Research on control method of AUV terminal sliding mode variable structure

Due to the large range of dynamic parameters during the Autonomous Underwater Vehicle (AUV) navigation process, the AUV control system exhibits strong non-linear characteristics. Therefore, it has strong requirements on the control performance. For normal sliding mode control, however, the state tracking error does not converge to zero over a finite time. Aiming at dealing with the nonlinear AUV control problem with variable parameters, a Terminal sliding mode variable structure control system with fast convergence speed, high control precision and strong robustness is designed. In this method, firstly, the AUV kinematics and dynamics model are established, and the equations of heading motion and longitudinal motion are described respectively, and the linearization is carried out. Secondly, the sliding mode motion switching function is introduced, and the longitudinal port sliding mode controller is designed respectively. The whole process of the control system from the initial state to the equilibrium state is robust to the disturbancs. Finally, the Lyapunov function is used to verify that the dynamic error has global asymptotic stability. The simulation results show the effectiveness of the control method and confirm the correctness of the theoretical analysis.