Enhanced Couple Hierarchical Sliding Mode Control for Bridge Cranes with Matching Disturbances

Bridge crane plays an irreplaceable role in the industrial field, so the stabilization control of bridge crane is of great significance. However, improving the transient performance of the control system is still one of the major challenges in the research of the control method of bridge crane system. To solve this problem, a hierarchical sliding mode tracking control strategy with enhanced coupling is proposed in this paper. Firstly, the coupling signal is carefully designed, and then the coupling signal is introduced to transform the bridge system model accordingly. Finally, the tracking controller is designed to make the system state approach to the desired equilibrium point in finite time. Under the action of the controller designed in this paper, the trolley can fully restrain the load swing when it reaches the desired position. When sudden unmatched interference occurs, the system state can be quickly restored to the equilibrium point. The stability analysis is also given. Simulation results show that this strategy can improve the transient performance of the controller.