Error Analysis And Compensation Techniques Of RLG Ins Under Vibration Environment

Modern warfare proposes higher requirements to strike accuracy and maneuverability of weapon systems like guided missiles, so improving the navigation system performances of the missiles is very urgent. At present, the ring laser gyro strapdown inertial navigation systems have already been used in many weapon systems, while its navigation precision will dramatically degrade in medium-range or long-range missile system because of the dynamic error sources like vibration. In this paper, the error mechanism and compensation techniques of ring laser gyro strapdown inertial navigation systems was studied under vibration environment, aiming at improving the precision of ring laser gyro strapdown inertial navigation systems and making them suitable for use in medium-range or long-range missiles.First of all, based on the navigation basic equations and the inertial sensors’ error model, the navigation error characteristics under the line vibration and angular vibration environments was studied through simulation respectively. The navigation error introduced by the cross-coupling error under the line vibration environment was selectively analyzed, and the navigation error introduced by the angular vibration was also analyzed.Secondly, the frequency-domain characteristics of ring laser gyro strapdown inertial navigation systems on static base and under line vibration environment were studied respectively. Considering the special requirements of specific weapon systems, such as the guided missile, to time delay, a filtering scheme of low order FIR filter plus adaptive IIR trap filter for data preprocessing was designed. The filtering effect was basically guaranteed, and the time delay of the system was reduced at the same time.Thirdly, the size effect error of the accelerometers in ring laser gyro inertial navigation system was studied, and an approach for size effect error identification was developed, which could be easily implemented in engineering applications. Experiments showed that the size effect error of the system under vibration environment had been compensated perfectly.Finally, the drifts of inertial sensors in ring laser gyro inertial navigation system under vibration environment were discussed. To estimate the drifts of the inertial sensors under vibration environment, a two position Kalman filter method for initial alignment drift estimation was designed. A series of error compensation experiments showed that the precision of the navigation system was improved by more than 35%...