Marine course-changing manoeuvre: a comparative study of control algorithms

This paper describes several control structures for steering manoeuvres in a non-linear model of the R.O.V. Zeefakkel ship. The nonlinearity of the model appears in considerable variations both the parameters of its rudder course-changing commands and the saturation of its rudder angle and speed. This nonlinear behaviour causes a greater difficulty in the adjustment of the parameters of a single controller for the full range of possible changes in course. The control algorithms shown here are: the classical controllers tuned using genetic algorithms, quantitative feedback theory (QFT) and internal model control (IMC). In this comparative study it is observed that the course-change manoeuvre is satisfactorily achieved without over damping with the three algorithms applied. Moreover, the responses obtained with the QFT and classical controllers are faster than the IMC controller.