Research On Longitudinal Control Motion Simulation Of Supercavitating Vehicle Based On Three-dimensional Model

Supercavitation technology can reduce the friction resistance suffered by underwater vehicles and greatly improve the navigation speed of underwater vehicles.However,the biggest difference between supercavitation vehicles and conventional underwater vehicles is that supercavitation vehicles are wrapped in cavitation during navigation,which also makes them more difficult to control,especially when there are external disturbances,It brings great challenges to its dynamic modeling and stability control.The existing research on supercavitating vehicle is mostly carried out in an ideal environment.Therefore,this paper considers the interference of wave disturbance on supercavitating vehicle,and establishes athree-dimensional model of supercavitating vehicle for simulation verification.The main contents of this paper are as follows:Firstly,the research background,purpose and significance of this paper are briefly introduced,and the research status of supercavitating vehicle and control strategy at home and abroad is discussed and analyzed.Then two commonly used cavitation prediction models are studied.According to the configuration scheme of the vehicle,the force analysis of each part of the supercavitation vehicle is carried out in detail.The dynamic characteristics of the vehicle are studied on the appropriate coordinate system,and the nonlinear dynamic model and operational model are established.Secondly,some basic structures and actuators of supercavitating vehicle are briefly introduced.The three-dimensional model of supercavitating vehicle is drawn in the three-dimensional drawing software,and the simulation platform is set up.The three-dimensional simulation model of supercavitating vehicle is successfully imported and obtained.Then,based on the theories of hydrodynamics and Newton’s law,the mathematical model of longitudinal motion of supercavitating vehicle is established.The dynamic characteristics of supercavitating vehicle are analyzed.According to the results of dynamic characteristic analysis,the optimal controller of the longitudinal motion mathematical model of supercavitating vehicle is designed by using the dynamic inverse theory.The simulation results show that the controller realizes the depth control of supercavitating vehicle.Finally,in view of many complex uncertainties in the supercavitating vehicle model,these uncertainties are analyzed,and the perturbation problem of cavitation number caused by wave disturbance is proposed in this paper.On this basis,the sea wave is described and modeled,and the change value of cavitation number when the supercavitating vehicle encounters wave disturbance is calculated according to the definition of cavitation number.The simulation results show that the controller is not ideal for the cavitation number perturbation caused by wave disturbance.Next,the adaptive controller is used for compensation.The simulation results verify that the stability control effect of supercavitating vehicle is good.Then the three-dimensional model of supercavitating vehicle is simulated and verified.The results show that the designed controller can realize the simulation of supercavitating vehicle in three-dimensional space.