Simulator and Control System Design for a Free Floating Surface Effect Ship at Zero Vessel Speed

This paper covers vertical motion damping of a free floating Surface Effect Ship (SES) at zero vessel speed. Vertical motion damping is requested at the bow deck of the SES during offshore wind turbine docking operation. Vertical motion damping provides a safer transfer of personnel and goods from vessel to the wind mill in moderate/rough sea states. This will provide an increased operational weather window access for maintenance and repair. The paper has two main contributions. 1) A simulator model for a SES. This is referred to as the cushion process plant model and provides a valid simulation tool for the control system. 2) A simple controller for actuating air cushion pressure. The presented controller actively controls the air flow actuators to the air cushion in order to minimize vertical motions at the vessel bow. A numerical stability investigation for the controller is included