Designing Optimal Trajectories and Tracking Controller for Unmanned Underwater Vehicles

Abstract

In this paper, we present the designing optimal trajectories and a tracking controller for the depth control of an unmanned underwater vehicle (UUV). These optimal trajectories are explicit functions derived from solving analytically the nonlinear second order differential equation representing the depth motion of the vehicle. In order to control the depth motion of UUV under disturbance effects and uncertainties of system, a sliding mode controller is proposed. By applying this proposed control scheme to uncertain linear time-varying second order system of UUV depth motion, the shortest travel time or minimum energy consumption maneuver are expressed in a closed-form equation if ranges of parametric uncertainties, torque limits, and reference inputs are specified. To support the validity of the analyses, we perform the computer simulation using this approach. Through the simulation results, effectiveness and robustness of the approach was demonstrated even with uncertainties.