Adaptive Nonlinear Antiswing Control for Underactuated Dual Ship-Mounted Cranes with Sea Wave Disturbances

As a cooperative lifting system, dual ship-mounted crane (DSMC) system is mainly used to transport large vol-ume of cargo and building materials in the marine environment. However, DSMC system is a complex nonlinear system with strong-coupling characteristics. Moreover, due to the lack of control inputs, some state variables can only be controlled indi-rectly through the coupling between states, which makes the controller design and corresponding analysis particularly difficult. Additionally, unlike cranes fixed on land, DSMC system is subject to disturbances such as ship motion caused by waves and currents, which means that the impact of waves on this system must be considered during transportation. Therefore, this paper proposes an efficient adaptive controller for DSMC system, which achieves accurate positioning of the boom and suppresses payload swing angle. The proposed control method is robust to unknown disturbances, and the stability is proved through the Lyapunov technique and LaSalle's invariance theorem. Finally, two groups of simulation results show the effectiveness of the control method.