Method of suppression of impulse interferences in digital closed loop fiber optic gyro detected signal

Periodic impulse interferences in the detected signal of digital closed loop fiber optic gyro lead to a bias error. In this paper, three kinds of interference sources, D/A converter and phase modulator, light source, and system power supply, are discussed and verified by an open-loop testing approach. A method with an integration of a digital average algorithm and a soft-switching median filter is proposed to suppress the periodic impulse interferences in detected signal. Selection criterions of the parameters used in the method are discussed and verified through simulation. Some considerations for the practical realization of the method within FPGA are given. An experimental verification of the method is presented by applying it to three gyros corrupted by periodic impulse interferences. The results demonstrated that the bias error could be decreased by about 85% with the method proposed.