Gain-Scheduled Control of a Tower Crane Considering Varying Load-Rope Length.

This paper discusses control of a crane mounted on a tower-like structure in case of varying load-rope length. A fast transfer of the load causes the sway of the load rope and the vibration of the flexible structure. Our object is to control both the sway and the vibration by control of torque to the boom. If the length of the load rope varies, it is difficult to control by the fixed compensator, because not only the natural frequency of the load rope but also gain of the plant to the control input vary. We design the gain-scheduled H∞ controller based on the LMI for the length of the load rope and verify the efficiency of the controller by simulaitons and experiments.