Sliding Mode Observer-Based Super-Twisting Controller for Under-Actuated Bridge Cranes Subject to Double-Pendulum Effect

Operating a bridge crane under large amplitude cargo sways is problematic and dangerous from both an efficiency and a safety standpoint. The situation deteriorates further when the payload develops a double-pendulum (DP) effect. The dynamic behavior of bridge crane systems susceptible to the DP effect is studied in the context of persistent multiplicative disturbances in this paper. A modified sliding mode observer (SMO) with uncertainty compensation is proposed to predict the unavailable states of the system. Simple implementation, noise resiliency, bounded-time convergence, and the absence of complex or inaccessible coordinate transformation are the notable features of the proposed SMO. A composite SMO-based modified super-twisting control technique is designed to achieve the goal of rapid and precise trolley placement and speedy cargo swing suppression. It has been proved that the suggested hybrid control method maintains the system’s asymptotic stability by using a strict quadratic Lyapunov function. The proposed control system’s efficacy has been demonstrated via rigorous simulation experiments.