Dynamic Control of an Underwater Vehicle near Wave Surface

The dynamic control of an underwater vehicle near wave surface is dealt with in order to resolve the crucial weakness of the motion of an underwater vehicle in such situation. For the sake of dynamic modeling of surface wave disturbances, first, a simple model of a commercial autonomous underwater vehicle is considered. Next, wave forces and wave moments per unit wave amplitude depending on wave frequency, wave direction, and operating depth are calculated using numerical analysis software, ANSYS AQWA. Then, sparse numerical results of wave forces and wave moments are interpolated numerically to use in continuous cases for wave frequency, wave direction, and operating depth. The results of numerical interpolation for wave force and moment are used in making dynamic wave modeling equations and for wave disturbances in dynamic simulation. Then, dynamic characteristics of underwater vehicle is analyzed and the dynamic relations between wave force and dynamic control inputs are investigated. The results of dynamic control with the uses of control fins and a thruster in wave have shown useful to analyze the underwater vehicle's motion characteristics near wave surface.