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

Modeling a crane as a double pendulum enables to control the position of the load 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 to use 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 at a 5 tons bridge crane with workspace dimensions of 30 m x 9 m x 7 m show the performance of the presented concept.