U.S. patent application number 15/225623 was filed with the patent office on 2017-04-27 for sonde-based ground-tracking apparatus and methods.
The applicant listed for this patent is Sequoyah Aldridge, Ryan B. Levin, Mark S. Olsson. Invention is credited to Sequoyah Aldridge, Ryan B. Levin, Mark S. Olsson.
Application Number | 20170115424 15/225623 |
Document ID | / |
Family ID | 50484787 |
Filed Date | 2017-04-27 |
United States Patent
Application |
20170115424 |
Kind Code |
A1 |
Olsson; Mark S. ; et
al. |
April 27, 2017 |
SONDE-BASED GROUND-TRACKING APPARATUS AND METHODS
Abstract
A ground tracking system includes a ground follower assembly
including a sonde for use with a locator or other device for
determining position, motion, and/or orientation information.
Inventors: |
Olsson; Mark S.; (La Jolla,
CA) ; Levin; Ryan B.; (San Diego, CA) ;
Aldridge; Sequoyah; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Olsson; Mark S.
Levin; Ryan B.
Aldridge; Sequoyah |
La Jolla
San Diego
San Diego |
CA
CA
CA |
US
US
US |
|
|
Family ID: |
50484787 |
Appl. No.: |
15/225623 |
Filed: |
August 1, 2016 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13841879 |
Mar 15, 2013 |
9411067 |
|
|
15225623 |
|
|
|
|
61786350 |
Mar 15, 2013 |
|
|
|
61786385 |
Mar 15, 2013 |
|
|
|
61781889 |
Mar 14, 2013 |
|
|
|
61783011 |
Mar 14, 2013 |
|
|
|
61784854 |
Mar 14, 2013 |
|
|
|
61779830 |
Mar 13, 2013 |
|
|
|
61615810 |
Mar 26, 2012 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01V 3/12 20130101; G01V
3/10 20130101; G01V 3/15 20130101 |
International
Class: |
G01V 3/10 20060101
G01V003/10 |
Claims
1. A ground following tracking apparatus for use with an electronic
device, comprising: a ground follower element including a sonde for
generating a magnetic dipole field; and an attachment mechanism for
coupling the ground following tracking apparatus to the electronic
device.
2. The apparatus of claim 1, wherein the electronic device is a
magnetic-sensing buried utility locator.
3. The apparatus of claim 1, wherein the ground follower element
includes a wheel.
4. A system for locating buried utilities, comprising: a utility
locator including a plurality of magnetic field antennas and a
circuit for processing output signals from the plurality of
antennas to determine information about a hidden or buried utility;
and an omni-inducer wheel apparatus coupled to the locator for
generating magnetic field signals for induction to the hidden or
buried utilities.
5. A method of tracking ground movement using a buried utility
locator, comprising: generating, from a rolling element including a
sonde a magnetic dipole field; sensing, in the buried utility
locator, the magnetic dipole field; and determining, based at least
in part on the magnetic dipole field, motion, position, or
orientation information of the buried utility locator.
6. The method of claim 5, wherein the rolling element includes one
or more wheels.
7. The method of claim 6, wherein the sonde is disposed in one of
the one or more wheels.
8. The method of claim 6, further including determining one or more
characteristics of a surface over which the buried utility locator
is moved based on the motion, position, or orientation
information.
9. The method of claim 8, wherein the motion, position, or
orientation information comprises three-dimensional motion
information or three-dimensional position information.
10. The method of claim 8, wherein the motion, position, or
orientation information comprises information associated with a
translation movement of the locator relative to a surface over
which the locator is moved.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority to
co-pending U.S. patent application Ser. No. 13/841,879, filed Mar.
15, 2013, entitled GROUND-TRACKING SYSTEMS AND APPARATUS, which
claims priority under 35 U.S.C. .sctn.119(e) to U.S. Provisional
Patent Application Ser. No. 61/615,810, filed Mar. 26, 2012,
entitled GROUND-TRACKING SYSTEMS AND APPARATUS, U.S. Provisional
Patent Application Ser. No. 61/781,889, filed Mar. 14, 2013,
entitled OMNI-INDUCER TRANSMITTING DEVICES AND METHODS, U.S.
Provisional Patent Application Ser. No. 61/783,011, filed Mar. 14,
2013, entitled MULTI-FREQUENCY LOCATING SYSTEMS AND METHODS, U.S.
Provisional Patent Application Ser. No. 61/786,385, entitled DUAL
ANTENNA SYSTEMS WITH VARIABLE POLARIZATION, filed Mar. 15, 2013,
U.S. Provisional Patent Application Ser. No. 61/784,854, filed Mar.
14, 2013, entitled SELF-GROUNDING TRANSMITTING PORTABLE CAMERA
CONTROLLER FOR USE WITH PIPE INSPECTION SYSTEM, U.S. Provisional
Patent Application Ser. No. 61/786,350, filed Mar. 15, 2013,
entitled USER INTERFACES FOR UTILITY LOCATORS, and U.S. Provisional
Patent Application Ser. No. 61/779,830, filed Mar. 13, 2013,
entitled GRADIENT ANTENNA COILS AND ARRAYS FOR USE IN LOCATING
SYSTEMS. The content of each of these applications is incorporated
by reference herein in its entirety for all purposes.
FIELD
[0002] This disclosure relates generally to ground tracking systems
and apparatus for use with buried object locators. More
specifically, but not exclusively, this disclosure relates to a
ground tracking system for providing signals associated with
position and/or motion information of a coupled buried object
locator, relative to the surface of the ground.
BACKGROUND
[0003] There are many situations where it is desirable to locate
buried utilities or other objects, such as pipes and cables. For
example, prior to starting any new construction that involves
excavation, it is important to locate buried objects and
underground utilities, such as power lines, gas lines, phone lines,
fiber optic cable conduits, cable television (CATV) cables,
sprinkler control wiring, water pipes, sewer pipes, and the like
(collectively and individually referred to herein as "utilities" or
"objects"). As used herein, the term "buried" refers not only to
objects below the surface of the ground, but also to objects
located inside walls, between floors in multi-story buildings, cast
into concrete slabs, or otherwise obscured, covered, or hidden from
direct view or access.
[0004] Location of these buried objects may be important for cost,
time, and safety reasons. For example, if a backhoe or other
excavation equipment hits a high voltage line or a gas line,
serious injury may result. Further, severing water mains and sewer
lines leads to messy cleanups.
[0005] Buried objects can be located by sensing an emitted
electromagnetic signal. For example, some buried cables, such as
electric power lines, are already energized and emit their own long
cylindrical electromagnetic field. In other cases, the buried
object may be energized to produce electromagnetic radiation. For
example, an external electrical power source having, for example, a
frequency in a range of approximately 22 Hz to 500 kHz may be used
to energize a buried object such as a pipe or conduit. Location of
buried long conductors is often referred to as "line tracing," and
the results may be referred to as a "locate."
SUMMARY
[0006] The present disclosure relates generally to systems,
methods, and apparatus for locating buried objects (locators). More
specifically, but not exclusively, the disclosure relates to ground
tracking devices configured for use with locators or other
measurement devices to follow a ground or other surface and provide
signals associated with position and/or motion information in one
or more axes of motion that may be used by the locator to generate
position, motion, and/or orientation information.
[0007] Various additional aspects, features, functions, and details
are further described below in conjunction with the appended
Drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates details of an embodiment of a ground
tracking system in use in accordance with aspects of the present
disclosure.
[0009] FIG. 2A is the ground tracking system embodiment of FIG. 1,
illustrating details thereof;
[0010] FIG. 2B is a side view of the embodiment from FIG. 1 with a
dipole beacon in or on the wheel assembly;
[0011] FIG. 2C is an isometric illustration of a dipole beacon
embodiment installed on the yoke or arms of the wheel assembly;
[0012] FIG. 2D is a detailed illustration of the yoke embodiment
from FIG. 2C;
[0013] FIG. 2E is a bottom view illustration to the yoke embodiment
from FIG. 2C;
[0014] FIG. 3 illustrates a ground tracking system embodiment of
FIG. 1, elevated above the ground or other surface;
[0015] FIG. 4 is an enlarged detailed rear view of an embodiment of
a ground follower assembly of FIGS. 1-3.
[0016] FIG. 5A illustrates details of an embodiment of the ground
follower assembly of FIGS. 1-4 anchored to an antenna node;
[0017] FIG. 5B illustrates a ground tracking embodiment anchored to
an antenna node;
[0018] FIG. 6 is an exploded view of the ground tracking system
embodiment of FIGS. 1 and 2, illustrating details thereof;
[0019] FIG. 7 is an exploded view of an embodiment of an annular
race assembly of FIG. 6, illustrating details thereof;
[0020] FIG. 8 is an enlarged detailed rear view of an embodiment of
a wheel assembly of FIGS. 2-6;
[0021] FIG. 9 is an exploded view of the wheel assembly embodiment
of FIGS. 2-6, and 8, illustrating details thereof;
[0022] FIG. 10 is an enlarged detailed side view of the wheel
assembly embodiment of FIGS. 2-6, and 8-9;
[0023] FIG. 11 is an enlarged vertical section view of the wheel
assembly embodiment, taken along line 11-11 of FIG. 10;
[0024] FIG. 12 is an enlarged detailed side view of an embodiment
of a left floating wheel of FIGS. 8-11;
[0025] FIG. 13 is an exploded view of the left floating wheel
embodiment of FIG. 12, illustrating details thereof;
[0026] FIG. 14 is a block diagram illustrating an embodiment of a
ground tracking system in accordance with aspects of the present
disclosure;
[0027] FIG. 15A illustrates an embodiment of a direct excitation
circuit for inducing current in the dipole beacon(s);
[0028] FIG. 15B illustrates an embodiment of a circuit using
primary coils for inducing current in a secondary current of the
dipole beacon(s);
[0029] FIG. 16A illustrates an alternative dipole beacon
configuration embodiment;
[0030] FIG. 16B illustrates an alternative dipole beacon
configuration embodiment;
[0031] FIG. 16C illustrates an alternative dipole beacon
configuration embodiment;
[0032] FIG. 17A illustrates a locator embodiment with an
alternative ground tracking yoke structure configuration
embodiment;
[0033] FIG. 17B illustrates the embodiment from FIG. 17A with a
tripod accessory;
[0034] FIG. 17C illustrates the embodiment from FIG. 17B with
another ground tracking yoke structure configuration;
[0035] FIG. 18 illustrates a dragging dipole beacon embodiment;
[0036] FIG. 19A is an illustration of a snap on dipole beacon
embodiment;
[0037] FIG. 19B illustrates the embodiment from FIG. 19A with the
beacon rotated as it may move across the ground or operating
surface;
[0038] FIG. 19C illustrates the beacon embodiment from FIG. 19A in
detail;
[0039] FIG. 20A is an illustration of an omni-directional inducer
wheel embodiment connected to a locator device;
[0040] FIG. 20B is an illustration of the embodiment from FIG. 20A
from a below perspective;
[0041] FIG. 20C is an illustration of the embodiment from FIG. 20A
demonstrating the use of a stowage clip;
[0042] FIG. 20D is an illustration of an omni-inducer wheel
embodiment;
[0043] FIG. 20E is an illustration of the embodiment from FIG. 20A
in use;
[0044] FIG. 21 is an illustration of an alternative omni-inducer
wheel embodiment with multiple omni-inducer wheel assemblies;
[0045] FIG. 22 is an illustration of an alternate ground tracking
embodiment that may be attached to or carried by a user; and
[0046] FIG. 23 is an illustration of an alternate ground tracking
embodiment that may be attached to a vehicle.
DETAILED DESCRIPTION OF EMBODIMENTS
Overview
[0047] The present disclosure relates generally to systems,
methods, and apparatus for locating buried objects. More
specifically, but not exclusively, the disclosure relates to a
ground tracking device configured with a locator to follow the
ground or other surface, and provide position and/or motion
information, including measurements regarding changes in heading of
the ground tracking device (e.g., translational and rotational
movement with respect to the ground/other surface).
[0048] In accordance with one aspect of the invention, the ground
tracking device may include at least one measurement device for
sensing motion and position in x, y and z dimensions in addition to
a time dimension. The measurement device may sense a rotational
motion of a ground tracking device (or any part of the ground
tracking device) about a substantially fixed ground reference
point, and one or more output signals may include one or more
signals corresponding to the rotational motion about the
substantially fixed ground point. The measurement device may
also/alternatively sense a translational motion of the ground
tracking device, or a part thereof, over the ground/surface, and
the one or more signals may include one or more signals
corresponding to the translational motion. The measurement device
may also/alternatively sense an up and/or down motion of the ground
tracking device, or a part thereof, relative to the ground/surface,
and the one or more signals may include one or more signals
corresponding to the up and/or down motion. Alternately, or in
addition, the measurement device may sense a swivel motion of the
ground tracking device, or a part thereof, with respect to the
ground/surface or another part of the ground tracking device, and
the one or more signals may include one or more signals
corresponding to the swivel motion. The measurement device may
sense, for example, vertical, horizontal or other movement and/or
orientation of a floating wheel with respect to another wheel
(e.g., the center wheel), and the one or more signals may include
one or more signals corresponding to the relative movement and/or
orientation of the floating wheel.
[0049] In accordance with another aspect, the ground tracking
device may include a ground follower assembly coupled to an antenna
node. The ground follower assembly may be configured to generate
one or more output signals corresponding to motion and/or distance
of the locator device over a ground or surface. The ground follower
assembly may further include a wheel assembly coupled to an antenna
node of a locator with a coupling element, such as a yoke element,
which may be removably attached to a race ring assembly mounted on
the antenna node. For example, the yoke may be coupled to a pair of
hinges disposed on the race ring assembly.
[0050] In accordance with one aspect, the disclosure relates to a
wheel assembly which may include one or more wheels which maintain
contact with the ground simultaneously. The wheel assembly may
include, for example, a left floating wheel, a right floating
wheel, and a center wheel. Each wheel may turn in a forward or
backward direction
[0051] In accordance with another aspect, the wheel assembly and/or
other components of the ground tracking device may include various
sensors for collecting movement and position information. Examples
of sensors include one or more compasses, accelerometers, magnets,
GPS receivers, gyroscopes, barometers, magnetic field, and other
sensors. Any number of these sensors may be used to collect
information regarding movement or position of each individual wheel
and/or the relative movement or position of two or more wheels
(e.g., the left and right floating wheels) with respect to each
other or another wheel (e.g., the center wheel). For example,
relative turning of the left and right floating wheels may be
measured with respect to the center wheel, and different outputs
may be determined depending on the direction of the respective
turning, and also distance traveled by each wheel over a period of
time. When the wheel assembly travels over a surface along an arc
(e.g., a clockwise arc pathway), for instance, the outside wheel
(e.g., the left floating wheel) normally must turn more than the
inside wheel (e.g., the right floating wheel) because it travels a
greater distance during the same amount of time. The traveled
pathway may be determined, for example, by considering both the
difference between the distances traveled by each wheel and the
fixed distance separating the wheels. When the wheel assembly
rotates/pivots about a point on a surface below the center of the
wheel assembly (e.g., in a clockwise direction), for instance, the
outside wheels normally must turn in opposite directions while the
center wheel does not turn. The amount of rotation may be
determined, for example, by considering the amount of turning by
each wheel and the circumference of each wheel. Knowing the
relative translational and rotational movement provides information
that may be used to track the relative direction and/or distance
traveled by the ground tracking device.
[0052] Tracked movement and position of the wheel assembly may be
used to track movement and position of an antenna node in a locator
assembly connected to the wheel assembly. For example, the locator
assembly and wheel assembly may be connected to each other via a
coupling element having a fixed length. Vertical and horizontal
differences between the position of the wheel assembly and the
locator assembly may be determined and used in association with
calculated position and motion of the wheel assembly to ascertain
the position and motion of the antenna node. For example, the
measured angle of magnetic field lines generated by an inductor
disposed in the wheel assembly may provide a relative angle of the
wheel assembly to the locator. In some embodiments, such an
inductor may include a magnetic dipole beacon such as a sonde.
Hereafter, the terms "inductor", "magnetic dipole beacon", "dipole
beacon", "beacon", or "sonde" may refer to the same concept.
Furthermore, corresponding compass readings from a compass in the
wheel assembly and a compass in the locator can also provide a
relative angular bearing between the wheel assembly and the
locator. By way of another example, relative magnetic field
strength measured at two antennas may provide a vertical height of
the locator from the wheel assembly.
[0053] In one aspect, the disclosure relates to a ground tracking
system. In an exemplary embodiment, a plurality of magnets may be
disposed within the floating wheels. One or more sensor elements,
such as three-axis accelerometers and one or more three-axis
compass sensors may be disposed in the wheel assembly to measure
the relative motion of each floating wheel and generate an output
signal corresponding to rotation, position, and/or other
information. The wheel assembly may include various circuit
elements including a central circular PCB and magnetic sensor
boards. The wheel assembly may further include one or more battery
elements, such as a C-cell battery, to provide power to various
circuit elements. The wheel assembly may optionally include a
gyroscope, a barometer, and/or a tilt sensor. A High Q high
frequency sonde may be optionally included in the ground tracking
system.
[0054] In accordance with various other aspects, one or more
magnets may be disposed in left and right floating wheels and one
or more sensor elements, such as magnetic sensor elements, may be
disposed within the wheel assembly (e.g., in the center wheel) to
sense a rotation of left and right floating wheels, and to generate
one or more output signals based at least in part on the sensed
movement or position. The wheel assembly may further/alternatively
include a compass element configured to generate a compass output
signal corresponding to a position of the ground follower assembly.
The ground tracking device may also/alternatively include an
accelerometer (e.g., a three-axis accelerometer) that may be
configured to generate an output signal corresponding to a motion
of the ground follower assembly. A GPS receiver module or other
terrestrial or satellite position location device may
also/alternatively be included. The ground tracking device may
further/alternatively include one or more sensor elements and
associated hardware and signal processing circuits configured to
sense a rotation of one or more wheels associated with translation
motion, to sense tilt of the wheel assembly from a vertical plane
or the tilt of one wheel with respect to another wheel or the
vertical plane, to sense roughness of a surface, to sense steepness
of a surface, to sense sudden elevation changes of a surface (e.g.,
when the wheel assembly descends down or ascends up a curb or other
object), to sense acceleration up or down a surface, to sense
whether the wheel assembly is sliding against the surface, and to
sense other environmental conditions.
[0055] Other aspects relate to a ground tracking device comprising
one or more sensors configured to determine motion, position,
and/or orientation information relating to the ground tracking
device or a component of the ground tracking device. The motion,
position or orientation information may comprise any-dimension
motion, position or orientation information.
[0056] In accordance with one aspect, the one or more sensors
comprise one or more accelerometers, compasses, magnetic sensors,
GPS or other location-based receivers, or gyroscopes. The one or
more sensors may be configured to: generate one or more output
signals representative of a motion of the ground tracking device or
the component over a surface; generate one or more output signals
representative of a position and an orientation of the ground
tracking device or the component over a surface; measure a
translational movement of the ground tracking device or the
component relative to a surface; measure a rotational movement of
the ground tracking device or the component relative to a surface;
measure a position of a wheel relative to a position of a locator
assembly; measure an orientation of a wheel relative to a locator
assembly; measure an orientation of a wheel relative to a fixed
point on a surface; measure a direction of rotation and an amount
of rotation of a wheel relative to a fixed point on a surface;
measure a distance traveled by a wheel over a surface during a time
period; measure a direction a wheel is traveling at a point in
time; measure a movement of a first wheel relative to a movement of
a second wheel; measure respective movements of two wheels relative
to a movement of another wheel; measure a first direction in which
a first wheel turns and a second direction in which a second wheel
turns (e.g., when the first direction and the second direction are
different, the ground tracking device determines that the component
of the ground tracking device is rotating about a point on a
surface); and/or measure a first distance in which a first wheel
turns and a second distance in which a second wheel turns (e.g.,
when the first distance and the second distance are different, the
ground tracking device determines that the component of the ground
tracking device is traveling along an arc over a surface).
[0057] In accordance with another embodiment, the ground tracking
device may include a wheel assembly with a first outer wheel, a
second outer wheel and a center wheel. The center wheel may be
disposed between the first and second outer wheels, and the first
and second outer wheels may be floating wheels relative to the
center wheel and further configured to maintain contact with an
uneven surface. The first outer wheel may comprise a flexible
mechanism configured to permit the first outer wheel to move in a
vertical direction relative to the center wheel. The flexible
mechanism may comprise one or more spiral spokes.
[0058] The wheel assembly may also include some or all of the one
or more sensors, which are configured to: measure a position of a
wheel assembly relative to a position of a locator assembly;
measure an orientation of a wheel assembly relative to a locator
assembly; measure an orientation of a wheel assembly relative to a
fixed point on a surface; measure a direction of rotation and an
amount of rotation of a wheel assembly relative to a fixed point on
a surface; measure a distance traveled by a wheel assembly over a
surface during a time period; and/or measure a direction a wheel
assembly is traveling at a point in time.
[0059] The ground tracking device may further include a locator
assembly, a coupling element configured to couple the locator
assembly to the wheel assembly, and a circuit or other processing
element. The wheel assembly may comprise an inductor, and the
locator assembly may comprise one or more antenna nodes configured
to measure the magnetic field strength and one or more magnetic
field lines of the inductor. In such embodiments, an inductor may
refer to a magnetic dipole beacon such as a sonde. The coupling
element may be configured to permit the wheel assembly to swivel
around the locator assembly. The circuit may be configured to
determine an approximate height of a first antenna node from a
surface based on two measurements of the magnetic field strength of
the inductor at two different instances in time by a second antenna
node. In addition, or alternatively, the circuit may be configured
to determine a swivel angle based on an angle of the one or more
magnetic field lines relative to a reference plane.
[0060] In accordance with another embodiment, the ground tracking
device may include a circuit configured to determine one or more
characteristics of a surface based on the motion, position, or
orientation information. The one or more characteristics include
one or more of an elevation of particular points on the surface, a
terrain profile of the surface, a surface area of the surface, a
composition of the surface, and/or a contour of the surface across
a surface area.
[0061] In another embodiment, a rolling ground tracking device may
be configured to couple to a locator or other device and trail
behind the device to act as a ground tracking device, such as
described herein, and/or an induction device, to generate signals
for induction of signals into buried objects, or both. Examples of
induction device embodiments and details as may be combined with
the disclosures herein are described in, for example, co-assigned
U.S. Provisional Patent Application Ser. No. 61/781,889, filed Mar.
14, 2013, entitled OMNI-INDUCER TRANSMITTING DEVICES AND METHODS,
which is incorporated herein.
[0062] In another embodiment, a rolling or moving element, such as
a wheel, axle, or other rolling element, or bracket, swing arm, or
other moving element, may include one or more sondes. At least one
sonde may have an axis that is not coincident with the rolling
axis. The rolling element may be coupled to a buried object locator
or other instrument, tool, or device. The device may be configured
to track the position and/or rotation of one or more of the sondes
while rolling and measure its own movement over the ground relative
to the position or rotation. The device may also be configured to
detect induced signals from buried objects from transmitted signals
from the one or more rolling sondes.
[0063] In another embodiment, a rolling or moving element, such as
a wheel, axle, or other rolling element, or bracket, swing arm, or
other moving element, may include an orthogonal array of three
sondes. The axis of rotation may be positioned at approximately
equal angles to each antenna coil, and signals may be transmitted
from the sondes for use by a locator in determining rotation or
other motions.
[0064] In another embodiment, one or more batteries may be
configured to have a long axis that is coincident with the axis of
rotation of one or more of the rolling structures. The batteries
may be used in a wheel or other rolling element in various
embodiments.
[0065] In another embodiment, a connecting arm that is configured
to pivot with a pivoting assembly may be coupled around an axis,
such as a vertical axis, attached to a locator or other device. One
or more sondes may be disposed on or within the arm to determine
movement similarly to movement detection with respect to a rolling
element such as a wheel.
[0066] In another embodiment, a flexible connecting arm may be
disposed between the locator and a rolling element, such as a wheel
or axle, that includes a sonde array. Various lengths of flexible
arms may be used. The flexible arm may be flexible both in bending
and in twisting motions. The flexible arm may include both rigid
sections and pivoting joints.
[0067] In another embodiment, a flexible connecting arm may be
disposed between the locator and a rolling sonde array. A trailing
end of the connecting arm may be secured to the locator for
transport and storage.
[0068] In another embodiment, a detection circuit for sensing
movement or rotation and automatically waking up a coupled device,
such as a locator or sonde array, from a low power state or off
state may be included or coupled to a rolling element such as a
wheel or axle. Upon waking or powering up, the device, such as a
sonde array, may begin transmitting. Such a circuit may be used to
conserve power in a sonde array powered by a batteries and/or in a
coupled locator.
[0069] In another embodiment, two or more transmitting coils that
transmit at different frequencies may be included, such as in a
rolling device such as a wheel and/or a rolling sonde array
element. In another embodiment, two or more transmitting coils that
transmitting in a timed sequence may be included. In another
embodiment, two or more transmitting coils that are oriented
orthogonally to each other may be included. In another embodiment,
two or more transmitting coils that employ primary and secondary
coils on each axis may be included. In such a configuration, the
secondary coil may be part of a circuit that includes a capacitor.
In another embodiment, two or more transmitting coils that have a
resonant Q of greater than 10 may be included.
[0070] In another embodiment, a rechargeable battery may be
included. The rechargeable battery may be coupled to a sonde array
to provide power to the sonde array. The rechargeable battery
element may be configured, in conjunction with a circuit in the
rolling device, moving element, or sonde array, to be recharged by
inductive charging from an inductive charging device. In another
embodiment, the rechargeable battery may be configured, in
conjunction with a circuit in the rolling device, moving element,
or sonde array, to be charged from a USB port or other serial or
parallel data interface port.
[0071] In another embodiment, a wireless data module for providing
a data communications link from the rolling sonde array to the
locator may be included in the rolling element or sonde array. The
wireless link may be a Bluetooth, or Bluetooth LE link, or Wi-Fi or
other wireless communications link.
[0072] In another embodiment, two or more transmitting coils that
transmit in a specific phase relationship to each other may be
included in a rolling device or sonde array. The two or more
transmitting coils may be phase locked to one another. In another
embodiment, three or more transmitting coils that are all in phase
at a periodic interval of time may be included. In another
embodiment, two or more transmitting coils that use or are provided
with a signal using a single clock may be included. In another
embodiment, two or more transmitting coils that use a single clock
that is accurate to better than 20 ppm may be used. In another
embodiment, two or more transmitting coils of a sonde array that
are mounted inside an approximately spherical structure may be
used. In another embodiment a two or more wheeled structure or
device, each with one or more independently rotating transmitting
sondes, may be provided. The two or more rotating structures or
devices may be configured to be able to detect pivoting rotation
against the ground. In another embodiment, at least one 18650
rechargeable lithium battery may be used to power one or more
sondes.
[0073] In a rolling sonde array embodiment, sets of sonde transmit
frequencies may be, for example, 90 kHz, 91 kHz, 92 kHz, or 70 kHz,
80 kHz, 90 kHz.
[0074] Various embodiments in accordance with details of the
present disclosure may be used or combined with details of buried
object locators and/or sondes and associated components as
described in co-assigned applications. For example, various ground
tracking device embodiments in accordance with aspects disclosed
herein may be combined with details of locators and sondes such as
are described in U.S. Pat. Nos. 7,009,399, 7,332,901, 7,336,078,
7,443,154, 7,619,516, 7,733,077, 7,741,848, 7,755,360, 7,825,647,
7,830,149, U.S. Patent Publication 2011/0006772, and U.S. patent
application Ser. No. 13/161,183 (collectively referred to herein as
the "related applications"). The content of each of these patents,
publications and applications is incorporated by reference herein
in its entirety for all purposes.
[0075] Various other aspects of apparatus, devices, configurations,
and methods that may be used in ground tracking embodiments as
disclosed herein are described in U.S. patent application Ser. No.
13/677,223, filed Nov. 14, 2012, entitled MULTI-FREQUENCY LOCATING
SYSTEMS & METHODS, U.S. patent application Ser. No. 13/570,211,
filed Aug. 8, 2012, entitled PHASE-SYNCHRONIZED BURIED OBJECT
LOCATOR APPARATUS, SYSTEMS, AND METHODS, U.S. patent application
Ser. No. 13/161,183, filed Jun. 15, 2011, entitled GROUND-TRACKING
DEVICES FOR USE WITH A MAPPING LOCATOR, U.S. patent application
Ser. No. 13/766,670, filed Feb. 13, 2013, entitled OPTICAL GROUND
TRACKING LOCATOR DEVICES & METHODS, U.S. Provisional Patent
Application Ser. No. 61/679,672, filed Aug. 3, 2012, entitled
OPTICAL GROUND TRACKING APPARATUS, SYSTEMS & METHODS, U.S.
patent application Ser. No. 10/268,641, filed Oct. 9, 2002,
entitled OMNIDIRECTIONAL SONDE AND LINE LOCATOR, U.S. patent
application Ser. No. 11/077,947, filed Mar. 11, 2005, entitled
SINGLE AND MULTI-TRACE OMNIDIRECTIONAL SONDE AND LINE LOCATORS AND
TRANSMITTER USED THEREWITH, U.S. patent application Ser. No.
11/932,205, filed Oct. 31, 2007, entitled OMNIDIRECTIONAL SONDE AND
LINE LOCATOR, U.S. patent application Ser. No. 12/579,539, filed
Oct. 15, 2009, entitled SINGLE AND MULTI-TRACE OMNIDIRECTIONAL
SONDE AND LINE LOCATORS AND TRANSMITTER USED THEREWITH, U.S. patent
application Ser. No. 12/902,551, filed Oct. 12, 2010, entitled
OMNIDIRECTIONAL SONDE AND LINE LOCATOR, U.S. patent application
Ser. No. 12/916,886, filed Nov. 1, 2010, entitled SINGLE AND
MULTI-TRACE OMNIDIRECTIONAL SONDE AND LINE LOCATORS AND TRANSMITTER
USED THEREWITH, U.S. patent application Ser. No. 12/916,886, filed
Nov. 1, 2010, entitled SINGLE AND MULTI-TRACE OMNIDIRECTIONAL SONDE
AND LINE LOCATORS AND TRANSMITTER USED THEREWITH. U.S. patent
application Ser. No. 10/956,328, filed Oct. 1, 2004, entitled
MULTI-SENSOR MAPPING OMNI-DIRECTIONAL SONDE AND LINE LOCATORS AND
TRANSMITTER USED THEREWITH, U.S. patent application Ser. No.
11/970,818, filed Jan. 8, 2008, entitled MULTI-SENSOR MAPPING
OMNIDIRECTIONAL SONDE AND LINE LOCATOR, U.S. patent application
Ser. No. 12/103,971, filed Apr. 16, 2008, entitled LOCATOR AND
TRANSMITTER CALIBRATION SYSTEM, U.S. patent application Ser. No.
12/243,191, filed Oct. 1, 2008, entitled MULTI-SENSOR MAPPING
OMNIDIRECTIONAL SONDE AND LINE LOCATORS AND TRANSMITTER USED
THEREWITH, U.S. patent application Ser. No. 12/780,311, filed May
14, 2010, entitled SONDE ARRAY FOR USE WITH BURIED LINE LOCATOR,
U.S. patent application Ser. No. 12/826,427, filed Jun. 29, 21010,
entitled LOCATOR AND TRANSMITTER CALIBRATION SYSTEM, U.S. patent
application Ser. No. 13/356,408, filed Jan. 23, 2012, entitled
SONDES & METHODS FOR USE WITH BURIED LINE LOCATOR SYSTEMS, U.S.
patent application Ser. No. 10/886,856, filed Jul. 8, 2004,
entitled SONDES FOR LOCATING UNDERGROUND PIPES AND CONDUITS, U.S.
patent application Ser. No. 11/683,553, filed Mar. 8, 2007,
entitled SONDES FOR LOCATING UNDERGROUND PIPES AND CONDUITS, U.S.
Provisional Patent Application Ser. No. 61/789,074, entitled SONDE
DEVICES INCLUDING A SECTIONAL FERRITE CORE STRUCTURE, filed Mar.
15, 2013 and U.S. patent application Ser. No. 11/864,980, filed
Sep. 29, 2007, entitled SONDES FOR LOCATING UNDERGROUND PIPES AND
CONDUITS. The content of each of these applications is hereby
incorporated by reference herein in its entirety for all purposes.
Various details as described in these incorporated applications
and/or in the applications to which this application claims
priority may be combined with the disclosures herein in various
additional embodiments. For example, locators as described in the
incorporated applications may include details of implementations of
sondes and sonde arrays as described herein and/or in other
incorporated applications or priority applications. Systems
including locators, buried object transmitters, and other system
elements may include ground tracking embodiments as described
herein. Processing of sonde signals may be implemented using
antennas, signal processing circuits, processing elements, storage
elements, memory, and/or display elements or devices as described
in the priority and/or incorporated applications.
[0076] The term "exemplary" is used herein to mean "serving as an
example, instance, or illustration." Any aspect and/or embodiment
described herein as "exemplary" is not necessarily to be construed
as preferred or advantageous over other aspects and/or
embodiments.
[0077] Example Ground Tracking System Embodiments
[0078] Referring to FIG. 1, an embodiment of a ground tracking
system 100, in use, is illustrated in accordance with aspects of
the present disclosure. In one aspect, ground tracking system 100
may include a measurement device, such as a portable locator 110,
for detecting a series of electromagnetic signals 105 radiated or
emitted from a buried object 103, such as an electrical power
transmission cable, which may be disposed under the surface of the
ground 107 (such as under a street, soil or grass, concrete, or
other surface), and a ground follower assembly 120 to follow the
ground or other surfaces and provide sensed data with respect to
multiple positions and movements of the locator 110 relative to the
ground or other surfaces. Locator 110 may include one or more
antenna nodes, such as, for example, an upper antenna node 112, and
a lower antenna node 114, which may be disposed on a mast 116. In
one aspect, ground follower assembly 120 may be coupled to lower
antenna node 114 of the locator 110. In an exemplary embodiment,
the ground follower assembly 120 may be detachable such that the
ground follower assembly 120 may be readily attached or removed
from the locator 110. Although not shown in FIG. 1, ground follower
assembly may comprise a wheel assembly (e.g., wheel assembly 230 of
FIG. 2A).
[0079] In an exemplary embodiment, a separate transmitter (not
shown) may provide an inductive magnetic field output for inducing
alternating current (AC) in buried object 103, and/or current
output from a separate transmitter (not shown) may be directly
coupled to buried object 103. In some embodiments, the inducer or
dipole beacon assembly may be configured to induce current into a
buried conductor. The electromagnetic signal 105, such as
electromagnetic signals generated by a current in a buried object
103, may be detected by the locator 110. Examples of portable
locators include battery powered man portable utility locators such
as those described in incorporated U.S. Pat. Nos. 7,009,399,
7,733,077, and 7,332,091.
[0080] One or more sensor elements and associated hardware and
signal processing circuits may be used to sense relative position
and motion, and other information.
[0081] Referring to FIG. 2A, details of ground tracking system
embodiment 100 of FIG. 1 are illustrated. In an exemplary
embodiment, a wheel assembly 230 may be coupled to a lower antenna
node 114, such as, for example, a quad gradient node and/or any
round antenna node disposed at the end of a locating device. An
anchoring assembly, such as, for example, a yoke element 234 may be
used to anchor the wheel assembly 230 to a race ring assembly (not
shown in FIG. 2A), which may be disposed circumferentially at the
equator of lower antenna node 114. A stowage clip 236, which may be
disposed on mast 116, may be used to fold up the ground follower
assembly 120 for compact stowage. In an exemplary embodiment,
elements of the wheel assembly 230 may snap or lock into the
stowage clip 236.
[0082] As illustrated in FIG. 2B, a magnetic dipole beacon or
beacons may be installed within or onto the wheel assembly 230.
Such a dipole beacon may utilize, for instance, passive and/or
radio-frequency identification (RFID) technology powered by a
battery within the wheel assembly 230, yoke element 234, and/or
locator 110 (FIG. 1). Excitation coil or coils within a locator 110
(FIG. 1) or other external transmitters may be used to activate one
or more passive RFID beacons such as the passive RFID sonde 240 of
FIG. 2B. In FIG. 2B, a single passive RFID sonde 240 is positioned
toward the edge of a wheel on the wheel assembly 230. In other
embodiments, any number of beacons may be used in a number of
different positions and orientations capable of operating in one or
more different frequencies. In some embodiments, a passive RFID
device disposed in a wheel or other element such as a support
element, axle, bracket, and the like may be excited at a first
frequency and may respond at a second frequency, that may be
different than the first frequency. The received signal may be
processed through a fast fourier transform (FFT) to determine
position and/or motion.
[0083] Turning to FIG. 2C-2E, beacon and sonde assembly, such as
the beacon and sonde assembly 250, may be built into or onto a yoke
element such as the yoke element 234. As best illustrated in FIG.
2D, an assembly embodiment 250 may include a vertical dipole coil
252, a battery 254, and a series of magnetic sensors 256 which may
be in or on a housing 258. In such embodiments, the wheel assembly
may or may not include additional inducers or magnetic dipole
beacons. Magnets (not illustrated) may be secured into or onto each
wheel on the wheel assembly 230. The magnets may be positioned
along the circumference of each wheel or otherwise positioned such
that the magnetic sensors 256 may be used to sense rotations of
each wheel.
[0084] FIG. 3 illustrates details of a ground tracking system
embodiments 100 (FIGS. 1 and 2), moving across the surface of
ground 107 or other surface. In one aspect, the wheel assembly
remains in contact with ground 107. A height 303 may be determined
by finding the magnetic (B) field strength, from a source (e.g., an
inductor such as a Litz wire or a magnetic dipole sonde beacon
disposed in the wheel assembly), at each antenna node, such as,
upper antenna node 112 and lower antenna node 114. In one aspect,
the distance from the wheel assembly to the center of the antenna
node is proportional to 1/R.sup.3, where r is the distance from the
source, so:
B upper = K / R upper 3 ##EQU00001## B lower = K / R lower 3
##EQU00001.2## Therefore : R upper R lower - ( B lower B upper ) 1
/ 3 ##EQU00001.3##
[0085] The bottom length is a known fixed quantity, so:
R top = ( B bottom B top ) 1 / 3 R bottom ##EQU00002##
[0086] R.sub.Const 309 may be measured as the distance between the
center of the wheel assembly 230 and annular race axle along the
length of the yoke element 234. The distances between the upper/top
antenna node 112 and the wheel assembly 230, such as R1 305 and R2
307, may be solved geometrically. Once the distances from the upper
antenna to the wheel axle are known, such as R1 305 and R2 307, the
approximate height 303 of the lower antenna 114 from the ground 107
may be calculated geometrically.
[0087] Other sensors may be used to determine R1 305 and R2 307,
including acoustic sensors, optical sensors and/or other
sensors.
[0088] Referring to FIG. 4, an enlarged detailed rear view of
ground follower assembly 120 including a wheel assembly 230
following over uneven terrain is illustrated. In an exemplary
embodiment, wheel assembly 230 may include one or more wheels, such
as, for example, a pair of floating wheels, such as a left floating
wheel 450, a right floating wheel 460, and a fixed center wheel,
such as center wheel 470. In one aspect, floating wheels 450 and
460 may include a flexible mechanism, such as spiral spokes (not
shown in FIG. 4) to allow wheels 450, 460, and 470 to maintain
contact with the ground simultaneously. For example, over an uneven
terrain, left floating wheel 450 and right floating wheel 460 may
each elevate (float upwards) or drop (float downward) to maintain
contact with the varying surface of the ground 107, independently
from one another and center wheel 470. For example, if an operator
102 turns or pivots, each of wheels 450, 460, and 470 may rotate in
different directions relative to each other. Thus, the rotation on
the ground may be measured by how wheels 450, 460, and 470 turn
with respect to each other (like a pair of casters).
[0089] One or more magnets and/or other sensing elements (not shown
in FIG. 4), such as three-axis magnetometers and/or a single axis
Hall effect sensor, may be disposed in the wheel assembly to
generate position and/or motion signals. Various circuit elements,
such one or more compass chips (not shown) may be used to ascertain
how floating wheels 450 and 460 turn relative to the center wheel
470. For example, a compass chip may be used to count the magnetic
bumps to count the turns of left floating wheel 450 relative to
floating wheel 460. An ISM (industrial, scientific and medical)
radio or any other wireless technology may be used to transmit such
data and information corresponding to wheel rotation and positional
information. One or more compass sensors, one or more light sensors
and/or a barometer may be disposed in the wheel assembly 230.
[0090] Referring to FIG. 5A, a top view of a ground follower
assembly 120 configured with lower antenna node 114 is illustrated.
In one aspect, the ground follower assembly 120 may swivel around
lower antenna node 114 in the clockwise or counter clockwise
direction relative to a center line 507. In one aspect, an angle of
rotation, such as angle .theta. 509 about center line 507 may be
ascertained by measuring the angle of the B field lines 505, which
may be generated by an inductor, such as a Litz wire (not shown in
FIG. 5A), which may be disposed within the center wheel 470.
[0091] Turning to embodiment 550 of FIG. 5B, a locator 560 with an
omni-directional antenna node 565, may be configured to determine
the position of and/or measure the displacements of a ground
tracking assembly 570 with one or more dipole beacons 575 as the
ground tracking assembly 570 is made to rotate about a central
z-axis of the omni-directional antenna node 565. For instance, the
omni-directional antenna node 565 may be configured to measure the
magnetic field of the dipole beacons 575 in both strength and
direction. An angle .theta. 580 may be determined indicating a
rotation of the ground tracking assembly 570 about the central
z-axis of the omni-directional antenna node 565.
[0092] Referring to FIG. 6, an exploded view of the ground tracking
system embodiment 110 (FIGS. 1 and 2) illustrates details. In one
aspect, yoke element 234 may be formed of a right yoke arm 602 and
a left yoke arm 604 and mounted to an annular race assembly 640 and
wheel assembly 230.
[0093] One or more tubes, such as a pair of carbon cross tubes 608
may be disposed between right yoke arm 602 and left yoke arm 604 to
provide stabilization of the ground follower assembly 120. Tubes
608 may be secured between right yoke arm 602 and left yoke arm 604
with one or more screws, such as a pair of long screws 612, and
secured with one or more nuts, such as a pair of nuts 614. In an
exemplary embodiment, annular race assembly 640 may provide a
mechanism for 360 degree rotation of the ground follower assembly
120 around the lower antenna node 114.
[0094] A plurality of latches, such as one or more race ring
latches 634 may be used to couple race rings (not shown in FIG. 6)
of annular race assembly 640, such as, for example, upper race ring
742 and lower race ring 754 to the housing of antenna node 114 with
one or more fasteners, such as race ring latch mounting screws
632.
[0095] The ground follower assembly 120 may be stowed in an upright
configuration and locked into stowage clip 236. In an exemplary
embodiment, ground follower assembly 120 may be folded upwards at
the hinge or race axles 752 (see FIG. 7), which may be disposed on
a race yoke element 744 (see FIG. 7). Stowage clip 236 may be
formed of two halves, such as a right stowage clip half 622 and
left stowage clip half 626 mounted together on mast 116 using one
or more fasteners, such as right stowage mounting screws 624 and
left stowage mounting screws 628.
[0096] Referring to FIG. 7, an exploded view of an embodiment of an
annular race assembly 640 illustrates details of the race assembly
640. In one aspect, annular race assembly 640 may include one or
more race rings, such as for example, upper race ring 742 and lower
race ring 754, which may be fixed to the housing of antenna node
114. In assembly, a yoke race ring 744 may be disposed between
upper race ring 742 and lower race ring 754. In an exemplary
embodiment, a pair of axle elements 752 may be disposed on the
outer surface of yoke race ring 744 to provide a hinge for coupling
yoke element 234 (FIGS. 2-5) to yoke race ring 744, and for
mounting one or more race roller elements 748 to provide a
mechanism for the yoke race ring 744 to glide along upper race ring
742 and lower race ring 754. A pair of race roller elements 748 may
be secured to axles 752, and may be retained with one or more
fasteners, such as a pair of axle keeper snaps 746.
[0097] In assembly, upper race ring 742 and lower race ring 754 may
be firmly secured to the housing of lower antenna node 114 with
race ring latches 634. Yoke race ring 744 may slide freely on one
or more race rollers 748 relative to fixed race rings, for example,
upper race ring 742 and lower race ring 754.
[0098] Referring to FIG. 8, an enlarged detailed rear view of an
embodiment of wheel assembly 230 illustrates details. In one
aspect, wheel assembly may include wheel caps, such as, for
example, a left wheel cap 802 and a right wheel cap 804, disposed
on the outer surface of left floating wheel 450 and right floating
wheel 460 to provide a mechanism for anchoring the yoke 234 to the
wheel assembly. For example, left yoke arm half 604 and right yoke
arm half 602 may be coupled to left wheel cap 802 and right wheel
cap 804, respectively. In one aspect, left wheel cap 802 and a
right wheel cap 804 may be used to capture and electrically connect
a battery element to various circuit elements disposed in the wheel
assembly. Left wheel cap 802 and a right wheel cap 804 may
additionally protect the inner components from water, dirt, and
dust.
[0099] In an exemplary embodiment, wheel assembly 230 may include a
left floating wheel O-ring 852 stretched around left floating wheel
450, a right floating wheel O-ring 862 stretched around right
floating wheel 460, and center floating wheel O-ring 872 stretched
around center wheel 470, to provide traction between each wheel
450, 460, and 470, and the ground.
[0100] One or more magnets (not shown in FIG. 8) and/or other
sensing elements may be disposed in floating wheels 450 and 460 to
generate position and/or motion signals. In an exemplary
embodiment, magnets, such as North and South magnets, may be
configured in an alternating pattern and evenly spaced from one
another.
[0101] FIG. 9 is an exploded view of the wheel assembly embodiment
230 illustrating details thereof. In an exemplary embodiment, a
pair of race rollers, such as left race roller 942 and right race
roller 944, may be disposed on the outer surface of the wheel caps,
such as left wheel cap 802 and right wheel cap 804, respectively to
provide a mechanism to removably attach right and left yoke arm
halves 602 and 604 from the wheel assembly 230.
[0102] In one aspect, center wheel 470 may be formed by a left
center wheel housing half 926 and a right center wheel housing half
928, which may be mated and sealed with a sealing element, such as
an O-ring 936, and secured with one or more fasteners, such as with
left housing screws 954 and right housing screws 958. A battery
element 922, such as a C-cell battery, may be disposed in a battery
tube 924 within center wheel 470 to provide power to various
circuitry of ground tracking system 100. The battery element 922
may be seated in battery tube 924, and press against various
battery contact elements, such as disks, springs, clips or other
metallic parts, which may be electrically connected to one or more
circuit elements disposed in wheel assembly 230. Such contact
elements may be sealed or compartmentalized within wheel caps 802
and 804 with various materials, such as foam or an O-ring. For
example, a left battery contact disk 952 and a battery contact
spring 968 may be secured together and onto the inside surface of
left wheel cap 802 with a fastening element or rivet, such as a
left eyelet 932. Likewise, a right battery contact disk element 956
may be disposed on the inner surface of right wheel cap 804, and
may be secured by fastening element or rivet, such as a right
eyelet 934. In assembly, the battery element 922 snaps in firmly
between contact spring 968 and right battery contact disk element
956 to complete the circuit and provide power to various circuit
elements, which may be disposed in wheel assembly 230, such as PCB
962 and one or more sensor boards, such as a pair of magnet sensor
boards 982.
[0103] A plurality of discrete rolling elements, such as ball
bearings, may be disposed in wheel assembly 230 to reduce friction
between moving element, yoke race 744, and fixed elements, such as
upper race ring 742 and lower race ring 754. Left floating wheel
ball bearings 902 and right floating wheel ball bearings 904 may be
made of various materials, such as Delrin.RTM., Phenoxy.RTM., or
other similar polycarbonate resins or polymeric materials. In an
exemplary embodiment, a plurality of left floating wheel ball
bearings 902 may be disposed between left center wheel housing half
926 and left floating wheel 450. One or more fasteners, such as
left capture plate screws 912 may be used to secure bearings 902
against left center wheel housing half 926 through one or more
holes formed into a left capture plate 906. Likewise, a plurality
of right floating wheel ball bearings 904 may be disposed between
right center wheel housing half 928 and right floating wheel 460.
One or more fasteners, such as right capture plate screws 914 may
be used to secure bearings 904 against right center wheel housing
half 928 through one or more holes formed into a right capture
plate 908.
[0104] One or more circuit elements, such as PCB 962, and magnet
sensor boards 982, may be disposed in the wheel assembly 230, such
as for example, in the center wheel 470, for ascertaining and
processing various signals, measurements, and other information. A
coil of wire, such as a Litz wire 966, may be disposed within
center wheel 470, to provide a dipole field, such as the B field
lines 505 emitted from the center of lower antenna node 114, as
shown in FIG. 5A. Information corresponding to B field lines and
various distance measurements provide a mechanism for determining
the height of the lower antenna node 114 from the ground or other
surface.
[0105] FIG. 10 is an enlarged detailed side view of the wheel
assembly 230 of FIGS. 2-6, and 8-9. In an exemplary embodiment, a
left floating wheel housing 1002 may be mated with a right floating
wheel housing (not shown in FIG. 10), and mounted together with one
or more fasteners, such as screws 1006. In one aspect, a plurality
of spokes, such as spiral spokes 1004, may be formed in the hub of
left floating wheel housing 1002 to provide a flexible or floating
mechanism to allow floating wheels 450 and 460 to maintain contact
with the ground when rolled across uneven terrain. One or more gap
spacers 1012 may be disposed between left floating wheel housing
1002 and right floating wheel housing 1032 to capture magnets (not
shown in FIG. 10) and to center spiral spokes 1004. For example,
gap spacers 1012 may be used to prevent flexion of the spiral
spokes 1004 in the horizontal direction.
[0106] Other flexible materials may alternately be used in place of
and/or in combination with spiral spokes 1004. For example, coil
springs, compression springs, hydraulic and/or pneumatic cylinders,
and other materials used in various types of suspension systems may
be used to provide a flexible mechanism for floating wheels 450 and
460 to roll over uneven terrain and maintain contact with the
ground.
[0107] FIG. 11 is an enlarged vertical section view of the wheel
assembly 230, taken along line 11-11 of FIG. 10. In an exemplary
embodiment, one or more gap spacers 1012 may be used to retain a
plurality of magnets 1118 within floating wheels 450 and 460 (FIGS.
4, and 8-9) and maintain vertical alignment of spiral spokes 1004.
For example, gap spacers 1012 may be used to limit flexion of the
spiral spokes 1004 to the vertical direction. Magnets 1118 and gap
spacers 1012 may be distributed radially in an alternating pattern
(North-South), and evenly spaced from one another, within left
floating wheel 450 and right floating wheel 460. In assembly, the
battery element 922 snaps in firmly between contact spring 968 and
right battery contact disk element 956 to provide power to various
circuit elements, such as PCB 962 and magnet sensor boards 982
disposed in center wheel 470. Left floating wheel ball bearings 902
and right floating wheel ball bearings 904 may be disposed radially
within wheel assembly 230 and retained by left bearing capture 906
and right bearing capture 908, respectively.
[0108] FIG. 12 is an enlarged detailed side view of an embodiment
of a floating wheel of FIGS. 8-11. Spiral spokes may be formed into
the housing of each of the floating wheels 450 and 460 (not shown
in FIG. 12) in a spiral configuration to provide vertical flexion
(up or down) when the ground follower assembly 120 is rolled across
an uneven surface. Thus, the wheels 450 and 460 may essentially
float up or down, depending on the surface of the ground, and
maintain contact with the ground or surface.
[0109] FIG. 13 is an exploded view of the floating wheel 450
illustrating details thereof. In an exemplary embodiment, left
floating wheel housing 1002 and right floating wheel housing 1302
may be mated and secured with left housing screws 1006 and right
housing screws 1306. Magnets 1118 and gap spacers 1012 may be
distributed radially in an alternating pattern (North-South), and
evenly spaced from one another, within left floating wheel 450 and
right floating wheel 460 (not shown in FIG. 13). In one aspect, one
or more accelerometers 1416 (not shown in FIG. 13) may be disposed
in floating wheels, such as left floating wheel 450, and the
centripetal acceleration may provide a direct measurement of the
velocity.
[0110] FIG. 14 is a block diagram illustrating an embodiment of a
ground tracking system 1400 in accordance with aspects of the
present disclosure. Ground tracking system 1400 may correspond with
ground tracking system 100. In the exemplary embodiment, various
sensor elements may be used to detect position and/or motion about
two or more axes of motion of the ground follower assembly 120 and
generate signals corresponding to position and/or motion of the
locator 110, relative to the surface of the ground in two or more
axes or directions of motion. In one aspect, a ground tracking
system 1400 may include a processor, such as an ARM processor 1410,
which may include one or more sensor elements, such an
accelerometer, such as a 3-axis accelerometer 1416, for sensing
orientation in X, Y and Z dimensions.
[0111] In an exemplary embodiment, ground tracking system 1400 may
include one or more magnetometers, such as a first floating wheel
compass 1412 and a second floating wheel compass 1414. An ISM radio
1418 may be used to transmit data and other information. Ground
tracking system 1400 may optionally include a gyroscope, a GPS
and/or a barometer.
[0112] Turning to FIGS. 15A and 15B, current may be induced onto
the dipole beacons in various ways. Some embodiments may use direct
excitation as illustrated in the direct excitation circuit 1500 of
FIG. 15A. In other embodiments, such as illustrated in circuit
1550, a primary coil 1570 may be used to induce current into a
secondary coil within the dipole beacon.
[0113] Turning to FIGS. 16A, 16B, and 16C, any number of beacons
may be used in a number of different positions and orientations
capable of operating at one or more different frequencies in
various embodiments of rolling or moving elements including one or
more sondes and/or sonde arrays and associated power supplies,
batteries, and the like.
[0114] As illustrated in FIG. 16A, wheels, such as wheels 1610a and
1610b, of a ground tracking device wheel assembly in keeping with
aspects of the present disclosure may include multiple magnetic
dipole beacons or inductors such as the sondes 1620. On wheel 1610a
and wheel 1610b, a pair of sondes 1620 may be positioned along the
same diameter of their respective wheel such that each sonde 1620
of the sonde 1620 pair may have similarly oriented polarities. In
such embodiments, such as that illustrated in FIG. 16B, each wheel
of the wheels 1610a and 1610b may have differently oriented
diameter to which each sonde 1620 pairing may be secured such that
the combined field generated by each pair of sondes 1620 may be
staggered. The combined field from each pair of sondes 1620 may
appear as one field to the antenna node of a locator device.
[0115] In some embodiments the dipole beacons may be secured about
different locations along a wheel oriented in directions other than
aligned with the wheel's axis or radius/diameter. For instance, in
FIG. 16B, a wheel 1625 may contain four dipole beacons such as
sonde 1630a, 1630b, 1630c, and 1630d. In such embodiments, sonde
1630a and sonde 1630b may be oriented parallel to one another and
perpendicular to the radius of wheel 1625 near the outer
circumference of wheel 1625. Similarly, sonde 1630c and sonde 1630d
may be oriented parallel to one another and orthogonal to the
radius of wheel 1625 near the outer circumference of wheel 1625.
The parallel set of sondes 1630a/1630b may be oriented orthogonally
to the other parallel set of sondes 1630c/1630d. In some
embodiments, each parallel sonde pairing, such as sondes 1630a/b
and sondes 1630c/d, may have dipoles with similarly oriented
polarities. In other embodiments, each parallel sonde pairing, such
as sondes 1630a/b and sondes 1630c/d, may have dipoles with
oppositely oriented polarities. In some embodiments, each parallel
sonde pairing, such as sondes 1630a/b and sondes 1630c/d, may be
configured to generate the same frequency, different frequencies,
or a variety of frequencies that may be time multiplexed as
described in, for example, co-assigned U.S. Patent Application Ser.
No. 61/779,830, entitled QUAD-GRADIENT COILS FOR USE IN LOCATING
SYSTEMS, filed Mar. 14, 2013, U.S. patent application Ser. No.
13/676,989, entitled QUAD-GRADIENT COILS FOR USE IN LOCATING
SYSTEMS, filed Nov. 14, 2012, and U.S. Patent Application Ser. No.
61/781,889, entitled OMNI-UDUCER TRANSMITTING DEVICES AND METHODS,
filed Mar. 14, 2013. The content of each of these applications is
hereby incorporated by reference herein in its entirety for all
purposes.
[0116] Turning to FIG. 16C, wheels, such as wheel 1635, of a ground
tracking device in keeping with aspects of the present disclosure
may contain magnetic dipole beacons such as sondes 1640. The sondes
1640 may be wired as illustrated to produce magnetic fields with
similarly oriented polarities from each sonde 1640.
[0117] Turning to FIGS. 17A, 17B, and 17C, a locator device may be
fitted or coupled to a ground tracking device which may be secured
to the locator device in ways other than by attaching to an antenna
node. For instance, the ground tracking device 1720 may secure to
the mast of a locator 1710. In such embodiments, the ground
tracking device 1720 may be configured to rotate about the vertical
axis of the mast. The ground tracking device 1720 may be further
configured to pivot or swivel upward and downward to compensate for
rolling about uneven terrain of the ground or operating surface as
well as possible stowage of the device. As illustrated in FIGS. 17B
and 17C, a tripod accessory, such as tripod attachment 1730, may be
used on a locator device in conjunction with a ground tracking
device such as the ground tracking device 1720. As illustrated in
FIG. 17C, other embodiments of ground tracking devices, such as the
ground tracking device 1740, may be used with a tripod accessory
such as the tripod attachment 1730.
[0118] Turning to FIG. 18, an antenna node of a locator 1810 may be
fitted or coupled to a dragging dipole beacon such as shown in
embodiment 1820. In the embodiment 1820, a yolk assembly 1830 may
secure about an antenna node while a connected arm 1840 with a
sonde 1850 positioned about its end may be configured to drag along
the ground or operating surface. The arm 1840 may be configured to
rotate about the vertical axis of the locator 1810 mast. The arm
1840 may further be pliant allowing it to move up and down along
the operating surface as well as twist.
[0119] Turning to FIGS. 19A-19C, an antenna node of a locator 1910
may be fitted with a dipole beacon embodiment 1920. In the
embodiment 1920, a yolk assembly 1930 may secure about an antenna
node while a connected arm 1940 with a sonde wheel assembly 1950
positioned about its end may be configured to be wheeled along the
ground or operating surface. The arm 1940 may be configured to
rotate about the vertical axis of the locator 1910 mast. The arm
1940 may further be pliant allowing it to move up and down along
the operating surface as well as twist. As illustrated in FIG. 19C
the sonde wheel assembly 1950 may include one or more vertical
dipole beacons in a sonde array such as the vertical sondes 1952,
secured to or within each of the wheels 1954, a battery 1956, and a
horizontal sonde 1958 incased within a housing 1960. The wheels
1954 may be configured to rotate independently of each other. Some
embodiments may use two wheels in a wheel assembly, wherein each
wheel may include one or more sondes. In some embodiments, each
wheel may include a sonde array of two or more sondes, which may be
oriented in different positions and/or axis dimensions on the
wheel, such as in two or more orthogonal axes. Some embodiments may
use two wheels in a wheel assembly, while others may use three or
more wheels in a wheel assembly. The wheels in assemblies with two
or more wheels may be further configured to be axially displaced
relative to each other. This may be done to allow each wheel to
track a surface contour, such as shown in FIG. 4, while sending
signals from one or more sondes in each of the wheels. These sonde
signals may be received by a corresponding locator and used to
generate additional information associated with the ground surface,
such as contour information. On level surfaces, information may be
determined in the locator or other device based on signals provided
from sondes in multiple wheels when the wheel assembly is rotated
about a vertical or other axis of the locator, such as when the
locator is swept around in a circle or other arcs about a point or
line.
[0120] Turning to FIGS. 20A-20E, a locator 2010 with lower antenna
node 2020 may be configured to allow an omni-inducer and ground
tracking embodiment 2030 to secure to the lower antenna node 2020.
The ground tracking embodiment 2030 may snap on to secure to the
lower antenna node 2020. The ground tracking embodiment 2030 may
have an arm 2040 which may be pliant allowing it to move up and
down along the operating surface as well as twist. The arm 2040 may
be configured to rotate about the vertical axis of the locator 2010
mast. An omni-directional inducer wheel 2050 may secure about the
end of the arm 2040 and be configured to rotate along the ground or
operating surface when in use. The ground tracking embodiment 2030
may be stowed out of the way when not in use through the stowage
clip 2060 as illustrated in FIG. 20C.
[0121] As illustrated in FIG. 20D, the omni-inducer wheel 2050 may
include a housing 2062 that may house a series of antenna coils
2065 in an omni-directional antenna configuration as described in,
for example, co-assigned U.S. Pat. No. 8,035,390, entitled
OMNIDIRECTIONAL SONDE AND LINE LOCATOR, issued Oct. 9, 2002, the
content of which is incorporated by reference herein. An axle 2070
may pass through the center of the omni-inducer wheel 2050 and
secure to the arm 2040 in a manner allowing the omni-inducer wheel
2050 to rotate along the ground or operating surface when in use.
The device may further include enabling circuitry and a power
source, such as a battery. As illustrated in FIG. 20E, the
omni-inducer wheel 2050 of the omni-inducer and ground tracking
embodiment 2010 may be further configured to induce currents onto
conductors, such as buried conductive pipes or cables, such as the
line 2080, in one or more directions. In such applications where a
transmitter may be needed to locate a buried utility, such an
embodiment may be used instead to induce currents onto the
utilities/conductors. Example teachings of inducing current in an
underground utility or other conductors may be found, for example,
in co-assigned U.S. Patent Application Ser. No. 61/781,889,
entitled OMNI-INDUCER TRANSMITTING DEVICES AND METHODS, filed Mar.
14, 2013 the content of which is hereby incorporated by reference
herein. The omni-inducer and ground tracking embodiment 2010 may
further be configured to sense and measure displacements of the
omni-inducer wheel 2050 as described previously herein.
[0122] Turning to FIG. 21, a paired omni-inducer and ground
tracking embodiment 2100 may be similar to the omni-inducer and
ground tracking embodiment 2030 of FIG. 20 except with multiple
omni-directional inducer wheels 2120 similar to the
omni-directional inducer wheel 2050 of FIG. 20. The embodiment 2100
may have an arm 2110 that may be configured to rotate about the
vertical axis of a locator mast. Two omni-directional inducer
wheels 2120 may secure about the end of the arm 2110 and be
configured to rotate along the ground or operating surface when in
use. The arm 2110 may be pliant allowing it to move up and down
along the operating surface as well as twist. The arm 2110 may
further snap onto the bottom of a locator device through a snap on
feature 2130. The omni-directional inducer wheels 2120 may, for
instance, be powered by internal batteries, such as internal
rechargeable batteries or replaceable batteries, which may be
accessed via a door or other panel or cover. In some such
embodiments, an inductive clamp or charger may be used to recharge
internal batteries, such as a commercially available 18650 battery.
In other embodiments, the omni-directional inducer wheels 2120 may
utilize standard sized disposable batteries. The embodiment 2100
may be stowed out of the way when not in use through the use of a
stow hook 2140.
[0123] The ground tracking embodiments in keeping with the present
disclosure as described in the various preceding paragraphs need
not be connected to a locator device, but may be used in
conjunction with other devices or systems where tracking of
movement, position, or location may be needed or desirable. In
addition, in locators or other devices, motion, position,
orientation, or tracking information as may be generated from sonde
signals may be associated with or combined with other location or
positional information, such as from inertial sensors,
accelerometers, compass sensors, GPS modules, or other satellite or
ground-based positioning signals or systems from networks such as
cellular networks and the like. These additional signals may be
used to refine location or position information in conjunction with
the information provided from sonde-based signaling or to
cross-check or calibrate positional information from multiple
information sources in various embodiments.
[0124] Turning to FIG. 22, a ground tracking embodiment in keeping
with aspects of the present disclosure, such as the ground tracking
embodiment 2200, may be configured to attach to/or be carried by a
user 2210. In such embodiments, the user 2210 may hold and operate
a locator 2220 at the same time.
[0125] Turning to FIG. 23, a ground tracking embodiment in keeping
with aspects of the present disclosure, such as the ground tracking
embodiment 2300, may be configured to attach to a vehicle 2310. In
such cases, one or more additional instrumentation devices,
sensors, and/or devices may be used as well. Examples of such
instruments, sensors, and other devices may be found in, for
example, the disclosure of co-assigned U.S. Patent Application Ser.
No. 61/781,889, entitled OMNI-INDUCER TRANSMITTING DEVICES AND
METHODS, filed Mar. 14, 2013, the content of which is incorporated
by reference herein. In such embodiments, a user 2320 with a
locator 2330 may follow after, lead, or walk beside the vehicle
2310 during use.
[0126] In some embodiments, accelerometers or other motion sensors
may be included in wheel assemblies or incorporated in or coupled
to sondes or sonde arrays in conjunction with a circuit for
awakening or powering up a ground tracking device in keeping with
the present disclosure. For example, such sensors may be used to
wake the device from a sleeping state or low powered or powered
down state.
[0127] In various embodiments, the sensed motion signals may be
processed in whole, or in part by the measurement circuit, with
processed data or information sent to the locator 110. Sensed
motion signals may optionally be processed in the locator 110. In
one aspect, sensed motion signals may be used to calculate and map
position, motion, location, orientation, and/or terrain data or
information associated with movements of locator 110 by operator
102.
[0128] Signals provided from the ground tracking system 1400 may be
combined or processed in combination with additional signals
provided from the locator 110 to generate the position and/or
movement data as well as to generate mapping data for the locating
or tracing operation. For example, accelerometer or other motion
sensing devices in a locator may be combined with motion signals
from the ground follower assembly 120 to distinguish relative
movements associated with the locator from movements generated by
sensors in the ground tracking device. This can be used to generate
more complete mapping data reflecting position and movements of the
ground tracking system 1400. The data may be stored in the ground
follower device 120 or locator 110 or other instrument for
subsequent download and/or processing.
[0129] In an exemplary embodiment, the sensors may comprise
magnetic sensors and associated permanent magnets to generate
position and/or motion signals. However, in some embodiments,
optical encoders, potentiometers, gyroscopic devices, compass
devices, and/or other sensor elements and associated hardware and
signal processing circuits may be used to sense relative position
and motion, and other information.
[0130] Various example embodiments have been described previously
herein to provide ground tracking devices that may be coupled to a
locator or other measurement device. The ground tracking devices
may be configured with a ground follower assembly, which may use an
element such as one or more wheels, a sphere, or other mechanisms
to follow the ground or other surfaces and provide sensed motion
signals in multiple axes or dimensions. The motion signals may be
processed in a processing circuit of the ground follower assembly
to filter, correlate, generate motion and/or position data, and/or
integrate the motion signals with other sensor data or information.
The motion signals may be provided, either as raw signals or
processed signals or data to the attached measurement device for
further processing and/or data storage. Other combinations of the
various aspects, elements, components, features, and/or functions
described previously herein may be combined in various
configurations.
[0131] In addition, details regarding additional aspects, elements,
components, features, functions, apparatus, and/or methods which
may be used in conjunction with the embodiments described
previously herein in various implementations are described in the
related applications of the assignee of the instant
application.
[0132] In some configurations, the devices, elements, mechanisms,
or apparatus may include means for performing various functions as
described herein, such as are illustrated in the appended drawing
figures. The aforementioned means may be, for example, mechanical
elements such as wheels or other ground follower elements, sensor
elements, processor or processors and associated memory in which
embodiments reside, such as in processing elements, on circuit
boards or substrates, or in other electronic configurations
performing the functions recited by the aforementioned means. The
aforementioned means may include a non-transitory storage medium
including instructions for use by a processor to implement, in
whole or in part, the various sensing and measurement functions
described previously herein. In another aspect, the aforementioned
means may be a module or apparatus configured to perform the
functions recited by the aforementioned means.
[0133] In one or more exemplary embodiments, the various data
collection, measurement, storage and signal processing functions,
methods and processes described herein and/or in the related
applications may be implemented in hardware, software, firmware, or
any combination thereof. If implemented in software, the functions
may be stored on or encoded as one or more instructions or code on
a computer-readable medium. Computer-readable media includes
computer storage media. Storage media may be any available media
that can be accessed by a computer. By way of example, and not
limitation, such computer-readable media can include RAM, ROM,
EEPROM, CD-ROM or other optical disk storage, magnetic disk storage
or other magnetic storage devices, or any other medium that can be
used to carry or store desired program code in the form of
instructions or data structures and that can be accessed by a
computer. Disk and disc, as used herein, includes compact disc
(CD), laser disc, optical disc, digital versatile disc (DVD),
floppy disk and blu-ray disc where disks usually reproduce data
magnetically, while discs reproduce data optically with lasers.
Combinations of the above should also be included within the scope
of computer-readable media.
[0134] It is understood that the specific order or hierarchy of
steps or stages in the processes and methods disclosed are examples
of exemplary approaches. Based upon design preferences, it is
understood that the specific order or hierarchy of steps in the
processes may be rearranged while remaining within the scope of the
present disclosure. Any accompanying process or method claims
present elements of the various steps in a sample order, however,
this is not meant to be limiting unless specifically noted.
[0135] Those of skill in the art would understand that information
and signals may be represented using any of a variety of different
technologies and techniques. For example, data, instructions,
commands, information, signals, bits, symbols, and chips that may
be referenced throughout the above description may be represented
by voltages, currents, electromagnetic waves, magnetic fields or
particles, optical fields or particles, or any combination
thereof.
[0136] Those of skill would further appreciate that the various
illustrative logical blocks, modules, circuits, and algorithm steps
described in connection with the embodiments disclosed herein may
be implemented as electronic hardware, computer software, or
combinations of both. To clearly illustrate this interchangeability
of hardware and software, various illustrative components, blocks,
modules, circuits, and steps have been described above generally in
terms of their functionality. Whether such functionality is
implemented as hardware or software depends upon the particular
application and design constraints imposed on the overall system.
Skilled artisans may implement the described functionality in
varying ways for each particular application, but such
implementation decisions should not be interpreted as causing a
departure from the scope of the disclosure. In some embodiments
mechanical elements and functions, such as ground follower
assemblies, yoke assemblies, or other mechanical elements may be
replaced, in whole or in part, by other elements, such as acoustic
or optical elements. For example, in some embodiments, some or all
of the mechanical elements of a ground follower assembly as
described previously herein may include acoustic and/or optical
ground movement detection elements in place of or in addition to
mechanical elements such as wheels and yokes.
[0137] The various illustrative logical blocks, modules, and
circuits described in connection with the embodiments disclosed
herein may be implemented or performed in a processing element or
other circuit with a general purpose processor, special purpose
processor, a digital signal processor (DSP), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA) or other programmable logic device, discrete gate or
transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A
general purpose processor may be a microprocessor, but in the
alternative, the processor may be any conventional processor,
controller, microcontroller, or state machine. A processor may also
be implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration. In some implementations,
processors may be processors, such as communication processors,
specifically designed for implementing functionality in
communication devices or other mobile or portable devices.
[0138] The steps or stages of a method, process or algorithm
described in connection with the embodiments disclosed herein may
be embodied directly in hardware, in a software module executed by
a processor, or in a combination of the two. A software module may
reside in RAM memory, flash memory, ROM memory, EPROM memory,
EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or
any other form of storage medium known in the art. An exemplary
storage medium is coupled to the processor such that the processor
can read information from, and write information to, the storage
medium. In the alternative, the storage medium may be integral to
the processor. The processor and the storage medium may reside in
an ASIC. The ASIC may reside in a user terminal. In the
alternative, the processor and the storage medium may reside as
discrete components in a user terminal.
[0139] The scope of the present invention is not intended to be
limited to the aspects shown and described previously herein, but
should be accorded the full scope consistent with the language of
the claims, wherein reference to an element in the singular is not
intended to mean "one and only one" unless specifically so stated,
but rather "one or more". Unless specifically stated otherwise, the
term "some" refers to one or more. A phrase referring to "at least
one of" a list of items refers to any combination of those items,
including single members. As an example, "at least one of: a, b, or
c" is intended to cover: a; b; c; a and b; a and c; b and c; and a,
b and c.
[0140] The previous description of the disclosed aspects is
provided to enable any person skilled in the art to make or use the
present invention. Various modifications to these aspects will be
readily apparent to those skilled in the art, and the generic
principles defined herein may be applied to other aspects without
departing from the spirit or scope of the disclosure. Thus, the
disclosure is not intended to be limited to the aspects shown
herein but is to be accorded the widest scope consistent with the
principles and novel features disclosed herein. It is intended that
the following claims and their equivalents define the scope of the
invention.
* * * * *