Comparing Combinations of Linear and Nonlinear Feedback Terms for Motion Control of Marine Surface Vessels

:Nonlinear control algorithms are often designed with linear feedback terms. Such linear feedback typically gives rise to nice exponential stability properties, but are not physically realistic since all actuators have magnitude constraints. One way to address such constraints can be to introduce nonlinear feedback terms. Hence, this paper investigates combinations of linear and nonlinear feedback terms for pose and velocity control of marine surface vessels. Three cascaded controllers are developed and compared through three simulation scenarios and one model-scale experiment. The comparisons are made using performance metrics which consider both control accuracy and energy use.