Acoustic-based techniques for autonomous underwater vehicle localization

This paper presents two acoustic-based techniques to solve the localization problem for an autonomous underwater vehicle (AUV). After a brief description of the Bayesian filtering framework, the paper analyses two of the most common underwater scenarios. Each scenario corresponds to one of the two localization techniques. The scenarios are as follows: map-based localization, when the environment is sufficiently distinctive; transponder-based localization for navigation in large and not distinctive environments. An environment is said to be distinctive when there are possible reference points. For example, a completely flat featureless sea floor is not considered as distinctive. The proposed techniques were validated in simulation. The mapbased localization technique was also validated in trials with the autonomous underwater vehicles Ictineu and Nessie IV. The trials with Ictineu took place in an abandoned marina with Ictineu travelling along a trajectory that was more than 600 m long. The trials with Nessie IV took place in a rectangular pool and during an AUV competition.