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Abstract. In general, hydraulic systems that are used for ship fin stabilizers and rudders, are modelled as first or second order of linear equations to obtain only system's delay and overshoot for controlling purposes. This approach assumes the hydraulic system is well designed and contains no faults. It's an easy and quick way to focus on control subject. However, limits and capacities of hydraulic components cannot be examined carefully with this approach. Due to this deficiency, expensive over-engineered or inadequate hydraulic systems can be designed. For this reason, an interdisciplinary study was done in Istanbul Technical University. The purpose of the study is to parametrically model hydraulic system of a ship motion reduction active fin stabilizer system with fins, ship roll dynamics and controllers in detail, so every property of the system can be observed in a simulation environment via non-linear equations. With the help of parametric modelling, every component can be changed and resized easily, including the ship, fins, hydraulic components and controllers. Results obtained from simulation are verified with full scale sea trials using a ship named Volcano71.

Measurement, data transfer, modelling, controller systems are main subjects of interdisciplinary area during prototyping of marine automatic control systems. Experimental parameter identification under changing environmental conditions is an essential step for modelling and control system design are in question for various marine applications. The selection of variables to be measured, type of measurement sensors, type of control algorithms and controller systems, communication, signal conditioning are all important topics for parameter identification and real-time control applications in maritime engineering. The objective of this paper is to present brief review these important topics based on our case studies, such as ship roll motion reduction control, optimal trim control of a high speed craft, and dynamic position control of underwater vehicles. These projects involved extensive dynamic modelling, simulation, control algorithm design, real-time implementation and full-scale sea trials. In this paper, presented the methods, and the required characteristics of the marine control systems are proved with the results obtained by the simulation and test studies. Also, insight into the selection of hardware and software components for mechatronic applications in marine engineering is provided.