Experimental study of adaptive course controllers with nonlinear modulators for surface ships in shallow water
Chen, C.; Lataire, E.; Delefortrie, G. (2023). Experimental study of adaptive course controllers with nonlinear modulators for surface ships in shallow water. Isa Transactions 134: 417-430. https://dx.doi.org/10.1016/j.isatra.2022.08.005
In: Isa Transactions. ELSEVIER SCIENCE INC: New York. ISSN 0019-0578; e-ISSN 1879-2022, more
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Keywords |
Harbours and waterways > Manoeuvring behaviour > Open water Physical modelling Marine/Coastal |
Author keywords |
Ship manoeuvring; Course control; Model tests; Shallow water; Rudder efficiency |
Abstract |
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. Subsequently, the control system’s stability is analysed. Both course keeping and changing performance of the proposed controller are investigated via towing tank tests using a ship model of a Liquefied Natural Gas carrier. Finally, the applicability of controllers in shallow water is discussed. During experiments the developed algorithms show satisfactory course tracking ability in shallow and deep water. The advantages of better adaptability and higher rudder efficiency are verified by comparative results. Moreover, the impact of water depth on the controller cannot be ignored. |
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