Towing And Winch Control Strategy For Underwater Vehicles In Sheared Currents

TLDR: In this paper, an efficient approach for planning towing maneuvers for an underwater vehicle via ship and winch control is presented, which relies on the fact that the system is differentially flat under certain modeling assumptions; hence, it is possible to determine the required ship motion and the winch rate so that the specified trajectory of the submersible is followed.

Abstract: An efficient approach for planning towing maneuvers for an underwater vehicle via ship and winch control is presented. It is demonstrated that it is possible to generate a towing strategy for a submersible vehicle such that the towed body follows a desired trajectory in the presence of known currents. The approach relies on the fact that the system is differentially flat under certain modeling assumptions; hence, it is possible to determine the required ship motion and winch rate so that the specified trajectory of the submersible is followed. The cable is modeled using a lumped mass approximation, including hydrodynamic drag, buoyancy and added mass effects. In the proposed approach, extensive use is made of spectral collocation methods to compute derivatives of motion. The approach is capable of producing open-loop trajectories in very short computation times, which makes it suitable for real-time computation.