Picture of athlete cycling

Open Access research with a real impact on health...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by Strathclyde researchers, including by researchers from the Physical Activity for Health Group based within the School of Psychological Sciences & Health. Research here seeks to better understand how and why physical activity improves health, gain a better understanding of the amount, intensity, and type of physical activity needed for health benefits, and evaluate the effect of interventions to promote physical activity.

Explore open research content by Physical Activity for Health...

Ship forward speed loss minimization using nonlinear course keeping and roll motion controllers

Liu, Zhiquan and Jin, Hongzhang and Grimble, Michael J. and Katebi, Reza (2016) Ship forward speed loss minimization using nonlinear course keeping and roll motion controllers. Ocean Engineering, 113. pp. 201-207. ISSN 0029-8018

Full text not available in this repository. Request a copy from the Strathclyde author


Ship forward speed can be significantly reduced by the added resistance generated by the effect of wave motion. Controlling the ship motions using the actuators available can reduce this speed loss. The use of ship rudder for both steering and roll reduction is considered here with the aim of reducing speed loss. The added resistance due to the wave effects is calculated by the extended radiated energy method and the added resistance in calm water, caused by steering, is also included. In order to judge the speed loss that occurs, a performance index is proposed to quantify the percentage of speed loss. A control system based on the sway-yaw and the roll dynamics is proposed to reduce the ship speed loss. The controller comprises two sliding mode controllers developed using ship dynamic models. Finally, an example of the control of a navy vessel with two rudders is presented to demonstrate the effectiveness of the proposed solution.