Double Closed-loop Anti-swing Control for Overhead Containers Based on Multiple Models Reference Switching

Abstract

Due to the unmodeled dynamics of the plant and to disturbances like wind,the residual swing always exists during fast loading / unloading of the containers from the container ship.In order to enhance the trolley's capability of eliminating the swing of containers,the algorithm of multiple models reference switching double closed-loop anti-swing control is presented,which regards event-driven as the switching rule.By means of Lagrange dynamic equation,the mathematic model is established for anti-swing systems of overhead containers according to the mutual relationship between the swing angle of the load and the acceleration of the trolley.The image to get the swing angle signal is detected by the machine vision sensor composed of the camera and reflectors,which is introduced to compose double closed-loop control system.The computer simulations and experiments with the laboratory-size model of the overhead container system are carried out simultaneously.The results show that adopting the proposed method,the range of the load swing angle is ±0.05 radian during the whole working process of the trolley,at the same time,the range of the load swing angle is ±0.01 radian when the trolley stops at the target position.The practical use requirement is satisfied.