Crane automation by decoupling control of a double pendulum using two translational actuators

Abstract

Modeling a crane as a double pendulum enables control of the position as well as the tilt of the load. Using the trolley motion and an additional translational actuator at the load suspension unit as system inputs, a control structure is described, that achieves damping of sway and tilt oscillations and establishes a decoupling between position and tilt angle of the load. These control features are the foundation for using the crane as a large workspace covering robot with six degrees of freedom. State space methods are used to design the decoupling control. Experimental results on a 5 ton bridge crane with workspace dimensions of 30 m/spl times/9 m/spl times/7 m show the performance of the presented concept.