Disturbance observer based tracking controller for an autonomous underwater vehicle

The problem of trajectory tracking of an AUV in the presence of time varying external forces has been considered in this paper. A nonlinear disturbance observer has been designed to estimate the disturbance generated from an exogeneous system. Exponential convergence of the estimated disturbance and the actual disturbance has been proved. Furthermore asymptotic stability condition for composite tracking controller with disturbance observer is presented in this paper. The simulation results prove the efficacy of the proposed controller.