Experimental study of adaptive course controllers with nonlinear modulators for surface ships in shallow water.

The present paper proposes a new adaptive controller with nonlinear modulators to improve the controller adaptability and rudder efficiency so that a satisfactory course tracking performance of ships can be achieved. First, a new adaptive control law on basis of Internal Model Control (IMC) is designed to address the speed dependency of the controller. Three types of nonlinear modulators are then added to the developed adaptive controller to increase the rudder efficiency.

Development of an upwind sailing ergometer.

Purpose: To develop a sailing ergometer that accurately simulates upwind sailing exercise.

Methods: A sailing ergometer that measures roll moment accompanied by a biofeedback system that allows imposing a certain quasi-isometric upwind sailing protocol (ie, 18 bouts of 90-s hiking at constantly varying hiking intensity interspersed with 10 s to tack) was developed. Ten male high-level Laser sailors performed an incremental cycling test (ICT; ie, step protocol at 80 W + 40 W/3 min) and an upwind sailing test (UST).