Robust observer-based anti-swing control of 2D-crane systems with load hoisting-lowering

A new model-free robust control scheme for payload swing angle attenuation of two-dimensional crane systems with varying rope length is introduced in this work. The proposed controller consists of a proportional derivative controller, a disturbance observer, and a compensation term that includes a coupling function. A proper design of the coupling function allows attenuating the magnitude of the swing angle, while the disturbance observer permits reducing the effect of internal and external disturbances. Then, a rigorous stability analysis demonstrates that the proposed controller allows the system to follow a desired translational motion and hoisting/lowering the load with small payload oscillations despite the adverse effects caused by internal and external disturbances. In the proposed scheme, a stage devoted to the design of the reference signal is also encompassed. The new methodology is compared to a robust controller and an adaptive scheme. Exhaustive numerical simulations demonstrate that the new controller’s performance outperforms the other control techniques, despite the presence of endogenous and exogenous disturbances.