CA3214459A1

CA3214459A1 - System and method for controlling work machine

Info

Publication number: CA3214459A1
Application number: CA3214459A
Authority: CA
Inventors: Kei NAKANO; Souichi Tsumura
Original assignee: Komatsu Ltd
Current assignee: Komatsu Ltd
Priority date: 2021-06-25
Filing date: 2022-04-18
Publication date: 2022-12-29
Also published as: AU2022297925A1; WO2022270136A1; JP2023004406A; US20240159016A1

Abstract

This system is provided with: an on-vehicle controller; a remote control device; and a communication machine. The on-vehicle controller is mounted on a work machine, and controls the work machine. The remote control device communicates with the on-vehicle controller. The remote control device transmits, to the work machine, a start instruction signal for stating the work machine. The communication machine is provided to a body separated from the remote control device. The communication machine communicates with the on-vehicle controller. The communication machine can be operated so as to switch the work machine from a start-prohibited state to a start-permitted state. The on-vehicle controller switches the work machine from the start-prohibited state to the start-permitted state in response to an operation on the communication machine. When the work machine is in the start-prohibited state, the on-vehicle controller prohibits the work machine from starting even if the start instruction signal is received from the remote control device. When the work machine is in the start-permitted state, the on-vehicle controller causes the work machine to start if the start instruction signal is received from the remote control device.

Description

SYSTEM AND METHOD FOR CONTROLLING WORK MACHINE
TECHNICAL FIELD
[0001] The present invention relates to a system and a method for controlling a work machine.
BACKGROUND ART

[0002] Some work machines can be started by a remote operation. For example, a construction machine vehicle in Patent Document 1 checks whether a predetermined condition is satisfied upon receiving a command signal from a transmitter, and starts an engine if the predetermined condition is satisfied. The predetermined condition includes, for example, the fact that the engine is stopped, the fact that a shift lever is in a neutral position, the fact that a parking brake is in an operating position, the fact that a door for the driver's seat is closed, or the like.
CITATION LIST
PATENT DOCUMENT

[0003] Patent Document 1: Japanese Unexamined Patent Publication No. H08-SUMMARY OF THE INVENTION
Technical Problem

[0004] Conditions in which a work machine is started are varied and not always the same. For example, there is a case where a work machine is started in order to start normal work at a work site or a case where maintenance work or troubleshooting is performed on the work machine. However, it is not easy to accurately understand a condition in which the work machine is started from a remote place.

[0005] For example, in a case where the work machine is remotely controlled at a management center that is far away from the work machine, it is difficult to accurately Date Recue/Date Received 2023-09-21 understand a condition of the work machine since the work machine and its surroundings cannot be visually observed. In addition, determining whether to start the engine based only on a predetermined condition as described above is not always suitable for the condition of the work machine. An object of the present disclosure is to start a work machine to be started by a remote operation at an appropriate timing according to a condition of the work machine.
SOLUTION TO PROBLEM

[0006] A
system according to one aspect of the present disclosure is a system for controlling a work machine. The system includes an onboard controller, a remote operation device, and a communication unit. The onboard controller is mounted on the work machine and controls the work machine. The remote operation device communicates with the onboard controller. The remote operation device transmits a start command signal for starting the work machine to the work machine. The communication unit is provided separately from the remote operation device. The communication unit communicates with the onboard controller. The communication unit is configured to be operated to switch the work machine from a start prohibited state to a start permitted state.

[0007] The onboard controller switches the work machine from the start prohibited state to the start permitted state according to an operation of the communication unit. The onboard controller prohibits the work machine from starting when the work machine is in the start prohibited state, even in a case where the start command signal has been received from the remote operation device. The onboard controller starts the work machine when the work machine is in the start permitted state, in a case where the start command signal has been received from the remote operation device.

[0008] A
method according to another aspect of the present disclosure is a method for controlling a work machine. The method includes communicating with a communication unit, switching the work machine from a start prohibited state to a start permitted state according to an operation of the communication unit, communicating with a remote Date Recue/Date Received 2023-09-21 operation device, determining whether a start command signal for the work machine has been received from the remote operation device, starting the work machine when the work machine is in the start permitted state in a case where the start command signal has been received from the remote operation device, and, prohibiting the work machine from starting when the work machine is in the start prohibited state even in a case where the start command signal has been received from the remote operation device.
ADVANTAGEOUS EFFECTS OF INVENTION

[0009] In the system and method according to the present disclosure, when an operator at a work site is performing work on the work machine, the work machine is prohibited from starting until the operator at the work site operates the communication unit to switch the work machine from the start prohibited state to the start permitted state.
Therefore, even if a remote operator operates the remote operation device to transmit the start command signal to the work machine, the work machine does not start.

[0010] The operator at the work site operates the communication unit to switch the work machine from the start prohibited state to the start permitted state after completing the work on the work machine. Accordingly, the remote operator operates the remote operation device to transmit the start command signal to the work machine, whereby the work machine starts. As a result, in the system and method according to the present disclosure, the work machine to be started by the remote operation can be started at an appropriate timing according to a condition of the work machine.
BRIEF DESCRIPTION OF DRAWINGS

[0011] FIG. 1 is a block diagram illustrating a configuration of a system for controlling a work machine according to an embodiment.
FIG. 2 is a perspective view of the work machine.
FIG. 3 is a flowchart illustrating processes for starting the work machine executed by an onboard controller.
Date Recue/Date Received 2023-09-21 DESCRIPTION OF EMBODIMENTS

[0012] A system for controlling a work machine according to an embodiment will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a system 1 according to the embodiment. The system 1 according to the present embodiment includes a work machine 2, a remote operation device 3, and a mobile communication unit 4. The work machine 2 is disposed at a work site such as a mine.
The work machine 2 is a bulldozer, for example.

[0013] FIG. 2 is a perspective view of the work machine 2. As illustrated in FIG. 2, the work machine 2 includes a body 10 and a work implement 13. The body 10 includes a vehicle body 11 and a travel device 12. The vehicle body 11 includes an operating cabin

14 and a power compartment 15. An operator's seat that is not illustrated is disposed in the operating cabin 14. The power compartment 15 is disposed in front of the operating cabin 14. The travel device 12 is attached to a lower portion of the vehicle body 11. The travel device 12 includes a pair of left and right crawler belts 16. Only the left crawler belt 16 is illustrated in FIG. 1. The work machine 2 travels due to the rotation of the crawler belts 16.
[0014] The work implement 13 is attached to the body 10. The work implement includes a lift frame 17, a blade 18 and a lift cylinder 19. The lift frame 17 is attached to the travel device 12 so as to be movable up and down. The lift frame 17 supports the blade 18. The blade 18 is disposed in front of the vehicle body 11. The lift cylinder 19 is coupled to the vehicle body 11. The front end of the lift cylinder 19 is rotatably attached to a back surface of the blade 18. The blade 18 moves up and down due to the extension and contraction of the lift cylinder 19.

[0015] As illustrated in FIG. 1, the work machine 2 includes a power source 21, a hydraulic pump 22, and a power transmission device 23. In the present embodiment, the power source 21 is an internal combustion engine. A starter motor 24 is connected to the power source 21. The starter motor 24 starts the power source 21. The hydraulic pump Date Recue/Date Received 2023-09-21 22 is driven by the power source 21 to discharge hydraulic fluid. The hydraulic fluid discharged from the hydraulic pump 22 is supplied to the lift cylinder 19.
Although one hydraulic pump is illustrated in FIG. 2, a plurality of hydraulic pumps may be provided.

[0016] The power transmission device 23 transmits driving force of the power source 21 to the travel device 12. The power transmission device 23 may be a hydro static transmission (HST), for example. Alternatively, the power transmission device 23 may be, for example, a transmission having a torque converter or a plurality of transmission gears.

[0017] The work machine 2 includes an onboard controller 25 and a control valve 26.
The onboard controller 25 is mounted on the work machine 2. The onboard controller 25 is implemented by a computer including a processor and a memory. The onboard controller 25 may be configured by a plurality of controllers separate from one another.
The onboard controller 25 is programmed to control the work machine 2 based on acquired data.

[0018] The control valve 26 is a proportional control valve and is controlled by a command signal from the onboard controller 25. The control valve 26 is disposed between the hydraulic pump 22 and a hydraulic actuator such as the lift cylinder 19. The control valve 26 controls the flow rate of the hydraulic fluid supplied from the hydraulic pump 22 to the lift cylinder 19. The onboard controller 25 controls the control valve 26 so that the work implement 13 is raised or lowered. The control valve 26 may be a pressure proportional control valve. Alternatively, the control valve 26 may be an electromagnetic proportional control valve.

[0019] The work machine 2 includes a camera 27, an onboard operating member 28, a first mode selection member 29, and a second mode selection member 30. The camera 27 is attached to the vehicle body 11, for example. The camera 27 acquires an image of the surroundings of the work machine 2. The camera 27 transmits an image signal indicative of the image of the surroundings of the work machine 2 to the onboard controller 25.
Date Recue/Date Received 2023-09-21

[0020] The onboard operating member 28 is disposed in the operating cabin 14. The onboard operating member 28 is configured to be operated by an operator to cause the work machine 2 to travel. Further, the onboard operating member 28 is configured to be operated by the operator to cause the work implement 13 to move. The onboard operating member 28 includes an operating lever, for example. The onboard operating member 28 may include another operating member such as a pedal, a switch, a touch screen, or the like.

[0021] The onboard operating member 28 transmits an operation signal indicative of an operation by the operator to the onboard controller 25. The onboard controller 25 controls the power source 21 and the power transmission device 23 according to the operation signal, thereby causing the work machine 2 to travel. The onboard controller 25 controls the hydraulic pump 22 and the control valve 26 according to the operation signal, thereby causing the work implement 13 to move.

[0022] The first mode selection member 29 is disposed in the operating cabin 14. The first mode selection member 29 is configured to be operated by the operator to set a control mode of the work machine 2. The first mode selection member 29 is, for example, a touch screen type input device. The first mode selection member 29 may be another input device such as a switch. The first mode selection member 29 transmits an input signal indicative of an operation by the operator to the onboard controller 25.

[0023] The control mode includes a direct operation mode and a remote operation mode. In the direct operation mode, the onboard controller 25 controls the work machine 2 according to the operation signal from the onboard operating member 28.
Therefore, in the direct operation mode, the operator operates the onboard operating member 28, thereby causing the work machine 2 to move. In the remote operation mode, the work machine 2 is controlled according to a remote control signal from the remote operation device 3.
Therefore, in the remote operation mode, the operator operates the remote operation device 3, thereby causing the work machine 2 to move.

[0024] The second mode selection member 30 is attached to the work machine 2. The Date Recue/Date Received 2023-09-21 second mode selection member 30 is configured to be operated by the operator to select the remote operation mode as the control mode for work machine 2. The second mode selection member 30 is a switch, for example. Alternatively, the second mode selection member 30 may be another member such as a lever, a touch screen, or the like.
The second mode selection member 30 is disposed on an outer surface of the work machine 2.
For example, the second mode selection member 30 is disposed at a position on the work machine 2 where an operator on the ground can operate. For example, the second mode selection member 30 may be disposed at a height of 2000 mm or less on a lower part of the rear portion of the vehicle body 11. The second mode selection member 30 transmits a selection signal indicative of an operation by the operator to the onboard controller 25.

[0025] The work machine 2 includes a first communication device 31 and a second communication device 32. The first communication device 31 and the second communication device 32 are mounted on the work machine 2. The first communication device 31 wirelessly communicates with the remote operation device 3. The second communication device 32 wirelessly communicates with the mobile communication unit 4.
The communication methods of the first communication device 31 and the second communication device 32 may be same or different from each other. The work machine 2 and the remote operation device 3 may communicate with each other directly or via a control system or the like.

[0026] The remote operation device 3 is disposed in a management center away from the work site. An operator in the management center can remotely operate the work machine 2 by operating the remote operation device 3. The remote operation device 3 includes a communication device 33, a remote operation member 34, a remote input device 35, a display 36 and a remote controller 37. The communication device 33 wirelessly communicates with the first communication device 31 of the work machine 2.

[0027] The remote operation member 34 is configured to be operated by the operator to cause the work machine 2 to travel in the same manner as the onboard operating member

28.
Further, the remote operation member 34 is configured to be operated by the operator Date Recue/Date Received 2023-09-21 to cause the work implement 13 to move in the same manner as the onboard operating member 28. The remote operation member 34 includes, for example, an operating lever.
The remote operation member 34 may include another operating member such as a pedal, a switch, a touch screen, or the like. The remote operation member 34 transmits an operation signal indicative of an operation by the operator to the remote controller 37.
[0028] The remote input device 35 is configured to be operated by the operator to input a setting of the work machine 2. The remote input device 35 is, for example, a touch screen type input device. The remote input device 35 may be another input device such as a switch. The remote input device 35 transmits an input signal indicative of an operation by the operator to the remote controller 37.

[0029] The remote controller 37 is implemented by a computer including a processor and a memory. The remote controller 37 may be configured by a plurality of controllers separate from one another. The remote controller 37 transmits a remote control signal to the onboard controller 25 via the communication device 33. The remote controller 37 generates the remote control signal based on the operation signal from the remote operation member 34 or the input signal from the remote input device 35.

[0030] The onboard controller 25 controls the power source 21 and the power transmission device 23 according to the remote control signal from the remote controller 37, thereby causing the work machine 2 to travel. The onboard controller 25 controls the hydraulic pump 22 and the control valve 26 according to the remote control signal from the remote controller 37, thereby causing the work implement 13 to move.

[0031] The onboard controller 25 transmits the image signal from the camera 27 to the remote controller 37. The remote controller 37 displays the image indicative of the surroundings of the work machine 2 on the display 36 based on the image signal. The operator can operate the work machine 2 by operating the remote operation member 34 while viewing the image indicative of the surroundings of the work machine 2 on the display 36.

[0032] The mobile communication unit 4 is provided separately from the remote Date Recue/Date Received 2023-09-21 operation device 3. The mobile communication unit 4 is configured to be operated by the operator. The mobile communication unit 4 includes a communication function in the same manner as the remote operation device 3. The mobile communication unit 4 wirelessly communicates with the onboard controller 25.
Specifically, the mobile communication unit 4 wirelessly communicates with the second communication device 32 of the work machine 2. Alternatively, the mobile communication unit 4 may wirelessly communicate with the first communication device 31 of the work machine 2.

[0033] The mobile communication unit 4 is portable. The mobile communication unit 4 is carried to the work site where the work machine 2 is disposed. The mobile communication unit 4 is operated by the operator at the work site. The mobile communication unit 4 wirelessly communicates with the onboard controller 25 at a shorter distance than the remote operation device 3. The operator operates the mobile communication unit 4 in a range where the work machine 2 can be visually observed.

[0034] The mobile communication unit 4 may be a general-purpose mobile communication terminal such as a laptop computer, a tablet computer, a smart phone, or the like. Alternatively, the mobile communication unit 4 may be a dedicated terminal of the system 1 for controlling the work machine 2. The mobile communication unit includes an operating member such as a switch, a lever, a touch screen, or the like.

[0035] The mobile communication unit 4 is configured to be operated to switch the work machine 2 from a start prohibited state to a start permitted state. The mobile communication unit 4 transmits a start permission signal to the onboard controller 25 according to an operation by the operator. The start permission signal is a signal for switching the work machine 2 from the start prohibited state to the start permitted state.
Processes for starting the work machine 2 will be described below.

[0036] FIG. 3 is a flowchart illustrating processes executed by the onboard controller 25 to start the work machine 2. When the work machine 2 being started, the onboard controller 25 is already activated due to the electric power supplied from a battery mounted on the work machine 1. As illustrated in FIG. 3, in step S101, the onboard controller 25 Date Recue/Date Received 2023-09-21 sets the work machine 2 in the start prohibited state. The onboard controller 25 sets the work machine 2 in the start prohibited state when the power source 21 is stopped and the start permission signal is not received from the mobile communication unit 4.
When the work machine 2 is in the start prohibited state, the power source 21 is prohibited from starting.

[0037] In step S102, the onboard controller 25 determines whether the control mode of the work machine 2 is the remote operation mode. The onboard controller 25 determines that the control mode of the work machine 2 is the remote operation mode when the remote operation mode is set by the first mode selection member 29 and the remote operation mode is selected by the second mode selection member 30. When the onboard controller 25 determines that the control mode of the work machine 2 is the remote operation mode, the process proceeds to step S103.

[0038] In step S103, the onboard controller 25 determines whether the start permission signal has been received from the mobile communication unit 4. The mobile communication unit 4 transmits the start permission signal to the onboard controller 25 according to the operation by the operator at the work site. When the onboard controller 25 determines that the start permission signal has been received from the mobile communication unit 4, the process proceeds to step S104.

[0039] In step S104, the onboard controller 25 releases the start prohibited state of the work machine 2. In a case where the start permission signal is not received from the mobile communication unit 4 in step S103, the onboard controller 25 maintains the work machine 2 in the start prohibited state.

[0040] In step S105, the onboard controller 25 determines whether a start command signal for starting the work machine 2 has been received. The start command signal is transmitted from the remote operation device 3. The remote operation device 3 transmits the start command signal to the onboard controller 25 according to an operation of the remote input device 35 by an operator in the management center (hereinafter referred to as a "remote operator"). When the onboard controller 25 receives the start command signal, Date Recue/Date Received 2023-09-21 the process proceeds to step S106.

[0041] In step S106, the onboard controller 25 determines whether the work machine 2 is in the start permitted state. The onboard controller 25 determines that the work machine 2 is in the start permitted state when the start prohibited state of the work machine 2 is released in step S104. Alternatively, the onboard controller 25 may determine that the work machine 2 is in the start permitted state when another start permission condition is satisfied in addition to that the start prohibited state of the work machine 2 is released.
When the onboard controller 25 determines that the work machine 2 is in the start permitted state, the process proceeds to step S107. In step S107, the onboard controller 25 starts the work machine 2. That is, the onboard controller 25 starts the power source 21 by driving the starter motor 24.

[0042] When the onboard controller 25 determines that the work machine 2 is not in the start permitted state in step S106, the onboard controller 25 does not start the work machine 2 even in a case where the start command signal has been received from the remote operation device 3. That is, when the work machine 2 is in the start prohibited state, the onboard controller 25 prohibits the work machine 2 from starting even in a case where the start command signal has been received from the remote operation device 3.

[0043] In the system 1 according to the present embodiment described above, the onboard controller 25 releases the start prohibited state of the work machine 2 when the start permission signal has been received from the mobile communication unit 4. Then, in a case where the start command signal has been received from the remote operation device 3, the onboard controller 25 starts the work machine 2 when the work machine 2 is in the start permitted state. However, when the work machine 2 is in the start prohibited state, the onboard controller 25 prohibits the work machine 2 from starting even in a case where the start command signal has been received from the remote operation device 3.

[0044] Therefore, when the operator at the work site is performing work on the work machine 2 such as maintenance work, troubleshooting, judging the suitability of safety around the work machine 2, or making preparations to ensure safety, the start of the work Date Recue/Date Received 2023-09-21 machine 2 is prohibited until the operator at the work site operates the mobile communication unit 4 to release the start prohibited state of the work machine 2.
Accordingly, even if the remote operator operates the remote operation device 3 to transmit the start command signal to the work machine 2, the work machine 2 does not start. As a result, the operator at the work site can smoothly perform work on the work machine 2.

[0045] After completing the above work on the work machine 2, the operator at the work site operates the first mode selection member 29 in the operating cabin 14 to set the control mode of the work machine 2 to the remote operation mode. The operator at the work site gets off the work machine 2 and operates the second mode selection member 30 to select the remote operation mode. After leaving the work machine 2, the operator at the work site operates the mobile communication unit 4 to release the start prohibited state of the work machine 2.

[0046] Accordingly, the remote operator operates the remote operation device 3 to transmit the start command signal to the work machine 2, thereby causing the work machine 2 to start. Subsequently, the remote operator operates the remote operation member 34 to perform work at the work site with the work machine 2. As described above, in the system 1 according to the present embodiment, the work machine 2 to be started by the remote operation can be started at an appropriate timing according to the condition of the work machine 2.

[0047] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications may be made without departing from the gist of the invention.

[0048] The work machine 2 is not limited to a bulldozer and may be another vehicle such as a wheel loader, a motor grader, a dump truck, or the like. The number of the work machine controlled by the system 1 is not limited to one and may be two or more. The power source 21 may be an electric motor. In this case, starting the work machine 2 may be starting the travel of the work machine 2, the motion of the work implement 13, or the like. Alternatively, the power source 21 may be a hybrid of the internal combustion Date Recue/Date Received 2023-09-21 engine and the electric motor.

[0049] The setting of the remote operation mode by the first mode selection member 29 may be omitted. The selection of the remote operation mode by the second mode selection member 30 may be omitted. The first mode selection member 29 and the second mode selection member 30 may be disposed on the outer surface of the work machine 2.
Alternatively, the first mode selection member 29 and the second mode selection member 30 may be disposed in the operating cabin 14.

[0050] In the above embodiment, the onboard controller 25 releases the start prohibited state of the work machine 2 when the start permission signal has been received from the mobile communication unit 4. However, the mobile communication unit 4 may transmit a start non-permission signal to the onboard controller 25. The onboard controller 25 may maintain the work machine 2 in the start prohibited state while the start non-permission signal is received from the mobile communication unit 4. The mobile communication unit 4 may stop the start non-permission signal according to the operation by the operator.
The onboard controller 25 may release the start prohibited state of the work machine 2 in a case where the transmission of the start non-permission signal is stopped.

[0051] The communication unit according to the present invention is not limited to the mobile communication unit 4 described above and may be changed. For example, the start permission signal may be transmitted to the onboard controller 25 by a communication unit provided at a base of the site, instead of the mobile communication unit 4. In this case, the operator at the work site may operate the communication unit to release the start prohibited state of the work machine 2 after returning to the base of the site. Alternatively, the operator at the work site may contact the base of the site and thus an operator at the base of the site may operate the communication unit to release the start prohibited state of the work machine 2.

[0052] A notification means such as a lamp indicating that the work machine 2 is in the start prohibited state or released from the start prohibited state may be provided in the operating cabin 14 of the work machine 1, on the outer surface of the work machine 1, on Date Recue/Date Received 2023-09-21 the remote operation device 3, or the like.
INDUSTRIAL APPLICABILITY

[0053] In the system and method according to the present disclosure, the work machine to be started by the remote operation can be started at an appropriate timing according to a condition of the work machine.
REFERENCE SIGNS LIST

[0054] 2 Work machine 3 Remote operation device 4 Mobile communication unit 25 Onboard controller 30 Mode selection member Date Recue/Date Received 2023-09-21

Claims

15

1. A system for controlling a work machine, the system comprising:
an onboard controller mounted on the work machine and configured to control the work machine;
a remote operation device configured to communicate with the onboard controller and transmit a start command signal for starting the work machine to the work machine; and a communication unit provided separately from the remote operation device, the communication unit being configured to communicate with the onboard controller and to be operated to switch the work machine from a start prohibited state to a start permitted state; wherein the onboard controller is configured to switch the work machine from the start prohibited state to the start permitted state according to an operation of the communication unit, prohibit the work machine from starting when the work machine is in the start prohibited state, even in a case where the start command signal has been received from the remote operation device, and start the work machine when the work machine is in the start permitted state, in a case where the start command signal has been received from the remote operation device.

2. The system according to claim 1, comprising:
a mode selection member mounted on the work machine and configured to be operated to select a remote operation mode of the work machine, wherein the onboard controller is configured to start the work machine when the remote operation mode is selected by the mode selection member and when the work machine is in the start permitted state, in a case where the start command signal has been received from the remote operation device.
Date Recue/Date Received 2023-09-21

3. The system according to claim 2, wherein the onboard controller is configured to prohibit the work machine from starting with the work machine in the start prohibited state, even when the remote operation mode is selected by the mode selection member.

4. The system according to claim 1, wherein the communication unit is configured to transmit a start permission signal for switching the work machine from the start prohibited state to the start permitted state to the onboard controller, and the onboard controller is configured to switch the work machine from the start prohibited state to the start permitted state, in a case where the start permission signal has been received.

5. The system according to claim 1, wherein the communication unit is configured to transmit a start non-permission signal for maintaining the work machine in the start prohibited state to the onboard controller, the communication unit is configured to stop transmission of the start non-permission signal according to an operation by an operator, and the onboard controller is configured to switch the work machine from the start prohibited state to the start permitted state, in a case where the transmission of the start non-permission signal has been stopped.

6. A method for controlling a work machine, the method comprising:
communicating with a communication unit;
switching the work machine from a start prohibited state to a start permitted state according to an operation of the communication unit;
communicating with a remote operation device;
determining whether a start command signal of the work machine has been Date Recue/Date Received 2023-09-21 received from the remote operation device;
starting the work machine when the work machine is in the start permitted state, in a case where the start command signal has been received from the remote operation device; and prohibiting the work machine from starting when the work machine is in the start prohibited state, even in a case where the start command signal has been received from the remote operation device.

7. The method according to claim 6, further comprising:
determining whether a remote operation mode of the work machine is selected by a mode selection member mounted on the work machine; and starting the work machine when the remote operation mode is selected by the mode selection member and when the work machine is in the start permitted state, in a case where the start command signal has been received from the remote operation device.

8. The method according to claim 7, comprising:
prohibiting the work machine from starting with the work machine in the start prohibited state, even when the remote operation mode is selected by the mode selection member.

9. The method according to claim 6, wherein the communication unit is configured to transmit a start permission signal for switching the work machine from the start prohibited state to the start permitted state according to an operation by an operator, the method further comprises:
determining whether the start permission signal has been received from the communication unit; and switching the work machine from the start prohibited state to the start permitted state, in a case where the start permission signal has been received.
Date Recue/Date Received 2023-09-21

10. The method according to claim 6, wherein the communication unit is configured to transmit a start non-permission signal for maintaining the work machine in the start prohibited state to the onboard controller, and the communication unit is configured to stop the start non-permission signal according to an operation by an operator, the method further comprises:
determining whether the start non-permission signal has been stopped; and switching the work machine from the start prohibited state to the start permitted state, in a case the start non-permission signal has been stopped.
Date Recue/Date Received 2023-09-21