Advanced path-following control of unmanned surface vessels using fully actuated system theory

This paper proposes a novel cascaded path-following control architecture for unmanned surface vessels. By utilizing fully actuated system theory as a dynamic linearization interface, the inner loop transforms underactuated dynamics into a decoupled fully actuated form. This approach guarantees precise tracking without introducing excessive design complexity. An extended line-of-sight guidance law with time-varying look-ahead distance is integrated to compensate for unknown drift. Furthermore, a composite Lyapunov analysis rigorously proves the uniform ultimate boundedness of the closed-loop system, explicitly accounting for coupling effects. Simulations demonstrate superior tracking accuracy, convergence speed, and robustness compared to existing nonlinear methods. The limitations related to parameter-dependent compensation and actuator constraints are also discussed as future extensions toward adaptive fully actuated system–extended line-of-sight control.