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

(AUV) applications. This paper presents the 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 need 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. In a first time, we have an initialization phase which is necessary to obtain an initial estimate of the vehicle's location with respect to a fixed or moving beacon. These initials 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 present also post-processing results in comparison with LBL navigation and mission experimentation post-processing treatment. And then we applied our method for two vehicles operations. I INTRODUCTION Actually, there is a real challenge on application of Autonomous Underwater Vehicle, particularly for offshore industry, marine laboratory or military operation in bathymetry exploration, pipeline verification, environmental measurements or minefield detection. Instead of realizing many missions with one AUV, the future is to plan one mission with a flotilla. In some cases, more sophisticated capabilities such as homing and docking are required. For the long term deployment of AUVs (Autonomous Ocean Sampling Network concept), the vehicles must be capable of returning to their moorings for recharging battery, data downloading and mission programming. Many different approaches have then been implemented and tested based on acoustic (Ultra Short Base Line, Short Base Line and Long Base Line system), electromagnetic or optical sensors. Long baseline navigation systems have generally been used for positioning of underwater equipment and manned submersibles, and more recently for navigation of Autonomous underwater vehicles [1][2][3][4]. Although, these systems can offer a good positioning accuracy, provided the array is correctly calibrated, they also have several drawbacks. The deployment and the recovery of the transponders as well as the calibration of the array are ship-time consuming and therefore expensive. Furthermore, the whole process has to be repeated each time the array is moved to a different place. The overall cost of the …