Research On Control Of Trajectory Angle And Speed Of Air Cushion Vehicle

Air cushion vehicle(ACV)is quite different from ordinary surface ship.Due to lateral resistance,ordinary surface ship will not produce large side slip.There is no difference between bow control and speed direction control.ACV is prone to side drift due to its fast sailing speed,inertia force or wind disturbance,and its bow angle and trajectory angle are quite different.Therefore,it is very important to study the trajectory angle control of the ACV.Because the navigation of the ACV is greatly affected by external disturbances,the backstepping sliding mode control method is used to design the trajectory angle controller.This paper takes a certain type of the ACV as the research object,and studies the trajectory angle and speed control method of the ACV.The specific research contents are as follows:Firstly,the classification,working principle,hovering system and propulsion system of the ACV are introduced.The research status and development of hovercraft at home and abroad are introduced in detail.The related research and control methods of the ACV trajectory angle in recent years are also introduced.Secondly,the space motion coordinate system of the ACV is established.According to the theory of modular modeling,each module of the ACV is modeled separately.The force and moment of the ACV are synthesized in space.According to the momentum(moment)theorem,the kinematics model and dynamic model of the ACV are established,and the Four-Degree-of-Freedom mathematical model of the ACV is established.According to the established model,the direct and rotary characteristics of the ACV are simulated and validated.The simulation results verify the correctness of the model.Thirdly,the characteristics of the ACV propulsion system,RBF neural network and sliding mode variable structure control method are introduced.The sliding mode speed controller and RBF network sliding mode speed controller are designed and validated by simulation.The simulation results show that the control effect of sliding mode speed controller based on RBF network is better.Finally,the basic theory of backstepping control method and Lyapunov stability theory are introduced.According to the existing model,the trajectory angle controller of the ACV based on backstepping sliding mode is designed and verified by simulation.The simulation results show the stability,rapidity and robustness of the controller.The coordinated strategy of trajectory angle and velocity is studied,and the coordinated strategy is applied to the speed controller.The simulation results show that the coordinated speed controller reduces the sideslip angle of the ACV while the rotation rate changes slightly in the safe range.