Finite-time path following control of unmanned surface vessels with an obstacle avoidance strategy

This paper addresses the finite-time multilinear path following problem for unmanned surface vessels, where external disturbances, input constraints, and statically known obstacles are considered. Specifically, a finite-time observer designed based on finite-time theory is first used to repair the unknown lumped disturbance and then compensated into the controller. Then, the finite-time line of sight is applied to the linear path-following problem. Next, a finite-time sliding mode control is designed at the dynamics level to achieve finite-time convergence of the dynamics errors. Finally, a simple and intuitive obstacle avoidance strategy based on geometric relations is designed, considering the possible presence of static obstacles in the following. Theoretical proofs and a simulation case are given to illustrate the validity of the proposed scheme.