提高光纤陀螺开机零偏稳定性的调制方法

Modulation method for stabilizing zero-bias of FOG during warm-up

针对光纤陀螺在开机启动时零偏不稳定的问题,从机理上分析了2π电压初始对准及前向增益变化对零偏的影响.提出了一种新的组合调制方法,通过4种状态的调制、解调,实现了对Y波导2π电压的快速调整,有效缩短2π电压在陀螺开机时的初始对准时间,由5min缩短至1 s,克服了目前方波调制的缺陷.经频域分析和实验验证,该组合调制方法还可以抑制由调制引起的交叉干扰,能够有效抑制前向增益变化对陀螺零偏的影响,从而使前向增益变化导致的陀螺开机零偏变化由0.03(°)/h减小至0.01(°)/h.

To solve the zero-bias fluctuation problem of fiber-optic gyroscope（FOG） during its warm-up,the influences of initial alignment of 2π voltage and anterior gain fluctuation on the zero-bias of FOG were analyzed,respectively.A novel hybrid modulation method,namely four-state modulation method was proposed,by which the drawback of conventional square wave modulation method can be overcome.Due to this proposed four-state modulation and demodulation method,the rapid adjustment of Y waveguide 2π voltage was realized,which reduces the adjusting time of the warm-up from 5 minutes to 1 second.Owing to the analysis in the frequency domain,it was presented that the proposed four-state modulation and demodulation method can also suppress the crosstalk induced by modulation and suppress the influence of the anterior gain on the zero-bias fluctuation.As a result,the change of the anterior gain fluctuation induced zero-bias of FOG during warm-up is improved from 0.03（°）/h to 0.01（°）/h.