Cooperative single-beacon multiple AUV navigation under stringent communication bandwidth constraints

In this paper we propose a method of cooperative navigation of a fleet of AUVs moving in formation with stringent limitations on the bandwidth of the underlying acoustic communications network. In the methodology proposed, one vehicle is equipped with a DVL and the others are equipped with acoustic modems and range-measuring devices that can only measure ranges to the remaining vehicles in the formation and to an underwater beacon or transponder located at a known position. Based on DVL and range measurements, and through the exchange of information among the vehicles, each vehicle must estimate its own position and the positions of the other vehicles in the fleet. The estimates obtained are then used for geo-referencing purposes as well as formation control. We use methods of distributed and quantised state estimation to solve this problem. We investigate through numerical simulations what type of information should be shared among the vehicles (range measurements or position estimates) for an efficient tradeoff between bandwidth and state estimation performance, which may lead to a better scalability of the formation.