US20170121930A1 - Construction machine control system, construction machine, and method of controlling construction machine - Google Patents

Construction machine control system, construction machine, and method of controlling construction machine Download PDF

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Publication number
US20170121930A1
US20170121930A1 US14/391,567 US201414391567A US2017121930A1 US 20170121930 A1 US20170121930 A1 US 20170121930A1 US 201414391567 A US201414391567 A US 201414391567A US 2017121930 A1 US2017121930 A1 US 2017121930A1
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United States
Prior art keywords
amount
arm
bucket
boom
limited amount
Prior art date
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Abandoned
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US14/391,567
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English (en)
Inventor
Jin Kitajima
Yoshiki Kami
Takeo Yamada
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Komatsu Ltd
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Komatsu Ltd
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Filing date
Publication date
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Assigned to KOMATSU LTD. reassignment KOMATSU LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KAMI, Yoshiki, KITAJIMA, JIN, YAMADA, TAKEO
Publication of US20170121930A1 publication Critical patent/US20170121930A1/en
Abandoned legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
    • E02F3/435—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/30—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom
    • E02F3/32—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom working downwardly and towards the machine, e.g. with backhoes
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
    • E02F9/2228—Control of flow rate; Load sensing arrangements using pressure-compensating valves including an electronic controller
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2285—Pilot-operated systems
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2296—Systems with a variable displacement pump
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/26—Indicating devices
    • E02F9/261—Surveying the work-site to be treated
    • E02F9/262—Surveying the work-site to be treated with follow-up actions to control the work tool, e.g. controller
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/26—Indicating devices
    • E02F9/264—Sensors and their calibration for indicating the position of the work tool
    • E02F9/265—Sensors and their calibration for indicating the position of the work tool with follow-up actions (e.g. control signals sent to actuate the work tool)

Definitions

  • the present invention relates to a construction machine control system, a construction machine, and a method of controlling construction machine.
  • a construction machine like an excavator includes a work machine that includes a boom, an arm, and a bucket.
  • Patent Literatures 1 and 2 disclose limited excavation control in which a bucket is moved based on a target excavation landform indicating a target shape of an excavation object.
  • Patent Literature 1 Japanese Patent Application Laid-open No. 2013-217138
  • Patent Literature 2 Japanese Patent Application Laid-open No. 2006-265954
  • a construction machine includes an operating device that an operator operates to drive a work machine.
  • the limited excavation control if a boom is not moved at a high speed but is slower than an arm and a bucket, the bucket may not be moved based on a target excavation landform and excavation accuracy may decrease.
  • An object of some aspects of the present invention is to provide a construction machine control system, a construction machine, and a method of controlling the construction machine capable of suppressing a decrease in excavation accuracy.
  • a first aspect of the present invention provides a construction machine control system that includes a work machine including a boom, an arm, and a bucket, the system comprising: a boom limiting unit that determines a speed limit according to a distance between the bucket and a target excavation landform indicating a target shape of an excavation object based on the target excavation landform and bucket position data indicating the position of the bucket and limits the speed of the boom so that a speed at which the work machine approaches the target excavation landform is equal to or smaller than the speed limit; an operating device that is operated in order to drive a movable member including at least one of the arm and the bucket; a detection device that detects an amount of operation of the operating device; and a movable member control unit that outputs a control signal so that the movable member is driven with a limited amount of operation for limiting a speed of the movable member based on a detection result of the detection device.
  • the construction machine control system further comprises: a timer that starts time measurement based on the detection result of the detection device; and a limit value setting unit that sets the limited amount of operation for limiting the speed of the movable member in association with time elapsed from a start time of the time measurement of the timer, wherein the movable member control unit outputs a control signal so that the movable member is driven with the limited amount of operation in a predetermined period from the start time of the time measurement of the timer.
  • the start time of the time measurement of the timer includes at least one of a start time of an operation of the operating device, time at which a detection value of the detection device exceeds a threshold value, and time at which an amount of increase per unit time of the detection value of the detection device exceeds an allowable value.
  • the driving based on the limited amount of operation is disabled when the predetermined period has elapsed from the start time of the time measurement.
  • the limited amount of operation in a first half of the predetermined period is smaller than the limited amount of operation in a second half.
  • the construction machine control system further comprises: a hydraulic system that includes a first hydraulic actuator for driving the boom and a second hydraulic actuator for driving the movable member, wherein in an excavation operation of the bucket, the hydraulic system is operated so that the boom is raised and the arm is lowered, and the hydraulic system is driven with the limited amount of operation when the arm is lowered.
  • the hydraulic system includes a control valve that adjusts an amount of operating oil supplied to the second hydraulic actuator, and the control signal is output to the control valve.
  • the hydraulic system includes: a hydraulic pump that supplies operating oil; and a pump control unit that controls the hydraulic pump so that the operating oil is supplied with a first largest discharge capacity from the hydraulic pump in a first operation mode and the operating oil is supplied with a second largest discharge capacity smaller than the first largest discharge capacity from the hydraulic pump in a second operation mode, and the limited amount of operation in the second operation mode is smaller than the limited amount of operation in the first operation mode.
  • the movable member is replaceable, and the limited amount of operation when the movable member of a first weight is connected to the boom is smaller than the limited amount of operation when the movable member of a second weight smaller than the first weight is connected.
  • the output of the control signal is started so that the movable member is driven with the limited amount of operation when an amount of increase per unit time of the detection value of the detection device exceeds an allowable value, and the amount of increase includes a difference between the amount of operation of the operating device and a processing amount generated by low-pass filtering of the amount of operation.
  • the limited amount of operation is maintained to a certain value from a decrease start time.
  • the movable member is driven based on the amount of operation when the amount of operation is smaller than the limited amount of operation.
  • the construction machine includes a vehicle body that supports the boom, and the limited amount of operation when the work machine is driven so that a distance between the bucket and a reference position of the vehicle body is a first distance is smaller than the limited amount of operation when the work machine is driven so that the distance between the bucket and the reference position is a second distance shorter than the first distance.
  • a second aspect of the present invention provides a construction machine comprising: a lower traveling structure; an upper revolving structure that is supported by the lower traveling structure; a work machine that includes a boom, an arm and a bucket and is supported by the upper revolving structure; and the control system of the first aspect of the present invention.
  • a third aspect of the present invention provides a method of controlling a construction machine that includes a work machine including a boom, an arm, and a bucket, the method comprising: determining a speed limit according to a distance between the bucket and a target excavation landform indicating a target shape of an excavation object based on the target excavation landform and bucket position data indicating a position of the bucket and limiting a speed of the boom so that a speed at which the work machine approaches the target excavation landform is equal to or smaller than the speed limit; operating an operating device in order to drive a movable member including at least one of the arm and the bucket; detecting an amount of operation of the operating device; setting a limited amount of operation for limiting a speed of the movable member based on a detection result of the detection device; and outputting a control signal so that the movable member is driven with the limited amount of operation.
  • FIG. 1 is a perspective view illustrating an example of a construction machine.
  • FIG. 2 is a side view schematically illustrating an example of the construction machine.
  • FIG. 3 is a rear view schematically illustrating an example of the construction machine.
  • FIG. 4A is a block diagram illustrating an example of a control system.
  • FIG. 4B is a block diagram illustrating an example of a control system.
  • FIG. 5 is a schematic view illustrating an example of target construction information.
  • FIG. 6 is a flowchart illustrating an example of limited excavation control.
  • FIG. 7 is a diagram for describing an example of limited excavation control.
  • FIG. 8 is a diagram for describing an example of limited excavation control.
  • FIG. 9 is a diagram for describing an example of limited excavation control.
  • FIG. 10 is a diagram for describing an example of limited excavation control.
  • FIG. 11 is a diagram for describing an example of limited excavation control.
  • FIG. 12 is a diagram for describing an example of limited excavation control.
  • FIG. 13 is a diagram for describing an example of limited excavation control.
  • FIG. 14 is a diagram for describing an example of limited excavation control.
  • FIG. 15 is a diagram illustrating an example of a hydraulic cylinder.
  • FIG. 16 is a diagram illustrating an example of a cylinder stroke sensor.
  • FIG. 17 is a diagram illustrating an example of a control system.
  • FIG. 18 is a diagram illustrating an example of a control system.
  • FIG. 19 is a schematic diagram illustrating an example of an operation of a construction machine.
  • FIG. 20 is a functional block diagram illustrating an example of a control system.
  • FIG. 21 is a flowchart illustrating an example of a method of controlling the construction machine.
  • FIG. 22 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 23 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 24 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 25 is a functional block diagram illustrating an example of a control system.
  • FIG. 26 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 27 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 28 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 29 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 30 is a functional block diagram illustrating an example of a control system.
  • FIG. 31 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 32 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 33 is a flowchart illustrating an example of a method of controlling the construction machine.
  • FIG. 34 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 35 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 36 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 37 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 38 is a functional block diagram illustrating an example of a control system.
  • FIG. 39 is a flowchart illustrating an example of a method of controlling the construction machine.
  • FIG. 40 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 41 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 42 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 43 is a functional block diagram illustrating an example of a control system.
  • FIG. 44 is a schematic diagram illustrating an example of an operation of the construction machine.
  • FIG. 45 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 46 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 47 is a diagram for describing an example of a method of controlling the construction machine.
  • FIG. 1 is a perspective view illustrating an example of a construction machine 100 according to the present embodiment.
  • the construction machine 100 is an excavator 100 that includes a work machine 2 operating with hydraulic pressure.
  • the excavator 100 includes a vehicle body 1 and the work machine 2 .
  • a control system 200 that executes excavation control is mounted on the excavator 100 .
  • the vehicle body 1 includes a revolving structure 3 , a cab 4 , and a traveling device 5 .
  • the revolving structure 3 is disposed on the traveling device 5 .
  • the traveling device 5 supports the revolving structure 3 .
  • the revolving structure 3 may be referred to as an upper revolving structure 3 .
  • the traveling device 5 may be referred to as a lower traveling structure 5 .
  • the revolving structure 3 can revolve about a revolution axis AX.
  • a driver's seat 4 S on which an operator sits is provided in the cab 4 .
  • the operator operates the excavator 100 in the cab 4 .
  • the traveling device 5 includes a pair of crawler belts 5 Cr. With rotation of the crawler belts 5 Cr, the excavator 100 travels.
  • the traveling device 5 may include wheels (tires).
  • a positional relation of respective portions is described based on the driver's seat 4 S.
  • a front-rear direction is defined based on the driver's seat 4 S.
  • a left-right direction is defined based on the driver's seat 4 S.
  • a direction in which the driver's seat 4 S faces the front is defined as a front direction and a direction opposite to the front direction is defined as a rear direction.
  • the right and left sides in a lateral direction when the driver's seat 4 S faces the front are defined as right and left directions, respectively.
  • the revolving structure 3 includes an engine room 9 in which an engine is stored and a counterweight provided at the rear portion of the revolving structure 3 .
  • a handrail 19 is provided in a portion of the revolving structure 3 on the front side of the engine room 9 .
  • An engine, a hydraulic pump, and the like are disposed in the engine room 9 .
  • the work machine 2 is supported by the revolving structure 3 .
  • the work machine 2 includes a boom 6 connected to the revolving structure 3 , an arm 7 connected to the boom 6 , a bucket 8 connected to the arm 7 , a boom cylinder 10 driving the boom 6 , an arm cylinder 11 driving the arm 7 , and a bucket cylinder 12 driving the bucket 8 .
  • the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 are hydraulic cylinders driven by operating oil.
  • a base end of the boom 6 is connected to the revolving structure 3 with a boom pin 13 interposed.
  • a base end of the arm 7 is connected to a distal end of the boom 6 with an arm pin 14 interposed.
  • the bucket 8 is connected to a distal end of the arm 7 with a bucket pin 15 interposed.
  • the boom 6 can rotate about the boom pin 13 .
  • the arm 7 can rotate about the arm pin 14 .
  • the bucket 8 can rotate about the bucket pin 15 .
  • the arm 7 and the bucket 8 are movable members that can move on the distal end side of the boom 6 .
  • FIG. 2 is a side view schematically illustrating the excavator 100 according to the present embodiment.
  • FIG. 3 is a rear view schematically illustrating the excavator 100 according to the present embodiment.
  • the length L 1 of the boom 6 is the distance between the boom pin 13 and the arm pin 14 .
  • the length L 2 of the arm 7 is the distance between the arm pin 14 and the bucket pin 15 .
  • the length L 3 of the bucket 8 is the distance between the bucket pin 15 and a distal end 8 a of the bucket 8 .
  • the bucket 8 has a plurality of teeth.
  • the distal ends 8 a of the bucket 8 will be appropriately referred to as cutting edges 8 a.
  • the bucket 8 may not have teeth.
  • the distal end of the bucket 8 may be formed of a straight steel plate.
  • the excavator 100 includes a first cylinder stroke sensor 16 disposed in the boom cylinder 10 , a second cylinder stroke sensor 17 disposed in the arm cylinder 11 , and a third cylinder stroke sensor 18 disposed in the bucket cylinder 12 .
  • a stroke length of the boom cylinder 10 is obtained based on a detection result of the first cylinder stroke sensor 16 .
  • a stroke length of the arm cylinder 11 is obtained based on a detection result of the second cylinder stroke sensor 17 .
  • a stroke length of the bucket cylinder 12 is obtained based on a detection result of the third cylinder stroke sensor 18 .
  • the stroke length of the boom cylinder 10 will be appropriately referred to as a boom cylinder length
  • the stroke length of the arm cylinder 11 will be appropriately referred to as an arm cylinder length
  • the stroke length of the bucket cylinder 12 will be appropriately referred to as a bucket cylinder length.
  • the boom cylinder length, the arm cylinder length, and the bucket cylinder length will be appropriately collectively referred to as cylinder length data L.
  • the excavator 100 includes a position detection device 20 that can detect the position of the excavator 100 .
  • the position detection device 20 includes an antenna 21 , a global coordinate calculating unit 23 , and an inertial measurement unit (IMU) 24 .
  • IMU inertial measurement unit
  • the antenna 21 is a global navigation satellite systems (GNSS) antenna.
  • the antenna 21 is a real time kinematic-global navigation satellite systems (RTK-GNSS) antenna.
  • the antenna 21 is provided in the revolving structure 3 .
  • the antenna 21 is provided in the handrail 19 of the revolving structure 3 .
  • the antenna 21 may be provided in a rear direction of the engine room 9 .
  • the antenna 21 may be provided in the counterweight of the revolving structure 3 .
  • the antenna 21 outputs a signal corresponding to a received radio wave (GNSS radio wave) to the global coordinate calculating unit 23 .
  • GNSS radio wave received radio wave
  • the global coordinate calculating unit 23 detects an installed position P 1 of the antenna 21 in a global coordinate system.
  • the global coordinate system is a 3-dimensional coordinate system based on a reference position Pr set in a work area.
  • the reference position Pr is the position of a distal end of a reference post set in a work area.
  • the global coordinate system is a coordinate system based on the origin Pr (see FIG. 2 ) fixed on the earth.
  • a local coordinate system is a coordinate system based on the origin P 2 (see FIG. 2 ) fixed to the vehicle body 1 of the construction machine 100 .
  • the local coordinate system may be referred to as a vehicle body coordinate system.
  • the global coordinate system is represented by an XgYgZg orthogonal coordinate system.
  • a reference position (origin) Pr of the global coordinate system is positioned in a work area.
  • a direction within a horizontal plane is defined as an Xg-axis direction
  • a direction orthogonal to the Xg-axis direction within the horizontal plane is defined as a Yg-axis direction
  • a direction orthogonal to the Xg-axis direction and the Yg-axis direction is defined as a Zg-axis direction.
  • rotational (tilt) directions about the Xg, Yg, and Zg-axes are defined as ⁇ Xg, ⁇ Yg, and ⁇ Zg-directions, respectively.
  • the Xg-axis is orthogonal to a YgZg plane.
  • the Yg-axis is orthogonal to an XgZg plane.
  • the Zg-axis is orthogonal to an XgYg plane.
  • the XgYg plane is parallel to the horizontal plane.
  • the Zg-axis direction is a vertical direction.
  • the local coordinate system is represented by an XYZ orthogonal coordinate system.
  • the reference position (origin) P 2 of the local coordinate system is positioned at the revolution center AX of the revolving structure 3 .
  • a direction within a certain plane is defined as an X-axis direction
  • a direction orthogonal to the X-axis direction within the plane is defined as a Y-axis direction
  • a direction orthogonal to the X-axis direction and the Y-axis direction is defined as a Z-axis direction.
  • rotational (tilt) directions about the X, Y, and Z-axes are defined as ⁇ X, ⁇ Y, and ⁇ Z-directions, respectively.
  • the X-axis is orthogonal to the YZ plane.
  • the Y-axis is orthogonal to the XZ plane.
  • the Z-axis is orthogonal to the XY plane.
  • the antenna 21 includes a first antenna 21 A and a second antenna 21 B provided in the revolving structure 3 so as to be separated in a vehicle width direction.
  • the first antenna 21 A and the second antenna 21 B detect installed positions P 1 a and P 1 b, respectively, and output the same to the global coordinate calculating unit 23 .
  • the global coordinate calculating unit 23 acquires reference position data P represented by a global coordinate.
  • the reference position data P is data indicating the reference position P 2 positioned at the revolution axis (revolution center) AX of the revolving structure 3 .
  • the reference position data P may be data indicating the installed position P 1 .
  • the global coordinate calculating unit 23 generates revolving structure direction data Q based on two installed positions P 1 a and P 1 b.
  • the revolving structure direction data Q is determined based on an angle between a reference direction (for example, the north) of the global coordinate and a line determined by the installed positions P 1 a and P 1 b.
  • the revolving structure direction data Q indicates a direction in which the revolving structure 3 (the work machine 2 ) faces.
  • the global coordinate calculating unit 23 outputs the reference position data P and the revolving structure direction data Q to a display controller 28 (described later).
  • the IMU 24 is provided in the revolving structure 3 .
  • the IMU 24 is disposed under the cab 4 .
  • a high-rigidity frame is disposed in a portion of the revolving structure 3 under the cab 4 .
  • the IMU 24 is disposed on the frame.
  • the IMU 24 may be disposed on a lateral side (right or left side) of the revolution axis AX (the reference position P 2 ) of the revolving structure 3 .
  • the IMU 24 detects a tilt angle ⁇ 4 in the left-to-right direction of the vehicle body 1 and a tilt angle ⁇ 5 in the front-rear direction of the vehicle body 1 in relation to the global coordinate.
  • FIG. 4A is a block diagram illustrating a functional configuration of the control system 200 according to the present embodiment.
  • the control system 200 controls an excavation process of using the work machine 2 .
  • the control of excavation process includes limited excavation control.
  • the control system 200 includes the first cylinder stroke sensor 16 , the second cylinder stroke sensor 17 , the third cylinder stroke sensor 18 , the antenna 21 , the global coordinate calculating unit 23 , the IMU 24 , an operating device 25 , a work machine controller 26 , pressure sensors 66 and 67 , a control valve 27 , a direction control valve 64 , the display controller 28 , a display unit 29 , a sensor controller 30 , and a man machine interface 32 that sets an operation mode.
  • the operating device 25 is disposed in the cab 4 .
  • the operating device 25 is operated by an operator.
  • the operating device 25 receives an operator operation that drives the work machine 2 .
  • the operating device 25 is a pilot hydraulic-type operating device.
  • oil supplied to hydraulic cylinders (the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 ) in order to operate the hydraulic cylinders will be appropriately referred to as operating oil.
  • the amount of operating oil supplied to the hydraulic cylinder is adjusted by the direction control valve 64 .
  • the direction control valve 64 operates with oil supplied.
  • oil supplied to the direction control valve 64 in order to operate the direction control valve 64 will be appropriately referred to as pilot oil.
  • pilot pressure of pilot oil will be appropriately referred to as pilot pressure.
  • the operating oil and the pilot oil may be delivered from the same hydraulic pump.
  • a portion of the operating oil delivered from the hydraulic pump is decompressed and the decompressed operating oil may be used as the pilot oil.
  • a hydraulic pump (main hydraulic pump) that delivers operating oil and a hydraulic pump (pilot hydraulic pump) that delivers pilot oil may be different hydraulic pumps.
  • the operating device 25 includes a first operating lever 25 R and a second operating lever 25 L.
  • the first operating lever 25 R is disposed on the right side of the driver's seat 4 S, for example.
  • the second operating lever 25 L is disposed on the left side of the driver's seat 4 S, for example.
  • the front-rear and left-right movements correspond to 2 -axis operations.
  • the boom 6 and the bucket 8 are operated by the first operating lever 25 R.
  • the operation in the front-rear direction of the first operating lever 25 R corresponds to an operation of the boom 6 , and a lowering operation and a raising operation of the boom 6 are executed according to the operation in the front-rear direction.
  • the operation in the left-right direction of the first operating lever 25 R corresponds to an operation of the bucket 8 , and an excavating operation and a releasing operation of the bucket 8 are executed according to the operation in the left-right direction.
  • the arm 7 and the revolving structure 3 are operated by the second operating lever 25 L.
  • the operation in the front-rear direction of the second operating lever 25 L corresponds to an operation of the arm 7 , and a raising operation and a lowering operation of the arm 7 are executed according to the operation in the front-rear direction.
  • the operation in the left-right direction of the second operating lever 25 L corresponds to revolving of the revolving structure 3 , and a right revolving operation and a left revolving operation of the revolving structure 3 are executed according to the operation in the left-right direction.
  • the raising operation of the boom 6 corresponds to a dumping operation.
  • the lowering operation of the boom 6 corresponds to an excavating operation.
  • the lowering operation of the arm 7 corresponds to an excavating operation.
  • the raising operation of the arm 7 corresponds to a dumping operation.
  • the lowering operation of the bucket 8 corresponds to an excavating operation.
  • the lowering operation of the arm 7 may be referred to as a bending operation.
  • the raising operation of the arm 7 may be referred to as an extending operation.
  • the pilot oil which has been delivered from the hydraulic pump and decompressed to pilot pressure by the pressure-reducing valve is supplied to the operating device 25 .
  • the pilot pressure is adjusted by the amount of operation of the operating device 25 , and the direction control valve 64 via which operating oil supplied to the hydraulic cylinders (the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 ) is driven with the pilot pressure.
  • the pressure sensors 66 and 67 are disposed in pilot pressure lines 450 .
  • the pressure sensors 66 and 67 detect the pilot pressure.
  • the detection results of the pressure sensors 66 and 67 are output to the work machine controller 26 .
  • the first operating lever 25 R is operated in the front-rear direction in order to drive the boom 6 .
  • the direction control valve 64 via which the operating oil supplied to the boom cylinder 10 for driving the boom 6 is driven according to an amount of operation (amount of boom operation) of the first operating lever 25 R in the front-rear direction.
  • the pressure generated in the sensor 66 during this lever operation is referred to an amount of boom lever operation MB.
  • the first operating lever 25 R is operated in the left-right direction in order to drive the bucket 8 .
  • the direction control valve 64 via which the operating oil supplied to the bucket cylinder 12 for driving the bucket 8 is driven according to the amount of operation (amount of bucket operation) of the first operating lever 25 R in the left-right direction.
  • the pressure generated in the sensor 66 during this lever operation is referred to as an amount of bucket lever operation MT.
  • the second operating lever 25 L is operated in the front-rear direction in order to drive the arm 7 .
  • the direction control valve 64 via which the operating oil supplied to the arm cylinder 11 for driving the arm 7 is driven according to an amount of operation (amount of arm operation) of the second operating lever 25 L in the front-rear direction.
  • the pressure generated in the sensor 66 during this lever operation is referred to as an amount of arm lever operation MA.
  • the second operating lever 25 L is operated in the left-right direction in order to drive the revolving structure 3 .
  • the direction control valve 64 via which the operating oil supplied to a hydraulic actuator for driving the revolving structure 3 is driven according to the amount of operation of the second operating lever 25 L in the left-right direction.
  • the operation in the left-right direction of the first operating lever 25 R may correspond to the operation of the boom 6
  • the operation in the front-rear direction may correspond to the operation of the bucket 8
  • the operation in the left-right direction of the second operating lever 25 L may correspond to the operation of the arm 7
  • the operation in the front-rear direction may correspond to the operation of the revolving structure 3 .
  • the control valve 27 operates in order to adjust the amount of operating oil supplied to the hydraulic cylinders (the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 ).
  • the control valve 27 operates based on a control signal from the work machine controller 26 .
  • the sensor controller 30 calculates a boom cylinder length based on a detection result of the first cylinder stroke sensor 16 .
  • the first cylinder stroke sensor 16 outputs a phase shift pulse associated with the revolving operation to the sensor controller 30 .
  • the sensor controller 30 calculates the boom cylinder length based on the phase shift pulse output from the first cylinder stroke sensor 16 .
  • the sensor controller 30 calculates an arm cylinder length based on a detection result of the second cylinder stroke sensor 17 .
  • the sensor controller 30 calculates a bucket cylinder length based on a detection result of the third cylinder stroke sensor 18 .
  • the sensor controller 30 calculates a tilt angle ⁇ 1 of the boom 6 with respect to the vertical direction of the revolving structure 3 from the boom cylinder length acquired based on the detection result of the first cylinder stroke sensor 16 .
  • the sensor controller 30 calculates a tilt angle ⁇ 2 of the arm 7 with respect to the boom 6 from the arm cylinder length acquired based on the detection result of the second cylinder stroke sensor 17 .
  • the sensor controller 30 calculates a tilt angle ⁇ 3 of the cutting edge 8 a of the bucket 8 with respect to the arm 7 from the bucket cylinder length acquired based on the detection result of the third cylinder stroke sensor 18 .
  • the tilt angle ⁇ 1 of the boom 6 , the tilt angle ⁇ 2 of the arm 7 , and the tilt angle ⁇ 3 of the bucket 8 may not be detected by the cylinder stroke sensors.
  • the tilt angle ⁇ 1 of the boom 6 may be detected by an angle detection device such as a rotary encoder.
  • the angle detection device detects a bending angle of the boom 6 with respect to the revolving structure 3 to detect the tilt angle ⁇ 1 .
  • the tilt angle ⁇ 2 of the arm 7 may be detected by an angle detection device attached to the arm 7 .
  • the tilt angle ⁇ 3 of the bucket 8 may be detected by an angle detection device attached to the bucket 8 .
  • FIG. 4B is a block diagram illustrating the work machine controller 26 , the display controller 28 , and the sensor controller 30 .
  • the sensor controller 30 acquires a cylinder length data L from the detection results of the first, second, and third cylinder stroke sensors 16 , 17 , and 18 .
  • the sensor controller 30 outputs the data of the tilt angle ⁇ 4 and the data of the tilt angle ⁇ 5 of the vehicle body 1 output from the IMU 24 .
  • the sensor controller 30 outputs the data of the tilt angles ⁇ 1 to ⁇ 3 and the data of the tilt angle ⁇ 5 of the respective work machines to the display controller 28 and the work machine controller 26 , respectively.
  • the detection results of the cylinder stroke sensors ( 16 , 17 , and 18 ) and the detection result of the IMU 24 are output to the sensor controller 30 , and the sensor controller 30 performs a predetermined calculating process.
  • the functions of the sensor controller 30 may be performed by the work machine controller 26 .
  • the detection results of the cylinder stroke sensors ( 16 , 17 , and 18 ) may be output to the work machine controller 26 , and the work machine controller 26 may calculate the cylinder lengths (the boom cylinder length, the arm cylinder length, and the bucket cylinder length) based on the detection results of the cylinder stroke sensors ( 16 , 17 , and 18 ).
  • the detection result of the IMU 24 may be output to the work machine controller 26 .
  • the display controller 28 includes a target construction information storage unit 28 A, a bucket position data generating unit 28 B, and a target excavation landform data generating unit 28 C.
  • the display controller 28 acquires the reference position data P and the revolving structure direction data Q from the global coordinate calculating unit 23 .
  • the display controller 28 acquires cylinder tilt data ⁇ 1 to ⁇ 3 from the sensor controller 30 .
  • the bucket position data generating unit 28 B generates bucket position data indicating a 3-dimensional position of the bucket 8 based on the reference position data P, the revolving structure direction data Q, and the cylinder tilt data ⁇ 1 to ⁇ 3 .
  • the bucket position data is cutting edge position data S indicating a 3-dimensional position of the cutting edge 8 a.
  • the target excavation landform data generating unit 28 C generates a target excavation landform U indicating a target shape of an excavation object using the cutting edge position data S and target construction information T (described later) stored in the target construction information storage unit 28 A. Moreover, the display controller 28 displays the target excavation landform U on the display unit 29 based on the target excavation landform U.
  • the display unit 29 is a monitor, for example, and displays various types of information of the excavator 100 .
  • the display unit 29 includes a human machine interface (HMI) monitor as a guidance monitor for information-oriented construction.
  • HMI human machine interface
  • the display controller 28 can calculate the local coordinate position when seen in the global coordinate system based on the detection result of the position detection device 20 .
  • the local coordinate system is a 3-dimensional coordinate system based on the excavator 100 .
  • the reference position of the local coordinate system is the reference position P 2 positioned at the revolution axis AX of the revolving structure 3 , for example.
  • the target construction information storage unit 28 A stores target construction information (3-dimensional designed landform data) T indicating a 3-dimensional designed landform which is a target shape of a work area.
  • the target construction information T includes coordinate data and angle data required in order to generate the target excavation landform (designed landform data) U indicating a designed landform which is a target shape of an excavation object.
  • the target construction information T may be supplied to the display controller 28 via a radio communication device, for example.
  • the target construction information T may be transmitted from a connection-type recording device such as a memory.
  • the target excavation landform data generating unit 28 C calculates the position P 3 of the bucket cutting edge 8 a in the global coordinate system in relation to the reference position P 2 of the global coordinate system from the tilt angle ⁇ 1 of the boom 6 , the tilt angle ⁇ 2 of the arm 7 , the tilt angle ⁇ 3 of the bucket 8 , the length L 1 of the boom 6 , the length L 2 of the arm 7 , the length L 3 of the bucket 8 , and the position information of the boom pin 13 .
  • the target excavation landform data generating unit 28 C acquires a nodal line E between the 3-dimensional designed landform and a working plane MP of the work machine 2 defined in the front-rear direction of the revolving structure 3 as illustrated in FIG.
  • the target excavation landform data generating unit 28 C sets a point of the candidate line of the target excavation landform U located immediately below the bucket cutting edge 8 a as a reference point AP of the target excavation landform U.
  • the target excavation landform data generating unit 28 C determines a single or a plurality of inflection points appearing before and after the reference point AP of the target excavation landform U and lines appearing before and after the inflection points as the target excavation landform U which serves as an excavation object.
  • the target excavation landform data generating unit 28 C generates the target excavation landform U indicating a designed landform which is a target shape of the excavation object. A relative distance d between the target excavation landform U and the cutting edge 8 a is acquired based on the target excavation landform U and the bucket cutting edge 8 a.
  • the target excavation landform data generating unit 28 C outputs the target excavation landform U, the bucket cutting edge 8 a, and the distance between the target excavation landform U and the bucket cutting edge 8 a to the display unit 29 .
  • the display unit 29 displays a positional relation between the target excavation landform and the bucket 8 as an image and displays the distance d between the target excavation landform U and the bucket cutting edge 8 a.
  • the target excavation landform data generating unit 28 C outputs the calculated target excavation landform U to the work machine controller 26 .
  • the man machine interface 32 includes an input unit and a display unit.
  • the display unit includes a monitor such as a flat panel display.
  • the input unit of the man machine interface 32 includes operation buttons arranged around the display unit of the man machine interface 32 .
  • the input unit of the man machine interface 32 may include a touch panel.
  • the man machine interface 32 may be referred to a multi-monitor 32 .
  • the input unit of the man machine interface 32 is operated by an operator.
  • a command signal generated according to operations on the input unit is output to the work machine controller 26 .
  • the work machine controller 26 controls the display unit of the man machine interface 32 to display predetermined information on the display unit.
  • the work machine controller 26 includes a target speed determining unit 52 that determines a target speed of the bucket 8 determined according to the amount of operation of the operating device 25 , a distance acquiring unit 53 , a speed limit determining unit 54 , a work machine control unit 57 , and an arm control unit 263 .
  • the work machine controller 26 derives the position P 3 of the cutting edge 8 a in the local coordinate system from the tilt angles ⁇ 1 , ⁇ 2 , and ⁇ 3 , the position information of the boom pin 13 , the angle ⁇ 5 output from the IMU 24 , the detection result of the position detection device 20 , and the position information of the antenna 21 with the aid of the sensor controller 30 .
  • the work machine controller 26 acquires the cutting edge position information independently from the display controller 28 .
  • the target speed determining unit 52 acquires the tilt angle ⁇ 5 in the front-rear direction of the vehicle body 1 and the amounts of operation MB, MA, and MT acquired from the sensor 66 as Vc_bm, Vc_am, and Vc_bk corresponding to the lever operation for driving the respective work machines of the boom 6 , the arm 7 , and the bucket 8 .
  • the distance acquiring unit 53 acquires the target excavation landform U from the display controller 28 .
  • the distance acquiring unit 53 calculates the distance d between the cutting edge 8 a of the bucket 8 and the target excavation landform U in the direction vertical to the target excavation landform U based on the cutting edge position data P 3 and the target excavation landform U.
  • the speed limit determining unit 54 limits the movement of the boom 6 based on the distance d and the target speed.
  • the work machine control unit 57 determines an intervention command CBI on an intervention valve 27 C with respect to a speed limit Vc_bm_lmt.
  • An intervention speed of the boom 6 is output according to the above commands, whereby the work machine controller 28 executes limited excavation control (intervention control).
  • the arm control unit 263 acquires the amount of operation MA of the arm 7 from the target speed determining unit 52 .
  • a speed limit Vc_am_lmt is output to the work machine control unit 57 .
  • the work machine control unit 57 outputs a deceleration command CA to the control valve 27 ( 27 A and 27 B) according to the speed limit Vc_am_lmt.
  • the limitation determination of the arm control unit 263 will be described in detail later.
  • FIG. 6 is a flowchart illustrating an example of limited excavation control according to the present embodiment.
  • the target excavation landform U is set (step SA 1 ).
  • the work machine controller 26 determines the target speed Vc of the work machine 2 (step SA 2 ).
  • the target speed Vc of the work machine 2 includes a boom target speed Vc_bm, an arm target speed Vc_am, and a bucket target speed Vc_bkt.
  • the boom target speed Vc_bm is the speed of the cutting edge 8 a when the boom cylinder 10 only is driven.
  • the arm target speed Vc_am is the speed of the cutting edge 8 a when the arm cylinder 11 only is driven.
  • the bucket target speed Vc_bkt is the speed of the cutting edge 8 a when the bucket cylinder 12 only is driven.
  • the boom target speed Vc_bm is calculated based on the amount of boom operation.
  • the arm target speed Vc_am is calculated based on the amount of arm operation.
  • the bucket target speed Vc_bkt is calculated based on the amount of bucket operation.
  • Target speed information that defines the relation between the amount of boom operation and the boom target speed Vc_bm is stored in a storage unit 264 of the work machine controller 26 .
  • the work machine controller 26 determines the boom target speed Vc_bm corresponding to the amount of boom operation based on the target speed information.
  • the target speed information is a map in which the magnitude of the boom target speed Vc_bm corresponding to the amount of boom operation, for example, is described.
  • the target speed information may be in the form of a table, a numerical expression, or the like.
  • the target speed information includes information that defines the relation between the amount of arm operation and the arm target speed Vc_am.
  • the target speed information includes information that defines the relation between the amount of bucket operation and the bucket target speed Vc_bkt.
  • the work machine controller 26 determines the arm target speed Vc_am corresponding to the amount of arm operation based on the target speed information.
  • the work machine controller 26 determines the bucket target speed Vc_bkt corresponding to the amount of bucket operation based on the target speed information.
  • the work machine controller 26 converts the boom target speed Vc_bm into a speed component (vertical speed component) Vcy_bm in the direction vertical to the surface of the target excavation landform U and a speed component (horizontal speed component) Vcx_bm in the direction parallel to the surface of the target excavation landform U (step SA 3 ).
  • the work machine controller 26 calculates an inclination of the vertical axis (the revolution axis AX of the revolving structure 3 ) of the local coordinate system with respect to the vertical axis of the global coordinate system and an inclination in the vertical direction of the surface of the target excavation landform U with respect to the vertical axis of the global coordinate system from the reference position data P, the target excavation landform U, and the like.
  • the work machine controller 26 calculates an angle ⁇ 1 indicating the inclination between the vertical axis of the local coordinate system and the vertical direction of the surface of the target excavation landform U from these inclinations.
  • the work machine controller 26 converts the boom target speed Vc_bm into a speed component VL 1 _bm in the vertical axis direction of the local coordinate system and a speed component VL 2 _bm in the horizontal axis direction according to the theorem of trigonometric function from an angle ⁇ 2 between the vertical axis of the local coordinate system and the direction of the boom target speed Vc_bm.
  • the work machine controller 26 converts the speed component VL 1 _bm in the vertical axis direction of the local coordinate system and the speed component VL 2 _bm in the horizontal axis direction into a vertical speed component Vcy_bm and a horizontal speed component Vcx_bm with respect to the target excavation landform U according to the theorem of trigonometric function from the inclination ⁇ 1 between the vertical axis of the local coordinate system and the vertical direction of the surface of the target excavation landform U.
  • the work machine controller 26 converts the arm target speed Vc_am into a vertical speed component Vcy_am and a horizontal speed component Vcx_am in the vertical axis direction of the local coordinate system.
  • the work machine controller 26 converts the bucket target speed Vc_bkt into a vertical speed component Vcy_bkt and a horizontal speed component Vcx_bkt in the vertical axis direction of the local coordinate system.
  • the work machine controller 26 acquires the distance d between the cutting edge 8 a of the bucket 8 and the target excavation landform U (step SA 4 ).
  • the work machine controller 26 calculates the shortest distance d between the surface of the target excavation landform U and the cutting edge 8 a of the bucket 8 from the position information of the cutting edge 8 a, the target excavation landform U, and the like.
  • the limited excavation control is executed based on the shortest distance d between the surface of the target excavation landform U and the cutting edge 8 a of the bucket 8 .
  • the work machine controller 26 calculates an overall speed limit Vcy_lmt of the work machine 2 based on the distance d between the surface of the target excavation landform U and the cutting edge 8 a of the bucket 8 (step SA 5 ).
  • the overall speed limit Vcy_lmt of the work machine 2 is an allowable moving speed of the cutting edge 8 a in the direction in which the cutting edge 8 a of the bucket 8 approaches the target excavation landform U.
  • Speed limit information that defines the relation between the distance d and the speed limit Vcy_lmt is stored in the storage unit 264 of the work machine controller 26 .
  • FIG. 11 illustrates an example of the speed limit information according to the present embodiment.
  • the horizontal axis is the distance d and the vertical axis is the speed limit Vcy_lmt.
  • the distance d has a positive value when the cutting edge 8 a is positioned on the outer side of the surface of the target excavation landform U (that is, on the side close to the work machine 2 of the excavator 100 ), and the distance d has a negative value when the cutting edge 8 a is positioned on the inner side of the surface of the target excavation landform U (that is, on the inner side of the excavation object than the target excavation landform U).
  • the horizontal axis is the distance d
  • the vertical axis is the speed limit Vcy_lmt.
  • the distance d has a positive value when the cutting edge 8 a is positioned above the surface of the target excavation landform U.
  • the distance d has a negative value when the cutting edge 8 a is positioned under the surface of the target excavation landform U.
  • the distance d has a positive value when the cutting edge 8 a is positioned at such a position that the cutting edge 8 a does not dig into the target excavation landform U.
  • the distance d has a negative value when the cutting edge 8 a is positioned at such a position that the cutting edge 8 a digs into the target excavation landform U.
  • the distance d is 0 when the cutting edge 8 a is positioned on the target excavation landform U (that is, when the cutting edge 8 a is in contact with the target excavation landform U).
  • the speed has a positive value when the cutting edge 8 a moves from the inner side of the target excavation landform U toward the outer side, and the speed has a negative value when the cutting edge 8 a moves from the outer side of the target excavation landform U toward the inner side. That is, the speed has a positive value when the cutting edge 8 a moves toward the upper side of the target excavation landform U, and the speed has a negative value when the cutting edge 8 a moves toward the lower side of the target excavation landform U.
  • an inclination of the speed limit Vcy_lmt when the distance d is between d 1 and d 2 is smaller than an inclination when the distance d is equal to or larger than d 1 or equal to or smaller than d 2 .
  • d 1 is larger than 0.
  • d 2 is smaller than 0.
  • the inclination when the distance d is between d 1 and d 2 is smaller than the inclination when the distance d is equal to or larger than d 1 or equal to or smaller than d 2 .
  • the speed limit Vcy_lmt has a negative value when the distance d is equal to or larger than d 1 , and the larger the distance d, the smaller the speed limit Vcy_lmt. That is, when the distance d is equal to or larger than d 1 , the farther the cutting edge 8 a above the target excavation landform U from the surface of the target excavation landform U, the larger the speed of moving toward the lower side of the target excavation landform U and the larger the absolute value of the speed limit Vcy_lmt. When the distance d is equal to or smaller than 0, the speed limit Vcy_lmt has a positive value, and the smaller the distance d, the larger the speed limit Vcy_lmt.
  • the speed limit Vcy_lmt is Vmin.
  • the predetermined value dth 1 is a positive value and is larger than d 1 .
  • Vmin is smaller than a smallest value of the target speed. That is, when the distance d is equal to or larger than the predetermined value dth 1 , the operation of the work machine 2 is not limited.
  • the cutting edge 8 a is separated greatly from the target excavation landform U on the upper side of the target excavation landform U, the operation of the work machine 2 is not limited (that is, the limited excavation control is not performed).
  • the distance d is smaller than the predetermined value dth 1
  • the operation of the work machine 2 is limited.
  • the operation of the boom 6 is limited.
  • the work machine controller 26 calculates a vertical speed component (limited vertical speed component) Vcy_bm_lmt of the speed limit of the boom 6 from the overall speed limit Vcy_lmt of the work machine 2 , the arm target speed Vc_am, and the bucket target speed Vc_bkt (step SA 6 ).
  • the work machine controller 26 calculates the limited vertical speed component Vcy_bm_lmt of the boom 6 by subtracting the vertical speed component Vcy_am of the arm target speed and the vertical speed component Vcy_bkt of the bucket target speed from the overall speed limit Vcy_lmt of the work machine 2 .
  • the work machine controller 26 converts the limited vertical speed component Vcy_bm_lmt of the boom 6 into a speed limit (boom speed limit) Vc_bm_lmt (step SA 7 ).
  • the work machine controller 26 obtains a relation between a direction vertical to the surface of the target excavation landform U and the direction of the boom speed limit Vc_bm_lmt from a rotation angle a of the boom 6 , a rotation angle ⁇ of the arm 7 , a rotation angle of the bucket 8 , vehicle body position data P, the target excavation landform U, and the like and converts the limited vertical speed component Vcy_bm_lmt of the boom 6 into a boom speed limit Vc_bm_lmt.
  • This calculation is performed in a reverse order to that of the calculation of calculating the vertical speed component Vcy_bm in the direction vertical to the surface of the target excavation landform U from the boom target speed Vc_bm. After that, a cylinder speed corresponding to a boom intervention amount is determined, and a release command corresponding to the cylinder speed is output to the intervention valve 27 C described later.
  • the pilot pressure based on the lever operation is filled in an oil passage 451 B and the pilot pressure based on boom intervention is filled in an oil passage 502 .
  • a shuttle valve 51 (described later) selects the larger pressure (step SA 8 ).
  • the work machine controller 26 controls the work machine 2 .
  • the work machine controller 26 controls the boom cylinder 10 by transmitting a boom command signal to the intervention valve 27 C.
  • the boom command signal has a current value corresponding to a boom command speed.
  • the shuttle valve 51 selects the supply of operating oil from the oil passage 451 B, and a normal operation is performed (step SA 9 ).
  • the work machine controller 26 operates the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 according to the amount of boom operation, the amount of arm operation, and the amount of bucket operation, respectively.
  • the boom cylinder 10 operates at the boom target speed Vc_bm.
  • the arm cylinder 11 operates at the arm target speed Vc_am.
  • the bucket cylinder 12 operates at the bucket target speed Vc_bkt.
  • the shuttle valve 51 selects the supply of operating oil from an oil passage 502 , and the limited excavation control is executed (step SA 10 ).
  • the limited vertical speed component Vcy_bm_lmt of the boom 6 is calculated by subtracting the vertical speed component Vcy_am of the arm target speed and the vertical speed component Vcy_bkt of the bucket target speed from the overall speed limit Vcy_lmt of the work machine 2 .
  • the limited vertical speed component Vcy_bm_lmt of the boom 6 has a negative value, in which case the boom is raised.
  • the work machine controller 27 lowers the boom 6 at a speed lower than the boom target speed Vc_bm.
  • the boom speed limit Vc_bm_lmt has a positive value.
  • the work machine controller 26 raises the boom 6 .
  • FIG. 14 illustrates an example of a change in the speed limit of the boom 6 when the distance d between the target excavation landform U and the cutting edge 8 a of the bucket 8 is smaller than the predetermined value dth 1 and the cutting edge 8 a of the bucket 8 moves from the position Pn 1 to the position Pn 2 .
  • the distance between the cutting edge 8 a and the target excavation landform U at the position Pn 2 is smaller than the distance between the cutting edge 8 a and the target excavation landform U at the position Pn 1 . Due to this, the limited vertical speed component Vcy_bm_lmt 2 of the boom 6 at the position Pn 2 is smaller than the limited vertical speed component Vcy_bm_lmt 1 of the boom 6 at the position Pn 1 .
  • the boom speed limit Vc_bm_lmt 2 at the position Pn 2 is smaller than the boom speed limit Vc_bm_lmt 1 at the position Pn 1 .
  • the limited horizontal speed component Vcx_bm_lmt 2 of the boom 6 at the position Pn 2 is smaller than the limited horizontal speed component Vcx_bm_lmt 1 of the boom 6 at the position Pn 1 .
  • the arm target speed Vc_am and the bucket target speed Vc_bkt are not limited. Due to this, the vertical speed component Vcy_am and the horizontal speed component Vcx_am of the arm target speed and the vertical speed component Vcy_bkt and the horizontal speed component Vcx_bkt of the bucket target speed are not limited.
  • the present embodiment can suppress the sense of incongruity during the excavation operation of the operator while suppressing expansion of a digging area of the target excavation landform U.
  • the work machine controller 26 limits the speed of the boom 6 based on the target excavation landform U indicating the designed landform which is a target shape of an excavation object and the cutting edge position data S indicating the position of the cutting edge 8 a of the bucket 8 so that a relative speed at which the bucket 8 approaches the target excavation landform U decreases according to the distance d between the target excavation landform U and the cutting edge 8 a of the bucket 8 .
  • the work machine controller 26 determines the speed limit according to the distance d between the target excavation landform U and the cutting edge 8 a of the bucket 8 based on the target excavation landform U indicating the designed landform which is a target shape of an excavation object and the cutting edge position data S indicating the position of the cutting edge 8 a of the bucket 8 and controls the work machine 2 so that the speed in the direction in which the work machine 2 approaches the target excavation landform U is equal to or smaller than the speed limit. In this way, limited excavation control on the cutting edge 8 a is executed, and the position of the cutting edge 8 a in relation to the target excavation landform U is controlled.
  • intervention control outputting a control signal to the control valve 27 connected to the boom cylinder 10 to control the position of the boom 6 so that digging of the cutting edge 8 a into the target excavation landform U is suppressed is referred to as intervention control.
  • the intervention control is executed when the relative speed of the cutting edge 8 a in the vertical direction in relation to the target excavation landform U is larger than the speed limit.
  • the intervention control is not executed when the relative speed of the cutting edge 8 a is smaller than the speed limit.
  • the fact that the relative speed of the cutting edge 8 a is smaller than the speed limit includes the fact that the bucket 8 moves in relation to the target excavation landform U so that the bucket 8 is separated from the target excavation landform U.
  • the work machine controller 26 controls the arm 7 and the bucket 8 .
  • the work machine controller 26 transmits an arm command signal CA to the control valve 27 ( 27 A and 27 B) to thereby limit the supply of pilot pressure that drives the arm cylinder 11 .
  • the arm command signal CA has a current value corresponding to an arm command speed.
  • the work machine controller 26 transmits a bucket command signal to the control valve 27 to thereby control the bucket cylinder 12 similarly to the arm cylinder 11 .
  • the bucket command signal has a current value corresponding to a bucket command speed.
  • the cylinder stroke sensor 16 will be described with reference to FIGS. 15 and 16 .
  • the cylinder stroke sensor 16 attached to the boom cylinder 10 is described.
  • the cylinder stroke sensor 17 and the like attached to the arm cylinder 11 have the same configuration as the cylinder stroke sensor 16 .
  • the cylinder stroke sensor 16 is attached to the boom cylinder 10 .
  • the cylinder stroke sensor 16 measures the stroke of a piston.
  • the boom cylinder 10 includes a cylinder tube 10 X and a cylinder rod 10 Y configured to move within the cylinder tube 10 X in relation to the cylinder tube 10 X.
  • a piston 10 V is slidably provided in the cylinder tube 10 X.
  • the cylinder rod 10 Y is attached to the piston 10 V.
  • the cylinder rod 10 Y is slidably provided in a cylinder head 10 W.
  • a chamber formed by the cylinder head 10 W, the piston 10 V, and a cylinder inner wall is a rod-side oil chamber 40 B.
  • An oil chamber on the opposite side of the rod-side oil chamber 40 B with the piston 10 V interposed is a cab-side oil chamber 40 A.
  • a seal member is provided in the cylinder head 10 W so as to seal the gap between the cylinder head 10 W and the cylinder rod 10 Y so that dust or the like does not enter into the rod-side oil chamber 40 B.
  • the cylinder rod 10 Y retracts when operating oil is supplied to the rod-side oil chamber 40 B and the operating oil is discharged from the cab-side oil chamber 40 A. Moreover, the cylinder rod 10 Y extends when operating oil is discharged from the rod-side oil chamber 40 B and the operating oil is supplied to the cab-side oil chamber 40 A. That is, the cylinder rod 10 Y moves linearly in the left-right direction in the figure.
  • a case 164 that covers the cylinder stroke sensor 16 and accommodates the cylinder stroke sensor 16 is provided outside the rod-side oil chamber 40 B at the proximity of the cylinder head 10 W.
  • the case 164 is fixed to the cylinder head 10 W by being fastened to the cylinder head 10 W by bolts or the like.
  • the cylinder stroke sensor 16 includes a rotation roller 161 , a rotation center shaft 162 , and a rotation sensor portion 163 .
  • the rotation roller 161 has a surface in contact with the surface of the cylinder rod 10 Y and is provided so as to rotate according to linear movement of the cylinder rod 10 Y. That is, linear movement of the cylinder rod 10 Y is converted into rotational movement by the rotation roller 161 .
  • the rotation center shaft 162 is disposed to be orthogonal to the direction of linear movement of the cylinder rod 10 Y.
  • the rotation sensor portion 163 is configured to detect the amount of rotation (rotation angle) of the rotation roller 161 as an electrical signal.
  • the electrical signal indicating the amount of rotation (rotation angle) of the rotation roller 161 detected by the rotation sensor portion 163 is output to the sensor controller 30 via an electrical signal line.
  • the sensor controller 30 converts the electrical signal into the position (stroke position) of the cylinder rod 10 Y of the boom cylinder 10 .
  • the rotation sensor portion 163 includes a magnet 163 a and a hall IC 163 b.
  • the magnet 163 a which is a detecting medium is attached to the rotation roller 161 so as to rotate integrally with the rotation roller 161 .
  • the magnet 163 a rotates with rotation of the rotation roller 161 around the rotation center shaft 162 .
  • the magnet 163 a is configured such that the N pole and the S pole alternate according to the rotation angle of the rotation roller 161 .
  • the magnet 163 a is configured such that magnetic force (magnetic flux density) detected by the hall IC 163 b changes periodically every rotation of the rotation roller 161 .
  • the hall IC 163 b is a magnetic force sensor that detects the magnetic force (magnetic flux density) generated by the magnet 163 a as an electrical signal.
  • the hall IC 163 b is provided along the axial direction of the rotation center shaft 162 at a position separated by a predetermined distance from the magnet 163 a.
  • the electrical signal (phase shift pulse) detected by the hall IC 163 b is output to the sensor controller 30 .
  • the sensor controller 30 converts the electrical signal from the hall IC 163 b into an amount of rotation of the rotation roller 161 (that is, a displacement amount (boom cylinder length) of the cylinder rod 10 Y of the boom cylinder 10 ).
  • FIG. 16 a relation between the rotation angle of the rotation roller 161 and the electrical signal (voltage) detected by the hall IC 163 b will be described.
  • the rotation roller 161 rotates and the magnet 163 a rotates with the rotation, the magnetic force (magnetic flux density) that passes through the hall IC 163 b changes periodically according to the rotation angle and the electrical signal (voltage) which is the sensor output changes periodically.
  • the rotation angle of the rotation roller 161 can be measured from the magnitude of the voltage output from the hall IC 163 b.
  • the displacement amount (boom cylinder length) of the cylinder rod 10 Y of the boom cylinder 10 is calculated based on the rotation angle of the rotation roller 161 and the number of rotations of the rotation roller 161 .
  • the sensor controller 30 can calculate the moving speed (cylinder speed) of the cylinder rod 10 Y based on the rotation angle of the rotation roller 161 and the number of rotations of the rotation roller 161 .
  • the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 are hydraulic cylinders.
  • the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 will be appropriately collectively referred to as a hydraulic cylinder 60 .
  • FIG. 17 is a schematic diagram illustrating an example of the control system 200 according to the present embodiment.
  • FIG. 18 is an enlarged view of a portion of FIG. 17 .
  • a hydraulic system 300 includes the hydraulic cylinder 60 including the boom cylinder 10 , the arm cylinder 11 , and the bucket cylinder 12 and a revolving motor 63 that allows the revolving structure 3 to revolve.
  • the hydraulic cylinder 60 operates with operating oil supplied from a main hydraulic pump.
  • the revolving motor 63 is a hydraulic motor and operates with operating oil supplied from a main hydraulic pump.
  • the direction control valve 64 that controls the direction in which operating oil flows is provided.
  • the operating oil supplied from the main hydraulic pump is supplied to the hydraulic cylinder 60 via the direction control valve 64 .
  • the direction control valve 64 is a spool-type valve in which a rod-shaped spool is moved to change the flowing direction of operating oil.
  • the supply of operating oil to the cab-side oil chamber 40 A (the oil passage 48 ) and the supply of operating oil to the rod-side oil chamber 40 B (the oil passage 47 ) are switched.
  • the amount (the amount of supply per unit time) of operating oil supplied to the hydraulic cylinder 60 is adjusted.
  • the cylinder speed is adjusted.
  • a spool stroke sensor 65 that detects a moving distance (spool stroke) of the spool is provided in the direction control valve 64 . Although not illustrated in the figure, the detection signal of the spool stroke sensor 65 is output to the work machine controller 26 .
  • the driving of the direction control valve 64 is adjusted by the operating device 25 .
  • the operating device 25 is a pilot hydraulic-type operating device. Pilot oil which has been delivered from the main hydraulic pump and decompressed by the pressure-reducing valve is supplied to the operating device 25 . Pilot oil which has been delivered from a pilot hydraulic pump different from the main hydraulic pump may be supplied to the operating device 25 .
  • the operating device 25 includes a pilot pressure adjustment valve. The pilot pressure is adjusted based on the amount of operation of the operating device 25 .
  • the direction control valve 64 is driven with the pilot pressure. When the pilot pressure is adjusted by the operating device 25 , the movement amount and the moving speed of the spool in the axial direction are adjusted.
  • the direction control valve 64 is provided in each of the boom cylinder 10 , the arm cylinder 11 , the bucket cylinder 12 , and the revolving motor 63 .
  • the direction control valve 64 connected to the boom cylinder 10 will be appropriately referred to as a direction control valve 640 .
  • the direction control valve 64 connected to the arm cylinder 11 will be appropriately referred to as a direction control valve 641 .
  • the direction control valve 64 connected to the bucket cylinder 12 will be appropriately referred to as a direction control valve 642 .
  • the operating device 25 and the direction control valve 64 are connected by the pilot pressure lines 450 .
  • the control valve 27 , the pressure sensor 66 , and the pressure sensor 67 are disposed in the pilot pressure lines 450 .
  • pilot pressure line 450 between the operating device 25 and the control valve 27 will be appropriately referred to as an oil passage 451
  • a pilot pressure line 450 between the control valve 27 and the direction control valve 64 will be appropriately referred to as an oil passage 452 .
  • the oil passage 451 includes an oil passage 451 A that connects an oil passage 452 A and the operating device 25 and an oil passage 451 B that connects an oil passage 452 B and the operating device 25 .
  • the oil passages 451 A and 452 A are connected to the direction control valve.
  • the oil passage 452 is connected to the direction control valve 64 .
  • the pilot oil is supplied to the direction control valve 64 through the oil passage 452 .
  • the direction control valve 64 includes a first pressure receiving chamber and a second pressure receiving chamber.
  • the oil passage 452 includes the oil passage 452 A connected to the first pressure receiving chamber and the oil passage 452 B connected to the second pressure receiving chamber.
  • oil passage 452 A connected to the direction control valve 640 via which operating oil is supplied to the boom cylinder 10 will be appropriately referred to as an oil passage 4520 A
  • oil passage 452 B connected to the direction control valve 640 will be appropriately referred to as an oil passage 4520 B.
  • the oil passage 452 A connected to the direction control valve 641 via which operating oil is supplied to the arm cylinder 11 will be appropriately referred to as an oil passage 4521 A
  • the oil passage 452 B connected to the direction control valve 641 will be appropriately referred to as an oil passage 4521 B.
  • the oil passage 452 A connected to the direction control valve 642 via which operating oil is supplied to the bucket cylinder 12 will be appropriately referred to as an oil passage 4522 A
  • the oil passage 452 B connected to the direction control valve 642 will be appropriately referred to as an oil passage 4522 B.
  • the oil passage 451 A connected to the oil passage 4520 A will be appropriately referred to as an oil passage 4510 A
  • the oil passage 451 B connected to the oil passage 4520 B will be appropriately referred to as an oil passage 4510 B.
  • the oil passage 451 A connected to the oil passage 4521 A will be appropriately referred to as an oil passage 4511 A
  • the oil passage 451 B connected to the oil passage 4521 B will be appropriately referred to as an oil passage 4511 B
  • the oil passage 451 A connected to the oil passage 4522 A will be appropriately referred to as an oil passage 4512 A
  • the oil passage 451 B connected to the oil passage 4522 B will be appropriately referred to as an oil passage 4512 B.
  • the boom 6 executes two operations of the lowering operation and the raising operation.
  • pilot oil is supplied to the direction control valve 640 connected to the boom cylinder 10 through the oil passages 4510 B and 4520 B.
  • the direction control valve 640 operates based on pilot pressure. In this way, operating oil is supplied from the main hydraulic pump to the boom cylinder 10 , and the boom cylinder 10 is extended.
  • the raising operation of the boom 6 is executed according to extension of the boom cylinder.
  • pilot oil is supplied to the direction control valve 640 connected to the boom cylinder 10 through the oil passages 4510 A and 4520 A.
  • the direction control valve 640 operates based on pilot pressure. In this way, operating oil is supplied from the main hydraulic pump to the boom cylinder 10 , and the boom cylinder 10 is retracted. The lowering operation of the boom 6 is executed according to retraction of the boom cylinder.
  • the arm 7 executes two operations of the lowering operation and the raising operation.
  • pilot oil is supplied to the direction control valve 641 connected to the arm cylinder 11 through the oil passages 4511 B and 4521 B.
  • the direction control valve 641 operates based on pilot pressure. In this way, operating oil is supplied from the main hydraulic pump to the arm cylinder 11 , and the arm cylinder 11 is extended.
  • the lowering operation of the arm 7 is executed according to extension of the arm cylinder 11 .
  • pilot oil is supplied to the direction control valve 641 connected to the arm cylinder 11 through the oil passages 4511 A and 4521 A.
  • the direction control valve 641 operates based on pilot pressure. In this way, operating oil is supplied from the main hydraulic pump to the arm cylinder 11 , and the arm cylinder 11 is retracted. The raising operation of the arm 7 is executed according to retraction of the arm cylinder 11 .
  • the bucket 8 executes two operations of the lowering operation and the raising operation.
  • pilot oil is supplied to the direction control valve 642 connected to the bucket cylinder 12 through the oil passages 4512 B and 4522 B.
  • the direction control valve 642 operates based on pilot pressure. In this way, operating oil is supplied from the main hydraulic pump to the bucket cylinder 12 , and the bucket cylinder 12 is extended.
  • the lowering operation of the bucket 8 is executed according to extension of the bucket cylinder 12 .
  • pilot oil is supplied to the direction control valve 642 connected to the bucket cylinder 12 through the oil passages 4512 A and 4522 A.
  • the direction control valve 642 operates based on pilot pressure. In this way, operating oil is supplied from the main hydraulic pump to the bucket cylinder 12 , and the bucket cylinder 12 is retracted. The raising operation of the bucket 8 is executed according to retraction of the bucket cylinder 12 .
  • the revolving structure 3 executes two operations of the right revolving operation and the left revolving operation.
  • the operating oil is supplied to the revolving motor 63 .
  • the operating oil is supplied to the revolving motor 63 .
  • the control valve 27 adjusts pilot pressure based on a control signal (EPC current) from the work machine controller 26 .
  • the control valve 27 is an electromagnetic proportional control valve and is controlled based on a control signal from the work machine controller 26 .
  • the control valve 27 includes a control valve 27 A that can adjust the pilot pressure of pilot oil supplied to the first pressure receiving chamber of the direction control valve 64 to adjust the amount of operating oil supplied to the rod-side oil chamber 40 B via the direction control valve 64 and a control valve 27 B that can adjust the pilot pressure of pilot oil supplied to the second pressure receiving chamber of the direction control valve 64 to adjust the amount of operating oil supplied to the cab-side oil chamber 40 A via the direction control valve 64 .
  • the pressure sensors 66 and 67 that detect the pilot pressure are provided on both sides of the control valve 27 .
  • the pressure sensor 66 is disposed in the oil passage 451 between the operating device 25 and the control valve 27 .
  • the pressure sensor 67 is disposed in the oil passage 452 between the control valve 27 and the direction control valve 64 .
  • the pressure sensor 66 can detect the pilot pressure before being adjusted by the control valve 27 .
  • the pressure sensor 67 can detect the pilot pressure adjusted by the control valve 27 .
  • the detection results of the pressure sensors 66 and 67 are output to the work machine controller 26 .
  • control valves 27 capable of adjusting the pilot pressure of pilot oil to the direction control valve 640 via which operating oil is supplied to the boom cylinder 10 will be appropriately referred to as control valves 270 .
  • control valves 270 one set of control valves (corresponding to control valves 27 A) will be appropriately referred to as control valves 270 A, and the other set of control valves (corresponding to control valves 27 B) will be appropriately referred to as control valves 270 B.
  • the control valves 27 capable of adjusting the pilot pressure of pilot oil to the direction control valve 641 via which operating oil is supplied to the arm cylinder 11 will be appropriately referred to as control valves 271 .
  • control valves 271 one set of control valves (corresponding to control valves 27 A) will be appropriately referred to as control valves 271 A, and the other set of control valves (corresponding to control valves 27 B) will be appropriately referred to as control valves 271 B.
  • the control valves 27 capable of adjusting the pilot pressure of pilot oil to the direction control valve 642 via which operating oil is supplied to the bucket cylinder 12 will be appropriately referred to as control valves 272 .
  • control valves 272 one set of control valves (corresponding to control valves 27 A) will be appropriately referred to as control valves 272 A, and the other set of control valves (corresponding to control valves 27 B) will be appropriately referred to as control valves 272 B.
  • the pressure sensor 66 that detects the pilot pressure of the oil passage 451 connected to the direction control valve 640 via which operating oil is supplied to the boom cylinder 10 will be appropriately referred to as a pressure sensor 660
  • the pressure sensor 67 that detects the pilot pressure of the oil passage 452 connected to the direction control valve 640 will be appropriately referred to as a pressure sensor 670
  • the pressure sensor 660 disposed in the oil passage 4510 A will be appropriately referred to as a pressure sensor 660 A
  • the pressure sensor 660 disposed in the oil passage 4510 B will be appropriately referred to as a pressure sensor 660 B
  • the pressure sensor 670 disposed in the oil passage 4520 A will be appropriately referred to as a pressure sensor 670 A
  • the pressure sensor 670 disposed in the oil passage 4520 B will be appropriately referred to as a pressure sensor 670 B.
  • the pressure sensor 66 that detects the pilot pressure of the oil passage 451 connected to the direction control valve 641 via which operating oil is supplied to the arm cylinder 11 will be appropriately referred to as a pressure sensor 661
  • the pressure sensor 67 that detects the pilot pressure of the oil passage 452 connected to the direction control valve 641 will be appropriately referred to as a pressure sensor 671
  • the pressure sensor 661 disposed in the oil passage 4511 A will be appropriately referred to as a pressure sensor 661 A
  • the pressure sensor 661 disposed in the oil passage 4511 B will be appropriately referred to as a pressure sensor 661 B
  • the pressure sensor 671 disposed in the oil passage 4521 A will be appropriately referred to as a pressure sensor 671 A
  • the pressure sensor 671 disposed in the oil passage 4521 B will be appropriately referred to as a pressure sensor 671 B.
  • the pressure sensor 66 that detects the pilot pressure of the oil passage 451 connected to the direction control valve 642 via which operating oil is supplied to the bucket cylinder 12 will be appropriately referred to as a pressure sensor 662
  • the pressure sensor 67 that detects the pilot pressure of the oil passage 452 connected to the direction control valve 642 will be appropriately referred to as a pressure sensor 672
  • the pressure sensor 661 disposed in the oil passage 4512 A will be appropriately referred to as a pressure sensor 661 A
  • the pressure sensor 661 disposed in the oil passage 4512 B will be appropriately referred to as a pressure sensor 661 B
  • the pressure sensor 672 disposed in the oil passage 4522 A will be appropriately referred to as a pressure sensor 672 A
  • the pressure sensor 672 disposed in the oil passage 4522 B will be appropriately referred to as a pressure sensor 672 B.
  • the work machine controller 26 controls the control valve 27 to open the pilot pressure line 450 .
  • the pilot pressure line 450 is open, the pilot pressure of the oil passage 451 becomes the same as the pilot pressure of the oil passage 452 .
  • the pilot pressure is adjusted based on the amount of operation of the operating device 25 .
  • the work machine controller 26 When limited excavation control is performed and the work machine 2 is controlled by the work machine controller 26 , the work machine controller 26 outputs a control signal to the control valve 27 .
  • the oil passage 451 has a predetermined pressure due to the action of a pilot relief valve, for example.
  • the control valve 27 operates based on the control signal.
  • the operating oil of the oil passage 451 is supplied to the oil passage 452 via the control valve 27 .
  • the pressure of the operating oil of the oil passage 452 is adjusted (reduced) by the control valve 27 .
  • the pressure of the operating oil of the oil passage 452 acts on the direction control valve 64 .
  • the direction control valve 64 operates based on the pilot pressure controlled by the control valve 27 .
  • the pressure sensor 66 detects the pilot pressure before being adjusted by the control valve 27 .
  • the pressure sensor 67 detects the pilot pressure after being adjusted by the control valve 27 .
  • the work machine controller 26 can adjust the pilot pressure to the direction control valve 640 connected to the boom cylinder 10 by outputting a control signal to at least one of the control valves 270 A and 270 B.
  • the work machine controller 26 can adjust the pilot pressure to the direction control valve 641 connected to the arm cylinder 11 by outputting a control signal to at least one of the control valves 271 A and 271 B.
  • the work machine controller 26 can adjust the pilot pressure to the direction control valve 642 connected to the bucket cylinder 12 by outputting a control signal to at least one of the control valves 272 A and 272 B.
  • the work machine controller 26 limits the speed of the boom 6 based on the target excavation landform U indicating the designed landform which is a target shape of an excavation object and the bucket position data (cutting edge position data S) indicating the position of the bucket 8 so that a speed at which the bucket 8 approaches the target excavation landform U decreases according to the distance d between the target excavation landform U and the bucket 8 .
  • the work machine controller 26 includes a boom intervention unit that outputs a control signal for limiting the speed of the boom 6 .
  • the movement of the boom 6 is controlled (intervened) based on the control signal output from the boom intervention unit of the work machine controller 26 so that the cutting edge 8 a of the bucket 8 does not dig into the target excavation landform U.
  • the raising operation of the boom 6 is executed by the work machine controller 26 so that the cutting edge 8 a does not dig into the target excavation landform U.
  • the oil passage 502 is connected to the control valve 27 C that operates based on an intervention control signal output from the work machine controller 26 in order to perform intervention control.
  • the oil passage 501 is connected to the control valve 27 C so as to supply pilot oil to the direction control valve 640 connected to the boom cylinder 10 .
  • the oil passage 502 is connected to the control valve 27 C and the shuttle valve 51 and is connected to the oil passage 4520 B connected to the direction control valve 640 via the shuttle valve 51 .
  • the shuttle valve 51 has two inlet ports and one outlet port. One inlet port is connected to the oil passage 502 . The other inlet port is connected to the oil passage 4510 B. The outlet port is connected to the oil passage 4520 B.
  • the shuttle valve 51 connects an oil passage having a higher pilot pressure among the oil passages 502 and 4510 B to the oil passage 4520 B. For example, when the pilot pressure of the oil passage 502 is higher than the pilot pressure of the oil passage 4510 B, the shuttle valve 51 operates so that the oil passages 502 and 4520 B are connected and the oil passages 4510 B and 4520 B are not connected. In this way, the pilot oil of the oil passage 502 is supplied to the oil passage 4520 B via the shuttle valve 51 .
  • the shuttle valve 51 When the pilot pressure of the oil passage 4510 B is higher than the pilot pressure of the oil passage 502 , the shuttle valve 51 operates so that the oil passages 4510 B and 4520 B are connected and the oil passages 502 and 4520 B are not connected. In this way, the pilot oil of the oil passage 4510 B is supplied to the oil passage 4520 B via the shuttle valve 51 .
  • a pressure sensor 68 that detects the pilot pressure of the pilot oil of the oil passage 501 is provided in the oil passage 501 .
  • the pilot oil before passing through the control valve 27 C flows in the oil passage 501 .
  • the pilot oil having passed through the control valve 27 C flows in the oil passage 502 .
  • the control valve 27 C is controlled based on the control signal output from the work machine controller 26 in order to execute intervention control.
  • the work machine controller 26 When intervention control is not executed, the work machine controller 26 does not output a control signal to the control valve 27 so that the direction control valve 64 is driven based on the pilot pressure adjusted by the operation of the operating device 25 .
  • the work machine controller 26 opens the control valve 270 B to its full width and closes the control valve 27 C and the oil passage 501 so that the direction control valve 640 is driven based on the pilot pressure adjusted by the operation of the operating device 25 .
  • the work machine controller 26 controls the respective control valves 27 so that the direction control valve 64 is driven based on the pilot pressure adjusted by the control valve 27 C. For example, when intervention control of limiting the movement of the boom 6 is executed, the work machine controller 26 controls the control valve 27 C so that the pilot pressure adjusted by the control valve 27 C is higher than the pilot pressure adjusted by the operating device 25 . In this way, the pilot oil from the control valve 27 C is supplied to the direction control valve 640 via the shuttle valve 51 .
  • the intervention control is not executed.
  • the operating device 25 is operated so that the boom 6 is raised at a high speed and the pilot pressure is adjusted based on the amount of operation, the pilot pressure adjusted by the operation of the operating device 25 becomes higher than the pilot pressure adjusted by the control valve 27 C. In this way, the pilot oil having the pilot pressure adjusted by the operation of the operating device 25 is supplied to the direction control valve 640 via the shuttle valve 51 .
  • the work machine controller 26 determines that it is necessary to limit the excavation of the arm 7 , the work machine controller 26 outputs a command so that the amount of oil supplied to the control valve 271 B decreases. In this way, the supply of pilot pressure to the oil passage 4521 B according to the lever operation on the arm cylinder 11 is limited.
  • FIG. 19 is a diagram schematically illustrating an example of the operation of the work machine 2 when limited excavation control (boom intervention control) is performed.
  • the hydraulic system 300 includes the boom cylinder 10 for driving the boom 6 , the arm cylinder 11 for driving the arm 7 , and the bucket cylinder 12 for driving the bucket 8 .
  • the hydraulic system 300 operates so that the boom 6 is raised and the arm 7 is lowered.
  • intervention control including the raising operation of the boom 6 is executed so that the bucket 8 does not dig into the target excavation landform U.
  • load corresponding to the weight of the arm 7 and weight of the bucket 8 is applied to the arm cylinder 11
  • load corresponding to the weight of the boom 6 , the weight of the arm 7 , and the weight of the bucket 8 is applied to the boom cylinder 10
  • the load applied to the boom cylinder 10 is larger than the weight applied to the arm cylinder 11 .
  • the boom cylinder 10 needs to operate while resisting against the load. As a result, it may be difficult for the boom 6 to be moved appropriately (raised) in synchronization with the movement of the arm 7 so that the bucket 8 is suppressed from digging into the target excavation landform U.
  • the boom 6 is driven by the hydraulic cylinder (the boom cylinder) 10 . Due to this, it may be difficult for the boom 6 to satisfactorily follow the movement of the arm 7 . As a result, the bucket 8 may dig into the target excavation landform U and the excavation accuracy may decrease.
  • the work machine controller 26 performs limitation control on the arm 7 so that the arm 7 moves in synchronization with the movement of the boom 6 by taking a difference in the operating conditions (raising operation or lowering operation) of the boom 6 and the arm 7 and a difference in the load conditions of the boom cylinder 10 and the arm cylinder 11 during the excavation operation into consideration.
  • FIG. 20 is a functional block diagram illustrating an example of the control system 200 according to the present embodiment.
  • the control system 200 includes the operating device 25 operated in order to drive the arm 7 , a detection device 70 that detects the amount of operation MA (hereinafter simply M) of the operating device 25 , and the work machine controller 26 .
  • the work machine controller 26 includes a timer 261 that starts time measurement based on the detection result of the detection device 70 , a limit value setting unit 262 that sets a limited amount of operation Mr for limiting the speed of the arm 7 in association with the time elapsed from the start time of the time measurement of the timer 261 , the arm control unit 263 that generates a control signal N so that the arm 7 is driven with the limited amount of operation Mr in a predetermined period from the start of the time measurement of the timer 261 and outputs an arm speed limit Vc_am_lmt based on the control signal N, and the storage unit 264 .
  • the detection device 70 includes the pressure sensor 66 ( 661 B). The detection device 70 detects the amount of operation M of the operating device 25 by detecting the pilot pressure adjusted by the operating device 25 .
  • the work machine controller 26 limits the amount of operation (amount of arm operation) M of the operating device 25 and drives the arm 7 with the limited amount of operation Mr so that a delay in the raising intervention speed of the boom 6 in relation to the lowering speed of the arm 7 does not occur. That is, in the present embodiment, in the boom intervention control, the arm 7 is driven with the limited amount of operation Mr in at least a portion of the period where the boom 6 is raised and the arm 7 is lowered.
  • the limited amount of operation Mr is a value that can suppress a following delay of the boom 6 even when the arm 7 is operated with the limited amount of operation Mr.
  • the limited amount of operation Mr is obtained in advance through experiments or simulations and is stored in a memory (storage unit) of the work machine controller 26 .
  • the work machine controller 26 compares the amount of arm operation M detected by the detection device 70 with the limited amount of operation Mr.
  • the amount of arm operation M detected by the detection device 70 and the limited amount of operation Mr from the limit value setting unit 262 are output to the arm control unit 263 .
  • the arm control unit 263 includes a comparing unit. The comparing unit of the arm control unit 263 compares the amount of arm operation M with the limited amount of operation Mr.
  • the arm control unit 263 selects the smaller amount of operation among the amount of arm operation M and the limited amount of operation Mr based on a comparison result between the amount of arm operation M and the limited amount of operation Mr.
  • the arm control unit 263 outputs an arm speed limit Vc_am_lmt to the work machine control unit 57 so that the arm 7 is driven with the selected amount of operation among the amount of arm operation M and the limited amount of operation Mr.
  • arm speed limitation control control of limiting the operation (speed) of the arm 7 so that a delay in the raising intervention speed of the boom 6 in relation to the lowering speed of the arm 7 does not occur.
  • the selected amount of operation (the smaller amount of operation) among the amount of arm operation M and the limited amount of operation Mr will be appropriately referred to as an amount of operation Mf.
  • FIG. 21 is a flowchart for describing an example of the operation of the control system 200 according to the present embodiment.
  • FIGS. 22, 23, and 24 are timing charts for describing an example of the operation of the control system 200 according to the present embodiment.
  • the operating device 25 is operated by the operator (step SB 1 ).
  • the operator operates the operating device 25 in order to drive the arm 7 .
  • the operating device 25 is operated so that the arm 7 is lowered.
  • Intervention control on the boom 6 starts so that the bucket 8 does not dig into the target excavation landform U (step SB 2 ).
  • the speed of the boom 8 is limited based on the target excavation landform U indicating the target shape of an excavation object and the cutting edge position data S indicating the position of the cutting edge 8 a of the bucket 8 so that the speed at which the bucket 8 approaches the target excavation landform U decreases according to the distance d between the target excavation landform U and the bucket 8 .
  • the intervention control includes the raising operation of the boom 6 . With the intervention control on the boom 6 , the boom 6 is raised.
  • the amount of operation M of the operating device 25 is detected by the detection device 70 (step SB 3 ).
  • the detection device 70 includes the pressure sensor 66 and detects the amount of operation M of the operating device 25 by detecting the pilot pressure adjusted by the operating device 25 .
  • at least the pilot pressure (the pilot pressure of the oil passage 451 ) to the direction control valve 641 is detected by the pressure sensor 661 .
  • the detection value of the detection device 70 (the pressure sensor 661 ) is output to the timer 261 .
  • the timer 261 starts time measurement based on the detection result of the detection device 70 (step SB 4 ).
  • time t 0 is the start time of the time measurement of the timer 261 .
  • timer 261 starts the time measurement when the operating device 25 starts operating in order to drive the arm 7 . That is, time t 0 is the start time of the operation of the operating device 25 .
  • the start time of the time measurement of the timer 261 may be the time at which the detection value of the detection device 70 exceeds a threshold value.
  • the threshold value may be the value of the limited amount of operation Mr.
  • the start time of the time measurement of the timer 261 may be the time at which the amount (change rate) of increase per unit time of the detection value of the detection device 70 exceeds an allowable value.
  • the limit value setting unit 262 sets the limited amount of operation Mr for limiting the speed (lowering speed) of the arm 7 in association with the time elapsed from the start time t 0 of the time measurement of the timer 261 (step SB 5 ).
  • the limited amount of operation Mr is a value that can suppress the occurrence of a following delay of the boom 6 even when the arm 7 is operated with the limited amount of operation Mr.
  • the limited amount of operation Mr is obtained in advance through experiments or simulations.
  • the limited amount of operation Mr is set in association with the time elapsed from the start time t 0 of the time measurement of the timer 261 . In the following description, data indicating the limited amount of operation Mr set in association with time will be appropriately referred to as a limit pattern.
  • FIG. 22 illustrates a relation between the time elapsed from the start time t 0 and the amount of operation
  • FIG. 23 illustrates a relation between the time elapsed from the start time t 0 and the limited amount of operation Mr set by the limit value setting unit 262 . That is, FIG. 23 illustrates a limit pattern.
  • FIG. 24 illustrates a relation between the time elapsed from the start time t 0 and the amount of operation Mf of the arm 7 .
  • the start time t 0 is the start time of the time measurement of the timer 261 .
  • the horizontal axis is time (elapsed time).
  • the vertical axis is the amount of operation M of the arm 7 and the count value of the timer 261 .
  • the vertical axis is the limited amount of operation Mr and the count value of the timer 261 .
  • the vertical axis is the amount of operation Mf of the arm 7 and the count value of the timer 261 .
  • the relation between the time elapsed from the start time t 0 and the amount of operation M of the arm 7 by the operating device 25 is indicated by line S 1 .
  • the relation (limit pattern) between the time elapsed from the start time t 0 and the limited amount of operation Mr is indicated by line S 2 .
  • the relation (limit pattern) between the time elapsed from the start time t 0 and the amount of operation Mf is indicated by line Sc.
  • Line Lt indicates the count value of the timer 261 .
  • the line S 2 is depicted by a solid line and the line S 1 is depicted by a dot line.
  • the amounts of operation (M, Mr, and Mf) of the arm 7 are associated with the pilot pressure acting on the direction control valve 641 connected to the arm cylinder 11 .
  • the unit of the amounts of operation (M, Mr, and Mf) of the arm 7 is mega Pascal (MPa).
  • the pilot pressure corresponding to the amount of operation M is adjusted by the operating device 25 .
  • the pilot pressure corresponding to the limited amount of operation Mr is adjusted by the control valve 271 that is controlled by the arm control unit 263 .
  • the amount of operation M corresponds to the detection value of the pressure sensor 661 that detects the pilot pressure acting on the direction control valve 640 connected to the arm cylinder 11 .
  • the pressure sensor 661 outputs the detection value of the pilot pressure corresponding to the amount of operation M of the operating device 25 for driving the arm cylinder 11 .
  • the limited amount of operation Mr corresponds to a target value (limit value) of the pilot pressure acting on the direction control valve 640 connected to the arm cylinder 11 .
  • the correlation between the pilot pressure and the limited amount of operation Mr is obtained in advance and is stored in the storage unit 264 of the work machine controller 26 .
  • the arm control unit 263 determines the limited amount of operation Mr so that the target pilot pressure acts on the direction control valve 641 and generates a control signal N so that the pilot pressure corresponding to the limited amount of operation Mr is obtained.
  • the amount of operation Mf corresponds to the detection value of the pressure sensor 671 that detects the pilot pressure acting on the direction control valve 640 connected to the arm cylinder 11 .
  • the amount of operation Mf is the smaller amount of operation among the amount of operation M and the limited amount of operation Mr.
  • the arm control unit 263 does not generate the control signal N.
  • the control valve 271 is open to its full width and the pilot pressure based on the amount of operation M acts on the direction control valve 641 .
  • the arm control unit 263 When the amount of operation M is larger than the limited amount of operation Mr, the arm control unit 263 generates the control signal N to the control valve 271 so that the arm speed limitation control is executed based on the limited amount of operation Mr.
  • the pilot pressure based on the limited amount of operation Mr, adjusted by the control valve 271 acts on the direction control valve 641 .
  • FIG. 22 illustrates an example of the profile of the amount of operation M.
  • the profile of the amount of operation M is indicated by line Si.
  • the operating device 25 is operated by the operator in order to drive the arm 7 .
  • the timer 261 starts time measurement.
  • a case where the operating device 25 is operated by the operator so that the amount of operation M increases abruptly from 0 to value M 3 will be considered.
  • the amount of operation M maintains the value M 3 for a certain period after reaching the value M 3 and then decreases until it reaches 0.
  • the amount of operation M (Mf) has a profile indicated by the line S 1 of FIG. 22 .
  • a delay in the raising intervention speed of the boom 6 in relation to the lowering speed of the arm 7 may occur.
  • FIG. 23 illustrates an example of the profile of the limited amount of operation Mr.
  • the profile of the limited amount of operation Mr is indicated by line S 2 .
  • the limited amount of operation Mr is an amount of operation that is determined in advance so that a delay in the raising intervention speed of the boom 6 does not occur.
  • the value M 1 is set as a lower limit threshold value so that the limited amount of operation Mr is generated.
  • the limited amount of operation Mr is smaller than the amount of operation M.
  • the predetermined period Ts is a period between the time t 0 and the time t 1 .
  • the limited amount of operation Mr increases up to a value M 2 from 0. That is, in a period near the start time t 0 , the limited amount of operation Mr has the value M 2 .
  • the value M 2 is smaller than a value M 3 .
  • the limited amount of operation Mr maintains the value M 2 for a certain period after reaching the value M 2 , and increases gradually and reaches the value M 3 at the ending time t 1 . After that, the limited amount of operation Mr decreases until it reaches 0 at the time at which the amount of operation M based on the operation of the operator is smaller than the value M 1 after maintaining the value M 3 .
  • the limited amount of operation Mr is set to be smaller than the amount of operation M.
  • the value at the time t 0 which is the starting point of the limit pattern S 2 illustrated in FIG. 23 is M 2 and the value at the time t 1 which is the ending point of the limit pattern S 2 is M 3 .
  • the limited amount of operation Mr is the same as the amount of operation M. In this manner, in the present embodiment, the limited amount of operation Mr in the first half of the predetermined period Ts is smaller than the limited amount of operation Mr in the second half of the predetermined period Ts.
  • the arm control unit 263 compares the amount of operation M with the limited amount of operation Mr, selects the smaller amount of operation, and generates the control signal N based on the selected amount of operation Mf.
  • the limited amount of operation Mr is smaller than the amount of operation M.
  • the arm control unit 263 generates the control signal N so that the arm 7 is driven based on the limited amount of operation Mr.
  • the limited amount of operation Mr is set to the value M 3 .
  • the limited amount of operation Mr is the same as the amount of operation M.
  • the arm control unit 263 compares the amount of operation M with the limited amount of operation Mr and selects the amount of operation M. In the present embodiment, at the time t 1 , the arm speed limitation control ends.
  • the driving (arm speed limitation control) of the arm 7 based on the limited amount of operation Mr starts at the start time t 0 of the time measurement of the timer 261 and ends at the ending time t 1 after the elapse of the predetermined period Ts from the start time t 0 .
  • the driving based on the limited amount of operation Mr is disabled.
  • FIG. 24 illustrates an example of the profile of the amount of operation Mf.
  • the profile of the amount of operation Mf is indicated by the line Sc.
  • the arm 7 in the predetermined period Ts between the time t 0 and the time t 1 , the arm 7 is operated with the pilot pressure adjusted according to the limited amount of operation Mr as indicated by the line Sc. After the elapse of the predetermined period Ts, the arm 7 is operated with the pilot pressure adjusted according to the amount of operation M as indicated by the line Sc.
  • the profile of the amount of operation Mf of the arm 7 is determined so as to change along the line Sc of FIG. 24 .
  • the operation of the operating device 25 starts at the time t 0 , and the amount of operation Mf increases abruptly from 0 to the value M 2 and maintains the value M 2 for a certain period. After that, the amount of operation Mf increases gradually and reaches the value M 3 at the time t 1 . The amount of operation Mf maintains the value M 3 for a certain period after the time t 1 and then decreases to 0.
  • the arm control unit 263 generates the control signal N so that the arm 7 is driven with the limited amount of operation Mr in the predetermined period Ts from the start time t 0 of the time measurement of the timer 261 (step SB 6 ). That is, the arm control unit 263 generates the control signal N for driving the arm 7 so that the arm 7 is driven according to the profile of the limited amount of operation Mr in the predetermined period Ts.
  • the arm control unit 263 generates the control signal N so that the arm 7 is driven with the limited amount of operation Mr in the predetermined period Ts and stops generating the control signal N so that the arm 7 is driven with the amount of operation M after the elapse of the predetermined period Ts where the driving based on the limited amount of operation Mr is disabled. That is, the arm control unit 263 generates the control signal N so that the arm 7 moves at a low speed in the predetermined period Ts and the arm 7 moves at a high speed after the elapse of the predetermined period Ts.
  • the arm speed limit Vc_am_lmt is output based on the control signal N generated by the arm control unit 263 , and the arm operation command CA based on the arm speed limit Vc_am_lmt is output to the control valve 27 connected to the arm cylinder 11 .
  • the control valve 27 adjusts (limits) the pilot pressure based on the control signal N so that the amount of operating oil supplied to the arm cylinder 11 is adjusted (limited).
  • the cylinder speed is adjusted and the speed of the arm 7 is limited.
  • the arm control unit 263 suppresses the speed (lowering speed) of the arm 7 in the lowering operation of the arm 7 .
  • the speed of the arm 7 is limited in the predetermined period Ts, it is possible to suppress a decrease in the excavation accuracy even when the predetermined period Ts is not provided.
  • the speed of the arm 7 is limited in the intervention control (limited excavation control) of the boom 6 , a delay in the raising intervention speed of the boom 6 in relation to the excavation operation of the arm 7 is suppressed. Thus, a decrease in the excavation accuracy is suppressed.
  • the timer 261 performs time measurement, and the driving of the arm 7 is limited for the predetermined period Ts only from the start time t 0 of the time measurement of the timer 261 . Due to this, a decrease in the excavation accuracy is suppressed without complicating the control. Moreover, since the arm 7 is driven based on the operation of the operator after the elapse of the predetermined period Ts, a decrease in the workability is suppressed.
  • the start time (the start time of limiting the driving of the arm 7 ) t 0 of the time measurement of the timer 261 includes at least one of a start time of the operation of the operating device 25 , the time at which the detection value of the detection device 70 exceeds the threshold value, and the time at which the amount of increase per unit time of the detection value of the detection device 70 exceeds an allowable value. In this way, it is possible to smoothly limit the driving of the arm 7 in a period where a delay in the raising intervention speed of the boom 6 in relation to the excavation operation of the arm 7 is likely to occur.
  • the driving based on the limited amount of operation Mr is disabled after the elapse of the predetermined period Ts from the start time t 0 of the time measurement of the timer 261 . In this way, it is possible to perform a normal operation based on the amount of arm operation M of the operating device 25 .
  • the limited amount of operation Mr in the first half of the predetermined period Ts is smaller than the limited amount of operation Mr in the second half.
  • the limitation on the arm 7 is strengthened, whereby the occurrence of a following delay of the boom 6 is suppressed.
  • the limitation on the arm 7 is weakened, whereby a decrease in the operation efficiency is suppressed.
  • the arm 7 is driven with the limited amount of operation Mr in at least a portion of the period where the boom 6 is raised and the arm 7 is lowered. Due to this, even when the operating device 25 is operated at a high speed by the operator in order to drive the arm 7 , since the arm 7 moves at a limited speed (low speed), a delay in the raising intervention speed of the boom 6 in relation the excavation operation of the arm 7 is suppressed.
  • the arm speed limitation control it is possible to adjust the pilot pressure according to the control signal N to accurately adjust the amount of operating oil supplied to the arm cylinder 11 at a high speed.
  • the movement of the arm 7 is limited in order to suppress a following delay of the boom 6 .
  • the movement of the bucket 8 may be limited. That is, in the above-described embodiment, the operating device 25 may be operated in order to drive the bucket 8 , an amount of operation of the operating device 25 may be detected by the detection device 70 (the pressure sensor 662 ), the time measurement of the timer 261 may start based on the detection result of the detection device 70 , the limited amount of operation for limiting the speed of the bucket 8 may be set in association with the time elapsed from the start time of the time measurement of the timer 261 , a bucket control unit may be provided so that the bucket 8 is driven with a limited control amount in a predetermined period from the start time of the time measurement of the timer 261 , and a control signal may be output from the bucket control unit.
  • the detection device 70 the pressure sensor 662
  • the time measurement of the timer 261 may start based on the detection result of the detection device 70
  • the movement of both the arm 7 and the bucket 8 may be limited. The same is true for the following embodiments.
  • FIG. 25 is a schematic diagram illustrating an example of a control system 200 according to the present embodiment.
  • FIGS. 26, 27, and 28 are timing charts for describing an example of the operation of the control system 200 according to the present embodiment.
  • the control system 200 includes a variable capacitance hydraulic pump (main hydraulic pump) 41 that supplies operating oil, a direction control valve 641 ( 64 ) to which the operating oil from the hydraulic pump 41 is supplied, an arm cylinder 11 that is driven with the operating oil supplied from the hydraulic pump 41 via the direction control valve 641 , a pump controller (pump control unit) 49 that controls the hydraulic pump 41 , a mode setting unit 26 M, and a work machine controller 26 .
  • the pump controller 49 is connected to the work machine controller 26 .
  • the pump controller 49 outputs a control signal to a pump swash plate control device 41 C to control a pump swash plate of the hydraulic pump 41 .
  • the work machine controller 26 is connected to a man machine interface 32 .
  • the man machine interface 32 includes the mode setting unit 26 M.
  • the mode setting unit 26 M sets an operation mode of the excavator 100 based on the operation of the operator.
  • the mode setting unit 26 M stores information on a first operation mode and information on a second operation mode.
  • the mode setting unit may be provided with a switch or the like separately.
  • the control system 200 controls the excavator 100 in the first and second operation modes.
  • the first operation mode is an operation efficiency priority mode (P-mode).
  • the second operation mode is a fuel-saving mode (economy mode).
  • the supply of operating oil is limited so that a largest discharge capacity of operating oil from the hydraulic pump 41 , which is a second largest discharge capacity, is smaller than a largest discharge capacity of operating oil from the hydraulic pump 41 which is a first largest discharge capacity in the first operation mode.
  • both a limited amount of operation (the limited amount of operation for the first operation mode) Mr in the first operation mode and a limited amount of operation (the limited amount of operation for the second operation mode) Mr in the second operation mode are determined in advance and are stored in the storage unit 264 (not illustrated in FIG. 25 ) of the work machine controller 26 .
  • the work machine controller 26 When controlling the excavator 100 in the first operation mode, the work machine controller 26 performs arm speed limitation control using the limited amount of operation Mr in the first operation mode.
  • the work machine controller 26 performs arm speed limitation control using the limited amount of operation Mr in the second operation mode.
  • FIG. 26 illustrates a relation between the time elapsed from the start time t 0 in the first operation mode (P-mode) and the limited amount of operation Mr set by the limit value setting unit 262 .
  • a profile of the limited amount of operation Mr in the first operation mode is indicated by line S 2 .
  • FIG. 26 also illustrates a relation between the time elapsed from the start time t 0 and the amount of operation M of the arm 7 by the operating device 25 .
  • a profile of the amount of operation M is indicated by line S 1 .
  • the horizontal axis is time (elapsed time) and the vertical axis is the amount of operation (M, Mr) of the arm 7 and the count value of the timer 261 .
  • FIG. 27 illustrates a relation between the time elapsed from the start time t 0 in the second operation mode (economy mode) and the limited amount of operation Mr set by the limit value setting unit 262 .
  • a profile of the limited amount of operation Mr in the second operation mode is indicated by line S 3 .
  • FIG. 27 also illustrates the profile of the limited amount of operation Mr in the first operation mode by line S 2 .
  • the horizontal axis is time (elapsed time) and the vertical axis is the amount of operation (Mr) of the arm 7 and the count value of the timer 261 .
  • FIG. 28 illustrates a relation between the time elapsed from the start time t 0 in the second operation mode and the amount of operation Mf of the arm 7 as an example.
  • the horizontal axis is time (elapsed time) and the vertical axis is the amount of operation (Mf) of the arm 7 and the count value of the timer 261 .
  • the amount of operation M maintains the value M 3 for a certain period after reaching the value M 3 and then decreases until it reaches 0.
  • the amount of operation M (Mf) has a profile indicated by the line S 1 of FIG. 26 . In this case, a delay in the raising intervention speed of the boom 6 in relation to the excavation operation of the arm 7 may occur.
  • the line S 2 of FIG. 26 illustrates an example of the profile of the limited amount of operation Mr in the first operation mode.
  • the profile (limit pattern) of the limited amount of operation Mr in the first operation mode illustrated in FIG. 26 is equal to the profile of the limited amount of operation Mr described with reference to FIG. 23 . Description of the profile of the limited amount of operation Mr in the first operation mode will be omitted.
  • FIG. 27 illustrates an example of the profile of the limited amount of operation Mr in the second operation mode.
  • the profile of the limited amount of operation Mr in the second operation mode is indicated by line S 3 .
  • the limited amount of operation Mr in the second operation mode is an amount of operation that is determined in advance so that a following delay of the boom 6 does not occur.
  • the limited amount of operation Mr in the second operation mode is smaller than the limited amount of operation Mr and the amount of operation M in the first operation mode.
  • the driving of the arm 7 is controlled so that the arm 7 is not operated with the amount of operation M larger than the limited amount of operation Mr indicated by the line S 2 .
  • the driving of the arm 7 is controlled so that the arm 7 is not operated with the amount of operation M larger than the limited amount of operation Mr indicated by the line S 3 .
  • the predetermined period Ts is a period between the time t 0 and the time t 1 .
  • the limited amount of operation Mr in the second operation mode is 0 at time t 0 and increases from 0 to a value M 2 u.
  • the value M 2 u is larger than 0 and is smaller than the value M 2 . That is, in a period near the start time t 0 , the limited amount of operation Mr in the second operation mode has the value MM 2 u.
  • the limited amount of operation Mr in the second operation mode maintains the value M 2 u for a certain period after reaching the value MM 2 u, and increases gradually and reaches the value M 3 at the ending time t 1 . After that, the limited amount of operation Mr decreases until it reaches 0 after maintaining the value M 3 .
  • the limited amount of operation Mr in the second operation mode is set to be smaller than the limited amount of operation Mr and the amount of operation M in the first operation mode.
  • the value at the time t 0 which is the starting point of the limit pattern S 3 illustrated in FIG. 27 is M 2 u and the value at the time t 1 which is the ending point of the limit pattern S 2 is M 3 .
  • the limited amount of operation Mr in the second operation mode is the same as the amount of operation M.
  • the limited amount of operation Mr in the first half of the predetermined period Ts is smaller than the limited amount of operation Mr in the second half of the predetermined period Ts.
  • the arm control unit 263 compares the amount of operation M with the limited amount of operation Mr, selects the smaller amount of operation, and generates the control signal N based on the selected amount of operation Mf.
  • the limited amount of operation Mr is smaller than the amount of operation M.
  • the arm control unit 263 generates the control signal N so that the arm 7 is driven based on the limited amount of operation Mr.
  • the arm control unit 263 in the first operation mode, the arm control unit 263 outputs the control signal N to the control valve 271 so that the arm 7 is driven based on the limited amount of operation Mr for the first operation mode as indicated by the line S 2 of FIG. 26 .
  • the arm control unit 263 In the second operation mode, the arm control unit 263 generates the control signal N so that the arm 7 is driven based on the limited amount of operation Mr for the second operation mode indicated by the line S 3 of FIG. 27 .
  • the limited amount of operation Mr in the second operation mode is set to the value M 3 .
  • the limited amount of operation Mr in the second operation mode is the same as the amount of operation M.
  • the arm control unit 263 compares the amount of operation M with the limited amount of operation Mr and selects the amount of operation M. In the present embodiment, at the time t 1 , the arm speed limitation control ends.
  • the driving (arm speed limitation control) of the arm 7 based on the limited amount of operation Mr starts at the start time t 0 of the time measurement of the timer 261 and ends at the ending time t 1 after the elapse of the predetermined period Ts from the start time t 0 .
  • the driving based on the limited amount of operation Mr is disabled.
  • FIG. 28 illustrates an example of the profile of the amount of operation Mf in the second operation mode.
  • the profile of the amount of operation Mf in the second operation mode is indicated by the line Sc.
  • the arm 7 in the predetermined period Ts between the time t 0 and the time t 1 , the arm 7 is operated with the pilot pressure adjusted according to the limited amount of operation Mr for the second operation mode as indicated by the line Sc. After the elapse of the predetermined period Ts, the arm 7 is operated with the pilot pressure adjusted according to the amount of operation M as indicated by the line Sc.
  • the profile of the amount of operation Mf of the arm 7 is determined so as to change along the line Sc of FIG. 28 .
  • the operation of the operating device 25 starts at the time t 0 , and the amount of operation Mf increases abruptly from 0 to the value M 2 u and maintains the value M 2 u for a certain period. After that, the amount of operation Mf increases gradually and reaches the value M 3 at the time t 1 . The amount of operation Mf maintains the value M 3 for a certain period after the time t 1 and then decreases to 0.
  • the arm control unit 263 generates the control signal N so that the arm 7 is driven with the limited amount of operation Mr for the second operation mode in the predetermined period Ts from the start time t 0 of the time measurement of the timer 261 .
  • the arm control unit 263 generates the control signal N so that the arm 7 is driven with the limited amount of operation Mr for the second operation mode in the predetermined period Ts and stops generating the control signal N so that the arm 7 is driven with the amount of operation M after the elapse of the predetermined period Ts where the driving based on the limited amount of operation Mr for the second operation mode is disabled.
  • the arm 7 moves at a low speed in the predetermined period Ts and the arm 7 moves at a high speed after the elapse of the predetermined period Ts.
  • the limited amount of operation Mr in the second operation mode is smaller than the limited amount of operation Mr in the first operation mode.
  • the second operation mode is advantageous over the first operation mode in terms of fuel efficiency.
  • the amount of operating oil supplied to the hydraulic cylinder 60 decreases.
  • the possibility of the occurrence of a delay in the raising intervention speed of the boom 6 increases.
  • the limited amount of operation Mr in the second operation mode is smaller than the limited amount of operation Mr in the first operation mode. That is, in the second operation mode, the movement of the arm 7 is limited more strictly than the first operation mode. Due to this, the occurrence of a delay in the raising intervention speed of the boom is suppressed.
  • the bucket 8 is replaceable.
  • Various buckets 8 are connected to the distal end of the arm 7 .
  • the limited amount of operation Mr when the bucket 8 of the first weight is connected to the boom 6 with the arm 7 interposed is smaller than the limited amount of operation Mr when the bucket 8 of the second weight smaller than the first weight is connected to the boom 6 with the arm 7 interposed.
  • the limited amount of operation Mr when the bucket 8 of the first weight is connected is smaller than the limited amount of operation Mr when the bucket 8 of the second weight is connected. Due to this, it is possible to suppress the occurrence of a following delay of the boom 6 while suppressing a decrease in the workability.
  • FIG. 29 is a diagram illustrating an example of the amount of operation M and the limited amount of operation Mr.
  • the amount of operation M of the operating device 25 is derived from the detection result of the detection device 70 (the pressure sensor 661 ).
  • the amount of operation M derived from the detection result of the detection device 70 is compared with the limited amount of operation Mr (limit pattern) stored in the storage unit 264 .
  • the arm 7 is operated based on the amount of operation M of the operating device 25 .
  • the operating device 25 may be operated abruptly so that the amount of operation M increases abruptly to exceed the limited amount of operation Mr. In this case, even when the amount of operation M is compared with the limited amount of operation Mr and the speed of the arm 7 is limited based on the limited amount of operation Mr, the speed of the arm 7 may not be limited sufficiently.
  • the work machine controller 26 starts (restarts) the time measurement of the timer 261 and changes a portion of the limited amount of operation Mr to perform the arm speed limitation control.
  • the fact that the amount of operation M increases abruptly includes the fact that the amount of increase per unit time of the amount of operation M exceeds an allowable value.
  • the amount of operation M is derived from the detection result of the detection device 70 .
  • the fact that the amount of operation M increases abruptly includes the fact that the amount of increase per unit time of the detection value of the detection device 70 (the pressure sensor 661 ) exceeds an allowable value.
  • the work machine controller 26 restarts the time measurement of the timer 261 and changes a portion of the limited amount of operation Mr to perform the arm speed limitation control.
  • the amount of increase of the detection value of the detection device 70 is a difference (deviation) between the amount of operation M of the operating device 25 detected by the detection device 70 and a processing amount R generated from the amount of operation M by a low-pass filtering process.
  • FIG. 30 is a diagram illustrating an example of the control system 200 according to the present embodiment.
  • a detection value (the amount of operation M of the operating device 25 ) of the detection device 70 is output to the work machine controller 26 .
  • the detection value of the detection device 70 is output to a filtering device 71 .
  • the filtering device 71 can execute a first-order low-pass filtering process.
  • the filtering device 71 performs a first-order low-pass filtering process on the detection value of the detection device 70 and generates a processing amount R.
  • the work machine controller 26 calculates a deviation between the amount of operation M and the processing amount R.
  • FIG. 31 is a schematic view illustrating a relation between the amount of operation M and the processing amount R when the operating device 25 is operated abruptly (at a high speed). As illustrated in FIG. 31 , when the operating device 25 is operated abruptly and the amount of operation M increases in a stepwise manner, the deviation between the amount of operation M and the processing amount R is large.
  • FIG. 32 is a schematic view illustrating a relation between the amount of operation M and the processing amount R when the operating device 25 is operated smoothly (at a low speed). As illustrated in FIG. 32 , when the operating device 25 is operated smoothly and the amount of operation M increases smoothly, the deviation between the amount of operation M and the processing amount R is small.
  • the time measurement of the timer 261 starts (restarts).
  • FIG. 33 is a flowchart illustrating an example of the operation of the control system 200 according to the present embodiment.
  • FIGS. 34, 35, and 36 are timing charts for describing an example of the operation of the control system 200 according to the present embodiment.
  • the horizontal axis is time and the vertical axis is the amount of operation (M, Mr, and Mf) of the arm 7 and the count value of the timer.
  • step SC 1 when the operating device 25 starts operating the arm 7 , the time measurement of the timer 261 starts (step SC 1 ).
  • boom intervention control including the raising operation of the boom 6 is executed according to the distance d between the target designed landform U and the cutting edge 8 a (step SC 2 ).
  • the amount of operation M of the operating device 25 for driving the arm 7 is detected by the detection device 70 (the pressure sensor 661 ) (step SC 3 ).
  • the detection result of the amount of operation M is output to the comparing unit of the arm control unit 263 .
  • information on the limited amount of operation Mr is output from the limit value setting unit 262 to the comparing unit of the arm control unit 263 .
  • the arm control unit 263 compares the amount of operation M with the limited amount of operation Mr according to the above-described embodiment (step SC 4 ).
  • step SC 4 When it is determined in step SC 4 that the amount of operation M is larger than the limited amount of operation Mr (that is, Yes in step SC 4 ), the arm control unit 263 selects the limited amount of operation Mr and uses the same as the amount of operation Mf. The arm control unit 263 generates the control signal N based on the selected limited amount of operation Mr. In this way, the arm speed limitation control is performed based on the limited amount of operation Mr (step SC 5 ).
  • step SC 4 When it is determined in step SC 4 that the amount of operation M is equal to or smaller than the limited amount of operation Mr (that is, No in step SC 4 ), the arm control unit 263 selects the amount of operation M and uses the same as the amount of operation Mf. The arm control unit 263 does not generate the control signal N. The arm 7 is driven with the pilot pressure adjusted based on the amount of operation M of the operating device 25 (step SC 6 ).
  • FIG. 34 illustrates an example of the profile of the amount of operation M according to the present embodiment.
  • the profile of the amount of operation M is indicated by line S 1 .
  • the operating device 25 is operated by the operator in order to drive the arm 7 .
  • the timer 261 starts time measurement.
  • the present embodiment as an example, as indicated by the line S 1 of FIG. 34 , a case where the operating device 25 is operated by the operator so that the amount of operation M increases from 0 to value M 1 u will be considered.
  • the value M 1 u is smaller than a lower limit value M 1 of the amount of operation generated by the limited amount of operation Mr and the value M 2 of the limited amount of operation Mr.
  • the amount of operation M maintains the value M 1 u for a certain period after reaching the value M 1 u. In the present embodiment, in a period between time t 0 and time t 0 n, the amount of operation M maintains the value M 1 u.
  • the profile of the limited amount of operation Mr is indicated by line S 2 .
  • the limited amount of operation Mr indicated by the line S 2 is the same as the limited amount of operation Mr described with reference to FIG. 23 or the like. Detailed description of the limited amount of operation Mr indicated by the line S 2 will not be provided.
  • the limited amount of operation Mr indicated by the line S 2 has the value M 2 .
  • the limited amount of operation Mr is equal to or larger than the value M 2 . That is, in the example illustrated in FIG. 34 , in the period between the time t 0 and the time t 0 n, the amount of operation M does not exceed the limited amount of operation Mr indicated by the line S 2 .
  • the arm 7 is driven based on the amount of operation M of the operating device 25 .
  • the operating device 25 may be operated abruptly so that the amount of operation M increases abruptly as indicated by the line S 1 of FIG. 34 to exceed the limited amount of operation Mr indicated by the line S 2 .
  • the operating device 25 is operated abruptly and the amount of operation M increases abruptly.
  • the amount of operation M increases abruptly from the value M 1 u to the value M 3 v.
  • the value M 3 v is larger than the value M 3 .
  • the amount of increase of the detection value of the detection device 70 is a difference (deviation) between the amount of operation M of the operating device 25 detected by the detection device 70 and the processing amount R generated from the amount of operation M by a low-pass filtering process.
  • the detection device 70 determines whether a deviation between the amount of operation M and the processing amount R exceeds an allowable value (step SC 8 ).
  • step SC 8 When it is determined in step SC 8 that the deviation is equal to or smaller than the allowable value (that is, No in step SC 8 ), the flow returns to step SC 4 and the work machine controller 26 compares the increased amount of operation M with the limited amount of operation Mr and executes the above-described process.
  • step SC 8 When it is determined in step SC 8 that the deviation exceeds the allowable value (that is, Yes in step SC 8 ), the work machine controller 26 resets the time measurement from the time t 0 and starts (restarts) the time measurement of the timer 261 (step SC 9 ).
  • the limit value setting unit 262 resets the time measurement, resets the limited amount of operation Mr indicated by the line S 2 , and sets (resets) the limited amount of operation Mr in association with the time elapsed from the start time t 0 n of the time measurement of the timer 261 .
  • FIG. 35 illustrates an example of the profile of the reset limited amount of operation Mr.
  • the profile of the reset limited amount of operation Mr is indicated by line S 4 .
  • the limited amount of operation Mr is an amount of operation that is determined in advance so that the following delay of the boom 6 does not occur.
  • the limited amount of operation Mr is smaller than the amount of operation M indicated by the line S 1 of FIG. 34 .
  • the time measurement of the timer 261 restarts at the time t 0 n, the driving of the arm 7 is controlled so that the arm 7 is not operated with the amount of operation M larger than the limited amount of operation Mr in a predetermined period Tu where the timer 261 performs time measurement.
  • the predetermined period Tu is a period between the time t 0 n and the time t 3 .
  • the limited amount of operation Mr has a value M 2 .
  • M 2 is smaller than a value M 3 v.
  • the limited amount of operation Mr set to the value M 2 at the time t 0 n maintains the value M 2 for a certain period, and increases gradually and reaches the value M 3 at the time t 2 . After that, the limited amount of operation Mr decreases until it reaches 0 after maintaining the value M 3 until the time t 3 . In this manner, in the predetermined period Tu between the time t 0 n and the time t 3 , the limited amount of operation Mr is set to be smaller than the amount of operation M.
  • the value at the time t 0 n which is the starting point of the limit pattern S 4 illustrated in FIG. 35 is M 2
  • the value immediately before the time t 3 which is the ending point of the limit pattern S 4 is M 3
  • the value at the time t 3 is 0.
  • the limited amount of operation Mr in the first half of the predetermined period Tu is smaller than the limited amount of operation Mr in the second half of the predetermined period Tu.
  • the arm control unit 263 compares the amount of operation M with the reset limited amount of operation Mr (step SC 10 ).
  • step SC 10 When it is determined in step SC 10 that the amount of operation M is equal to or smaller than the limited amount of operation Mr (that is, step SC 10 :No), the arm control unit 263 selects the amount of operation M and uses the same as the amount of operation Mf. The arm control unit 263 does not generate the control signal N.
  • the arm 7 is driven with the pilot pressure adjusted based on the amount of operation M of the operating device 25 (step SC 11 ).
  • step SC 10 When it is determined in step SC 10 that the amount of operation M is larger than the limited amount of operation Mr (that is, Yes in step SC 10 ), the arm control unit 263 selects the reset limited amount of operation Mr indicated by the line S 4 and uses the same as the amount of operation Mf. The arm control unit 263 generates the control signal N based on the selected limited amount of operation Mr. In this way, the arm speed limitation control is performed based on the limited amount of operation Mr (step SC 12 ).
  • the amount of operation M is larger than the limited amount of operation Mr indicated by the line S 4 .
  • the arm control unit 263 performs arm speed limitation control based on the limited amount of operation Mr.
  • FIG. 36 illustrates an example of the profile of the amount of operation Mf according to the present embodiment.
  • the profile of the amount of operation Mf is indicated by line Sc.
  • the arm 7 is operated with the pilot pressure adjusted according to the amount of operation M as indicated by the line Sc. That is, the amount of operation Mf increases from 0 to the value M 1 u at the time t 0 and increases from the value M 1 u to the value M 2 at the time t 0 n after maintaining the value M 1 u until the time t 0 n.
  • the amount of operation Mf maintains the value M 2 for a predetermined period, increases gradually to reach the value M 3 at the time t 2 , and maintains the value M 3 until the time t 3 .
  • the time measurement of the timer 261 is reset and restarted, and the limit pattern S 4 in which the value at the starting point (time t 0 n ) is M 2 is set (reset).
  • the arm 7 is controlled smoothly and a decrease in the excavation accuracy is suppressed.
  • the amount of operation may increase abruptly to the value M 3 based on the limit pattern S 2 ni at the time t 0 n.
  • the speed of the arm 7 may increase abruptly, the intervention speed of the boom 6 may be slower than the raising speed of the arm 7 , and the excavation accuracy may decrease.
  • the time measurement of the timer 261 is reset to restart the time measurement, and a portion of the limit pattern S 2 is changed to set a new limit pattern S 4 .
  • FIG. 37 is a diagram illustrating an example of the amount of operation M and the limited amount of operation Mr.
  • the arm 7 is operated based on the limited amount of operation Mr.
  • the operating device 25 may be operated so that the amount of operation M decreases.
  • the arm 7 is driven so as to be accelerated. In this case, the operator may feel a sense of incongruity.
  • the work machine controller 26 determines that the amount of operation has decreased and maintains the limited amount of operation Mr to a certain value from the decrease start time tg.
  • the operating device 25 is operated so that the amount of operation M decreases, since the limited amount of operation Mr is maintained to a certain value, it is possible to suppress the sense of incongruity that the operator might feel.
  • FIG. 38 is a functional block diagram illustrating an example of the control system 200 according to the present embodiment.
  • FIG. 39 is a flowchart for describing an example of the operation of the control system 200 according to the present embodiment.
  • FIGS. 40, 41, and 42 are timing charts for describing an example of the operation of the control system 200 according to the present embodiment.
  • the horizontal axis is time and the vertical axis is the amount of operation (M, Mr, and Mf) of the arm 7 and the count value of the timer.
  • the arm control unit 263 has a comparing unit 263 A.
  • the comparing unit 263 A compares the amount of operation M with the limited amount of operation Mr according to the above-described embodiment.
  • step SD 1 when the operating device 25 starts operating the arm 7 , the time measurement of the timer 261 starts (step SD 1 ).
  • boom intervention control including the raising operation of the boom 6 is executed according to the distance d between the target designed landform U and the cutting edge 8 a (step SD 2 ).
  • the amount of operation M of the operating device 25 for driving the arm 7 is detected by the detection device 70 (the pressure sensor 661 ) (step SD 3 ).
  • the detection result of the amount of operation M is output to the comparing unit 263 A of the arm control unit 263 .
  • information on the limited amount of operation Mr is output from the limit value setting unit 262 to the comparing unit 263 A of the arm control unit 263 .
  • the arm control unit 263 compares the amount of operation M with the limited amount of operation Mr according to the above-described embodiment (step SD 4 ).
  • step SD 4 When it is determined in step SD 4 that the amount of operation M is larger than the limited amount of operation Mr (that is, Yes in step SD 4 ), the arm control unit 263 selects the limited amount of operation Mr and uses the same as the amount of operation Mf. The arm control unit 263 generates the control signal N based on the selected limited amount of operation Mr. In this way, the arm speed limitation control is performed based on the limited amount of operation Mr (step SD 5 ).
  • step SD 4 When it is determined in step SD 4 that the amount of operation M is equal to or smaller than the limited amount of operation Mr (that is, No in step SD 4 ), the arm control unit 263 selects the amount of operation M and uses the same as the amount of operation Mf. The arm control unit 263 does not generate the control signal N. The arm 7 is driven with the pilot pressure adjusted based on the amount of operation M of the operating device 25 (step SD 6 ).
  • FIG. 40 illustrates an example of the profile of the amount of operation M according to the present embodiment.
  • the profile of the amount of operation M is indicated by line S 1 .
  • the operating device 25 is operated by the operator in order to drive the arm 7 .
  • the timer 261 starts time measurement.
  • a case where the operating device 25 is operated by the operator so that the amount of operation M increases from 0 to value M 3 v will be considered.
  • the value M 3 v is larger than the lower limit value M 1 of the amount of operation generated by the limited amount of operation Mr, the value M 2 of the limited amount of operation, and the value M 3 of the largest amount of operation.
  • the amount of operation M maintains the value M 3 v for a certain period after reaching the value M 3 v.
  • the amount of operation M maintains the value M 3 v.
  • the time tg is the time occurring after the predetermined period Ts has elapsed from the start time t 0 .
  • the profile of the limited amount of operation Mr is indicated by line S 2 .
  • the limited amount of operation Mr indicated by the line S 2 is the same as the limited amount of operation Mr described with reference to FIG. 23 or the like. Detailed description of the limited amount of operation Mr indicated by the line S 2 will not be provided.
  • the limited amount of operation Mr indicated by the line S 2 has the value M 2 .
  • the limited amount of operation Mr is smaller than the value M 3 v of the amount of operation M. That is, in the example illustrated in FIG. 40 , in the period between the time t 0 and the time ta, the amount of operation M exceeds the limited amount of operation Mr indicated by the line S 2 .
  • the arm 7 is driven based on the limited amount of operation Mr.
  • the operating device 25 is operated so that the amount of operation M decreases. That is, in a state where the arm 7 is driven based on the limited amount of operation Mr, the operating device 25 may be operated abruptly so that the amount of operation M decreases abruptly at the time tg as indicated by the line S 1 of FIG. 40 and becomes smaller than the limited amount of operation Mr indicated by the line S 2 at the time ta.
  • the operating device 25 is operated abruptly and the amount of operation M decreases abruptly.
  • the amount of operation M decreases abruptly from the value M 3 v to the value M 1 v.
  • the value M 1 v of the amount of operation M is larger than the value M 1 and is smaller than the value M 2 of the limited amount of operation Mr.
  • the detection device 70 When the amount of operation M decreases (falls) abruptly, the change in the amount of operation M is detected by the detection device 70 (step SD 7 ).
  • the detection result of the detection device 70 is output to a determining unit 262 A of the limit value setting unit 262 .
  • the determining unit 262 A determines whether a decrease rate (the amount of decrease per unit time) of the amount of operation M exceeds an allowable value (step SD 8 ).
  • step SD 8 When it is determined in step SD 8 that the decrease rate is equal to or smaller than the allowable value (that is, No in step SD 8 ), the flow returns to step SD 4 and the work machine controller 26 compares the decreased amount of operation M with the limited amount of operation Mr and executes the above-described process.
  • step SD 8 When it is determined in step SD 8 that the decrease rate of the amount of operation M exceeds the allowable value (that is, Yes in step SD 8 ), the limit value setting unit 262 of the work machine controller 26 maintains the limited amount of operation Mr at the decrease start time tg to a certain value M 4 (step SD 9 ).
  • the limited amount of operation Mr is maintained to the value M 4 from the time tg as indicated by line S 2 a of FIG. 40 .
  • the arm 7 is driven based on the changed limit pattern S 2 a. In this way, it is possible to suppress the sense of incongruity that the operator might feel.
  • the arm control unit 263 compares the amount of operation M with the reset limited amount of operation Mr indicated by the line S 2 a (step SD 10 ).
  • step SD 10 When it is determined in step SD 10 that the amount of operation M is equal to or smaller than the limited amount of operation Mr (that is, No in step SD 10 ), the arm control unit 263 selects the amount of operation M and uses the same as the amount of operation Mf. The arm control unit 263 does not generate the control signal N. The arm 7 is driven with the pilot pressure adjusted based on the amount of operation M of the operating device 25 (step SD 11 ).
  • step SD 10 When it is determined in step SD 10 that the amount of operation M is larger than the limited amount of operation Mr (that is, Yes in step SD 10 ), the arm control unit 263 selects the limited amount of operation Mr and uses the same as the amount of operation Mf. The arm control unit 263 generates the control signal N based on the selected limited amount of operation Mr. In this way, the arm speed limitation control is performed based on the limited amount of operation Mr (step SD 12 ).
  • FIG. 41 illustrates an example of the reset limit pattern S 4 a.
  • FIG. 42 illustrates an example of the profile of the amount of operation Mf according to the present embodiment.
  • the profile of the amount of operation Mf is indicated by line Sc.
  • the arm 7 in the period Ts between the time t 0 and the time ta, the arm 7 is operated with the pilot pressure adjusted according to the limited amount of operation Mr as indicated by the line Sc.
  • the arm 7 In the period later than the time ta, the arm 7 is operated with the pilot pressure adjusted according to the amount of operation M.
  • the arm 7 is operated with the pilot pressure adjusted according to the limited amount of operation Mr.
  • the arm 7 when the arm 7 is driven based on the limit pattern S 2 , the arm 7 is moved so as to be accelerated, and the operating device 25 is operated so as to be decelerated, a portion of the limit pattern S 2 is changed to obtain the limit pattern S 2 a so that the limited amount of operation Mr is maintained to a certain value without being increased.
  • the limit pattern S 2 a so that the limited amount of operation Mr is maintained to a certain value without being increased.
  • FIG. 43 is a functional block diagram of the control system 200 according to the present embodiment. As illustrated in FIG. 43 , in the present embodiment, the work machine controller 26 has a distance determining unit 262 B.
  • FIG. 44 is a schematic view illustrating an example of the excavator 100 according to the present embodiment.
  • the excavator 100 includes the vehicle body 1 and the work machine 2 .
  • the vehicle body 1 supports the boom 6 .
  • the distance x between the reference position P 2 of the vehicle body 1 and the position P 3 of the cutting edge 8 a of the bucket 8 changes.
  • the distance x may be the distance between the position of the boom pin and the position of the cutting edge 8 a and may be the distance between the installed position P 1 and the cutting edge 8 a.
  • the distance x between the reference position P 2 and the position P 3 is calculated from the tilt angles ⁇ 1 to ⁇ 3 of the work machines output from the sensor controller 30 , and the limited amount of operation Mr when the work machine 2 is driven so that the distance x between the reference position P 2 and the position P 3 is a first distance is smaller than the limited amount of operation Mr when the work machine 2 is driven so that the distance x between the reference position P 2 and the position P 3 is a second distance shorter than the first distance.
  • FIG. 45 is a timing chart for describing an example of the operation of the control system 200 according to the present embodiment.
  • the horizontal axis is time and the vertical axis is the amount of operation M (limited amount of operation Mr) of the arm 7 and the count value of the timer.
  • FIG. 46 illustrates an example of the profile of the amount of operation Mf determined based on the limit pattern S 2 .
  • FIG. 47 illustrates an example of the profile of the amount of operation Mf determined based on the limit pattern S 5 .
  • the limited amount of operation Mr when the distance x is the first distance which is long is smaller than the limited amount of operation Mr when the distance x is the second distance which is short. That is, in the first distance state, the movement of the arm 7 is limited more strictly than in the second distance state. In this way, the occurrence of the following delay of the boom 6 is suppressed. Thus, a decrease in the excavation accuracy is suppressed.
  • the limited amount of operation Mr when the work machine 2 is driven so that the distance between the reference position of the vehicle body 1 and the bucket 8 is the first distance is smaller than the limited amount of operation Mr when the work machine 2 is driven so that the distance between the reference position of the vehicle body 1 and the bucket 8 is the second distance shorter than the first distance.
  • the operating device 25 is a pilot hydraulic-type operating device.
  • the operating device 25 may be an electric lever-type operating device.
  • an operating lever detecting unit that detects an amount of operation of the operating lever of the operating device 25 with the aid of a potentiometer or the like and outputs a detection value corresponding to the amount of operation to the work machine controller 26 may be provided.
  • the work machine controller 26 may output a control signal to the direction control valve 64 based on the detection result of the operating lever detecting unit to adjust the amount of operating oil supplied to the hydraulic cylinder.
  • the control according to the present invention may be performed by other controllers such as the sensor controller 30 as well as a work machine controller 226 .
  • the position of the excavator CM in the global coordinate system may be acquired by other position measurement means without being limited to GNSS.
  • the distance d between the designed landform and the cutting edge 8 a may be acquired by other position measurement means without being limited to GNSS.

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Operation Control Of Excavators (AREA)
US14/391,567 2014-06-02 2014-06-02 Construction machine control system, construction machine, and method of controlling construction machine Abandoned US20170121930A1 (en)

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10584463B2 (en) 2016-11-29 2020-03-10 Komatsu Ltd. Control device for construction machine and method of controlling construction machine
WO2021061321A1 (en) * 2019-09-27 2021-04-01 Topcon Positioning Systems, Inc. Method and apparatus for mitigating machine operator command delay
US11001989B1 (en) * 2020-03-30 2021-05-11 Caterpillar Inc. Electrical control of a hydraulic system
US20210293972A1 (en) * 2020-03-18 2021-09-23 Totalmasters Co., Ltd. Positioning calibration method for construction working machines and its positioning calibration controller
US11408449B2 (en) 2019-09-27 2022-08-09 Topcon Positioning Systems, Inc. Dithering hydraulic valves to mitigate static friction
US11585073B2 (en) 2016-06-21 2023-02-21 Komatsu Ltd. Construction system and construction method
US11591768B2 (en) 2017-08-31 2023-02-28 Komatsu Ltd. Control system of work machine and method for controlling work machine
US11808010B2 (en) 2019-10-01 2023-11-07 Caterpillar Underground Mining Pty. Ltd. Method and system for operating implement assemblies of machines
US11987949B2 (en) * 2017-08-30 2024-05-21 Topcon Positioning Systems, Inc. Method and apparatus for machine operator command attenuation

Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105899737B (zh) * 2013-12-26 2018-06-01 斗山英维高株式会社 工程机械的主控阀的控制方法及控制装置
US20160201298A1 (en) * 2015-01-08 2016-07-14 Caterpillar Inc. Systems and Methods for Constrained Dozing
EP3276088B1 (en) * 2015-03-27 2022-05-11 Sumitomo (S.H.I.) Construction Machinery Co., Ltd. Shovel
JP6619163B2 (ja) * 2015-06-17 2019-12-11 日立建機株式会社 作業機械
US9903100B2 (en) * 2015-07-02 2018-02-27 Caterpillar Inc. Excavation system providing automated tool linkage calibration
JP6532797B2 (ja) * 2015-10-08 2019-06-19 日立建機株式会社 建設機械
WO2017146291A1 (ko) * 2016-02-26 2017-08-31 김성훈 중장비 암의 위치 측정 방법 및 장치
WO2016125916A1 (ja) * 2016-03-17 2016-08-11 株式会社小松製作所 作業車両の制御システム、制御方法、及び作業車両
JP6506205B2 (ja) * 2016-03-31 2019-04-24 日立建機株式会社 建設機械
JP6495857B2 (ja) 2016-03-31 2019-04-03 日立建機株式会社 建設機械
JP6732539B2 (ja) * 2016-05-26 2020-07-29 日立建機株式会社 作業機械
JP6618852B2 (ja) * 2016-05-26 2019-12-11 日立建機株式会社 作業機械
SE542711C2 (en) * 2016-06-09 2020-06-30 Husqvarna Ab Improved arrangement and method for operating a hydraulically operated boom carrying a tool
CN108055855B (zh) * 2016-09-16 2020-11-10 日立建机株式会社 作业机械
KR102065478B1 (ko) * 2017-04-10 2020-01-13 가부시키가이샤 고마쓰 세이사쿠쇼 건설 기계 및 제어 방법
US10645855B2 (en) * 2017-06-28 2020-05-12 Cnh Industrial America Llc Lift arm control system
JP6901406B2 (ja) * 2017-07-14 2021-07-14 株式会社小松製作所 作業機械および作業機械の制御方法
JP6901336B2 (ja) 2017-07-14 2021-07-14 株式会社小松製作所 建設機械、較正システム、および方法
JP6807293B2 (ja) 2017-09-26 2021-01-06 日立建機株式会社 作業機械
JP6957081B2 (ja) * 2017-10-30 2021-11-02 日立建機株式会社 作業機械
CN110799708B (zh) * 2018-03-12 2021-12-31 日立建机株式会社 作业机械
EP3779053A4 (en) * 2018-03-30 2021-05-05 Sumitomo (S.H.I.) Construction Machinery Co., Ltd. EXCAVATOR
US10870968B2 (en) 2018-04-30 2020-12-22 Deere & Company Work vehicle control system providing coordinated control of actuators
JP7141899B2 (ja) * 2018-09-13 2022-09-26 日立建機株式会社 作業機械
JP2020133223A (ja) * 2019-02-19 2020-08-31 コベルコ建機株式会社 安全装置及び建設機械
JP7269411B2 (ja) * 2019-03-27 2023-05-08 日立建機株式会社 作業機械
KR102517099B1 (ko) * 2019-03-27 2023-04-04 히다찌 겐끼 가부시키가이샤 작업 기계
CN110258713B (zh) * 2019-06-26 2021-05-14 广西柳工机械股份有限公司 装载机工作装置位置参数数据的获取方法
JP7043470B2 (ja) * 2019-09-26 2022-03-29 日立建機株式会社 作業機械
CN110777861A (zh) * 2019-10-16 2020-02-11 南宁学院 一种装载机铲斗平移举升装置
KR102125664B1 (ko) * 2020-01-13 2020-06-22 이상룡 굴삭 레벨 검측 장치
JP7274671B2 (ja) * 2021-01-27 2023-05-16 日立建機株式会社 油圧ショベル
CN114592865A (zh) * 2022-02-25 2022-06-07 三一重型装备有限公司 掘进机的控制方法、装置、可读存储介质和掘进机
CN114688004B (zh) * 2022-03-16 2023-10-27 三一重机有限公司 流量分配方法、装置及作业机械

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3091667B2 (ja) * 1995-06-09 2000-09-25 日立建機株式会社 建設機械の領域制限掘削制御装置
JP3656776B2 (ja) * 1996-03-26 2005-06-08 株式会社小松製作所 油圧ショベルの油圧パイロット操作回路
JPH10195916A (ja) * 1997-01-13 1998-07-28 Hitachi Constr Mach Co Ltd 多関節建設機械の制御装置
US20020104431A1 (en) * 1999-09-09 2002-08-08 Sohel Anwar Method and apparatus for controlling the actuation of a hydraulic cylinder
JP4116369B2 (ja) * 2002-08-30 2008-07-09 株式会社小松製作所 ピン組立体及び作業機連結装置
DE60232553D1 (de) * 2002-09-26 2009-07-16 Hitachi Construction Machinery Antriebsaggregatsteuerung einer baumaschine.
JP3992644B2 (ja) * 2003-05-19 2007-10-17 ナブテスコ株式会社 バケット平行移動機能を有する多連方向切換弁
US7114747B2 (en) * 2003-10-20 2006-10-03 Cnh America Llc Work vehicle stabilizer
JP4455086B2 (ja) * 2004-02-09 2010-04-21 キャタピラージャパン株式会社 伸縮アームを有する作業機のアーム縮小動作制御装置
JP2006265954A (ja) 2005-03-24 2006-10-05 Hitachi Constr Mach Co Ltd 作業機械の目標作業面設定装置
EP2148958B1 (en) * 2007-05-18 2012-12-12 Volvo Construction Equipment AB A method for recuperating potential energy during a lowering operation of a load
JP5390888B2 (ja) * 2009-03-04 2014-01-15 株式会社小松製作所 建設機械の潤滑油量制御装置
KR101769485B1 (ko) * 2010-07-30 2017-08-30 볼보 컨스트럭션 이큅먼트 에이비 건설기계용 선회유량 제어시스템 및 그 제어방법
US9020709B2 (en) 2011-03-24 2015-04-28 Komatsu Ltd. Excavation control system
JP5548306B2 (ja) * 2011-03-24 2014-07-16 株式会社小松製作所 作業機制御システム、建設機械及び作業機制御方法
DE112012001013B4 (de) * 2011-03-24 2019-01-03 Komatsu Ltd. Aushubsteuersystem und Baumaschine
JP2012225084A (ja) 2011-04-21 2012-11-15 Kobelco Contstruction Machinery Ltd 建設機械
US9097341B2 (en) * 2012-01-26 2015-08-04 Caterpillar Inc. Brake system having a brake capacity test mode for a machine having a hydrostatic drivetrain
JP5597222B2 (ja) 2012-04-11 2014-10-01 株式会社小松製作所 油圧ショベルの掘削制御システム
US9080319B2 (en) * 2012-04-17 2015-07-14 Wyoming Machinery Company Inc. Systems and methods for attachment control signal modulation
US9411325B2 (en) 2012-10-19 2016-08-09 Komatsu Ltd. Excavation control system for hydraulic excavator
US9551131B2 (en) * 2014-12-10 2017-01-24 Caterpillar Inc. Power system having clutch-based fuel control modes

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11585073B2 (en) 2016-06-21 2023-02-21 Komatsu Ltd. Construction system and construction method
US10584463B2 (en) 2016-11-29 2020-03-10 Komatsu Ltd. Control device for construction machine and method of controlling construction machine
US11987949B2 (en) * 2017-08-30 2024-05-21 Topcon Positioning Systems, Inc. Method and apparatus for machine operator command attenuation
US11591768B2 (en) 2017-08-31 2023-02-28 Komatsu Ltd. Control system of work machine and method for controlling work machine
US11408449B2 (en) 2019-09-27 2022-08-09 Topcon Positioning Systems, Inc. Dithering hydraulic valves to mitigate static friction
CN114245836A (zh) * 2019-09-27 2022-03-25 拓普康定位系统公司 用于减轻机械操作员命令延迟的方法和装置
US20210095437A1 (en) * 2019-09-27 2021-04-01 Topcon Positioning Systems, Inc. Method and apparatus for mitigating machine operator command delay
US11828040B2 (en) * 2019-09-27 2023-11-28 Topcon Positioning Systems, Inc. Method and apparatus for mitigating machine operator command delay
WO2021061321A1 (en) * 2019-09-27 2021-04-01 Topcon Positioning Systems, Inc. Method and apparatus for mitigating machine operator command delay
US11808010B2 (en) 2019-10-01 2023-11-07 Caterpillar Underground Mining Pty. Ltd. Method and system for operating implement assemblies of machines
US20210293972A1 (en) * 2020-03-18 2021-09-23 Totalmasters Co., Ltd. Positioning calibration method for construction working machines and its positioning calibration controller
US11747483B2 (en) * 2020-03-18 2023-09-05 Totalmasters Co. Ltd Positioning calibration method for construction working machines and its positioning calibration controller
US11473271B2 (en) 2020-03-30 2022-10-18 Caterpillar Inc. Electrical control of a hydraulic system
US11001989B1 (en) * 2020-03-30 2021-05-11 Caterpillar Inc. Electrical control of a hydraulic system

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KR101791395B1 (ko) 2017-10-27
US20160040398A1 (en) 2016-02-11
JP6014260B2 (ja) 2016-10-25
DE112015000043T5 (de) 2015-12-03
DE112015000043B4 (de) 2019-02-28
WO2015137528A1 (ja) 2015-09-17
CN105324540A (zh) 2016-02-10
KR20150139541A (ko) 2015-12-11
JPWO2015137528A1 (ja) 2017-04-06
CN105324540B (zh) 2017-12-01

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