Estimativa de perturbações e controle por modo deslizante adaptativo de uma embarcação teleoperada

Abstract

This dissertation applies Adaptive Sliding-Mode Control (SMC) algorithms to a teleoperated vessel operating in a pool in the presence of disturbances. It is a challenge to estimate the disturbances caused by winds, waves and currents, in addition to modeling uncertainties, since there is no possibility of measuring them in the laboratory. The disturbance estimates were also used in one of the adaptive algorithms used in this dissertation. In order to develop the vessel control, first of all, the dynamics of surface vessels with three degrees of freedom are modeled. Then, the trajectory planning is discussed in order to parameterize the trajectory to be followed by the boat. Next, a nonlinear dynamic can be simplified into a linear one by applying feedback linearization. Adaptive Sliding-Mode Control Algorithms are proposed and their advantages and disadvantages are discussed. Performance assessments are carried out with simulations and experimentally verified with the aid of a visual motion capture system, acting as a position and orientation sensor for the boat. Proportional-Derivative (PD) and Proportional-Integrative- Derivative (PID) controllers are also used for comparison with the proposed SMC algorithms.