Patent ID: 7171342
Filing Date: 2007-01-30
Classification: B63G,G01R

Abstract:
1. Method for determining magnetization of a field radiated by a ferromagnetic sheet using magnetic field sensors distributed along the ferromagnetic sheet at known positions relative to the ferromagnetic sheet, the method comprising: Creating a surface mesh of the ferromagnetic sheet by dividing the ferromagnetic sheet into elementary surfaces, Creating a first magnetic field model that is associated with measurements of the magnetic field sensors and which is a function of the surface mesh of the ferromagnetic sheet, a thickness of the ferromagnetic sheet, the measurements of the magnetic field sensors, the coordinates of the known positions, and an inductive field B Creating a second model of physical behavior of the ferromagnetic sheet material from the surface mesh, the thickness of the ferromagnetic sheet, the inductive field, and reversible permeability of the ferromagnetic sheet material, Calculating permanent and induced magnetizations of each of the elementary surfaces from said first and second models and the measurements made by said magnetic field sensors, Calculating a magnetic signature of the ferromagnetic sheet at a plurality of points from said permanent and induced magnetizations of each of the elementary surfaces, from the surface mesh of the ferromagnetic sheet, the thickness of the ferromagnetic sheet, the measurements by the magnetic field sensors, the coordinates of the known positions, and the inductive field B Outputting a calculated magnetic signature of the ferromagnetic sheet to allow compensation of the magnetic signature.