Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
TITLE OF THE INVENTION:
WORK MACHINE REMOTE CONTROL SYSTEM
Field
[0001] The present disclosure relates to a remote
control system of a work machine.
Background
[0002] In a technical field related to a work machine, a
technique for remote control of the work machine is known.
In the remote control of the work machine, an image of a
work site where the work machine operates is captured by an
imaging apparatus. The image captured by the imaging
apparatus is transmitted to a remote place and displayed on
a display apparatus disposed in the remote place. An
operator in the remote place performs the remote control of
the work machine while viewing the image displayed on the
display apparatus. Patent Literature 1 discloses a
technique in which the imaging apparatus is disposed in a
cab of a swinging platform to capture an image in front of
the cab.
Citation List
Patent Literature
[0003] Patent Literature 1: JP 2019-068236 A
Summary
Technical Problem
[0004] A work machine performs work using working
equipment. In the work using the working equipment, an
impact may act on the working equipment. It is difficult
for an operator in a remote place to recognize the impact
acting on the working equipment. Therefore, there is a
possibility that the operator in the remote place performs
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remote control that results in applying an excessive impact
to the working equipment. When the excessive impact acts
on the working equipment, deterioration of the working
equipment may be accelerated.
[0005] It is therefore an object of the present
disclosure to make the operator in the remote place
recognize an impact that will act on the working equipment.
Solution to Problem
[0006] According to an aspect of the present invention,
a work machine remote control system comprises: a sensor
data reception unit configured to receive detection data of
an attitude of working equipment included in a work machine
operated by an operation signal from a remote place; an
alarm control unit configured to output an alarm control
signal when it is determined, based on the detection data,
that the working equipment is approaching or has reached an
end position in a movable range; and an alarm device
provided in the remote place and configured to output an
alarm based on the alarm control signal from the alarm
control unit.
Advantageous Effects of Invention
[0007] According to the present disclosure, it is
possible to make an operator in a remote place recognize an
impact that will act on working equipment.
Brief Description of Drawings
[0008] FIG. 1 is a schematic diagram illustrating a work
machine remote control system according to an embodiment.
FIG. 2 is a perspective view illustrating the work
machine according to the embodiment.
FIG. 3 is a side view illustrating the work machine
according to the embodiment.
FIG. 4 is a diagram illustrating a remote control room
according to the embodiment.
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FIG. 5 is a schematic diagram illustrating a hydraulic
system of the work machine according to the embodiment.
FIG. 6 is a functional block diagram illustrating the
work machine remote control system according to the
embodiment.
FIG. 7 is a schematic diagram illustrating a movable
range of components of working equipment according to the
embodiment.
FIG. 8 is a diagr'am illustrating a process by a first
image processing unit according to the embodiment.
FIG. 9 is a diagram illustrating a process by a
display control unit according to the embodiment.
FIG. 10 is a diagram illustrating a process by an
alarm control unit according to the embodiment.
FIG. 11 is a flowchart illustrating a remote control
method of the work machine according to the embodiment.
FIG. 12 is a block diagram illustrating a computer
system according to the embodiment.
FIG. 13 is a diagram illustrating an operation of the
work machine according to the embodiment.
FIG. 14 is a flowchart illustrating the remote control
method of the work machine according to the embodiment.
Description of Embodiments
[0009] Hereinafter, embodiments according to the present
disclosure will be described with reference to the
drawings. However, the present disclosure is not limited
thereto. Components of the embodiments described below can
be appropriately combined. Further, some components may
not be used.
[0010] In the embodiments, positional relationship of
each part will be described using terms of "left", "right",
"front", "back", "top", and "bottom". These terms indicate
relative positions or directions with respect to a center
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of a swinging platform 3 of a work machine 1.
[0011] [First embodiment]
<Remote control system>
FIG. 1 is a schematic diagram illustrating a remote
control system 100 of the work machine 1 according to an
embodiment. The remote control system 100 performs remote
control of the work machine 1 operating at a work site. An
example of the work site is a mine or a quarry.
[0012] At least a part of the remote control system 100
is disposed in a remote control room 200. The remote
control room 200 is installed in a remote place away from
the work site. The remote control system 100 includes a
remote controller 40, a display apparatus 50, and a control
apparatus 60.
[0013] The remote controller 40 is disposed in the
remote control room 200. The remote controller 40 is
operated by an operator in the remote control room 200.
The operator can operate the remote controller 40 in a
state seated on an operating seat 45.
[0014] The display apparatus 50 is disposed in the
remote control room 200. The display apparatus 50 displays
an image of the work site. The operator in the remote
control room 200 cannot directly visually recognize a
situation in the work site. The operator in the remote
control room 200 can visually recognize the situation in
the work site via the display apparatus 50.
[0015] The operator operates the remote controller 40
while viewing the image of the work site displayed on the
display apparatus 50. The work machine 1 is remotely
controlled by the remote controller 40.
[0016] The control apparatus 60 is disposed in the
remote control room 200. The control apparatus 60 includes
a computer system.
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[0017] The work machine 1 is provided with a control
apparatus 300. The control apparatus 300 includes a
computer system.
[0018] The control apparatus 60 and the control
5 apparatus 300 communicate with each other via a
communication system 400. Examples of the communication
system 400 include the Internet, a local area network
(LAN), a mobile phone communication network, and a
satellite communication network. The communication system
400 may include a relay station that relays data to be
communicated.
[0019] <Work machine>
FIG. 2 is a perspective view illustrating the work
machine 1 according to the embodiment. FIG. 3 is a side
view illustrating the work machine 1 according to the
embodiment. In the embodiment, it is assumed that the work
machine 1 is an excavator that is one type of loading
machine. The work machine 1 operates at the work site.
The work machine 1 operates, for example, in a loading area
of the work site. The work machine 1 performs excavation
of a work target. Examples of the work target include
earth and sand or ore. In addition, a dump truck, which is
one type of a haulage vehicle, operates at the work site.
The work machine 1 performs loading work to load a cargo
onto the dump truck. As the cargo, an excavated object
excavated by excavation is exemplified.
[0020] As illustrated in FIGS. 2 and 3, the work machine
1 includes a traveling body 2, a swinging platform 3
supported by the traveling body 2, working equipment 4
mounted on the swinging platform 3, a hydraulic cylinder 5
that drives the working equipment 4, a position sensor 71
that detects a position of the work machine 1, a vehicle
attitude sensor 72 that detects an attitude of the swinging
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platform 3, a working equipment attitude sensor 73 that
detects an attitude of the working equipment 4, and an
imaging apparatus 30.
[0021] The traveling body 2 travels in a state of
supporting the swinging platform 3. The swinging platform
3 is a vehicle body of the work machine 1. Traveling body
2 is disposed below the swinging platform 3. The traveling
body 2 rotatably supports the swinging platform 3. The
traveling body 2 includes a drive wheel 2A, a driven wheel
28, and a crawler 20 supported by the drive wheel 2A and
the driven wheel 2B. Each of the drive wheel 2A and the
driven wheel 2B rotates about a rotation axis DX. A pair
of drive wheels 2A, a pair of driven wheels 2B, and a pair
of crawlers 2C are provided. The crawler 20 is rotated by
the rotation of the drive wheel 2A. When the crawler 2C
rotates, the traveling body 2 travels.
[0022] The swinging platform 3 can swing about a swing
axis RX in the state of being supported by the traveling
body 2. The swing axis RX extends in a top-bottom
direction. The swinging platform 3 includes a cab 3A, a
lower deck 3B, a step 30, and an upper deck 3D. The cab 3A
is an internal space of the swinging platform 3 where an
operator can board. The cab 3A is disposed at a front and
upper part of the swinging platform 3. The lower deck 3B
is disposed at a back and lower part of the swinging
platform 3. The upper deck 3D is disposed at the front and
upper part of the swinging platform 3. Step 30 connects
the lower deck 3B and the upper deck 3D. The upper deck 3D
is disposed around the cab 3A. At least a part of the
upper deck 3D is disposed in front of the cab 3A. A fence-
like handrail 3E is arranged in each of the lower deck 3B,
the step 30, and the upper deck 3D.
[0023] Each of the lower deck 3B, the step 30, and the
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upper deck 3D includes a passage through which the operator
can pass. The operator can board the cab 3A by passing the
lower deck 3B, the step 3C, and the upper deck 3D.
[0024] The swinging platform 3 includes a ladder 3F.
The ladder 3F is connected to the upper deck 3D.
[0025] The working equipment 4 is mounted on the front
part of the swinging platform 3. The working equipment 4
is disposed in front of the swing axis RX. The working
equipment 4 is operable to extend forward. The working
equipment 4 includes a boom 4A connected to the swinging
platform 3, an arm 4B connected to the boom 4A, and a
bucket 4C connected to the arm 4B. A proximal end part of
the boom 4A is connected to the front part of the swinging
platform 3 via a pin. The proximal end part of the arm 43
is connected to a distal end part of the boom 4A via a pin.
A proximal end part of the bucket 4C is connected to a
distal end part of the arm 4B via a pin. The bucket 4C has
a tip blade 4D. The bucket 4C excavates the work target.
[0026] The boom 4A is connected to the front part of the
swinging platform 3 so as to be rotatable about a boom
rotation axis AX. The arm 4B is connected to the boom 4A
so as to be rotatable about an arm rotation axis BX. The
bucket 4C is connected to the arm 4B so as to be rotatable
about a bucket rotation axis CX.
[0027] The boom rotation axis AX, the arm rotation axis
BX, and the bucket rotation axis CX are parallel. Each of
the boom rotation axis AX, the arm rotation axis BX, and
the bucket rotation axis CX extends in a vehicle width
direction of the swinging platform 3.
[0028] In the embodiment, the work machine 1 is a
loading excavator. The loading excavator is an excavator
in which the bucket 4C is attached to the arm 4B such that
the tip blade 4D of the bucket 4C faces forward.
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[0029] The hydraulic cylinder 5 includes a boom cylinder
5A that drives the boom 4A, an arm cylinder 58 that drives
the arm 48, and a bucket cylinder 50 that drives the bucket
40. A proximal end part of the boom cylinder 5A is
connected to the swinging platform 3. A distal end part of
the boom cylinder 5A is connected to the boom 4A. A
proximal end part of the arm cylinder 5B is connected to
the boom 4A. A distal end part of the arm cylinder 58 is
connected to the arm 4B. A proximal end part of the bucket
cylinder 50 is connected to the boom 4A. A distal end part
of the bucket cylinder 50 is connected to the bucket 40.
[0030] The position sensor 71 detects the position of
the work machine 1. The position sensor 71 detects an
absolute position of the work machine 1 using a global
navigation satellite system (GNSS). The position sensor 71
includes a GNSS receiver provided in the swinging platform
3.
[0031] The vehicle attitude sensor 72 detects the
attitude of the swinging platform 3. The attitude of the
swinging platform 3 includes an inclination angle (roll,
pitch) of the swinging platform 3 with respect to a
horizontal plane. The vehicle attitude sensor 72 includes
an inertial measurement unit (IMU) provided in the swinging
platform 3.
25 [0032] The working equipment attitude sensor 73 detects
the attitude of the working equipment 4. The attitude of
the working equipment 4 includes an angle of the working
equipment 4. The working equipment attitude sensor 73
includes a boom attitude sensor 73A that detects an angle
of the boom 4A with respect to the swinging platform 3, an
arm attitude sensor 73B that detects an angle of the arm 4B
with respect to the boom 4A, and a bucket attitude sensor
730 that detects an angle of the bucket 40 with respect to
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the arm 43.
[0033] .. In the embodiment, the working equipment attitude
sensor 73 is a stroke sensor disposed in the hydraulic
cylinder 5. The hydraulic cylinder 5 includes a cylinder
tube, a piston that moves inside the cylinder tube, and a
rod connected to the piston. The stroke sensor detects a
stroke length of the hydraulic cylinder 5 indicating a
movement distance of the rod. The stroke length refers to
a movement distance of the rod from the stroke end of the
hydraulic cylinder 5. The stroke end refers to an end
position in a movable range of the rod. In other words,
the stroke end refers to a position of the rod in a state
that the hydraulic cylinder 5 is most contracted or a
position of the rod in a state that the hydraulic cylinder
5 is most extended.
[0034] The boom attitude sensor 73A is a stroke sensor
disposed in the boom cylinder 5A. The boom attitude sensor
73A detects a stroke length of the boom cylinder 5A.
[0035] .. The arm attitude sensor 733 is a stroke sensor
disposed in the arm cylinder 5B. The arm attitude sensor
73B detects a stroke length of the arm cylinder 5B.
[0036] The bucket attitude sensor 73C is a stroke sensor
disposed in the bucket cylinder 5C. The bucket attitude
sensor 73C detects a stroke length of the bucket cylinder
5C.
[0037] The imaging apparatus 30 captures the work site
to acquire an image of the work site. The imaging
apparatus 30 is disposed in the swinging platform 3. The
imaging apparatus 30 is fixed to the swinging platform 3.
(0038] Examples of the image of the work site acquired
by the imaging apparatus 30 include an image of the work
target of the work machine 1, an image of at least a part
of the work machine 1, an image of a structure existing at
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the work site, an image of a work machine different from
the work machine 1, and an image of a worker working at the
work site. In the embodiment, the image of the work target
of the work machine 1 includes an image of an excavation
5 target of the working equipment 4.
[0039] The imaging apparatus 30 includes an optical
system and an image sensor that receives light passing
through the optical system. The image sensor includes a
couple charged device (CCD) image sensor or a complementary
10 metal oxide semiconductor (CMOS) image sensor.
[0040] In the embodiment, the imaging apparatus 30
captures an image in an imaging range M. The imaging range
M is set to include the work target of the work machine 1.
[0041] In the embodiment, the top-bottom direction is a
direction parallel to the swing axis RX. A left-right
direction is a direction parallel to the boom rotation axis
AX. A front-back direction is a direction orthogonal to
both the boom rotation axis AX and the swing axis RX. A
direction in which the swinging platform 3 exists with
reference to a ground contact surface of the traveling body
2 is toward top, and a direction opposite to the top is
bottom. One of the left and right directions with
reference to the swing axis RX is right, and a direction
opposite to the right is left. A direction in which the
working equipment 4 exists with reference to the swing axis
RX is front, and a direction opposite to the front is back.
[0042] In the embodiment, the imaging apparatus 30 is
disposed in the cab 3A. An optical axis OA of the optical
system of the imaging apparatus 30 extends in the front-
back direction.
[0043] In the following description, an image in the
imaging range M captured by the imaging apparatus 30 is
referred to as an image P as appropriate.
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[0044] <Remote control room>
FIG. 4 is a diagram illustrating the remote control
room 200 according to the embodiment. As illustrated in
FIG. 4, the remote controller 40 and the display apparatus
50 are disposed in the remote control room 200.
[0045] The remote controller 40 is operated by the
operator seated on the operating seat 45. The operator
sits on the operating seat 45 so as to face a display
screen of the display apparatus 50. The operator operates
the remote controller 40 while viewing the display screen
of the display apparatus 50.
[0046] An operation signal generated by operating the
remote controller 40 is transmitted to the control
apparatus 300 of the work machine 1 via the control
apparatus 60 and the communication system 400. The control
apparatus 300 operates the work machine 1 according to the
operation signal acquired via the communication system 400.
The work machine 1 is operated by the operation signal from
the remote place of the work machine 1. An operation of
the work machine 1 includes at least one of an operation of
the traveling body 2, an operation of the swinging platform
3, and an operation of the working equipment 4.
[0047] The operation of the traveling body 2 includes a
forward operation and a backward operation of the traveling
body 2. The operation of the swinging platform 3 includes
a left swing operation and a right swing operation of the
swinging platform 3. The operation of the working
equipment 4 includes an elevating operation of the boom 4A,
a lowering operation of the boom 4A, a dumping operation of
the arm 4B, an excavating operation of the arm 48, an
excavating operation of the bucket 40, and a dumping
operation of the bucket 40.
[0048] The remote controller 40 includes a left working
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lever 41 and a right working lever 42 operated for the
operation of the swinging platform 3 and the working
equipment 4, and a left travel pedal 43 and a right travel
pedal 44 operated for the operation of the traveling body
2.
[0049] The left working lever 41 is disposed on a left
side of the operating seat 45. The right working lever 42
is disposed on a right side of the operating seat 45. As
an example, when the left working lever 41 is operated in
the front-back direction, the arm 43 performs the dumping
operation or the excavating operation. When the left
working lever 41 is operated in the left-right direction,
the swinging platform 3 performs the left swing operation
or the right swing operation. When the right working lever
42 is operated in the left-right direction, the bucket 4C
performs the excavating operation or the dumping operation.
When the right working lever 42 is operated in the front-
back direction, the boom 4A performs the lowering operation
or the elevating operation. Note that when the left
working lever 41 is operated in the front-back direction,
the swinging platform 3 may perform the right swing
operation or the left swing operation, and when the left
working lever 41 is operated in the left-right direction,
the arm 4B may perform the dumping operation or the
excavating operation. The operating direction of the left
working lever 41 and the operating direction of the right
working lever 42 are arbitrarily related to the operation
of the working equipment 4.
[0050] The left travel pedal 43 and the right travel
pedal 44 are disposed on a front lower part of the
operating seat 45. The left travel pedal 43 is disposed to
the left of the right travel pedal 44. When the left
travel pedal 43 is operated, the crawler 20 on the left
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side of the traveling body 2 moves forward or backward.
When the right travel pedal 44 is operated, the crawler 20
on the right side of the traveling body 2 moves forward or
backward.
[0051] In the remote control room 200, a first monitor
device 501 that displays work machine operation data
indicating an operation status of the work machine 1 and an
operation switch 502 that is operated to activate an
electric apparatus equipped in the work machine 1 are
disposed. The first monitor device 501 displays, for
example, a remaining amount of fuel of an engine mounted on
the work machine 1, a temperature of coolant of the engine,
a temperature of hydraulic oil for driving the hydraulic
cylinder 5, and a traveling speed of the traveling body 2
as the work machine operation data. The operation switch
502 operates, for example, a headlight provided in the work
machine 1 as the electric apparatus equipped in the work
machine 1.
[0052] The display apparatus 50 displays the image P
transmitted from the work machine 1. The image P is
transmitted to the control apparatus 60 of the remote
control system 100 via the control apparatus 300 and the
communication system 400. The control apparatus 60 causes
the display apparatus 50 to display the image P acquired
via the communication system 400.
[0053] The display apparatus 50 includes a flat panel
display such as a liquid crystal display (LCD) or an
organic electroluminescence display (OELD). In the
embodiment, the display apparatus 50 includes a plurality
of flat panel displays arranged adjacent to each other. In
the embodiment, the display apparatus 50 includes a central
display 51, a left display 52 disposed on a left side of
the central display 51, a right display 53 disposed on a
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right side of the central display 51, an upper display 54
disposed above the central display 51, and a lower display
55 disposed below the central display 51.
[0054] The image P displayed on the display apparatus 50
is an image corresponding to a field of view of a front
space of the operator when the operator is assumed to be
seated on a driver seat provided in the cab 3A of the work
machine 1. The operator in the remote control room 200 can
obtain a feeling of actually sitting on the driver's seat
of the work machine 1.
[0055] The operator in the remote control room 200
operates the remote controller 40 to operate the working
equipment 4 and excavate the work target. The excavated
object excavated by the bucket 4C of the working equipment
4 is loaded onto the dump truck as a cargo.
[0056] In the embodiment, the dump truck is an unmanned
dump truck that travels according to a control command
transmitted from a control facility in the work site. In
the remote control room 200, a second monitor device 503 is
arranged to display dump truck operation data indicating an
operation status of the unmanned dump truck at the work
site. In the unmanned dump truck, a position sensor is
disposed to detect position data of the unmanned dump
truck. The position sensor detects an absolute position of
the unmanned dump truck using the global navigation
satellite system (GNSS). The second monitor device 503
displays a position of each of the plurality of unmanned
dump trucks operating at the work site as the dump truck
operation data. In addition, the operator can stop or
start the unmanned dump truck by operating an input unit
provided in the second monitor device 503.
[0057] In the remote control room 200, a third monitor
device 504 is disposed to display guidance data of the
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working equipment 4. As the guidance data, a relative
distance between a target design surface of the work target
and the working equipment 4, a shape of the work target,
and an ore distribution of the work target are exemplified.
5 [0058] <Hydraulic system>
FIG. 5 is a schematic diagram illustrating a hydraulic
system 20 of the work machine 1 according to the
embodiment. As illustrated in FIG. 5, the hydraulic system
includes a hydraulic pump 21, the hydraulic cylinder 5
10 that drives the working equipment 4 according to the
hydraulic oil supplied from the hydraulic pump 21, a pump
flow path 22 connected to the hydraulic pump 21, a flow
rate control valve 23 that adjusts the flow rate of the
hydraulic oil supplied to the hydraulic cylinder 5 via the
15 pump flow path 22, and a pressure sensor 74 that detects a
pressure of the hydraulic oil in the hydraulic cylinder 5.
[0059] The hydraulic pump 21 is driven by power
transmitted from a power source of the work machine 1. As
the power source of the work machine 1, a diesel engine or
20 an electric motor is exemplified. The hydraulic pump 21
discharges the hydraulic oil. In the embodiment, the
hydraulic pump 21 is a variable displacement hydraulic
pump.
[0060] The hydraulic cylinder 5 operates the working
equipment 4 according to the hydraulic oil supplied from
the hydraulic pump 21. The working equipment 4 operates
within a predetermined movable range. The hydraulic
cylinder 5 includes the boom cylinder 5A that operates the
boom 4A, the arm cylinder 5B that operates the arm 4B, and
the bucket cylinder 5C that operates the bucket 4C.
[0061] The hydraulic cylinder 5 includes a bottom
chamber BR and a rod chamber RR. When the hydraulic oil is
supplied to the bottom chamber BR, the hydraulic cylinder 5
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extends. When the hydraulic oil is supplied to the rod
chamber RR, the hydraulic cylinder 5 contracts.
[0062] The flow rate control valve 23 adjusts the flow
rate of the hydraulic oil supplied to the hydraulic
cylinder 5. The flow rate control valve 23 includes a boom
flow rate control valve 23A that adjusts the flow rate of
the hydraulic oil supplied to the boom cylinder 5A, an arm
flow rate control valve 23B that adjusts the flow rate of
the hydraulic oil supplied to the arm cylinder 5B, and a
bucket flow rate control valve 23C that adjusts the flow
rate of the hydraulic oil supplied to the bucket cylinder
5C.
[0063] The flow rate control valve 23 includes a pump
port Pa, a bottom port Pb, a rod port Pc, and a tank port
Pd.
[0064] The pump port Pa is connected to the hydraulic
pump 21 via a supply flow path 24 and the pump flow path
22. The bottom port Pb is connected to the bottom chamber
BR of the hydraulic cylinder 5 via a bottom flow path 25.
The rod port Pc is connected to the rod chamber RR of the
hydraulic cylinder 5 via a rod flow path 26. The tank port
Pd is connected to a tank 28 via a discharge flow path 27.
[0065] The hydraulic oil discharged from the hydraulic
pump 21 can flow through the pump flow path 22 and the
supply flow path 24 and then flow into the flow rate
control valve 23 from the pump port Pa. The hydraulic oil
flowing out from the bottom port Pb can flow into the
bottom chamber BR of the hydraulic cylinder 5 after flowing
through the bottom flow path 25. The hydraulic oil flowing
out from the bottom chamber BR of the hydraulic cylinder 5
can flow through the bottom flow path 25 and then flow into
the flow rate control valve 23 from the bottom port Pb.
The hydraulic oil flowing out from the rod port Pc can flow
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into the rod chamber RR of the hydraulic cylinder 5 after
flowing through the rod flow path 26. The hydraulic oil
flowing out from the rod chamber RR of the hydraulic
cylinder 5 can flow through the rod flow path 26 and then
flow into the flow rate control valve 23 from the rod port
Pc. The hydraulic oil flowing out from the tank port Pd
flows through the discharge flow path 27 and then is
discharged to the tank 28.
[0066] The flow rate control valve 23 is a slide spool
type flow rate control valve that switches the flow rate
and direction of the hydraulic oil supplied to the
hydraulic cylinder 5 by moving a rod-shaped spool. When
the spool moves in an axial direction, the supply of the
hydraulic oil to the bottom chamber BR and the supply of
the hydraulic oil to the rod chamber RR are switched. In
addition, the flow rate of the hydraulic oil supplied to
the hydraulic cylinder 5 is adjusted according to a
movement amount of the spool.
[0067] The spool of the flow rate control valve 23 moves
to a first operating position Q1 at which the hydraulic oil
is supplied to the bottom chamber BR of the hydraulic
cylinder 5, a second operating position Q2 at which the
hydraulic oil is supplied to the rod chamber RR of the
hydraulic cylinder 5, and a stop position Q3 arranged
between the first operating position Q1 and the second
operating position Q2 and at which the hydraulic oil does
not flow.
[0068] When the spool of the flow rate control valve 23
is arranged at the first operating position Ql, the
hydraulic oil discharged from the hydraulic pump 21 flows
through the pump flow path 22 and the supply flow path 24,
then flows into the flow rate control valve 23 from the
pump port Pa, and flows out from the bottom port Pb. The
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hydraulic oil flowing out from the bottom port Pb flows
through the bottom flow path 25 and then flows into the
bottom chamber BR of the hydraulic cylinder 5. As a
result, the hydraulic cylinder 5 extends. When the
hydraulic cylinder 5 extends, the hydraulic oil flows out
from the rod chamber BR. The hydraulic oil flowing out
from the rod chamber BR of the hydraulic cylinder 5 flows
through the rod flow path 26, then flows into the flow rate
control valve 23 from the rod port Pc, and flows out from
the tank port Pd. The hydraulic oil flowing out from the
tank port Pd is discharged to the tank 28 via the discharge
flow path 27.
[0069] When the spool of the flow rate control valve 23
is arranged at the second operating position Q2, the
hydraulic oil discharged from the hydraulic pump 21 flows
through the pump flow path 22 and the supply flow path 24,
then flows into the flow rate control valve 23 from the
pump port Pa, and flows out from the rod port Pc. The
hydraulic oil flowing out from the rod port Pc flows
through the rod flow path 26 and then flows into the rod
chamber RR of the hydraulic cylinder 5. As a result, the
hydraulic cylinder 5 contracts. When the hydraulic
cylinder 5 contracts, the hydraulic oil flows out from the
bottom chamber BR. The hydraulic oil flowing out from the
bottom chamber BR of the hydraulic cylinder 5 flows through
the bottom flow path 25, then flows into the flow rate
control valve 23 from the bottom port Pb, and flows out
from the tank port Pd. The hydraulic oil flowing out from
the tank port Pd is discharged to the tank 28 via the
discharge flow path 27.
[0070] When the spool of the flow rate control valve 23
is arranged at the stop position Q3, the hydraulic oil
cannot flow through the flow rate control valve 23. The
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hydraulic cylinder 5 does not extend or contract.
[0071] The pressure sensor 74 detects the pressure of
the hydraulic oil in the hydraulic cylinder 5. The
pressure sensor 74 includes a boom pressure sensor 74A that
detects the pressure of the hydraulic oil in the boom
cylinder 5A, an arm pressure sensor 743 that detects the
pressure of the hydraulic oil in the arm cylinder 5B, and a
bucket pressure sensor 74C that detects the pressure of the
hydraulic oil in the bucket cylinder 5C.
[0072] In the embodiment, the pressure sensor 74 detects
the pressure of the hydraulic oil supplied to the hydraulic
cylinder 5. The pressure sensor 74 is provided in each of
the bottom flow path 25 and the rod flow path 26. When the
hydraulic oil is supplied to the rod chamber RR and the
hydraulic cylinder 5 contracts, the pressure sensor 74
provided in the rod flow path 26 detects the pressure of
the hydraulic oil supplied to the hydraulic cylinder 5.
When the hydraulic oil is supplied to the bottom chamber BR
and the hydraulic cylinder 5 extends, the pressure sensor
74 provided in the bottom flow path 25 detects the pressure
of the hydraulic oil supplied to the hydraulic cylinder 5.
The pressure sensor 74 may be provided in each of the
bottom chamber BR and the rod chamber RR.
[0073] <Control apparatus>
FIG. 6 is a functional block diagram illustrating the
remote control system 100 of the work machine 1 according
to the embodiment. As illustrated in FIG. 6, the remote
control system 100 includes a communication device 6
disposed in a remote place, the control apparatus 60
connected to the communication device 6, the remote
controller 40 connected to the control apparatus 60, and
the display apparatus 50 connected to the control apparatus
60. In addition, the remote control system 100 includes a
, CA 01182563 2022-11-04
communication device 7 disposed in the work machine 1, the
control apparatus 300 connected to the communication device
7, the imaging apparatus 30 connected to the control
apparatus 300, a sensor 70 connected to the control
5 apparatus 300, the traveling body 2 controlled by the
control apparatus 300, the swinging platform 3 controlled
by the control apparatus 300, and the hydraulic cylinder 5
controlled by the control apparatus 300. The sensor 70
includes the position sensor 71, the vehicle attitude
10 sensor 72, the working equipment attitude sensor 73, and
the pressure sensor 74.
[0074] The control apparatus 300 includes a traveling
body control unit 301, a swinging platform control unit
302, a working equipment control unit 303, a stroke end
15 determination unit 304, an image data transmission unit
305, and a sensor data transmission unit 306.
[0075] The traveling body control unit 301 receives an
operation signal of the remote controller 40 transmitted
from the control apparatus 60. The traveling body control
20 unit 301 outputs a control signal for controlling the
operation of the traveling body 2 according to the
operation signal of the remote controller 40.
[0076] The swinging platform control unit 302 receives
the operation signal of the remote controller 40
transmitted from the control apparatus 60. The swinging
platform control unit 302 outputs a control signal for
controlling the operation of the swinging platform 3
according to the operation signal of the remote controller
40.
[0077] The working equipment control unit 303 receives
the operation signal of the remote controller 40
transmitted from the control apparatus 60. The working
equipment control unit 303 outputs a control signal for
CA331E)221322-11-04
)
21
controlling the operation of the working equipment 4
according to the operation signal of the remote controller
40. The control signal for controlling the operation of
the working equipment 4 includes a control signal for
controlling the operation of the hydraulic cylinder 5. The
control signal for controlling the operation of the
hydraulic cylinder 5 includes a control signal for
controlling the flow rate control valve 23.
[0078] The stroke end determination unit 304 calculates
an angle of the working equipment 4 based on detection data
of the working equipment attitude sensor 73. The angle of
the working equipment 4 and the stroke length of the
hydraulic cylinder 5 are correlated. The stroke end
determination unit 304 can calculate the angle of the
working equipment 4 by performing arithmetic processing
based on the detection data of the working equipment
attitude sensor 73. The stroke end determination unit 304
can calculate the angle of the boom 4A with respect to the
swinging platform 3 by performing arithmetic processing
based on detection data of the boom attitude sensor 73A.
The stroke end determination unit 304 can calculate the
angle of the arm 4B with respect to the boom 4A by
performing arithmetic processing based on detection data of
the arm attitude sensor 733. The stroke end determination
unit 304 can calculate an angle of the bucket 4C with
respect to the arm 4B by performing arithmetic processing
based on detection data of the bucket attitude sensor 73C.
[0079] Further, the stroke end determination unit 304
can calculate a cylinder position of the hydraulic cylinder
5 based on the detection data of the working equipment
attitude sensor 73. The cylinder position refers to a
relative position of the rod with respect to the stroke end
of the hydraulic cylinder 5. As described above, the
, CA 01182563 2022-11-04
22
stroke end refers to an end position of the rod in the
movable range. The stroke end determination unit 304 can
calculate a cylinder position of the boom cylinder 5A by
performing arithmetic processing based on the detection
data of the boom attitude sensor 73A. The stroke end
determination unit 304 can calculate a cylinder position of
the arm cylinder 5B by performing arithmetic processing
based on the detection data of the arm attitude sensor 73B.
The stroke end determination unit 304 can calculate a
cylinder position of the bucket cylinder 5C by performing
arithmetic processing based on the detection data of the
bucket attitude sensor 730.
[0080] In addition, the stroke end determination unit
304 can calculate the stroke length of the hydraulic
cylinder 5 based on the detection data of the working
equipment attitude sensor 73. As described above, the
stroke length refers to the movement distance of the rod
from the stroke end of the hydraulic cylinder 5.
[0081] In addition, the stroke end determination unit
304 can calculate a cylinder speed of the hydraulic
cylinder 5 based on the detection data of the working
equipment attitude sensor 73. The cylinder speed refers to
a speed of the rod with respect to the cylinder tube of the
hydraulic cylinder 5. The stroke end determination unit
304 can calculate a cylinder speed of the boom cylinder 5A
by performing arithmetic processing based on the detection
data of the boom attitude sensor 73A. The stroke end
determination unit 304 can calculate a cylinder speed of
the arm cylinder 58 by performing arithmetic processing
based on the detection data of the arm attitude sensor 738.
The stroke end determination unit 304 can calculate a
cylinder speed of the bucket cylinder 5C by performing
arithmetic processing based on the detection data of the
CA3318256321322-11-134
=
23
bucket attitude sensor 730.
[0082] In other words, in the embodiment, the working
equipment attitude sensor 73 can function as at least one
of an angle sensor of the working equipment 4, a cylinder
position sensor of the hydraulic cylinder 5, a stroke
length sensor of the hydraulic cylinder 5, and a cylinder
speed sensor of the hydraulic cylinder 5.
[0083] Note that the working equipment attitude sensor
73 may include an angle sensor capable of detecting the
angle of the working equipment 4 such as a potentiometer.
Still more, the working equipment attitude sensor 73 may be
an inertial measurement unit (IMU) provided in the working
equipment 4.
[0084] The stroke end determination unit 304 determines
whether the working equipment 4 approaches the end position
in the movable range based on the detection data of the
working equipment attitude sensor 73.
[0085] FIG. 7 is a schematic diagram illustrating the
movable range of the working equipment 4 according to the
embodiment. The working equipment 4 includes a plurality
of working equipment components that can be relatively
moved. The working equipment components of the working
equipment 4 include the boom 4A, the arm 4B, and the bucket
40. In the following description, the movable range of the
working equipment 4 is the movable range of the working
equipment components.
[0086] The working equipment 4 can move within the
movable range determined by the stroke of the hydraulic
cylinder 5. The movable range of the working equipment 4
is determined based on the movable range of the rod of the
hydraulic cylinder 5. The end position in the movable
range of the working equipment 4 is defined based on the
stroke end of the hydraulic cylinder 5. When the hydraulic
, CA 01182563 2022-11-04
24
cylinder 5 reaches the stroke end, the working equipment 4
reaches the end position in the movable range.
[0087] In the embodiment, an end zone, an alarm zone,
and an intermediate zone are defined in the movable range
of the working equipment 4. The end zone is a part of the
movable range including the end position. The intermediate
zone is a part of the movable range including a central
position of the movable range. The alarm zone is a part of
the movable range between the end zone and the central
position. In the embodiment, the alarm zone is a section
between the end zone and the intermediate zone. The alarm
zone is defined so as to be adjacent to each of the end
zone and the intermediate zone. As described later, when
the working equipment 4 approaches the end position in the
alarm zone, an alarm is output in the remote place.
[0088] The alarm zone may be included in the end zone.
The alarm zone may be omitted.
[0089] A ratio of a length of the end zone to the
movable range can be arbitrarily set. The end zone may
have an arbitrary ratio from 1 [%] to 20 [%], inclusive, of
the movable range. Similarly, a ratio of a length of the
alarm zone to the movable range can be arbitrarily set.
The alarm zone may be an arbitrary ratio from 1 [%] to 20
[%], inclusive, of the movable range. The length of the
end zone is shorter than the length of the intermediate
zone.
[0090] The stroke end determination unit 304 determines
whether the working equipment 4 exists in the end zone
including the end position in the movable range based on
the detection data of the working equipment attitude sensor
73. The end position in the movable range of the working
equipment 4 is defined based on the stroke end of the
hydraulic cylinder 5. The end zone of the movable range of
, CA 01182563 2022-11-04
the working equipment 4 is defined based on the stroke
length of the hydraulic cylinder 5. The stroke end
determination unit 304 can determine whether the working
equipment 4 exists in the end zone of the movable range
5 based on the detection data of the working equipment
attitude sensor 73.
[0091] Similarly, the stroke end determination unit 304
can determine whether or not the working equipment 4 exists
in the alarm zone between the end zone and the central
10 position of the movable range based on the detection data
of the working equipment attitude sensor 73. The stroke
end determination unit 304 can determine whether the
working equipment 4 exists in the intermediate zone
including the central position of the movable range based
15 on the detection data of the working equipment attitude
sensor 73.
[0092] In the embodiment, the working equipment control
unit 303 performs cushion control. The cushion control is
control to decelerate the rod when the rod of the hydraulic
20 cylinder 5 approaches the stroke end. In the cushion
control, the working equipment control unit 303 decelerates
the rod more than the cylinder speed set based on the
operation signal generated by the remote controller 40. In
the cushion control, the speed of the rod decreases as a
25 distance between the rod of the hydraulic cylinder 5 and
the stroke end decreases. The cushion control reduces
impact when the rod of the hydraulic cylinder 5 reaches the
stroke end.
[0093] When the stroke end determination unit 304
determines that the working equipment 4 is close to the end
position in the movable range, the working equipment
control unit 303 outputs, to the flow rate control valve
23, a control command for reducing the flow rate of the
, CA 01182563 2022-11-04
26
hydraulic oil supplied to the hydraulic cylinder 5. As a
result, the cushion control to reduce the speed of the
working equipment 4 approaching the end position is
performed. In the cushion control, the speed of the
working equipment 4 decreases as the distance between the
working equipment 4 and the end position decreases. The
speed of the working equipment 4 may be gradually reduced
as the distance between the working equipment 4 and the end
position becomes shorter, or may be reduced stepwise. In
the cushion control, when the working equipment 4 reaches
the end position, the speed of the working equipment 4 may
or may not be zero.
[0094] In the embodiment, the cushion control is
performed when the working equipment 4 is arranged in the
end zone and the working equipment 4 is operated to
approach the end position. In other words, when the stroke
end determination unit 304 determines that the working
equipment 4 approaches the end position in the end zone,
the working equipment control unit 303 outputs, to the flow
rate control valve 23, the control command for reducing the
flow rate of the hydraulic oil supplied to the hydraulic
cylinder 5. Accordingly, when the working equipment 4
approaches the end position in the end zone, the cushion
control for reducing the speed of the working equipment 4
is performed.
[0095] For example, when the stroke end determination
unit 304 determines that the boom 4A is operated to
approach the end position in the end zone of the movable
range, the working equipment control unit 303 outputs, to
the boom flow rate control valve 23A, a control command for
reducing the flow rate of the hydraulic oil supplied to the
boom cylinder 5A. When the stroke end determination unit
304 determines that the arm 43 is operated to approach the
. CA 01182563 2022-11-04
27
end position in the end zone of the movable range, the
working equipment control unit 303 outputs, to the arm flow
rate control valve 23B, a control command for reducing the
flow rate of the hydraulic oil supplied to the arm cylinder
5B. When the stroke end determination unit 304 determines
that the bucket 4C is operated to approach the end position
in the end zone of the movable range, the working equipment
control unit 303 outputs, to the bucket flow rate control
valve 23C, a control command for reducing the flow rate of
the hydraulic oil supplied to the bucket cylinder 5C.
[0096] The image data transmission unit 305 transmits an
image around the work machine 1 acquired by the imaging
apparatus 30 to the control apparatus 60. The image data
transmission unit 305 acquires the image P in the imaging
range M from the imaging apparatus 30. The image data
transmission unit 305 transmits the image P to the control
apparatus 60.
[0097] The sensor data transmission unit 306 transmits
detection data of the sensor 70 mounted on the work machine
1 to the control apparatus 60. As described above, the
sensor 70 includes the position sensor 71 that detects the
position of the work machine 1, the vehicle attitude sensor
72 that detects the attitude of the swinging platform 3,
the working equipment attitude sensor 73 that detects the
attitude of the working equipment 4, and the pressure
sensor 74 that detects the pressure of the hydraulic oil in
the hydraulic cylinder 5.
[0098] The communication device 7 communicates with the
communication device 6 via the communication system 400.
The communication device 7 receives the operation signal of
the remote controller 40 transmitted from the control
apparatus 60 via the communication device 6, and outputs
the operation signal to the control apparatus 300. The
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28
communication device 7 transmits the image P in the imaging
range M received from the image data transmission unit 305
to the communication device 6 in the remote place. The
communication device 7 includes an encoder that compresses
image data of the image P. The image P is transmitted from
the communication device 7 to the communication device 6 in
a compressed state. The communication device 7 transmits
the detection data of the position sensor 71, the detection
data of the vehicle attitude sensor 72, the detection data
of the working equipment attitude sensor 73, and the
detection data of the pressure sensor 74 received from the
sensor data transmission unit 306 to the communication
device 6 in the remote place.
[0099] The communication device 6 communicates with the
communication device 7 via the communication system 400.
The communication device 6 transmits the operation signal
generated by operating the remote controller 40 to the
communication device 7. The communication device 6
receives the image P transmitted from the control apparatus
300 via the communication device 7, and outputs the image P
to the control apparatus 60. The communication device 6
includes a decoder that restores the image data of the
image P compressed. The image P is output from the
communication device 6 to the control apparatus 60 in a
restored state. The communication device 6 receives the
detection data of the position sensor 71, the detection
data of the vehicle attitude sensor 72, the detection data
of the working equipment attitude sensor 73, and the
detection data of the pressure sensor 74 transmitted from
the control apparatus 300 via the communication device 7,
and outputs them to the control apparatus 60.
[0100] The control apparatus 60 includes an operation
signal transmission unit 61, an image data reception unit
, CA 01182563 2022-11-04
29
62, a sensor data reception unit 63, an image processing
unit 64, a display control unit 65, and an alarm control
unit 66.
[0101] The operation signal transmission unit 61
transmits an operation signal for performing the remote
control of the work machine 1. When the remote controller
40 is operated by the operator, the operation signal for
performing the remote control of the work machine 1 is
generated. The operation signal transmission unit 61
transmits the operation signal of the remote controller 40
to the control apparatus 300.
[0102] The image data reception unit 62 receives the
image around the work machine 1. The image data reception
unit 62 receives the image P as the image around the work
machine 1. The image data reception unit 62 acquires the
image P restored by the decoder of the communication device
6.
[0103] The sensor data reception unit 63 receives the
detection data of the sensor 70. The detection data of the
sensor 70 includes detection data related to the swinging
platform 3 and detection data related to the working
equipment 4. The sensor data reception unit 63 receives
detection data of the position of the work machine 1
detected by the position sensor 71, detection data of the
attitude of the swinging platform 3 detected by the vehicle
attitude sensor 72, detection data of the attitude of the
working equipment 4 detected by the working equipment
attitude sensor 73, and detection data of the pressure of
the hydraulic oil in the hydraulic cylinder 5 detected by
the pressure sensor 74.
[0104] The image processing unit 64 divides the image P
received by the image data reception unit 62.
[0105] FIG. 8 is a diagram illustrating a process by the
, CA 01182563 2022-11-04
image processing unit 64 according to the embodiment. As
illustrated in FIG. 8, the image P is acquired by the image
data reception unit 62. The image P is an image of a front
space SP of the swinging platform 3. A part of the working
5 equipment 4 including the bucket 4C is captured in the
image P. The work target in front of the swinging platform
3 is also captured in the image P. Still more, the
handrail 3E of the upper deck 3D is captured in the image
P.
10 [0106] The image processing unit 64 divides the image P
into a plurality of images. The image processing unit 64
divides the image P into an image Pll to be displayed on
the central display 51, an image P12 to be displayed on the
left display 52, an image P13 to be displayed on the right
15 display 53, an image P14 to be displayed on the upper
display 54, and an image P15 to be displayed on the lower
display 55.
[0107] The display control unit 65 causes the display
apparatus 50 to display the image around the work machine
20 1. The display control unit 65 causes the display
apparatus 50 to display the image P as the image around the
work machine 1.
[0108] FIG. 9 is a diagram illustrating a process by the
display control unit 65 according to the embodiment. As
25 illustrated in FIG. 9, the display control unit 65 causes
the central display 51 to display the image Pll that is a
part of the image P. The display control unit 65 causes
the left display 52 to display the image P12 that is a part
of the image P. The display control unit 65 causes the
30 right display 53 to display the image P13 that is a part of
the image P. The display control unit 65 causes the upper
display 54 to display the image P14 that is a part of the
image P. The display control unit 65 causes the lower
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=
31
display 55 to display the image 215 that is a part of image
P.
[0109] In the embodiment, the display control unit 65
causes the display apparatus 50 to display a vehicle data
image P3 indicating the attitude of the swinging platform
3, a working equipment data image P4 indicating the
attitude of the working equipment 4, a load data image P5
indicating a weight of the cargo to be loaded onto the dump
truck, and a bucket data image P6 indicating the position
of the tip blade 4D of the bucket 4C.
[0110] The display control unit 65 calculates the
inclination angle of the swinging platform 3 with respect
to the horizontal plane based on the detection data of the
vehicle attitude sensor 72. The display control unit 65
causes the display apparatus 50 to display a symbol image
indicating the inclination angle of the swinging platform 3
as the vehicle data image P3. In the embodiment, the
vehicle data image P3 is displayed on the upper display 54.
[0111] In addition, the display control unit 65
calculates the attitude of the working equipment 4 based on
the detection data of the working equipment attitude sensor
73. The display control unit 65 causes the display
apparatus 50 to display an animation image indicating the
attitude of the working equipment 4 as the working
equipment data image P4. In the embodiment, the working
equipment data image P4 is displayed on the right display
53.
[0112] In addition, the display control unit 65
calculates the weight of the cargo to be loaded onto the
dump truck based on the detection data of a weight sensor
(not illustrated) that detects the weight of the cargo held
by the bucket 4C. The display control unit 65 causes the
display apparatus 50 to display an indicator image
. CA 01182563 2022-11-04
32
indicating the weight of the cargo as the load data image
P5. In the embodiment, the load data image P5 is displayed
on the right display 53. Note that the weight sensor that
detects the weight of the cargo loaded on the dump truck
may be provided on the dump truck, and detection data of
the weight sensor may be transmitted to the control
apparatus 60.
[0113] In addition, the display control unit 65
calculates the position of the tip blade 4D of the bucket
4C in the top-bottom direction based on the detection data
of the working equipment attitude sensor 73. The display
control unit 65 causes the display apparatus 50 to display
an indicator image indicating the position in the top-
bottom direction of the tip blade 4D of the bucket 4C as
the bucket data image P6. The position in the top-bottom
direction of the tip blade 4D is a height position from
ground GR. In the embodiment, the bucket data image P6 is
displayed on the right display 53.
[0114] The alarm control unit 66 outputs an alarm
control signal when determining that the working equipment
4 approaches the end position in the movable range of the
working equipment 4 based on the detection data of the
attitude of the working equipment 4 detected by the working
equipment attitude sensor 73. In other words, the alarm
control unit 66 outputs the alarm control signal when
determining that the piston of the hydraulic cylinder 5
approaches the stroke end and the working equipment 4 is
approaching the end position in the movable range.
[0115] The alarm control unit 66 outputs the alarm
control signal when determining that the working equipment
4 is operated to approach the end position in the alarm
zone based on the detection data of the attitude of the
working equipment 4 detected by the working equipment
, CA 01182563 2022-11-04
33
attitude sensor 73. In the embodiment, the alarm control
unit 66 starts outputting the alarm control signal when
determining that the working equipment 4 has moved from the
intermediate zone to the alarm zone.
[0116] As described above, the cushion control starts
when the working equipment 4 moves from the alarm zone to
the end zone. In the embodiment, when determining that the
working equipment 4 has moved from the intermediate zone to
the alarm zone, the alarm control unit 66 starts outputting
the alarm control signal before the cushion control starts.
[0117] The alarm control unit 66 outputs the alarm
control signal when determining that the working equipment
4 is operated to approach the end position in the end zone
based on the detection data of the attitude of the working
equipment 4 detected by the working equipment attitude
sensor 73. In the embodiment, the alarm control unit 66
continues to output the alarm control signal when
determining that the working equipment 4 is moving toward
the end position in each of the alarm zone and the end
zone. When the stroke end determination unit 304
determines that the working equipment 4 has moved from the
alarm zone to the end zone, the working equipment control
unit 303 starts the cushion control.
[0118] In addition, the alarm control unit 66 outputs
the alarm control signal when determining that the working
equipment 4 has reached the end position based on the
detection data of the attitude of the working equipment 4
detected by the working equipment attitude sensor 73. In
other words, in the embodiment, the alarm control unit 66
outputs the alarm control signal when the working equipment
4 moves toward the end position in each of the alarm zone
and the end zone, and when the working equipment 4 reaches
the end position.
, CA 01182563 2022-11-04
,
,
34
[0119] FIG. 10 is a diagram illustrating a process by
the alarm control unit 66 according to the embodiment. In
the embodiment, the alarm control unit 66 outputs the alarm
control signal to the display apparatus 50. The display
apparatus 50 is provided in the remote place from the work
machine 1, and outputs an alarm based on the alarm control
signal from the alarm control unit 66. In the embodiment,
the display apparatus 50 functions as an alarm device. As
illustrated in FIG. 10, when the hydraulic cylinder 5
approaches the stroke end and the working equipment 4 is
operated to approach the end position, the alarm control
unit 66 blinks the working equipment data image P4 as the
alarm. The alarm control unit 66 may blink the entire
working equipment data image P4 or may blink a background
image of the working equipment data image P4. The alarm
control unit 66 may change a color of the working equipment
4 displayed on the display apparatus 50 or blink the image
of the working equipment 4 as the alarm. The color of the
working equipment 4 may be changed by changing the color of
the entire working equipment 4 or by changing the color of
a part of the working equipment 4. For example, when the
arm 4B is close to the end position, the alarm control unit
66 may change the color of the arm 43. The blinking of the
image of the working equipment 4 may be blinking of the
entire image of the working equipment 4 or blinking of a
part of the image of the working equipment 4. For example,
when the arm 4B is close to the end position, the alarm
control unit 66 may blink the image of the arm 4B.
[0120] Note that the alarm control unit 66 may cause the
display apparatus 50 to display computer graphics (CG) as
the alarm. For example, when the bucket 4C is close to the
end position, the alarm control unit 66 may cause the
display apparatus 50 to superimpose computer graphics
, CA 01182563 2022-11-04
indicating the position and attitude of the bucket 4C on
the image P in the display.
[0121] <Remote control method>
FIG. 11 is a flowchart illustrating a remote control
5 method of the work machine 1 according to the embodiment.
[0122] When the remote controller 40 is operated, the
operation signal for performing the remote control of the
work machine 1 is transmitted from the operation signal
transmission unit 61 of the control apparatus 60 to the
10 control apparatus 300 (Step SB1).
[0123] The imaging apparatus 30 captures an image in the
imaging range M. The image data transmission unit 305
transmits the image P to the control apparatus 60 via the
communication device 7 and the communication system 400
15 (Step SA1).
[0124] The working equipment attitude sensor 73 detects
the attitude of the working equipment 4. The sensor data
transmission unit 306 transmits the detection data of the
attitude of the working equipment 4 detected by the working
20 equipment attitude sensor 73 to the control apparatus 60
via the communication device 7 and the communication system
400 (Step SA2).
[0125] In the embodiment, the sensor data transmission
unit 306 transmits not only the detection data of the
25 working equipment attitude sensor 73 but also the detection
data of the position sensor 71, the detection data of the
vehicle attitude sensor 72, and the detection data of the
pressure sensor 74 to the control apparatus 60 via the
communication device 7 and the communication system 400.
30 [0126] Note that the process in Step SA2 may be
performed before the process in Step SA1, or the process in
Step SA1 and the process in Step SA2 may be performed in
parallel.
, CA 01182563 2022-11-04
36
[0127] The image data reception unit 62 receives the
image P transmitted from the work machine 1 via the
communication device 6.
[0128] The image processing unit 64 divides the image P
into the image P11, the image P12, an image P13, the image
P14, and the image P15 (Step SB2).
[0129] The display control unit 65 causes the display
apparatus 50 to display the image P (Step SB3).
[0130] The stroke end determination unit 304 determines
whether the working equipment 4 is approaching the end
position in the end zone of the movable range based on the
detection data of the working equipment attitude sensor 73
(Step SA3).
[0131] When it is determined in Step SA3 that the
working equipment 4 is moving away from the end position in
the end zone, or when it is determined that the working
equipment 4 is not arranged in the end zone (Step SA3: No),
the control apparatus 300 returns to the process in Step
SAl.
[0132] When it is determined in Step SA3 that the
working equipment 4 is operated to approach the end
position in the end zone (Step SA3: Yes), the working
equipment control unit 303 performs the cushion control
(Step SA4).
[0133] More specifically, the working equipment control
unit 303 outputs, to the flow rate control valve 23, the
control command for reducing the flow rate of the hydraulic
oil supplied to the hydraulic cylinder 5. As a result, the
speed of the working equipment 4 operated to approach the
end position in the end zone decreases.
[0134] The alarm control unit 66 determines whether the
working equipment 4 is approaching the end position in the
alarm zone of the movable range based on the detection data
, CA 01182563 2022-11-04
37
of the working equipment attitude sensor 73 (Step SB4).
[0135] In Step SB4, when it is determined that the
working equipment 4 is moving away from the end position in
the alarm zone, or when it is determined that the working
equipment 4 is not arranged in each of the alarm zone and
the end zone (Step SB4: No), the control apparatus 60
returns to the process in Step SB1.
[0136] In Step S34, when it is determined that the
working equipment 4 is operated to approach the end
position in the alarm zone (Step SB4: Yes), the alarm
control unit 66 outputs the alarm control signal (Step
SB5).
[0137] Note that the determination in Step SA3 may be
performed by the control apparatus 60 in the remote control
room 200. The determination in Step SB4 may be performed
by the control apparatus 300 of the work machine 1.
[0138] As described with reference to FIG. 10, the alarm
control unit 66 causes the display apparatus 50 to output
the alarm. The operator in the remote place can recognize
that the working equipment 4 is operated to approach the
end position by looking at the alarm output from the
display apparatus 50.
[0139] In the present embodiment, in order to simplify
the description, the movable range of the working equipment
4 is determined based on the movable range of the rod of
the hydraulic cylinder 5. In other words, the end position
in the movable range of the working equipment 4 is defined
based on the stroke end of the hydraulic cylinder 5, and
when the hydraulic cylinder 5 reaches the stroke end, the
working equipment 4 is determined to reach the end position
in the movable range. However, based on relative angles of
the working equipment components including the boom 4A, the
arm 4B, and the bucket 4C, the working equipment components
. CA 01182563 2022-11-04
38
may reach the end position in the movable range, due to
mechanical restriction of the working equipment 4, before
the hydraulic cylinder 5 reaches the stroke end. In this
case, the end positions of the working equipment components
may be set based on a mechanical structure of the working
equipment 4. Still more, the end zone and the alarm zone
may be set based on the mechanical structure of the working
equipment 4. For example, when a relative angle of a first
working equipment component (e.g., boom 4A) and a second
working equipment component (e.g., arm 43) and a
correlation of a third working equipment component (e.g.,
bucket 40) with the end position (correlation data such as
map data or a relational expression) are obtained in
advance, the stroke end determination unit 304 can
determine whether or not the third working equipment
component is approaching the end position in the movable
range based on the detection data of the working equipment
attitude sensor 73 and the correlation obtained in advance.
[0140] <Computer System>
FIG. 12 is a block diagram illustrating a computer
system 1000 according to the embodiment. Each of the
control apparatus 60 and the control apparatus 300
described above includes the computer system 1000. The
computer system 1000 includes a processor 1001 such as a
central processing unit (CPU), a main memory 1002 including
a nonvolatile memory such as a read only memory (ROM) and a
volatile memory such as a random access memory (RAM), a
storage 1003, and an interface 1004 including an
input/output circuit. The function of the control
apparatus 60 and the function of the control apparatus 300
described above are stored in the storage 1003 as a
computer program. The processor 1001 reads the computer
program from the storage 1003, develops the computer
, CA 01182563 2022-11-04
39
program in the main memory 1002, and executes the above-
described processes according to the program. Note that
the computer program may be distributed to the computer
system 1000 via a network.
[0141] The computer program or the computer system 1000
arranged in the remote place can execute receiving the
detection data of the attitude of the working equipment 4
and outputting the alarm control signal to the alarm device
when determining that the working equipment 4 approaches or
reaches the end position in the movable range based on the
detection data according to the above-described embodiment.
[0142] <Effects>
As described above, according to the embodiment, the
work machine 1 includes the communication device 6 that
transmits the detection data of the working equipment
attitude sensor 73 to the remote place. As a result, the
operator in the remote place can recognize that an impact
may act on the working equipment 4 based on the detection
data of the working equipment attitude sensor 73.
[0143] For example, in a case where the cushion control
is not performed, when the rod of the hydraulic cylinder 5
reaches the stroke end and the working equipment 4 reaches
the end position in the movable range, the impact may act
on the working equipment 4. When the operator actually
boards the work machine 1, it is possible to feel that the
impact acting on the working equipment 4. On the other
hand, when the operator is in the remote place, it is not
possible to feel the impact acting on the working equipment
4. Therefore, there is a possibility that the operator in
the remote place further performs the remote control in
which an excessive impact acts on the working equipment 4.
When the excessive impact acts on the working equipment 4,
deterioration of the working equipment 4 may be
, CA 01182563 2022-11-04
accelerated. In addition, even in a case where the cushion
control is performed, when the working equipment 4 reaches
the end position many times, the working equipment 4 may
deteriorate.
5 [0144] In the embodiment, the detection data of the
working equipment attitude sensor 73 is transmitted from
the work machine 1 to the remote place. When it is
determined that the working equipment 4 is operated to
approach the end position in the movable range based on the
10 detection data of the working equipment attitude sensor 73,
the alarm is output in the remote place. As a result, the
operator in the remote place can recognize that the working
equipment 4 is approaching the end position. Therefore,
the operator in the remote place can perform the remote
15 control to avoid applying the excessive impact to the
working equipment 4. For example, the operator in the
remote place can operate the remote controller 40 such that
the working equipment 4 does not reach the end position.
[0145] In the embodiment, the cushion control is
20 performed when the working equipment 4 moves from the alarm
zone to the end zone. As a result, the impact acting on
the working equipment 4 is reduced. In addition, there is
a possibility that the working equipment 4 reaches the end
position against the intention of the operator in the
25 remote place due to a communication delay of the image data
acquired by the imaging apparatus 30. The possibility that
the communication delay of image data acquired by the
imaging apparatus 30 occurs is higher than a possibility
that a communication delay of the operation signal of the
30 remote controller 40 occurs. Even when the operator in the
remote place operates the remote controller 40 to cause the
working equipment 4 stop immediately before the end
position, while viewing the image displayed on the display
CA 01182563 2022-11-04
41
apparatus 50, there is a possibility that the working
equipment 4 reaches the end position against the intention
of the operator in the remote place due to the
communication delay of the image data. According to the
embodiment, the cushion control is performed based on the
detection data of the working equipment attitude sensor 73.
As a result, even when the communication delay of the image
data occurs, an impact on the working equipment 4 is
suppressed.
[0146] In the embodiment, when the working equipment 4
moves from the intermediate zone to the alarm zone, the
alarm control unit 66 starts to output the alarm control
signal, and the display apparatus 50 starts to output the
alarm. In other words, the display apparatus 50 starts to
output the alarm before the cushion control of the working
equipment 4 is performed. As a result, the operator in the
remote place can more reliably perform the remote control
that does not cause the excessive impact to be applied to
the working equipment 4.
[0147] Still more, even after the working equipment 4
moves from the alarm zone to the end zone, the alarm
control unit 66 continues to output the alarm control
signal, and thus the display apparatus 50 continues to
output the alarm. As a result, the operator in the remote
place can recognize that the working equipment 4 is
approaching the end position in the end zone.
[0148] Furthermore, according to the embodiment, even
after the working equipment 4 reaches the end position, the
alarm control unit 66 continues to output the alarm control
signal, and thus the display apparatus 50 continues to
output the alarm. As a result, the operator in the remote
place can recognize that the working equipment 4 has
reached the end position.
, CA 01182563 2022-11-04
42
[0149] <Other embodiments>
In the embodiment described above, the stroke end
determination unit 304 determines whether the working
equipment 4 exists in the end zone of the movable range
based on the detection data of the working equipment
attitude sensor 73. The stroke end determination unit 304
may determine whether the working equipment 4 exists in the
end zone of the movable range based on an output of a
proximity switch. The proximity switch is a switch that
operates when the working equipment 4 moves to the end
position in the movable range.
[0150) Note that, in the above-described embodiment, the
alarm control unit 66 causes the display apparatus 50 to
output the alarm. For example, the alarm control unit 66
may cause at least a part of the first monitor device 501,
the second monitor device 503, and the third monitor device
504 to output the alarm. In a case where the alarm is
output by at least a part of the display apparatus 50, the
first monitor device 501, the second monitor device 503,
and the third monitor device 504, an alarm message such as
"pay attention to lever operation" or "approaching stroke
end" may be displayed. When a sound output device or a
buzzer is arranged in the remote control room 200, the
alarm control unit 66 may cause the sound output device or
the buzzer to output an alarm sound as the alarm. When a
vibration generator is disposed on the operating seat 45,
the alarm control unit 66 may vibrate the operating seat 45
as the alarm. In other words, the alarm device may not be
the display apparatus 50, and may be at least one of the
first monitor device 501, the second monitor device 503,
the third monitor device 504, the sound output device, the
buzzer, and the vibration generator.
[0151] In the above-described embodiment, the alarm
, CA 01182563 2022-11-04
43
control unit 66 outputs the alarm before the working
equipment 4 reaches the end position. However, the alarm
control unit 66 may output the alarm when determining that
the working equipment 4 has reached the end position in the
movable range based on the detection data of the working
equipment attitude sensor 73. In other words, the alarm
control unit 66 may output the alarm after the working
equipment 4 that is operated to approach the end position
has reached the end position. As a result, the operator in
the remote place can recognize, based on the alarm, that
the working equipment 4 has reached the end position and
that there is a possibility that an impact has acted on the
working equipment 4. The computer program or the computer
system 1000 arranged in the remote place described with
reference to FIG. 12 can execute receiving the detection
data of the attitude of the working equipment 4 and
outputting the alarm when it is determined that the working
equipment 4 has reached the end position in the movable
range based on the detection data.
[0152] In the above embodiment, the output of the alarm
may be omitted. The cushion control may be performed in a
state that no alarm is output.
[0153] In the above-described embodiment, the cushion
control may not be performed. For example, when the
operator slowly operates the remote controller 40, the
impact acting on the working equipment 4 is small. When
the cylinder speed of the rod is equal to or lower than a
speed threshold, the cushion control may not be performed.
[0154] [Second embodiment]
A second embodiment will be described. In the
following description, the same or equivalent components as
those of the above-described embodiment are denoted by the
same reference signs, and the description thereof is
, CA 01182563 2022-11-04
44
simplified or omitted.
[0155] FIG. 13 is a diagram illustrating the operation
of the work machine 1 according to the embodiment. As
illustrated in FIG. 13, when the work machine 1 causes the
working equipment 4 to collide with the work target, an
impact may act on the working equipment 4. For example,
there is a possibility that an impact acts on the working
equipment 4 when the working equipment 4 excavates the work
target or when the work machine 1 lowers the working
equipment 4 to the work target. In addition, when the
cushion control is not performed, there is a possibility
that an impact acts on the working equipment 4 by the
working equipment 4 reaching the end position.
[0156] In the embodiment, the alarm control unit 66
outputs the alarm control signal in a case where it is
determined that a level of the impact acting on the working
equipment 4 is equal to or greater than a threshold based
on the detection data related to the working equipment 4
received by the sensor data reception unit 63. The
threshold related to the level of impact is a predetermined
value and is held in the alarm control unit 66.
[0157] When an impact acts on the working equipment 4,
the working equipment 4 vibrates with an amplitude of a
predetermined value or higher. In other words, when the
impact acts on the working equipment 4, the attitude of the
working equipment 4 changes such that the working equipment
4 reciprocates at the amplitude equal to or larger than a
first threshold. The alarm control unit 66 can determine
whether the level of the impact is equal to or greater than
the threshold based on the detection data of the attitude
of the working equipment 4 detected by the working
equipment attitude sensor 73.
[0158] Still more, when an impact acts on the working
, CA 01182563 2022-11-04
equipment 4, a pressure of the hydraulic oil in the
hydraulic cylinder 5 rapidly changes. More specifically,
when the impact acts on the working equipment 4, the
pressure of the hydraulic oil in the hydraulic cylinder 5
5 increases by a change amount equal to or greater than a
second threshold. The alarm control unit 66 can determine
whether the level of the impact is equal to or greater than
the threshold based on the detection data of the pressure
of the hydraulic oil detected by the pressure sensor 74.
10 [0159] Still more, when an impact acts on the working
equipment 4, the swinging platform 3 vibrates in a pitch
direction with an amplitude or acceleration equal to or
greater than a predetermined value. The alarm control unit
66 can determine whether the level of the impact is equal
15 to or greater than the threshold based on the detection
data of the vehicle attitude sensor 72 including the
inertial measurement unit (IMU) provided in the swinging
platform 3.
[0160] Still more, when an impact acts on the working
20 equipment 4, the working equipment 4 vibrates at an
acceleration equal to or greater than a predetermined
value. When the acceleration sensor is disposed in the
working equipment 4, the alarm control unit 66 can
determine whether the level of the impact is equal to or
25 greater than the threshold based on the detection data of
the acceleration sensor.
[0161] FIG. 14 is a flowchart illustrating a remote
control method of the work machine 1 according to the
embodiment. In an example illustrated in FIG. 14, it is
30 assumed that the alarm control unit 66 determines whether
the level of the impact is equal to or greater than the
threshold based on the detection data of the pressure of
the hydraulic oil detected by the pressure sensor 74. As
, CA 01182563 2022-11-04
46
described above, the alarm control unit 66 can determine
whether the level of the impact is equal to or greater than
the threshold based on at least one of the detection data
of the working equipment attitude sensor 73, the detection
data of the vehicle attitude sensor 72, and the detection
data of the acceleration sensor.
[0162] When the remote controller 40 is operated, the
operation signal for performing the remote control of the
work machine 1 is transmitted from the operation signal
transmission unit 61 of the control apparatus 60 to the
control apparatus 300 (Step SB11).
[0163] The image P is transmitted from the work machine
1 to the control apparatus 60 (Step SA11).
[0164] The detection data of the sensor 70 is
transmitted from the work machine 1 to the control
apparatus 60. In the embodiment, the sensor data
transmission unit 306 transmits at least the detection data
of the pressure of the hydraulic oil in the hydraulic
cylinder 5 detected by the pressure sensor 74 to the
control apparatus 60 via the communication device 7 and the
communication system 400 (Step SA12).
[0165] Note that the process in Step SA12 may be
performed before the process in Step SAll, or the process
in Step SAll and the process in Step SA12 may be performed
in parallel.
[0166] The image data reception unit 62 receives the
image P transmitted from the work machine 1 via the
communication device 6. Image processing unit 64 divides
the image P into the image Pll, the image P12, the image
P13, the image P14, and the image P15 (Step 5B12).
[0167] The display control unit 65 causes the display
apparatus 50 to display the image P (Step SB13).
[0168] The alarm control unit 66 determines whether the
CA 01182563 2022-11-04
47
level of the impact acting on the working equipment 4 is
equal to or greater than the threshold based on the
detection data of the pressure sensor 74 (Step SB14).
[0169] In Step SB14, when it is determined that the
level of the impact acting on the working equipment 4 is
less than the threshold (Step SB14: No), the control
apparatus 60 returns to the process in Step SB12.
[0170] In Step S314, when it is determined that the
level of the impact acting on the working equipment 4 is
equal to or greater than the threshold value (Step SB14:
Yes), the alarm control unit 66 outputs the alarm control
signal (Step S315).
[0171] Note that the determination in Step SB14 may be
performed by the control apparatus 300 of the work machine
1.
[0172] As described above, the computer program or the
computer system 1000 arranged in the remote place described
with reference to FIG. 12 can execute receiving the
detection data related to the working equipment 4 and
outputting the alarm control signal to the alarm device in
a case where it is determined that the level of the impact
acting on the working equipment 4 is equal to or greater
than the threshold based on the detection data.
[0173] [Other embodiments]
In the above-described embodiment, the control
apparatus 60 of the remote control room 200 functions as
the alarm control unit 66. However, the control apparatus
300 of the work machine 1 may function as the alarm control
unit 66. The alarm control signal output from the alarm
control unit 66 provided in the work machine 1 may be
transmitted to the remote control room 200 via the
communication system 400, and the alarm device provided in
the remote control room 200 may output the alarm based on
, CA 01182563 2022-11-04
=
48
the alarm control signal from the alarm control unit 66.
[0174] In the embodiment described above, the work
machine 1 is a loading excavator. However, the work
machine 1 may be a backhoe. Still more, the work machine 1
may be a bulldozer or a wheel loader as long as the work
machine is equipped with the working equipment.
Reference Signs List
[0175] 1 WORK MACHINE
2 TRAVELING BODY
2A DRIVE WHEEL
2B DRIVEN WHEEL
2C CRAWLER
3 SWINGING PLATFORM
3A CAB
3B LOWER DECK
3C STEP
3D UPPER DECK
3E HANDRAIL
3F LADDER
4 WORKING EQUIPMENT
4A BOOM
4B ARM
4C BUCKET
4D TIP BLADE
5 HYDRAULIC CYLINDER
5A BOOM CYLINDER
5B ARM CYLINDER
5C BUCKET CYLINDER
6 COMMUNICATION DEVICE
7 COMMUNICATION DEVICE
20 HYDRAULIC SYSTEM
21 HYDRAULIC PUMP
22 PUMP FLOW PATH
, CA 01182563 2022-11-04
,
,
49
23 FLOW CONTROL VALVE
23A BOOM FLOW RATE CONTROL VALVE
23B ARM FLOW RATE CONTROL VALVE
23C BUCKET FLOW RATE CONTROL VALVE
24 SUPPLY FLOW PATH
25 BOTTOM FLOW PATH
26 ROD FLOW PATH
27 DISCHARGE FLOW PATH
28 TANK
30 IMAGING APPARATUS
40 REMOTE CONTROLLER
41 LEFT WORKING LEVER
42 RIGHT WORKING LEVER
43 LEFT TRAVEL PEDAL
44 RIGHT TRAVEL PEDAL
45 OPERATING SEAT
50 DISPLAY APPARATUS
51 CENTER DISPLAY
52 LEFT DISPLAY
53 RIGHT DISPLAY
54 UPPER DISPLAY
55 LOWER DISPLAY
60 CONTROL APPARATUS
61 OPERATION SIGNAL TRANSMISSION UNIT
62 IMAGE DATA RECEPTION UNIT
63 SENSOR DATA RECEPTION UNIT
64 IMAGE PROCESSING UNIT
65 DISPLAY CONTROL UNIT
66 ALARM CONTROL UNIT
70 SENSOR
71 POSITION SENSOR
72 VEHICLE ATTITUDE SENSOR
73 WORKING EQUIPMENT ATTITUDE SENSOR
, CA 01182563 2022-11-04
,
=
73A BOOM ATTITUDE SENSOR
73B ARM ATTITUDE SENSOR
73C BUCKET ATTITUDE SENSOR
74 PRESSURE SENSOR
5 74A BOOM PRESSURE SENSOR
74B ARM PRESSURE SENSOR
74C BUCKET PRESSURE SENSOR
100 REMOTE CONTROL SYSTEM
200 REMOTE CONTROL ROOM
10 300 CONTROL APPARATUS
301 TRAVELING BODY CONTROL UNIT
302 SWINGING PLATFORM CONTROL UNIT
303 WORKING EQUIPMENT CONTROL UNIT
304 STROKE END DETERMINATION UNIT
15 305 IMAGE DATA TRANSMISSION UNIT
306 SENSOR DATA TRANSMISSION UNIT
400 COMMUNICATION SYSTEM
501 FIRST MONITOR DEVICE
502 OPERATION SWITCH
20 503 SECOND MONITOR DEVICE
504 THIRD MONITOR DEVICE
1000 COMPUTER SYSTEM
1001 PROCESSOR
1002 MAIN MEMORY
25 1003 STORAGE
1004 INTERFACE
AX BOOM ROTATION AXIS
BR BOTTOM CHAMBER
BX ARM ROTATION AXIS
30 CX BUCKET ROTATION AXIS
GR GROUND
RR ROD CHAMBER
RX SWING AXIS
CA 03182563 2022-11-04
51
M IMAGING RANGE
OA OPTICAL AXIS
P IMAGE
Pll IMAGE
P12 IMAGE
P13 IMAGE
P14 IMAGE
P15 IMAGE
P3 VEHICLE DATA IMAGE
P4 WORKING EQUIPMENT DATA IMAGE
P5 LOAD DATA IMAGE
P6 BUCKET DATA IMAGE
Pa PUMP PORT
Pb BOTTOM PORT
Pc ROD PORT
Pd TANK PORT
Q1 FIRST OPERATING POSITION
Q2 SECOND OPERATING POSITION
Q3 STOP POSITION
