Path following control of underactuated surface vessels in the presence of multiple disturbances

— An integral version of the line-of-sight guidance method is shown to compensate for both kinematic and dynamic disturbances generated by wind, waves and sea currents. The guidance law is designed for path following tasks of underactuated marine vessels moving in the horizontal plane. Specifically, the control system consists of an integral line-ofsight heading reference generator in a cascaded configuration with an adaptive surge-yaw controller. The total drifting effect of the environmental disturbances is modeled as a combination of a constant and unknown kinematic drift, and a constant, unknown and heading-dependent dynamic pressure acting on the vessel. The closed loop stability analysis shows that path following is achieved with global κ-exponential stability properties. The theoretical results are supported by simulations.