Research On Maneuverability Characters And Course Control Method For Large-scale Air Cushion Vehicle

Air cushion vehicle (ACV) is supported by the air pressure, used air propellers to provide thrust, completely out of the water when sailing with small water resistance than the ordinary vehicle. It is one typical kind of the clipper vehicles with good seakeeping and amphibians.Because of the special status of sailing, it is more sensitive to the external environment,when there is wind disturbance will cause the hull side leakage, heeling, obsessed and other dangerous situations; and when the ACV do rotary movement, hovercraft rely on air rudders to finish the task. But air rudders can't produce enough centripetal force, there will be serious skid, drift. Since it is a danger of capsizing may occur when a large steering angle rotation.The emergence of these problems, it is due to the special structure of ACV caused relatively poor maneuverability. To develop the maneuverability, internal and abroad specialists began to drive integrated control system to the control of the ACV. Automatic sailing control can reduce driver's stress and enhance safety of navigation. For the poor maneuverability problems of air cushion vehicle, the paper gives the research of maneuverability simulation analysis and course control.In this paper, large-scale air cushion vehicle is the mainly research object, small ACV has been used widely. Large ACV has good prospects in both passenger and military.Specific work as follows:Firstly, based on the data of the experiments and the parameters of implementing agencies in a certain type of ACV, each module for modeling is obtained. Each of modules is deduced by Newton's law of force, so a four-DOF motion mathematical model of ACV is established.Secondly, research on the maneuverability of the implementing agencies. With the conditions of all kinds of wind, we finish the simulation analysis such as direct sailing,rotation, back straight, and Z-shaped motion, which meet the sailing properties of ACV.Thirdly, for the realization of course control, the theory of sliding mode control is introduced and chosen to design the course controller. Sliding mode control have the weakness of vibration. It produces great effect on the stability and precision. In order to reduce the vibration and improve the adaptability of control system, fuzzy control and neural network control are combined with sliding mode. A fuzzy sliding mode controller and neural network sliding mode controller are used in the course control of ACV respectively. We compared with ordinary sliding mode simulation to show the perfect performance.Finally, considering the security of course control process, the analysis of the safety of navigation is completed on the limits of the slew rate and side-slip angle. The switch control of course and slew-rate control is introduced to keep the slew rate and side-slip angle in the safe range. Simulations show that this design has a good effect. switch control can avoid too large angle of slew rate and sideslip due to the rotary movement and flick overturning and other accidents.