Barrier function-based adaptive antisway control for underactuated overhead cranes

Nonlinear controls that account for constraints on the state variable of overhead cranes can hardly strengthen the effective coupling between trolley movement and load oscillation, thus possessing little capacity in oscillation suppression. Nevertheless, such control designs trend to be more complex under parametric uncertainties. To solve these problems, this paper employs novel barrier functions in the coupling control design, so that the obtained feedback can preserve all states, including the composite variable, bounded within asymmetric limits while simultaneously enhancing antisway effectiveness. Owing to the simple structure of the Lyapunov derivative, the adaptation facilitates the proposed controller with robustness to parametric uncertainties. LaSalle's invariance principle ensures the asymptotic stability, and experiments verify the validity of the suggested controller.