An improved cooperative localization method for multiple autonomous underwater vehicles based on acoustic round-trip ranging

Cooperative localization (CL) plays an important role in the application of multiple autonomous underwater vehicles (AUVs) simultaneously, by communicating with each other through acoustic modems on-board, which can not only increase the navigation performance but also reduce the navigation cost. Compared to one-way-ranging (OWR) based on precise time synchronized, the round-trip ranging (RTR) is simple and widely used for AUVs CL. However, it is challenging for existing scheme that the low update rate for each AUV restricts the number of AUVs cooperated seriously. To improve the performance of multiple AUVs CL based on RTR, we propose a new message exchange mechanism that reduce message exchange times and then the overall update rate is increased for each AUV. Simulation and lake-water field trial results confirm the advantage of the proposed CL scheme for multiple AUVs based on acoustic RTR.