US-12625294-B1 - Buried utility marker devices, systems, and methods

US12625294B1US 12625294 B1US12625294 B1US 12625294B1US-12625294-B1

Abstract

Systems and methods for locating buried utilities in conjunction with associated electromagnetic marker devices are disclosed.

Inventors

Stephanie M. Bench
Mark S. Olsson

Assignees

SeeScan, Inc.

Dates

Publication Date: 20260512
Application Date: 20240502

Claims (16)

1 . A marker device embedded utility pipe, comprising: an elongate pipe or tube; and a plurality of marker devices disposed along or within the length of the pipe or tube, each marker device comprising: a marker device antenna; and an electronic circuit operatively coupled to the marker device antenna, the electronic circuit including: a first resonant circuit formed with the marker device antenna for receiving an excitation signal at a frequency from a marker excitation device; a power circuit for converting the excitation signal to a power supply for powering the electronic circuit; a processing element for generating an output signal responsive to the excitation signal; and a second resonant circuit for providing the output signal to the marker device antenna; wherein the output signal is generated at one or more frequencies different from the frequency of the excitation signal.
2 . The utility pipe of claim 1 , wherein the plurality of marker devices are configured to be simultaneously energized in response to receiving the excitation signal.
3 . The utility pipe of claim 1 , wherein the plurality of marker devices are configured to be sequentially energized in response to receiving the excitation signal.
4 . The utility pipe of claim 1 , wherein the plurality of marker devices are configured to be selectively energized based on one or more of a frequency, duty cycle, and coding of the excitation signal.
5 . The utility pipe of claim 1 , wherein the pipe or tube is comprised of a non-conductive material.
6 . A buried utility, comprising: an elongate hollow pipe or tube; and a plurality of marker devices disposed along the pipe or tube, each marker device comprising: a marker device antenna; and an electronic circuit operatively coupled to the marker device antenna, the electronic circuit including: a first resonant circuit formed with the marker device antenna for receiving an excitation signal at a frequency from a marker excitation device; a power circuit for converting the excitation signal to a power supply for powering the electronic circuit; and a processing element for generating an output signal responsive to the excitation signal, and a second resonance circuit for providing the output signal to the marker device antenna; wherein the output signal is generated at one or more frequencies different from the frequency of the excitation signal.
7 . A ground stake marker device, comprising: a housing shaped in the form of a stake; a marker device antenna, disposed in the housing, comprising a plurality of turns; and one or more electronic circuits operatively coupled to one or more sections of the marker device antenna, the electronic circuits including: a first resonant circuit formed with the marker device antenna section for receiving an excitation signal at a first frequency from a marker excitation device; a power circuit for converting the excitation signal to a power supply for powering the electronic circuit; a processing element for generating an output signal responsive to the excitation signal; and a second resonant circuit for providing the output signal to the marker device antenna; wherein the output signal is generated at a second frequency different from the first frequency.
8 . The ground stake marker device of claim 7 , wherein the housing includes a pointed end for being pushed or hammered into the ground, and wherein the housing is sealed to prevent ingress of environmental solid and liquid contaminants upon underground burial.
9 . The ground stake marker device of claim 8 , wherein the stake-shaped housing includes a dielectric layer for reducing capacitive coupling to the ground or other environment in which the ground stake marker device is embedded.
10 . The ground stake marker device of claim 9 , wherein the dielectric layer is comprised of one or more of polypropylene, polyethylene, polystyrene, and polytetrafluoroethylene.
11 . A pipe sleeve marker device, comprising: one or more pipes or tubes; a housing shaped to fit at least partially around the pipe or tube; and a plurality of marker devices disposed in the housing, each comprising: a marker device antenna; an electronic circuit operatively coupled to the marker device antenna, the electronic circuit including: a first resonant circuit formed with the marker device antenna for receiving an excitation signal at a first frequency from a marker excitation device; a power circuit for converting the excitation signal to a power supply for powering the electronic circuit; and a processing element for generating an output signal responsive to the excitation signal, and a second resonant circuit for providing the output signal to the marker device antenna; wherein the output signal is generated at a second frequency different from the first frequency.
12 . The pipe sleeve marker device of claim 11 , wherein the housing is configured as a pipe coupler fitting having two or more ends shaped to fit over or couple between two pipe sections of the pipe or tub, the housing formed to enclose the marker device antenna and electronic circuit from ingress of environmental solid and liquid contaminants upon underground burial and/or to prevent detuning of the pipe sleeve marker device.
13 . The marker device embedded pipe of claim 12 , wherein the pipe coupler-shaped housing includes a dielectric layer for reducing capacitive coupling to the ground or other environment in which the pipe sleeve marker device is embedded.
14 . A buried utility marker device, comprising: a circular shaped hollow housing; a marker device loop antenna, including at least one turn of a high conductivity material, positioned within the housing and environmentally sealed by the housing; and an electronic circuit positioned within the housing and operatively coupled to the marker device antenna, the electronic circuit including: a first resonant circuit formed with the marker device antenna for receiving an excitation signal at a first frequency from a marker excitation device; a power circuit for converting the excitation signal to a power supply for powering the electronic circuit; a processing element for generating an output signal responsive to the excitation signal; and a second resonant circuit for providing the output signal to the marker device antenna for transmission therefrom.
15 . The marker device of claim 14 , wherein the antenna consists of a single turn.
16 . The marker device of claim 14 , further including an elongate pipe or tube, wherein the marker device is positioned on or in the pipe or tube.

Description

FIELD This disclosure relates generally to apparatus, systems, and methods for locating hidden or buried objects using associated marker devices. More specifically, but not exclusively, the disclosure relates to apparatus, systems, and methods for locating buried utilities in conjunction with associated electromagnetic marker devices, which may be used in conjunction with electromagnetic utility locators. BACKGROUND The evolving complexity of infrastructure often requires precise location and identification of utility lines (e.g., underground power lines, gas lines, phone lines, fiber optic cable conduits, cable television (CATV) cables, sprinkler control wiring, water pipes, sewer pipes, etc.) for purposes of repair, enhancement, and/or replacement. Such utility lines, collectively and individually referred to herein as “buried objects” or “buried utilities,” may be buried in the ground and/or otherwise hidden from normal sight. Construction and/or excavation operations typically require the locations and/or identification of such utility lines be known so as to avoid costly and hazardous destruction of infrastructure (for example, so that a buried natural gas line is not ruptured during excavation of the ground for work on other utilities). In utility locating operations (also denoted as “locates” for brevity), one or more locating devices, also referred to herein as “buried utility locators,” “utility locators,” or simply “locators” for brevity, may be carried and moved about a locate area to detect, process, and/or record magnetic field signals for use in determining information associated with the utilities and/or other conductors in the ground. For example, one or more locators may be moved over the ground or other surface by an operator, with each locator receiving magnetic field signals emitted from one or more utilities. In one or more processing elements of the locator, the magnetic field signals are then processed to determine information about the buried utility, such as its position relative to the ground surface, depth, type of utility, geographical location, and the like. If the buried utilities are conductors that carry their own alternating current electrical signal, they can be traced by detecting emitted magnetic field signals at their correspondingly energized frequency or frequencies, such as 50 or 60 Hz, or harmonics thereof, from underground power cables. This is commonly known as “passive locating” (i.e., detecting magnetic field signals emitted from currents flowing in a utility due to a signal applied to the utility, as in the case of an electrical power signal, or induced in the utility from electromagnetic radiation from power lines, radio transmitters, or other signal sources). Signals may also be coupled to the utility by a user during a locate operation. These signals have a predefined frequency or frequencies, and may be generated in a device known in the field as a locate transmitter or “transmitter” for short. The output of the transmitter may be directly, inductively, or capacitively coupled to the utility to induce current flow therein. This type of locating is commonly known as “active locating.” In addition, in some locating operations, a device known as a sonde, which includes a magnetic dipole antenna and signal generation module, commonly powered by a battery, is inserted into a pipe, conduit, or other cavity and generates a dipole magnetic field signal that can be detected by the locator. Some locate operations use two or more of these locating techniques at a time, while others rely on a single emitted signal to determine buried utility information. Portable utility locators typically include one or more antennas that are used to detect the magnetic field signals emitted by buried pipes and cables and/or by sondes that have been inserted into pipes. In addition to the above magnetic field signals, some underground utility installations use marker devices placed adjacent to the utilities. Such marker devices are typically passive markers including a single resonant circuit for operating in a resonance mode responsive to a signal transmitting electromagnetic energy at a specific frequency, which is expected to be re-transmitted at the same frequency for detection of such marker devices. These marker devices lack control over the received electromagnetic energy, which is often affected by its form factor, component construction, manufacturing tolerances, underground environment (e.g., wet or otherwise conductive soil) where the marker devices are placed, etc. This can negatively affect performance of such marker devices and result in an output signal (re-transmitted signal) having a gradually decayed amplitude often undetectable by a receiver (e.g., locator antenna) or detectable, occasionally, with a limited signal range requiring close coupling with the receiver. Further, re-transmission of electromagnetic energy, from the marker device to the receiver, at the same