Excavator and work monitoring system

Abstract

To provide a shovel that enables an operator in a cab to more accurately check his / her condition. [Solution] The excavator 100 has a lower running body 1, an upper rotating body 3 rotatably mounted on the lower running body 1, a cabin 10 mounted on the upper rotating body 3, a left operating lever 26AL located on the left side of the driver's seat 110 within the cabin 10, a right operating lever 26AR located on the right side of the driver's seat 110 within the cabin 10, an imaging device attached within the cabin 10 that captures images of at least the left operating lever 26AL, the right operating lever 26AR, and the torso of the operator seated in the driver's seat 110 so as to include within the imaging range, and a controller 30 into which images captured by the imaging device are input.

Description

[Technical Field]

[0001] The present disclosure relates to an excavator and a work monitoring system. [Background technology]

[0002] BACKGROUND ART There is known an excavator that determines the state of an operator based on a change in the distribution of pressure applied to the seat surface of a driver's seat installed in a cabin (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-162225 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the above-described excavator determines the state of the operator based only on the distribution of pressure applied to the seat surface of the driver's seat, there is a risk that the state of the operator in the driver's cab cannot be accurately confirmed.

[0005] Therefore, it is desirable to provide a shovel that allows the operator's condition in the cab to be more accurately confirmed. [Means for solving the problem]

[0006] A shovel according to one embodiment of the present invention includes a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, a cab mounted on the upper rotating body, a left operation lever disposed on the left side of a driver's seat in the cab, a right operation lever disposed on the right side of the driver's seat in the cab, an imaging device attached to the cab for capturing an image of at least an operator seated in the driver's seat, and a function for detecting a change in the upper body posture of the operator seated in the driver's seat by applying image processing to an image captured by the imaging device. Operated by the left operating lever or the right operating leverand a computing device that determines whether or not restrictions on the movement of the actuator are necessary, and an operator seated in the driver's seat holds the left operating lever with his left hand to operate the left operating lever, and holds the right operating lever with his right hand to operate the right operating lever. [Effects of the Invention]

[0007] An excavator according to an embodiment of the present invention allows the operator in the cab to be more accurately checked. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a work monitoring system. [Figure 2] 2 is a diagram showing an example of the configuration of a drive system mounted on the excavator of FIG. 1. [Figure 3] FIG. 2 is a diagram illustrating an example of the configuration of a control system mounted on the excavator of FIG. 1. [Figure 4] FIG. 2 is a side view of an operator sitting in a driver's seat provided in the cabin. [Figure 5] FIG. 2 is a top view of a driver's seat provided in the cabin. [Figure 6] FIG. 10 is a diagram illustrating a range in which the center of gravity position of the operator's upper body is distributed. [Figure 7] 10 is a flowchart of an estimation process. [Figure 8] FIG. 2 is a side view of an operator sitting in a driver's seat provided in the cabin. DETAILED DESCRIPTION OF THE INVENTION

[0009] First, with reference to Fig. 1, a work monitoring system SYS including a work machine according to an embodiment of the present invention will be described. Fig. 1 is a diagram showing an example of the configuration of the work monitoring system SYS. The work monitoring system SYS is a system that monitors the condition of an operator who operates a work machine. The operator's condition includes, for example, the operator's fatigue state. Work machines include excavators (shovels), lifting magnet machines, cranes, forklifts, etc.

[0010] In the example of Fig. 1, the work monitoring system SYS includes a shovel 100, a support device 200, and a management device 300. The work monitoring system SYS may each include one shovel 100, one support device 200, and one management device 300. In the example of Fig. 1, the work monitoring system SYS is made up of one shovel 100, one support device 200, and one management device 300.

[0011] The excavator 100 is mainly composed of a lower traveling body 1 and an upper rotating body 3. The upper rotating body 3 is mounted on the lower traveling body 1 via a rotating mechanism 2. A boom 4 is attached to the upper rotating body 3. An arm 5 is attached to the tip of the boom 4. A bucket 6 is attached to the tip of the arm 5 as an end attachment.

[0012] The boom 4, arm 5, and bucket 6 constitute an excavation attachment, which is an example of an attachment serving as a working mechanism. The boom 4 is driven by a boom cylinder 7. The arm 5 is driven by an arm cylinder 8. The bucket 6 is driven by a bucket cylinder 9.

[0013] A cabin 10 serving as a driver's cab is mounted on the upper rotating body 3. An engine 11 serving as a power source for the excavator is mounted on the upper rotating body 3 behind the cabin 10. The engine 11 is an internal combustion engine such as a diesel engine. A positioning device P1 and a communication device T1 are also attached to the upper rotating body 3.

[0014] A driver's seat 110 and a console 120 are installed in the cabin 10. Furthermore, a controller 30 and an information acquisition device C1 are installed in the cabin 10.

[0015] The controller 30 is a computing device that executes various calculations. In this embodiment, the controller 30 is a microcomputer that includes a CPU, a volatile storage device, and a nonvolatile storage device. The various functions of the controller 30 are realized, for example, by the CPU executing a program stored in the nonvolatile storage device.

[0016] The information acquisition device C1 is configured to acquire information about the posture of an operator operating the working mechanism and output the acquired information to the controller 30. In this embodiment, the information acquisition device C1 is an imaging device such as a camera attached to a pillar, side wall, or ceiling of the cabin 10, or other location away from the driver's seat 110, so as to capture an image of the operator sitting in the driver's seat 110. In this case, the operator may be wearing a body suit that can assist the imaging device in acquiring information about the operator's posture. The body suit is formed, for example, from a fabric on which a plurality of markers of a predetermined shape (e.g., circular) are arranged at equal intervals on its surface. The body suit is typically formed from a fabric that fits closely to the operator's body, but may also be formed from a fabric that does not fit closely to the body. The body suit may cover the entire body or the upper body. The imaging device acquires information about the operator's posture based on the positional relationship of the plurality of markers, for example. The information acquisition device C1 may be an optical ranging device such as a 3D scanner or LIDAR. The information acquisition device C1 may be a non-contact type device such as an imaging device or an optical distance measuring device, or a contact type device such as a body suit with a built-in elastic sensor worn by the operator, or a wearable sensor such as an acceleration sensor attached to the operator. Alternatively, the information acquisition device C1 may be a sensor attached to the driver's seat 110 to detect the tension of a seat belt.

[0017] The positioning device P1 is configured to measure the position and orientation of the upper rotating body 3. The positioning device P1 is, for example, a GNSS compass, and detects the position and orientation of the upper rotating body 3 and outputs the detected values ​​to the controller 30.

[0018] The communication device T1 is configured to control communication with an external device outside the shovel 100. In this embodiment, the communication device T1 controls communication with the external device via a satellite communication network, a mobile phone communication network, the Internet network, or the like. The communication device T1 may also control communication with the support device 200 via a short-range wireless communication network such as Wi-Fi (registered trademark), Bluetooth (registered trademark), or wireless LAN.

[0019] The support device 200 is a mobile terminal device, such as a tablet PC, a smartphone, a wearable PC, or smart glasses carried by a worker at a work site.

[0020] The management device 300 is a fixed terminal device such as a management server, and is, for example, a computer installed in a management center outside a work site. The management device 300 may also be, for example, a portable computer such as a notebook PC, a tablet PC, or a smartphone.

[0021] Fig. 2 shows an example of the configuration of the drive system of the excavator 100. In Fig. 2, the mechanical power transmission system is indicated by double lines, the hydraulic oil lines by thick solid lines, the pilot lines by thick dashed lines, and the electric drive and control system by dotted lines.

[0022] The drive system of the excavator 100 includes an engine 11 , a regulator 13 , a main pump 14 , a pilot pump 15 , a control valve 17 , an operating device 26 , an operating pressure sensor 29 , and a controller 30 .

[0023] The engine 11 is controlled by an engine control unit (hereinafter referred to as "ECU 74"). The output shaft of the engine 11 is connected to the input shafts of the main pump 14 and the pilot pump 15. The main pump 14 and the pilot pump 15 are driven by the power of the engine 11.

[0024] The main pump 14 supplies hydraulic oil to a control valve 17 via a hydraulic oil line 16. In this embodiment, the main pump 14 is a swash plate type variable displacement hydraulic pump.

[0025] The regulator 13 controls the discharge amount of the main pump 14. In this embodiment, the regulator 13 adjusts the tilt angle of the swash plate of the main pump 14 in response to a control signal from the controller 30 or the like.

[0026] The pilot pump 15 supplies hydraulic oil to various hydraulic control devices. In this embodiment, the pilot pump 15 is a fixed displacement hydraulic pump.

[0027] The control valve 17 is a hydraulic control device that controls the hydraulic system mounted on the excavator 100. In this embodiment, the control valve 17 includes flow control valves corresponding to the boom cylinder 7, arm cylinder 8, bucket cylinder 9, left-side traveling hydraulic motor 1L, right-side traveling hydraulic motor 1R, and swing hydraulic motor 2A (hereinafter collectively referred to as "hydraulic actuators"). The control valve 17 can selectively supply hydraulic oil discharged by the main pump 14 to one or more hydraulic actuators.

[0028] The operating device 26 is used to operate the hydraulic actuator. In this embodiment, the operating device 26 includes an operating lever 26A, travel pedals 26B, and a travel lever 26C. The operating lever 26L includes a left operating lever 26AL related to arm opening / closing operation and swing operation, and a right operating lever 26AR related to boom raising / lowering operation and bucket opening / closing operation. The travel pedals 26B include a left traveling pedal 26BL related to forward / reverse operation of the left crawler, and a right traveling pedal 26BR related to forward / reverse operation of the right crawler. The travel lever 26C includes a left traveling lever 26CL interlocked with the left traveling pedal 26BL, and a right traveling lever 26CR interlocked with the right traveling pedal 26BR.

[0029] The operating device 26 is connected to the control valve 17 via a hydraulic oil line 27. More specifically, the operating device 26 is connected to a pilot port of a flow control valve in the control valve 17.

[0030] The operating device 26 is connected to an operating pressure sensor 29 via a hydraulic oil line 28. The operating pressure sensor 29 detects the operation of the operating device 26 in the form of pressure and outputs the detected value to a controller 30. The controller 30 detects the operation of each operating device 26 (for example, whether a lever is operated, the direction of lever operation, the amount of lever operation, etc.) based on the output of the operating pressure sensor 29. However, the detection of the operation of the operating device 26 may be performed using a sensor other than a pressure sensor, such as an inclination sensor that detects the inclination of the operating lever 26A.

[0031] The controller 30 is configured to derive information about the state of the operator based on the information about the posture of the operator acquired by the information acquisition device C1. In this embodiment, the controller 30 includes an estimation unit 30a.

[0032] The estimation unit 30a estimates the state of the operator based on information about the operator's posture acquired by the information acquisition device C1. In this embodiment, the estimation unit 30a estimates the operator's fatigue state based on information about the operator's posture acquired by the information acquisition device C1. For example, the estimation unit 30a estimates the position of the center of gravity of the operator's upper body based on information about the posture of the operator's upper body acquired by the information acquisition device C1. Then, the estimation unit 30a estimates the operator's fatigue state based on the distribution of the position of the center of gravity of the operator's upper body over a predetermined time period. However, the estimation unit 30a may also estimate the position of the center of gravity of the operator's entire body based on information about the operator's posture acquired by the information acquisition device C1, and estimate the operator's fatigue state based on the distribution of the position of the center of gravity of the operator's entire body over a predetermined time period.

[0033] When a bodysuit is used as the information acquisition device C1, the estimation unit 30a receives the outputs of multiple stretch sensors embedded in the bodysuit via short-range wireless communication or the like, and derives information about the posture of the operator's whole body or upper body. Then, the estimation unit 30a estimates the center of gravity of the operator's whole body or upper body based on the information about the posture of the operator's whole body or upper body. The stretch sensors are configured to detect, for example, changes in the resistance value of the fibers that make up the bodysuit as the stretch of the fibers.

[0034] When a sensor for detecting the tension of a seat belt is employed as the information acquisition device C1, the estimation unit 30a may estimate the position of the center of gravity of the whole body or upper body of the operator based on, for example, the maximum value of the tension. Also, the estimation unit 30a may estimate the number of times the position of the center of gravity of the whole body or upper body of the operator moves based on the number of times the tension fluctuates.

[0035] The controller 30 may also be configured to control the external device C2 based on the derived information about the state of the operator. In this embodiment, the controller 30 includes a device control unit 30b.

[0036] The external device C2 includes at least one of a display device 130 (see FIG. 5), a sound output device, a fragrance emitting device, a regulator 13, a gate lock valve 50 (see FIG. 3), a pilot pressure control valve 51 (see FIG. 3), and a communication device T1.

[0037] The equipment control unit 30b controls the external equipment C2 based on the fatigue state of the operator estimated by the estimation unit 30a. For example, when the estimation unit 30a estimates that the fatigue state of the operator has reached a predetermined level, the equipment control unit 30b notifies the operator that the operator is fatigued. Specifically, the equipment control unit 30b outputs a control command to the audio output device, causing the audio output device to output information that the operator is fatigued. The audio output device may output audio to a worker working around the shovel 100, or may output audio to the operator in the cabin 10. Furthermore, the equipment control unit 30b may cause the display device 130 to display information that the operator is fatigued. Like the audio output device, the display device 130 may be configured to be visible to a worker working around the shovel 100.

[0038] Alternatively, when the estimation unit 30a estimates that the operator's fatigue state has reached a predetermined level, the equipment control unit 30b may transmit information indicating that the operator is fatigued to at least one of the support device 200 and the management device 300 via the communication device T1. In this case, the equipment control unit 30b may transmit at least one of information regarding the work content and information regarding the work environment in association with each other. This is to enable a manager or the like to analyze the relationship between the operator's fatigue and the work content or the work environment. The information regarding the work content includes, for example, the output of the operating pressure sensor 29. The information regarding the work environment includes, for example, at least one of information regarding the hardness of the excavation target (earth, sand, etc.) and information regarding the outside temperature. The information regarding the hardness of the excavation target (earth, sand, etc.) may be derived, for example, based on the pressure in the bottom-side oil chamber of the boom cylinder 7. This configuration allows a manager or the like to appropriately change the operator's future work content or work time. For example, a manager or the like can determine the time it takes for each operator to become fatigued and determine the work allocation for each operator.

[0039] Alternatively, when the estimation unit 30a estimates that the fatigue state of the operator has reached a predetermined level, the equipment control unit 30b may use an actuator (not shown) to change the inclination of the seat surface of the driver's seat 110 in the front-to-rear direction. This is to reduce the fatigue of the operator by changing the seated posture of the operator.

[0040] Alternatively, the device control unit 30b may emit a scent based on information about the operator's upper body posture acquired by the information acquisition device C1. For example, when the estimation unit 30a estimates that the operator's fatigue state has reached a predetermined level, the device control unit 30b may output a control command to the scent emission device to emit a scent. The scent may be a fragrance that relaxes the operator, or a fragrance that awakens the operator. Furthermore, the device control unit 30b may output music that relaxes the operator from the audio output device, or music that awakens the operator from the audio output device.

[0041] Alternatively, the equipment control unit 30b may limit the movement of the excavator 100 when the estimator 30a estimates that the operator's fatigue state has reached a predetermined level. This is to prompt the operator to stop work or take a break. For example, the equipment control unit 30b may output a control command to the regulator 13 to limit the discharge rate of the main pump 14, thereby slowing down the movement of the excavation attachment. Alternatively, the equipment control unit 30b may output a control command to the gate lock valve 50 to cut off the flow rate of hydraulic oil supplied to the operating device 26, i.e., to disable the operating device 26, thereby stopping the movement of the excavation attachment. Alternatively, the equipment control unit 30b may output a control command to the pilot pressure control valve 51 to adjust the pilot pressure generated by the operating device 26, thereby limiting the movement of the excavation attachment. Alternatively, if the operating lever 26A has a force feedback function, the equipment control unit 30b may increase the operation reaction force of the operating lever 26A when the estimator 30a estimates that the operator's fatigue state has reached a predetermined level. This is because making the operating lever 26A difficult to operate prompts the operator to stop the work.

[0042] Alternatively, the equipment control unit 30b may switch the operation mode of the shovel 100 to the assist mode when the estimating unit 30a estimates that the fatigue state of the operator has reached a predetermined level. The assist mode may be, for example, an operation mode that smooths out rough movement of the hydraulic actuator caused by fluctuations in the operation amount of the operating lever 26A. In this case, the equipment control unit 30b may output a control command to the pilot pressure control valve 51 to adjust the pilot pressure generated by the operating device 26, thereby suppressing fluctuations in the pilot pressure.

[0043] Alternatively, the equipment control unit 30b may limit the movement of the shovel 100 when a limiting command is received from the support device 200 or the management device 300 via the communication device T1. With this configuration, for example, when a manager at a management center receives information that the operator is tired, the manager can remotely limit the movement of the shovel 100 by transmitting a limiting command to the shovel 100.

[0044] Next, the control system of the shovel 100 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of a control system mounted on the shovel 100.

[0045] The controller 30 operates by receiving power from a storage battery 70. The storage battery 70 is charged by a generator 11a driven by the engine 11. The power of the storage battery 70 is also supplied to the information acquisition device C1, electrical components 72, a starter 11b of the engine 11, and the like. The starter 11b is driven by power from the storage battery 70 to start the engine 11.

[0046] The engine 11 is controlled by the ECU 74. The ECU 74 transmits various data indicating the state of the engine 11 to the controller 30. The controller 30 stores this data in a temporary storage unit (volatile storage device).

[0047] A water temperature sensor 11c provided in the engine 11 transmits data on the coolant temperature to the controller 30. The regulator 13 transmits information on the swash plate tilt angle to the controller 30. The discharge pressure sensor 14b transmits information on the discharge pressure of the main pump 14 to the controller 30.

[0048] An oil temperature sensor 14c is provided in a conduit CL between the main pump 14 and a tank storing hydraulic oil to be sucked into the main pump 14. The oil temperature sensor 14c transmits information relating to the temperature of the hydraulic oil flowing through the conduit CL to the controller 30.

[0049] The operating pressure sensor 29 transmits to the controller 30, for example, information relating to the pilot pressure acting on the control valve 17 when the operating lever 26A is operated.

[0050] The engine speed adjustment dial 75 is a dial for adjusting the speed of the engine 11. In this embodiment, the engine speed adjustment dial 75 is configured to be able to switch the engine speed in multiple stages of four or more, including SP mode, H mode, A mode, and idling mode. The engine speed adjustment dial 75 transmits information relating to the setting state of the speed of the engine 11 to the controller 30.

[0051] The SP mode is a rotation speed mode selected when priority is given to the amount of work, and the highest engine rotation speed is used. The H mode is a rotation speed mode selected when priority is given to both the amount of work and fuel economy, and the second highest engine rotation speed is used. The A mode is a rotation speed mode selected when priority is given to fuel economy while operating the excavator at low noise, and the third highest engine rotation speed is used. The idling mode is a rotation speed mode selected when the engine 11 is to be in an idling state, and the lowest engine rotation speed is used. The engine 11 is controlled so that its rotation speed becomes the same as the engine rotation speed set by the engine rotation speed adjustment dial 75.

[0052] The gate lock valve 50 is configured to be able to switch between a connected state and a disconnected state of a pilot line PL1 connecting the pilot pump 15 and the operating device 26. When the pilot line PL1 is in a connected state, the operating device 26 is in an enabled state, and when the pilot line PL1 is in a disconnected state, the operating device 26 is in an disabled state. The enabled state of the operating device 26 means a state in which an operation on the operating device 26 is reflected in the movement of the excavator 100, and the disabled state of the operating device 26 means a state in which an operation on the operating device 26 is not reflected in the movement of the excavator 100. In this embodiment, the gate lock valve 50 connects the pilot line PL1 when the gate lock lever GL is pulled up, and disconnects the pilot line PL1 when the gate lock lever GL is pushed down. The gate lock valve 50 may also be configured to be able to switch between a connected state and a disconnected state of the pilot line PL1 in response to a control command from the controller 30.

[0053] The information acquisition device C1 may be configured to acquire information about the upper body posture of the operator operating the working mechanism when the operating device 26 is in an enabled state. For example, the information acquisition device C1 may be configured to acquire information about the upper body posture of the operator operating the excavation attachment only when the operating lever 26A is in an enabled state. In this case, the information acquisition device C1 may be configured not to acquire information about the upper body posture of the operator when the operating lever 26A is in an disabled state. Alternatively, the information acquisition device C1 may be configured so that information about the upper body posture of the operator acquired when the operating lever 26A is in an disabled state is not used by the controller 30. Specifically, the information acquisition device C1 may delete information about the upper body posture of the operator acquired when the operating lever 26A is in an disabled state.

[0054] Furthermore, the information acquisition device C1 may be configured to acquire information about the posture of the operator's upper body while the operator is performing an operation, i.e., when the operation lever 26A is in an operated state. In this case, the information acquisition device C1 may be configured not to acquire information about the posture of the operator's upper body when the operator is not performing an operation, i.e., when the operation lever 26A is in a non-operated state. Alternatively, the information acquisition device C1 may be configured not to use information about the posture of the operator's upper body acquired when the operation lever 26A is in a non-operated state by the controller 30. Specifically, the information acquisition device C1 may erase information about the posture of the operator's upper body acquired when the operation lever 26A is in a non-operated state.

[0055] The pilot pressure control valve 51 is configured to adjust the pilot pressure, which is the pressure of hydraulic oil in a pilot line PL2 that connects the pilot port of the flow control valve in the control valve 17 and the operating device 26. In this embodiment, the pilot pressure control valve 51 is configured to adjust the pilot pressure in response to a control command from the controller 30. This configuration enables the controller 30 to limit the amount of displacement of the flow control valve relative to the amount of operation of the operating lever 26A. This makes it possible to limit the movement of the hydraulic actuator, and ultimately the movement of the excavation attachment.

[0056] Next, with reference to FIGS. 4 to 6, changes in the upper body posture of an operator sitting in the driver's seat 110 installed in the cabin 10 will be described. FIG. 4 is a side view of an operator sitting in the driver's seat 110 installed in the cabin 10, and includes FIGS. 4(A) and 4(B). FIG. 4(A) shows the state of the operator at the start of work, and FIG. 4(B) shows the state of the operator after working for a long period of time. FIG. 5 is a top view of the driver's seat 110 installed in the cabin 10, and shows the position of the center of gravity CG1 of the operator's upper body in FIG. 4(A) and the position of the center of gravity CG2 of the operator's upper body in FIG. 4(B). FIG. 6 is a diagram illustrating the range in which the position of the center of gravity CG of the operator's upper body is distributed, and includes FIGS. 6(A) and 6(B). FIG. 6(A) is a top view of the driver's seat 110, and FIG. 6(B) shows the frequency distribution of the X-coordinate of the position of the center of gravity CG.

[0057] The driver's seat 110 includes a seat 112 on which the operator sits and a backrest 114. In this embodiment, the driver's seat 110 is a reclining seat, and the tilt angle of the backrest 114 is adjustable. Armrests 116 (a left armrest 116L and a right armrest 116R) are arranged on both the left and right sides of the driver's seat 110. The armrests 116 are configured to be rotatable.

[0058] The console 120 includes a left console 120L and a right console 120R. The left console 120L is disposed on the left side of the driver's seat 110, and the right console 120R is disposed on the right side of the driver's seat 110. The driver's seat 110 and the console 120 are installed so as to be movable on rails fixed to the floor surface of the cabin 10. Therefore, the operator can move and fix the driver's seat 110 and the console 120 to a desired position relative to the windshield of the cabin 10. In addition, the driver's seat 110 alone can be slid forward and backward, and the position of the driver's seat 110 relative to the position of the console 120 can also be adjusted.

[0059] A left operation lever 26AL is provided in front of the left console 120L, and a right operation lever 26AR is provided in front of the right console 120R. An operator sitting in the driver's seat 110 grips the left operation lever 26AL with his left hand to operate the left operation lever 26AL, and grips the right operation lever 26AR with his right hand to operate the right operation lever 26AR.

[0060] A travel pedal 26B is disposed on the floor in front of the driver's seat 110. The operator sitting in the driver's seat 110 operates the left travel pedal 26BL with his left foot to drive the left-side travel hydraulic motor 1L, and operates the right travel pedal 26BR with his right foot to drive the right-side travel hydraulic motor 1R.

[0061] A left travel lever 26CL is provided near the left travel pedal 26BL. An operator sitting in the driver's seat 110 can operate the left travel lever 26CL with their left hand to drive the left-side travel hydraulic motor 1L in the same way as operating the left travel pedal 26BL with their left foot. Also, a right travel lever 26CR is provided near the right travel pedal 26BR. An operator sitting in the driver's seat 110 can operate the right travel lever 26CR with their right hand to drive the right-side travel hydraulic motor 1R in the same way as operating the right travel pedal 26BR with their right foot.

[0062] A display device 130 that displays information such as the working conditions and operating state of the shovel 100 is disposed at the front right of the cabin 10. The operator sitting in the driver's seat 110 can perform work using the shovel 100 while checking the information displayed on the display device 130.

[0063] A gate lock lever GL is provided on the left side of the driver's seat 110 (i.e., the side where the door for getting in and out of the cabin 10 is located). Figures 4(A), 4(B), and 5 show the state when the gate lock lever GL is pulled up. By pulling up the gate lock lever GL, the operator is permitted to start the engine 11, allowing the operator to operate the shovel 100. On the other hand, the operator can disable the start of the engine 11 by pushing down the gate lock lever GL. Therefore, the operator cannot operate the shovel 100 unless he or she is sitting in the driver's seat 110 and pulls up the gate lock lever GL. With this configuration, the shovel 100 can prevent the excavation attachment from moving even if part of the operator's body accidentally comes into contact with the operating lever 26A, as long as the gate lock lever GL is pushed down.

[0064] As shown in Figures 4 to 6, the center of gravity position CG of the operator's upper body often differs between when the operator is not tired and when the operator is tired. In the examples of Figures 4 to 6, the center of gravity position CG1 of the operator's upper body at a first point in time when the operator is not tired is located forward (toward the +X side) of the center of gravity position CG2 of the operator's upper body at a second point in time when the operator is tired. Note that the X axis parallel to the fore-aft axis of the shovel 100 has its origin O at the rear end of the seating surface of the seat 112.

[0065] More specifically, as shown in FIG. 6(A), the center of gravity position CG1 when the operator is not tired is located within a distribution range ER1, and the center of gravity position CG2 when the operator is tired is located within a distribution range ER2. In the example of FIG. 6(A), the distribution range ER1 indicates the distribution range of the center of gravity position CG1 estimated every minute for a period of three hours from the start of work in the morning. The distribution range ER2 indicates the distribution range of the center of gravity position CG2 estimated every minute for a period of three hours from the start of work in the afternoon, when the operator is thought to be more tired than in the morning. The dashed lines in FIG. 6(A) represent the positions of the buttocks and thighs of the operator sitting in the driver's seat 110.

[0066] The solid line in FIG. 6(B) shows the frequency distribution of the X-coordinates of 180 center-of-gravity positions CG1 estimated over a three-hour period in the morning, and the dashed line shows the frequency distribution of the X-coordinates of 180 center-of-gravity positions CG2 estimated over a three-hour period in the afternoon. The range of variation W1 in the X-axis direction of the center-of-gravity position CG1 when the operator is not tired is smaller than the range of variation W2 in the X-axis direction of the center-of-gravity position CG2 when the operator is tired, as shown in FIG. 6(B), for example. Furthermore, the maximum frequency F1 of the center-of-gravity position CG1 when the operator is not tired is larger than the maximum frequency F2 of the center-of-gravity position CG2 when the operator is tired, as shown in FIG. 6(B), for example. However, the characteristics shown in FIG. 6(B) vary depending on the operator. Furthermore, while the above description mainly relates to the characteristics related to the transition of the center-of-gravity position CG in the X-axis direction, the same applies to the characteristics related to the transition of the center-of-gravity position CG in the Y-axis direction and the characteristics related to the transition of the center-of-gravity position CG in the Z-axis direction.

[0067] Therefore, the controller 30 is configured to estimate the fatigue state of the operator by utilizing such characteristics.

[0068] 7 is a flowchart of an example of a process (hereinafter referred to as "estimation process") in which the controller 30 estimates the fatigue state of the operator. The controller 30 repeatedly executes this estimation process at predetermined control intervals (for example, every minute).

[0069] First, the controller 30 estimates the center of gravity CG of the operator's upper body (step ST1). In this embodiment, the estimation unit 30a of the controller 30 estimates the center of gravity CG of the operator's upper body by applying image processing to an image of the operator acquired by a camera serving as the information acquisition device C1. The center of gravity CG is, for example, a three-dimensional coordinate in a reference coordinate system. The reference coordinate system is, for example, an orthogonal coordinate system with the center of the camera as the origin.

[0070] The estimation unit 30a may omit estimating the center of gravity position CG of the operator's upper body when predetermined conditions are met. The predetermined conditions include, for example, "being in the middle of a swing operation." This is because, during a swing operation, the operator's upper body posture is easily changed due to the influence of angular acceleration around the swing axis. In other words, this is because it is not possible to distinguish between a change in upper body posture during a swing operation and a change in upper body posture due to fatigue. In this case, the estimation unit 30a may determine whether or not a swing operation is in progress based on, for example, the output of the operating pressure sensor 29. For the same reason, the predetermined conditions may include at least one of "being in the middle of excavation" and "being in the middle of traveling," etc.

[0071] Thereafter, the controller 30 estimates the fatigue state based on the transition of the center-of-gravity position CG (step ST2). In this embodiment, the estimation unit 30a of the controller 30 estimates the fatigue state based on the transition of a plurality of past center-of-gravity positions CG, including the currently estimated center-of-gravity position CG.

[0072] Specifically, the estimation unit 30a derives the number (frequency) of center-of-gravity positions CG that belong to the distribution range ER2 during a recent predetermined time period (e.g., the most recent 30 minutes), and estimates the operator's fatigue state based on the frequency. For example, under the assumption that the higher the frequency, the greater the fatigue, the estimation unit 30a determines to which of multiple preset levels the current fatigue state belongs. The frequency of center-of-gravity positions CG that belong to a specific distribution range may be reset when a predetermined reset condition is met. The predetermined reset condition may include, for example, at least one of "the seat belt being unfastened," "the engine 11 being turned off," and "the gate lock lever GL being pressed down."

[0073] The estimation unit 30a may also estimate the operator's fatigue state based on the movement distance of the center of gravity position CG in a predetermined time, the frequency of each movement distance, or the time interval at which movement occurs.

[0074] The distribution range ER2 is a three-dimensional range pre-stored in a non-volatile storage device. In this embodiment, it is stored in a manner that allows it to be updated for each operator. The controller 30 identifies the operator, for example, by having the operator input a personal ID or password when starting the excavator 100. The controller 30 may also identify the operator by performing short-range wireless communication with a mobile information terminal such as a mobile phone or smartphone carried by the operator sitting in the driver's seat. With this configuration, the controller 30 can respond appropriately even when the operator is changed.

[0075] Thereafter, the controller 30 determines whether or not the estimated fatigue state has reached a predetermined level (step ST3). In this embodiment, the estimation unit 30a determines whether or not the current level of the fatigue state has reached a predetermined level.

[0076] Next, another configuration example of the information acquisition device C1 will be described with reference to Fig. 8. Fig. 8 is a side view of an operator sitting in a driver's seat 110 installed in the cabin 10, and corresponds to Fig. 4(A). The example of Fig. 8 differs from the example of Fig. 4 in that a plurality of acceleration sensors AS attached to the operator are additionally employed as the information acquisition device C1.

[0077] In the example of Figure 8, the acceleration sensors AS include a head acceleration sensor AS1, a shoulder acceleration sensor AS2, a chest acceleration sensor AS3, an upper arm acceleration sensor AS4, a forearm acceleration sensor AS5, an abdominal acceleration sensor AS6, a thigh acceleration sensor AS7, and a leg acceleration sensor AS8. The upper arm acceleration sensor AS4 includes a left upper arm acceleration sensor AS4L and a right upper arm acceleration sensor AS4R. The forearm acceleration sensor AS5 includes a left forearm acceleration sensor AS5L and a right forearm acceleration sensor AS5R. The thigh acceleration sensor AS7 includes a left thigh acceleration sensor AS7L and a right thigh acceleration sensor AS7R. The leg acceleration sensor AS8 includes a left leg acceleration sensor AS8L and a right leg acceleration sensor AS8R. Note that Figure 8 does not show the right upper arm acceleration sensor AS4R, the right forearm acceleration sensor AS5R, the right thigh acceleration sensor AS7R, and the right leg acceleration sensor AS8R. In the example of Figure 8, a head acceleration sensor AS1 is attached to the helmet, and a shoulder acceleration sensor AS2, a chest acceleration sensor AS3, an upper arm acceleration sensor AS4, a forearm acceleration sensor AS5, an abdominal acceleration sensor AS6, a thigh acceleration sensor AS7, and a leg acceleration sensor AS8 are attached to the work clothes.

[0078] The controller 30 derives information about the posture of the operator's whole body or upper body based on the output of the acceleration sensor AS. Then, the controller 30 estimates the center of gravity CG of the operator's whole body or upper body based on the information about the posture of the operator's whole body or upper body. Then, the controller 30 estimates the operator's fatigue state based on the change in the center of gravity CG of the operator's whole body or upper body.

[0079] As described above, the shovel 100 as a work machine according to an embodiment of the present invention includes an excavation attachment as a working mechanism, an operating lever 26A for operating the excavation attachment, an information acquisition device C1 that acquires information about the upper body posture of an operator operating the excavation attachment when the operating lever 26A is in an active state, and a controller 30 as a computing device that derives information about the operator's condition based on the information about the operator's upper body posture acquired by the information acquisition device C1. This configuration enables the shovel 100 to more accurately estimate the operator's fatigue state, because the deterioration of the operator's upper body posture as fatigue progresses can be used to estimate the operator's fatigue state.

[0080] The work machine may be a lifting magnet machine, a crane, a forklift, or the like. In this case, the work mechanism includes a suction mechanism in a lifting magnet machine, a wire winding mechanism in a crane, or a lifting mechanism in a forklift, or the like.

[0081] The controller 30 preferably estimates the center of gravity (CG) of the operator's upper body from information about the posture of the operator's upper body acquired by the information acquisition device C1. The controller 30 then estimates the operator's fatigue state based on the change in the center of gravity (CG) of the operator's upper body. This configuration allows the controller 30 to more accurately estimate the operator's fatigue state. This is because the change in the center of gravity of the operator's upper body can be recognized as a change in the operator's upper body posture that accompanies the progression of fatigue, and the change in the center of gravity of the operator's upper body can be used to estimate the operator's fatigue state.

[0082] Preferably, the controller 30 estimates the operator's fatigue state based on information about the operator's upper body posture acquired by the information acquisition device C1, and notifies the operator that the operator is fatigued when it estimates that the operator's fatigue state has reached a predetermined level. With this configuration, the controller 30 can reliably notify a manager or the like that the operator is fatigued. Furthermore, the controller 30 can inform the operator of the objective determination result that the operator is fatigued even if the operator is not aware that he or she is fatigued.

[0083] The information acquisition device C1 may be an imaging device or an optical distance measuring device, may be a wearable sensor, or may be a sensor that detects the tension of a seat belt attached to the driver's seat 110. With this configuration, there is no adverse effect on seating comfort, unlike a detector embedded in the seat surface of the driver's seat 110. Furthermore, since the information acquisition device C1 does not require the driver's seat 110 to be replaced, it can be easily attached to a work machine that has already been shipped.

[0084] The controller 30 may emit a scent based on information about the operator's upper body posture acquired by the information acquisition device C1. With this configuration, the controller 30 can, for example, relieve the operator's fatigue. Alternatively, the controller 30 can restore the operator's ability to concentrate when the operator is distracted due to fatigue.

[0085] The controller 30 may limit the movement of the excavation attachment serving as a working mechanism based on information about the operator's upper body posture acquired by the information acquisition device C1. With this configuration, the controller 30 can prompt the operator to stop or suspend work or to take a break.

[0086] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments. Various modifications, substitutions, etc. may be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, features described separately may be combined unless technical contradictions arise. [Explanation of symbols]

[0087] 1···Undercarriage 1L···Left-side travel hydraulic motor 1R···Right-side travel hydraulic motor 2···Slewing mechanism 2A···Slewing hydraulic motor 3···Upper rotating body 4···Boom 5···Arm 6···Bucket 7···Boom cylinder 8···Arm cylinder 9···Bucket cylinder 10···Cabin 11···Engine 11a···Generator 11b···Starter 11c···Water temperature sensor 13···Regulator 14···Main pump 14b···Discharge pressure sensor 14c···Oil temperature sensor 15···Pilot pump 16···Hydraulic oil line 17···Control valve 26···Operating device 26A···Operating lever 26B···Travel pedal 26C···Travel lever 27, 28···Hydraulic oil lines 29... Operating pressure sensor 30... Controller 30a... Estimation unit 30b... Equipment control unit 50... Gate lock valve 51... Pilot pressure control valve 70... Storage battery 72... Electrical equipment 74... ECU 75... Engine speed adjustment dial 100... Excavator 110... Driver's seat 112... Seat 114... Backrest 116... Armrest 120... Console 130... Display device 200... Support device 300... Management device AS... Acceleration sensor C1... Information acquisition device C2... External device GL... Gate lock lever P1... Positioning device PL1, PL2... Pilot line T1... Communication device

Claims

1. a lower running body; an upper rotating body rotatably mounted on the lower traveling body; an operator's cab mounted on the upper rotating body; a left operation lever disposed on the left side of the driver's seat in the driver's cab; a right operation lever disposed on the right side of the driver's seat in the driver's cab; an imaging device attached to the driver's cab and configured to capture an image of at least an operator seated in the driver's seat; a computing device that determines whether or not it is necessary to restrict the movement of an actuator operated by the left operating lever or the right operating lever, based on a change in the upper body posture of an operator seated in the driver's seat ascertained by applying image processing to the image captured by the imaging device, an operator seated in the driver's seat holds the left operation lever with his left hand to operate the left operation lever, and holds the right operation lever with his right hand to operate the right operation lever; Shovel.

2. The imaging device is a camera. The shovel according to claim 1.

3. The imaging device is provided on a pillar of the driver's cab. The shovel according to claim 1.

4. the computing device determines whether or not restriction on movement of the actuator is necessary based on a change in the upper body posture of the operator seated in the driver's seat ascertained by applying image processing to the image when the operation devices including the left operation lever and the right operation lever are in an active state. The shovel according to claim 1.

5. the computing device acquires the image when an operating device including the left operating lever and the right operating lever is in an operating state. The shovel according to claim 1.

6. the computing device acquires the image when an operating device including the left operating lever and the right operating lever is in an operating state, and determines whether or not a restriction on movement of the actuator is necessary based on a change in the upper body posture of an operator seated in the driver's seat ascertained by applying image processing to the image when the operating device is in the operating state. The shovel according to claim 1.

7. the computing device stops the movement of the actuator based on a change in the upper body posture of the operator seated in the driver's seat, which change is grasped by applying image processing to the image. The shovel according to claim 1.

8. an imaging device that captures an image of at least an operator sitting in the driver's seat of the shovel; a computing device that determines whether or not it is necessary to restrict the movement of an actuator operated by a left operating lever or a right operating lever, based on a change in the upper body posture of an operator seated in the driver's seat ascertained by applying image processing to the image captured by the imaging device, The shovel includes a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, a driver's cab mounted on the upper rotating body, the left operation lever disposed on the left side of the driver's seat in the driver's cab, and the right operation lever disposed on the right side of the driver's seat in the driver's cab, an operator seated in the driver's seat holds the left operation lever with his left hand to operate the left operation lever, and holds the right operation lever with his right hand to operate the right operation lever; Work monitoring system.

Images