Modeling and Observer-Based Control of a Planar Two-Cable Crane Manipulator

Two-cable crane manipulators move heavy payloads through large workspaces with computer-controlled winches mounted on trolleys. To make the payload track prescribed translational and rotational trajectories, a control method is presented based on a mechanical model. A nonlinear feedforward control that exploits the flatness property of the system model provides the control inputs for the undisturbed motion along reference trajectories. Trajectory deviations and sway motions are stabilised by a superimposed feedback controller. A nonlinear observer for the estimation of nonmeasurable states completes the control concept.