基于随机共振的数字闭环光纤陀螺死区现象抑制

Attenuating dead-band nonlinearity in digital closed-loop FOG based on stochastic resonance effect

为抑制数据闭环光纤陀螺中死区现象引致的非线性性,实验研究了随机共振效应对系统信噪比的影响。实验结果表明,以电阻热噪声作为原始噪声源,配合适当的电路设计,可获得带宽可调、零均值、正态分布的随机噪声;在陀螺闭环反馈环节中的A/D转换器前,引入相应随机噪声,利用二值量化系统的非线性性,基于随机共振效应,可以提高系统信噪比,将陀螺的死区阈值从0.37o/h降至0.15o/h。此外,对于给定的陀螺系统,噪声强度、带宽和采样频率的选择不同,抑制死区现象的效果亦不同。进一步的理论分析表明,该方法可以广泛适用于基于数字闭环结构的微弱信号检测系统。

For the sake of attenuating dead-band nonlinearity in digital closed resonant fiber-optic gyroscopes,the influence of stochastic resonance effect on the signal to noise（S/N） of the system is investigated.According to the experiments,the zero-averaged stochastic noise with normal probability distribution function and adaptable bandwidth could be produced,in which the thermal noise from a resistor is operated as initial noise source and processed by a suitable circuit.The S/N might be improved by stochastic resonance effects,therefore,the nonlinearity due to dead-band phenomena could be decreased from 0.37（？）/h to 0.15（？）/h when this noise is introduced into the feedback loop as an inputting signal of the A/D converter.This attenuation is varied with noise intensity,bandwidth and sampling frequency selected for A/D converter.Finally,theoretic analysis shows that this method might be applied in other weak signal detection systems based on stochastic resonance effect.