해양크레인시스템의 수정된 2차 슬라이딩모드제어

Abstract

In this paper, a super-twisting (i.e., modified 2nd-order) sliding mode control (STSMC) is proposed for sway control of an offshore container crane system (i.e., a mobile harbor system equipped with a container crane on it). The mobile harbor is used for ship-to-ship transfer of containers, where the container ship is anchored in an open sea. To load/unload the containers in an open sea, it is necessary to suppress the position error of the load caused by the wave-induced movements of the mobile harbor. In this paper, a super-twisting sliding mode controller is developed for suppressing the position error of the payload. The sliding surface is designed in such a way that the longitudinal sway of the load is incorporated within the trolley dynamics. The chattering problem is also solved by utilizing a second order sliding surface. Lyapunov function-based stability analysis is performed to prove the uniform stability of the closed-loop system. Simulation results are provided to prove the effectiveness of the proposed control law.