Practical Velocity-Updating Algorithm of Strapdown Inertial Navigation System with Ring Laser Gyro

Strapdown inertial navigation system (SINS) with ring laser gyro (RLG) has been used extensively in the autonomous underwater vehicle (AUV) for the apparent advantages of having wide dynamic range, digital output and high accuracy. Because of the dithering motion of RLG to overcome the lock-in threshold and the vibration of AUV, there is sculling error in velocity-updating process of SINS. This paper firstly proposes a conventional sculling model based on optimum compensation algorithm. Recurrent compensation algorithm, which is called practical velocity-updating algorithm, is developed and emphasized briefly. In order to validate the performance of the proposed algorithms, simulation under classical sculling motion and RLG dithering are carried on. Simulation results show that recurrent compensation algorithm is more practical in AUV with RLG dithering condition.