VESSEL MOTION CONTROL DURING ROLLING BASED ON FUZZY LOGIC

Abstract

Among the many factors affecting a vessel's performance is pitching, which is caused by external factors such as sea waves, wind, currents. This significantly increases resistance to the vessel's motion, leading to increased energy consumption for the propulsion system. Incorrect operation of the propulsion system itself may also occur, and a negative impact on the human vestibular system has been observed. Using storm diagrams for navigation areas is not always able to eliminate the negative impact of pitching on a vessel's motion.
This paper analyzes the primary means of mitigating the negative impact of pitching on a vessel's seaworthiness. It emphasizes that initial methods of stabilizing a vessel's motion are standardized at the design stage, when developing a cargo plan and reducing the waterline area.
The main types of stabilizers used in shipping are discussed. These include bilge keels, rudders, and gyroscopes. Particular attention is paid to the use of active and passive stabilizers, as the movement of water masses in these tanks can alter the vessel's heel angle and oscillation frequency during rolling.However, the use of passive tanks is limited, as they are effective only during resonant roll.
Active tanks are the most promising stabilizers, but their effective operation requires the implementation of a complex control system that must quickly respond to external disturbances.
In this paper, a mathematical model for controlling the operation of active tanks on a ship, which are used as stabilizers, is developed. This model utilizes fuzzy logic tools in Matlab Simulink with the Fuzzy Logic Toolbox extension. The study presents membership functions for input and output linguistic variables. The input linguistic variables are the bank angle, the direction of the bank angle vector, and the angular velocity. The initial linguistic variable is the opening degree of the compressor valves used to pump water between the tanks.