System Inversion Based Control of an Overhead Crane

Abstract In this paper we describe a new methodology for the control of the transient sway and of residual oscillation of the payload carried by an overhead crane. The approach consists of dampening the system by a state-feedback closed-loop and applying a noncausal system inversion in order to assure a predetermined polynomial motion law for the payload. Polynomial functions are adopted in order to guarantee that the input function has a continuous derivative of an arbitrary order. Moreover, the motion time can be minimized, taking into account constraints on the actuators, by means of a simple bisection algorithm. Simulation results, based on a nonlinear crane model, show how the method is effective also when the payload is hoisted or lowered during the motion, and how it is inherently robust to parameter uncertainties.