Sliding-mode control for an underactuated overhead crane system

This paper presents an anti-swing control for underactuated overhead crane systems. The minimizing load-swing angle and maximizing the speed of load transfer along the pre-specified path are contradict to each other, which indicates the stability of swing dynamics of load and accurate trolley position control are hard to consider and implement simultaneously by using fewer actuators. In this study, an anti-swing control scheme is designed based on the sliding-mode control (SMC) to satisfy the strict specification on the swing angle and accurate trolley position control in spite of unmodeled-parameter errors. Furthermore, a complete analysis of stability of load-swing dynamics induced by SMC is provided. Simulation shows that the proposed control scheme ensures the asymptotically stability of sliding surface, precise trolley positioning, load hoisting and good performance of the load-swing dynamics during the load transfer.