A new overhead crane emergency braking method with theoretical analysis and experimental verification

Safety requirements are becoming increasingly important for various industrial production processes. Even though many facilities have been designed and used to ensure safety, the occurrence of some unexpected situations is still unavoidable. Therefore, suitable strategies should be designed in industry to deal with emergency situations. In this paper, we propose an emergency braking method for the commonly used overhead crane system to avoid accidents, such as collisions, when an unexpected situation occurs. Different from the typical industrial braking methods that stop the trolley immediately, the proposed method is designed considering payload swing suppression during the braking process, making the braking process safer. Additionally, the important payload safety limit is theoretically ensured. In particular, the detailed controller is designed by using the passivity property and the barrier Lyapunov function technique. Then, the convergence of the closed-loop system is proved using Lyapunov stability theory together with LaSalle's invariance principle. Furthermore, various experiments are implemented on a self-built overhead crane test bed that validate the effectiveness of this method.