Design of an Underwater Vehicle for Adjusting Course by a Rudder Control Strategy

Most underwater vehicles (UV) adjust their attitude depending on the direct thrust of their propellers at different parts or change their course through the rudder during moving at high speed. However, it is hard for the rudder to function at a low speed. This paper introduces the design and control of a UV that can work at various speeds, including the structure design and control method. This UV can adjust the attitude with three rudders. The top rudder controls the left-right heading in high-speed motion. The left and right rudders have two degrees of freedom (DOF), respectively, and the twisting degree of freedom, the same as the conventional rudder, is used to control the ascent and descent during high-speed motion. The unique feature is that the flapping degree of freedom allows the UV to adjust its heading at low speed or hovering, which is challenging with the conventional rudder control method. In this paper, we design an experiment to verify the function of the flapping steering, and the result shows the scheme’s feasibility.