Mitsui Advanced Rudder Roll Control System (MARCS)
The Mitsui Advanced Rudder Roll Control System (MARCS) is a roll control system used to reduce the ship's roll motion by rudder developed by Mitsui Engineering & Shipbuilding Co., Ltd. This system controls heading and roll motion of the vessel in good balance on the basis of the latest control theory, applying Multi-variate Auto-regressive model and optimum control theory.
MARCS inputs signals of heading angle, roll rate and rudder angle response and outputs rudder angle order to the rudder control system. The features of this system are briefly outlined below.
(1) Rolling reduction control can be done practically without adversely by affecting the course keeping of the ship.
(2) The system, composed only of a control unit that incorporates an I/O interface and a roll rate sensor that detects roll rate of the ship, and an operation panel is small in size and does not require much space for installation.
(3) Since the system utilizes the normal rudder for navigation, it can be easily installed on virtually any type of ship regardless of whether it is an existing ship or newbuiling.
(4) The system is much smaller and lower in price than fin stabilizers or anti-rolling water tanks.
(5) It is possible to use the system concurrently with fin stabilizers or anti-rolling water tanks.
This system has been installed on university training ships, fishery research ships and other special purpose vessels, and its performance has been clearly demonstrated. The anti-rolling effectiveness of the system deffers depending upon the type of rudder used, the speed of the movement of the rudder, sea conditions, and so on. However, an improvement in anti-rolling effect of 30〜40% or more can be expected in the case of this system compared with that of conventional automatic steering equipment.
A combined effect can be obtained by using the system together with fin stabilizers and anti-rolling tanks. This being said, however, this system will exhibit its best performance when it is installed on small or medium size vessels, cargo ships and ferries that are not provided with these anti-rolling devices.
