A New Sliding-Mode Like Nonlinear Controller for Overhead Cranes with Smooth Control Inputs

In this paper, a novel sliding-mode-like nonlinear controller is proposed for overhead cranes, which successfully addresses the problem of simultaneously regulating the trolley position and eliminating the payload swing. To be specific, we first transform the original crane model into a quasi-linear form without making any approximations. An elaborately designed manifold is introduced subsequently. Then a novel nonlinear controller is designed to keep the system state on the manifold. Finally, some further analysis is presented to show that as long as some initial conditions are satisfied, the state variables will converge to the desired equilibrium point quasi exponentially fast when they are on the manifold. Lyapunov techniques are utilized to guarantee the performance of the closed-loop system. Furthermore, both simulation results and hardware experiments are subsequently provided to demonstrate the feasibility and efficiency of the proposed controller.