3d Path Tracking Of Under Actuated Auvs With General Form Of Dynamics

This paper proposes a 3D path tracking method for a class of torpedo-type AUVs ( autonomous underwater vehicles) with general form of dynamics. For this kind of AUV, there are only three control inputs are available for its 6DOF 3D motion, and therefore it's a typical underactuated system. First, we introduce certain two spherical coordinate transformations so as to transform the vehicle model into three-inputs-three-outputs second-order strict-feedback form. To avoid possible singularity problem in the recursive control design, an asymptotic modification of orientation concept is introduced. Proposed tracking scheme can guarantee the asymptotic stability of closed-loop system in the spherical coordinate frames.