Path planning for cooperative underwater range-only navigation using a single beacon

Autonomous underwater vehicles (AUVs) that rely on dead reckoning suffer from unbounded localization error growth at a rate dependent on the quality (and cost) of the navigational sensors. Many AUVs surface occasionally to get a GPS position update. Alternatively underwater acoustic beacons such as long baseline (LBL) arrays are used for localization, at the cost of substantial deployment effort. The idea of cooperative localization with a few vehicles with high navigation accuracy (beacon vehicles) among a team of AUVs with poor navigational sensors has recently gained interest. Autonomous surface crafts (ASCs) with GPS, or sophisticated AUVs with expensive navigational sensors may play the role of beacon vehicles. Other AUVs are able to measure their range to these acoustically, and use the resulting information for self-localization. Since a single range measurement is insufficient for unambiguous localization, multiple beacon vehicles are usually required. In this paper, we explore the use of a single beacon vehicle to support multiple AUVs. We develop path planning algorithms for the beacon vehicle that take into account and minimize the errors being accumulated by other AUVs. We show that the generated beacon vehicle path enables the other AUVs to get sufficient information to keep their localization errors bounded over time.