Control design for the rotation of crane loads for boom cranes

This paper handles the control of flexible link robot systems. Since in the considered case a manipulator for grabbing containers is suspended on two ropes, torsional oscillation occurs changing the position of the manipulator. A control strategy, which consists of feedforward and disturbance observer based feedback control implemented on boom cranes to assure an accurate tracking of the manipulator along a reference path is shown. The system parameters like rope length, moment of inertia of the load and its mass are changed frequently during the crane operation. Therefore the controller is fully adaptive due to the varying system parameters. Measurement results show the efficiency of the presented control strategy implemented on a harbor mobile crane LIEBHERR LHM 400.