작동기수가 부족한 자율무인잠수정의 안정한 추적제어

Abstract

In this paper, we propose a depth control scheme for underacutated AUVs where only the surge force and the pitch moment are available for vehicle's 3D vertical motion. Using certain two polar coordinates transformations, the AUV's dynamics can be reduced to a certain two-inputs-two-outputs (TITO) second-order nonlinear strict-feedback form. To avoid possible singularity problem in the recursive control design, in this paper we introduce a certain path re-planning scheme instead of taking the velocity term as a virtual control. Proposed scheme guarantees asymptotic stability of the position tracking error as well as the velocity and pitch angle tracking errors in the polar frame. The same asymptotic tracking property of velocity and pitch angle in the Cartesian frame is also discussed. Certain numerical simulation is also carried out to illustrate the effectiveness of the proposed scheme.