Fuzzy-based adaptive control method for automatic mooring systems

Abstract

An automatic mooring system is not only safer and more economical than a traditional mooring system with ropes but also significantly reduces the mooring time. In this paper, we propose an automatic mooring system designed to securely berth vessels entering a port, along with an efficient control method aimed at constraining vessel movement within a specific range. To assess the operational range and control performance of the proposed system in a marine environment, a dynamic analysis program was employed to create a simulator. The simulator incorporated a parallel structured Stewart platform to replicate the 6-DOF motion of a marine vessel. The proposed automatic mooring system controller regulates the position using a time-delay controller (TDC). TDC has proven to be excellent for effectively predicting system uncertainty and handling changes in system dynamics. However, given the unpredictable nature of extreme disturbances in marine environments, it is essential to adaptively modify the control parameters to ensure optimal performance. The method presented in this paper employs a fuzzy logic controller (FLC) to dynamically adjust the control parameters of the TDC, enabling effective adaptation to rapidly changing marine conditions, including waves and wind.