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

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%.