Research On Integrated Balance System For Large Navy Ships

The integrated balance system for large navy ships is a new subject in controlling of ship's pose. The navy ship, as a movable fighting platform, needs better integrated balance than normal ships. The subject mainly talks about the integrated balance system which combined with fin stabilizer, anti-roll tank and anti-heel tank. The integrated balance system for large navy ships can reduce the ship roll effectively under mooring and seaway conditions. It can also make up the ship heel because of the loads, the damage of the ship's hull and the wind pressure. The better condition for designing the integrated balance system will be created through the research.The dissertation, based on the national defense program "Research on the integrated balance system for large navy ships" in the Tenth five-year project, is mainly studying the method of the integrated balance system for large navy ships.The dissertation analyses the characters of fin stabilizer and anti-roll tank and introduce the development and research of the integrated balance system in foreign countries. Then an integrated anti-roll method, combined with fin stabilizer and anti-roll tank, is proposed to reduce the roll of the large navy ships.According to Lagrange dynamical equation and Kriloff theory, the mathematical model of integrated anti-roll system "ship -fin stabilizer-passive anti-roll tank" is built up. The anti-roll capability of the integrated anti-roll system and the relationship between the fin stabilizer and anti-roll tank is analyzed based on the mathematical model.The integrated anti-roll control system is established based on the "ship -fin stabilizer-passive anti-roll tank" mathematical model. After discussing the fitting method of fin stabilizer and anti-roll tank and analyzing the design method of "U-type" passive anti-roll tank, an fitting method of the integrated anti-roll system was proposed basing on the economical factor and the anti-roll capability of the system finally.According to the optimal control theory and considering the practicability of the system, genetic algorithm is used to optimize the parameters of the PID controller. The simulation was done based on a ship data, the results show that theintegrated anti-roll system has the advantages of the fin stabilizer and passive anti-roll tank, the anti-roll system has better anti-roll capability under different encountering wave directions and ship speeds. The integrated anti-roll system, combined with fin stabilizer , anti-roll tank and anti-heel tank, can reduce the large navy ships' roll under complex sea condition and ship speeds.According to the function of the integrated balance system, a combining method of the integrated balance system was proposed. Using time domain theory to compute the ship roll motion under the irregular external force moment during loading and unloading. The ship roll and the working of the anti-heel system was simulated during loading and unloading; because the navy ships need higher anti-sink quality, a mathematical ship-roll model, combined with the theory of the flume anti-roll tank, is built up when the ship's hull was damaged, then the dissertation discusses the ship roll and its balance when the ship's hull was damaged.The subject, which is formed based on the present researches of fin stabilizer and anti-roll tank in China, has a good applied future.