|
Air Cushion Vehicle has high-performance which is supported by the static air pressurebelow the vessel. The ship was lifted by lift system, thrust by high-power propellers whichware installed on the tail of the ship, controlled by air rudder. Fans supply gas to the airchamber under the boat. The vessel floats out of the water or the ground completely supportedby the air-cushion, running at a high speed above the water or the land.Hovercraft hydrodynamic resistance is smaller relative to a surface ship, sailing bywave interference effect. There existed a phenomenon that “sailing at high speed easy lead tobow, low speed easy lead to capsize”. The main influence to hovercraft is marine environment.When the hovercraft sailed at a high speed, the tailwind can easily lead the boat bow underthe aerodynamic effect. If giving a larger rudder angle, it can easily appeared high speed driftphenomenon. When the hovercraft sailing on a low-speed, the ship can easily sideslip whensteering, the reason is that smaller yaw damper and external aerodynamic centripetal force isnot enough. These features of the hovercraft decided it’s security is poor, not easy tomanipulate, At present, the hovercraft in domestic is mainly rely on manual operation, thedriver in the driving pressure, heavy workload, is prone to operator error. Coastalminesweeping, anti-submarine, port and dock, task, the operation precision is high, themanual operation can not be accurately completed. And the safety of navigation is hovercraftto complete the operation and function of the security. In order to reduce the driver’s burden,improve safety movement, and improve the control effect, researching on the motion controland safety navigation of the hovercraft is necessary.In this paper, we mainly research a hovercraft’s safe navigation control problems,Establish modeling and analysis its stability based on a certain type of hovercraft, research airrudder and the rotating nozzle coordination control lastly. The specific contents are asfollows:Firstly, establish the mathematical model which is the six degrees of freedom motion ofAir Cushion Vehicle. Research various resistance and model them separately, includingaerodynamic, hydrodynamic and air-cushion power model; analysis of the handlingcharacteristics of the implementing agencies, including rotating nozzle, propeller, air rudder,side door. We establish the entire motion model complete and did simulation experiments tovalidate the model.Secondly, we study the variable structure control theory, design heading sliding mode controller to solve hovercraft course control problem. Improving the course controller designbased on common weaken variable structure control the buffeting strategy, research theback-stepping combined variable structure control method. At last giving simulationscomparing the role of disturbance wind.Then, we research the safe navigation of the hovercraft, establish hovercraft parametersof security clearance during the navigation process. Based on the stability requirementsanalysis the heading control needs, focuses on the lateral stability of the hovercraft. In orderto improve transverse stability, we research the heeling movement control. Including theproperties of rotating nozzle manipulation, according to the hovercraft model simplification,we get the heeling motion model and design the heeling controller using back-steppingmethod.Finally, in order to coordinate two subsystems, under the coordination method, we designcoordination controller to track motion and heeling movement. under different environmentalwind interference simulation were designed to verify the effectiveness and superiority ofcoordinated controller.
|