光纤陀螺数字相位斜波频繁复位抑制算法

Frequent reset suppression algorithm of digital phase ramp in fiber optic gyroscope

针对光纤陀螺在小角速度测量时存在数字相位斜波频繁复位的问题,建立了调制增益漂移条件下复位相位误差模型,分析了数字相位斜波频繁复位的机理和产生的条件。证明了数字相位斜波频繁复位是产生死区的因素之一。提出了一种具有类似施密特触发器特性的数字斜波滞回复位算法,通过分离数字相位斜波正负向累加区间,抑制频繁复位及其引起的死区。实验结果表明,在调制增益变小1%时,采用滞回复位算法可将死区范围从测量噪声的3倍减小至1倍左右。

In view of the problem that the digital phase ramp in fiber optic gyroscope resets frequently at the small angular velocity measurement,the reset phase error is modeled under the condition of the gain drift of the modulation chain.Then the mechanism and condition are analyzed for the frequent reset of the digital phase ramp.It is proved that the frequent reset is one of the factors generating the dead band.A hysteresis reset algorithm of the digital ramp is proposed,which has the similar characteristics with the Schmitt trigger.The algorithm suppresses the frequent reset and resulting dead band by means of separating the positive and negative ramp accumulation interval.The experimental results show that the hysteresis reset algorithm can decrease the dead band from three times to one time measurement noise when the modulation gain lessens by 1%.