Research On Simultaneous Stabilization Control Of Ship Dynamic Positioning

The dynamic positioning of ship refers to the device that the ship does not rely on the anchoring system,but relies on its own propulsion system to generate power to resist the impact of external marine environment interference,accurately positioning on the sea surface or following the preset path of navigation.In addition,the dynamic positioning system not only has the advantages of high positioning accuracy and strong maneuverability,but also has the characteristics of not limited by water depth and region.It is widely used in the application of rescue ship,supply ship,pipe laying ship,oil drilling platform and other marine engineering.At present,various researches on single dynamic positioning ship have achieved fruitful results,but the control of multiple ships has not made great progress.However,with the need of deep-sea exploration and exploitation,many scientific experts have turned their attention to the research on the control of multiple dynamic positioning ships.Compared with the operation of a single power positioning ship,the cooperative operation of multiple power positioning ships can not only improve the efficiency of offshore operation,but also make the ship have better adaptability and stronger robustness,especially suitable for ocean operation.In this paper,the problem of simultaneous stabilization control for two dynamic positioning ships is studied,some effective results of simultaneous stabilization control are given,which includes the following parts:1.Robust simultaneous stabilization of two dynamic positioning ship systems.The Hamilton function method is used to study the simultaneous stabilization and robust simultaneous stabilization of the system,and the corresponding simultaneous stabilization controller is designed.Firstly,the water surface three-degree-of-freedom ship model is transformed into the port-controlled Hamiltonian(PCH)model,and the general simultaneous stabilization conditions are given.Based on which,by adding the external interference,a robust simultaneous stabilization controller is designed.2.Adaptive robust simultaneous stabilization of two dynamic positioning ship systems.Firstly,the water surface three-degree-of-freedom ship model is transformed into a port-controlled Hamiltonian(PCH)model.Using a single output feedback controller,the two PCH systems are combined to generate an enhanced PCH system based on Hamiltonian structural attributes.Then,an adaptive robust output feedback controller is designed for the system with both external disturbance and structural parameter disturbance.3.By using the Simulink toolbox in MATLAB,the numerical simulation experiments of the dynamic positioning and stabilizing controller are carried out successively.Finally,the simulation results show that the designed controller has good control effect,meets the expected requirements,and accurately realizes the dynamic positioning of the ship.4.On this basis,an automatic cruise positioning ship system based on vision navigation is designed.The platform is mainly composed of ship body,main control unit,vision detection and ultrasonic obstacle avoidance unit.The main function of automatic cruise ship positioning system based on visual navigation is to detect whether there are obstacles in front of it,and then to navigate by ultrasonic avoidance and visual navigation,and finally to navigate and locate safely on the complex water surface.