Work machine system and method for controlling work machine

Abstract

According to the present invention, a transmitter transmits operation commands to a work machine. A jammer interferes with communication between the transmitter and the work machine. An instruction terminal is provided remotely from the transmitter and the work machine and configured to be capable of communicating with the jammer, and transmits interference instructions, instructing interference with the communication, in response to the operation commands. The work machine operates according to the operation commands received from the transmitter, periodically communicates with the transmitter, and stops operating when communication with the transmitter is disabled.

Description

Work machine system and work machine control method

[0001] This application claims priority to Japanese Patent Application No. 2024-104758, filed on June 28, 2024, the contents of which are incorporated herein by reference.

[0002] There is known technology for remotely operating a work machine (see, for example, Patent Document 1). At a work site where a work machine is in operation, various people are involved in the work, such as a work machine operator, on-site workers, supervisors, and construction managers.

[0003] Japanese Patent Application Laid-Open No. 2020-200660

[0004] When an abnormality occurs at a work site, there is a demand to stop a work machine. Persons at the work site who are not the operators of the work machine, such as workers, supervisors, and construction managers, usually do not have the means to issue an emergency stop command to the work machine. An object of the present disclosure is to provide a work machine system and a work machine control method that can stop a work machine from outside the work machine.

[0005] According to one aspect of the present invention, a work machine system includes a transmitter that transmits operation commands to a work machine, a jammer that interferes with communication between the transmitter and the work machine, and an instruction terminal that is provided remotely from the transmitter and the work machine and configured to be able to communicate with the jammer, and that transmits a jamming instruction to the jammer in response to an operation command, instructing the jammer to jam communication; the work machine operates in accordance with the operation command received from the transmitter, periodically communicates with the transmitter, and stops operating when communication with the transmitter becomes impossible.

[0006] According to the above aspect, a person other than the operator of the work machine can remotely stop the work machine.

[0007] Fig. 1 is a schematic diagram showing the configuration of a remote control system according to a first embodiment. Fig. 2 is a schematic diagram showing the configuration of a work machine according to a first embodiment. Fig. 3 is a schematic diagram showing the circuit configuration of a switch device according to a first embodiment. Fig. 4 is a schematic block diagram showing the software configuration of a terminal device according to a first embodiment. Fig. 5 is a sequence diagram showing the procedure for an emergency stop by the remote control system according to the first embodiment. Fig. 6 is a schematic block diagram showing the configuration of a computer according to at least one embodiment.

[0008] <First embodiment> <Configuration of remote operation system> Hereinafter, an embodiment will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of a remote operation system 1 according to a first embodiment. The remote operation system 1 is a system for remotely operating a work machine 10 provided at a work site.

[0009] The remote control system 1 includes a work machine 10, a wireless control device 20, a switch device 30, and a terminal device 40. The work machine 10 shown in Fig. 2 is a hydraulic excavator, but the remote control system 1 may include a different type of work machine 10, such as a wheel loader, a bulldozer, or a dump truck.

[0010] <<Work Machine 10>> The work machine 10 receives operation commands from the wireless control device 20 via short-range wireless communication, and drives in accordance with the operation commands. The work machine 10 and the wireless control device 20 are previously associated one-to-one, and the work machine 10 ignores operation commands from an incompatible wireless control device 20. The work machine 10 and the wireless control device 20 also periodically monitor their operating status or communication status. The work machine 10 stops the engine 121 when a state in which it is unable to communicate with the wireless control device 20 continues for a certain period of time. This allows the work machine 10 to be stopped when communication conditions deteriorate, ensuring safety at the work site.

[0011] Figure 2 is a schematic diagram showing the configuration of a work machine 10 according to the first embodiment. The work machine 10 shown in Figure 2 is a hydraulic excavator. The work machine 10 includes a traveling body 110, a rotating body 120, and a work implement 130.

[0012] The running body 110 supports the work machine 10 so that it can travel. The running body 110 is equipped with two caterpillar tracks 111, one on the left and one on the right, and two travel motors 112 for driving each caterpillar track 111. The rotating body 120 is supported on the running body 110 so that it can rotate about a rotation center. The work implement 130 is hydraulically driven. The work implement 130 is supported on the front part of the rotating body 120 so that it can be driven in the vertical direction.

[0013] The revolving unit 120 is equipped with an engine 121, a hydraulic pump 122, a control valve 123, and a swing motor 124. The engine 121 is a prime mover that drives the hydraulic pump 122. The engine 121 is an example of a power source. Note that a work machine 10 according to other embodiments may be equipped with an electric motor as a prime mover (power source). The hydraulic pump 122 is a variable displacement pump driven by the engine 121. The hydraulic pump 122 supplies hydraulic oil to each actuator (boom cylinder 131C, arm cylinder 132C, bucket cylinder 133C, travel motor 112, and swing motor 124) via a control valve 123. The control valve 123 controls the flow rate of hydraulic oil supplied from the hydraulic pump 122. The swing motor 124 is driven by hydraulic oil supplied from the hydraulic pump 122 via the control valve 123 to rotate the revolving unit 120. Note that the swing motor 124 according to other embodiments may be an electric motor instead of a hydraulic motor.

[0014] The work machine 130 includes a boom 131, an arm 132, a bucket 133 as a work implement, a boom cylinder 131C, an arm cylinder 132C, and a bucket cylinder 133C. Other examples of the work implement include end attachments such as a clam bucket, a tilt bucket, a tilt rotate bucket, a grapple, and a lifting magnet.

[0015] The base end of the boom 131 is rotatably attached to the revolving unit 120 via a boom pin, which is a joint. Note that in the work machine 10 shown in FIG. 1 , the boom 131 is provided in the center portion of the front of the revolving unit 120, but this is not limiting, and the boom 131 may be attached offset in the left-right direction. In this case, the center of rotation of the revolving unit 120 is not located on the operating plane of the work implement 130. The arm 132 connects the boom 131 and the bucket 133. The base end of the arm 132 is rotatably attached to the tip of the boom 131 via an arm pin, which is a joint. The bucket 133 is rotatably attached to the tip of the arm 132 via a pin, which is a joint. The bucket 133 functions as a container for collecting excavated soil and sand.

[0016] The boom cylinder 131C is a hydraulic cylinder for operating the boom 131. The base end of the boom cylinder 131C is attached to the revolving unit 120. The tip end of the boom cylinder 131C is attached to the boom 131. The arm cylinder 132C is a hydraulic cylinder for driving the arm 132. The base end of the arm cylinder 132C is attached to the boom 131. The tip end of the arm cylinder 132C is attached to the arm 132. The bucket cylinder 133C is a hydraulic cylinder for driving the bucket 133. The base end of the bucket cylinder 133C is attached to the arm 132. The tip end of the bucket cylinder 133C is attached to a link mechanism that rotates the bucket 133. Note that while each cylinder in the first embodiment is a hydraulic cylinder, in other embodiments, it may be another power cylinder, such as an electric cylinder. Furthermore, the actuator for driving the work implement 130 is not limited to a power cylinder and may be, for example, an electric motor provided at each joint. The electric motor may be driven by battery power.

[0017] It should be noted that when the work machine 130 is provided with a work implement having a movable part (such as a clam bucket, tilt bucket, tilt rotate bucket, or grapple), the work implement has an actuator for operating the movable part.

[0018] The work machine 10 is equipped with an imaging device 140, a wireless communication device 150, and a control device 160. The imaging device 140 is installed in the driver's cab of the revolving unit 120 or in a portion equivalent to the driver's cab so that the line of sight is directed forward of the revolving unit 120. The wireless communication device 150 receives operation commands from the wireless control device 20. The wireless communication device 150 may also transmit moving image data captured by the imaging device 140 to a display device that is visually recognized by the operator. Note that the wireless communication of operation commands and the wireless communication of moving image data may be performed using different methods. For example, the wireless communication of operation commands may be performed using low-power wireless communication, and the wireless communication of moving image data may be performed using a wireless LAN.

[0019] The control device 160 reads the operation command received by the wireless communication device 150 and outputs a control signal to the control valve 123. As a result, the work machine 10 operates in accordance with the operation command. The control device 160 also monitors the operation state or communication state of the remote controlled device 20 via the wireless communication device 150. The control device 160 outputs a stop command to the engine 121 when a state in which communication with the remote controlled device 20 cannot be performed continues for a certain period of time. The control device 160 also outputs a stop command to the engine 121 when an emergency stop command is received from the remote controlled device 20. For example, when a state in which communication with the remote controlled device 20 cannot be performed continues for a certain period of time, the control device 160 stops the engine 121 by stopping the supply of fuel to the engine 121. Note that when a state in which communication with the remote controlled device 20 cannot be performed continues for a certain period of time, or when an emergency stop command is received, the control device 160 stops the engine 121, but maintains the key-on state of the work machine 10.

[0020] <<Remote Control Device 20>> The remote control device 20 has levers and buttons corresponding to the actuators equipped on the work machine 10. Of the actuators equipped on the work machine 10, those whose speed or angular velocity can be controlled (e.g., the traveling body 110, the revolving body 120, the boom 131, the arm 132, the bucket 133, etc.) are operated with levers, and those whose on / off controls are controlled (e.g., the light, horn, swing lock, etc.) are operated with buttons. The remote control device 20 converts operation signals from the levers and buttons into operation commands in accordance with a predetermined protocol and transmits the operation commands as wireless signals. The wireless signals are transmitted on a channel preset in the remote control device 20, and the work machine 10 receives the wireless signals transmitted on the corresponding channel. The channel may be divided by, for example, frequency, time, code, etc. The remote control device 20 is an example of a transmitter that transmits operation commands to the work machine 10.

[0021] The wireless control device 20 also has an emergency stop button that brings the work machine 10 to an emergency stop, and pressing the emergency stop button sends an emergency stop command to the work machine 10. When the work machine 10 receives the emergency stop command, it stops the engine 121. This allows the operator to stop the work machine 10 in an emergency and ensure the safety of the work site. The wireless control device 20 has a plug 21 for receiving power from an external power source P. The wireless control device 20 operates using power supplied via the plug 21.

[0022] <<Switch Device 30>> Figure 3 is a schematic diagram showing the circuit configuration of the switch device 30 according to the first embodiment. The switch device 30 is provided in a power supply circuit connecting an external power source P and a wireless control device 20, and opens and closes the power supply circuit in accordance with instructions received from a terminal device 40 via a wireless LAN. The switch device 30 includes a plug receptacle 31, a plug 32, a connection line 33, a control unit 34, and a communication unit 35. The plug 21 of the wireless control device 20 is inserted into the plug receptacle 31 of the switch device 30. The plug 32 of the switch device 30 is inserted into the plug receptacle P1 of the external power source P. As a result, the switch device 30 is provided in the power supply circuit connecting the external power source P and the wireless control device 20. A connection line 33 connects the plug receptacle 31 and the plug 32. The connection line 33 is provided with a switching element 331 that switches between opening and closing the line connecting the plug receptacle 31 and the plug 32. The control unit 34 controls the opening and closing of the switching element 331 in accordance with instructions received from the communication unit 35. When the communication unit 35 receives a disconnection instruction, the control unit 34 outputs an open signal to the switching element 331. When the communication unit 35 receives a conduction instruction, the control unit 34 outputs a close signal to the switching element 331. The communication unit 35 connects to a network such as the Internet via a wireless LAN. The communication unit 35 receives instructions from a terminal device 40 connected to the network.

[0023] When the switch device 30 cuts off the power supply from the external power source P to the wireless control device 20, the wireless control device 20 is unable to transmit wireless signals. This disables communication between the work machine 10 and the wireless control device 20. In other words, the switch device 30 is an example of a jammer that interferes with communication between the wireless control device 20 and the work machine 10. The cut-off instruction is also an example of an interference instruction that instructs to interfere with communication.

[0024] <<Terminal Device 40>> The terminal device 40 is a terminal to be operated by a person (such as a worker, supervisor, or construction manager, hereinafter also referred to as a worker) working at the site where the work machine 10 is operating. Examples of the terminal device 40 include a smartphone, a tablet terminal, and a PC. The terminal device 40 is connected to a network and can communicate with the switch device 30 via the network. The terminal device 40 is an example of a communication device.

[0025] 4 is a schematic block diagram showing the software configuration of the terminal device 40 according to the first embodiment. The terminal device 40 comprises a storage unit 41, a selection unit 42, and a transmission unit 43. The storage unit 41 stores information about the work machines 10 operating at the site where the worker is working, in association with the ID of the switch device 30 corresponding to that work machine 10. Examples of information about the work machine 10 include the ID, chassis number, name, and model number of the work machine 10. The selection unit 42 displays a list of the work machines 10 stored in the storage unit 41 on the display, and accepts the selection of the work machine 10 to be brought to an emergency stop. The transmission unit 43 identifies the ID of the switch device 30 corresponding to the work machine 10 selected by the selection unit 42, and transmits a shut-off instruction addressed to that switch device 30 via the network.

[0026] The switch device 30 and the terminal device 40 may communicate directly or via a server. For example, the remote control system 1 may transmit a shutdown instruction from the terminal device 40 to the switch device 30 using the following procedure. The server previously stores the IDs of multiple switch devices 30 in association with their network addresses. The terminal device 40 transmits the shutdown instruction, including the ID of the switch device 30, to the server. Upon receiving the shutdown instruction from the terminal device 40, the server reads the ID of the switch device 30 included in the shutdown instruction. The server identifies the network address associated with the read ID and forwards the shutdown instruction to the network address. The server may store, for each switch device 30, information on the operation authority of the terminal device 40 or the worker. For example, the server stores the ID of the terminal device 40 or the worker who is authorized to issue a shutdown instruction, in association with the ID of the switch device 30. This allows the server to limit the terminal devices 40 or the workers who are authorized to shut down the power supply to the switch device 30.

[0027] <<Emergency Stop by Remote Control System 1>> Figure 5 is a sequence diagram showing the procedure for an emergency stop by the remote control system 1 according to the first embodiment. First, the operator turns on the key of the work machine 10 (step S1). This supplies power to the control device 160 of the work machine 10, enabling communication with the wireless control device 20. Before operating the work machine 10 using the wireless control device 20, the operator operates his / her own terminal device 40 to send a continuity command to the switch device 30 corresponding to the work machine 10 to be operated (step S2). This causes the control unit 34 of the switch device 30 to establish continuity with the connection line 33 connecting the external power source P and the wireless control device 20 (step S3). The wireless control device 20 receives power supply and starts up (step S4).

[0028] When the control device 160 and the remote control 20 are started, the control device 160 and the remote control 20 confirm communication with each other (step S5). When communication is confirmed, the control device 160 acquires an ID from the remote control 20 and performs authentication processing for the remote control 20 (step S6). Thereafter, the control device 160 and the remote control 20 periodically confirm communication.

[0029] Once authentication of the remote control device 20 is complete, it becomes possible to control the work machine 10 using the remote control device 20. The operator operates the remote control device 20 to turn on the engine, and the remote control device 20 transmits an engine-on command to the control device 160 (step S7). When the control device 160 receives the engine-on command from the authenticated remote control device 20, it starts driving the engine 121 (step S8).

[0030] Thereafter, when an emergency occurs, the worker who notices the emergency operates his / her own terminal device 40 to select a work machine 10 that is to be subjected to an emergency stop from among the work machines 10 present at the work site. This causes the terminal device 40 to transmit a shut-off instruction addressed to the switch device 30 corresponding to the selected work machine 10 (step S9). When the control unit 34 of the switch device 30 receives the shut-off instruction, it shuts off the connection line 33 that connects the external power source P and the remote control device 20 (step S10). This stops the supply of power to the remote control device 20, causing the remote control device 20 to shut down (step S11).

[0031] When the remote control device 20 is stopped, the control device 160 detects that no response to the communication connection confirmation has been received from the remote control device 20 for a certain period of time or more, and determines that communication has been interrupted (step S12). When the control device 160 determines that communication has been interrupted, it stops the operation of the engine 121 (step S13).

[0032] <<Actions and Effects>> As described above, the remote control system 1 according to the first embodiment has the following functions. The work machine 10 operates in accordance with operation commands received from the wireless control device 20, periodically communicates with the wireless control device 20, and stops operation when communication with the wireless control device 20 becomes impossible. The wireless control device 20 transmits operation commands to the work machine 10. The switch device 30 interferes with communication between the wireless control device 20 and the work machine 10. The terminal device 40 is provided remotely from the wireless control device 20, and is configured to be able to communicate with the wireless control device 20. The wireless control device 20 transmits a cut-off command to the switch device 30 in response to operation by the worker, to disrupt communication with the wireless control device 20. As a result, the remote control system 1 can bring the work machine 10 to an emergency stop by cutting off the power supply to the wireless control device 20 through operation of the terminal device 40. Therefore, according to the first embodiment, by installing software for sending shutdown instructions on a general-purpose terminal device 40 used by the worker, there is no need to prepare a wireless control device 20 with an emergency stop button for each worker, and any worker can bring the work machine 10 to an emergency stop.

[0033] <Other Embodiments> One embodiment has been described in detail above with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes and the like are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel. The remote control device 20 according to the above-described embodiment may be configured as a single device, or the configuration of the remote control device 20 may be realized by a plurality of devices. For example, in a remote control system 1 according to another embodiment, the remote control device 20 may be further connected to a remote operation computer via a network, and the remote control device 20 may relay operation commands input from the operation computer to the work machine 10.

[0034] The remote control system 1 according to the embodiment described above disrupts communication between the remote control device 20 and the work machine 10 by using the switch device 30 to cut off the power supply to the remote control device 20, but is not limited to this. For example, the switch device 30 according to another embodiment may be provided inside the remote control device 20 and disrupt communication between the remote control device 20 and the work machine 10 by partially cutting off the current in the control circuit and communication circuit of the remote control device 20. Furthermore, the remote control system 1 according to another embodiment may be provided with a shielding device that blocks radio signals transmitted from the antenna, instead of the switch device 30. In this case, the shielding device switches between a state in which radio signals are blocked and a state in which radio signals are allowed to pass, in accordance with instructions from the terminal device. This shielding device is an example of a jammer that disrupts communication between the remote control device 20 and the work machine 10.

[0035] <Computer Configuration> Figure 6 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. The control device 160 of the work machine 10, the remote control device 20, and the control unit 34 of the switch device 30 described above are each implemented in the computer 90. The operation of each of the processing units described above is stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, loads it into the main memory 92, and executes the above-mentioned processing in accordance with the program. The processor 91 also allocates storage areas in the main memory 92 corresponding to each of the storage units described above in accordance with the program. Examples of the processor 91 include a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), and a microprocessor.

[0036] The program may be for implementing some of the functions to be performed by the computer 90. For example, the program may be implemented in combination with other programs already stored in storage or in combination with other programs implemented in other devices. In another embodiment, the computer 90 may include a custom large-scale integrated circuit (LSI) such as a programmable logic device (PLD) in addition to or instead of the above configuration. Examples of PLDs include programmable array logic (PAL), generic array logic (GAL), complex programmable logic device (CPLD), and field programmable gate array (FPGA). In this case, some or all of the functions implemented by the processor 91 may be implemented by the integrated circuit. Such an integrated circuit is also an example of a processor. In another embodiment, the computer 90 may be virtualized on one or more computers.

[0037] Examples of storage 93 include a magnetic disk, a magneto-optical disk, an optical disk, and a semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of computer 90, or an external medium connected to computer 90 via interface 94 or a communication line. Furthermore, when this program is distributed to computer 90 via a communication line, computer 90 that receives the program may load the program into main memory 92 and execute the above-described processing. In at least one embodiment, storage 93 is a non-transitory tangible storage medium.

[0038] The program may also be a program for realizing part of the above-described functions. Furthermore, the program may be a so-called differential file (differential program) that realizes the above-described functions in combination with another program already stored in storage 93.

[0039] According to the above aspect, a person other than the operator of the work machine can remotely stop the work machine.

[0040] 1...Remote operation system 10...Work machine 110...Traveling body 111...Crawler 112...Travel motor 120...Swinging body 121...Engine 122...Hydraulic pump 123...Control valve 124...Swing motor 130...Work machine 131...Boom 131C...Boom cylinder 132...Arm 132C...Arm cylinder 133...Bucket 133C...Bucket cylinder 140...Imaging device 150...Wireless communication device 160...Control device 20...Wireless operation device 21...Plug 30...Switch device 31...Plug receptacle 32...Plug 33...Connection line 331...Switching element 34...Control unit 35...Communication unit 40...Terminal device 41...Memory unit 42...Selection unit 43...Transmission unit 90...Computer 91...Processor 92...Main memory 93...Storage 94...Interface P...External power supply P1...Plug receptacle

Claims

1. A work machine system comprising: a transmitter that transmits operation commands to a work machine; a jammer that interferes with communication between said transmitter and said work machine; and an instruction terminal that is provided remotely from said transmitter and said work machine and configured to be able to communicate with said jammer, and that transmits jamming commands to said jammer in response to an operation command, instructing said jammer to jam communications; wherein said work machine operates in accordance with the operation commands received from said transmitter, periodically communicates with said transmitter, and stops operating when communication with said transmitter becomes impossible.

2. The work machine system according to claim 1, wherein the jammer interrupts communication between the transmitter and the work machine by cutting off power supply from a power source to the transmitter.

3. A work machine system as described in claim 2, wherein the jammer is connected to the plug receptacle of the power supply and the plug of the transmitter to form a circuit that supplies power from the power supply to the transmitter, and cuts off the circuit when the jamming instruction is received.

4. The work machine system according to claim 1, wherein the work machine stops the prime mover when communication with the transmitter becomes impossible.

5. A control method for a work machine that operates in accordance with an operation command received from a transmitter and stops operation when communication with said transmitter becomes impossible, wherein an instruction terminal provided remotely from said transmitter and said work machine transmits a jamming command to a jammer in accordance with the operation command, instructing the jammer to jam communication between said transmitter and said work machine, said jammer interferes with communication between said transmitter and said work machine in accordance with the jamming command received from said transmitter, and said work machine stops operation when communication with said transmitter becomes impossible.

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