A PD sliding mode swing suppression control method for bridge cranes with an improved reaching law

To overcome the undesirable swing caused by inertia during the operation of bridge cranes, an improved reaching law-based Proportional-Derivative sliding mode control(IRL-PD-SMC) method is proposed. This method effectively suppresses the load swing angle while ensuring precise and rapid arrival of the trolley at the target position. Firstly, a generalized error signal is constructed by combining the coupling signals of trolley displacement and load swing angle, and a sliding mode controller is built based on conventional sliding mode control(CSMC) theory. Subsequently, a PD equivalent control component is designed to enhance system stability. Meanwhile, the traditional exponential reaching law is improved by introducing a nonlinear reaching law to reduce system chattering. Finally, the asymptotic stability of the equilibrium point of the closed-loop system is proven using the Lyapunov method and Schur’s lemma. Experimental results show that this controller exhibits excellent positioning and anti-swing performance.