Research On Path Following Control Method Of Air Cushion Vehicle

As a high performance vessel,Air cushion vehicle(ACV)use air rudder and air propeller as operating device is supplied by static pressure through replenishing the air into cushion apron.Due to well performed in amphibition and rapidity,the ACV can sail rapidly in special environments.Therefore,the ACV has broad development prospects and application needs.Compared with the conventional surface ship,the ACV always sail surface on the water which cause lack of underwater rotating components.During the path following,the ACV may drift with lack of underwater rotating components providing sufficient turning force,which even causes accidents when it is serious.Therefore,it is necessary to design a safe and reliable path following control system.The paper aiming at path-following,the core of the ACV,take the basic model and verification analysis,plan the path in the case of obstacles,guide the navigation path,and design the path following control method.The specific work as the following four aspects:Firstly,in order to meet the needs of path following research,using the idea of modular modeling,the ACV components are deeply analyzed and modeled.According to the mechanics principle,modules such as aerodynamics,hydrodynamics,propellers and air rudders are vector synthesized.Therefore,a mathematical model of four-degree-of-freedom motion can be established.In addition,a sea breeze module is established to introduce environmental disturbances and simulate actual sea conditions.At last,the maneuverability simulation experiment is carried out to verify the correctness.Secondly,aiming at the ACV path planning problem,the Dijkstra algorithm principle is introduced.Through analyzing the Dijkstra algorithm advantages and disadvantages,the Dijkstra algorithm based on ant colony is designed to plan path with obstacles presence.Thirdly,aiming at accurately following path guidance problem,based on the given planning path,a series of improvements are made to the LOS guidance law,which solves the problem of guiding radius selection.According to this,a forward line of sight guidance method is proposed.Based on the controller designed by sliding mode method,the proposed forward-looking LOS guidance method is simulated and verified,and the follow-up of the planning path is realized.Finally,the path follower controller design method is deeply studied.In view of the problem of buffeting and fastness of the sliding mode method,the non-singular fast terminal sliding mode method is introduced,which realizes the fast convergence of the track to the planning path in a limited time.Aiming at the actual situation of ACV maritime navigation,in the case of sea breeze interference,combined with the disturbance observer,a non-singular fast terminal sliding mode method based on disturbance observer is proposed,which realizes effective observation compensation for external disturbance.The Lyapunov stability theory verifies the stability of the proposed method and ensures the rationality of the design.