Application of gravity passive aided strapdown inertial navigation in underwater vehicles

Underwater navigation technology is the guarantee to ensure the underwater vehicles complete all tasks. A gravity passive aided strapdown inertial navigation system is proposed in order to improve the precision of position of autonomous underwater vehicles (AUVs). Improved unscented Kalman filter (IUKF) is applied in the novel integrated system which is based on gravity gradient characteristics. The main characteristics of strapdown inertial navigation system are presented, gravity-aided navigation system are introduced, and IUKF method is applied to the information fusion of integrated navigation system. Simulation experiments were carried out and the results show that the novel integrated navigation system proposed can get better performance of position precision comparing to the traditional Kalman filtering methods. The simulation experiment results suggest that the IUKF method applied in the gravity passive aided navigation system is capable of greatly improving the long-time navigation position, attitude and velocity precision comparing with the traditional information fusion method.