Study On Passive Style Anti-pendulation Technology For Davit

The davit is offshore operations equipment which is used in the retractable boat. Its mission is to ensure the ship's boat and personnel quickly and safely put down to the surface, and the boats and personnel on the ship safely retracts Due to the influence of motion of the ship in abominable sea condition, the boat appears pendulating, the pendulation of the boat has become the bottleneck of safe and efficient system operation. Therefore, the anti-pendulation control of davit can greatly improve security and efficiency of offshore operations, the research has a great significance and in the civil and military areas.Aiming at the engineering application, the research is done on the passive style anti-pendulation of the davit in the paper. Firstly, structure and operational principle anti-pendulation system of the davit are analyzed. Dynamics mechanism of pendulation of davit system and basic principles of hydraulic damper device are studied. It provides a theoretical basis and technical basis for davit system dynamic modeling and design of passive style anti-pendulation system. Because motion of the ship is major cause of davit's pendulation, the ship motion response under the action of wave is analyzed. On this basis, the relation between the davit system and the ship swinging movement are abstained under the excitation of the ship rolling, pitching. Secondly,by using the Lagrange equation and its relational methods, the davit system's two degrees of freedom pendulum mathematical model is achieved. The simulation verifies the correctness of the mathematical model. The pendulum model which is analyzed, then it is reasonable to be simplified, a single degree of freedom dynamic model of the anti-pendulation device is achieved. The major factors affecting boat pendulation are analyzed, and then parameters of the anti-pendulation hydraulic damper device are designed. At the end, the virtual prototype model of davit system is achieved by the AMESim simulation software, and proves the effectiveness of passive style anti-pendulation system under different sea conditions. By changing the parameters of the ship and boat, the adaptable of anti-pendulation system is verified, and improving the method of adaptable of anti-pendulation system is given.Simulation studies of the paper show that the mathematical modeling and the anti-pendulation device which is designed is available in theory. The relational study contents of the paper are going to be used in relational engineering application.