A Robust Seabed Terrain Contour Aid Navigation Method Facing the Smooth Terrain

The underwater terrain-aid navigation (TAN) method using a single-beam sonar has demonstrated its potential for autonomous underwater vehicles (AUVs) long-range accurate navigation without the aid of acoustics arrays and satellites. This paper proposed a robust terrain contour aid navigation(TCAN) method using a single-beam sonar in the smooth terrain areas, which considered the error characteristics of an inertial navigation system(INS), can realize long-range underwater navigation. As for the measurement error of a single-beam sonar and the influence of the smooth terrain areas, this paper proposed a measurement confidence interval calculation method, which can reduce the influence of the measurement error on the navigational result, improving the accuracy and robustness of the TCAN method. The influence of algorithm parameters on the result of the navigation method are researched by simulation experiments. The results show that the navigation method can realize long-range underwater navigation in the smooth terrain areas on making full use of an INS error characteristics, and has a good application prospect.