Cooperative Path Planning for Range-Only Localization Using a Single Moving Beacon

Underwater navigation that relies solely on dead reckoning (DR) suffers from unbounded position error growth. A common approach for alleviating the problem is to have the underwater vehicle surface occasionally for a Global Positioning System (GPS) fix, at the risk of jeopardizing the vehicle´s safety and consuming precious mission time. Other alternatives include deploying a long-baseline (LBL) acoustic positioning system in the mission area; this involves substantial deployment effort. The idea of having active mobile beacons as navigational aids has recently gained interest. We explore the use of a single-beacon vehicle for range-only localization to support other autonomous underwater vehicles (AUVs). Specifically, we focus on cooperative path-planning algorithms for the beacon vehicle using dynamic programming and Markov decision process formulations. These formulations take into account and minimize the positioning errors being accumulated by the supported AUV. This approach avoids the use of LBL acoustic positioning systems as well as allows the supported AUV to remain submerged for a longer period of time with small position error. Simulation results and field trials data demonstrate that the beacon vehicle is able to help keep the position error of the supported AUV small via acoustic range measurements.