@article {2847, title = {An Attitude Estimation Algorithm for Mobile Robots under Unknown Magnetic Disturbances}, journal = {IEEE/ASME TRANSACTIONS ON MECHATRONICS}, volume = {21}, year = {2016}, pages = {1900-1911}, chapter = {1900}, abstract = {
Attitude estimation is a crucial aspect for navigation and motion control of autonomous vehicles. This concept is particularly true in the case of unavailability of localization sensors when navigation and control rely on dead reckoning strategies; in this case, indeed, the orientation estimate is also used along with speed measurements to update the position estimate. Among the different approaches proposed in the literature, the de facto state of the art in this field is represented by nonlinear complementary filters: they fuse the measurements of angular rate obtained through gyroscopes, and a measurement of gravity and Earth{\textquoteright}s magnetic field vectors respectively obtained through accelerometers and magnetometers. This paper is focused on an attitude estimation strategy for autonomous underwater vehicles (AUV). The proposed novelty includes the identification of some critical issues that arise when AUV attitude estimation algorithms are applied in practice.
They are mainly due to the use of low-accuracy low-cost microelectromechanical systems (MEMS) sensors and on different sources of magnetic disturbances. Some strategies to overcome the identified issues are proposed, including the integration of a single-axis fiber optic gyroscope (FOG) that ensures a considerable performance improvement with a moderate cost increase. The proposed strategies for detection of issues and sensor fusion have been experimentally tested and validated in a real application scenario estimating the attitude of an AUV performing a lawn mower path.
The expected performance improvement is confirmed; the obtained results are described and analyzed in this paper.
}, keywords = {Robotics}, doi = {10.1109/TMECH.2016.2559941}, url = {http://ieeexplore.ieee.org/document/7460980/}, author = {R. Costanzi and F. Fanelli and N. Monni and A. Ridolfi and B. Allotta} } @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} }