Finite-Time Neural Network-Based Hierarchical Sliding Mode Antiswing Control for Underactuated Dual Ship-Mounted...

As typical mechanical transportation equipment, cooperative dual ship-mounted cranes are widely used to transport large goods or containers in the marine environment. However, the control problem of the dual ship-mounted crane system is much more complex due to its underactuated characteristic and persistent unmatched disturbances. To solve these problems, we propose a novel neural network (NN)-based hierarchical sliding mode adaptive (HSMA) control method in this article. More specifically, an appropriate hierarchical sliding mode surface is first designed to connect the actuated and underactuated system state variables effectively. At the same time, the NNs are constructed to compensate for the unmatched interference of ship motions induced by sea waves simultaneously. Not only can the booms and the rope lengths reach their desired positions in finite time, but also the synchronous swing angles of the payload can be effectively eliminated. The asymptotic convergence of the closed-loop system's equilibrium points is achieved through rigorous mathematical proofs. Furthermore, the stability of each sliding mode surface is also analyzed utilizing the Lyapunov technique and Barbalat's lemma. Finally, numerous groups of compared numerical simulation results are investigated to further show the effectiveness and strong robustness of the proposed NN-based HSMA controller.