Method and apparatus for digital detection of electronic markers using frequency adaptation
First Claim
Patent Images
1. A method of locating one or more markers, comprising:
- generating a series of electromagnetic pulses by generating a transmit signal with resonant frequencies from at least one marker and applying the transmit signal to an electronic marker, wherein the generation of the transmit signal includes;
determining a marker or more active markers;
determining a marker transmit signal to activate the one or more active markers from a frequency, field strength, and phase, wherein the marker transmit signal is phase shifted to provide a delay phase of substantially zero at the end of the electromagnetic pulse;
summing the marker transmit signal to form a digital transmit signal; and
converting the digital transmit signal to form the transmit signal;
receiving signals as a function of time between application of the pulses;
averaging the signals over a predetermined number of pulses to obtain an average decay signal;
initially determining a frequency, field strength, and phase for responses from the one or more markers;
accurately determining the frequency, field strength, and phase by successive elimination of a contribution from each of the one or more markers; and
refining the electromagnetic pulses in order to provide resonant frequencies for each of the one or more markers.
4 Assignments
0 Petitions
Accused Products
Abstract
An electronic marker locator with a digital architecture for providing accurate and consistent estimation of the signal strength is presented. The marker locator includes a Digital Phase-Locked Loop (DPLL) structure. The electronic marker locator transmits known and adjustable frequency bursts corresponding to the markers to be located while synchronously capturing the signals returned from the markers.
-
Citations
15 Claims
-
1. A method of locating one or more markers, comprising:
-
generating a series of electromagnetic pulses by generating a transmit signal with resonant frequencies from at least one marker and applying the transmit signal to an electronic marker, wherein the generation of the transmit signal includes; determining a marker or more active markers; determining a marker transmit signal to activate the one or more active markers from a frequency, field strength, and phase, wherein the marker transmit signal is phase shifted to provide a delay phase of substantially zero at the end of the electromagnetic pulse; summing the marker transmit signal to form a digital transmit signal; and converting the digital transmit signal to form the transmit signal; receiving signals as a function of time between application of the pulses; averaging the signals over a predetermined number of pulses to obtain an average decay signal; initially determining a frequency, field strength, and phase for responses from the one or more markers; accurately determining the frequency, field strength, and phase by successive elimination of a contribution from each of the one or more markers; and refining the electromagnetic pulses in order to provide resonant frequencies for each of the one or more markers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A marker locator for detecting and determining the location of one or more markers that identify a utility line, the locator comprising:
-
an antenna configured to provide a series of electromagnetic pulse and to receive signals as a function of time between application of the pulses, wherein the series of electromagnetic pulses are generated by generating a transmit signal with resonant frequencies from at least one marker and applying the transmit signal to an electronic maker, wherein the generation of the transmit signal includes; determining one or more active markers; determining a marker transmit signal to activate the one or more active markers from a frequency, field strength, and phase, wherein the market transmit signal is phase shifted to provide a delay phase of substantially zero at the end of the electromagnetic pulse, summing the marker signal to form a digital transmit signal, and converting the digital transmit signal to form the transmit signal; and a processor configured to average the signals over a predetermined number of pulses to obtain an average decay signal, initially determine a frequency, field strength, and phase for responses from the one or more marker, and accurately determine the frequency, field strength, and phase by successive elimination of a contribution from each of the one or more markers.
-
-
10. A method of locating one or more markers, comprising:
-
generating a series of electromagnetic pulses can excite multiple types of markers and each type of marker represents a different type of utility line; receiving signals as a function of time between application of the pulses, wherein the signals are from one or more markers identifying at least one utility line; averaging the signals over a predetermined number of pulses to obtain an average decay signal; initially determining a frequency, field strength, and phase for responses from the one or more markers, wherein initially determining the frequency, the field strength, and the phase includes; performing a fast Fourier transform of the average decay signal, and obtaining initial determinations of the frequency, field strength, and phase of at least one marker from parameters determined in the fast Fourier transform; accurately determining the frequency, the field strength, and the phase by successive elimination of a contribution from each of the one or more markers, wherein the determining includes; determining a dominant marker from the initial determinations, calculating a response from the dominant marker, removing the response from the dominant marker from the average decay signal, and determining the frequency, field strength, and phase of at least one marker from the average decay signal with the response from the dominant marker removed; and refining the electromagnetic pulses in order to provide resonant frequencies for each of the one or more markers, wherein the accurate determining and the refining assists in the capability to distinguish a particular type of one or more markers from the different types of markers. - View Dependent Claims (11, 12, 13, 14)
-
-
15. The marker locator for detecting and determining the location of one or more markers that identify a utility line, the locator comprising:
-
an antenna that provides a series of electromagnetic pulses and receives signals as a function of time between application of the pulses, wherein these pulses can excite multiple types of markers and each type of markers represents a different type of utility line and the signals are from one or more markers identifying at least one utility line; and a processor configured to; average the signals over a predetermined number of pulses to obtain an average decay signal, initially determine a frequency, field strength, and phase for responses from the one or more markers by performing a fast Fourier transform of the average decay signal and by obtaining initial determinations of the frequency, field strength, and phase of at least one marker from parameters determined in the fast Fourier transform, and accurately determine the frequency, field strength, and phase by successive elimination of a contribution from each of the one or more markers by determining a dominant marker from the initial determinations, by calculating a response from the dominant marker, by removing the response from the dominant marker from the average decay signal, and by determining the frequency, field strength, and phase of at least one marker from the average decay signal with the response from the dominant marker removed, wherein the accurate determining assists in distinguishing a particular type of marker from the different types of markers.
-
Specification