Cooperative Sliding Mode Control Applied To A Fleet Of DP Vessels

This work presents an application of a Distributed Cooperative Control scheme for DP (Dynamic Positioning) marine vessels using Sliding Mode Control (SMC). The group task is to keep formation relative position within a tight tolerance. Global positioning is performed by means of a leader vessel that can be either real or virtual. Communication between ships is limited in order to keep a low data flow. The technique is applied to a group of 3-degree-of-freedom ships controlled by standard DP PID algorithms, subjected to winds, currents and waves forces. Results are then evaluated by simulation of a leader vessel and three other vessels performing relative positioning tasks, with and without the operation of the cooperation algorithm.