Methods, systems and devices for detecting and locating ferromagnetic objects
First Claim
1. A method for detecting and locating ferromagnetic objects, the method comprising:
- acquiring magnetic data comprising magnetic field gradients detected during a period of time;
representing the magnetic data as a function of the period of time;
converting the magnetic data to being represented as a function of frequency;
setting a first bin of values of the magnetic data represented as a function of frequency to zero; and
reverting the magnetic data represented as a function of frequency to be represented as a function of time to produce reverted data values.
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Accused Products
Abstract
Methods for detecting and locating ferromagnetic objects in a security screening system. One method includes a step of acquiring magnetic data that includes magnetic field gradients detected during a period of time. Another step includes representing the magnetic data as a function of the period of time. Another step includes converting the magnetic data to being represented as a function of frequency. Another method includes a step of sensing a magnetic field for a period of time. Another step includes detecting a gradient within the magnetic field during the period of time. Another step includes identifying a peak value of the gradient detected during the period of time. Another step includes identifying a portion of time within the period of time that represents when the peak value occurs. Another step includes configuring the portion of time over the period of time to represent a ratio.
15 Citations
20 Claims
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1. A method for detecting and locating ferromagnetic objects, the method comprising:
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acquiring magnetic data comprising magnetic field gradients detected during a period of time; representing the magnetic data as a function of the period of time; converting the magnetic data to being represented as a function of frequency; setting a first bin of values of the magnetic data represented as a function of frequency to zero; and reverting the magnetic data represented as a function of frequency to be represented as a function of time to produce reverted data values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A security screening system, the system comprising:
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a portal structure comprising a pair of opposing columns extending vertically and defining a passageway; an array of magnetic sensors arranged in each one of the opposing columns and configured to output magnetic data, each magnetic sensor comprising a vertical position relative to a ground level in its associated column and being aligned with a corresponding magnetic sensor at substantially the same vertical position in the opposing column; and a processor coupled to each magnetic sensor and configured to; convert magnetic data from each magnetic sensor to be represented as a function of frequency; set a first bin of values of the magnetic data represented as a function of frequency to zero; and produce reverted data values comprising the magnetic data represented as a function of frequency reverted to be represented as a function of time. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. A method for detecting and locating ferromagnetic objects, the method comprising:
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sensing a magnetic field for a period of time with a plurality of magnetic sensors arranged in an array in each of two opposing columns, each magnetic sensor among the plurality of magnetic sensors comprising a vertical position relative to a ground level in one among the two opposing columns and being aligned with a corresponding magnetic sensor at substantially the same vertical position in the other opposing column; detecting a gradient within the magnetic field during the period of time using at least some of the magnetic sensors among the plurality of magnetic sensors; identifying a peak signal power value of the gradient detected during the period of time, the peak signal power value being related to at least one magnetic sensor among the at least some of the magnetic sensors; interpreting the peak signal power value as indicating a presence of a ferrous object; determining an initial vertical position of the ferrous object, the initial vertical position comprising the vertical position of the at least one magnetic sensor related to the peak signal power value; and determining a horizontal position of the ferrous object comprising a horizontal distance from the at least one magnetic sensor related to the peak signal power value. - View Dependent Claims (19, 20)
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Specification