Research On Course Safety Control Method Of Air Cushion Vehicle

The air cushion vehicle(ACV)is a kind of using aerial propeller provides thrust,full hull supported by hydrostatic pressure's ship,in the process of sailing complete out of the water or ground,has an unique amphibious,seakeeping and high-speed navigation and so on,it has been widely used in the military and civil fields in various countries in the world.ACV compared with ordinary surface ships have a greater difference,ACV is easily disturbed by the external environment during its high-speed navigation,easily lead to a serious hull hump,resulting in buried and other dangerous situations;And when the hovercraft doing slewing motion,the centripetal force provided by the wave resistance due to suspended surface navigation is small,easy to cause side slip and drift,in the meantime,there is also the danger of capsize turning at large rudder angles;When traveling at low speed,the aerial rudder is less efficient,usually it is not possible to provide the torque required to change course,resulting in a large radius of gyration,a long time and other issues.In response to the above problems,in this paper,a type of ACV as a research object,a course control system based on disturbance observer is designed.At the same time,the safety navigation controller is designed under the premise of considering the heading safety of the hovercraft.First of all,adopt modular modeling ideas,according to a hovercraft experimental data,establish a mathematical model for each module in the coordinate system,then the force and torque of each module are integrated,by the theorem of momentum and moment of momentum given full mat hovercraft four degrees of freedom movement mathematical equation,switch to the motion coordinate system,finally,a 4-DOF simulation model is established,and simulation,in the absence of wind and wind conditions under different air hovercraft direct flight,slewing and other manipulation features into and out of the analysis and verification of the established hovercraft model.Secondly,combined with the characteristics of heading control,the theory of sliding mode variable structure control is studied,external disturbances are estimated by observer,a sliding mode controller based on disturbance observer is designed to solve the heading control problem.The strategy to control the chattering according to the common weakened sliding mode,observer-based sliding mode control algorithm combined with backstepping method,establish an improved course controller,and in different disturbance wind environment contrast verification.Then,aim at the safety control of the hovercraft course,the safety limits of the slip angle and the rotation law are established during the course of navigation,proposed the concept of track to indirect control,that is,the strategy of updating the desired direction based on the side slip angle information,non-singular fast terminal sliding mode control algorithm based on fast double power reversal law with variable coefficient design speed-track to Controller,and for a limited time to quickly converge and prove stability,ensure navigation stability and safety,achieve ACV speed-track to maintain control.Finally,the rudder propeller coordinated control allocation method is applied to the hovercraft and other speed-track to keep the safe sailing task.Through the simulation experiment,it is compared with the simulation results without coordination distribution,the simulation results show that the proposed method of rudder propeller coordinated control is safe,effective and fast.