Recursive terminal sliding mode control for the 3D overhead crane systems with motion planning

In practical scenarios, the unexpected payload swinging of a 3D overhead crane can significantly diminish transportation efficiency and safety. To enhance transportation efficiency and address payload oscillation challenges inherent in 3D overhead crane systems, a novel recursive terminal sliding mode control strategy integrated with motion planning is presented in this work. Specifically, to reconcile the dual objectives of optimizing operational efficiency while mitigating payload swing, a novel smooth S-shaped reference trajectory is introduced, and a recursive terminal sliding mode controller is devised to trace this trajectory, incorporating the construction of a recursive sliding mode surface that combines swing angle and displacement deviation. Finally, the proposed method is validated through a series of numerical simulations and experimental trials. The outcomes highlight the robustness of the proposed controller, facilitating swift tracking of reference trajectory even in the presence of nonzero initial conditions or external disturbances. Notably, by significantly reducing payload swing angles, the proposed approach enhances transportation safety.