Adaptive SMC-based Trajectory Tracking Control of Underactuated Overhead Cranes

Overhead cranes, which are typically underactuated, are studied systematically nowadays. While, the model widely used in research is ideal. Thus, the corresponding controllers may react badly under external disturbances, unmodeled dynamics and input constraints. To tackle this issue, this paper develops an adaptive version of anti-sway trajectory tracking controller for overhead cranes. First, as to constrained input, we perform a mapping action from the system input to the hyperbolic tangent function. Then adaptation mechanisms are proposed to adjust the modified inputs and the system uncertainty. Such a controller achieves precise positioning and swing suppression despite input saturation, system uncertainty and external disturbances. The crane system proves to be dissipative with the proposed controller. The experiments accomplished on a laboratory-size bridge crane reveal that the proposed controller asymptotically stabilizes all system states.