|T3.3.1 Intelligent AUV mapping|
|T3.3.2 AUV-ASV Cooperation|
M6-M42. The goal is to locate an AUV with the help of the ASV whose position
is well known thanks to its GPS and AHRS units.
USBL Navigation (Ultra-Short Base Line): The surface vehicle will be equipped with an USBL transceiver able to simultaneously locate the AUV (equipped with an acoustic modem able to perform as an USBL transponder) in spherical coordinates (slant range, bearing and slant angles). Next, the ASV position, as well as the AUV relative position with respect to it, will be broadcast over the acoustic modem. The AUV, will receive the ASV position, its own ASV-relative position and it will estimate its own position. Therefore, the outcome of this cooperative navigation system will be that the involved vehicles will be aware of their own position as well as the position of the other of members of the robotic team.
Range Only Navigation: Here, the use of a commercial low-cost ASV will be evaluated, such as the WavegliderTM powered by renewable energy for the acoustic positioning and communication with a deep-sea AUV (3000m depth). The comparison of integration projects for deep ocean USBL systems and for a synthetic (1 range-meter) long baseline system on the ASV will be assessed. For the latter case, the ASV will be required to move along a trajectory that is optimized for the observation of the vehicle transponder under varying geometric view angles allowing to determine the AUVs absolute location. Strategies to optimise the ASV trajectory will be elaborated with respect to the potential of the produced range-data set; in this sense the control algorithm will synchronize the ASV and AUV missions. The modelling of acoustic transmission characteristics will be used in an online estimator in order to estimate ranging reliability and accuracy. These parameters will then be fed back to the trajectory control algorithms.