Magnetorheological anti-swing system for offshore cranes subject to irregular wave excitation: Dynamic analysis and experiment

To resolve the challenge of payload oscillation during offshore crane operations and to boost the lifting process’s efficiency and safety, the incorporation of magnetorheological (MR) technology into the anti-swing system of shipboard cranes is proposed. A parallel MR damper anti-swing system is designed. The dynamic model of the MR damper anti-swing system is established using robotics theory. A co-simulation analysis for the MR damper anti-swing system is carried out in MATLAB and Adams under irregular waves based on the JONSWAP spectrum. The performance of the MR damper anti-swing system under a fixed current, along with the accuracy of its dynamic model, has been confirmed through experiments on a physical prototype. To improve system robustness, a fuzzy sliding mode controller is designed by integrating fuzzy control theory into a sliding mode controller, implementing a time-varying current control strategy. Comparative results show that, with the MR anti-swing system, the swing angles (include out-plane and in-plane angle) of the payload are reduced by more than 80%, respectively.