Autonomous fast ship physical model with actuators for 6DOF motion smoothing experiments

This paper describes a new experimental system that has been recently developed for a research on vertical motion alleviation of fast ferries. The case of a fast ferry with a pair of transom flaps, lateral fins and a T-foil is considered. All these actuators should be moved in the most effective way, and an appropriate control strategy must be obtained and tested. A scaled physical model of the fast ferry has been built, with moving actuators and a distributed monitoring and control system. The research considers 6DOF motion attenuation, for any ship's heading. For this scenario, an autonomous physical model, not to be towed, is required. The physical model includes two scaled waterjets, with the jet orientation under control. The ship has no rudder. Heading and motion alleviation control includes many sensors and actuators. As a good practical control solution, a distributed architecture based on the CANbus has been devised. There is a set of microcontrollers and an embedded PC as coordinator. The microcontrollers for the actuators simulate the time behaviour of hydraulic cylinders. The microcontrollers for sensors include signal conditioning functions. There is a digital radio communication with an off-shore monitoring system. The off-shore system can display the present and the recorded experiments with animated 3D graphics. The complete experimental platform can be used as an Internet laboratory. The system can be easily tailored for use in real ships.