Abstract:During the sailing of supercavitation vehicle, the tail will periodically beat the cavitation wall and show a strong "tail-beating" phenomenon. The tail of cavitation is formed by the historical position experienced by the supercavitation vehicle and presents a strong time-delay characteristic. Dynamic modeling and stability control are the core problems restricting its development. Aiming at the cavitation-body coupling problem, the dynamic model of the integrated real time solution of the relative geometry relationship between the cavitation and rigid body is established. Aiming at the nonlinear characteristics, the piecewise linearization method is used to establish a simplified control oriented model while preserving the nonlinear characteristics of the rear body tail beat. In order to solve the nonlinear time-delay control problem of supercavitation vehicle, the control model is configured to the ideal state by pole assignment in view of the characteristics of extremely sensitive movement and high control efficiency. A perturbation-oriented variable structure controller (VSC) was established to control the disturbance motion of the supercavitation vehicle due to the nonlinear and uncertain process. The control law of roll channel and pitch channel is designed by pole assignment variable structure control method. The simulation of 6DOF control closed-loop trajectory using the cavitation-body coupled dynamics model shows that the depth control error is less than 0.1m and the roll Angle control error is less than 4° during the stable cruise. The proposed control method can achieve stable control of the roll Angle and depth of the vehicle. The control effect is good and can meet the navigation requirements of the supercavitation vehicle.
