwidth and the parameters is analyzed and the system transfer function is obtained. The frequency response characteristic of the gyro is simulated via the obtained transfer function. Finally, some experiments are conducted to investigate the dynamic performance of the gyro. The experimental data are in agreement with the theoretical findings, which demonstrates the correctness of the dynamic model and provides the groundwork for optimizing dynamic characteristics.