Research On Multiple Models Control For The Heading Of Air Cushion Vehicle

As a high performance vehicle with unique navigation mechanism,Air cushion vehicle can break through some shortcomings of the conventional ships and works in some special conditions,this makes it widely used in many fields.Air cushion vehicle obtains the support from the air cushion on the bottom of the vehicle,so that the frictional resistance between the hull and the sailing surface is significantly reduced,however due to the lack of actuator to generate the centripetal force,so when the Air cushion vehicle is interfered by the external environment or happens inappropriate manipulation,it’s very easy to lead the serious side drift,buried bow,capsize and other accidents.Artificial control means is mainly used in the early time of the Air cushion vehicle control,this leads the drivers’ workload is very large,and they will bear a big pressure both on physical and mental.With the development of the technology,the research of the Air cushion vehicle automatic control also has developed quickly.However,because of the uncertainties of the Air cushion vehicle’s navigation,its motion has obvious nonlinear characteristics,and its hydrodynamic coefficient and aerodynamic coefficient change obviously under the high navigation state,so its control model will also change.The traditional control method which is designed by the single model is useful for the single operating mode but the control effect is worse when the working condition changes widely.So it is very necessary to study the multi-model control method of the Air cushion vehicle.The heading control of the Air cushion vehicle is the key to realize safe navigation of the Air cushion vehicle.Therefore,the multi-model control method is used to study the heading control of the Air cushion vehicle.First of all,a six-degree-of-freedom model of the Air cushion vehicle was established by establishing the model of each module of the Air cushion vehicle.Then,through the direct sailing experiment and the turning experiment,the model is validated.Then,based on the building method of the model set in the multi-model control,the model of the Air cushion vehicle is simplified and the model of the horizontal motion subsystem for the heading control of the Air cushion vehicle is obtained.On the basis of this,combined with the actual situation of hovercraft’s navigation,four models of the different working points which is divided by the longitudinal velocity of the Air cushion vehicle was selected to build the fixed model set.Then,based on the established local model,the sliding mode control theory was used to design the heading controller and constitute the controller set,and then a serious of simulation was done to verify the designed controllers’ performance.At last,as the fuzzy switching strategy is used in the Air cushion vehicle’s heading multi-model control,so the fuzzy knowledge and T-S fuzzy reasoning method are described in detail,and the fuzzy supervisor is designed to realize the switching of the model and controller.Finally,a multi-model heading control method based on fuzzy switching is designed,and through simulation and comparison with a single model,the effectiveness of the designed multi-model heading control method is validated.