Type of Document Master's Thesis Author Henry, Ryan J. URN etd-070899-145159 Title Cargo Pendulation Reduction on Ship-Mounted Cranes Degree Master of Science Department Engineering Mechanics Advisory Committee
Advisor Name Title Nayfeh, Ali H. Committee Chair Hendricks, Scott L. Committee Member Mook, Dean T. Committee Member Keywords
- crane control
- ship-mounted crane
- time-delayed feedback
Date of Defense 1999-06-24 Availability unrestricted AbstractIt is sometimes necessary to transfer cargo from a large ship to a smaller ship at sea.
Specially designed craneships are used for this task, however the wave-induced motions of
the ship can cause large pendulations of cargo being hoisted by a ship-mounted crane. This
makes cargo transfer in rough seas extremely dangerous and therefore transfer operations
normally cease when sea state 3 is reached. If the cargo pendulations could be reduced in
higher sea states, transfer operations would be possible.
By controlling the boom luff angle, one can reduce the cargo pendulations in the plane of
the boom significantly. A two-dimensional pendulum with a rigid massless cable and massive
point load is used to model the system. A control law using time-delayed position feedback
is developed and the system is simulated on a computer using the full nonlinear equations of
motion. A three-degree-of-freedom ship-motion simulation platform, capable of simulating
heave, pitch, and roll motions, was built. The computer simulation results were
experimentally verified by mounting a 1/24th scale model of a T-ACS crane on the ship-motion
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