Electromagnetic target discriminator sensor system and method for detecting and identifying metal targets
First Claim
1. A system for detecting a visually obscured object or an underground void, said system comprising:
- means for generating a first signal and a second signal from induced eddy currents;
means for determining if the first signal is greater than the second signal, the first signal is less than the second signal, and if the first signal is approximately equal to the second signal; and
means for determining the detection of the visually obscured object if the first signal is greater than the second signal, the detection of the underground void if the first signal is less than the second signal, and the non-detection of the visually obscured object or the underground void if the first signal is approximately equal to the second signal.
1 Assignment
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Accused Products
Abstract
A time-domain electromagnetic target discriminator (ETD) sensor system and method are provided capable of measuring a metal target'"'"'s time decay response based on the physical parameters of the metal target and its environment and for identifying the metal target. The ETD sensor system includes a pulse transmitter connected to a receiver via a data acquisition and control system. The transmitter and receiver include coil configurations for placement in proximity to a visually obscured, e.g., buried, metal target (or underground void) for inducing eddy currents within the metal target. The ETD sensor system measures the eddy current time decay response of the metal target in order to perform target recognition and classification. The identification process entails comparing the metal target'"'"'s (or, underground void or other object'"'"'s) time decay response with a library of normalized object signatures, e.g., time decay responses and other characteristics.
52 Citations
45 Claims
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1. A system for detecting a visually obscured object or an underground void, said system comprising:
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means for generating a first signal and a second signal from induced eddy currents;
means for determining if the first signal is greater than the second signal, the first signal is less than the second signal, and if the first signal is approximately equal to the second signal; and
means for determining the detection of the visually obscured object if the first signal is greater than the second signal, the detection of the underground void if the first signal is less than the second signal, and the non-detection of the visually obscured object or the underground void if the first signal is approximately equal to the second signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for detecting a visually obscured object or underground void, said method comprising the steps of:
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scanning a region with a sensor system having a transmitter coil, a first receiver coil and a second receiver coil for inducing eddy currents within the visually obscured object, the underground void, and/or soil;
converting the eddy currents received by the first receiver coil to a first signal and converting the eddy currents received by the second receiver coil to a second signal;
subtracting the first signal from the second signal to generate a time decay response signal;
determining whether the first signal is greater than the second signal, the first signal is less than the second signal, or if the first signal is approximately equal to the second signal; and
determining the detection of the visually obscured object if the first signal is greater than the second signal, the detection of the underground void if the first signal is less than the second signal, and the non-detection of the visually obscured object or the underground void if the first signal is approximately equal to the second signal. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A sensor system for detecting visually obscured objects and underground voids by inducing eddy currents in same, said antenna comprising:
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a transmitter coil;
two receiver coils surrounded by the transmitter coil and being at least one receiver coil diameter apart, each of said two receiver coils configured for converting the eddy currents into a first signal and a second signal; and
a differential amplifier for subtracting the first signal from the second signal. - View Dependent Claims (22, 23, 24)
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25. An algorithm for optimizing target characterization of a visually obscured object upon detection of said visually obscured object by a metal detector sensor system having a transmitter and a receiver, said algorithm comprising the steps of:
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a. adjusting a first parameter of said metal detector sensor system and collecting a data set using the receiver;
b. analyzing the collected data set to determine at least one measurement of a time decay response corresponding to the object; and
c. adjusting a second parameter of said metal detector sensor system, collecting a data set using the receiver, and returning to step (b), if the determined at least one measurement is outside a predetermined range. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. An algorithm for optimizing target characterization of a visually obscured object upon detection of said visually obscured object by a detector having a transmitter and a receiver, said algorithm comprising the steps of:
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a. collecting a plurality of data sets from a plurality of respective receiver positions in proximity to the position of the visually obscured object using the detector; and
b. computing the plurality of data sets to derive a single data set. - View Dependent Claims (41, 42, 43, 44, 45)
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Specification