Study On Drift Analysis And Processing Of Fiber Optical Gyroscope In Sins

With full autonomy and uninterrupted advantages, strapdown inertial navigation system is widely used in the area of military and civilian, especially in military area. The accuracy of strapdown inertial navigation system is one of the important indicators of a country's military strength. There are many factors which affect the accuracy of strapdown inertial navigation system, such as the measurement accuracy of inertial sensor (gyroscope and accelerometer), signal processing speed and accuracy ,posture solver algorithms. Therefore, under the same algorithm selection and hardware conditions, it is the measurement accuracy of gyroscope and accelerometer that becomes a very important factor. Drift is an important performance parameter of gyroscope. However, now most method of processing drift is making the model, and then compensating it according to the model, which is difficult to achieve in real-time system.In this thesis, some work on the analysis and processing of the fiber optical gyroscope (FOG)'s drift signal have been done, which is based on the requirement of high-accuracy strapdown inertial navigation system. The following are the main content done in this thesis.â‘ The static test of a FOG is made, and the drift is gotten. Allan variance is studied, and the analysis of drift is made with Allan variance. The different noise coefficients of drift can also be gotten by Allan variance. The various noise sources are be gotten according to the different noise formation mechanism, which can afford a reference value for improve the accuracy of FOG.â‘¡The drift signal of FOG is processed with wavelet transform threshold-value filtering. The selection principle of wavelet function, threshold-value, the action of threshold-value and decomposition level are studied, focus on the wavelet function and the threshold-value. The optimal filtering scheme is gotten through simulation.â‘¢The different noise coefficients of FOG drift before and after different threshold-values filtering are gotten by Allan variance, which quantitatively verify the filtering result. Therefore, it provides a reference value for FOG and other gyroscope's drift signal processing, and enhances their practical engineering ability to work.