Modeling and simulation of variable direction rotatable axis of variable vector propeller of submersible vehicle in vertical motion

Accurate modeling and simulation of submersible vehicle is essential for autonomous control and maneuverability research. In this paper, a variable direction rotatable axis of variable vector propeller (VDRA-VVP) is proposed and researched innovatively. The structure and working principle of VDRA-VVP of submersible vehicle are described and the nonlinear mathematic model of the submersible vehicle in spatial motion was derived based on momentum theorem. The forces acting on submersible vehicle were resolved to several modules which were expressed in matrix form. Based on the motion model and combined with three degrees of freedom model of vertical motion, a motion simulation system was constructed. Considering the characteristic of VDRA-VVP, the depth control and pitch angle control are simulated by adopting both robust PD control method and adaptive robust PD control method. The comparison result shows that the control effect of adaptive robust PD controller is obviously better than robust PD controller in vertical motion. The simulation results show that the VDRA-VVP of submersible vehicle has good spatial maneuverability, and verify the feasibility and reliability of control method.