### “Joint Identification of Infinite-Frequency Added Mass and Fluid-Memory Models of Marine Structures”

**Authors:**Tristan Perez and Thor I. Fossen,

**Affiliation:**University of Newcastle (Australia), NTNU, Department of Engineering Cybernetics and NTNU, Centre for Ships and Ocean Structures

**Reference:**2008, Vol 29, No 3, pp. 93-102.

**Keywords:**Identification, Frequency-domain, Marine Structure Models

**Abstract:**This paper addresses the problem of joint identification of infinite-frequency added mass and fluid memory models of marine structures from finite frequency data. This problem is relevant for cases where the code used to compute the hydrodynamic coefficients of the marine structure does not give the infinite-frequency added mass. This case is typical of codes based on 2D-potential theory since most 3D-potential-theory codes solve the boundary value associated with the infinite frequency. The method proposed in this paper presents a simpler alternative approach to other methods previously presented in the literature. The advantage of the proposed method is that the same identification procedure can be used to identify the fluid-memory models with or without having access to the infinite-frequency added mass coefficient. Therefore, it provides an extension that puts the two identification problems into the same framework. The method also exploits the constraints related to relative degree and low-frequency asymptotic values of the hydrodynamic coefficients derived from the physics of the problem, which are used as prior information to refine the obtained models.

PDF (539 Kb) DOI: 10.4173/mic.2008.3.2

**DOI forward links to this article:**

[1] Tristan Perez and Thor I. Fossen (2011), doi:10.1016/j.oceaneng.2010.11.004 |

[2] Tristan Perez and Thor Inge Fossen (2009), doi:10.4173/mic.2009.1.1 |

[3] C E Hann, M Snowdon, A Rao, O Winn, N Wongvanich and X Chen (2012), doi:10.1177/0954410011420771 |

[4] Wenshou Zhang, Jian Cheng and Yaoquan Duan (2017), doi:10.4236/jamp.2017.59136 |

[5] A Zasso, T Argentini, I Bayati, M Belloli and D Rocchi (2017), doi:10.1088/1757-899X/276/1/012008 |

[6] Changhai Liu, Qingjun Yang and Gang Bao (2018), doi:10.1016/j.oceaneng.2017.12.063 |

[7] J. Seixas de Medeiros and S. Brizzolara (2018), doi:10.1155/2018/1710253 |

[8] Changhai Liu, Qingjun Yang and Gang Bao (2018), doi:10.1080/17445302.2018.1427317 |

[9] Simone Ambrosini, Ilmas Bayati, Alan Facchinetti and Marco Belloli (2020), doi:10.1115/1.4046155 |

[10] Panagiotis Dafnakis, Amneet Pal Singh Bhalla, Sergej Antonello Sirigu, Mauro Bonfanti, Giovanni Bracco and Giuliana Mattiazzo (2020), doi:10.1063/5.0022401 |

[11] Mauro Bonfanti, Andrew Hillis, Sergej Antonello Sirigu, Panagiotis Dafnakis, Giovanni Bracco, Giuliana Mattiazzo and Andrew Plummer (2020), doi:10.3390/jmse8100825 |

**References:**

[1] Agüero, J. C. (2005). System Identification Methodologies Incorporating Constraints, Ph.D. thesis, Department of Elec. Eng. and Comp. Sc., The Univeristy of Newcastle, Australia.

[2] Cummins, W. (1962). The impulse response function and ship motion, Technical Report 1661, David Taylor Model Basin-DTNSRDC.

[3] Damaren, C. (2000). Time-domain floating body dynamics by rational approximations of the radiation impedance and diffraction mapping, Ocean Engineering. 27:687-705 doi:10.1016/S0029-8018(99)00015-3

[4] Faltinsen, O. (1990). Sea Loads on Ships and Offshore Structures, Cambridge University Press.

[5] Gourieroux, C. Monfort, A. (1995). Statistics and Econometric Models: General Concepts, Estimation, Prediction and Algorithms, volume 1 of Themes in Modern Econometrics, Cambridge Univ. Press.

[6] Hjulstad, A., Kristansen, E., Egeland, O. (2004). Statespace representation of frequency-dependant hydrodynamic coefficients, In Proc. IFAC Confernce on Control Applications in Marine Systems.

[7] Holappa, K. Falzarano, J. (1999). Application of extended state space to nonlinear ship rolling, Ocean Engineering. 26:227-240 doi:10.1016/S0029-8018(97)10027-0

[8] Jefferys, E., Broome, D., Patel, M. (1984). A transfer function method of modelling systems with frequency dependent coefficients, Journal of Guidance Control and Dynamics. .4:490-494 doi:10.2514/3.19883

[9] Jefferys, E. Goheen, K. (1992). Time domain models from frequency domain descriptions: Application to marine structures, International Journal of Offshore and Polar Engineering. 2:191-197.

[10] Jordan, M. Beltran-Aguedo, R. (2004). Optimal identification of potential-radiation hydrodynamics of moored floating stuctures, Ocean Engineering. 31:1859-1914 doi:10.1016/j.oceaneng.2004.01.007

[11] Kaasen, K. Mo, K. (2004). Efficient time-domain model for frequency-dependent added mass and damping, In 23rd Conference on Offshore Mechanics and Artic Engineering.OMAE, Vancouver, Canada.

[12] Kristansen, E. Egeland, O. (2003). Frequency dependent added mass in models for controller design for wave motion ship damping, In 6th IFAC Conference on Manoeuvring and Control of Marine Craft MCMC'03, Girona, Spain.

[13] Kristiansen, E., Hjulstad, A., Egeland, O. (2005). Statespace representation of radiation forces in timedomain vessel models, Ocean Engineering. 32:2195-2216 doi:10.1016/j.oceaneng.2005.02.009

[14] Levy, E. (1959). Complex curve fitting, IEEE Trans. Autom. Control. AC-4:37-43.

[15] McCabe, A., Bradshaw, A., Widden, M. (2005). A time-domain model of a floating body using transforms, In Proc. of 6th European Wave and Tidal energy Conference. University of Strathclyde, Glasgow, U.K.

[16] Newman, J. (1964). Marine Hydrodynamics, MIT Press. Ogilvie, T. Recent progress towards the understanding and prediction of ship motions. In 6th Symposium on Naval Hydrodynamics.

[17] Perez, T. Fossen, T. I. (2008). Time-domain vs frequency-domain identification of parametric radiation force models for marine structures at zero speed, Modeling Identification and Control, published by The Norwegian Society of Automatic Control. 2.1:1-19 doi:10.4173/mic.2008.1.1

[18] Perez, T. Lande, Ø. (2006). A frequency-domain approach to modelling and identification of the force to motion vessel response, In Proc. of 7th IFAC Conference on Manoeuvring and Control of marine Craft, Lisbon, Portugal.

[19] Sanathanan, C. Koerner, J. (1963). Transfer function synthesis as a ratio of two complex polynomials, IEEE Trans. of Autom. Control.

[20] Söding, H. (1982). Leckstabilität im seegang, Technical report, Report 429 of the Institue für Schiffbau, Hamburg.

[21] Sutulo, S. Guedes-Soares, C. (2005). An implementation of the method of auxiliary state variables for solving seakeeping problems, Int. Ship Buildg. Progress. 5.4:357-384.

[22] Taghipour, R., Perez, T., Moan, T. (2008). Hybrid frequency-time domain models for dynamic response analysis of marine structrues, Ocean Engineering doi:10.1016/j.oceaneng.2007.11.002

[23] Verhaegen, M. Verdult, V. (2007). Filtering and System Identification, Cambridge.

[24] Xia, J., Wang, Z., Jensen, J. (1998). Nonlinear wave-loads and ship responses by a time-domain strip theory, Marine strcutures. 11:101-123.

[25] Yu, Z. Falnes, J. (1995). Spate-space modelling of a vertical cylinder in heave, Applied Ocean Research. 17:265-275 doi:10.1016/0141-1187(96)00002-8

**BibTeX:**

@article{MIC-2008-3-2,

title={{Joint Identification of Infinite-Frequency Added Mass and Fluid-Memory Models of Marine Structures}},

author={Perez, Tristan and Fossen, Thor I.},

journal={Modeling, Identification and Control},

volume={29},

number={3},

pages={93--102},

year={2008},

doi={10.4173/mic.2008.3.2},

publisher={Norwegian Society of Automatic Control}

};