Incremental Gain Scheduling and Sensitivity-Based Control for Underactuated Ships

Maneuvering of ships in difficult situations is one of the main tasks in maritime and inland navigation. To increase the operational capacity in water transport as well as to improve its reliability and safety, new control strategies are required. Besides the optimization of parameters of existing control approaches, it is necessary to develop new techniques which are applicable to robust velocity control and path following. For that purpose, novel techniques for incremental gain scheduling in nonlinear control systems as well as for sensitivity-based feedforward control are summarized in this paper. Numerical simulation results are presented to highlight the applicability of the presented approaches in a basic control structure for path and trajectory following with and without underlying velocity control. Possible application scenarios of the presented techniques include the automatized navigation of ships, the avoidance of collisions by evading oncoming vessels, the assistance of captains during both steering in critical route segments and piloting of ships into ports, as well as offline path planning.