Simulation results, post-processing experimentations and comparisons results for navigation, homing and multiple vehicles operations with a new positioning method using on transponder

Homing and navigation capabilities are essential for many autonomous underwater vehicle (AUV) applications. This paper presents both problems with respect to a single beacon and an extension of the method for multiple AUV operation using relative location. The difficulties of this approach are due to the fact that a single range measurement does not completely constrain the beacon´s position in the vehicle frame. In order to triangulate his position, the AUV needs to maneuver while measuring its displacements between ranges. In addition, range measurements are noisy and sometimes spurious, speed bias and underwater currents affect dead-reckoning measurements. All operation need to have the same beginning. An initialization phase is necessary to obtain an initial estimate of the vehicle´s location with respect to a fixed or moving beacon. These initial estimates are refined during the actual displacement towards the beacon by means of a Kalman filter. Two kinds of navigation are used so as to maximize the information matrix and to maintain an accurate absolute position. We also present post-processing results in comparison with LBL navigation and mission experimentation post-processing treatment. And then we applied our method for two vehicles operation.