Ship-mounted cranes are widely used in offshore constructions, resource exploitation and marine salvages, to transfer payloads. Due to serious sea conditions, unexpected motions of the ships caused by the wave will probably pose serious efficiency and security issues. Thus, the wave compensation system has become necessary equipment for the shipmounted crane. But wave-induced motions of the ship, parametric uncertainties and nonlinearities remain challenges for control of wave compensation systems, which needs to be solved urgently. In this paper, the mathematical model of the wave compensation system is established firstly. Then, a sliding mode controller is presented and the stability is proved considering ship roll movement. To deal with the unknown parameters of the system, the radial basis function (RBF) neural network is utilized in conjunction with sliding mode controller to construct an adaptive control strategy. Finally, both simulation and experiment results are included to verify the effectiveness of the proposed control strategy. The proposed control approach has better adaptability and greater robustness without chattering phenomenon, which can provides useful reference for other underactuated system facing persistent disturbances and parametric uncertainties.
Qiang, Hai-Yan; Xie, Si; Xu, Zhi-Qiang; and Sun, You-Gang
"An Enhanced Sliding Mode Control Method for Wave Compensation System of Ship-Mounted Cranes with Roll Motions and Parametric Uncertainties,"
Journal of Marine Science and Technology: Vol. 28:
6, Article 6.
Available at: https://jmstt.ntou.edu.tw/journal/vol28/iss6/6