@article {2848, title = {Cooperative navigation of AUVs via acoustic communication networking: field experience with the Typhoon vehicles}, journal = {AUTONOMOUS ROBOTS}, volume = {40}, year = {2016}, month = {10/2016}, pages = {1229{\textendash}1244}, abstract = {

A cooperative navigation procedure for a team of autonomous underwater vehicles (AUVs) is described and validated on experimental data. The procedure relies on acoustic communication networking among the AUVs and/or fixed acoustic nodes, and it is suitable as a low-cost solution for team navigation. Embedding the acoustic localization measurements in the communication scheme causes delays and sometimes loss of acoustic data, depending on acoustic propagation conditions. Despite this drawback, the results obtained show that on-board localization estimates have an error of the order of few meters, improving the overall navigation performance and leading the system towards long-term autonomy in terms of operating mission time, without the need of periodic resurfacings dedicated to reset the estimation error. The data were collected during the CommsNet\ {\textquoteright}13 experiment, led by the NATO Science and Technology Organization Center for Maritime Research and Experimentation (CMRE), and the Breaking The Surface\ {\textquoteright}14 workshop, organized by the University of Zagreb.

}, keywords = {Robotics}, issn = {0929-5593}, doi = {10.1007/s10514-016-9594-9}, url = {http://link.springer.com/journal/volumesAndIssues/10514}, author = {B. Allotta and A. Caiti and R. Costanzi and F. Di Corato and D. Fenucci and N. Monni and L. Pugi and A. Ridolfi} } @article {2846, title = {An unscented Kalman filter based navigation algorithm for autonomous underwater vehicles}, journal = {Mechatronics}, volume = {39}, year = {2016}, month = {11/2016}, pages = {185-195}, abstract = {

Robust and performing navigation systems for Autonomous Underwater Vehicles (AUVs) play a discriminant role towards the success of complex underwater missions involving one or more AUVs. The quality of the filtering algorithm for the estimation of the AUV navigation state strongly affects the performance of the overall system. In this paper, the authors present a comparison between the Extended Kalman Filter (EKF) approach, classically used in the field of underwater robotics and an Unscented Kalman Filter (UKF). The comparison results to be significant as the two strategies of filtering are based on the same process and sensors models. The UKF-based approach, here adapted to the AUV case, demonstrates to be a good trade-off between estimation accuracy and computational load. UKF has not yet been extensively used in practical underwater applications, even if it turns out to be quite promising. The proposed results rely on the data acquired during a sea mission performed by one of the two Typhoon class vehicles involved in the NATO CommsNet13 experiment (held in September 2013). As ground truth for performance evaluation and comparison, performed offline, position measurements obtained through Ultra-Short BaseLine (USBL) fixes are used. The result analysis leads to identify both the strategies as effective for the purpose of being included in the control loop of an AUV. The UKF approach demonstrates higher performance encouraging its implementation as a more suitable navigation algorithm even if, up to now, it is still not used much in this field.

}, keywords = {Robotics}, doi = {http://dx.doi.org/10.1016/j.mechatronics.2016.05.007}, url = {http://www.sciencedirect.com/science/article/pii/S095741581630037X}, author = {B. Allotta and A. Caiti and L. Chisci and R. Costanzi and F. Di Corato and D. Fantacci and D. Fenucci and E. Meli and A. Ridolfi} }