Robust Output Feedback Control Design for a Class of AUVs

Abstract

In this paper, a robust output feedback stabilization for a class of Autonomous Underwater Vehicle (AUV) is investigated. Two cases for, nonlinear, decoupled equations of motion of AUV in steering plane are considered in this work. In the first scenario, where all states are measurable, semi-global asymptotic stability for a class of AUV is shown by proposing a state-feedback controller based on Sliding Mode Control (SMC). The stability analysis is evaluated under model uncertainties and parametric variations. Then for the second case, Extended High-Gain Observer (EHGO), augmented with Extended Kalman Filter (EKF) is used to estimate the immeasurable states. It is shown that the states of the closed-loop system with output feedback controller, approach the invariant manifold in finite time and stay there. Efficacy of the proposed controllers is demonstrated with the help of numerical simulations.