It is often desirable to keep the load of an offshore crane in a fixed point in space despite the movement of its base. To solve the problem of stabilizing the load’s position, the authors have proposed application of the hoisting winch drum’s drive and an auxiliary system. The auxiliary system enables independent moving of a selected point of the hoisting rope in two perpendicular planes. In this paper, two methods for determining the drive functions of the auxiliary system and the hoisting winch’s drum ensuring stabilization of an offshore crane’s load are presented. Both methods are based on a simplified model of a crane and allow compensation for a pseudo-harmonic base motion. In order to take into account the deviations of base motion from the assumed and avoid over simplifications, the second, more sophisticated model is developed. This model is proposed to be applied in closed-loop control systems with a PID controller. Results of sample numerical simulations are included that proved useful information about the developed methods and models for stabilization of an offshore crane’s load.

References

References
1.
Birkeland
,
O.
, 1998, “
Knuckle Boom Combination Crane
,”
3rd International Offshore Cranes Conference
,
Stavanger, Norway
.
2.
Balachandran
,
B.
,
Li
,
Y. Y.
, and
Fang
,
CC.
, 1999, “
A Mechanical Filter Concept for Control of Non-Linear Crane-Load Oscillations
,”
J. Sound Vib.
,
228
, pp.
651
682
.
3.
Li
,
Y. Y.
, and
Balachandran
,
B.
, 2001, “
Analytical Study of a System With a Mechanical Filter
,”
J. Sound Vib.
,
247
, pp.
633
653
.
4.
Cosstick
,
H.
, 1996, “
The Sway Today
,” Container Management, pp.
42
43
.
5.
Folso
,
L.
, and
Rizzuto
,
E.
, 2003, “
Equivalent Waves for Sea Loads on Ship Structures
,”
22nd Int. Conf. Offshore Mech. Arct. Eng.
, Cancun, Mexico.
6.
Das
,
S. N.
, and
Das
,
S. K.
, 2005, “
Mathematical Model for Coupled Roll and Yaw Motions of a Floating Body in Regular Waves Under Resonant and Non-Resonant Conditions
,”
Appl. Math. Model.
,
29
, pp.
19
34
.
7.
Osiński
,
M.
, and
Wojciech
,
S.
, 1998, “
Application of Nonlinear Opitmisation Methods to Input Shaping of the Hoist Drive of an Off-Shore Crane
,”
Nonlinear Dyn.
,
17
, pp.
369
386
.
8.
Osiński
,
M.
,
Maczyński
,
A.
, and
Wojciech
,
S.
, 2004, “
The Influence of Ship’s Motion in Regular Wave on Dynamics of an Offshore Crane
,”
Arch. Mech. Eng.
,
51
(
2
), pp.
131
163
.
9.
Ellermann
,
K.
,
Kreuzer
,
E.
, and
Markiewicz
,
M.
, 2002, “
Nonlinear Dynamics of Floating Cranes
,”
Nonlinear Dyn.
,
27
(
2
), pp.
107
183
.
10.
Ellermann
,
K.
,
Kreuzer
,
E.
, and
Markiewicz
,
M.
, 2003, “
Nonlinear Primary Resonances of a Floating Crane
,”
Meccanica
,
38
, pp.
5
18
.
11.
Masoud
,
Y. N.
, 2000, “
A Control System for the Reduction of Cargo Pendulation of Ship-Mounted Cranes
,” Ph.D. thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA.
12.
Fossen
,
T. I.
, 1994,
Guidance and Control of Ocean Vehicles
,
John Wiley & Sons
,
Chichester, UK.
13.
Driscoll
,
F. R.
, and
Lueck
,
R.
Nahon
,
G. M.
,
, 2000, “
Development and Validation of a Lumped-Mass Dynamics Model of a Deep-Sea ROV System
,”
Appl. Ocean Res.
,
22
, pp.
169
182
.
14.
Pedrazzi
,
C.
, and
Barbieri
,
G.
, 1998, “
LARSC: Launch and Recovery Smart Crane for Naval ROV Handling
,”
13th European ADAMS Users’ Conference
, Paris.
15.
Witz
,
J. A.
, 1995, “
Parametric Excitation of Crane Loads in Moderate Sea States
,”
Ocean Eng.
,
22
(
4
), pp.
411
420
.
16.
Wittbrodt
,
E.
,
Adamiec-Wójcik
,
I.
, and
Wojciech
,
S.
, 2006,
Dynamics of Flexible Multibody Systems
,
Springer
,
New York
.
17.
Adamiec-Wójcik
,
I.
,
Maczyński
,
A.
, and
Wojciech
S.
, 2008, “
Application of Homogonous Transformations to Modelling Dynamics of Offshore Mechanics
,”
Wydawnictwo Komunikacji i Lacznosci (2008) (in Polish)
.
18.
Maczyński
,
A.
, and
Wojciech
S.
, 2003, “
Dynamics of a Mobile Crane and Optimization of the Slewing Motion of its Upper Structure
,”
Nonlinear Dyn.
32
, pp.
259
290
.
19.
Wit
,
R.
, 1986, “
Methods of Nonlinear Programming. Minimization of Smooth Functions
,” WNT (1986) (in Polish).
20.
Kruszewski
,
J.
and
Wittbrodt
,
E.
, 1992, “
Computer Methods in Vibrations of Mechanical Systems
,” Tom I. WNT. Warsaw (1992) (in Polish).
You do not currently have access to this content.