Fiber Optic Gyroscope Signal Wavelet Filtering Technique

In the shipborne Electro-optical tracking system,to ensure the tracking accuracy of the moving target,we must first ensure the stability accuracy of the LOS stabilization subsystem.The system usually uses the inertial stabilization platform to isolate the interference of the carrier to the tracking system and realize the stability of the LOS stabilization subsystem.The fiber optic gyroscope in the inertial stabilization platform measures and outputs the real-time disturbance(angle,angular velocity,etc.)of moving targets and perturbations relative to the inertial space.In the shipborne LOS stabilization subsystem,we usually use the composite control of feedforward and feedback,the output signal of the fiber optic gyro is transmitted as a feedback control signal to the system,and the extracted disturbance information is transmitted as feedforward control signal to the system.Because the low frequency band of the disturbance signal coincides with the moving target signal,it is difficult to separate,and the stable platform has good suppression of low frequency disturbance,so the fiber optic gyro output signal filtering process,get the high-frequency signal as a feedforward control signal.In this context,filter the fiber optic gyro output signal,so extract the middle and high frequency signals as the feedforward control signals of the stable platform in the case of small amplitude and phase distortion,which is of great significance to further improve the accuracy of the visual axis stability.First of all,this paper spectrum analyzes the output signal of fiber optic gyroscope,and provides the basis for the follow-up study.Focusing on several commonly used fiber optic gyro signal processing methods,and IIR filtering,lifting wavelet filtering and harmonic wavelet filtering are selected to filter the output signal of the fiber gyroscope and compare the filtering effect.When the signal is filtered based on the lifting wavelet threshold filtering method,the middle and high frequency signals are obtained by filtering the output signal of the fiber gyroscope by selecting the appropriate wavelet base,decomposition scale and threshold value.When the fiber optic gyro output signal is filtered based on the harmonic wavelet filtering method,the target signal is extracted by setting the appropriate harmonic wavelet upper and lower frequency values.The experimental results show that the effect of harmonic wavelet filtering is better than that of lifting wavelet filtering and IIR filtering,and the effect of wavelet filtering is better than that of IIR filter.In this paper,the harmonic filtering scheme is selected to filter the output signal of fiber optic gyroscope.Finally,this paper presents an algorithm for real-time filtering of the output signal of fiber optic gyroscope and extracting the middle and high frequency signals.Firstly,the signal is intercepted and symmetrically extended,and then the middle and high frequency signals are obtained by harmonic wavelet filtering,and the experimental results are given.The signal processing method proposed in this paper is experimentally verified on the experimental platform.The results show that this method can effectively separate the middle and high frequency signals of the fiber optic gyroscope,and the separation rate is high,the amplitude and phase distortion are small,and the stability accuracy of the LOS stabilization subsystem.