A payload swing suppression guaranteed emergency braking method for overhead crane systems

In practice, since the working environments are usually complex, the emergency braking problem has been an important issue for overhead crane applications. To ensure safety and avoid accidents such as collision, when braking is required for a crane system, not only the trolley displacement, but also the payload swing, should be considered. However, the most commonly used industrial braking method, which stops the trolley immediately, may cause unavoidable severe payload swing, due to the lack of consideration for the system state couplings. Considering this fact, to obtain better braking control performance, in this paper, a novel emergency braking method is proposed, which successfully suppresses the payload swing during the braking process. In particular, the braking objective is divided into two parts, with an effective controller designed separately. Then a complete braking controller is obtained by combining the separate controllers properly, which can achieve fast trolley braking and efficient payload swing suppression. Finally, both simulation and experimental tests are included in this paper to illustrate the satisfactory control performance of the proposed method.