U.S. patent application number 14/472826 was filed with the patent office on 2015-03-05 for shearer anti-collision.
The applicant listed for this patent is Joy MM Delaware, Inc.. Invention is credited to Alastair J. Paterson.
Application Number | 20150061350 14/472826 |
Document ID | / |
Family ID | 52582176 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150061350 |
Kind Code |
A1 |
Paterson; Alastair J. |
March 5, 2015 |
SHEARER ANTI-COLLISION
Abstract
Systems and methods for operating a mining machine. One system
includes a roof support system, a radar device, and at least one
controller. The roof support system incorporates an anti-stealth
device, and the radar device is configured to transmit a plurality
of radio waves toward the roof support system and detect a
plurality of reflections of the plurality of radio waves. The at
least one controller is configured to obtain reflection data from
the radar device representing timing information regarding the
plurality of radio waves and the plurality of reflections,
determine a position of the roof support system based on the
reflection data, and perform at least one automatic action when the
identified position of the roof support system satisfies a
threshold.
Inventors: |
Paterson; Alastair J.;
(Wollongong, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Joy MM Delaware, Inc. |
Wilmington |
DE |
US |
|
|
Family ID: |
52582176 |
Appl. No.: |
14/472826 |
Filed: |
August 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61871576 |
Aug 29, 2013 |
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61871581 |
Aug 29, 2013 |
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61871583 |
Aug 29, 2013 |
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61871586 |
Aug 29, 2013 |
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Current U.S.
Class: |
299/1.4 |
Current CPC
Class: |
E21F 17/18 20130101;
E21C 35/24 20130101; E21C 35/12 20130101; E21C 25/06 20130101; E21C
35/08 20130101; E21C 41/16 20130101 |
Class at
Publication: |
299/1.4 |
International
Class: |
E21C 35/24 20060101
E21C035/24; E21F 17/18 20060101 E21F017/18 |
Claims
1. A system for operating a mining machine, the system comprising:
a roof support system incorporating an anti-stealth device; a radar
device configured to transmit a plurality of radio waves toward the
roof support system and detect a plurality of reflections of the
plurality of radio waves; and at least one controller configured to
obtain reflection data from the radar device representing timing
information regarding the plurality of radio waves and the
plurality of reflections, determine a position of the roof support
system based on the reflection data, and perform at least one
automatic action when the identified position of the roof support
system satisfies a threshold.
2. The system of claim 1, wherein the anti-stealth device includes
a corner cube reflector.
3. The system of claim 1, wherein the anti-stealth device is
incorporated into a canopy of the roof support system.
4. The system of claim 1, wherein the anti-stealth device is
incorporated into a leg of the roof support system.
5. The system of claim 1, wherein the anti-stealth device is
incorporated into a sprag of the roof support system.
6. The system of claim 1, wherein the radar device is mounted on a
surface of a miner.
7. The system of claim 1, wherein the radar device is mounted on a
device configured to travel along a conveyor system separate from a
miner.
8. The system of claim 1, wherein at least one controller is
further configured to filter the reflection data to identify at
least one of the plurality of reflections originating from an
object located more than approximately 6 meters from the radar
device and less than approximately 10 meters from the radar
device.
9. The system of claim 1, wherein the at least one controller is
further configured to filter the reflection data to identify at
least one of the plurality of reflections having an angle within a
predetermined range of angle.
10. The system of claim 1, wherein the at least one controller is
further configured to filter the reflection data to identify at
least one of the plurality of reflections having a signal strength
greater than a predetermined threshold.
11. The system of claim 1, wherein the at least one controller is
further configured to obtain information from an inertial
navigation sensor associated with a miner and determine the
position of the roof support system based on the reflection data
and the information from the inertial navigation sensor.
12. The system of claim 1, wherein the anti-stealth device is
formed into a structure of the roof support system.
13. A method of operating mining equipment comprising: transmitting
a radio wave in a direction of travel of a miner; receiving a
reflection of the radio wave from a corner cube reflector
positioned on a roof support system; determining, with at least one
controller, a position of the corner cube reflector based on the
reflection of the radio wave; modifying operation of at least one
selected from the group comprising the miner and the roof support
system based on the position.
14. The method of claim 13, further comprising filtering the
reflection of the radio wave to determine if the reflection
originated from an object located more than approximately 6 meters
from the miner and less than approximately 10 meters from the
miner.
15. The method of claim 13, further comprising filtering the
reflection of the radio wave to determine if the reflection has an
angle within a predetermined range of angle.
16. The method of claim 13, further comprising filtering the
reflection of the radio wave to determine if the reflection has a
signal strength greater than a predetermined threshold.
17. The method of claim 13, further comprising obtaining
information from an inertial navigation sensor associated with a
miner, wherein modifying the operation includes modifying operation
of at least one selected from the group comprising the miner and
the roof support system based on the position and the information
obtained from the inertial navigation sensor.
18. The method of claim 13, further comprising transmitting a
second radio wave at the miner, receiving a reflection of the
second radio wave from the miner, and determining a position of the
miner based on the reflection of the second radio wave, wherein
modifying the operation includes modifying operation of at least
one selected from the group comprising the miner and the roof
support system based on the position of the corner cube reflector
and the position of the miner.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Nos. 61/871,576, 61/871,581, 61/871,583, and
61/871,586, each filed Aug. 29, 2013. The entire content of each
provisional application is hereby incorporated by reference.
BACKGROUND
[0002] Embodiments of the invention relate to methods and systems
for detecting objects around mining equipment, such as a longwall
shearer.
SUMMARY
[0003] Collisions between mining equipment can cause costly damage
to the mining equipment. Accordingly, embodiments of the invention
provide systems and methods for detecting objects located around
mining equipment, such as a longwall shearer. The detected objects
can include a roof support system. For example, a non-contacting
distance sensor, such as a radar sensor, can be used to detect the
distance between the longwall shearer and at least one portion of a
roof support system, such as a canopy, a leg, and/or a sprag. One
or more automatic actions can be performed depending on the
detected distance (e.g., to prevent or mitigate a collision).
[0004] In particular, one embodiment of the invention provides a
system for operating a mining machine. The system includes a roof
support system, a radar device, and at least one controller. The
roof support system incorporates an anti-stealth device. The radar
device is configured to transmit a plurality of radio waves toward
the roof support system and detect a plurality of reflections of
the plurality of radio waves. The at least one controller is
configured to obtain reflection data from the radar device
representing timing information regarding the plurality of radio
waves and the plurality of reflections, determine a position of the
roof support system based on the reflection data, and perform at
least one automatic action when the identified position of the roof
support system satisfies a threshold.
[0005] Another embodiment of the invention provides a method of
operating mining equipment. The method includes transmitting a
radio wave in a direction of travel of a miner, receiving a
reflection of the radio wave from a corner cube reflector
positioned on a roof support system, and determining, with at least
one controller, a position of the corner cube reflector based on
the reflection of the radio wave. The method also includes
modifying operation of at least one selected from the group
comprising the miner and the roof support system based on the
position.
[0006] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 schematically illustrates mining equipment.
[0008] FIG. 2 schematically illustrates mining equipment.
[0009] FIG. 3 schematically illustrates a controller for the mining
equipment of FIGS. 1 and 2.
[0010] FIG. 4 is a flowchart illustrating a method performed by the
controller of FIG. 3.
[0011] FIG. 5 graphically illustrates a region-of-interest filter
applied by the controller of FIG. 3.
[0012] FIGS. 6A-6B illustrate undulation and bends in a conveyor
system.
[0013] FIGS. 7A-7B illustrate a radar device mountable on mining
equipment according to one embodiment of the invention.
[0014] FIGS. 8A-8C illustrate the radar device of FIGS. 7A-7B
mounted on a longwall shearer according to one embodiment of the
invention.
[0015] FIG. 9 illustrates an anti-stealth device.
[0016] FIG. 10 schematically illustrates a corner cube
reflector.
[0017] FIG. 11 illustrates an anti-stealth device attached to a
roof support system.
DETAILED DESCRIPTION
[0018] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the accompanying drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways. Also, the methods, operations, and sequences
described herein can be performed in various orders. Therefore,
unless otherwise indicated herein, no required order is to be
implied from the order in which elements, steps, or limitations are
presented in the detailed description or claims of the present
application. Also unless otherwise indicated herein, the method and
process steps described herein can be combined into fewer steps or
separated into additional steps.
[0019] In addition, it is to be understood that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting. The use of "including,"
"comprising" or "having" and variations thereof herein is meant to
encompass the items listed thereafter and equivalents thereof as
well as additional items. The terms "mounted," "connected" and
"coupled" are used broadly and encompass both direct and indirect
mounting, connecting and coupling. Further, "connected" and
"coupled" are not restricted to physical or mechanical connections
or couplings, and can include electrical connections or couplings,
whether direct or indirect. Also, electronic communications and
notifications may be performed using any known means including
direct connections, wireless connections, etc.
[0020] It should also be noted that a plurality of hardware and
software based devices, as well as a plurality of different
structural components may be used to implement the invention. In
addition, it should be understood that embodiments of the invention
may include hardware, software, and electronic components or
modules that, for purposes of discussion, may be illustrated and
described as if the majority of the components were implemented
solely in hardware. However, one of ordinary skill in the art, and
based on a reading of this detailed description, would recognize
that, in at least one embodiment, the electronic based aspects of
the invention may be implemented in software (e.g., stored on
non-transitory computer-readable medium) executable by one or more
processors. As such, it should be noted that a plurality of
hardware and software based devices, as well as a plurality of
different structural components may be utilized to implement the
invention. For example, "controllers" described in the
specification can include one or more processors, one or more
non-transitory computer-readable medium modules, one or more
input/output interfaces, and various connections (e.g., a system
bus) connecting the components.
[0021] Longwall mining equipment comprises of a number of
individual structures that are connected together and/or move
relative to each other in sequence. In particular, as illustrated
in FIG. 1, the equipment includes a longwall shearer 10 that cuts
material, such as coal, from a cutting face 12. The longwall
shearer 10 can include a mobile cutting machine that includes at
least two cutter drums (an upper drum 11a and a lower drum
11b).
[0022] The shearer 10 is mounted on and moves along a conveyor
system 14. Material cut by the shearer 10 is also loaded onto the
conveyor system 14. The conveyor system 14 can include an armored
flexible conveyor that has a length approximately equal to the
width of the cutting face 12. The conveyor can include a series of
steel pans that are able to move relative to each other by flexing.
Cut material (e.g., coal) is conveyed on the conveyor by steel bars
arranged at approximately 90.degree. to the length of the conveyor,
which are moved by a pair of endless chains.
[0023] In some embodiments, the conveyor system 14 moves cut
material away from the shearer 10 to a delivery point at the end of
the conveyor system 14. At this point, conveyed material is
transferred to a beam stage loader 15 located in a pre-driven
roadway (i.e., a maingate roadway opposite a tailgate roadway).
[0024] A powered roof support system 17 is also used with the
shearer 10. The roof support system 17 includes a plurality of roof
structures or supports 18 positioned side-by-side. Individual roof
supports 18 can be advanced (e.g., after the shearer 10 passes) to
support a roof above the cutting face 12. For example, in some
embodiments, each roof support 18 includes a steel base 18a. Two or
more vertical hydraulic rams 18b (sometimes referred to as "legs")
extend from the steel base 18a and support a canopy 18c (see FIG.
2). The canopy 18c can be manufactured from steel and is designed
to be positioned parallel to and in contact with the roof. A
controller can be used to manually and/or automatically move each
roof support structure 18 (i.e., each canopy 18c using the
hydraulic rams 18b). In some embodiments, each roof support
structure can be retracted (i.e., not advanced), partially
advanced, or fully advanced.
[0025] For example, as the shearer 10 moves along the cutting face
12 removing material, a roof is exposed and needs to be supported
by advancing each roof support 18 in sequence (e.g., sequentially
following a direction of travel of the shearer 10). Prior to
advancing, the canopy 18c of a roof support 18 extends to within
approximately 400 millimeters of the upper drum 11a of the shearer
10, which is typically approximately 1,000 millimeters wide. To
support newly exposed roof, each roof support 18 can be advanced by
approximately 1,000 millimeters, which means that the canopy 18c of
an advanced roof support 18 is approximately 700 millimeters into
the path of the upper drum 11a. When a roof support 18 is advanced
in sequence, the upper drum 11a has already passed the roof support
18, and, prior to the next pass of the shearer 10, the conveyor
system 14 is pushed forward (e.g., by approximately 1,000 to
millimeters) to regain an original clearance for the upper drum 11a
from the advanced support 18 (e.g., approximately 400 millimeters).
Therefore, when advanced in sequence, roof supports 18 do not
generally pose a collision risk for the shearer 10.
[0026] However, under certain conditions, one or more roof supports
18 are operated out of sequence (e.g. to provide additional support
for an unstable roof). In this context "out of sequence" can mean
that a roof supports 18 are advanced (e.g., partially-advanced or
fully-advanced) out of order as compared to a normal or routine
sequence (e.g., sequentially). Accordingly, in some situations, a
roof support 18 is advanced before the shearer 10 passes and the
"out of sequence" roof support 18 can be a collision hazard for the
shearer 10 (e.g., the upper drum 11a).
[0027] Also, there are circumstances where the clearance distance
between an un-advanced roof support 18 and the shearer 10 is less
than a minimum distance (e.g., approximately 400 millimeters). For
example, there can be steps in the floor of the mine. When the
conveyor system 14 is applied to these steps, the "pitch angle" of
the conveyor system 14 is changed. Also, because the shearer 10
travels along the conveyor system 14, the pitch angle of the
conveyor system 14 is transferred to the shearer 10. Accordingly,
the pitch angle of the conveyor system 14 can change the
orientation of the shearer 10, which can create collision risks for
the shearer 10. In particular, creation of a positive pitch angle
in the conveyor system 14 can cause the shearer 10 to tip back
toward the roof support system 17 as the shearer 10 traverses the
cutting face 12. For example, because a height of a coal face (as
usually determined by the thickness of the coal seam) can be up to
approximately 6,000 millimeters, a pitch angle of approximately
4.degree. or more can eliminate the minimum clearance distance
between the shearer 10 and the roof support system 17 and,
consequently, create collision risks.
[0028] Similarly, if the roof support system 17 fails or
malfunctions (e.g., a hydraulic circuit fault occurs), canopies 18c
of one or more roof supports 18 may be positioned lower than the
roof, which creates a situation where the shearer 10 may collide
with the supports 18. Also, if the shearer 10 is not controlled
properly when creating the roof, the canopies 18c of the supports
18, once advanced, may have a reduced clearance with respect to the
shearer 10. Also, in some embodiments, the powered roof support
system 17 includes one or more sprags 19. Sprags 19 extend from the
face side of the roof supports 18 (i.e., the canopies 18c) toward
the cutting face 12 under circumstances where additional support
needs to be provided (e.g., where the coal seam is thick and slabs
of coal may breakaway and fall over like a wall towards the
conveyor system 14 and a walkway 22 (see FIG. 2) between the
conveyor system 14 and the roof support system 17). For example, in
some embodiments, sprags 19 are deployed when the thickness of
material (e.g., coal) being mined exceeds approximately 3.5 meters.
Sprags 19 can also be used during maintenance activities (e.g., to
provide protection to individuals carrying out maintenance
activities on the equipment). The sprags 19 can be deployed by
small rams, which if faulty or deployed at the wrong time, can
position a sprag in a position where the shearer 10 may collide
with the sprag 19.
[0029] Accordingly, in some embodiments, a shearer automation
system (e.g., installed on the shearer 10) can include an
autonomous anti-collision subsystem that uses radar ("Radio
Detection And Ranging"). Radar technology works on the basis of
detecting the reflection of a radio wave, signal, or beam generated
by a radar device from structures located around the radar device.
A radar device can include a transmitter configured to generate a
radio wave and a sensor configured to detect a radio wave. As
described in more detail below, the time between transmitting the
wave and detecting a reflection of the wave can be used to
determine the distance between the radar device and the object
reflecting the wave.
[0030] Accordingly, the anti-collision subsystem can include a
controller configured to receive timing information relating to
radio wave transmissions and detections collected by the radar
device and determine potential collisions risks. Collisions risks
for the shearer 10 can include, but are not limited to, a canopy
18c of a roof support 18 (e.g., a low canopy 18c as compared to
other canopies 18c), legs 18b of the roof support system 17 (e.g.,
legs 18b encroaching on the walkway 22 provided between the
conveyor system 14 and the roof support system 17), and sprags
19.
[0031] For example, FIG. 3 schematically illustrates a controller
28 included in the anti-collision subsystem. As illustrated in FIG.
3, the controller 28 includes a processing unit 30 (e.g., a
microprocessor, application specific integrated circuit, etc.),
non-transitory computer-readable media 32, and an input/output
interface 34. The computer-readable media 32 can include random
access memory ("RAM") and/or read-only memory ("ROM"). The
input/output interface 34 transmits and receives information from
devices external to the controller 28, such as a radar device 36
(e.g., over one or more wired and/or wireless connections). The
controller 28 can also use the input/output interface 34 to
communicate with other controllers, such as a roof support
controller, a shearer controller, etc.
[0032] The processing unit 30 receives information (e.g., from the
media 32 and/or the input/output interface 34) and processes the
information by executing one or more instructions or modules. The
instructions or modules are stored in the computer-readable media
32. The processing unit 30 also stores information (e.g.,
information received through the input/output interface 34 and/or
information generated by instructions or modules executed by the
processing unit 30) to the media 32. It should be understood that
although only a single processing unit, input/output interface, and
computer-readable media module are illustrated in FIG. 3, the
controller 28 can include multiple processing units, memory
modules, and/or input/output interfaces.
[0033] The instructions stored in the computer-readable media 32
provide particular functionality when executed by the processing
unit 30. In general, the instructions, when executed by the
processing unit 30, identify potential collision risks between
mining equipment and perform one or more actions to mitigate or
prevent such collisions. For example, the controller 28 can execute
the instructions stored in the computer-readable media 32 to
perform the method 40 illustrated in FIG. 4. The method 40 includes
obtaining reflection data from the radar device 36 (at block 42).
The reflection data can include timing information regarding radio
waves transmitted by the radar device 36 and corresponding
reflections detected by the radar device 36. It should be
understood that in some embodiments in addition to obtaining data
from the radar device 36, the controller 28 can be configured to
provide data to the radar device 36. For example, the controller 28
can be configured to provide control signals to the radar device 36
(e.g., to turn the radar device 36 on and off, to modify operating
parameters of the radar device 36, and/or to modify a physical
position and/or orientation of the radar device 36).
[0034] In some embodiments, the radio wave generated by the radar
device 36 reflects from many different materials, including steel,
coal, and individuals. Also, the range of the radio wave can be
approximately 200 meters. However, some detected objects within
this range may not be considered potential collision hazards. For
example, in some embodiments, only roof supports 18 that are no
more than two supports 18 ahead of the position of the shearer 10
(e.g., the upper drum 11a) in the current direction of travel of
the shearer 10 are considered potential collision hazards. Also, in
some situations, an operator can be legitimately positioned between
a shearer and a roof support 18 ahead of the shearer 10 in the
current direction of travel of the shearer 10.
[0035] Accordingly, the controller 28 can be configured to filter
the reflection data to identify those reflections associated with a
region of interest ("ROI"). For example, as illustrated in FIG. 5,
a radar device 36 can be configured to detect a radio wave having a
maximum possible angle and a minimum possible angle (e.g.,
approximately 13.degree. and approximately -13.degree.,
respectively) (see A and E in FIG. 5) from a neutral or horizontal
axis (see D in FIG. 5). Within this range of possible angles, a
maximum ROI angle and a minimum ROI angle can be defined (see B and
C in FIG. 5). Accordingly, the controller 28 can be configured to
process only reflections detected between the maximum ROI angle and
the minimum ROI to identify potential collision hazards. The
controller 28 can be configured with different ROI angle ranges for
different applications (e.g., different positions of the controller
28 and/or the radar device 36, different types of equipment,
different equipment configurations, different mine conditions,
etc.), which allows the controller 28 to accurately identify true
collision risks.
[0036] For example, depending on the nature of material being mined
(e.g., coal) it is not uncommon for the conveyor system 14 to
undulate and bend (see, e.g., FIGS. 6A-B). Although the conveyor
system 14 is specifically designed to accommodate such undulation
or bending, the radar device 36 may detect one or more roof
supports 18 as being potential collision hazards in these
situations when, in reality, the supports 18 are not hazards
because bends in the conveyor system 14 ahead of the shearer 10 in
its current direction of travel cause the shearer 10 to slew and
miss the roof support 18. Accordingly, the controller 28 can be
configured with a ROI as described to avoid falsely identifying
these roof supports as collision risks.
[0037] Furthermore, in some embodiments, the shearer 10 can include
an inertial navigation sensor ("INS"). The INS measures the profile
of the conveyor system 14 in one or more dimensions. Accordingly,
the controller 28 can be configured to receive information from the
INS and use the received information to identify any undulations or
bends in the conveyor system 14 ahead of the shearer 10 in its
current direction of travel. Therefore, the controller 28 can use
input derived from the INS in addition or as an independent of an
ROI to better judge whether potential collision risks detected by
the radar device 36 are genuine or false.
[0038] In addition and/or alternatively, the controller 28 can be
configured to apply a signal strength filter to the reflection data
to identify reflections from different surfaces or materials (e.g.,
metallic surfaces versus non-metallic surfaces). For example, the
controller 28 can be configured to identify whether a detected
reflection has a signal strength satisfying a predetermined
threshold or range (e.g., associated with reflections from metallic
surfaces). In some embodiments, the controller 28 can use multiple
thresholds or ranges of signal strengths to identify reflections
originating from a plurality of different surfaces (e.g., from
individuals, the cutting face 12, steel, etc.).
[0039] Accordingly, the ROI filter and/or the signal strength
filter can be used to discriminate between potential collision
hazards and other objects (currently considered not hazards). For
example, in one embodiment, the radar device 36 can be positioned
approximately 6 meters from the end of the shearer 10, and the
controller 28 can be configured to ignore all reflections from
non-metallic surfaces within approximately 6 meters from the radar
device 36, as these reflections may be from operators working in a
safe zone. Similarly, as another example, the radar device 36 can
be positioned at a predetermined angle to detect sprags 19, and the
controller 28 can be configured to ignore reflections from the
cutting face 12 and only process reflections from steel (i.e.,
sprags 19). As yet another example, the radar device 36 and/or
controller 28 can be configured to detect roof supports 18 relative
to a nominal thickness of the coal seam to detect roof supports 18
that are set low.
[0040] FIGS. 7A-B illustrate dimensions of the radar device 36
according to one embodiment of the invention. It should be
understood that in some embodiments, the radar device 36 and the
controller 28 are formed as an integrated device. In other
embodiments, these components are separate devices. Also, FIGS.
8A-C illustrate the positioning of the radar device 36 of FIGS.
7A-B on a surface of the shearer 10 according to one embodiment of
the invention. As illustrated in FIG. 8C (illustrating detail A as
marked in FIG. 8B), in the configuration illustrated in FIGS. 8A-C,
the radar device 36 can be mounted at approximately 13.degree. from
an upper surface of the shearer 10. In this configuration, the
controller 28 can filter reflection data to identify those
reflections originating from objects located greater than
approximately 6 meters and less than approximately 10 meters from
the radar devices that have an angle greater than approximately
0.degree. and less than approximately 13.degree., and have a signal
strength greater than approximately 70 dB (representing metallic
surfaces). Accordingly, as illustrated in FIG. 8C, the controller
28 can use these filtering parameters to ignore reflections from
roof supports 18 positioned in a normal or expected position (see
the three leftmost roof supports 18) while detecting a roof support
18 advanced out of sequence (see the rightmost roof support
18).
[0041] In some embodiments, although reflections from metallic
surfaces of the roof support system 17 and other metallic
components are detectable, the effectiveness of radar in any
application can be increased if an anti-stealth device is used that
reflects a radio wave back to the radar device 36 in a predictable
and efficient manner. For example, in one embodiment, a corner cube
reflector 50 (see, e.g., FIG. 9) can be deployed as a target for
radio waves generated by the radar device 36. As illustrated in
FIG. 10, an incident beam striking a corner cube reflector 50 goes
through a series of internal reflections and leaves the reflector
50 in the opposite direction from which it came (i.e., back toward
the radar device 36). Accordingly, corner cube reflectors 50 are
often referred to as "boomerang reflectors." Incorporating a corner
cube reflector 50 into mining equipment, such as the roof support
system 17, at one or more strategic location increases the accuracy
of the radar device 36 and the associated anti-collision
functionality performed by the controller 28. In particular, the
controller 28 can be configured to identify reflections from a
corner cube reflector 50 (i.e., reflections returning in the direct
opposite direction they were transmitted) to better identify those
reflections associated with true potential collision hazards (e.g.,
particular mining equipment or portions thereof).
[0042] In some embodiments, corner cube reflectors 50 can be
attached to or incorporated into (i.e., manufactured as part of the
structure of) roof support legs 18b, roof support canopies 18c,
and/or roof support sprags 19. For example, FIG. 11 illustrates a
side of a roof support canopy 18c including a corner cube reflector
50 (e.g., fitted in a recess of a canopy tip). In other
embodiments, the corner cube reflector 50 can be added to a piece
of mining machinery as an after-market addition. However, creating
the corner cube reflector 50 as part of the fabrication of the
equipment can provide robustness for mining environments. It should
be understood that although corner cube reflectors 50 are described
and illustrated in the present application, other types of
anti-stealth devices can be used to improve radar detection
accuracy.
[0043] Returning to FIG. 4, after obtaining the reflection data and
optionally filtering the reflection data as described above (e.g.,
ROI, INS, signal strength, corner cube reflections, etc.), the
controller 28 uses the reflection data to determine a position of
one or more objects detected around the radar device 36 (at block
60). It should be understood that the filtering and processing of
the reflection data as described in the present application can be
distributed in various configurations between the radar device 36
and the controller 28. For example, in some embodiments, the radar
device 36 provides raw timing data to the controller 28 and the
controller 28 performs the filtering and the processing. In other
embodiments, the radar device 36 is configured to perform at least
some of the filtering and processing prior to providing data to the
controller 28.
[0044] As noted above, the time between transmitting a wave and
detecting a reflection of the wave can be used to determine the
distance between the radar device 36 and the object reflecting the
wave and hence, a position of the object in terms of a distance
from the radar device 36 (e.g., "X" millimeters from the radar
device 36). Similarly, knowing the position of the radar device 36
relative to particular mining equipment (e.g., the shearer 10), the
controller 28 can use the determined distance between the radar
device 36 and the detected object to determine a position of the
detected object relative to the particular mining equipment (e.g.,
"X" millimeters from a cutter drum). Furthermore, based on known
mining environment dimensions, an absolute position of the object
reflecting a radio wave can be determined (e.g., in
longitude/latitude positions, a three-dimensional position, or
other geographical position).
[0045] After determining a position of at least one object, the
controller 28 compares the position to a predetermined threshold
(e.g., a distance threshold or range) to determine whether the
detected object poses a potential collision risk (at block 62).
When the determined position satisfies the threshold (e.g., falls
below the distance threshold or falls within the range), the
controller 28 performs one or more automatic actions (at block 64).
The automatic actions can include issuing a warning (e.g., a visual
warning, an audible warning, a tactile warning, or a combination
thereof) and/or modifying operation of one or more pieces of mining
equipment. It should be understood that in some embodiments, the
controller 28 can be configured to apply different thresholds to
determine what action to perform. For example, the controller 28
can be configured to issue a warning when a potential collision
hazard is within a predetermined "warning" distance from the
shearer 10 and stop the shearer 10 when the hazard is within a
predetermined "stop" distance from the shearer 10. Also, in some
embodiments, the controller 28 is configured to perform at least
one automatic action based on a type of a potential collision
hazard. For example, if, based on the reflection data, the
controller 28 identifies a detected object as a low canopy 18c
(e.g., based on the position of the detected object), the
controller 28 can perform a first action. However, if the
controller 28 identifies a detected object as an extended sprag 19,
the controller 28 can perform a second action different from the
first action.
[0046] When used to detect collisions between the shearer 10 and
the roof support system 17, the controller 28 can be configured to
automatically stop or slow the shearer 10 when a potential
collision is detected (e.g., an "out-of-sequence" roof support 18).
Alternatively or in addition, the controller 28 can be configured
to modify operation of the roof support system 17 to move the "out
of sequence" roof support 18 (e.g., retract the support 18).
[0047] To perform the automatic action(s), the controller 28 can be
configured to communicate with one or more controllers for the
mining machine equipment (e.g., through the input/output interface
34 using a wired and/or wireless connection). For example, the
controller 28 can be configured to send control signals to a
speaker or display (on the shearer 10 or remote from the shearer
10). Similarly, the controller 28 can be configured to send control
signals to a controller for the shearer 10 and/or the roof support
system 17 that manage movement of the shearer 10 and/or the roof
support system 17. The control signals instruct the controller(s)
how to move the shearer 10 and/or the roof support system 17. In
other embodiments, however, the controller 28 can be integrated
into these devices. In some embodiments, the controller 28 can also
be configured to communicate with other devices to obtain operating
conditions that the controller 28 can use to identify whether an
automatic action should be generated (e.g., is the shearer 10
moving, what direction is the shearer 10 traveling in, INS
information, fault information, etc.).
[0048] In some embodiments, the controller 28 can also be
configured to provide feedback to at least one operator based on
the process reflection data (e.g., regardless of whether the
controller 28 performs any automatic actions). For example, the
controller 28 can be configured to provide visual information to an
operator through a user interface. The user interface can display
reflection data and/or objects detected based on the reflection
data. The user interface can also display filtering parameters
applied by the controller 28. In some embodiments, the operator can
use the user interface to modify operation of the controller 28
(e.g., change filtering parameters, initiate one or more automatic
actions, change automatic action thresholds and/or ranges, etc.).
Optionally, the operator can also use the user interface to
override an automatic action performed by the controller 28.
[0049] It should be understood that the functionality performed by
the controller 28 as described in the present application can be
distributed among multiple controllers and/or devices (including,
for example, the radar device 36). As noted above, it should also
be understood that the controller 28 and the radar device 36 can be
combined as an integrated device or can be provided as separate
devices on the same or different pieces of equipment. For example,
in one embodiment, the controller 28 and the radar device 36 are
part of the shearer 10. In other embodiments, the radar device 36
is included on the shearer 10 and the controller 28 is included on
a separate device. In still other embodiments, the controller 28 is
included in the shearer 10 and the radar device 36 is installed on
the roof support system 17 (e.g., each roof support 18 includes its
own radar device 36 that can be used to determine a position of the
shearer 10). Furthermore, in some embodiments, the radar device 36
and/or the controller 28 is installed on a device configured to
move with the shearer 10 (e.g., along the conveyor system 14, such
as ahead of the shearer 10 in its current direction of travel). In
this situation and other situations, multiple radar devices 36 can
be used. For example, one radar device 36 can be used to determine
a position of the shearer 10 and/or a specific portion of a shearer
10 (e.g., one of the cutting drums) and a second radar device 36
can be used to determine a position of the roof support system 17.
It should also be understood that the anti-stealth devices
described herein can be mounted on any piece of mining equipment
and is not limited being used with the roof support system 17.
[0050] Thus, embodiments of the invention provide methods and
systems for using radar to detect objects in a travel path of a
shearer. As described above, the detected obstacles can include
roof supports advanced "out of sequence," support canopies that are
too low, sprags, and situations where the shearer is tilted
relative to the roof supports due to poor control of the shearer.
The systems and methods can use reflections from anti-stealth
devices incorporated into objects positions around a radar device
to increase the accuracy of detecting the objects. When a detected
object poses a potential collision risk, one or more automatic
actions can be performed including issues warnings and modifying
operation of the shearer and/or the detected object.
[0051] Various features and advantages of the invention are set
forth in the following claims.
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