FDI Toolbox
  1.5 MB

A Matlab Tool for Frequency-Domain Identification of Radiation-Force Models of Ships and Offshore Structures:

This is an independent Matlab toolbox for parametric identification of fluid-memory models associated with  the radiation forces ships and offshore  structures. Radiation forces are a key component of force-to-motion models used in simulators, motion control designs, and also for initial performance evaluation of wave-energy converters. 
The software described provides tools for preparing non-paramatric data and  for identification with  automatic model-order detection. The identification problem  is considered in the frequency domain.

The toolbox includes two demos:

1. Identification of fluid-memory models using infinite-frequency added mass. This is intended for 3D hydrodynamic codes like WAMIT where infinite-frequency added mass is computed by solving a boundary value problem.
2. Estimation of the infinite-frequency added mass together with the fluid-memory model. This is particular useful for 2D hydrodynamic codes like ShipX (VERES) that do not provide the infinite-frequency added mass.

Reference/documentation:

Perez, T. and T. I. Fossen (2009). A Matlab Tool for Parametric Identification of Radiation-Force Models of Ships and Offshore Structures. Modelling, Identification and Control, MIC-30(1):1-15. doi:10.4173/mic.2009.1.1