NGMVC scheme on marine surface vessels dynamic positioning and manoeuvring

A new generation of dynamic ship positioning systems is discussed in this paper, which takes into account the nonlinearities in the system rather than using a linear approximation. This should lead to significant advantages in performance and in the energy utilization since the control design takes into account the nonlinear dynamics of the ship explicitly. The paper starts with the
introduction of the ship models, disturbances and control design. The objective is to control the axial velocities of a fully actuated vessel and to keep it stationary at a point or guide it along a specified 2-axis geometric trajectory approach. Environmental and system disturbances are considered along the process to evaluate the performance of the particular scheme and compare
them to classical PID control design with notch filters. Simulation study will be presented to demonstrate the performance of the design and a comparison with the traditional system of Proportional- Integral- Derivate (PID) controller [1] will be carried out. The NGMV controller provides much improved performance across the operating range. Moreover as 2-degrees of freedom controller [2] it handles the variances about the response, including disturbance rejection, separately than the tracking problem. For simulation purposes the CyberShip II model is
considered [3].