Research On Stability Of Offshore Approach Bridge Platform Based On Anti-Rolling Gyro

As an important ship facility,the stabilized platform is of great significance for ensuring maritime rescue.The traditional marine motion compensation platform monitors the ship’s motion status through sensors and feeds it back to the control system.Because this technical means requires a period of time to convert the monitoring signal into a control signal,there is a certain delay,which causes the motion compensation of the platform to lag.Passive compensation method.In order to overcome the shortcomings of passive compensation,this thesis studies an offshore stabilized platform system with active wave compensation capability.The anti-rolling gyroscope is installed on the stabilized platform,and the anti-rolling characteristics of the gyro anti-rolling device are used to achieve active anti-rolling of the platform.The research content of this thesis is as follows:First,the basic principles of rigid body kinematics and dynamics are described.According to the transformation coordinates and the theorem of moment of momentum,a dynamic model of a single frame control moment gyroscope is established.Then,the motion equation of ship rolling is established based on the principle of moment balance.It is found that in the full-system coupling model of wave-ship-gyro stabilizer,its anti-rolling effect is mainly achieved by the solid-solid coupling between the gyro stabilizer rotor and the ship and the fluid-solid coupling between the wave and the ship.Establish a mathematical model of ship rolling motion including gyro stabilizer.Then,take the 2000 horsepower sea rescue tug as the research object,establish the rescue tug calculation model,use the CFD software STAR-CCM+,use the overlapping grid technology and the DFBI motion solver to numerically simulate the six-degree-of-freedom motion of the ship under the action of waves,and calculate them separately The roll amplitude of the tugboat under different wave parameters is found,which lays the foundation for the co-simulation of the following six-degree-of-freedom compensation platform.After,according to the design requirements,the structural parameters of the Stewart platform and the gyro anti-rolling device are determined,and the three-dimensional modeling is carried out based on Solidworks,and the dynamic analysis of the Stewart platform considering the damping term is carried out.Then,by consulting the relevant information about the offshore approach device,comparing and analyzing the different structure types of the gangway,a truss structure telescopic gangway with strong bearing capacity and simple structure is designed,and a slewing device and a stretching device are designed to adjust the horizontal angle of the gangway.And pitch angle to meet the needs of different working conditions.Finally,the STAR-CCM+ software is used to establish a numerical model of the stabilized gyro-based offshore platform under the wave motion of the ship.The effects of the speed of the gyro rotor and different wave parameters on the anti-roll performance of the gyro are studied by numerical simulation.By comparing the roll amplitude of the upper platform before and after anti-rolling,it is verified that the designed stable platform has sufficient active compensation capability and excellent anti-rolling performance.