提高光纤陀螺开机零偏稳定性的调制方法

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.

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

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.