JP7510381B2 - Control system for work machines - Google Patents

Description

The present invention relates to a control system for a work machine.

Technology is being developed that detects a worker approaching a work machine and restricts the operation of the work machine when there is a possibility of contact between the worker and the work machine. However, this technology can reduce work efficiency by restricting the operation of the work machine too frequently. For example, in small work sites such as road construction, workers often work close to the work machine. In this case, even if the worker works while paying close attention to the work machine, the operation of the work machine will be restricted every time an approaching worker is detected. Therefore, the challenge is to improve work efficiency while preventing contact between the work machine and the worker.

To address these issues, there is a method for adjusting the degree of restriction on the operation of the work machine depending on the experience and skill level of the worker who works around the work machine. If the worker is an experienced worker, he or she will have a thorough understanding of the characteristics of the work machine (blind spots, direction and speed of the work machine's operation), the characteristics of the operator (operation proficiency and personality), the characteristics of the work site (weather, road conditions, slope, other machines around the work machine, number and placement of workers, areas where there is a high possibility of contact between the work machine and the worker), the content of the work (plan, progress, the positional relationship of the work machine to other machines), etc. For this reason, an experienced worker will be able to predict the operation of the work machine even if he or she is working close to the work machine, and will be able to respond appropriately to the approach of the work machine.

On the other hand, unskilled workers often do not fully understand the above-mentioned characteristics. Therefore, just like an experienced worker, an unskilled worker may not be able to respond appropriately to the approach of a work machine even if he or she is working near the work machine. In other words, an unskilled worker is more likely to come into contact with a work machine than an experienced worker. By utilizing such worker characteristics and appropriately adjusting the degree of restriction on the operation of the work machine according to the worker's level of skill, it is possible to prevent the operation of the work machine from being restricted more than necessary, making it possible to achieve both productivity and safety.

Patent Document 1 discloses a collaborative safety control system that acquires human information and controls machines based on the acquired human information in an environment where humans and machines cooperate. The human information includes safety qualification information held by the person. The collaborative safety control system described in Patent Document 1 controls the speed of the machine and sets the range of the zone based on the acquired safety qualification information. The zone is set to stop the machine when a person enters the zone. The safety qualification information is information on the qualifications certified by a third party based on the knowledge and ability that a person has regarding safety. Examples of safety qualification information include the Safety Basic Assessor (SBA), Safety Sub-Assessor (SSA), Safety Assessor (SA), and Safety Lead Assessor (SLA) certified by the Safety Basic Assessor Qualification Certification System and the Safety Assessor Qualification Certification System.

JP 2018-202563 A

However, when controlling machinery according to safety qualification information held by workers, as in the technology described in Patent Document 1, it is not possible to distinguish the capabilities of workers at a work site where the workers have not obtained certification including safety qualification information. There are also many types of certification. In some cases, the organization to which the worker belongs has established its own certification, and it is difficult to provide a system that can handle all of these types of certification. Therefore, the technology described in Patent Document 1 may not be able to appropriately restrict the operation of the work machine according to the worker who enters the working range of the work machine.

The present invention aims to provide a control system for a work machine that can appropriately restrict the operation of a work machine depending on the person who enters the working range of the work machine, regardless of the safety qualification information possessed by the person.

The control system for a work machine according to one aspect of the present invention includes a wireless terminal carried by a person, and a control device that performs control to restrict the operation of the actuator of the work machine when the intrusion of the person into the working range of the work machine is detected based on a signal transmitted from the wireless terminal. The control device determines whether the person has intruded into the working range in compliance with a predetermined rule based on at least one of the state of the work machine and the state of the person, stores information correlating the determination result with the identification information of the person as intrusion history information, calculates a rule compliance level indicating the degree to which the person intruded into the working range in compliance with the rule based on the intrusion history information, and when the intrusion of the person into the working range is detected, controls the operation of the actuator so that the degree of restriction on the operation of the actuator is smaller when the degree of rule compliance of the person who has intruded into the working range is high than when the degree of rule compliance is low.

The present invention provides a work machine control system that can appropriately restrict the operation of the work machine depending on the person who enters the work range of the work machine.

1 is a diagram showing the configuration of a control system for a work machine according to a first embodiment of the present invention. FIG. 1 is a diagram showing the configuration of a hydraulic system mounted on a hydraulic excavator. FIG. 4 is a functional block diagram relating to the operation limit control by the vehicle body controller. FIG. 13 is a diagram showing intrusion history information. 5 is a diagram showing an engine speed command value output from an output signal generating unit according to the degree of restriction of an actuator, and the control content of a pilot pressure control valve by the output signal generating unit according to the degree of restriction. FIG. FIG. 11 is a diagram showing a threshold value table stored in a non-volatile memory in the hydraulic excavator according to the second embodiment of the present invention. FIG. 11 is a diagram showing a threshold value table stored in a non-volatile memory in a hydraulic excavator according to a modified example of the second embodiment of the present invention. FIG. 13 is a diagram showing the configuration of a control system for a construction machine according to a third embodiment of the present invention. FIG. 2 is a top view of the wheel loader, showing the working range when the wheel loader is stopped. FIG. 2 is a top view of the wheel loader, showing the working range when the wheel loader is traveling. FIG. 13 is a diagram showing the configuration of a control system for a construction machine according to a fourth embodiment of the present invention. FIG. 13 is a functional block diagram relating to operation limiting control by a vehicle body controller in the control system for a work machine according to Modification 1-1. FIG. 13 is a functional block diagram relating to operation limiting control by a vehicle body controller in the control system for a work machine according to Modification 1-2.

The following describes a work machine control system according to an embodiment of the present invention with reference to the drawings.

First Embodiment
FIG. 1 is a diagram showing the configuration of a construction machine control system 1 according to a first embodiment of the present invention. In this embodiment, an example will be described in which the construction machine is a crawler-type hydraulic excavator 100. The construction machine control system 1 has the hydraulic excavator 100 and an RFID tag 4, which is a wireless terminal carried by a worker (person) performing work around the hydraulic excavator 100. When there are multiple workers, each of the workers carries an RFID tag 4 that holds a unique worker ID (identification information) for identifying the individual. When the RFID tag 4 detects a magnetic field generated by a magnetic field generating device 61, which will be described later, it transmits radio waves including the worker ID held by the RFID tag 4.

The hydraulic excavator 100 comprises a machine body (vehicle body) 104 and a working device 110 attached to the machine body 104. The machine body 104 comprises a running body 102 and a rotating body 103 that is rotatably mounted on the running body 102, and the working device 110 is attached to the front of the rotating body 103. The running body 102 runs by driving a pair of left and right crawlers by running motors 19L, 19R (only the left running motor 19L is shown in FIG. 1). The rotating body 103 is driven by a swing motor 20 and rotates (i.e., swings) relative to the running body 102.

The rotating body 103 has a cab 107 and an engine room 106 provided to the rear of the cab 107. The engine room 106 houses the engine 80 and hydraulic equipment such as a hydraulic pump driven by the engine 80. A work device 110 is rotatably connected to the center of the front part of the frame of the rotating body 103.

The working device 110 is a multi-jointed working device having a number of driven members that are rotatably connected and a number of hydraulic cylinders that drive the driven members. In this embodiment, the three driven members, a boom 111, an arm 112, and a bucket 113, are connected in series. The base end of the boom 111 is rotatably connected to the front of the rotating body 103. The base end of the arm 112 is rotatably connected to the tip of the boom 111. The bucket 113 is rotatably connected to the tip of the arm 112.

The boom 111 is driven by a hydraulic cylinder (hereinafter also referred to as boom cylinder 111a) which is an actuator, and rotates relative to the rotating body 103. The arm 112 is driven by a hydraulic cylinder (hereinafter also referred to as arm cylinder 112a) which is an actuator, and rotates relative to the boom 111. The bucket 113 is driven by a hydraulic cylinder (hereinafter also referred to as bucket cylinder 113a) which is an actuator, and rotates relative to the arm 112.

The hydraulic excavator 100 is equipped with a worker detection device 60 that detects the intrusion of a worker (person) into the working range of the hydraulic excavator 100 based on a signal transmitted from the RFID tag 4, and a vehicle control controller 120 that is a control device that controls each part of the hydraulic excavator 100. The worker detection device 60 has a magnetic field generating device 61 that generates a magnetic field that excites the RFID tag 4, a receiver 62 that receives radio waves generated by the RFID tag 4 due to the magnetic field generated by the magnetic field generating device 61, and a detection control device 63 that controls the magnetic field generated by the magnetic field generating device 61 based on a control signal from the vehicle control controller 120, and obtains the worker ID contained in the radio waves (signals) received by the receiver 62 and outputs it to the vehicle control controller 120.

The magnetic field generating device 61 is disposed, for example, on the central axis of rotation of the rotating body 103. The magnetic field generating device 61 generates a magnetic field of a certain strength. In this case, the magnetic field detectable area 69 is a certain range centered on the magnetic field generating device 61. The magnetic field detectable area 69 is a range in which the magnetic field generated by the magnetic field generating device 61 can be received with the magnetic field detection sensitivity of the RFID tag 4. When the RFID tag 4 receives the magnetic field from the magnetic field generating device 61, it outputs radio waves to the receiver 62. Therefore, the magnetic field detectable area 69 is an area in which the RFID tag 4 can be detected by the worker detection device 60.

The magnetic field generated by the magnetic field generating device 61 forms a hemispherical magnetic field detectable area 69. The size of the magnetic field detectable area 69 can be changed by adjusting the strength of the magnetic field generated by the magnetic field generating device 61. As described below, when an operator enters the magnetic field detectable area 69, the operation of the hydraulic excavator 100 is restricted. Therefore, if the magnetic field detectable area 69 is too small compared to the working range, the restriction on the operation of the hydraulic excavator 100 may not function properly when an operator approaches. Conversely, if the magnetic field detectable area 69 is too large, the operation of the hydraulic excavator 100 will be restricted even if there is no possibility of a collision, resulting in reduced work efficiency. Therefore, in this embodiment, the magnetic field detectable area 69 is set to a size equal to or larger than the working range of the hydraulic excavator 100, but not larger than necessary.

The magnetic field detectable area 69 is not limited to a hemispherical shape, and may be, for example, a semi-ellipsoid. The working range of the hydraulic excavator 100 is the range that the tip of the working device 110 can reach when the working device 110 and the rotating body 103 are operated while the running body 102 of the hydraulic excavator 100 is stopped. The working range is set, for example, based on the maximum turning radius of the hydraulic excavator 100. The maximum turning radius corresponds to the length from the central axis of the rotating body 103 to the tip of the bucket 113 when the working device 110 is extended forward (in a direction perpendicular to the central axis of the turning).

As described above, the RFID tag 4 holds a unique worker ID, and when it is present within the magnetic field detectable area 69, it generates radio waves containing the worker ID. The RFID tag 4 is attached, for example, to the worker's helmet. The worker always carries the same RFID tag 4. This allows the vehicle control controller 120 to identify the worker from the worker ID.

When the detection control device 63 receives the radio waves generated by the RFID tag 4 with the receiver 62, it detects that the worker has entered the magnetic field detectable area 69, i.e., that the worker has entered the working range of the hydraulic excavator 100. The detection control device 63 outputs the worker ID of the worker who has entered the working range of the hydraulic excavator 100 to the vehicle body control controller 120. The vehicle body control controller 120 detects that the worker has entered the working range of the hydraulic excavator 100 by receiving the worker ID of the worker from the detection control device 63. When the vehicle body control controller 120 detects that the worker has entered the working range of the hydraulic excavator 100, it executes operation restriction control that restricts the operation of the actuator of the hydraulic excavator 100. Details of the operation restriction control will be described later.

The hydraulic system installed in the hydraulic excavator 100 will be described with reference to Figure 2. Figure 2 is a diagram showing the configuration of the hydraulic system installed in the hydraulic excavator 100. In Figure 2, mechanical connections are indicated by double lines, hydraulic oil lines 24 are indicated by thick solid lines, pilot lines 29 are indicated by thick dashed lines, and electrical systems (signal lines) are indicated by thin dashed lines.

The hydraulic excavator 100 includes an engine 80, a main pump 11, a pilot pump 12, a control valve 13, an operating device 14, an operating pressure sensor 15, a vehicle control controller 120, an engine controller 17, a gate lock device 18, travel motors 19L and 19R, a swing motor 20, a pilot pressure control valve 21, a gate lock solenoid valve 25, and an alarm device 22.

The hydraulic system is provided with multiple actuators, but FIG. 2 shows only the travel motors 19L, 19R that drive the travel body 102 and the swing motor 20 that drives the swing body 103, and does not show the other actuators. An operating device that operates the actuator and a pilot pressure control valve 21 provided between the operating device and the control valve 13 are also provided for each of the multiple actuators, but FIG. 2 only shows the configuration for controlling one actuator as a representative. Furthermore, the control valve 13 has a flow control valve provided for each of the multiple actuators, but the flow control valves are not shown.

The engine 80 is the power source of the hydraulic excavator 100 and is, for example, an internal combustion engine such as a diesel engine. The main pump 11 is a variable displacement hydraulic pump, and the pilot pump 12 is a fixed displacement hydraulic pump. The output shaft of the engine 80 is connected to the input shafts of the main pump 11 and the pilot pump 12. The main pump 11 and the pilot pump 12 are driven by the power of the engine 80.

The main pump 11 discharges hydraulic oil into the hydraulic oil line 24 and supplies the hydraulic oil to the control valve 13 via the hydraulic oil line 24. The pilot pump 12 supplies hydraulic oil to the operating device 14. The operating device 14 reduces the pilot primary pressure supplied from the pilot pump 12 and supplies pilot pressure (operating pressure) to the pressure receiving section of the flow control valve (not shown) in the control valve 13.

The control valve 13 has multiple flow control valves (not shown) that control the flow of hydraulic oil supplied from the main pump 11 to each actuator. The control valve 13 selectively supplies hydraulic oil discharged from the main pump 11 to the actuators.

The operating device 14 commands the operation of the actuator by outputting an operating pressure. The operating device 14 has an operating member that is tilted by the operator, and a pair of pressure reducing valves using a hydraulic pilot system. Examples of the operating device 14 include a travel operating device having a travel lever and a travel pedal as operating members for operating the left and right travel motors 19L, 19R, and a turning operating device having a turning lever as an operating member for operating the turning motor 20.

The pressure reducing valve of the operating device 14 reduces the pilot primary pressure supplied from the pilot pump 12 to generate a pilot secondary pressure (also referred to as operating pressure) that corresponds to the amount of operation and the direction of operation of the operating member. The operating pressure is guided to the pressure receiving part of the flow control valve that corresponds to the operated operating member and the operating direction, and is used as an operating signal that drives the flow control valve to operate the actuator. When the operating member of the operating device 14 is operated, an operating signal that corresponds to the operating direction and amount of operation is guided to the flow control valve of the control valve 13, and the flow control valve operates. As a result, the hydraulic oil discharged from the main pump 11 is supplied to the actuator corresponding to that flow control valve through the flow control valve of the control valve 13, and the actuator is driven.

The operating pressure sensor 15 detects the operating pressure (i.e., the amount of operation) generated by the pressure reducing valve of the operating device 14 and outputs the detection result to the vehicle control controller 120.

The pilot pressure control valve 21 is an electromagnetic proportional pressure reducing valve provided in the pilot line 29 between the operating device 14 and the pressure receiving part of the flow control valve of the control valve 13. The pilot pressure control valve 21 generates a corrected operating pressure by further reducing the operating pressure generated by the pressure reducing valve of the operating device 14 in response to a control signal from the vehicle body controller 120.

When the operating pressure generated by the pressure reducing valve of the operating device 14 is introduced to the flow control valve without being reduced by the pilot pressure control valve 21, the actuator operates at a speed corresponding to the amount of operation of the operating device 14. In contrast, when the operating pressure generated by the pressure reducing valve of the operating device 14 is reduced by the pilot pressure control valve 21 and the corrected operating pressure generated by the pilot pressure control valve 21 is introduced to the flow control valve, the actuator operates at a speed lower than the speed corresponding to the amount of operation of the operating device 14. In other words, the operation of the actuator that operates in response to the corrected operating pressure generated by the pilot pressure control valve 21 is limited.

The vehicle body control controller 120 is composed of a computer equipped with a processor 121 such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), or DSP (Digital Signal Processor), a non-volatile memory 122 such as a ROM (Read Only Memory), flash memory, or hard disk drive, a volatile memory 123 known as a RAM (Random Access Memory), an input/output interface 124, and other peripheral circuits. The vehicle body control controller 120 may be composed of one computer or multiple computers.

The non-volatile memory 122 stores programs capable of executing various calculations. In other words, the non-volatile memory 122 is a storage medium capable of reading programs that realize the functions of this embodiment. The processor 121 is a processing device that expands the programs stored in the non-volatile memory 122 into the volatile memory 123 and executes the calculations, and performs predetermined calculations on signals taken in from the input/output interface 124, the non-volatile memory 122, and the volatile memory 123 in accordance with the programs.

The vehicle body controller 120 is connected to the operating pressure sensor 15, the engine controller 17, the gate lock device 18, the gate lock solenoid valve 25, the pilot pressure control valve 21, the alarm device 22, the engine control dial 26, and the detection control device 63 of the worker detection device 60. The input section of the input/output interface 124 converts signals input from various devices (such as the engine controller 17, the engine control dial 26, the gate lock device 18, the operating pressure sensor 15, and the detection control device 63 of the worker detection device 60) so that they can be calculated by the processor 121. The input/output interface 124 also generates an output signal according to the calculation result of the processor 121, and outputs the signal to various devices (such as the pilot pressure control valve 21, the alarm device 22, the engine controller 17, the gate lock solenoid valve 25, and the detection control device 63 of the worker detection device 60).

The vehicle body controller 120 outputs an engine speed command value corresponding to the amount of operation of the engine control dial 26 to the engine controller 17. The engine controller 17 controls the engine 80 so that the actual speed of the engine 80 becomes equal to the engine speed command value.

The gate lock device 18 is a lock device that can be switched between an unlocked position that allows the actuator to be operated by the operating device 14 and a locked position that prevents the actuator from being operated by the operating device 14. The gate lock device 18 includes a gate lock lever 18a that is selectively operated between a locked position and an unlocked position, and a gate lock solenoid valve 25 that is switched between a blocked position and a connected position depending on the operating position of the gate lock lever 18a. The vehicle body control controller 120 detects the operating position of the gate lock lever 18a based on a signal output from the gate lock device 18, and controls the gate lock solenoid valve 25 depending on the operating position of the gate lock device 18. When the gate lock lever 18a is operated to the locked position, the vehicle body control controller 120 switches the gate lock solenoid valve 25 to the blocked position. When the gate lock lever 18a is operated to the unlocked position, the vehicle body control controller 120 switches the gate lock solenoid valve 25 to the connected position.

When the gate lock solenoid valve 25 is in the shutoff position, the pilot primary pressure supplied from the pilot pump 12 to the operating device 14 is shut off by the gate lock solenoid valve 25, and the actuator cannot be operated by the operating device 14. When the gate lock solenoid valve 25 is in the open position, the pilot primary pressure is supplied from the pilot pump 12 to the operating device 14. Therefore, the pilot pressure (operating pressure) generated by the operating device 14 according to the amount of operation is guided to the flow control valve, and the actuator can be operated by the operating device 14.

When the gate lock device 18 is in the locked position, the vehicle body controller 120 disables the actuator and reduces power by issuing an idle speed command to the engine controller 17.

The operation restriction control executed by the vehicle body controller 120 will be described. In this embodiment, as the first operation restriction control, the vehicle body controller 120 outputs a power reduction command (≒ engine speed reduction command) to the engine controller 17 to reduce the speed of the engine 80. As the second operation restriction control, the vehicle body controller 120 drives the pilot pressure control valve 21 to reduce or cut off the pilot pressure (operation pressure) from the operation device 14 to the control valve 13, thereby slowing down or stopping the operation of the actuator. Furthermore, the vehicle body controller 120 drives the alarm device 22 to issue an alarm to the driver and the operator.

When the gate lock device 18 is operated to the locked position, the actuator will not operate. That is, in this case, the hydraulic excavator 100 will not come into contact with the worker when it operates. When the gate lock device 18 is in the locked position, the vehicle body controller 120 will not output a power reduction command to the engine controller 17 even if the worker enters the working range of the hydraulic excavator 100. In addition, in this case, the vehicle body controller 120 will not control the pilot pressure control valve 21. Furthermore, in this case, the vehicle body controller 120 will not issue an alarm to the operator or worker using the alarm device 22.

The alarm device 22 is a device that issues a warning when a worker enters the working range of the hydraulic excavator 100. For example, the alarm device 22 includes a light-emitting device 22a that emits light to warn workers around the hydraulic excavator 100, and a sound output device 22b such as a buzzer that issues a warning sound to warn workers around the hydraulic excavator 100. The light-emitting device 22a includes, for example, multiple light-emitting diodes (LEDs).

As described above, when the gate lock device 18 is in the locked position, the actuator will not operate. Therefore, when the gate lock device 18 is in the locked position, the vehicle body controller 120 controls the light-emitting device 22a to light up the LED in a non-warning color (green), which indicates that the worker is permitted to enter the work area. This allows the worker to visually know that he or she is permitted to enter the work area.

On the other hand, when the gate lock device 18 is in the unlocked position, there is a possibility that the actuator will operate. Therefore, when the gate lock device 18 is in the unlocked position, the vehicle body control controller 120 controls the light emitting device 22a to light up the LED in a warning color (red) to indicate to the worker that entry into the work area is prohibited. This allows the worker to know visually and audibly that entry into the work area is prohibited. Note that when the gate lock device 18 is in the unlocked position and a worker enters the work area, the vehicle body control controller 120 causes the sound output device 22b to emit an alarm sound.

The functions of the vehicle body control controller 120 will be described in detail with reference to FIG. 3. FIG. 3 is a functional block diagram related to the operation restriction control by the vehicle body control controller 120. As shown in FIG. 3, the vehicle body control controller 120 has the functions of a state management unit 31, a rule compliance determination unit 32, an intrusion history storage unit 33, a restriction degree setting unit 34, and an output signal generation unit 35.

The status management unit 31 detects the operating position (unlocked position/locked position) of the gate lock device 18, which can be switched between an operable state and an inoperable state of the actuator, and determines whether the hydraulic excavator 100 is in an operable state based on the detected operating position. When the gate lock lever 18a is in the unlocked position and the actuator is in an operable state, the status management unit 31 determines that the hydraulic excavator 100 is in an operable state. When the gate lock device 18 is in the locked position and the actuator is in an inoperable state, the status management unit 31 determines that the hydraulic excavator 100 is not in an operable state (i.e., in an inoperable state).

The rule compliance determination unit 32 acquires the worker ID of the worker who has entered the working range of the hydraulic excavator 100 from the worker detection device 60. The rule compliance determination unit 32 executes rule compliance determination processing based on the determination result from the status management unit 31 and the detection result from the worker detection device 60. The rule compliance determination processing is processing for determining whether or not the worker has entered the working range in compliance with predetermined rules.

The rule in this embodiment is that when the hydraulic excavator 100 is in a workable state, entry into the working range is prohibited, and when the hydraulic excavator 100 is in a workable state, entry into the working range is permitted.

Specifically, when the hydraulic excavator 100 is in an unworkable state (i.e., entry into the work area is permitted) and a worker ID is input from the worker detection device 60, the rule compliance determination unit 32 determines that the worker has entered the work area in compliance with the rules. When the hydraulic excavator 100 is in an workable state (i.e., entry into the work area is prohibited) and a worker ID is input from the worker detection device 60, the rule compliance determination unit 32 determines that the worker has entered the work area without complying with the rules.

The intrusion history storage unit 33 stores information associating the result of the rule compliance determination process by the rule compliance determination unit 32 with the worker ID of the intruder as intrusion history information.

The intrusion history information stored in the intrusion history storage unit 33 will be described with reference to FIG. 4. FIG. 4 is a diagram showing the intrusion history information. As shown in FIG. 4, the intrusion history information is information in which a worker ID (identification information), a total number of intrusions [times], a number of appropriate intrusions [times], and a rule compliance level [%] are associated with each other. The total number of intrusions is the total number of times that a worker intrudes into the work area regardless of whether or not the worker complies with a predetermined rule. The appropriate number of intrusions is the number of times that a worker intrudes into the work area by complying with a rule. The rule compliance level is the ratio of the appropriate number of intrusions to the total number of intrusions (appropriate number of intrusions/total number of intrusions).

When the rule compliance determination unit 32 determines that the worker has entered the work area in compliance with the rules, the intrusion history storage unit 33 adds 1 to each of the total number of intrusions and the appropriate number of intrusions in the intrusion history information. When the rule compliance determination unit 32 determines that the worker has entered the work area without complying with the rules, the intrusion history storage unit 33 adds 1 to the total number of intrusions in the intrusion history information, and does not add 1 to the appropriate number of intrusions.

When the total number of intrusions in the intrusion history information is updated, the intrusion history storage unit 33 calculates the degree of rule compliance (number of appropriate intrusions/total number of intrusions) based on the total number of intrusions and the number of appropriate intrusions, and updates the degree of rule compliance in the intrusion history information. In other words, the intrusion history storage unit 33 also functions as a rule compliance calculation unit that calculates the degree of rule compliance that indicates the degree to which a worker intruded into the work area in compliance with the rules, based on the intrusion history information.

For example, when worker A, whose worker ID is 001, enters the working range of the hydraulic excavator 100 for the first time and worker A enters the working range in compliance with the rules, the total number of intrusions and the number of appropriate intrusions will each be 1 [time], and the degree of compliance with the rules will be 100% (= 1 [time] / 1 [time] x 100).

For example, worker B, whose worker ID is 002, has entered the work area 12 times, of which 6 times he entered the work area in compliance with the rules. Therefore, worker B's rule compliance level is 50% (= 6 times / 12 times x 100). If worker B enters the work area without complying with the rules, the intrusion history information is updated to 13 times in total, and the rule compliance level is updated to 46% (= 6 times / 13 times x 100).

As shown in FIG. 3, when the rule compliance determination unit 32 determines that a worker has entered the work area (i.e., when the intrusion of a worker into the work area is detected), the restriction degree setting unit 34 selects and sets the restriction degree from among "severe," "medium," or "light" based on the worker's degree of rule compliance. A detailed explanation is given below.

The restriction degree setting unit 34 determines whether the worker's rule compliance is equal to or lower than the severe threshold. If the rule compliance is equal to or lower than the severe threshold, the restriction degree setting unit 34 sets the restriction degree to "severe." If the rule compliance is greater than the severe threshold, the restriction degree setting unit 34 determines whether the worker's rule compliance is equal to or lower than the medium threshold. If the rule compliance is greater than the severe threshold and equal to or lower than the medium threshold, the restriction degree setting unit 34 sets the restriction degree to "medium." If the rule compliance is greater than the medium threshold, the restriction degree setting unit 34 sets the restriction degree to "light." The severe threshold and the medium threshold are stored in advance in the non-volatile memory 122. The severe threshold is, for example, any numerical value in the range of 5% to 50%. The medium threshold is, for example, any numerical value in the range of 40% to 90% and is greater than the severe threshold. The degree of restriction increases in stages from "light," "medium," to "severe." In other words, "severe" means that the operation of the hydraulic excavator 100 is most restricted.

The output signal generating unit 35 generates a PWM (Pulse Wide Modulation) signal for controlling the pilot pressure control valve 21 based on the degree of restriction set by the restriction degree setting unit 34, and outputs the PWM signal to the pilot pressure control valve 21. The output signal generating unit 35 also generates an engine speed command value based on the degree of restriction set by the restriction degree setting unit 34, and outputs the engine speed command value to the engine controller 17.

Figure 5 shows the engine speed command value output from the output signal generating unit 35 according to the degree of restriction of the actuator, and the control of the pilot pressure control valve 21 by the output signal generating unit 35 according to the degree of restriction. As shown in Figure 5, the output signal generating unit 35 sets the engine speed command value to the heavy speed when the degree of restriction is "heavy", sets the engine speed command value to the medium speed when the degree of restriction is "moderate", and sets the engine speed command value to the light speed when the degree of restriction is "light", and outputs an engine speed reduction command to the engine controller 17. Note that the magnitude relationship between the respective speeds is heavy engine speed < medium engine speed < light engine speed.

The light engine speed, the medium engine speed, and the heavy engine speed are each smaller than the engine speed command value corresponding to the amount of operation of the engine control dial 26. The light engine speed, the medium engine speed, and the heavy engine speed are calculated, for example, by multiplying the engine speed command value corresponding to the amount of operation of the engine control dial 26 by a predetermined constant ce (0<ce<1).

The output signal generating unit 35 controls the pilot pressure control valve 21 in a shutoff manner according to the degree of restriction. When the degree of restriction is "severe", the output signal generating unit 35 executes sudden stop control by the pilot pressure control valve 21. When the degree of restriction is "medium", the output signal generating unit 35 executes slow stop control by the pilot pressure control valve 21. When the degree of restriction is "light", the output signal generating unit 35 executes start inhibition control by the pilot pressure control valve 21.

The sudden stop control refers to controlling the pilot pressure control valve 21 to stop the operation of the travel motors 19L, 19R and the swing motor 20. The gradual stop control refers to controlling the pilot pressure control valve 21 to stop the operation of the travel motors 19L, 19R and the swing motor 20 more gradually than in the sudden stop control. The start inhibition control refers to controlling the pilot pressure control valve 21 to maintain the stopped state of the travel motors 19L, 19R and the swing motor 20 without stopping the operation of the travel motors 19L, 19R and the swing motor 20 when they are stopped.

The main operations in this embodiment will be described. The case will be described where the severe threshold is set to 30% and the moderate threshold is set to 60%. For example, as shown in FIG. 4, worker C with worker ID 003 has entered the work area four times, and of those four times, he entered the work area in compliance with the rules once. Therefore, the rule compliance level of worker C is 25% (= 1 [time] / 4 [times] x 100). When worker C enters the work area without complying with the rules, the vehicle control controller 120 updates the total number of intrusions of worker C with worker ID 003 to 5 [times] in the intrusion history information stored in the non-volatile memory 122, and updates the rule compliance level to 20% (= 1 [time] / 5 [times] x 100).

The vehicle body controller 120 refers to the intrusion history information, determines that the rule compliance level (20%) of the worker C with the worker ID 003 is equal to or lower than the severe threshold (30%), and sets the degree of restriction to severe. The vehicle body controller 120 sets the engine speed command value to the severe speed and executes emergency stop control using the pilot pressure control valve 21. Therefore, if the worker C with the worker ID 003 intrudes into the working range while the hydraulic excavator 100 is swinging, the swing motor 20 immediately decelerates and stops. This makes it possible to prevent contact between the worker C and the hydraulic excavator 100.

For example, worker D with worker ID 004 has entered the work area 27 times, of which 12 times were in compliance with the rules. Therefore, the rule compliance level of worker D is 44% (= 12 times / 27 times x 100). When worker D enters the work area in compliance with the rules, the vehicle control controller 120 updates the total number of intrusions of worker D with worker ID 004 to 28 times, the number of appropriate intrusions to 13 times, and the rule compliance level to 46% (= 13 times / 28 times x 100) in the intrusion history information stored in the non-volatile memory 122.

The vehicle body controller 120 refers to the intrusion history information, determines that the rule compliance level (46%) of the worker D with the worker ID 004 is greater than the severe threshold (30%) and equal to or less than the moderate threshold (60%), and sets the degree of restriction to moderate. The vehicle body controller 120 sets the engine speed command value to a moderate speed and executes a slow stop control by the pilot pressure control valve 21. Therefore, if the worker D with the worker ID 004 intrudes into the working range while the hydraulic excavator 100 is swinging, the swing motor 20 decelerates and stops. This makes it possible to prevent contact between the worker D and the hydraulic excavator 100.

For example, worker E with worker ID 005 has entered the work area 24 times, of which 20 times were in compliance with the rules. Therefore, worker E's rule compliance level is 83% (= 20 times / 24 times x 100). If worker E enters the work area without complying with the rules, the vehicle control controller 120 updates the total number of intrusions of worker E with worker ID 005 to 25 times in the intrusion history information stored in the non-volatile memory 122, and updates the rule compliance level to 80% (= 20 times / 25 times x 100).

The vehicle body controller 120 refers to the intrusion history information, determines that the rule compliance level (80%) of the worker E with the worker ID 005 is greater than the medium threshold (60%), and sets the degree of restriction to light. The vehicle body controller 120 sets the engine speed command value to light speed and executes start suppression control by the pilot pressure control valve 21. Therefore, even if a swing operation is performed when the hydraulic excavator 100 is stopped, the swing motor 20 remains stopped.

Because worker E has a high degree of compliance with rules, it is believed that he entered the working range while knowing that the hydraulic excavator 100 was in a workable state. For this reason, the vehicle control controller 120 does not perform slow stop control or sudden stop control. This makes it possible to prevent a decrease in the efficiency of work by the hydraulic excavator 100 due to worker E's intrusion into the working range. Note that if worker E with worker ID 005 enters the working range while the hydraulic excavator 100 is rotating, the engine speed is reduced to decelerate the swing motor 20. In addition, the alarm device 22 notifies the operator and worker E that worker E has entered the working range. This prevents contact between worker E and the hydraulic excavator 100.

The above-described embodiment provides the following effects:

(1) A work machine control system 1 includes an RFID tag (wireless terminal) 4 carried by a worker (person), and a vehicle control controller (control device) 120 that performs control to limit the operation of the actuators (travel motors 19L, 19R, swing motor 20) of the hydraulic excavator 100 when it detects the intrusion of the worker into the working area of the hydraulic excavator (work machine) 100 based on a signal transmitted from the RFID tag 4. The vehicle control controller 120 determines whether the worker has intruded into the working area in compliance with predetermined rules based on the state of the hydraulic excavator 1, stores information that associates the determination result with the identification information of the worker (worker ID) as intrusion history information, and calculates a degree of rule compliance that indicates the degree to which the worker has intruded into the working area in compliance with the rules based on the intrusion history information. When the vehicle body controller 120 detects the intrusion of a worker into the work area, it controls the operation of the actuator so that if the worker who has intruded into the work area has a high degree of rule compliance, the actuator operation is restricted to a smaller extent than if the worker has a low degree of rule compliance.

In this way, in this embodiment, the behavior of the worker when he/she enters the working range of the hydraulic excavator 100 is stored and collected, and the degree of compliance with rules of the worker, which is difficult to measure only by the worker's experience, proficiency, and abilities (including safety qualification information), can be quantified. By utilizing the degree of compliance with rules of the worker, the degree of restriction on the operation of the hydraulic excavator 100 can be appropriately adjusted even when it is difficult to distinguish the abilities of the workers (when there is no qualified person at the work site and when an uncommon unique certification system is established). Therefore, according to this embodiment, it is possible to provide a work machine control system 1 that can appropriately restrict the operation of the hydraulic excavator 100 depending on the worker who has entered the working range of the hydraulic excavator 100. As a result, it is possible to improve work efficiency while preventing contact between the hydraulic excavator 100 and the worker. In other words, it is possible to achieve both productivity and safety at the work site.

(2) In addition, in this embodiment, the behavior of the worker can be recorded, including inappropriate intrusions caused by familiarity due to the worker being an expert. This leads to improved safety awareness among workers.

(3) The rule is that when the hydraulic excavator 100 is in a workable state, entry into the working range is prohibited, and when the hydraulic excavator 100 is in a workable state, entry into the working range is permitted. As a result, when a worker enters the working range, the degree of restriction can be appropriately adjusted based on the ratio of the total number of times the worker has entered the working range to the number of times the worker has entered the working range when the workable state was in (degree of compliance with the rules).

Second Embodiment
A work machine control system 1 according to a second embodiment of the present invention will be described with reference to Fig. 6. In the figure, the same reference numbers are used for parts that are the same as or equivalent to those in the first embodiment, and differences will be mainly described. In the first embodiment, an example was described in which the severe threshold and the moderate threshold are constants. In contrast, in the second embodiment, the severe threshold and the moderate threshold are variables that change depending on the total number of intrusions.

Figure 6 is a diagram showing the threshold table stored in the non-volatile memory 122. The threshold table is a data table that stores the relationship between the total number of intrusions and the degree of compliance with rules. The threshold table stores characteristics of a severe threshold and characteristics of a medium threshold. The characteristics of the severe threshold are a value Ts1 when the total number of intrusions is 0, and the value becomes smaller as the total number of intrusions increases. The characteristics of the medium threshold are a value Tm1 when the total number of intrusions is 0, and the value becomes smaller as the total number of intrusions increases. The magnitude relationship between values Ts1 and Tm1 is Ts1 < Tm1.

When the total number of intrusions reaches a predetermined number (first number) or more, the severe threshold becomes the lower limit. The severe threshold lower limit may be 0 [%] or a predetermined value (first lower limit). Similarly, when the total number of intrusions reaches a predetermined number (second number) or more, the moderate threshold becomes the moderate threshold lower limit. The moderate threshold lower limit may be 0 [%] or a predetermined value (second lower limit). The magnitude relationship between the first lower limit and the second lower limit is preferably first lower limit <= second lower limit.

In the second embodiment, when a worker enters the working area, the restriction degree setting unit 34 refers to the threshold table (see FIG. 6) and determines a severe threshold and a medium threshold based on the total number of intrusions read from the intrusion history information (see FIG. 4). The restriction degree setting unit 34 compares the degree of compliance with the rules read from the intrusion history information (see FIG. 4) with the severe threshold and the medium threshold, and sets the degree of restriction on the actuator operation based on the comparison result.

With this configuration, the degree of restriction on the actuator changes depending on the total number of intrusions even if the degree of rule compliance is the same. With reference to FIG. 6, for example, a case will be described where an unskilled worker F and a skilled worker G intrude into the work area. The total number of intrusions for worker F is Nf, the degree of rule compliance is Rf, the total number of intrusions for worker G is Ng, the degree of rule compliance is Rg, where Rf=Rg and Nf<Ng. In this case, when worker G intrudes into the work area, the vehicle body control controller 120 sets the degree of restriction on the actuator operation to "medium". On the other hand, when worker F intrudes into the work area, the vehicle body control controller 120 sets the degree of restriction on the actuator operation to "severe".

In this way, the vehicle body control controller (control device) 120 according to the second embodiment controls the operation of the actuators (travel motors 19L, 19R, swing motor 20) so that when the worker who has entered the work area is worker F, who has a low total number of intrusions, the degree of restriction on the operation of the actuators is greater than when the worker who has entered the work area is worker G, who has a high total number of intrusions.

Therefore, according to the second embodiment, in addition to the same effects as the first embodiment, the following action and effect is achieved. When the number of times the worker enters the working area is low, i.e., when the worker's level of proficiency is low, the degree of restriction on the actuator operation is higher than when the level of proficiency is high. In other words, according to the second embodiment, the actuator operation can be appropriately restricted according to the worker's level of proficiency.

<Modification of the second embodiment>
In the second embodiment, an example has been described in which the severe threshold and the moderate threshold linearly decrease with an increase in the total number of intrusions in a range in which the total number of intrusions is equal to or greater than 0, but the present invention is not limited to this.

A worker who has entered the work range only a very small number of times is expected to be an unskilled worker. Therefore, in this modified example, as shown in FIG. 7, the restriction degree setting unit 34 sets the severe threshold and the medium threshold to 100% if the total number of times the worker has entered the work range is equal to or less than the predetermined number N0. Therefore, if the total number of times the worker has entered the work range is equal to or less than the predetermined number N0, the actuator restriction degree is set to "severe" regardless of the degree of compliance with the rules.

In this way, when a worker who has entered the working area has a total intrusion count less than the predetermined number N0, the vehicle body control controller (control device) 120 according to this modified example controls the operation of the actuator at the "severe" level of restriction, which is the same as that for a worker whose total intrusion count is greater than the predetermined number N0 and whose rule compliance level is the lowest (rule compliance level = 0%), regardless of the rule compliance level. Therefore, when a worker with little work experience enters the working area, contact between the hydraulic excavator 100 and the worker can be reliably avoided.

Third Embodiment
A construction machine control system 1C according to a third embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a diagram showing the configuration of the construction machine control system 1C according to the third embodiment. As shown in Fig. 8, in this third embodiment, an example will be described in which the construction machine is a wheel loader 200. The construction machine control system 1C has the wheel loader 200 and an RFID tag 4B, which is a wireless terminal carried by a worker (person) performing work around the wheel loader 200.

The wheel loader 200 comprises a vehicle body 204 on which a traveling device 202 is mounted, and an articulated working device 210 attached to the front of the vehicle body 204. The vehicle body 204 is an articulated steering type (body articulation type) vehicle body, and has a front vehicle body 204A, a rear vehicle body 204B, and a center joint 203 that connects the front vehicle body 204A and the rear vehicle body 204B. A driver's cab 207 is provided at the front and an engine room 206 is provided at the rear on the rear vehicle body 204B. The engine room 206 houses an engine 280 and hydraulic equipment such as a hydraulic pump driven by the engine 280. The working device 210 and the traveling device 202 are driven independently of each other by the power of the engine 280. The engine 280 is, for example, an internal combustion engine such as a diesel engine.

The working device 210 is attached to the front vehicle body 204A. The working device 210 has a lift arm (hereinafter simply referred to as the arm) 211 that is rotatably attached to the front vehicle body 204A, and a bucket 213 that is rotatably attached to the arm 211. The arm 211 is moved in response to the extension and retraction of an arm cylinder 211a, which is a hydraulic cylinder, and the bucket 213 is moved in response to the extension and retraction of a bucket cylinder 213a, which is a hydraulic cylinder.

The traveling device 202 has front wheels (front wheels) attached to the front body 204A, rear wheels (rear wheels) attached to the rear body 204B, and a power transmission device that transmits the power of the engine 280 to the wheels. The power transmission device is composed of an axle, a differential device, a propeller shaft, etc.

The wheel loader 200 has steering cylinders 216, which are a pair of left and right hydraulic cylinders that are provided to connect the front body 204A and the rear body 204B. The wheel loader 200 is steered by adjusting the amount of extension and retraction of the left and right steering cylinders 216. The hydraulic cylinders (211a, 213a, 216), which are actuators, extend and retract using hydraulic oil (pressurized oil) discharged from a hydraulic pump that rotates due to the torque output by the engine 280.

The wheel loader 200 is equipped with a vehicle body controller 220, which is a control device that controls the engine 280, hydraulic pump, control valves, etc., mounted on the vehicle body 204. The vehicle body controller 220, like the vehicle body controller 120 mounted on the hydraulic excavator 100, is composed of a computer equipped with a processor, non-volatile memory, volatile memory, an input/output interface, and other peripheral circuits.

Figure 9A is a top view of the wheel loader 200, showing the working area when the wheel loader 200 is stopped (the area shown by hatching in the figure). Figure 9B is a top view of the wheel loader 200, showing the working area when the wheel loader 200 is traveling (the area shown by hatching in the figure).

The vehicle body controller 220 determines whether the wheel loader 200 is stopped or moving. The determination of whether the wheel loader 200 is stopped or moving may be made based on the detection value of a vehicle speed sensor provided on the wheel loader 200, or based on the operating position of a forward/reverse switching device provided on the wheel loader 200, or based on the operating position of an operating member that operates a parking brake device provided on the wheel loader 200.

For example, the vehicle body control controller 220 determines that the wheel loader 200 is stopped when the vehicle speed detected by the vehicle speed sensor is less than a threshold value, and determines that the wheel loader 200 is traveling when the vehicle speed detected by the vehicle speed sensor is equal to or greater than the threshold value. The vehicle body control controller 220 may also determine that the wheel loader 200 is stopped when the operation position of the forward/reverse switching device is in the neutral position, and determine that the wheel loader 200 is traveling when the operation position of the forward/reverse switching device is in the forward position or reverse position. Furthermore, the vehicle body control controller 220 may determine that the wheel loader 200 is stopped when the operation member of the parking brake device is in an operation position that activates the parking brake device, and determine that the wheel loader 200 is traveling when the operation member of the parking brake device is in an operation position that releases the operation of the parking brake device.

When the vehicle body controller 220 determines that the wheel loader 200 is stopped, it sets the working range as shown in FIG. 9A. This working range corresponds to the maximum range in which the wheel loader 200 can be bent by extending and retracting the steering cylinder 216 while the wheel loader 200 is stopped.

When the vehicle body controller 220 determines that the wheel loader 200 is traveling, it sets a working range as shown in FIG. 9B. This working range corresponds to the area that the wheel loader 200 can reach within a specified time while the wheel loader 200 is traveling. The vehicle body controller 220 calculates the reachable distance based on the vehicle speed detected by the vehicle speed sensor and the specified time stored in the non-volatile memory, and sets a roughly arc-shaped working range with the reachable distance as a radius in both the front and rear directions.

In this embodiment, the vehicle body controller 220 sets the working ranges to the front and rear of the vehicle body 204 regardless of the traveling direction of the wheel loader 200, but the present invention is not limited to this. It is possible to determine whether the traveling direction of the wheel loader 200 is forward or reverse based on the operating position of the forward/reverse switching device that determines the traveling direction of the wheel loader 200, and to set only one of the working ranges in front of the vehicle body 204 or the working range in the rear of the vehicle body 204 based on the determination result.

Similar to the vehicle body control controller 120 described in the first embodiment, when a worker enters the work area, the vehicle body control controller 220 sets the degree of restriction on the actuator operation based on the worker's compliance with the rules. In this second embodiment, the vehicle body control controller 220 outputs an engine speed reduction command to the engine controller according to the set degree of restriction. This reduces the engine speed and restricts the actuator operation.

In addition to reducing the engine speed, the vehicle body controller 220 may also control a pilot pressure control valve that can reduce the pilot pressure (operating pressure) that is led to the pressure receiving part of the flow control valve that controls the steering cylinder 216. In this case, the vehicle body controller 220 may limit the operation of the steering cylinder 216 by controlling this pilot pressure control valve to reduce the pilot pressure (operating pressure) that is led to the pressure receiving part. Note that it is preferable to limit the operation of the steering cylinder 216 only when the vehicle is stopped, since limiting the operation of the steering cylinder 216 while the vehicle is moving may interfere with avoidance operations.

Furthermore, if the traveling device 202 is equipped with a traveling motor, the operation of the wheel loader 200 may be restricted by restricting the rotation of the traveling motor.

In this embodiment, the working range varies depending on the vehicle speed of the wheel loader 200. For this reason, the RFID tag 4B has not only a function for detecting the magnetic field generated by the magnetic field generating device 61 provided in the wheel loader 200, but also a function for acquiring a three-dimensional position calculation value (position information) by GNSS (Global Navigation Satellite System). Similarly, the wheel loader 200 also has a function for acquiring a three-dimensional position calculation value (position information) by GNSS. The vehicle body control controller 220 of the wheel loader 200 calculates a detailed positional relationship between the wheel loader 200 and the RFID tag 4B using the position information of the vehicle itself and the position information from the RFID tag 4B. As a result, the vehicle body control controller 220 can appropriately detect whether or not a worker has entered the working range even if the working range has changed.

Fourth Embodiment
A construction machine control system 1D according to a fourth embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is a diagram showing the configuration of a construction machine control system 1D according to the fourth embodiment of the present invention. In the figure, the same reference numbers are used for parts that are the same as or equivalent to those in the first embodiment, and differences will be mainly described.

As shown in FIG. 10, the construction machine control system 1D according to the fourth embodiment includes an RFID tag 4 carried by an operator, a hydraulic excavator 100 equipped with a vehicle body control controller 120, a wheel loader 200 equipped with a vehicle body control controller 220, and a server 320 provided in equipment external to the hydraulic excavator 100 and the wheel loader 200.

In the fourth embodiment, an example in which two work machines are operating at a work site will be described, but the present invention can also be applied to cases in which three or more work machines are operating at a work site. The server 320 can send and receive data to and from multiple work machines (hydraulic excavator 100 and wheel loader 200) via a communication line 41, which is a wide area network, using a communication device. The communication line 41 is a mobile phone communication network (mobile communication network) provided by a mobile phone carrier or the like, the Internet, etc.

Similar to the vehicle body controller 120, the server 320 is composed of a computer equipped with a processor, non-volatile memory 322, volatile memory, an input/output interface, and other peripheral circuits. The server 320 collects intrusion history information transmitted from multiple work machines and stores it in an intrusion history database in the non-volatile memory 322.

The intrusion history database in the non-volatile memory 322 stores the worker ID of the worker who has intruded into the working range of the hydraulic excavator 100, the total number of intrusions, and the number of appropriate intrusions, as well as the worker ID of the worker who has intruded into the working range of the wheel loader 200, the total number of intrusions, and the number of appropriate intrusions.

At a work site, multiple work machines are working. For this reason, at a work site, a single worker may enter the working range of multiple work machines. For example, the non-volatile memory 122 of the vehicle body control controller 120 of the hydraulic excavator 100 stores that the total number of intrusions for worker H with worker ID 008 is 10, and the number of appropriate intrusions is 3. Furthermore, the non-volatile memory 222 of the vehicle body control controller 220 of the wheel loader 200 stores that the total number of intrusions for worker H with worker ID 008 is 6, and the number of appropriate intrusions is 5.

In the intrusion history database of the non-volatile memory 322 of the server 320, the sum of the total number of intrusions by worker H transmitted from the hydraulic excavator 100 and the total number of intrusions by worker H transmitted from the wheel loader 200 is stored as the total number of intrusions by worker H (16 times in the illustrated example). In addition, in the intrusion history database of the non-volatile memory 322 of the server 320, the sum of the appropriate number of intrusions by worker H transmitted from the hydraulic excavator 100 and the appropriate number of intrusions by worker H transmitted from the wheel loader 200 is stored as the appropriate number of intrusions by worker H (8 times in the illustrated example).

When the intrusion history information of the work machine is updated and the server 320 acquires the updated information, it updates the intrusion history database in the non-volatile memory 322. For example, when the total number of intrusions and the number of appropriate intrusions of worker H with worker ID 008 stored in the non-volatile memory 122 of the vehicle body control controller 120 of the hydraulic excavator 100 are each increased by 1, the total number of intrusions and the number of appropriate intrusions of worker H with worker ID 008 in the intrusion history database of the server 320 are each increased by 1.

When the total number of intrusions by worker H is updated, the server 320 calculates the ratio of the number of appropriate intrusions to the total number of intrusions as the degree of compliance with the rules, and updates the degree of compliance with the rules in the intrusion history database in the non-volatile memory 322. When the server 320 updates the degree of compliance with the rules by worker H, it transmits the updated degree of compliance with the rules to the hydraulic excavator 100 via the communication line 41.

The vehicle body controller 120 of the hydraulic excavator 100 sets the degree of restriction on the actuator operation based on the received degree of compliance with the rules. The method for setting the degree of restriction on the actuator operation is the same as in the first embodiment described above, so a description thereof will be omitted.

As described above, the work machine control system 1D according to the fourth embodiment is configured to enable two-way communication between multiple work machines (hydraulic excavator 100, wheel loader 200) and the server 320 via the communication line 41.

The control system 1D also has, as control devices, vehicle body controllers 120, 220 mounted on the work machines and a server 320 provided outside the work machines. The server 320 collects worker intrusion history information transmitted from a plurality of work machines. When a worker who has intruded into the work area has a high degree of rule compliance obtained from the worker intrusion history information collected by the server 320, the vehicle body controllers 120, 220 control the operation of the actuator so that the degree of restriction on the actuator operation is smaller than when the worker has a low degree of rule compliance.

According to this fourth embodiment, the degree of worker compliance with rules can be quantified for the entire work site, regardless of a specific work machine. Therefore, for example, for a work machine that has been newly introduced to a work site or a work machine with a low operating rate, it is possible to appropriately restrict the operation of the work machine by using the already quantified degree of worker compliance with rules.

<Modification of the Fourth Embodiment>
In the fourth embodiment, an example has been described in which the server 320 calculates the degree of compliance with the rules and transmits the calculation result to the work machine, but the present invention is not limited to this. The server 320 may transmit the total number of intrusions and the appropriate number of intrusions, which are intrusion history information collected from a plurality of work machines, to the work machine, and the vehicle body controller 120, 220 mounted on the work machine may calculate the degree of compliance with the rules based on the total number of intrusions and the appropriate number of intrusions acquired from the server 320. Even in such a case, the same effects as those of the fourth embodiment described above can be achieved.

The following modified examples are also within the scope of the present invention, and it is possible to combine the configurations shown in the modified examples with the configurations described in the above-mentioned embodiments, to combine the configurations described in the different embodiments above, or to combine the configurations described in the different modified examples below.

<Modification 1>
In the first embodiment, an example has been described in which the vehicle body control controller 120, 220 determines whether or not a person has entered the working range in compliance with a predetermined rule based on the state of the work machine. Also, an example has been described in which the rule prohibits entry into the working range when the state of the work machine is in a workable state, and permits entry into the working range when the state of the work machine is in a workable state. However, the present invention is not limited to this. The vehicle body control controller 120, 220 may determine whether or not a person has entered the working range in compliance with a predetermined rule based on at least one of the state of the work machine and the state of the person.

<Modification 1-1>
For example, the rule may be such that a person is prohibited from entering the work area when the person is not carrying a predetermined personal item, and is permitted to enter the work area when the person is carrying the personal item, such as a helmet, high visibility safety clothing with reflective material, etc.

Modification 1-1 of the first embodiment will be described with reference to FIG. 11. FIG. 11 is a functional block diagram relating to the operation restriction control by the vehicle control controller 120A in the work machine control system according to modification 1-1. The hydraulic excavator 100 is equipped with a plurality of image capture devices 90 that capture images of the surroundings of the hydraulic excavator 100. The vehicle control controller 120A has a possession determination unit 91 that determines whether or not the worker is carrying predetermined possessions based on images captured by the image capture devices 90.

The image capturing device 90 is, for example, a wide-angle video camera equipped with a durable, weather-resistant image capturing element such as a CCD or CMOS, and a wide-angle lens. Multiple image capturing devices 90 are attached to the hydraulic excavator 100. The vehicle body controller 120A monitors the working range of the hydraulic excavator 100 using the multiple image capturing devices 90.

The belongings determination unit 91 acquires image data captured by the imaging device 90, and recognizes the presence of belongings in the image from the acquired image data through recognition processing using a well-known recognition model (e.g., the YOLO model). The belongings determination unit 91 determines whether the reliability of the result of the recognition processing on the image data is equal to or greater than a reliability threshold. If the belongings determination unit 91 determines that the reliability of the result of the recognition processing is equal to or greater than the reliability threshold, it determines that belongings are present within the working area. If the belongings determination unit 91 determines that the reliability of the result of the recognition processing on the image data is less than the reliability threshold, it determines that belongings are not present within the working area.

The reliability is a judgment output value obtained by the recognition process of the belongings judgment unit 91, and corresponds to the degree of match with the object parameters preset in the recognition model, and is 100% in the case of perfect match. The reliability threshold is a threshold value that is preset to judge the presence or absence of belongings.

When the worker ID of a worker present within the work range is input from the worker detection device 60 and the belongings determination unit 91 determines that belongings are present within the work range, the rule compliance determination unit 32A determines that the worker who has entered the work range is in a state of carrying predetermined belongings. In other words, the rule compliance determination unit 32A determines that the worker has entered the work range in compliance with the rules. When the worker ID of a worker present within the work range is input from the worker detection device 60 and the belongings determination unit 91 determines that no belongings are present within the work range, the rule compliance determination unit 32A determines that the worker who has entered the work range is in a state of not carrying predetermined belongings. In other words, the rule compliance determination unit 32A determines that the worker has entered the work range without complying with the rules.

This modification provides the same effects as the first embodiment.

In this modified example 1-1, an example has been described in which the vehicle body control controller 120A executes recognition processing of the worker's belongings based on the image captured by the image capture device 90, but the present invention is not limited to this. An infrared sensor may be provided instead of the image capture device 90, and the vehicle body control controller 120A may execute recognition processing of the worker's belongings based on the detection results of the infrared sensor.

<Modification 1-2>
The rule may be such that when there is only one person, entry into the working area is prohibited, and when there are two or more people, entry into the working area is permitted.

A modified example 1-2 of the first embodiment will be described with reference to FIG. 12. FIG. 12 is a functional block diagram relating to the operation restriction control by the vehicle control controller 120B in the control system for the work machine according to the modified example 1-2. The rule compliance determination unit 32B starts measuring time when the worker detection device 60 detects that one worker (e.g., worker J) has entered the work area. The rule compliance determination unit 32B determines whether the worker detection device 60 has detected that another worker (e.g., worker K) has entered the work area before the measured time t reaches a predetermined time threshold t0.

If the worker detection device 60 detects that another worker (e.g., worker K) has entered the work area before the measured time t has passed the time threshold t0, the rule compliance determination unit 32B determines that the number of workers who have entered the work area is two or more. In other words, the rule compliance determination unit 32B determines that two workers (e.g., workers J and K) have entered the work area in compliance with the rules. If the measured time t has passed the time threshold t0 without the worker detection device 60 detecting that another worker has entered the work area, the rule compliance determination unit 32 determines that the number of workers who have entered the work area is one. In other words, the rule compliance determination unit 32B determines that the worker who has entered the work area (e.g., worker J) has entered the work area without complying with the rules.

In addition, if the worker detection device 60 detects that a worker (e.g., worker J) has left the work area before the measured time t has reached the time threshold t0, the rule compliance determination unit 32B determines that the worker (e.g., worker J) has entered the work area without complying with the rules.

When two workers are present within the working area, the restriction degree setting unit 34B selects the lower of the two workers' rule compliance degrees and sets the degree of restriction on the actuator operation based on the selected rule compliance degree.

This modification provides the same effects as the first embodiment.

<Modification 1-3>
The rules described in the first embodiment and modified examples 1-1 and 1-2 may be used in combination. For example, the rule may be such that when the work machine is in a workable state or when the worker is not carrying a predetermined personal item, entry into the work area is prohibited, and when the work machine is in a workable state and the worker is carrying a personal item, entry into the work area is permitted.

<Modification 2>
The configuration described in the first embodiment may be combined with the configuration described in the modified example of the second embodiment. That is, in the first embodiment, when the total number of intrusions by a person into the working area is equal to or less than a predetermined number N0, the vehicle body controller 120 may control the operation of the actuator to "serious" regardless of the degree of compliance with the rules.

<Modification 3>
In the second embodiment, an example has been described in which the characteristics of the severe threshold and the medium threshold change linearly according to the total number of intrusions as shown in Fig. 6, but the present invention is not limited to this. The characteristics of the severe threshold and the medium threshold may change in a curved manner.

<Modification 4>
In the above embodiment, an example has been described in which the degree of restriction of the actuator is in three stages ("heavy", "medium", and "light"), but the present invention is not limited to this. The degree of restriction may be in two stages, or may be in four or more stages.

<Modification 5>
The operation restriction modes described in the first and second embodiments are merely examples, and may be changed according to the type of hydraulic excavator 100, the work operation, and the like. For example, as an operation restriction mode in the first embodiment, the engine speed may be reduced, and the operation pressure led to the pressure receiving portion of the flow control valve corresponding to the actuator (111a, 112a, 113a) of the work device 110 may be reduced or cut off by the pilot pressure control valve 21, thereby slowing down or stopping the operation of the work device 110. In addition, the operation of the hydraulic actuator may be restricted by reducing the discharge capacity (displacement volume) of the hydraulic pump. Note that the operation of the actuator may be restricted only by reducing the engine speed, or only by reducing the operation pressure by the pilot pressure control valve 21.

<Modification 6>
In the above embodiment, an example has been described in which the rule compliance level is the ratio of the number of appropriate intrusions to the total number of intrusions, but the present invention is not limited to this. The rule compliance level may be a value that represents the degree to which a worker intrudes into the work area while complying with the rules. For example, the rule compliance level may be a value that takes into account a weight for a specific worker.

<Modification 7>
In the first embodiment, an example in which the working range of the hydraulic excavator 100 is constant has been described, but the present invention is not limited to this. The working range may be changed according to the posture of the working device 110. In this case, the detection control device 63 adjusts the strength of the magnetic field generated by the magnetic field generating device 61 so that a magnetic field detectable area 69 is formed that includes the working range that changes according to the posture of the working device 110. Note that the RFID tag 4 and the hydraulic excavator 100 may be provided with a function of acquiring a three-dimensional position calculation value (position information) by GNSS. In this case, the vehicle body control controller 120 determines whether the RFID tag 4 is present within the working range of the hydraulic excavator 100 based on the positional relationship between the RFID tag 4 and the hydraulic excavator 100.

<Modification 8>
In the first and second embodiments, an example is described in which the work machine is a crawler-type hydraulic excavator 100, and in the third embodiment, an example is described in which the work machine is a wheel loader 200, but the present invention is not limited to this. The work machine may be a wheel-type hydraulic excavator, road machinery, a crawler crane, etc.

<Modification 9>
In the above embodiment, an example has been described in which the wireless terminal carried by the worker is an RFID tag, but the present invention is not limited to this. The wireless terminal may be a smartphone or the like that is capable of acquiring a three-dimensional position calculation value (position information) by GNSS and transmitting the acquired position information and identification information of the worker to the work machine.

Although the embodiments of the present invention have been described above, the above embodiments merely show some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

1, 1C, 1D...control system, 4, 4B...RFID tag (wireless terminal), 11...main pump, 12...pilot pump, 13...control valve, 14...operation device, 15...operation pressure sensor, 18...gate lock device, 19L, 19R...travel motor (actuator), 20...swing motor (actuator), 21...pilot pressure control valve, 25...gate lock solenoid valve, 31...status management unit, 32, 32A, 32B...rule compliance determination unit, 33...intrusion history memory unit, 34, 34B...restriction level setting unit, 35...output signal generation unit, 60...worker detection device, 80...engine, 90...photography device, 91...possession determination unit, 100...hydraulic excavator (work machine), 102...traveling body, 103...swinging body, 110...working device , 111a... boom cylinder (actuator), 112a... arm cylinder (actuator), 113a... bucket cylinder (actuator), 120, 120A, 120B... vehicle control controller (control device), 122... non-volatile memory, 200... wheel loader (working machine), 202... running gear, 204... vehicle body, 204A... front vehicle body, 204B... rear vehicle body, 210... working gear, 211a... arm cylinder (actuator), 213a... bucket cylinder (actuator), 216... steering cylinder (actuator), 220... vehicle control controller (control device), 222... non-volatile memory, 280... engine, 320... server (control device), 322... non-volatile memory

Claims (9)

A control system for a work machine including a wireless terminal carried by a person and a control device that performs control to limit operation of an actuator of the work machine when intrusion of the person into a working range of the work machine is detected based on a signal transmitted from the wireless terminal,
The control device includes:
determining whether or not the person has entered the working range in compliance with a predetermined rule based on at least one of the state of the work machine and the state of the person, and storing information correlating the determination result with identification information of the person as intrusion history information;
calculating a rule compliance degree representing the degree to which the person has intruded into the work area in compliance with the rule based on the intrusion history information;
a control system for a work machine, characterized in that, when intrusion of a person into the working range is detected, if the person who has intruded into the working range has a high degree of compliance with rules, the operation of the actuator is controlled so that the degree of restriction on the operation of the actuator is reduced compared to when the degree of compliance with rules is low. 2. The work machine control system according to claim 1,
the control device calculates, as the degree of rule compliance, a ratio of the number of times the person has entered the work range in compliance with the rules to a total number of intrusions, which is the sum of the number of times the person has entered the work range. 3. The control system for a work machine according to claim 2,
a control system for a work machine, characterized in that the rule is a rule that prohibits entry into the working range when the state of the work machine is in a workable state, and permits entry into the working range when the state of the work machine is in a workable state. 4. The control system for a work machine according to claim 3,
The work machine includes:
An operating device that commands the operation of the actuator;
a locking device that is switchable between a state in which the actuator can be operated by the operating device and a state in which the actuator cannot be operated by the operating device,
The control device determines that the state of the work machine is in a workable state when the locking device has enabled the actuator to operate, and determines that the state of the work machine is in a work-disabled state when the locking device has disabled the actuator to operate.
A work machine control system comprising: 3. The control system for a work machine according to claim 2,
The control device includes:
a control system for a work machine, characterized in that when a person who has intruded into the working range has a small total number of intrusions, the operation of the actuator is controlled so that the degree of restriction on the operation of the actuator is greater than when a person who has intruded into the working range has a large total number of intrusions. 3. The control system for a work machine according to claim 2,
The control device includes:
a control system for a work machine, characterized in that, when a person who has intruded into the working range has a total number of intrusions equal to or less than a predetermined number, the operation of the actuator is controlled with the same degree of restriction as a person whose total number of intrusions is greater than the predetermined number and whose degree of rule compliance is the lowest, regardless of the degree of rule compliance. 2. The work machine control system according to claim 1,
The rule prohibits the person from entering the work area when the person's state is a state in which the person is not carrying a predetermined personal item, and permits the person from entering the work area when the person's state is a state in which the person is carrying the personal item. 2. The work machine control system according to claim 1,
The control system for a work machine, wherein the rule prohibits entry into the working area when there is only one person, and permits entry into the working area when there are two or more people. 2. The work machine control system according to claim 1,
The control device includes a vehicle body control controller mounted on the work machine and a server provided outside the work machine,
The server collects the intrusion history information of the person transmitted from a plurality of the work machines,
The vehicle body controller controls the operation of the actuator so that, when a person who has entered the working range has a high level of rule compliance obtained from the person's intrusion history information collected by the server, the degree of restriction on the operation of the actuator is reduced compared to when the person has a low level of rule compliance.

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