Rudder roll stabilization and ship design: a control point of view

A recent result in the field of ship control systems is an autopilot which uses the rudder not only to control the heading of the ship but to reduce the roll motions as well. This rudder roll stabilization (RRS) autopilot is to be installed on board the new M-class frigates of the Royal Netherlands Navy. One of the objectives of the research on this RRS autopilot was to investigate what modifications in a ship design are required to enable a successful application of an RRS system. The paper presents several requirements on the ship design to enable a substantial roll reduction. The most important design parameters are the maximum rudder speed and the influence of the rudder on the roll motions. If the rudder has a large influence on the roll motions, it has a large roll-reduction potential as well. The rudder speed should be sufficiently high to enable a large roll moment around the natural roll frequency of the ship