New methods to improve the performance of open and closed loop fiber-optic gyros

The paper describes the concept of an open loop fiber-optic gyro (FOG) with digital output and improved scale factor stability. This stability is reached by stabilizing the amplitude of rotation signal and biasing modulation depth. FOGs with closed first and second feedback loops are described, and method of dead zone elimination are outlined. A method of reducing the setup time for gyros with open first feedback loop and with two closed feedback loops by correcting their output is presented. Compensation of parasitic effects in phase modulators of integrated optic chip is proposed as a further perspective of improving FOG accuracy. © 2015, Pleiades Publishing, Ltd.