Control of a Tower Crane (Control for Boom Angle)

This paper discusses control of a crane mounted on a tower-like flexible structure. Although a fast transfer of the load suspended from the edge of the boom of the crane causes not only the sway of the load itself but also the vibration of the flexible structure, the objective of this study is to control both the sway of the load and the vibration of the flexible structure by the up-and-down positioning control torque to the boom. At first a mathematical model for the experimental model of the tower crane and a reduced order model for a controller design are introduced. Next, we design an H∞ compensator for the reduced order model so that the compensator simultaneously controls the position of the boom, the sway of the load and the vibration of the flexible structure, and suppresses the spillover phenomenon due to the model reduction. By simulations and experiments it is verified that the designed compensator has superior vibration control performances to those the conventional angular velocity control for the boom has.