Enhanced precise location
First Claim
Patent Images
1. A line locator, comprising:
- a plurality of coil detectors, each of the plurality of coil detectors oriented to measure a component of an electromagnetic field, wherein the plurality of coil detectors comprise a first coil detector and a top coil detector;
circuitry coupled to receive signals from the plurality of coil detectors and provide quadrature signals indicating a complex electromagnetic field strength;
a position locator for indicating a position of the line locator;
a processor coupled to receive the complex electromagnetic field strength and the position and calculate values related to a target line;
a memory configured to store instructions; and
a display coupled to the processor, the display indicating to a user the values related to the target line,wherein the processor executes the instructions for performing the following;
modeling an expected complex field strength corresponding to complex field strengths and a phase error measured at the plurality of coil detectors at each of a plurality of positions determined by the position locator with the target line and a hypothesized number of bleedover cables to form a set of hypothesized values corresponding to a set of individual models for the target line for each of the hypothesized number of bleedover cables,wherein modeling uses a phase error function of locations, current and phase of each line including the target line and the bleedover cables, and an estimation of a current attenuation at two nearest side tones to update a fit factor, the side tones defined by a carrier frequency and a modulation frequency;
determining which of the set of individual models is a best model; and
determining parameters related to the target line from the best model.
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Abstract
A line locator includes a signal detector to detect signals from an underground line; an error modeler that models a phase error in the signal from neighboring underground lines; and an enhanced electromagnetic field modeler that provides a location of the underground line based on the signal and a result from the error modeler.
20 Citations
51 Claims
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1. A line locator, comprising:
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a plurality of coil detectors, each of the plurality of coil detectors oriented to measure a component of an electromagnetic field, wherein the plurality of coil detectors comprise a first coil detector and a top coil detector; circuitry coupled to receive signals from the plurality of coil detectors and provide quadrature signals indicating a complex electromagnetic field strength; a position locator for indicating a position of the line locator; a processor coupled to receive the complex electromagnetic field strength and the position and calculate values related to a target line; a memory configured to store instructions; and a display coupled to the processor, the display indicating to a user the values related to the target line, wherein the processor executes the instructions for performing the following; modeling an expected complex field strength corresponding to complex field strengths and a phase error measured at the plurality of coil detectors at each of a plurality of positions determined by the position locator with the target line and a hypothesized number of bleedover cables to form a set of hypothesized values corresponding to a set of individual models for the target line for each of the hypothesized number of bleedover cables, wherein modeling uses a phase error function of locations, current and phase of each line including the target line and the bleedover cables, and an estimation of a current attenuation at two nearest side tones to update a fit factor, the side tones defined by a carrier frequency and a modulation frequency; determining which of the set of individual models is a best model; and determining parameters related to the target line from the best model. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of locating an underground line, comprising:
- measuring an electromagnetic field using a plurality of coil detectors, each of the plurality of coil detectors oriented to measure a component of an electromagnetic field, wherein the plurality of coil detectors comprise a first coil detector and a top coil detector;
modeling, using a processor, a phase error based on the presence of lines neighboring the underground target line, wherein modeling uses a phase error function of locations, current and phases of each line including the underground target line and the neighboring lines, and an estimation of a current attenuation at two nearest side tones to update a fit factor, the side tones defined by a carrier frequency and a modulation frequency; and
utilizing the phase error in an enhanced electromagnetic field model to locate the target line. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
- measuring an electromagnetic field using a plurality of coil detectors, each of the plurality of coil detectors oriented to measure a component of an electromagnetic field, wherein the plurality of coil detectors comprise a first coil detector and a top coil detector;
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50. A line locator, comprising:
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a signal detector to detect signals from an underground line;
the signal detector comprising;a plurality of coil detectors, each of the plurality of coil detectors oriented to measure a component of an electromagnetic field, wherein the plurality of coil detectors comprise a first coil detector and a top coil detector; an error modeler that models a phase error in the signal from neighboring underground lines, wherein the error modeler uses a phase error function of locations, current and phase of each line including the underground line and the neighboring underground lines, and an estimation of a current attenuation at two nearest side tones to update a fit factor, the side tones defined by a carrier frequency and a modulation frequency; and an enhanced electromagnetic field modeler that provides a location of the underground line based on the signal and a result from the error modeler. - View Dependent Claims (51)
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Specification