This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Masoud, Z. N. Articles by Nayfeh, N. A. Search for Related Content Social Bookmarking                   What's this?

Pendulation Reduction on Small Ship-Mounted Telescopic Cranes

Mohammed F. Daqaq

Nader A. Nayfeh

Department of Engineering Science and Mechanics, MC 0219, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA

Small ship-mounted telescopic cranes are used to load and unload cargo of limited size and weight. The wave-induced motions of the crane ship can cause large pendulations of the hoisted payload bringing the transfer operations to a complete halt. The small size of such a crane, combined with its limited maneu-verability, compared to the relatively larger motion of the host ship, poses a serious control challenge. In this work, a nonlinear control system is introduced which reduces pendulations on these cranes to the point where the transfer operations do not pose a dangerous working environment. Delayed position-feedback technique is used to reduce the payload pendulations. The presented control system uses the slewing, luffing, and telescopic degrees of freedom of the crane to drive the horizontal position of the boom tip. The saturation problem arising from the limited speed and motion of the crane actuators is another issue addressed by this control technique. To demonstrate the performance of the developed control system, numerical simulations are performed on a nonlinear three-dimensional mathematical model of the telescopic crane mounted on the USNS WATERS. The crane has four degrees of freedom: hoisting, slewing, luffing, and extension of the telescopic boom. In addition to its limited maneuverability, nonlinear hydraulic actuators are used for the luffing and extensional degrees of freedom.

Key Words: Telescopic cranes • sway control • delayed position-feedback control

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				Z. N. Masoud, A. H. Nayfeh, and N. A. Nayfeh Sway Reduction on Quay-side Container Cranes Using Delayed Feedback Controller: Simulations and Experiments Journal of Vibration and Control, August 1, 2005; 11(8): 1103 - 1122. [Abstract] [PDF]