Nonlinear adaptive ship course tracking control based on backstepping and Nussbaum gain

A nonlinear adaptive controller combining adaptive backstepping algorithm with Nussbaum gain technique is proposed for ship course tracking steering without a priori knowledge about the sign of control coefficient. It is theoretically proved that the presented adaptive controller guarantees that all signals in the uncertain nonlinear ship motion system is uniform bounded and the output of the controlled uncertain nonlinear ship motion system asymptotically tracks the output of the ship course reference model. The results of simulation for two ships´ steering models show that the designed controller can be properly adopted to the ship course tracking with good compatibility.