Research On Pivotal Technique Of The IFOG

Since the birth, the FOG has been put into application in many ways, especially in Strapdown Inertial Navigation System, for its many advantages such as simple structure, stability, quick-reaction, higher reliability, low cost, small volume and low weight. With many noises such as the noise of light-source and system and some inherent noise, the stability of the FOG is not good. In order to improve the stability, the following has been done:After analyzing the physical characteristic of the gyro, and with many experiments, the transfer function of the system is set up. In the following the discrete function is applied to adaptive filtering. With that the random noise is filtered out.The change of the wavelength may lead to the drift of the non-exchange phase drift, so influence the stability of the scale factor, also it is known the temperature is the key factor that affect the wavelength of the light-source. In order to eliminate the noise of the source and boost the stability, the temperature control circuit and the power control circuit are designed.The fiber ring is one of the important part of the FOG, and it has great effect on the stability of the FOG. Owing to the exist of the temperature grads and stress grads, the noise in the light circuit is increased and so the wave phase of the fiber ring is affected, and this reduce the stability. After analysis the QAD method is used, and the method proved to be effective after many tests. With that the non-exchange noise is filtered out.