D1.3 AutoDrop hull and rudder functional description

The AUTODROP model is designed to be dropped out of a ship and be able to manoeuvre autonomously to a fixed point with small uncertainty. During navigation, two phases can be identified: dropping phase and slow down one. The first lasts the great part of falling time and the task is to reach the desired location, the second is the landing, when the model has to reduce its speed, keep the right direction to the target and perform several operations, like unfolding the legs,before touching the seabed. A preliminary estimation of body's and rudder's hydrodynamic forces and moments during a general motion have been computed in order to design, develop and test the Guidance Control System. Body's behaviour has been estimated using a mathematical modelling approach whereas rudder's lift and drag coefficients have been obtained after a data acquisition session on a 1:1 rudder model performed at INSEAN-CNR towing tank.