Modeling and control of a three-dimensional overhead crane

In this paper, a new dynamic model of a three-dimensional overhead crane is derived based on a newly defined two-degree-of-freedom swing angle. The dynamic model describes the simultaneous traveling, traversing, and hoisting motions of the crane and the resulting load swing. For anti-swing control, this paper proposes a decoupled control scheme based on the dynamic model linearized around the stable equilibrium The decoupled scheme guarantees not only rapid damping of load saving but also accurate control of crane position and load hoisting for the practical case of simultaneous traveling, traversing, and slow hoisting motions, which is also proven by experiments.