Abstract:
In the military and some civil fields, autonomous undersea vehicles(AUVs) are required to navigate in a concealed state. Therefore, in this study, the strap-down inertial navigation system(SINS) and long baseline(LBL) are integrated into a single system, in which an LBL beacon sends acoustic signals in different time slots according to a fixed order. After receiving the acoustic signals, the AUV calculates the translational position of each virtual beacon through the SINS. During navigation, the navigation error of the SINS can be corrected by the LBL underwater acoustic positioning information, and the corrected SINS position information can provide a more accurate virtual beacon translation for the LBL positioning. In the process of integrated navigation and positioning, multi-point LBL positioning is carried out by fusing node redundant information, which can improve the positioning accuracy; the historical redundant node is used to replace the missing node to ensure a normal measurement update. The integrated navigation system is verified using a MATLAB simulation. The simulation results showed that the AUV integrated navigation system based on SINS and LBL could fully suppress the pure inertial navigation error when the AUV was concealed, improve the navigation positioning accuracy, and save system energy. After using redundant information, the navigation accuracy, reliability, and fault tolerance of the system were further improved