The Research Of Terrain-aided Underwater Navigation

As the cumulate error, inertial navigation system can't provide perfect position and navigation for the Autonomous Underwater Vehicles (AUV) in unstructured, complex and instable ocean in a long time. The application of terrain-aided navigation techniques to the updating of an inertia navigation system has been investigated. In this paper, the main research works are as follows:1) Survey and analysis previous work in AUV navigation and summarize: As the cumulate error, the dead-reckoning and inertial navigation systems can't be used without other modified system; the acoustic navigation system is used only in small range, and is very expensive.2) Two important approaches in geophysical navigation techniques are summarized, one is terrain contour based navigation, this approach is investigated keystone today; the other is image based navigation, due to no perfect image sensors and image seabed map, this approach has seldom been practised.3) Two important terrain contour based navigation algorithms has been applied to AUV, one is match algorithm-based Terrain Contour Match (TERCOM); the other is Kalman filter-based Sandia Inertia Terrain-aided Navigation (SITAN). The first algorithm is low precise but simple and credible, the second is high precise but complex and incredible.4) Developed four kinds of methods aimed to improve precision and credibility of navigation system. The first is Parallel Sandia Inertia Terrain-aided Navigation (PSITAN); The second is TERCOM+SITAN, it can restrain two important disadvantages of SITAN; The third is Particle filter-based Terrain-aided Navigation (PFTAN), the particle filter can reduce the error of navigation; The last is TERCOM+PFTAN, where TERCOM is looked as monitor to ensure the credibility of navigation system.