WO2020045018A1 - Blade control device for work machinery - Google Patents

Blade control device for work machinery Download PDF

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Publication number
WO2020045018A1
WO2020045018A1 PCT/JP2019/031265 JP2019031265W WO2020045018A1 WO 2020045018 A1 WO2020045018 A1 WO 2020045018A1 JP 2019031265 W JP2019031265 W JP 2019031265W WO 2020045018 A1 WO2020045018 A1 WO 2020045018A1
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WO
WIPO (PCT)
Prior art keywords
blade
load
target
threshold
load threshold
Prior art date
Application number
PCT/JP2019/031265
Other languages
French (fr)
Japanese (ja)
Inventor
俊明 沢村
前川　智史
菅野　直紀
大輔 野田
佑介 上村
Original Assignee
株式会社神戸製鋼所
コベルコ建機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社神戸製鋼所, コベルコ建機株式会社 filed Critical 株式会社神戸製鋼所
Priority to CN201980055037.5A priority Critical patent/CN112567098A/en
Priority to EP19855394.3A priority patent/EP3828347A1/en
Priority to US17/270,958 priority patent/US20210324604A1/en
Publication of WO2020045018A1 publication Critical patent/WO2020045018A1/en

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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
    • E02F3/76—Graders, bulldozers, or the like with scraper plates or ploughshare-like elements; Levelling scarifying devices
    • E02F3/7609—Scraper blade mounted forwardly of the tractor on a pair of pivoting arms which are linked to the sides of the tractor, e.g. bulldozers
    • E02F3/7618—Scraper blade mounted forwardly of the tractor on a pair of pivoting arms which are linked to the sides of the tractor, e.g. bulldozers with the scraper blade adjustable relative to the pivoting arms about a horizontal axis
    • 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
    • E02F3/76—Graders, bulldozers, or the like with scraper plates or ploughshare-like elements; Levelling scarifying devices
    • E02F3/80—Component parts
    • E02F3/84—Drives or control devices therefor, e.g. hydraulic drive systems
    • E02F3/844—Drives or control devices therefor, e.g. hydraulic drive systems for positioning the blade, e.g. hydraulically
    • 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
    • E02F3/96—Dredgers; Soil-shifting machines mechanically-driven with arrangements for alternate or simultaneous use of different digging elements
    • E02F3/963—Arrangements on backhoes for alternate use of different tools
    • E02F3/964—Arrangements on backhoes for alternate use of different tools of several tools mounted on one machine
    • 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 blade control device provided in a work machine having a blade.
  • Patent Literature 1 discloses a bulldozer load control device that automatically controls the raising and lowering operations of a blade so that the blade load applied to the blade becomes substantially constant.
  • the undulation of the construction surface caused by moving the blade up and down becomes a problem.
  • Patent Document 2 discloses a blade control device for addressing the above-described problem of Patent Document 1.
  • Patent Document 2 discloses that the blade is controlled so that the blade does not approach the design surface more than the virtual design surface, and that the blade can be prevented from descending greatly, whereby a continuous swell is formed on the excavation surface. It is disclosed that this can be suppressed.
  • the blade control device described in Patent Literature 2 when the blade load is smaller than the first set load value, the blade is lowered, and the blade load is changed from the second set load value larger than the first set load value. Raise the blade if too big. That is, in the blade control device described in Patent Literature 2, the raising / lowering operation of the blade is controlled based on a comparison between the blade load and the first set load value and the second set load value.
  • the present invention provides a blade control device provided in a work machine equipped with a blade for controlling the raising and lowering operation of the blade, wherein the blade control device can effectively suppress undulation of a construction surface.
  • the purpose is to:
  • a blade control device provided on a work machine including a machine main body and a blade attached to the machine main body so as to be able to move up and down, and controlling a raising and lowering operation of the blade,
  • a target design surface setting unit that sets a target design surface that specifies a target shape to be excavated by the blade
  • a position information acquisition unit that acquires position information about the work machine, and the position information that is acquired by the position information acquisition unit.
  • a blade position calculating unit that calculates a blade position that is the position of the blade in a global coordinate system, a blade load obtaining unit that obtains a blade load that is a load applied to the blade, and a threshold value of the blade load.
  • a first load threshold and a second load threshold that is a threshold of the blade load and is larger than the first load threshold.
  • a target position of the blade position, a target position setting unit that sets a blade target position that is a position above the target design surface, the blade load acquired by the blade load acquisition unit is In the case of being equal to or less than the second load threshold, a command for raising and lowering the blade is issued so that a position deviation, which is a deviation between the blade position and the blade target position calculated by the blade position calculator, approaches zero.
  • a blade operation control unit that outputs a command to raise the blade, comprising: The position setting unit associates the blade load with the first load threshold, and when an update condition set in advance is satisfied, the update is performed. Based on the said blade position when matter is met to update the blade target position.
  • FIG. 1 is a side view illustrating a hydraulic excavator as an example of a work machine on which a blade control device according to an embodiment of the present invention is mounted.
  • FIG. 3 is a block diagram illustrating main functions of the blade control device.
  • 5 is a graph showing a relationship between a blade position, a blade target position, and a blade elevating operation in the blade control device.
  • 4 is a graph showing a relationship among a blade load, a first load threshold, a second load threshold, and a blade elevating operation in the blade control device.
  • 4 is a flowchart illustrating an example of a control operation executed by a controller included in the blade control device.
  • FIG. 4 is a graph showing a target locus (target trajectory) of a blade load and a transition of an actual blade load in the blade control device.
  • 5 is an example of a time chart for explaining a blade target position updated based on a blade load in the blade control device.
  • 9 is another example of a time chart for explaining a blade target position updated based on a blade load in the blade control device.
  • FIG. 7 is a schematic diagram for explaining updating of a first load threshold based on a distance between a vehicle body position of a machine main body and a target design surface in the blade control device.
  • 6 is a graph for explaining updating of a first load threshold based on a distance between a vehicle body position of a machine body and a target design surface in the blade control device.
  • 9 is a graph for explaining that the blade control device updates a position gain based on a deviation between a blade position and a blade target position.
  • 9 is a graph for explaining that the blade controller updates a load gain based on a deviation between a blade load and a second load threshold. It is the schematic which compared the construction surface by the working machine provided with the said blade control apparatus, and the construction surface by the conventional working machine.
  • FIG. 1 is a side view showing a hydraulic excavator 1 as an example of a work machine on which a blade control device according to an embodiment of the present invention is mounted.
  • the hydraulic excavator 1 includes a traveling device 2 (a lower traveling body) that can travel on the ground G, a vehicle body 3 (an upper revolving superstructure) mounted on the traveling device 2, and a working device mounted on the vehicle body 3. And a blade 4 mounted on the traveling device 2 or the vehicle body 3.
  • the traveling device 2 and the vehicle body 3 constitute a machine body of the work machine.
  • the vehicle body 3 has a turning frame, an engine, a cab, and the like.
  • the working device mounted on the vehicle body 3 includes a boom 5, an arm 6, and a bucket 7.
  • the boom 5 has a base end supported at the front end of the revolving frame so as to be able to undulate, that is, rotatable around a horizontal axis, and a tip end on the opposite side.
  • the arm 6 has a base end that is rotatably mounted on the front end of the boom 5 about a horizontal axis, and a front end opposite to the base end.
  • the bucket 7 is rotatably attached to the tip of the arm 6.
  • the hydraulic excavator 1 has a boom cylinder, an arm cylinder, and a bucket cylinder provided for each of the boom 5, the arm 6, and the bucket 7.
  • the boom cylinder is interposed between the vehicle body 3 and the boom 5, and extends and contracts so as to cause the boom 5 to perform an up-and-down operation.
  • the arm cylinder is interposed between the boom 5 and the arm 6, and expands and contracts so as to cause the arm 6 to perform a rotating operation.
  • the bucket cylinder is interposed between the arm 6 and the bucket 7, and expands and contracts so as to cause the bucket 7 to perform a rotating operation.
  • the blade 4 mounted on the traveling device 2 or the vehicle body 3 is provided for performing operations such as excavation of the ground, leveling, and transportation of earth and sand.
  • the blade 4 is supported by a lift frame 4a, and the lift frame 4a is supported rotatably about the horizontal axis 4b with respect to the traveling device 2. Therefore, the blade 4 can be displaced vertically with respect to the traveling device 2.
  • the excavator 1 has a lift cylinder 8 provided for the blade 4.
  • the lift cylinder 8 has a head-side chamber 8h and a rod-side chamber 8r (see FIG. 1).
  • the lift cylinder 8 When hydraulic oil is supplied to the head-side chamber 8h, the lift cylinder 8 extends to move the blade 4 in a lowering direction and to move the rod-side chamber 8r. While the hydraulic oil in the inside is discharged, the hydraulic oil is supplied to the rod side chamber 8r to contract and move the blade 4 in the upward direction, and to discharge the hydraulic oil in the head side chamber 8h.
  • the hydraulic excavator 1 has a hydraulic circuit (not shown).
  • the hydraulic circuit includes the boom cylinder, the arm cylinder, the bucket cylinder, and the lift cylinder 8.
  • the hydraulic circuit further includes a hydraulic pump 9 (see FIG. 1), a lift cylinder control proportional valve 41 (see FIG. 2), and a lift cylinder flow control valve (not shown).
  • FIG. 2 is a block diagram illustrating main functions of the blade control device 100.
  • the blade control device 100 is provided to control the elevating operation of the blade 4.
  • the blade control device 100 includes a controller 10 (mechatronic controller), a position information acquisition unit, a blade load acquisition unit 34, an automatic control switch 35, and a traveling lever 36 for operating the traveling device 2.
  • the controller 10 includes, for example, a microcomputer and controls the operation of each element included in the hydraulic circuit.
  • the position information acquisition unit has a function of acquiring position information on the excavator 1.
  • the position information acquisition unit includes a vehicle body position acquisition unit 31, a vehicle body angle acquisition unit 32, and a blade angle acquisition unit 33.
  • the vehicle body position acquisition unit 31 has a function of acquiring a vehicle body position that is the position of the machine body.
  • the vehicle body position acquisition unit 31 is configured by a receiver capable of receiving satellite data (positioning signal) from a satellite positioning system, such as a receiver (GNSS sensor) of GNSS (Global Navigation Satellite System), and is a machine in a global coordinate system.
  • GNSS data indicating the position of the main body is received.
  • the global coordinate system is a three-dimensional coordinate system based on an origin defined on the earth, and is a coordinate system indicating an absolute position defined by the satellite positioning system.
  • the vehicle body angle acquisition unit 32 has a function of acquiring the angle of the machine body.
  • the vehicle body angle acquisition unit 32 is configured by, for example, a vehicle body angle sensor that detects the angle of the machine main body in the global coordinate system (in the present embodiment, the angle of the vehicle body 3).
  • the vehicle body angle sensor may be provided, for example, in the body of the aircraft, and may include one or a plurality of receivers capable of receiving satellite data (positioning signal) from a satellite positioning system.
  • the blade angle acquisition unit 33 has a function of acquiring the angle of the blade 4.
  • the blade angle acquisition unit 33 is configured by, for example, a blade angle sensor that detects the angle of the blade 4 in the global coordinate system.
  • the blade angle sensor may be provided in, for example, the body of the aircraft, and may be configured by one or a plurality of receivers capable of receiving satellite data (positioning signal) from a satellite positioning system.
  • the vehicle body angle sensor may be configured by, for example, an inertial measurement device, or may be configured by the inertial measurement device and the receiver that can receive the satellite data.
  • the inertial measurement device measures, for example, the acceleration and angular velocity of the vehicle body 3, and based on the measurement result, tilts the vehicle body 3 (for example, pitch indicating rotation about the X axis, yaw indicating rotation about the Y axis, and rotation about the Z axis). May be configured to be detectable.
  • the blade angle sensor may be configured by, for example, a stroke sensor that detects a cylinder stroke of the blade cylinder 8, or may be configured by the stroke sensor and the receiver that can receive the satellite data.
  • the vehicle body position obtaining unit 31 and the vehicle body angle obtaining unit 32 are mounted on the upper part of the vehicle body 3, and the blade angle obtaining unit 33 is mounted on the upper part of the blade 4.
  • Detection signals which are electric signals generated by the acquisition units 31, 32, and 33, are input to the controller 10.
  • the blade load obtaining unit 34 has a function of obtaining a blade load that is a load applied to the blade 4 during excavation work.
  • the blade load corresponds to, for example, the pump pressure of the hydraulic pump 9 that drives the blade 4. Therefore, the blade load acquisition unit 34 can detect the blade load by detecting the pump pressure.
  • the blade load acquisition unit 34 includes a head pressure sensor 34H that detects a head pressure P1 that is a pressure of hydraulic oil in the head-side chamber 8h of the lift cylinder 8, and a hydraulic pressure in the rod-side chamber 8r of the lift cylinder 8. And a rod pressure sensor 34R for detecting a rod pressure P2 as a pressure.
  • Each of the sensors 34H and 34R converts the detected physical quantity into a detection signal, which is an electric signal corresponding to the detected physical quantity, and inputs the detection signal to the controller 10.
  • the automatic control switch 35 is arranged in the cab and is electrically connected to the controller 10.
  • the automatic control switch 35 receives an operation for switching the control mode of the controller 10 from the manual operation mode to the automatic control mode, and inputs a mode command signal relating to the operation to the controller 10.
  • the controller 10 switches the setting of the control mode from the manual operation mode to the automatic control mode according to a mode command signal input from the automatic control switch 35.
  • the controller 10 is configured to automatically control the operation of the lift cylinder 8 so that the construction surface constructed by the blade 4 approaches a preset target design surface.
  • a command value (command current) to the lift cylinder control proportional valve 41 for controlling the operation of the lift cylinder 8 is output from the controller 10, the secondary pressure of the proportional valve 41 is increased according to the command value.
  • the opening degree of the lift cylinder flow control valve changes according to the secondary pressure.
  • the controller 10 includes a target design surface setting unit 11, a blade position calculation unit 12, a storage unit 13, a target position setting unit 14, a blade operation control unit 15, as functions for executing the automatic control. It has a load threshold setting unit 16, a position gain setting unit 17, a load gain setting unit 18, and a distance calculation unit 19.
  • the target design surface setting unit 11 sets a target design surface (see FIG. 9) for specifying a target shape to be excavated by the blade 4.
  • the target design surface setting unit 11 may store a design surface input by a target design surface input unit provided in the cab, and may set the design surface as a target design surface. Further, the target design surface setting unit 11 may store design surface data acquired via various storage media, a communication network, or the like, and set the design surface as a target design surface.
  • the target design plane setting unit 11 inputs the set target design plane to the target position setting unit 14.
  • the target design surface is a surface for specifying a three-dimensional design terrain, which is a target shape of the ground to be excavated.
  • the target design surface may be specified by external data such as BIM or CIM (Building / Construction / Information / Modeling, Management), or may be set based on the position of the work machine.
  • the blade position calculation unit 12 calculates a blade position x, which is a position of the blade 4 in a global coordinate system, based on the position information acquired by the position information acquisition unit.
  • the blade position calculating unit 12 obtains the vehicle body position obtained by the vehicle body position obtaining unit 31, the angle of the machine body obtained by the vehicle body angle obtaining unit 32, and the blade position obtaining unit 33.
  • the blade position x is calculated based on the angle of the blade 4. That is, the blade position x is calculated from the sum of a vector from the reference point to the vehicle body position and a vector from the vehicle body position to the blade position.
  • the blade position x is calculated based on the relative angle between the angle of the machine body and the angle of the blade 4 in the global coordinate system, but the method of calculating the blade position x is not limited to this.
  • the blade position x may be calculated based on, for example, the length of the lift cylinder 8, or a GNSS receiver (GNSS sensor) may be attached to the blade 4 and calculated based on GNSS data received by the GNSS sensor. .
  • GNSS sensor GNSS receiver
  • the blade position x is set at the cutting edge position, which is the tip of the blade 4 (the position of the lower edge of the tip of the blade 4), but may be set at another part of the blade 4. .
  • the storage unit 13 stores a first load threshold value f1 that is a threshold value of the blade load f and a second load threshold value f2 that is a threshold value of the blade load f and is larger than the first load threshold value f1.
  • the first load threshold f1 is set to a value corresponding to an appropriate blade load f at which the excavator 1 can run stably.
  • the second load threshold value f2 is a value set in order to prevent the occurrence of a situation in which the blade load f becomes excessive and a stack or the like occurs. That is, the second load threshold f2 is a value set to realize a stable and efficient excavation operation.
  • These load thresholds f1 and f2 may be manually input to the controller 10 by the operator before the excavation work, or may be appropriately calculated and stored by the controller 10 during the excavation work.
  • the storage unit 13 stores a preset update condition.
  • the update condition is a condition that is set in advance by associating the blade load f with the first load threshold, and is a criterion for determining whether or not the target position setting unit 14 updates the blade target position xref. It becomes.
  • the update condition includes the condition that the blade load f approaches the first load threshold value f1 and these deviations become sufficiently small.
  • the update condition is a condition that the blade load f reaches the first load threshold value f1 or the second condition in order to determine that the blade load f approaches the first load threshold value f1. It includes a condition that the blade load f reaches a determination value set based on one load threshold f1.
  • the determination value is a value that can determine that the deviation (f ⁇ f1) obtained by subtracting the first load threshold f1 from the blade load f is sufficiently small.
  • the determination value is a threshold value set in advance through a simulation, an experiment, or the like.
  • the storage unit 13 stores a target trajectory (see FIG. 6 described later).
  • the target trajectory is a target of an increasing process of the blade load f when the blade load f approaches the first load threshold f1 while increasing.
  • the target trajectory is set such that the blade load f follows a preferred increase process up to the first load threshold f1 when the blade target position xref is not set at the start of the excavation operation in which the automatic control mode is selected. This is set in advance to control the elevating operation of the blade 4.
  • the target position setting unit 14 sets a target blade position xref, which is a target position of the blade position x and a position above the target design surface.
  • the target position setting unit 14 sets the blade target position xref based on, for example, the blade load f and the blade position x.
  • the load threshold setting unit 16 sets the first load threshold f1.
  • the position gain setting unit 17 sets the position gain kx.
  • the load gain setting unit 18 sets the load gain kf. The details of the load threshold setting unit 16, the position gain setting unit 17, and the load gain setting unit 18 will be described later.
  • the blade operation control unit 15 calculates and outputs a command value to the lift cylinder control proportional valve 41 for controlling the operation of the lift cylinder 8. Specifically, it is as follows.
  • FIG. 3 is a graph showing the relationship between the blade position x, the blade target position xref, and the lifting / lowering operation of the blade 4 in the blade control device 100.
  • the blade operation control unit 15 is for raising and lowering the blade 4 so that a position deviation ⁇ x, which is a deviation between the blade position x calculated by the blade position calculation unit 12 and the blade target position xref, approaches zero.
  • the command (command value) is calculated and output.
  • the control of the blade position x is feedback control that changes the control amount in accordance with the magnitude of the position deviation ⁇ x, which is the deviation between the blade position x and the blade target position xref.
  • the blade operation control unit 15 includes, as a variable, a position deviation ⁇ x which is a height difference between the blade position x and the blade target position xref, and a term including a position gain kx by which the position deviation ⁇ x is multiplied.
  • the command is calculated and output based on the function of the command.
  • the blade target position xref is located at a position corresponding to the origin on the horizontal axis of the graph, and is provided with a hysteresis for suppressing hunting.
  • the blade operation control unit 15 Does not control the position x.
  • FIG. 4 is a graph showing the relationship among the blade load f, the first load threshold f1, the second load threshold f2, and the lifting / lowering operation of the blade 4 in the blade control device 100.
  • the blade operation control unit 15 raises the blade 4.
  • the command (command value) is calculated and output.
  • the blade operation control unit 15 includes, as a variable, a load deviation ⁇ f which is a deviation (ff ⁇ 2) obtained by subtracting the second load threshold value f2 from the blade load f, for example.
  • the command is calculated and output based on a function having a term including the load gain kf multiplied by the deviation ⁇ f.
  • the position control of the blade 4 as shown in FIG. 3 has priority.
  • the blade load f becomes larger than the second load threshold value f2
  • the blade position is controlled so that the blade 4 moves up quickly.
  • the controller 10 determines whether or not the automatic control switch 35 is turned on, that is, whether or not the automatic control mode is selected (Step S1). If the automatic control mode is not selected (NO in step S1), the controller 10 ends the process without performing the control in the automatic control mode.
  • the controller 10 captures a signal input to the controller 10, specifically, a detection signal or a designation signal of each sensor (step S2). .
  • the designation signal includes a signal about a target design surface designated by an operation of an input unit of the target design surface by the operator, a signal about a blade load f acquired by the blade load acquisition unit 34, and a signal about the vehicle body position acquisition unit 31.
  • the signal about the acquired vehicle body position, the signal about the angle of the machine main body acquired by the vehicle body angle acquisition unit 32, the signal about the angle of the blade 4 acquired by the blade angle acquisition unit 33, and the traveling lever 36 A signal about the traveling speed corresponding to the operation to be received is included.
  • the controller 10 acquires the initial state of the excavator 1. Further, the target design surface setting unit 11 of the controller 10 sets a target design surface based on the signal for the target design surface.
  • the controller 10 determines whether or not the blade target position xref has been set (Step S3). If the blade target position xref has not been set (NO in step S3), the blade operation control unit 15 causes the blade load f to approach the first load threshold f1 while following an increasing process close to the target trajectory. Then, a command for raising and lowering the blade 4 is output (step S4).
  • the setting of the target trajectory is not essential in the blade control device of the present invention, the target trajectory is set as in the present embodiment, and the blade position x is controlled based on the target trajectory.
  • FIG. 6 is a graph showing a target trajectory (target trajectory) of the blade load f and a transition of the actual blade load f in the blade control device 100.
  • a curve shown by a dashed line is the target trajectory (target trajectory)
  • a curve shown by a solid line is a transition of the actual blade load f.
  • the blade load f follows an increasing process close to the target trajectory. While approaching the first load threshold f1, the blade 4 enters the ground at an appropriate descent speed, and the blade 4 enters the ground at a depth when the blade load f reaches the first load threshold f1.
  • the increase can be suppressed.
  • the change in the amount of soil on the blade 4 with respect to the travel distance of the excavator 1 is small, and the fluctuation of the blade load f is also small. As a result, the effect of suppressing undulation on the construction surface can be further enhanced.
  • the target trajectory may be any as long as the blade load f can be controlled so that the blade load f gradually approaches the first load threshold f1 as described above. Is not particularly limited.
  • the target trajectory (target trajectory) may be given, for example, by a function representing a curved trajectory such that the blade load f gradually approaches the first load threshold f1 as shown by a chain line in FIG.
  • the target trajectory (target trajectory) may be given by a function (linear function) representing a straight trajectory, or may be given by a function representing a combination of a curved trajectory and a straight trajectory.
  • the target position setting section 14 sets the blade target position xref.
  • the condition is that the blade load f reaches the first load threshold value f1, and more specifically, the load deviation, which is the deviation (f ⁇ f1), changes from a negative value to a positive value.
  • the blade target position xref set by the target position setting unit 14 is set to a position on a plane parallel to the target design plane, passing through the blade position x when the condition is satisfied. You. After the target blade position xref is set, the blade operation control unit 15 controls the raising / lowering operation of the blade 4 so that the positional deviation ⁇ x between the blade position x and the target blade position xref approaches zero.
  • the controller 10 compares the blade load f acquired by the blade load acquisition unit 34 with a flag threshold which is a preset threshold (Step S5).
  • the flag threshold is the same as the second load threshold f2, but is not limited thereto, and may be different from the second load threshold f2. However, the flag threshold is set to a value larger than the first load threshold f1.
  • the storage unit 13 When the blade load f is larger than the second load threshold f2 (flag threshold) (f> f2, NO in step S5), the storage unit 13 indicates that the update of the blade target position xref is permitted.
  • the blade load f is equal to or less than the second load threshold f2 (flag threshold) (f ⁇ f2, YES in step S5), the storage of the update flag is not changed.
  • the target position setting unit 14 updates the blade target position xref (step S8).
  • the blade target position xref updated by the target position setting unit 14 is set to a position on a plane that passes through the blade position x and is parallel to the target design plane when the update condition is satisfied. Is done.
  • FIG. 7 is an example of a time chart for describing the blade target position xref updated in the blade control device 100 based on the blade load f.
  • the second condition and the third condition among the update conditions are satisfied.
  • the condition has not been met. Therefore, at times t1 and t2, the update condition is not satisfied (NO in step S7), so that the target position setting unit 14 does not update the blade target position xref.
  • the target position setting unit 14 updates the blade target position xref.
  • the update of the blade target position xref is not limited to the mode shown in FIG.
  • FIG. 8 is another example of a time chart for explaining the blade target position xref updated based on the blade load f.
  • the update condition does not include the first condition, but includes the second condition and the third condition among the first condition, the second condition, and the third condition.
  • the target position setting unit 14 updates the blade target position xref at times when the update condition is satisfied, that is, at times t1, t2, and t4 when the second condition and the third condition are satisfied. I do.
  • the blade operation control unit 15 calculates a command value to the lift cylinder control proportional valve 41 for controlling the operation of the lift cylinder 8 (Step S9).
  • the blade operation control unit 15 determines whether the command value is equal to or less than a preset upper limit value (Step S10). If the command value is equal to or less than the preset upper limit value (YES in step S10), blade operation control section 15 outputs the command value, and the output command value is output to proportional valve 41 (FIG. 2). ), And the control is applied (step S12).
  • the blade operation control unit 15 sets the value cut off to the upper limit value as a command value (step S11). The command value that has been cut off is output, and the output command value is input to the proportional valve 41 (see FIG. 2), and the control is applied (step S12).
  • the command value calculated by the blade operation control unit 15 in step S9 is calculated based on, for example, a function represented by the following equation (1).
  • Command value kx ( ⁇ x) ⁇ ⁇ x + kf ( ⁇ f) ⁇ ⁇ f (1)
  • the function represented by the above equation (1) includes, as a variable, a position deviation ⁇ x that is a height difference between the blade position x and the blade target position xref, and a position gain kx multiplied by the position deviation ⁇ x.
  • FIG. 9 is a schematic diagram for explaining updating the first load threshold value f1 based on the distance between the vehicle body position of the machine main body and the target design surface in the blade control device 100.
  • FIG. It is a graph for explanation.
  • the load threshold setting unit 16 determines that the main body distance Z, which is the distance between the vehicle body position acquired by the vehicle body position acquisition unit 31 and the target design plane, is a first distance Z1.
  • the first load threshold f1 is updated so that the first load threshold f1 is smaller than when there is a certain distance. Is configured.
  • the distance calculation unit 19 calculates the main body distance Z based on the target design surface and the vehicle body position.
  • the main body distance Z is the second distance Z2 (that is, when the machine main body is close to the target design surface)
  • the main body distance Z is equal to the first distance Z1.
  • the blade load f is more likely to reach the first load threshold f1 than in a certain case (that is, when the machine body is far from the target design surface).
  • the distance ⁇ Z2 between the vehicle body position in the former case and the blade target position xref is equal to the vehicle body position and the blade target position xref in the latter case. Is smaller than the distance ⁇ Z1.
  • the frequency of updating the blade target position xref is increased, and the possibility that the blade target position xref is set to a more appropriate position corresponding to the state of the ground to be excavated is increased.
  • the first load threshold f1 when the ground leveling operation is performed in the final stage of the operation by the excavator 1 is larger than the first load threshold f1 when the excavation operation is performed in the initial stage or the intermediate stage of the operation.
  • the same control algorithm can be used for both the excavation operation where quick excavation work is more important than the leveling operation and the leveling operation where emphasis is placed on the accuracy of bringing the construction surface closer to the target design surface. become.
  • the load threshold value setting unit 16 sets the load threshold value in a part of the entire range of the main body distance Z including the first distance Z1 and the second distance Z2.
  • the first load threshold f1 is updated so that the first load threshold f1 decreases as the body distance Z decreases.
  • the load threshold setting unit 16 does not update the first load threshold f1 in a range where the body distance Z is larger than the partial range and in a range where the body distance Z is smaller than the partial range.
  • the update of the first load threshold f1 is not limited to the specific example shown in FIG.
  • FIG. 11 is a graph for explaining that the blade control device 100 updates the position gain kx based on the position deviation ⁇ x which is the deviation (x ⁇ xref) between the blade position x and the blade target position xref. .
  • the position gain setting unit 17 sets the position gain ⁇ such that the rising speed of the blade 4 is increased based on the position deviation ⁇ x. Update the position gain kx.
  • the rising speed of the blade 4 is increased, so that the ground to be excavated is prevented from being excavated below the blade target position xref. As a result, the effect of suppressing the ground from being excavated below the target design surface is further increased.
  • FIG. 12 is a graph for explaining that the blade controller 100 updates the load gain kf based on the deviation ⁇ f between the blade load f and the second load threshold f2.
  • the load gain setting unit 18 controls the load so that the rising speed of the blade 4 is increased based on the load deviation ⁇ f. Update the gain kf.
  • the rising speed of the blade 4 is increased, so that the blade load f is reduced more quickly, a stack or the like due to an excessive load is prevented, and the hydraulic excavator is prevented. 1, the effect of enabling stable running is further enhanced.
  • the undulating surface of the hydraulic shovel 1 including the blade control device 100 according to the present embodiment has an undulation as compared with the conventional hydraulic shovel 1. Effectively suppressed.
  • the present invention is not limited to the embodiment described above.
  • the present invention includes the following embodiments, for example.
  • the work machine to which the blade control device according to the present invention is applied is not limited to a hydraulic shovel.
  • the present invention can be widely applied to other work machines including a blade, such as a wheel loader, a bulldozer, and a grader.
  • a blade control device capable of effectively suppressing undulation on a construction surface.
  • a blade control device provided on a work machine including a machine main body and a blade attached to the machine main body so as to be able to move up and down, and controlling a raising and lowering operation of the blade,
  • a target design surface setting unit that sets a target design surface that specifies a target shape to be excavated by the blade
  • a position information acquisition unit that acquires position information about the work machine, and the position information that is acquired by the position information acquisition unit.
  • a blade position calculating unit that calculates a blade position that is the position of the blade in a global coordinate system, a blade load obtaining unit that obtains a blade load that is a load applied to the blade, and a threshold value of the blade load.
  • a first load threshold and a second load threshold that is a threshold of the blade load and is larger than the first load threshold.
  • a target position of the blade position, a target position setting unit that sets a blade target position that is a position above the target design surface, the blade load acquired by the blade load acquisition unit is In the case of being equal to or less than the second load threshold, a command for raising and lowering the blade is issued so that a position deviation, which is a deviation between the blade position and the blade target position calculated by the blade position calculator, approaches zero.
  • a blade operation control unit that outputs a command to raise the blade, comprising: The position setting unit associates the blade load with the first load threshold, and when an update condition set in advance is satisfied, the update is performed. Based on the said blade position when matter is met to update the blade target position.
  • the blade control device When the blade load is larger than the second load threshold, the blade control device performs control to raise the blade, thereby preventing a stack or the like due to an excessive load, thereby enabling a stable traveling of the work machine. I do.
  • the controller controls the raising / lowering operation of the blade such that the positional deviation between the blade position and the blade target position approaches zero. In this manner, even when the blade load is equal to or less than the second load threshold, performing position control of the blade so that the position deviation approaches zero, the blade load is controlled to the second set load value as in Patent Document 2 described above.
  • the first load threshold is set to a value corresponding to an appropriate blade load at which the work machine can run stably.
  • the update condition is set in advance by associating the actual blade load that fluctuates during the excavation work with the first load threshold value that is a value corresponding to an appropriate blade load. Since the blade target position is updated based on the blade position when the update condition is satisfied, the blade target position is associated with the blade position when the blade load is appropriate. Therefore, by repeatedly updating the blade target position in the excavation work, the blade load during the excavation work is easily stabilized regardless of the state of the ground to be excavated (for example, the hardness of the earth and sand, the type of earth and sand, etc.). Become.
  • the second load threshold is a value set in order to prevent a situation in which a blade load becomes excessive and a stack or the like occurs
  • the first load threshold is set. It is a value larger than.
  • control for raising the blade is performed. This reduces the blade load as described above, and prevents a stack or the like due to an excessive load from occurring, thereby enabling stable running of the work machine.
  • the blade control device can effectively suppress the undulation of the construction surface, and also enables the work machine to perform a stable and efficient excavation operation.
  • the update condition may include a condition that the blade load reaches the first load threshold, or the first load threshold for determining that the blade load has approached the first load threshold. It is preferable to include a condition that the blade load reaches a determination value set based on the blade load.
  • the blade target position is updated based on the blade position when the blade load has reached or approached the first load threshold, so that the blade target position substantially matches the blade position when the blade load is appropriate. It will be. Therefore, the blade load during the excavation work is more easily stabilized.
  • the storage unit stores a first state indicating that the update of the blade target position is permitted when the blade load becomes larger than a flag threshold value that is a preset threshold value,
  • a second state indicating that the update of the blade target position is not permitted is stored in place of the first state
  • the update condition is that the first state is the storage state.
  • the condition that the blade load reaches the first load threshold when stored in the storage unit, or the condition that the blade load reaches the first load threshold when the first state is stored in the storage unit.
  • the blade target position updated by the target position setting unit is set to a position on a plane passing through the blade position when the update condition is satisfied and parallel to the target design plane.
  • the lifting / lowering operation of the blade is controlled such that the positional deviation between the blade target position and the blade position set at a position on a plane parallel to the target design surface approaches zero. The efficiency of the excavation work to bring the distance closer to the target design surface is further improved.
  • the storage unit stores a target trajectory that is a target of the blade load increase process when the blade load approaches the first load threshold while increasing
  • the blade operation control unit includes: Before the blade target position is set by the target position setting unit, a command for raising and lowering the blade so that the blade load approaches the first load threshold while following an increasing process close to the target trajectory is issued. It may be configured to output.
  • the target trajectory is set as in this aspect, even before the blade target position is set, the blade load approaches the first load threshold while following an increasing process close to the target trajectory.
  • the change in the amount of soil on the blade with respect to the travel distance of the work machine is small, and the change in the blade load is also small.
  • the effect of suppressing undulation on the construction surface can be further enhanced.
  • the blade target position is set by the target position setting unit. Is done.
  • the blade operation control unit controls the raising / lowering operation of the blade so that the positional deviation between the blade position and the blade target position approaches zero.
  • the blade control device further includes a load threshold setting unit that sets the first load threshold
  • the position information acquisition unit includes a vehicle body position acquisition unit that acquires a vehicle body position that is a position of the machine main body
  • the threshold setting unit is configured such that the main body distance is smaller than the first distance than when the main body distance that is a distance between the vehicle body position acquired by the vehicle body position acquisition unit and the target design surface is a first distance.
  • the first load threshold may be updated such that the first load threshold becomes smaller when the distance is the second distance.
  • the blade load when the main body distance is the second distance (that is, when the machine main body is close to the target design surface), when the main body distance is the first distance (that is, the machine main body) Is far from the target design surface), the blade load more easily reaches the first load threshold.
  • the first load threshold when the leveling operation is performed in the final stage of the operation by the work machine is set to a value smaller than the first load threshold when the excavation operation is performed in the initial stage or the intermediate stage of the operation. Is set.
  • the same control algorithm can be used for both the excavation operation where quick excavation work is more important than the leveling operation and the leveling operation where emphasis is placed on the accuracy of bringing the construction surface closer to the target design surface. become.
  • the blade operation control unit includes, as a variable, a position deviation that is a height difference between the blade position and the blade target position, based on a function having a term including a position gain that is multiplied by the position deviation.
  • the blade control device further includes a position gain setting unit that sets the position gain, wherein the position gain setting unit sets the position when the blade position is lower than the blade target position.
  • the position gain is updated such that the rising speed of the blade increases based on the deviation.
  • the effect of suppressing the ground to be excavated from being excavated below the blade target position is further enhanced.
  • the effect of suppressing the ground from being excavated below the target design surface is further enhanced.
  • the function further includes a term including a load deviation that is a deviation obtained by subtracting the second load threshold from the blade load as a variable and including a load gain by which the load deviation is multiplied.
  • the blade control device further includes a load gain setting unit configured to set the load gain, wherein the load gain setting unit is configured to control the blade based on the load deviation when the blade load is greater than the second load threshold. It is preferable to update the load gain so that the rising speed of the load increases. In this aspect, when the blade load is greater than the second load threshold, the blade ascending speed is increased, so that the blade load is reduced more quickly, a stack or the like due to an excessive load is prevented, and the working machine is stabilized. The effect of enabling traveling can be further enhanced.

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  • Mining & Mineral Resources (AREA)
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  • Operation Control Of Excavators (AREA)

Abstract

A blade control device (100), wherein a blade operation control unit (15) outputs instructions for raising and lowering a blade (4) so that the position deviation (Δx) between the blade position (x) calculated by a blade position arithmetic logic unit (12) and a blade target position (xref) approaches zero when the blade load (f) is less than or equal to a second load threshold value (f2), and outputs an instruction for raising the blade (4) when the blade load (f) is greater than the second load threshold value (f2). When a preset update condition in which the blade load (f) and a first load threshold value (f1) are associated with each other is met, a target position setting unit (14) updates the blade target position (xref) by referencing the blade position (x) at the time that the update condition is met.

Description

作業機械のブレード制御装置Work machine blade controller
　本発明は、ブレードを備えた作業機械に設けられるブレード制御装置に関する。 The present invention relates to a blade control device provided in a work machine having a blade.
　従来、地面の掘削、整地、土砂の運搬などに使用されるブレードを備える作業機械が広く用いられている。特許文献１は、ブレードにかかるブレード負荷がほぼ一定になるようにブレードの上昇及び下降の動作を自動制御するブルドーザの負荷制御装置を開示している。しかし、特許文献１に記載の負荷制御装置では、ブレードを昇降させることにより発生する施工面のうねりが課題となる。 作業 Conventionally, work machines equipped with blades used for excavating the ground, leveling the ground, and transporting earth and sand have been widely used. Patent Literature 1 discloses a bulldozer load control device that automatically controls the raising and lowering operations of a blade so that the blade load applied to the blade becomes substantially constant. However, in the load control device described in Patent Literature 1, the undulation of the construction surface caused by moving the blade up and down becomes a problem.
　特許文献２は、特許文献１の上記課題に対処するためのブレード制御装置を開示している。特許文献２は、ブレードが仮想設計面よりも設計面に近づかないように当該ブレードが制御され、ブレードが大きく下降することを抑えることができることを開示し、これにより連続したうねりが掘削面に形成されることを抑制できることを開示している。特許文献２に記載のブレード制御装置では、ブレード負荷が第１の設定負荷値よりも小さい場合にブレードを下降させ、ブレード負荷が前記第１の設定負荷値よりも大きな第２の設定負荷値よりも大きい場合にブレードを上昇させる。すなわち、特許文献２に記載のブレード制御装置では、ブレードの昇降動作は、ブレード負荷と第１の設定負荷値及び第２の設定負荷値との比較に基づいて制御される。 Patent Document 2 discloses a blade control device for addressing the above-described problem of Patent Document 1. Patent Document 2 discloses that the blade is controlled so that the blade does not approach the design surface more than the virtual design surface, and that the blade can be prevented from descending greatly, whereby a continuous swell is formed on the excavation surface. It is disclosed that this can be suppressed. In the blade control device described in Patent Literature 2, when the blade load is smaller than the first set load value, the blade is lowered, and the blade load is changed from the second set load value larger than the first set load value. Raise the blade if too big. That is, in the blade control device described in Patent Literature 2, the raising / lowering operation of the blade is controlled based on a comparison between the blade load and the first set load value and the second set load value.
　上記のような特許文献２に記載のブレード制御装置では、ブレードが仮想設計面よりも上方にあるときには、当該ブレードの昇降動作は、ブレード負荷に基づいて制御され、ブレードの位置に基づいて制御されるわけではないので、施工面のうねりは、ブレード負荷の増減に大きく左右される。このため、特許文献２のブレード制御装置では、施工面のうねりを抑制する効果は限定的になるため必ずしも十分とは言えない。 In the blade control device described in Patent Literature 2 described above, when the blade is located above the virtual design surface, the raising / lowering operation of the blade is controlled based on the blade load, and controlled based on the position of the blade. Therefore, the undulation of the construction surface largely depends on the increase and decrease of the blade load. For this reason, in the blade control device of Patent Literature 2, the effect of suppressing the undulation of the construction surface is limited, and is not necessarily sufficient.
特許第３５３７１８２号公報Japanese Patent No. 3537182 特許第５２８５８０５号公報Japanese Patent No. 5285805
　本発明は、ブレードを備えた作業機械に設けられ、前記ブレードの昇降動作を制御するためのブレード制御装置であって、施工面のうねりを効果的に抑制することができるブレード制御装置を提供することを目的とする。 The present invention provides a blade control device provided in a work machine equipped with a blade for controlling the raising and lowering operation of the blade, wherein the blade control device can effectively suppress undulation of a construction surface. The purpose is to:
　提供されるのは、機械本体と前記機械本体に対して昇降可能に取り付けられたブレードとを備えた作業機械に設けられ、前記ブレードの昇降動作を制御するためのブレード制御装置であって、前記ブレードによる掘削対象の目標形状を特定する目標設計面を設定する目標設計面設定部と、前記作業機械に関する位置情報を取得する位置情報取得部と、前記位置情報取得部により取得された前記位置情報に基づいて、グローバル座標系における前記ブレードの位置であるブレード位置を演算するブレード位置演算部と、前記ブレードにかかる負荷であるブレード負荷を取得するブレード負荷取得部と、前記ブレード負荷の閾値である第１負荷閾値及び前記ブレード負荷の閾値であって前記第１負荷閾値よりも大きい第２負荷閾値を記憶する記憶部と、前記ブレード位置の目標となる位置であって前記目標設計面よりも上方の位置であるブレード目標位置を設定する目標位置設定部と、前記ブレード負荷取得部により取得された前記ブレード負荷が前記第２負荷閾値以下の場合には、前記ブレード位置演算部により演算された前記ブレード位置と前記ブレード目標位置との偏差である位置偏差がゼロに近づくように前記ブレードを昇降させるための指令を出力し、前記ブレード負荷取得部により取得された前記ブレード負荷が前記第２負荷閾値よりも大きい場合には、前記ブレードを上昇させるための指令を出力するブレード動作制御部と、を備え、前記目標位置設定部は、前記ブレード負荷と前記第１負荷閾値とを関連づけて予め設定された更新条件が満たされた場合に、当該更新条件が満たされたときの前記ブレード位置を基準にして前記ブレード目標位置を更新する。 Provided is a blade control device provided on a work machine including a machine main body and a blade attached to the machine main body so as to be able to move up and down, and controlling a raising and lowering operation of the blade, A target design surface setting unit that sets a target design surface that specifies a target shape to be excavated by the blade, a position information acquisition unit that acquires position information about the work machine, and the position information that is acquired by the position information acquisition unit. A blade position calculating unit that calculates a blade position that is the position of the blade in a global coordinate system, a blade load obtaining unit that obtains a blade load that is a load applied to the blade, and a threshold value of the blade load. A first load threshold and a second load threshold that is a threshold of the blade load and is larger than the first load threshold. Part, a target position of the blade position, a target position setting unit that sets a blade target position that is a position above the target design surface, the blade load acquired by the blade load acquisition unit is In the case of being equal to or less than the second load threshold, a command for raising and lowering the blade is issued so that a position deviation, which is a deviation between the blade position and the blade target position calculated by the blade position calculator, approaches zero. Output, when the blade load acquired by the blade load acquisition unit is greater than the second load threshold, a blade operation control unit that outputs a command to raise the blade, comprising: The position setting unit associates the blade load with the first load threshold, and when an update condition set in advance is satisfied, the update is performed. Based on the said blade position when matter is met to update the blade target position.
本発明の実施の形態に係るブレード制御装置が搭載される作業機械の例である油圧ショベルを示す側面図である。1 is a side view illustrating a hydraulic excavator as an example of a work machine on which a blade control device according to an embodiment of the present invention is mounted. 前記ブレード制御装置の主要な機能を示すブロック図である。FIG. 3 is a block diagram illustrating main functions of the blade control device. 前記ブレード制御装置において、ブレード位置、ブレード目標位置、及びブレードの昇降動作の関係を示すグラフである。5 is a graph showing a relationship between a blade position, a blade target position, and a blade elevating operation in the blade control device. 前記ブレード制御装置において、ブレード負荷、第１負荷閾値、第２負荷閾値、及びブレードの昇降動作の関係を示すグラフである。4 is a graph showing a relationship among a blade load, a first load threshold, a second load threshold, and a blade elevating operation in the blade control device. 前記ブレード制御装置に含まれるコントローラが実行する制御動作の一例を示すフローチャートである。4 is a flowchart illustrating an example of a control operation executed by a controller included in the blade control device. 前記ブレード制御装置において、ブレード負荷の目標軌跡（目標軌道）と実際のブレード負荷の推移とを示すグラフである。4 is a graph showing a target locus (target trajectory) of a blade load and a transition of an actual blade load in the blade control device. 前記ブレード制御装置において、ブレード負荷に基づいて更新されるブレード目標位置について説明するためのタイムチャートの一例である。5 is an example of a time chart for explaining a blade target position updated based on a blade load in the blade control device. 前記ブレード制御装置において、ブレード負荷に基づいて更新されるブレード目標位置について説明するためのタイムチャートの他の例である。9 is another example of a time chart for explaining a blade target position updated based on a blade load in the blade control device. 前記ブレード制御装置において、機械本体の車***置と目標設計面との距離に基づいて第１負荷閾値を更新することを説明するための概略図である。FIG. 7 is a schematic diagram for explaining updating of a first load threshold based on a distance between a vehicle body position of a machine main body and a target design surface in the blade control device. 前記ブレード制御装置において、機械本体の車***置と目標設計面との距離に基づいて第１負荷閾値を更新することを説明するためのグラフである。6 is a graph for explaining updating of a first load threshold based on a distance between a vehicle body position of a machine body and a target design surface in the blade control device. 前記ブレード制御装置において、ブレード位置とブレード目標位置との偏差に基づいて位置ゲインを更新することを説明するためのグラフである。9 is a graph for explaining that the blade control device updates a position gain based on a deviation between a blade position and a blade target position. 前記ブレード制御装置において、ブレード負荷と第２負荷閾値との偏差に基づいて負荷ゲインを更新することを説明するためのグラフである。9 is a graph for explaining that the blade controller updates a load gain based on a deviation between a blade load and a second load threshold. 前記ブレード制御装置を備えた作業機械による施工面と、従来の作業機械による施工面とを比較した概略図である。It is the schematic which compared the construction surface by the working machine provided with the said blade control apparatus, and the construction surface by the conventional working machine.
　本発明の好ましい実施の形態を、図面を参照しながら説明する。 好 ま し い Preferred embodiments of the present invention will be described with reference to the drawings.
　［作業機械の全体構造］
　図１は、本発明の実施の形態に係るブレード制御装置が搭載される作業機械の例である油圧ショベル１を示す側面図である。この油圧ショベル１は、地面Ｇの上を走行可能な走行装置２（下部走行体）と、前記走行装置２に搭載される車体３（上部旋回体）と、車体３に搭載される作業装置と、走行装置２又は車体３に搭載されるブレード４と、を備える。前記走行装置２及び前記車体３は、前記作業機械の機械本体を構成する。前記車体３は、旋回フレーム、エンジン、運転室などを有する。 [Overall structure of work machine]
FIG. 1 is a side view showing a hydraulic excavator 1 as an example of a work machine on which a blade control device according to an embodiment of the present invention is mounted. The hydraulic excavator 1 includes a traveling device 2 (a lower traveling body) that can travel on the ground G, a vehicle body 3 (an upper revolving superstructure) mounted on the traveling device 2, and a working device mounted on the vehicle body 3. And a blade 4 mounted on the traveling device 2 or the vehicle body 3. The traveling device 2 and the vehicle body 3 constitute a machine body of the work machine. The vehicle body 3 has a turning frame, an engine, a cab, and the like.
　前記車体３に搭載される前記作業装置は、ブーム５、アーム６及びバケット７を含む。前記ブーム５は、前記旋回フレームの前端に起伏可能すなわち水平軸回りに回動可能に支持される基端部と、その反対側の先端部と、を有する。前記アーム６は、前記ブーム５の先端部に水平軸回りに回動可能に取付けられる基端部と、その反対側の先端部と、を有する。前記バケット７は、前記アーム６の先端部に回動可能に取付けられる。 The working device mounted on the vehicle body 3 includes a boom 5, an arm 6, and a bucket 7. The boom 5 has a base end supported at the front end of the revolving frame so as to be able to undulate, that is, rotatable around a horizontal axis, and a tip end on the opposite side. The arm 6 has a base end that is rotatably mounted on the front end of the boom 5 about a horizontal axis, and a front end opposite to the base end. The bucket 7 is rotatably attached to the tip of the arm 6.
　油圧ショベル１は、ブーム５、アーム６及びバケット７のそれぞれについて設けられるブームシリンダ、アームシリンダ及びバケットシリンダを有する。前記ブームシリンダは、前記車体３と前記ブーム５との間に介在し、当該ブーム５に起伏動作を行わせるように伸縮する。前記アームシリンダは、前記ブーム５と前記アーム６との間に介在し、当該アーム６に回動動作を行わせるように伸縮する。前記バケットシリンダは、前記アーム６と前記バケット７との間に介在し、当該バケット７に回動動作を行わせるように伸縮する。 The hydraulic excavator 1 has a boom cylinder, an arm cylinder, and a bucket cylinder provided for each of the boom 5, the arm 6, and the bucket 7. The boom cylinder is interposed between the vehicle body 3 and the boom 5, and extends and contracts so as to cause the boom 5 to perform an up-and-down operation. The arm cylinder is interposed between the boom 5 and the arm 6, and expands and contracts so as to cause the arm 6 to perform a rotating operation. The bucket cylinder is interposed between the arm 6 and the bucket 7, and expands and contracts so as to cause the bucket 7 to perform a rotating operation.
　前記走行装置２又は車体３に搭載される前記ブレード４は、地面の掘削、整地、土砂の運搬などの作業を行うために設けられている。具体的には、ブレード４は、リフトフレーム４ａに支持されており、当該リフトフレーム４ａは、走行装置２に対して水平軸４ｂ回りに回動可能に支持されている。したがって、ブレード４は、走行装置２に対して上下方向に変位することができる。 The blade 4 mounted on the traveling device 2 or the vehicle body 3 is provided for performing operations such as excavation of the ground, leveling, and transportation of earth and sand. Specifically, the blade 4 is supported by a lift frame 4a, and the lift frame 4a is supported rotatably about the horizontal axis 4b with respect to the traveling device 2. Therefore, the blade 4 can be displaced vertically with respect to the traveling device 2.
　油圧ショベル１は、ブレード４について設けられるリフトシリンダ８を有する。当該リフトシリンダ８は、ヘッド側室８ｈ及びロッド側室８ｒ（図１参照）を有し、当該ヘッド側室８ｈに作動油が供給されることにより伸長してブレード４を下げ方向に動かすとともに前記ロッド側室８ｒ内の作動油を排出する一方、前記ロッド側室８ｒに作動油が供給されることにより収縮してブレード４を上げ方向に動かすとともに前記ヘッド側室８ｈ内の作動油を排出する。 The excavator 1 has a lift cylinder 8 provided for the blade 4. The lift cylinder 8 has a head-side chamber 8h and a rod-side chamber 8r (see FIG. 1). When hydraulic oil is supplied to the head-side chamber 8h, the lift cylinder 8 extends to move the blade 4 in a lowering direction and to move the rod-side chamber 8r. While the hydraulic oil in the inside is discharged, the hydraulic oil is supplied to the rod side chamber 8r to contract and move the blade 4 in the upward direction, and to discharge the hydraulic oil in the head side chamber 8h.
　油圧ショベル１は、図略の油圧回路を有する。前記油圧回路は、前記ブームシリンダ、前記アームシリンダ、前記バケットシリンダ、及び前記リフトシリンダ８を含む。また、前記油圧回路は、油圧ポンプ９（図１参照）と、リフトシリンダ制御用比例弁４１（図２参照）と、図略のリフトシリンダ流量制御弁と、をさらに含む。 The hydraulic excavator 1 has a hydraulic circuit (not shown). The hydraulic circuit includes the boom cylinder, the arm cylinder, the bucket cylinder, and the lift cylinder 8. The hydraulic circuit further includes a hydraulic pump 9 (see FIG. 1), a lift cylinder control proportional valve 41 (see FIG. 2), and a lift cylinder flow control valve (not shown).
　［ブレード制御装置］
　図２は、ブレード制御装置１００の主要な機能を示すブロック図である。ブレード制御装置１００は、ブレード４の昇降動作を制御するために設けられている。ブレード制御装置１００は、コントローラ１０（メカトロコントローラ）と、位置情報取得部と、ブレード負荷取得部３４と、自動制御スイッチ３５と、走行装置２を操作するための走行レバー３６と、を備える。前記コントローラ１０は、例えばマイクロコンピュータからなり、前記油圧回路に含まれる各要素の動作を制御する。 [Blade control unit]
FIG. 2 is a block diagram illustrating main functions of the blade control device 100. The blade control device 100 is provided to control the elevating operation of the blade 4. The blade control device 100 includes a controller 10 (mechatronic controller), a position information acquisition unit, a blade load acquisition unit 34, an automatic control switch 35, and a traveling lever 36 for operating the traveling device 2. The controller 10 includes, for example, a microcomputer and controls the operation of each element included in the hydraulic circuit.
　前記位置情報取得部は、油圧ショベル１に関する位置情報を取得する機能を有する。具体的には、本実施形態では、前記位置情報取得部は、車***置取得部３１と、車体角度取得部３２と、ブレード角度取得部３３と、を含む。前記車***置取得部３１は、前記機械本体の位置である車***置を取得する機能を有する。前記車***置取得部３１は、例えばＧＮＳＳ（Ｇｌｏｂａｌ　Ｎａｖｉｇａｔｉｏｎ　Ｓａｔｅｌｌｉｔｅ　Ｓｙｓｔｅｍ）のレシーバ（ＧＮＳＳセンサ）のように衛星測位システムから衛星データ（測位信号）を受信可能なレシーバなどによって構成され、グローバル座標系における機械本体の位置を示すＧＮＳＳデータを受信する。前記グローバル座標系は、地球に規定された原点を基準とする３次元の座標系であって、前記衛星測位システムにより規定される絶対位置を示す座標系である。 位置 The position information acquisition unit has a function of acquiring position information on the excavator 1. Specifically, in the present embodiment, the position information acquisition unit includes a vehicle body position acquisition unit 31, a vehicle body angle acquisition unit 32, and a blade angle acquisition unit 33. The vehicle body position acquisition unit 31 has a function of acquiring a vehicle body position that is the position of the machine body. The vehicle body position acquisition unit 31 is configured by a receiver capable of receiving satellite data (positioning signal) from a satellite positioning system, such as a receiver (GNSS sensor) of GNSS (Global Navigation Satellite System), and is a machine in a global coordinate system. GNSS data indicating the position of the main body is received. The global coordinate system is a three-dimensional coordinate system based on an origin defined on the earth, and is a coordinate system indicating an absolute position defined by the satellite positioning system.
　車体角度取得部３２は、前記機械本体の角度を取得する機能を有する。車体角度取得部３２は、例えばグローバル座標系における機械本体の角度（本実施形態では、車体３の角度）を検出する車体角度センサによって構成されている。具体的に、当該車体角度センサは、例えば前記機体本体に設けられ、衛星測位システムから衛星データ（測位信号）を受信可能な１つ又は複数のレシーバにより構成されていてもよい。 The vehicle body angle acquisition unit 32 has a function of acquiring the angle of the machine body. The vehicle body angle acquisition unit 32 is configured by, for example, a vehicle body angle sensor that detects the angle of the machine main body in the global coordinate system (in the present embodiment, the angle of the vehicle body 3). Specifically, the vehicle body angle sensor may be provided, for example, in the body of the aircraft, and may include one or a plurality of receivers capable of receiving satellite data (positioning signal) from a satellite positioning system.
　前記ブレード角度取得部３３は、前記ブレード４の角度を取得する機能を有する。ブレード角度取得部３３は、例えばグローバル座標系におけるブレード４の角度を検出するブレード角度センサによって構成されている。具体的に、当該ブレード角度センサは、例えば前記機体本体に設けられ、衛星測位システムから衛星データ（測位信号）を受信可能な１つ又は複数のレシーバにより構成されていてもよい。 ブ レ ー ド The blade angle acquisition unit 33 has a function of acquiring the angle of the blade 4. The blade angle acquisition unit 33 is configured by, for example, a blade angle sensor that detects the angle of the blade 4 in the global coordinate system. Specifically, the blade angle sensor may be provided in, for example, the body of the aircraft, and may be configured by one or a plurality of receivers capable of receiving satellite data (positioning signal) from a satellite positioning system.
　なお、前記グローバル座標系に代えて、前記車***置を基準とする３次元の座標系、作業現場における特定位置を基準とする３次元の座標系などのローカル座標系が用いられてもよく、前記グローバル座標系と前記ローカル座標系とが併用されてもよい。この場合、前記車体角度センサは、例えば慣性計測装置により構成されていてもよく、当該慣性計測装置と前記衛星データを受信可能な前記レシーバとにより構成されていてもよい。前記慣性計測装置は、例えば、車体３の加速度および角速度を計測し、計測結果に基づいて車体３の傾き（例えば、Ｘ軸に対する回転を表すピッチ、Ｙ軸に対する回転を表すヨーおよびＺ軸に対する回転を表すロール）を検出可能に構成されていてもよい。また、前記ブレード角度センサは、例えばブレードシリンダ８のシリンダストロークを検出するストロークセンサにより構成されていてもよく、当該ストロークセンサと前記衛星データを受信可能な前記レシーバとにより構成されていてもよい。 Note that, instead of the global coordinate system, a local coordinate system such as a three-dimensional coordinate system based on the vehicle body position or a three-dimensional coordinate system based on a specific position in a work site may be used. The global coordinate system and the local coordinate system may be used together. In this case, the vehicle body angle sensor may be configured by, for example, an inertial measurement device, or may be configured by the inertial measurement device and the receiver that can receive the satellite data. The inertial measurement device measures, for example, the acceleration and angular velocity of the vehicle body 3, and based on the measurement result, tilts the vehicle body 3 (for example, pitch indicating rotation about the X axis, yaw indicating rotation about the Y axis, and rotation about the Z axis). May be configured to be detectable. Further, the blade angle sensor may be configured by, for example, a stroke sensor that detects a cylinder stroke of the blade cylinder 8, or may be configured by the stroke sensor and the receiver that can receive the satellite data.
　図１に示すように、本実施形態では、車***置取得部３１及び車体角度取得部３２は車体３の上部に取り付けられており、ブレード角度取得部３３はブレード４の上部に取り付けられるが、これらの取り付け位置は図１に示す具体例に限られない。これらの取得部３１，３２，３３により生成される電気信号である検出信号は、前記コントローラ１０に入力される。 As shown in FIG. 1, in the present embodiment, the vehicle body position obtaining unit 31 and the vehicle body angle obtaining unit 32 are mounted on the upper part of the vehicle body 3, and the blade angle obtaining unit 33 is mounted on the upper part of the blade 4. Is not limited to the specific example shown in FIG. Detection signals, which are electric signals generated by the acquisition units 31, 32, and 33, are input to the controller 10.
　本実施形態では、前記ブレード負荷取得部３４は、掘削作業時に前記ブレード４にかかる負荷であるブレード負荷を取得する機能を有する。当該ブレード負荷は、例えばブレード４を駆動する油圧ポンプ９のポンプ圧に対応するものである。したがって、ブレード負荷取得部３４は、前記ポンプ圧を検出することにより前記ブレード負荷を検出可能である。本実施形態では、前記ブレード負荷取得部３４は、リフトシリンダ８のヘッド側室８ｈにおける作動油の圧力であるヘッド圧Ｐ１を検出するヘッド圧センサ３４Ｈと、リフトシリンダ８のロッド側室８ｒにおける作動油の圧力であるロッド圧Ｐ２を検出するロッド圧センサ３４Ｒと、を含む。前記センサ３４Ｈ及び３４Ｒのそれぞれは、その検出した物理量をこれに対応する電気信号である検出信号に変換して前記コントローラ１０に入力する。 In the present embodiment, the blade load obtaining unit 34 has a function of obtaining a blade load that is a load applied to the blade 4 during excavation work. The blade load corresponds to, for example, the pump pressure of the hydraulic pump 9 that drives the blade 4. Therefore, the blade load acquisition unit 34 can detect the blade load by detecting the pump pressure. In the present embodiment, the blade load acquisition unit 34 includes a head pressure sensor 34H that detects a head pressure P1 that is a pressure of hydraulic oil in the head-side chamber 8h of the lift cylinder 8, and a hydraulic pressure in the rod-side chamber 8r of the lift cylinder 8. And a rod pressure sensor 34R for detecting a rod pressure P2 as a pressure. Each of the sensors 34H and 34R converts the detected physical quantity into a detection signal, which is an electric signal corresponding to the detected physical quantity, and inputs the detection signal to the controller 10.
　自動制御スイッチ３５は、運転室内に配置されるとともに、前記コントローラ１０に電気的に接続される。当該自動制御スイッチ３５は、前記コントローラ１０の制御モードを手動操作モードから自動制御モードに切換えるための操作を受けて当該操作に係るモード指令信号を前記コントローラ１０に入力する。前記コントローラ１０は、制御モードの設定を、前記自動制御スイッチ３５から入力されるモード指令信号により前記手動操作モードから前記自動制御モードに切換える。 The automatic control switch 35 is arranged in the cab and is electrically connected to the controller 10. The automatic control switch 35 receives an operation for switching the control mode of the controller 10 from the manual operation mode to the automatic control mode, and inputs a mode command signal relating to the operation to the controller 10. The controller 10 switches the setting of the control mode from the manual operation mode to the automatic control mode according to a mode command signal input from the automatic control switch 35.
　前記自動制御モードでは、当該コントローラ１０は、ブレード４により施工される施工面が予め設定された目標設計面に近づくように前記リフトシリンダ８の動作を自動制御するように構成されている。リフトシリンダ８の動作を制御するための前記リフトシリンダ制御用比例弁４１への指令値（指令電流）が当該コントローラ１０から出力されると、当該指令値に応じて比例弁４１の２次圧が変化し、その２次圧に応じて前記リフトシリンダ流量制御弁の開度が変化する。その結果、前記油圧ポンプ９から前記リフトシリンダ流量制御弁を介してリフトシリンダ８へ供給される作動油の供給流量及び供給方向が変化し、リフトシリンダ８の動作速度や駆動方向が制御される。一方、前記手動操作モードでは、作業者が走行レバー３６を操作すると、その操作信号がコントローラ１０に入力され、ブレード４の昇降を操作するための図略の操作レバーの操作量に応じて、前記リフトシリンダ制御用比例弁４１への指令値又は前記リフトシリンダ流量制御弁への指令値が当該コントローラ１０から出力される。 In the automatic control mode, the controller 10 is configured to automatically control the operation of the lift cylinder 8 so that the construction surface constructed by the blade 4 approaches a preset target design surface. When a command value (command current) to the lift cylinder control proportional valve 41 for controlling the operation of the lift cylinder 8 is output from the controller 10, the secondary pressure of the proportional valve 41 is increased according to the command value. The opening degree of the lift cylinder flow control valve changes according to the secondary pressure. As a result, the supply flow rate and the supply direction of the hydraulic oil supplied from the hydraulic pump 9 to the lift cylinder 8 via the lift cylinder flow control valve change, and the operation speed and the drive direction of the lift cylinder 8 are controlled. On the other hand, in the manual operation mode, when an operator operates the traveling lever 36, an operation signal is input to the controller 10, and the operation signal is input to the controller 10 according to the operation amount of an unillustrated operation lever for operating the elevation of the blade 4. A command value to the lift cylinder control proportional valve 41 or a command value to the lift cylinder flow control valve is output from the controller 10.
　前記コントローラ１０は、前記自動制御を実行するための機能として、目標設計面設定部１１と、ブレード位置演算部１２と、記憶部１３と、目標位置設定部１４と、ブレード動作制御部１５と、負荷閾値設定部１６と、位置ゲイン設定部１７と、負荷ゲイン設定部１８と、距離演算部１９と、を有する。 The controller 10 includes a target design surface setting unit 11, a blade position calculation unit 12, a storage unit 13, a target position setting unit 14, a blade operation control unit 15, as functions for executing the automatic control. It has a load threshold setting unit 16, a position gain setting unit 17, a load gain setting unit 18, and a distance calculation unit 19.
　前記目標設計面設定部１１は、前記ブレード４による掘削対象の目標形状を特定する目標設計面（図９参照）を設定する。前記目標設計面設定部１１は、前記運転室内に設けられた目標設計面入力部により入力された設計面を記憶し、当該設計面を目標設計面に設定してもよい。また、前記目標設計面設定部１１は、各種記憶媒体、通信ネットワークなどを介して取得した設計面のデータを記憶し、当該設計面を目標設計面に設定してもよい。前記目標設計面設定部１１は、設定した目標設計面を目標位置設定部１４に入力する。前記目標設計面は、掘削対象である地盤の目標形状であって３次元の設計地形を特定する面である。当該目標設計面は、ＢＩＭ、ＣＩＭ（Ｂｕｉｌｄｉｎｇ／Ｃｏｎｓｔｒｕｃｔｉｏｎ　Ｉｎｆｏｒｍａｔｉｏｎ　Ｍｏｄｅｌｉｎｇ，Ｍａｎａｇｅｍｅｎｔ）などの外部データによって特定されてもよいし、作業機械の位置を基準にして設定されたものでもよい。 目標 The target design surface setting unit 11 sets a target design surface (see FIG. 9) for specifying a target shape to be excavated by the blade 4. The target design surface setting unit 11 may store a design surface input by a target design surface input unit provided in the cab, and may set the design surface as a target design surface. Further, the target design surface setting unit 11 may store design surface data acquired via various storage media, a communication network, or the like, and set the design surface as a target design surface. The target design plane setting unit 11 inputs the set target design plane to the target position setting unit 14. The target design surface is a surface for specifying a three-dimensional design terrain, which is a target shape of the ground to be excavated. The target design surface may be specified by external data such as BIM or CIM (Building / Construction / Information / Modeling, Management), or may be set based on the position of the work machine.
　前記ブレード位置演算部１２は、前記位置情報取得部により取得された前記位置情報に基づいて、グローバル座標系における前記ブレード４の位置であるブレード位置ｘを演算する。本実施形態では、ブレード位置演算部１２は、車***置取得部３１により取得された前記車***置と、車体角度取得部３２により取得された前記機械本体の角度と、ブレード角度取得部３３により取得された前記ブレード４の角度とに基づいて、前記ブレード位置ｘを演算する。すなわち、基準点から前記車***置までのベクトルと前記車***置から前記ブレード位置までのベクトルとの和から前記ブレード位置ｘが演算される。このように本実施形態では、グローバル座標系における前記機械本体の角度と前記ブレード４の角度の相対角度によりブレード位置ｘを演算しているが、ブレード位置ｘの演算方法はこれに限られない。ブレード位置ｘは、例えばリフトシリンダ８の長さに基づいて演算されてもよく、ブレード４にＧＮＳＳのレシーバ（ＧＮＳＳセンサ）を取り付け、当該ＧＮＳＳセンサが受信するＧＮＳＳデータに基づいて演算されてもよい。 The blade position calculation unit 12 calculates a blade position x, which is a position of the blade 4 in a global coordinate system, based on the position information acquired by the position information acquisition unit. In the present embodiment, the blade position calculating unit 12 obtains the vehicle body position obtained by the vehicle body position obtaining unit 31, the angle of the machine body obtained by the vehicle body angle obtaining unit 32, and the blade position obtaining unit 33. The blade position x is calculated based on the angle of the blade 4. That is, the blade position x is calculated from the sum of a vector from the reference point to the vehicle body position and a vector from the vehicle body position to the blade position. As described above, in the present embodiment, the blade position x is calculated based on the relative angle between the angle of the machine body and the angle of the blade 4 in the global coordinate system, but the method of calculating the blade position x is not limited to this. The blade position x may be calculated based on, for example, the length of the lift cylinder 8, or a GNSS receiver (GNSS sensor) may be attached to the blade 4 and calculated based on GNSS data received by the GNSS sensor. .
　本実施形態では、前記ブレード位置ｘは、ブレード４の先端である刃先位置（ブレード４の先端の下縁の位置）に設定されているが、ブレード４の他の部位に設定されていてもよい。 In the present embodiment, the blade position x is set at the cutting edge position, which is the tip of the blade 4 (the position of the lower edge of the tip of the blade 4), but may be set at another part of the blade 4. .
　前記記憶部１３は、前記ブレード負荷ｆの閾値である第１負荷閾値ｆ１及び前記ブレード負荷ｆの閾値であって前記第１負荷閾値ｆ１よりも大きい第２負荷閾値ｆ２を記憶する。前記第１負荷閾値ｆ１は、油圧ショベル１が安定して走行可能な適正なブレード負荷ｆに対応する値に設定される。前記第２負荷閾値ｆ２は、ブレード負荷ｆが過大になってスタック等が発生するという事態の発生を未然に防止するために設定された値である。すなわち、第２負荷閾値ｆ２は、安定して効率のよい掘削動作を実現するために設定された値である。これらの負荷閾値ｆ１，ｆ２は、作業者が掘削作業前にコントローラ１０に手動で入力してもよく、掘削作業中にコントローラ１０により適宜演算されて記憶されるものであってもよい。 The storage unit 13 stores a first load threshold value f1 that is a threshold value of the blade load f and a second load threshold value f2 that is a threshold value of the blade load f and is larger than the first load threshold value f1. The first load threshold f1 is set to a value corresponding to an appropriate blade load f at which the excavator 1 can run stably. The second load threshold value f2 is a value set in order to prevent the occurrence of a situation in which the blade load f becomes excessive and a stack or the like occurs. That is, the second load threshold f2 is a value set to realize a stable and efficient excavation operation. These load thresholds f1 and f2 may be manually input to the controller 10 by the operator before the excavation work, or may be appropriately calculated and stored by the controller 10 during the excavation work.
　また、前記記憶部１３は、予め設定された更新条件を記憶する。当該更新条件は、前記ブレード負荷ｆと前記第１負荷閾値とを関連づけて予め設定された条件であり、前記目標位置設定部１４が前記ブレード目標位置ｘｒｅｆを更新するか否かを判定する基準となるものである。更新条件は、ブレード負荷ｆが第１負荷閾値ｆ１に近づいてこれらの偏差が十分に小さくなったことを条件に含む。本実施形態では、前記更新条件は、前記第１負荷閾値ｆ１に前記ブレード負荷ｆが到達するという条件、又は前記ブレード負荷ｆが前記第１負荷閾値ｆ１に近づいたことを判定するために前記第１負荷閾値ｆ１に基づいて設定された判定値に前記ブレード負荷ｆが到達するという条件を含む。前記判定値は、ブレード負荷ｆから第１負荷閾値ｆ１を引き算した偏差（ｆ－ｆ１）が十分に小さくなったことを判定可能な値である。当該判定値は、シミュレーションや実験などを通じて予め設定される閾値である。 (4) The storage unit 13 stores a preset update condition. The update condition is a condition that is set in advance by associating the blade load f with the first load threshold, and is a criterion for determining whether or not the target position setting unit 14 updates the blade target position xref. It becomes. The update condition includes the condition that the blade load f approaches the first load threshold value f1 and these deviations become sufficiently small. In the present embodiment, the update condition is a condition that the blade load f reaches the first load threshold value f1 or the second condition in order to determine that the blade load f approaches the first load threshold value f1. It includes a condition that the blade load f reaches a determination value set based on one load threshold f1. The determination value is a value that can determine that the deviation (f−f1) obtained by subtracting the first load threshold f1 from the blade load f is sufficiently small. The determination value is a threshold value set in advance through a simulation, an experiment, or the like.
　また、前記記憶部１３は、目標軌跡を記憶する（後述する図６参照）。当該目標軌跡は、前記ブレード負荷ｆが増加しながら前記第１負荷閾値ｆ１に近づくときの前記ブレード負荷ｆの増加プロセスの目標となるものである。当該目標軌跡は、自動制御モードが選択された掘削作業の開始時においてブレード目標位置ｘｒｅｆが設定されていない場合に、ブレード負荷ｆが第１負荷閾値ｆ１まで好ましい増加プロセスをたどって増加するようにブレード４の昇降動作を制御するために予め設定されたものである。 (4) The storage unit 13 stores a target trajectory (see FIG. 6 described later). The target trajectory is a target of an increasing process of the blade load f when the blade load f approaches the first load threshold f1 while increasing. The target trajectory is set such that the blade load f follows a preferred increase process up to the first load threshold f1 when the blade target position xref is not set at the start of the excavation operation in which the automatic control mode is selected. This is set in advance to control the elevating operation of the blade 4.
　前記目標位置設定部１４は、前記ブレード位置ｘの目標となる位置であって前記目標設計面よりも上方の位置であるブレード目標位置ｘｒｅｆを設定する。前記目標位置設定部１４は、例えば、前記ブレード負荷ｆと前記ブレード位置ｘとに基づいて前記ブレード目標位置ｘｒｅｆを設定する。 The target position setting unit 14 sets a target blade position xref, which is a target position of the blade position x and a position above the target design surface. The target position setting unit 14 sets the blade target position xref based on, for example, the blade load f and the blade position x.
　前記負荷閾値設定部１６は、前記第１負荷閾値ｆ１を設定する。前記位置ゲイン設定部１７は、前記位置ゲインｋｘを設定する。前記負荷ゲイン設定部１８は、前記負荷ゲインｋｆを設定する。これらの負荷閾値設定部１６、位置ゲイン設定部１７及び負荷ゲイン設定部１８の詳細については後述する。 The load threshold setting unit 16 sets the first load threshold f1. The position gain setting unit 17 sets the position gain kx. The load gain setting unit 18 sets the load gain kf. The details of the load threshold setting unit 16, the position gain setting unit 17, and the load gain setting unit 18 will be described later.
　前記ブレード動作制御部１５は、リフトシリンダ８の動作を制御するための前記リフトシリンダ制御用比例弁４１への指令値を演算し出力する。具体的には次の通りである。 The blade operation control unit 15 calculates and outputs a command value to the lift cylinder control proportional valve 41 for controlling the operation of the lift cylinder 8. Specifically, it is as follows.
　図３は、ブレード制御装置１００において、ブレード位置ｘ、ブレード目標位置ｘｒｅｆ、及びブレード４の昇降動作の関係を示すグラフである。前記ブレード動作制御部１５は、前記ブレード位置演算部１２により演算された前記ブレード位置ｘと前記ブレード目標位置ｘｒｅｆとの偏差である位置偏差Δｘがゼロに近づくように前記ブレード４を昇降させるための指令（指令値）を演算して出力する。 FIG. 3 is a graph showing the relationship between the blade position x, the blade target position xref, and the lifting / lowering operation of the blade 4 in the blade control device 100. The blade operation control unit 15 is for raising and lowering the blade 4 so that a position deviation Δx, which is a deviation between the blade position x calculated by the blade position calculation unit 12 and the blade target position xref, approaches zero. The command (command value) is calculated and output.
　ブレード位置ｘの制御は、ブレード位置ｘと、ブレード目標位置ｘｒｅｆとの偏差である位置偏差Δｘの大きさに応じて制御量を変化させるフィードバック制御である。具体的には、前記ブレード動作制御部１５は、前記ブレード位置ｘと前記ブレード目標位置ｘｒｅｆとの高低差である位置偏差Δｘを変数として含むとともに当該位置偏差Δｘに乗じる位置ゲインｋｘを含む項を有する関数に基づいて前記指令を演算して出力する。なお、図３において、ブレード目標位置ｘｒｅｆは、グラフの横軸における原点に対応する位置にあり、ハンチングを抑止するためのヒステリシスが与えられている。すなわち、ブレード位置ｘがブレード目標位置ｘｒｅｆを基準とした所定範囲（例えば、図３に示されるようにブレード目標位置ｘｒｅｆ±αの範囲）に含まれる場合には、ブレード動作制御部１５は、ブレード位置ｘの制御を行わない。 制 御 The control of the blade position x is feedback control that changes the control amount in accordance with the magnitude of the position deviation Δx, which is the deviation between the blade position x and the blade target position xref. Specifically, the blade operation control unit 15 includes, as a variable, a position deviation Δx which is a height difference between the blade position x and the blade target position xref, and a term including a position gain kx by which the position deviation Δx is multiplied. The command is calculated and output based on the function of the command. In FIG. 3, the blade target position xref is located at a position corresponding to the origin on the horizontal axis of the graph, and is provided with a hysteresis for suppressing hunting. That is, when the blade position x is included in a predetermined range based on the blade target position xref (for example, a range of the blade target position xref ± α as shown in FIG. 3), the blade operation control unit 15 Does not control the position x.
　図４は、ブレード制御装置１００において、ブレード負荷ｆ、第１負荷閾値ｆ１、第２負荷閾値ｆ２、及びブレード４の昇降動作の関係を示すグラフである。図４に示すように、ブレード動作制御部１５は、前記ブレード負荷取得部３４により取得された前記ブレード負荷ｆが前記第２負荷閾値ｆ２よりも大きい場合には、前記ブレード４を上昇させるための指令（指令値）を演算して出力する。具体的には、ブレード動作制御部１５は、例えば、前記ブレード負荷ｆから前記第２負荷閾値ｆ２を引き算することにより得られる偏差（ｆ－ｆ２）である負荷偏差Δｆを変数として含むとともに当該負荷偏差Δｆに乗じる負荷ゲインｋｆを含む項を有する関数に基づいて前記指令を演算し出力する。 FIG. 4 is a graph showing the relationship among the blade load f, the first load threshold f1, the second load threshold f2, and the lifting / lowering operation of the blade 4 in the blade control device 100. As shown in FIG. 4, when the blade load f acquired by the blade load acquisition unit 34 is larger than the second load threshold f2, the blade operation control unit 15 raises the blade 4. The command (command value) is calculated and output. Specifically, the blade operation control unit 15 includes, as a variable, a load deviation Δf which is a deviation (ff−2) obtained by subtracting the second load threshold value f2 from the blade load f, for example. The command is calculated and output based on a function having a term including the load gain kf multiplied by the deviation Δf.
　本実施形態では、図３に示すようなブレード４の位置制御が優先される。その一方で、ブレード負荷ｆが第２負荷閾値ｆ２よりも大きくなる場合には、ブレード４が速やかに上げ動作するようにブレード位置が制御される。このような位置制御優先の制御が行われることにより、施工面のうねりを抑制しつつ、安定した効率のよい掘削作業が可能になる。 In the present embodiment, the position control of the blade 4 as shown in FIG. 3 has priority. On the other hand, when the blade load f becomes larger than the second load threshold value f2, the blade position is controlled so that the blade 4 moves up quickly. By performing such position control priority control, stable and efficient excavation work can be performed while suppressing the undulation of the construction surface.
　次に、前記自動制御モードにおいて前記コントローラ１０が前記ブレード４の駆動について行う制御動作を、図５のフローチャートを参照しながら説明する。 Next, a control operation performed by the controller 10 for driving the blade 4 in the automatic control mode will be described with reference to a flowchart of FIG.
　コントローラ１０は、自動制御スイッチ３５がオンになっているか否か、すなわち、前記自動制御モードが選択されているか否かを判定する（ステップＳ１）。当該自動制御モードが選択されていない場合には（ステップＳ１においてＮＯ）、コントローラ１０は自動制御モードの制御を行わずに処理を終了する。 The controller 10 determines whether or not the automatic control switch 35 is turned on, that is, whether or not the automatic control mode is selected (Step S1). If the automatic control mode is not selected (NO in step S1), the controller 10 ends the process without performing the control in the automatic control mode.
　前記自動制御モードが選択されている場合には（ステップＳ１においてＹＥＳ）、コントローラ１０は、当該コントローラ１０に入力される信号、具体的には各センサの検出信号や指定信号を取り込む（ステップＳ２）。当該指定信号には、オペレータによる目標設計面の入力部の操作により指定される目標設計面についての信号や、ブレード負荷取得部３４により取得されるブレード負荷ｆについての信号、車***置取得部３１により取得される前記車***置についての信号、車体角度取得部３２により取得される前記機械本体の角度についての信号、ブレード角度取得部３３により取得される前記ブレード４の角度についての信号、走行レバー３６が受ける操作に対応する走行速度についての信号などが含まれる。これらの指定信号に基づき、前記コントローラ１０は、油圧ショベル１の初期状態を取得する。また、コントローラ１０の目標設計面設定部１１は、前記目標設計面についての前記信号に基づいて、目標設計面を設定する。 When the automatic control mode is selected (YES in step S1), the controller 10 captures a signal input to the controller 10, specifically, a detection signal or a designation signal of each sensor (step S2). . The designation signal includes a signal about a target design surface designated by an operation of an input unit of the target design surface by the operator, a signal about a blade load f acquired by the blade load acquisition unit 34, and a signal about the vehicle body position acquisition unit 31. The signal about the acquired vehicle body position, the signal about the angle of the machine main body acquired by the vehicle body angle acquisition unit 32, the signal about the angle of the blade 4 acquired by the blade angle acquisition unit 33, and the traveling lever 36 A signal about the traveling speed corresponding to the operation to be received is included. Based on these designation signals, the controller 10 acquires the initial state of the excavator 1. Further, the target design surface setting unit 11 of the controller 10 sets a target design surface based on the signal for the target design surface.
　次に、コントローラ１０は、ブレード目標位置ｘｒｅｆが設定されているか否かを判定する（ステップＳ３）。当該ブレード目標位置ｘｒｅｆが設定されていない場合（ステップＳ３においてＮＯ）、前記ブレード動作制御部１５は、前記ブレード負荷ｆが前記目標軌跡に近い増加プロセスをたどりながら前記第１負荷閾値ｆ１に近づくように前記ブレード４を昇降させるための指令を出力する（ステップＳ４）。本発明のブレード制御装置において前記目標軌跡の設定は必須のものではないが、本実施形態のように前記目標軌跡が設定され、当該目標軌跡に基づいてブレード位置ｘが制御されることにより、次のようなメリットがある。具体的には次の通りである。 Next, the controller 10 determines whether or not the blade target position xref has been set (Step S3). If the blade target position xref has not been set (NO in step S3), the blade operation control unit 15 causes the blade load f to approach the first load threshold f1 while following an increasing process close to the target trajectory. Then, a command for raising and lowering the blade 4 is output (step S4). Although the setting of the target trajectory is not essential in the blade control device of the present invention, the target trajectory is set as in the present embodiment, and the blade position x is controlled based on the target trajectory. There are advantages as follows. Specifically, it is as follows.
　図６は、前記ブレード制御装置１００において、ブレード負荷ｆの目標軌跡（目標軌道）と実際のブレード負荷ｆの推移とを示すグラフである。図６において一点鎖線で示される曲線は、前記目標軌跡（目標軌道）であり、実線で示される曲線は、実際のブレード負荷ｆの推移である。 FIG. 6 is a graph showing a target trajectory (target trajectory) of the blade load f and a transition of the actual blade load f in the blade control device 100. In FIG. 6, a curve shown by a dashed line is the target trajectory (target trajectory), and a curve shown by a solid line is a transition of the actual blade load f.
　図６に示すような前記目標軌跡が設定されていない場合には、ブレード目標位置ｘｒｅｆが設定される前の段階において掘削作業が開始されると、ブレード４が大きな降下速度で地中へ入り込むことがあり、ブレード負荷ｆが前記第１負荷閾値ｆ１に到達するときのブレード４の地中への入り込み深さが大きくなりやすい。かかる場合、油圧ショベル１の走行距離に対するブレード４上の土量の変化が大きく、ブレード負荷ｆの変動も大きくなることがある。 When the target trajectory as shown in FIG. 6 is not set, when the excavation operation is started at a stage before the blade target position xref is set, the blade 4 enters the ground at a large descent speed. Therefore, when the blade load f reaches the first load threshold value f1, the depth of penetration of the blade 4 into the ground tends to increase. In such a case, the change in the amount of soil on the blade 4 with respect to the traveling distance of the excavator 1 is large, and the fluctuation of the blade load f may be large.
　一方、本実施形態のように図６に示す目標軌跡が設定されている場合には、ブレード目標位置ｘｒｅｆが設定される前の段階においても、ブレード負荷ｆが前記目標軌跡に近い増加プロセスをたどりながら前記第１負荷閾値ｆ１に近づくので、ブレード４が適度な降下速度で地中へ入り込み、ブレード負荷ｆが前記第１負荷閾値ｆ１に到達するときのブレード４の地中への入り込み深さが大きくなるのを抑制できる。これにより、油圧ショベル１の走行距離に対するブレード４上の土量の変化が小さく、ブレード負荷ｆの変動も小さくなる。その結果、施工面のうねりを抑制する効果をより高めることができる。なお、前記目標軌跡（目標軌道）は、上記のようにブレード負荷ｆが前記第１負荷閾値ｆ１に徐々に近づくように前記ブレード負荷ｆを制御可能なものであればよく、具体的な目標軌跡は特に限定されない。前記目標軌跡（目標軌道）は、例えば図６において一点鎖線で示されるようにブレード負荷ｆが前記第１負荷閾値ｆ１に徐々に近づくような曲線軌道を表す関数によって与えられてもよい。また、前記目標軌跡（目標軌道）は、直線軌道を表す関数（一次関数）によって与えられてもよく、さらに、曲線軌道と直線軌道との組み合わせを表す関数によって与えられてもよい。 On the other hand, when the target trajectory shown in FIG. 6 is set as in the present embodiment, even before the blade target position xref is set, the blade load f follows an increasing process close to the target trajectory. While approaching the first load threshold f1, the blade 4 enters the ground at an appropriate descent speed, and the blade 4 enters the ground at a depth when the blade load f reaches the first load threshold f1. The increase can be suppressed. Thus, the change in the amount of soil on the blade 4 with respect to the travel distance of the excavator 1 is small, and the fluctuation of the blade load f is also small. As a result, the effect of suppressing undulation on the construction surface can be further enhanced. The target trajectory (target trajectory) may be any as long as the blade load f can be controlled so that the blade load f gradually approaches the first load threshold f1 as described above. Is not particularly limited. The target trajectory (target trajectory) may be given, for example, by a function representing a curved trajectory such that the blade load f gradually approaches the first load threshold f1 as shown by a chain line in FIG. The target trajectory (target trajectory) may be given by a function (linear function) representing a straight trajectory, or may be given by a function representing a combination of a curved trajectory and a straight trajectory.
　そして、本実施形態では、ブレード負荷ｆが前記目標軌跡に近い増加プロセスをたどりながら前記第１負荷閾値ｆ１に近づいて、これらの偏差である前記負荷偏差が十分に小さくなるという条件が満たされると、前記目標位置設定部１４により前記ブレード目標位置ｘｒｅｆが設定される。本実施形態では、当該条件は、ブレード負荷ｆが第１負荷閾値ｆ１に到達すること、より具体的には、これらの偏差（ｆ－ｆ１）である負荷偏差が負の値から正の値になるという条件である。本実施形態では、前記目標位置設定部１４により設定される前記ブレード目標位置ｘｒｅｆは、前記条件が満たされたときの前記ブレード位置ｘを通り前記目標設計面に平行な平面上の位置に設定される。当該ブレード目標位置ｘｒｅｆが設定された後には、前記ブレード動作制御部１５は、前記ブレード位置ｘと前記ブレード目標位置ｘｒｅｆとの位置偏差Δｘがゼロに近づくようにブレード４の昇降動作を制御する。 In the present embodiment, when the condition that the blade load f approaches the first load threshold value f1 while following the increasing process close to the target trajectory, and the load deviation, which is the deviation thereof, is sufficiently reduced is satisfied. The target position setting section 14 sets the blade target position xref. In the present embodiment, the condition is that the blade load f reaches the first load threshold value f1, and more specifically, the load deviation, which is the deviation (f−f1), changes from a negative value to a positive value. Condition. In the present embodiment, the blade target position xref set by the target position setting unit 14 is set to a position on a plane parallel to the target design plane, passing through the blade position x when the condition is satisfied. You. After the target blade position xref is set, the blade operation control unit 15 controls the raising / lowering operation of the blade 4 so that the positional deviation Δx between the blade position x and the target blade position xref approaches zero.
　次に、コントローラ１０は、前記ブレード負荷取得部３４により取得された前記ブレード負荷ｆと予め設定された閾値であるフラグ閾値との比較をする（ステップＳ５）。本実施形態では、前記フラグ閾値は、第２負荷閾値ｆ２と同じであるが、これに限られず、第２負荷閾値ｆ２と異なるものであってもよい。ただし、フラグ閾値は、第１負荷閾値ｆ１よりも大きな値に設定される。 Next, the controller 10 compares the blade load f acquired by the blade load acquisition unit 34 with a flag threshold which is a preset threshold (Step S5). In the present embodiment, the flag threshold is the same as the second load threshold f2, but is not limited thereto, and may be different from the second load threshold f2. However, the flag threshold is set to a value larger than the first load threshold f1.
　前記記憶部１３は、前記ブレード負荷ｆが第２負荷閾値ｆ２（フラグ閾値）よりも大きい場合には（ｆ＞ｆ２、ステップＳ５においてＮＯ）、前記ブレード目標位置ｘｒｅｆの更新を許容することを示す第１状態（更新フラグ＝１）を記憶する（ステップＳ６）。一方、ブレード負荷ｆが第２負荷閾値ｆ２（フラグ閾値）以下である場合には（ｆ≦ｆ２、ステップＳ５においてＹＥＳ）、更新フラグの記憶の変更は行われない。 When the blade load f is larger than the second load threshold f2 (flag threshold) (f> f2, NO in step S5), the storage unit 13 indicates that the update of the blade target position xref is permitted. The first state (update flag = 1) is stored (step S6). On the other hand, when the blade load f is equal to or less than the second load threshold f2 (flag threshold) (f ≦ f2, YES in step S5), the storage of the update flag is not changed.
　次に、コントローラ１０は、第１状態が記憶部１３に記憶されていること（更新フラグ＝１）と、ブレード負荷ｆが第１負荷閾値ｆ１に到達することとを含む条件（更新条件）が満たされるか否かを判定する（ステップＳ７）。具体的には、本実施形態では、コントローラ１０は、第１状態が記憶部１３に記憶されていること（更新フラグ＝１）である第１条件と、ブレード負荷取得部３４により今回取得されたブレード負荷ｆが第１負荷閾値ｆ１よりも大きいこと（ｆ＞ｆ１）である第２条件と、ブレード負荷取得部３４により前回取得されたブレード負荷ｆが第１負荷閾値ｆ１よりも小さいこと（ｆ＜ｆ１）である第３条件とを含む更新条件が満たされるか否かを判定する（ステップＳ７）。 Next, the controller 10 sets a condition (update condition) including that the first state is stored in the storage unit 13 (update flag = 1) and that the blade load f reaches the first load threshold f1. It is determined whether or not the condition is satisfied (step S7). Specifically, in the present embodiment, the controller 10 determines that the first condition is that the first state is stored in the storage unit 13 (update flag = 1), and that the controller 10 has acquired the first condition this time. The second condition that the blade load f is larger than the first load threshold f1 (f> f1), and that the blade load f previously obtained by the blade load obtaining unit 34 is smaller than the first load threshold f1 (f It is determined whether or not an update condition including the third condition of <f1) is satisfied (step S7).
　当該更新条件が満たされている場合（ステップＳ７においてＹＥＳ）、目標位置設定部１４は、ブレード目標位置ｘｒｅｆを更新する（ステップＳ８）。本実施形態では、前記目標位置設定部１４により更新される前記ブレード目標位置ｘｒｅｆは、前記更新条件が満たされたときの前記ブレード位置ｘを通り前記目標設計面に平行な平面上の位置に設定される。当該ブレード目標位置ｘｒｅｆが更新されると、記憶部１３は、前記ブレード目標位置ｘｒｅｆの更新を許容しないことを示す第２状態（更新フラグ＝０）を前記第１状態に代えて記憶する（ステップＳ８）。 If the update condition is satisfied (YES in step S7), the target position setting unit 14 updates the blade target position xref (step S8). In the present embodiment, the blade target position xref updated by the target position setting unit 14 is set to a position on a plane that passes through the blade position x and is parallel to the target design plane when the update condition is satisfied. Is done. When the blade target position xref is updated, the storage unit 13 stores a second state (update flag = 0) indicating that the update of the blade target position xref is not permitted, in place of the first state (step). S8).
　ステップＳ５～Ｓ８の処理を、図７を参照してより具体的に説明する。図７は、前記ブレード制御装置１００において、ブレード負荷ｆに基づいて更新されるブレード目標位置ｘｒｅｆについて説明するためのタイムチャートの一例である。 処理 The processing of steps S5 to S8 will be described more specifically with reference to FIG. FIG. 7 is an example of a time chart for describing the blade target position xref updated in the blade control device 100 based on the blade load f.
　図７に示す時間ｔ１及びｔ２においては、前記更新条件のうちの前記第２条件及び第３条件が満たされている。しかし、時間ｔ１及びｔ２においては、記憶部１３は前記ブレード目標位置ｘｒｅｆの更新を許容しないことを示す第２状態（更新フラグ＝０）を記憶しているので、前記更新条件のうちの第１条件が満たされていない。したがって、時間ｔ１及びｔ２においては、前記更新条件が満たされていないので（ステップＳ７においてＮＯ）、目標位置設定部１４は、ブレード目標位置ｘｒｅｆを更新しない。 に お い て At times t1 and t2 shown in FIG. 7, the second condition and the third condition among the update conditions are satisfied. However, at times t1 and t2, the storage unit 13 stores the second state (update flag = 0) indicating that the update of the blade target position xref is not allowed. The condition has not been met. Therefore, at times t1 and t2, the update condition is not satisfied (NO in step S7), so that the target position setting unit 14 does not update the blade target position xref.
　一方、図７に示す時間ｔ３において、前記ブレード負荷ｆが第２負荷閾値ｆ２（フラグ閾値）よりも大きくなり、記憶部１３が第１状態（更新フラグ＝１）を記憶しているので（ステップＳ６）、時間ｔ４においては、前記更新条件のすべてが満たされている（ステップＳ７においてＹＥＳ）。したがって、時間ｔ４においては、目標位置設定部１４は、ブレード目標位置ｘｒｅｆを更新する。 On the other hand, at time t3 shown in FIG. 7, the blade load f becomes larger than the second load threshold f2 (flag threshold), and the storage unit 13 stores the first state (update flag = 1) (step S3). S6) At time t4, all of the update conditions are satisfied (YES in step S7). Therefore, at time t4, the target position setting unit 14 updates the blade target position xref.
　なお、ブレード目標位置ｘｒｅｆの更新は、図７に示す態様に限られない。図８は、ブレード負荷ｆに基づいて更新されるブレード目標位置ｘｒｅｆについて説明するためのタイムチャートの他の例である。図８に示す態様では、更新条件は、前記第１条件、前記第２条件及び前記第３条件のうち、第１条件を含まず、第２条件及び第３条件を含む。図８に示す態様では、更新条件が満たされる時間、すなわち前記第２条件及び前記第３条件が満たされる時間ｔ１，ｔ２，ｔ４のそれぞれにおいて、目標位置設定部１４は、ブレード目標位置ｘｒｅｆを更新する。 The update of the blade target position xref is not limited to the mode shown in FIG. FIG. 8 is another example of a time chart for explaining the blade target position xref updated based on the blade load f. In the mode illustrated in FIG. 8, the update condition does not include the first condition, but includes the second condition and the third condition among the first condition, the second condition, and the third condition. In the mode shown in FIG. 8, the target position setting unit 14 updates the blade target position xref at times when the update condition is satisfied, that is, at times t1, t2, and t4 when the second condition and the third condition are satisfied. I do.
　図７に示す態様では、ブレード目標位置ｘｒｅｆの更新フラグが第１状態（更新フラグ＝１）にあるときにブレード目標位置ｘｒｅｆの更新が許容される一方で、前記更新フラグが第２状態（更新フラグ＝０）にあるときにはブレード目標位置ｘｒｅｆの更新が許容されないので、ブレード目標位置ｘｒｅｆが頻繁に更新されるのを抑制できる。 In the mode shown in FIG. 7, while the update of the blade target position xref is permitted when the update flag of the blade target position xref is in the first state (update flag = 1), the update flag is set in the second state (update). When the flag is at (0), the update of the blade target position xref is not allowed, so that the frequent update of the blade target position xref can be suppressed.
　次に、前記ブレード動作制御部１５は、リフトシリンダ８の動作を制御するための前記リフトシリンダ制御用比例弁４１への指令値を演算する（ステップＳ９）。ブレード動作制御部１５は、当該指令値が予め設定された上限値以下であるか否かを判定する（ステップＳ１０）。当該指令値が予め設定された上限値以下である場合には（ステップＳ１０においてＹＥＳ）、ブレード動作制御部１５は前記指令値を出力し、出力された当該指令値は、比例弁４１（図２参照）に入力され、当該制御が適用される（ステップＳ１２）。一方、当該指令値が予め設定された上限値より大きい場合には（ステップＳ１０においてＮＯ）、ブレード動作制御部１５は、前記上限値にカットオフされたものを指令値とし（ステップＳ１１）、このカットオフされた指令値を出力し、出力された当該指令値は、比例弁４１（図２参照）に入力され、当該制御が適用される（ステップＳ１２）。 Next, the blade operation control unit 15 calculates a command value to the lift cylinder control proportional valve 41 for controlling the operation of the lift cylinder 8 (Step S9). The blade operation control unit 15 determines whether the command value is equal to or less than a preset upper limit value (Step S10). If the command value is equal to or less than the preset upper limit value (YES in step S10), blade operation control section 15 outputs the command value, and the output command value is output to proportional valve 41 (FIG. 2). ), And the control is applied (step S12). On the other hand, if the command value is larger than the preset upper limit value (NO in step S10), the blade operation control unit 15 sets the value cut off to the upper limit value as a command value (step S11). The command value that has been cut off is output, and the output command value is input to the proportional valve 41 (see FIG. 2), and the control is applied (step S12).
　本実施形態では、ステップＳ９においてブレード動作制御部１５により演算される当該指令値は、例えば次の式（１）に表される関数に基づいて演算される。 In the present embodiment, the command value calculated by the blade operation control unit 15 in step S9 is calculated based on, for example, a function represented by the following equation (1).
　指令値＝ｋｘ（Δｘ）×Δｘ＋ｋｆ（Δｆ）×Δｆ　　・・・（１）
　上記の式（１）に表される前記関数は、前記ブレード位置ｘと前記ブレード目標位置ｘｒｅｆとの高低差である位置偏差Δｘを変数として含むとともに当該位置偏差Δｘに乗じる位置ゲインｋｘを含む項と、前記ブレード負荷ｆから前記第２負荷閾値ｆ２を引き算することにより得られる偏差（ｆ－ｆ２）である負荷偏差Δｆを変数として含むとともに当該負荷偏差に乗じる負荷ゲインｋｆを含む項を有する。 Command value = kx (Δx) × Δx + kf (Δf) × Δf (1)
The function represented by the above equation (1) includes, as a variable, a position deviation Δx that is a height difference between the blade position x and the blade target position xref, and a position gain kx multiplied by the position deviation Δx. And a term including a load deviation Δf which is a deviation (ff−2) obtained by subtracting the second load threshold f2 from the blade load f as a variable, and including a load gain kf by which the load deviation is multiplied.
　図９は、前記ブレード制御装置１００において、機械本体の車***置と目標設計面との距離に基づいて第１負荷閾値ｆ１を更新することを説明するための概略図であり、図１０は、その説明のためのグラフである。 FIG. 9 is a schematic diagram for explaining updating the first load threshold value f1 based on the distance between the vehicle body position of the machine main body and the target design surface in the blade control device 100. FIG. It is a graph for explanation.
　図９及び図１０に示すように、前記負荷閾値設定部１６は、前記車***置取得部３１により取得される前記車***置と前記目標設計面との距離である本体距離Ｚが第１距離Ｚ１であるときよりも、前記本体距離Ｚが前記第１距離Ｚ１よりも小さい第２距離Ｚ２であるときの方が、前記第１負荷閾値ｆ１が小さくなるように前記第１負荷閾値ｆ１を更新するように構成されている。前記距離演算部１９は、前記目標設計面と前記車***置とに基づいて前記本体距離Ｚを演算する。 As shown in FIGS. 9 and 10, the load threshold setting unit 16 determines that the main body distance Z, which is the distance between the vehicle body position acquired by the vehicle body position acquisition unit 31 and the target design plane, is a first distance Z1. When the main body distance Z is the second distance Z2 smaller than the first distance Z1, the first load threshold f1 is updated so that the first load threshold f1 is smaller than when there is a certain distance. Is configured. The distance calculation unit 19 calculates the main body distance Z based on the target design surface and the vehicle body position.
　このような本実施形態では、前記本体距離Ｚが前記第２距離Ｚ２である場合（すなわち、前記機械本体が前記目標設計面に近い場合）には、前記本体距離Ｚが前記第１距離Ｚ１である場合（すなわち、前記機械本体が前記目標設計面から遠い場合）に比べて、前記ブレード負荷ｆが前記第１負荷閾値ｆ１に到達しやすくなる。図９の具体例では、第２距離Ｚ２が第１距離Ｚ１よりも小さいので、前者の場合の車***置とブレード目標位置ｘｒｅｆとの距離ΔＺ２は、後者の場合の車***置とブレード目標位置ｘｒｅｆとの距離ΔＺ１よりも小さくなっている。この態様は、前記ブレード目標位置ｘｒｅｆの更新頻度を高め、ブレード目標位置ｘｒｅｆが掘削対象の地面の状態に対応してより適正な位置に設定される可能性を高める。 In this embodiment, when the main body distance Z is the second distance Z2 (that is, when the machine main body is close to the target design surface), the main body distance Z is equal to the first distance Z1. The blade load f is more likely to reach the first load threshold f1 than in a certain case (that is, when the machine body is far from the target design surface). In the specific example of FIG. 9, since the second distance Z2 is smaller than the first distance Z1, the distance ΔZ2 between the vehicle body position in the former case and the blade target position xref is equal to the vehicle body position and the blade target position xref in the latter case. Is smaller than the distance ΔZ1. In this aspect, the frequency of updating the blade target position xref is increased, and the possibility that the blade target position xref is set to a more appropriate position corresponding to the state of the ground to be excavated is increased.
　本態様の具体例としては次のようなものが挙げられる。例えば、油圧ショベル１による作業の最終段階における整地動作が行われるときの前記第１負荷閾値ｆ１が、前記作業の初期段階や中間段階における掘削動作が行われるときの前記第１負荷閾値ｆ１よりも小さい値に設定される。かかる場合には、整地動作に比べて迅速な掘削作業が重視される掘削動作と、施工面を目標設計面に近づける精度が重視される整地動作の両方が、同様の制御アルゴリズムを用いて実施可能になる。 具体 Specific examples of the present embodiment include the following. For example, the first load threshold f1 when the ground leveling operation is performed in the final stage of the operation by the excavator 1 is larger than the first load threshold f1 when the excavation operation is performed in the initial stage or the intermediate stage of the operation. Set to a small value. In such a case, the same control algorithm can be used for both the excavation operation where quick excavation work is more important than the leveling operation and the leveling operation where emphasis is placed on the accuracy of bringing the construction surface closer to the target design surface. become.
　本実施形態では、図１０に示されているように、負荷閾値設定部１６は、前記本体距離Ｚの全範囲のうち、前記第１距離Ｚ１及び前記第２距離Ｚ２を含む一部の範囲において、前記本体距離Ｚが小さくなるにつれて第１負荷閾値ｆ１が小さくなるように第１負荷閾値ｆ１を更新する。そして、負荷閾値設定部１６は、前記本体距離Ｚが前記一部の範囲より大きい範囲と、前記本体距離Ｚが前記一部の範囲より小さい範囲とにおいては、第１負荷閾値ｆ１を更新しない。ただし、第１負荷閾値ｆ１の更新は、図１０に示される具体例に限定されない。 In the present embodiment, as shown in FIG. 10, the load threshold value setting unit 16 sets the load threshold value in a part of the entire range of the main body distance Z including the first distance Z1 and the second distance Z2. The first load threshold f1 is updated so that the first load threshold f1 decreases as the body distance Z decreases. Then, the load threshold setting unit 16 does not update the first load threshold f1 in a range where the body distance Z is larger than the partial range and in a range where the body distance Z is smaller than the partial range. However, the update of the first load threshold f1 is not limited to the specific example shown in FIG.
　図１１は、前記ブレード制御装置１００において、ブレード位置ｘとブレード目標位置ｘｒｅｆとの偏差（ｘ－ｘｒｅｆ）である位置偏差Δｘに基づいて位置ゲインｋｘを更新することを説明するためのグラフである。 FIG. 11 is a graph for explaining that the blade control device 100 updates the position gain kx based on the position deviation Δx which is the deviation (x−xref) between the blade position x and the blade target position xref. .
　図１１に示すように、前記位置ゲイン設定部１７は、前記ブレード位置ｘが前記ブレード目標位置ｘｒｅｆよりも下方にある場合に前記位置偏差Δｘに基づいて前記ブレード４の上昇速度が高まるように前記位置ゲインｋｘを更新する。この態様では、ブレード位置ｘがブレード目標位置ｘｒｅｆよりも下方にある場合にブレード４の上昇速度が高められるので、掘削対象の地面がブレード目標位置ｘｒｅｆよりも下方に掘削されることを抑制する効果がより高められ、その結果、当該地面が目標設計面よりも下方に掘削されることを抑制する効果がより高められる。 As shown in FIG. 11, when the blade position x is lower than the blade target position xref, the position gain setting unit 17 sets the position gain Δ such that the rising speed of the blade 4 is increased based on the position deviation Δx. Update the position gain kx. In this aspect, when the blade position x is below the blade target position xref, the rising speed of the blade 4 is increased, so that the ground to be excavated is prevented from being excavated below the blade target position xref. As a result, the effect of suppressing the ground from being excavated below the target design surface is further increased.
　また、ブレード動作制御部１５は、ブレード負荷ｆが第２負荷閾値ｆ２よりも大きい場合には（ステップＳ５においてＹＥＳ）、前記ブレード４を上昇させるための指令値を出力する。図１２は、前記ブレード制御装置１００において、ブレード負荷ｆと第２負荷閾値ｆ２との偏差Δｆに基づいて負荷ゲインｋｆを更新することを説明するためのグラフである。 If the blade load f is larger than the second load threshold f2 (YES in step S5), the blade operation controller 15 outputs a command value for raising the blade 4 (step S5). FIG. 12 is a graph for explaining that the blade controller 100 updates the load gain kf based on the deviation Δf between the blade load f and the second load threshold f2.
　図１２に示すように、前記負荷ゲイン設定部１８は、前記ブレード負荷ｆが前記第２負荷閾値ｆ２よりも大きい場合に前記負荷偏差Δｆに基づいて前記ブレード４の上昇速度が高まるように前記負荷ゲインｋｆを更新する。これにより、ブレード負荷ｆが第２負荷閾値ｆ２よりも大きい場合にブレード４の上昇速度が高められるので、ブレード負荷ｆをより迅速に低減し、過大負荷によるスタック等を未然に防止して油圧ショベル１の安定した走行を可能にするという効果がより高められる。 As shown in FIG. 12, when the blade load f is larger than the second load threshold f2, the load gain setting unit 18 controls the load so that the rising speed of the blade 4 is increased based on the load deviation Δf. Update the gain kf. As a result, when the blade load f is larger than the second load threshold f2, the rising speed of the blade 4 is increased, so that the blade load f is reduced more quickly, a stack or the like due to an excessive load is prevented, and the hydraulic excavator is prevented. 1, the effect of enabling stable running is further enhanced.
　以上説明した装置によれば、例えば図１３に示すように、従来の油圧ショベル１による施工面に比べて、本実施形態に係るブレード制御装置１００を備えた油圧ショベル１による施工面は、うねりが効果的に抑制される。 According to the device described above, for example, as shown in FIG. 13, the undulating surface of the hydraulic shovel 1 including the blade control device 100 according to the present embodiment has an undulation as compared with the conventional hydraulic shovel 1. Effectively suppressed.
　なお、本発明は以上説明した実施の形態に限定されない。本発明は、例えば次のような態様を包含する。 The present invention is not limited to the embodiment described above. The present invention includes the following embodiments, for example.
　本発明に係るブレード制御装置が適用される作業機械は油圧ショベルに限らない。本発明は、例えばホイールローダ、ブルドーザ、グレーダなどのようにブレードを備える他の作業機械に広く適用されることが可能である。 The work machine to which the blade control device according to the present invention is applied is not limited to a hydraulic shovel. The present invention can be widely applied to other work machines including a blade, such as a wheel loader, a bulldozer, and a grader.
　以上のように、施工面のうねりを効果的に抑制することができるブレード制御装置が提供される。 As described above, a blade control device capable of effectively suppressing undulation on a construction surface is provided.
　提供されるのは、機械本体と前記機械本体に対して昇降可能に取り付けられたブレードとを備えた作業機械に設けられ、前記ブレードの昇降動作を制御するためのブレード制御装置であって、前記ブレードによる掘削対象の目標形状を特定する目標設計面を設定する目標設計面設定部と、前記作業機械に関する位置情報を取得する位置情報取得部と、前記位置情報取得部により取得された前記位置情報に基づいて、グローバル座標系における前記ブレードの位置であるブレード位置を演算するブレード位置演算部と、前記ブレードにかかる負荷であるブレード負荷を取得するブレード負荷取得部と、前記ブレード負荷の閾値である第１負荷閾値及び前記ブレード負荷の閾値であって前記第１負荷閾値よりも大きい第２負荷閾値を記憶する記憶部と、前記ブレード位置の目標となる位置であって前記目標設計面よりも上方の位置であるブレード目標位置を設定する目標位置設定部と、前記ブレード負荷取得部により取得された前記ブレード負荷が前記第２負荷閾値以下の場合には、前記ブレード位置演算部により演算された前記ブレード位置と前記ブレード目標位置との偏差である位置偏差がゼロに近づくように前記ブレードを昇降させるための指令を出力し、前記ブレード負荷取得部により取得された前記ブレード負荷が前記第２負荷閾値よりも大きい場合には、前記ブレードを上昇させるための指令を出力するブレード動作制御部と、を備え、前記目標位置設定部は、前記ブレード負荷と前記第１負荷閾値とを関連づけて予め設定された更新条件が満たされた場合に、当該更新条件が満たされたときの前記ブレード位置を基準にして前記ブレード目標位置を更新する。 Provided is a blade control device provided on a work machine including a machine main body and a blade attached to the machine main body so as to be able to move up and down, and controlling a raising and lowering operation of the blade, A target design surface setting unit that sets a target design surface that specifies a target shape to be excavated by the blade, a position information acquisition unit that acquires position information about the work machine, and the position information that is acquired by the position information acquisition unit. A blade position calculating unit that calculates a blade position that is the position of the blade in a global coordinate system, a blade load obtaining unit that obtains a blade load that is a load applied to the blade, and a threshold value of the blade load. A first load threshold and a second load threshold that is a threshold of the blade load and is larger than the first load threshold. Part, a target position of the blade position, a target position setting unit that sets a blade target position that is a position above the target design surface, the blade load acquired by the blade load acquisition unit is In the case of being equal to or less than the second load threshold, a command for raising and lowering the blade is issued so that a position deviation, which is a deviation between the blade position and the blade target position calculated by the blade position calculator, approaches zero. Output, when the blade load acquired by the blade load acquisition unit is greater than the second load threshold, a blade operation control unit that outputs a command to raise the blade, comprising: The position setting unit associates the blade load with the first load threshold, and when an update condition set in advance is satisfied, the update is performed. Based on the said blade position when matter is met to update the blade target position.
　前記ブレード制御装置は、ブレード負荷が第２負荷閾値よりも大きい場合には、ブレードを上昇させる制御を行うことにより、過大負荷によるスタック等を未然に防止して作業機械の安定した走行を可能にする。その一方で、ブレード負荷が第２負荷閾値以下の場合には、前記ブレード位置と前記ブレード目標位置との前記位置偏差がゼロに近づくように前記ブレードの昇降動作を制御する。このようにブレード負荷が第２負荷閾値以下の場合においても前記位置偏差がゼロに近づくようにブレードの位置制御を行うことは、上述の特許文献２のようにブレード負荷が第２の設定負荷値以下の場合においてもブレード負荷に基づいてブレードの昇降動作が制御される特許文献２に記載の装置に比べて、施工面のうねりを効果的に抑制することを可能にする。そして、このような施工面のうねりの効果的な抑制は、掘削作業の効率を向上させる。 When the blade load is larger than the second load threshold, the blade control device performs control to raise the blade, thereby preventing a stack or the like due to an excessive load, thereby enabling a stable traveling of the work machine. I do. On the other hand, when the blade load is equal to or less than the second load threshold, the controller controls the raising / lowering operation of the blade such that the positional deviation between the blade position and the blade target position approaches zero. In this manner, even when the blade load is equal to or less than the second load threshold, performing position control of the blade so that the position deviation approaches zero, the blade load is controlled to the second set load value as in Patent Document 2 described above. Also in the following cases, it is possible to effectively suppress the undulation of the construction surface as compared with the device described in Patent Document 2 in which the elevating operation of the blade is controlled based on the blade load. And the effective suppression of the undulation of the construction surface improves the efficiency of the excavation work.
　また、前記ブレード制御装置において、前記第１負荷閾値は、作業機械が安定して走行可能な適正なブレード負荷に対応する値に設定される。そして、前記更新条件は、掘削作業中に変動する実際の前記ブレード負荷と、適正なブレード負荷に対応する値である前記第１負荷閾値とを関連づけて予め設定されたものである。そして、前記ブレード目標位置は、前記更新条件が満たされたときのブレード位置を基準にして更新されるので、ブレード負荷が適正なときのブレード位置に関連づけられたものとなる。したがって、掘削作業において前記ブレード目標位置の更新が繰り返されることにより、掘削対象の地面の状態（例えば、土砂の固さ、土砂の種類など）にかかわらず、掘削作業中のブレード負荷が安定しやすくなる。 In the blade control device, the first load threshold is set to a value corresponding to an appropriate blade load at which the work machine can run stably. The update condition is set in advance by associating the actual blade load that fluctuates during the excavation work with the first load threshold value that is a value corresponding to an appropriate blade load. Since the blade target position is updated based on the blade position when the update condition is satisfied, the blade target position is associated with the blade position when the blade load is appropriate. Therefore, by repeatedly updating the blade target position in the excavation work, the blade load during the excavation work is easily stabilized regardless of the state of the ground to be excavated (for example, the hardness of the earth and sand, the type of earth and sand, etc.). Become.
　また、前記ブレード制御装置において、前記第２負荷閾値は、ブレード負荷が過大になってスタック等が発生するという事態の発生を未然に防止するために設定された値であり、前記第１負荷閾値よりも大きい値である。前記ブレード制御装置では、ブレード負荷が第２負荷閾値よりも大きくなった場合には、ブレードを上昇させる制御が行われる。このことは、上述したようにブレード負荷を低減し、過大負荷によるスタック等を未然に防止して作業機械の安定した走行を可能にする。 Further, in the blade control device, the second load threshold is a value set in order to prevent a situation in which a blade load becomes excessive and a stack or the like occurs, and the first load threshold is set. It is a value larger than. In the blade control device, when the blade load becomes larger than the second load threshold, control for raising the blade is performed. This reduces the blade load as described above, and prevents a stack or the like due to an excessive load from occurring, thereby enabling stable running of the work machine.
　以上のことから、前記ブレード制御装置は、施工面のうねりを効果的に抑制することができ、しかも、作業機械の安定した効率のよい掘削動作を可能にする。 From the above, the blade control device can effectively suppress the undulation of the construction surface, and also enables the work machine to perform a stable and efficient excavation operation.
　前記ブレード制御装置において、前記更新条件は、前記第１負荷閾値に前記ブレード負荷が到達するという条件、又は前記ブレード負荷が前記第１負荷閾値に近づいたことを判定するために前記第１負荷閾値に基づいて設定された判定値に前記ブレード負荷が到達するという条件を含むことが好ましい。この態様では、前記ブレード目標位置は、ブレード負荷が前記第１負荷閾値に到達したとき又は近づいたときのブレード位置を基準にして更新されるので、ブレード負荷が適正なときのブレード位置にほぼ一致したものとなる。したがって、掘削作業中のブレード負荷がより安定しやすくなる。 In the blade control device, the update condition may include a condition that the blade load reaches the first load threshold, or the first load threshold for determining that the blade load has approached the first load threshold. It is preferable to include a condition that the blade load reaches a determination value set based on the blade load. In this aspect, the blade target position is updated based on the blade position when the blade load has reached or approached the first load threshold, so that the blade target position substantially matches the blade position when the blade load is appropriate. It will be. Therefore, the blade load during the excavation work is more easily stabilized.
　前記ブレード制御装置において、前記記憶部は、前記ブレード負荷が予め設定された閾値であるフラグ閾値よりも大きくなると前記ブレード目標位置の更新を許容することを示す第１状態を記憶する一方で、前記ブレード目標位置が更新されると前記ブレード目標位置の更新を許容しないことを示す第２状態を前記第１状態に代えて記憶するように構成され、前記更新条件は、前記第１状態が前記記憶部に記憶されているときに、前記第１負荷閾値に前記ブレード負荷が到達するという条件、又は前記第１状態が前記記憶部に記憶されているときに、前記ブレード負荷が前記第１負荷閾値に近づいたことを判定するために前記第１負荷閾値に基づいて設定された判定値に前記ブレード負荷が到達するという条件を含んでいてもよい。この態様では、ブレード目標位置の更新フラグが第１状態にあるときにブレード目標位置の更新が許容される一方で、前記更新フラグが第２状態にあるときにはブレード目標位置の更新が許容されないので、ブレード目標位置が頻繁に更新されるのを抑制できる。 In the blade control device, the storage unit stores a first state indicating that the update of the blade target position is permitted when the blade load becomes larger than a flag threshold value that is a preset threshold value, When the blade target position is updated, a second state indicating that the update of the blade target position is not permitted is stored in place of the first state, and the update condition is that the first state is the storage state. The condition that the blade load reaches the first load threshold when stored in the storage unit, or the condition that the blade load reaches the first load threshold when the first state is stored in the storage unit. A condition that the blade load reaches a determination value set based on the first load threshold value in order to determine that the blade load has approached. In this aspect, while the update of the blade target position is permitted when the update flag of the blade target position is in the first state, the update of the blade target position is not permitted when the update flag is in the second state. Frequent updating of the blade target position can be suppressed.
　前記ブレード制御装置において、前記目標位置設定部により更新される前記ブレード目標位置は、前記更新条件が満たされたときの前記ブレード位置を通り前記目標設計面に平行な平面上の位置に設定されるのが好ましい。この態様では、前記目標設計面に平行な平面上の位置に設定されたブレード目標位置と前記ブレード位置との前記位置偏差がゼロに近づくように前記ブレードの昇降動作が制御されるので、施工面を目標設計面に近づける掘削作業の効率がより向上する。 In the blade control device, the blade target position updated by the target position setting unit is set to a position on a plane passing through the blade position when the update condition is satisfied and parallel to the target design plane. Is preferred. In this aspect, the lifting / lowering operation of the blade is controlled such that the positional deviation between the blade target position and the blade position set at a position on a plane parallel to the target design surface approaches zero. The efficiency of the excavation work to bring the distance closer to the target design surface is further improved.
　前記ブレード制御装置において、前記記憶部は、前記ブレード負荷が増加しながら前記第１負荷閾値に近づくときの前記ブレード負荷の増加プロセスの目標となる目標軌跡を記憶し、前記ブレード動作制御部は、前記目標位置設定部により前記ブレード目標位置が設定される前には、前記ブレード負荷が前記目標軌跡に近い増加プロセスをたどりながら前記第１負荷閾値に近づくように前記ブレードを昇降させるための指令を出力するように構成されていてもよい。この態様のように目標軌跡が設定されている場合には、ブレード目標位置が設定される前の段階においても、ブレード負荷が前記目標軌跡に近い増加プロセスをたどりながら前記第１負荷閾値に近づくので、ブレードが適度な降下速度で地中へ入り込み、ブレード負荷が前記第１負荷閾値に到達するときのブレードの地中への入り込み深さが大きくなるのを抑制できる。これにより、作業機械の走行距離に対するブレード上の土量の変化が小さく、ブレード負荷の変動も小さくなる。その結果、施工面のうねりを抑制する効果をより高めることができる。そして、本態様では、ブレード負荷が前記目標軌跡に近い増加プロセスをたどりながら前記第１負荷閾値に到達し又は近づいて前記更新条件が満たされると、前記目標位置設定部により前記ブレード目標位置が設定される。そして、当該ブレード目標位置が設定された後には、前記ブレード動作制御部は、前記ブレード位置と前記ブレード目標位置との位置偏差がゼロに近づくようにブレードの昇降動作を制御する。 In the blade control device, the storage unit stores a target trajectory that is a target of the blade load increase process when the blade load approaches the first load threshold while increasing, the blade operation control unit includes: Before the blade target position is set by the target position setting unit, a command for raising and lowering the blade so that the blade load approaches the first load threshold while following an increasing process close to the target trajectory is issued. It may be configured to output. When the target trajectory is set as in this aspect, even before the blade target position is set, the blade load approaches the first load threshold while following an increasing process close to the target trajectory. In addition, it is possible to prevent the blade from entering the ground at an appropriate descending speed and increase the depth of the blade entering the ground when the blade load reaches the first load threshold. As a result, the change in the amount of soil on the blade with respect to the travel distance of the work machine is small, and the change in the blade load is also small. As a result, the effect of suppressing undulation on the construction surface can be further enhanced. Then, in this aspect, when the blade load reaches or approaches the first load threshold while following an increasing process close to the target trajectory and the update condition is satisfied, the blade target position is set by the target position setting unit. Is done. Then, after the blade target position is set, the blade operation control unit controls the raising / lowering operation of the blade so that the positional deviation between the blade position and the blade target position approaches zero.
　前記ブレード制御装置は、前記第１負荷閾値を設定する負荷閾値設定部をさらに備え、前記位置情報取得部は、前記機械本体の位置である車***置を取得する車***置取得部を含み、前記負荷閾値設定部は、前記車***置取得部により取得される前記車***置と前記目標設計面との距離である本体距離が第１距離であるときよりも、前記本体距離が前記第１距離よりも小さい第２距離であるときの方が、前記第１負荷閾値が小さくなるように前記第１負荷閾値を更新するように構成されていてもよい。この態様では、前記本体距離が前記第２距離である場合（すなわち、前記機械本体が前記目標設計面に近い場合）には、前記本体距離が前記第１距離である場合（すなわち、前記機械本体が前記目標設計面から遠い場合）に比べて、前記ブレード負荷が前記第１負荷閾値に到達しやすくなる。このことは、前記ブレード目標位置の更新頻度を高め、ブレード目標位置が掘削対象の地面の状態に対応してより適正な位置に設定される可能性を高める。本態様の具体例としては次のようなものが挙げられる。例えば、作業機械による作業の最終段階における整地動作が行われるときの前記第１負荷閾値が、前記作業の初期段階や中間段階における掘削動作が行われるときの前記第１負荷閾値よりも小さい値に設定される。かかる場合には、整地動作に比べて迅速な掘削作業が重視される掘削動作と、施工面を目標設計面に近づける精度が重視される整地動作の両方が、同様の制御アルゴリズムを用いて実施可能になる。 The blade control device further includes a load threshold setting unit that sets the first load threshold, the position information acquisition unit includes a vehicle body position acquisition unit that acquires a vehicle body position that is a position of the machine main body, The threshold setting unit is configured such that the main body distance is smaller than the first distance than when the main body distance that is a distance between the vehicle body position acquired by the vehicle body position acquisition unit and the target design surface is a first distance. The first load threshold may be updated such that the first load threshold becomes smaller when the distance is the second distance. In this aspect, when the main body distance is the second distance (that is, when the machine main body is close to the target design surface), when the main body distance is the first distance (that is, the machine main body) Is far from the target design surface), the blade load more easily reaches the first load threshold. This increases the frequency of updating the blade target position, and increases the possibility that the blade target position is set to a more appropriate position corresponding to the state of the ground to be excavated. The following are specific examples of this embodiment. For example, the first load threshold when the leveling operation is performed in the final stage of the operation by the work machine is set to a value smaller than the first load threshold when the excavation operation is performed in the initial stage or the intermediate stage of the operation. Is set. In such a case, the same control algorithm can be used for both the excavation operation where quick excavation work is more important than the leveling operation and the leveling operation where emphasis is placed on the accuracy of bringing the construction surface closer to the target design surface. become.
　前記ブレード制御装置において、前記ブレード動作制御部は、前記ブレード位置と前記ブレード目標位置との高低差である位置偏差を変数として含むとともに当該位置偏差に乗じる位置ゲインを含む項を有する関数に基づいて前記指令を出力し、前記ブレード制御装置は、前記位置ゲインを設定する位置ゲイン設定部をさらに備え、前記位置ゲイン設定部は、前記ブレード位置が前記ブレード目標位置よりも下方にある場合に前記位置偏差に基づいて前記ブレードの上昇速度が高まるように前記位置ゲインを更新するのが好ましい。この態様では、ブレード位置がブレード目標位置よりも下方にある場合にブレードの上昇速度が高められるので、掘削対象の地面がブレード目標位置よりも下方に掘削されることを抑制する効果がより高められ、その結果、当該地面が目標設計面よりも下方に掘削されることを抑制する効果がより高められる。 In the blade control device, the blade operation control unit includes, as a variable, a position deviation that is a height difference between the blade position and the blade target position, based on a function having a term including a position gain that is multiplied by the position deviation. Outputting the command, the blade control device further includes a position gain setting unit that sets the position gain, wherein the position gain setting unit sets the position when the blade position is lower than the blade target position. Preferably, the position gain is updated such that the rising speed of the blade increases based on the deviation. In this aspect, since the rising speed of the blade is increased when the blade position is below the blade target position, the effect of suppressing the ground to be excavated from being excavated below the blade target position is further enhanced. As a result, the effect of suppressing the ground from being excavated below the target design surface is further enhanced.
　前記ブレード制御装置において、前記関数は、前記ブレード負荷から前記第２負荷閾値を引き算することにより得られる偏差である負荷偏差を変数として含むとともに当該負荷偏差に乗じる負荷ゲインを含む項をさらに有し、前記ブレード制御装置は、前記負荷ゲインを設定する負荷ゲイン設定部をさらに備え、前記負荷ゲイン設定部は、前記ブレード負荷が前記第２負荷閾値よりも大きい場合に前記負荷偏差に基づいて前記ブレードの上昇速度が高まるように前記負荷ゲインを更新するのが好ましい。この態様では、ブレード負荷が第２負荷閾値よりも大きい場合にブレードの上昇速度が高められるので、ブレード負荷をより迅速に低減し、過大負荷によるスタック等を未然に防止して作業機械の安定した走行を可能にするという効果がより高められる。 In the blade control device, the function further includes a term including a load deviation that is a deviation obtained by subtracting the second load threshold from the blade load as a variable and including a load gain by which the load deviation is multiplied. The blade control device further includes a load gain setting unit configured to set the load gain, wherein the load gain setting unit is configured to control the blade based on the load deviation when the blade load is greater than the second load threshold. It is preferable to update the load gain so that the rising speed of the load increases. In this aspect, when the blade load is greater than the second load threshold, the blade ascending speed is increased, so that the blade load is reduced more quickly, a stack or the like due to an excessive load is prevented, and the working machine is stabilized. The effect of enabling traveling can be further enhanced.

Claims (8)

  1. 　機械本体と前記機械本体に対して昇降可能に取り付けられたブレードとを備えた作業機械に設けられ、前記ブレードの昇降動作を制御するためのブレード制御装置であって、
    　前記ブレードによる掘削対象の目標形状を特定する目標設計面を設定する目標設計面設定部と、
    　前記作業機械に関する位置情報を取得する位置情報取得部と、
    　前記位置情報取得部により取得された前記位置情報に基づいて前記ブレードの位置であるブレード位置を演算するブレード位置演算部と、
    　前記ブレードにかかる負荷であるブレード負荷を取得するブレード負荷取得部と、
    　前記ブレード負荷の閾値である第１負荷閾値及び前記ブレード負荷の閾値であって前記第１負荷閾値よりも大きい第２負荷閾値を記憶する記憶部と、
    　前記ブレード位置の目標となる位置であって前記目標設計面よりも上方の位置であるブレード目標位置を設定する目標位置設定部と、
    　前記ブレード負荷取得部により取得された前記ブレード負荷が前記第２負荷閾値以下の場合には、前記ブレード位置演算部により演算された前記ブレード位置と前記ブレード目標位置との偏差である位置偏差がゼロに近づくように前記ブレードを昇降させるための指令を出力し、前記ブレード負荷取得部により取得された前記ブレード負荷が前記第２負荷閾値よりも大きい場合には、前記ブレードを上昇させるための指令を出力するブレード動作制御部と、を備え、
    　前記目標位置設定部は、前記ブレード負荷と前記第１負荷閾値とを関連づけて予め設定された更新条件が満たされた場合に、当該更新条件が満たされたときの前記ブレード位置を基準にして前記ブレード目標位置を更新する、ブレード制御装置。     A blade control device provided in a work machine including a machine main body and a blade that is attached to the machine main body so as to be able to move up and down, and controls a raising and lowering operation of the blade.
    A target design surface setting unit that sets a target design surface that specifies a target shape of the excavation target by the blade,
    A position information acquisition unit that acquires position information about the work machine,
    A blade position calculation unit that calculates a blade position that is a position of the blade based on the position information acquired by the position information acquisition unit,
    A blade load acquisition unit that acquires a blade load that is a load applied to the blade,
    A storage unit that stores a first load threshold value that is a threshold value of the blade load and a second load threshold value that is a threshold value of the blade load and is larger than the first load threshold value;
    A target position setting unit that sets a blade target position that is a target position of the blade position and is a position above the target design surface.
    When the blade load acquired by the blade load acquisition unit is equal to or less than the second load threshold, a position deviation, which is a deviation between the blade position calculated by the blade position calculation unit and the blade target position, is zero. Output a command for raising and lowering the blade so as to approach the, if the blade load acquired by the blade load acquisition unit is greater than the second load threshold, a command to raise the blade Output blade operation control unit,
    The target position setting unit, when an update condition set in advance by associating the blade load and the first load threshold is satisfied, based on the blade position when the update condition is satisfied, A blade controller that updates the blade target position.
  2. 　前記更新条件は、前記第１負荷閾値に前記ブレード負荷が到達するという条件、又は前記ブレード負荷が前記第１負荷閾値に近づいたことを判定するために前記第１負荷閾値に基づいて設定された判定値に前記ブレード負荷が到達するという条件を含む、請求項１に記載のブレード制御装置。 The update condition is set based on the first load threshold to determine whether the blade load reaches the first load threshold or to determine that the blade load has approached the first load threshold. The blade control device according to claim 1, further comprising a condition that the blade load reaches a determination value.
  3. 　前記記憶部は、前記ブレード負荷が予め設定された閾値であるフラグ閾値よりも大きくなると前記ブレード目標位置の更新を許容することを示す第１状態を記憶する一方で、前記ブレード目標位置が更新されると前記ブレード目標位置の更新を許容しないことを示す第２状態を前記第１状態に代えて記憶するように構成され、
    　前記更新条件は、前記第１状態が前記記憶部に記憶されているときに、前記第１負荷閾値に前記ブレード負荷が到達するという条件、又は前記第１状態が前記記憶部に記憶されているときに、前記ブレード負荷が前記第１負荷閾値に近づいたことを判定するために前記第１負荷閾値に基づいて設定された判定値に前記ブレード負荷が到達するという条件を含む、請求項１に記載のブレード制御装置。     The storage unit stores a first state indicating that the update of the blade target position is permitted when the blade load becomes larger than a flag threshold that is a preset threshold, while the blade target position is updated. Then, a second state indicating that the update of the blade target position is not permitted is stored instead of the first state,
    The update condition is a condition that the blade load reaches the first load threshold when the first state is stored in the storage unit, or the first state is stored in the storage unit. The method according to claim 1, further comprising a condition that the blade load reaches a determination value set based on the first load threshold to determine that the blade load has approached the first load threshold. A blade controller as described.
  4. 　前記目標位置設定部により更新される前記ブレード目標位置は、前記更新条件が満たされたときの前記ブレード位置を通り前記目標設計面に平行な平面上の位置に設定される、請求項１～３の何れか１項に記載のブレード制御装置。 The blade target position updated by the target position setting unit is set to a position on a plane parallel to the target design plane passing through the blade position when the update condition is satisfied. The blade control device according to any one of claims 1 to 4.
  5. 　前記記憶部は、前記ブレード負荷が増加しながら前記第１負荷閾値に近づくときの前記ブレード負荷の増加プロセスの目標となる目標軌跡を記憶し、
    　前記ブレード動作制御部は、前記目標位置設定部により前記ブレード目標位置が設定される前には、前記ブレード負荷が前記目標軌跡に近い増加プロセスをたどりながら前記第１負荷閾値に近づくように前記ブレードを昇降させるための指令を出力する、請求項１～４の何れか１項に記載のブレード制御装置。     The storage unit stores a target trajectory that is a target of the blade load increasing process when the blade load approaches the first load threshold while increasing.
    Before the blade target position is set by the target position setting unit, the blade operation control unit controls the blade load so that the blade load approaches the first load threshold while following an increasing process close to the target trajectory. The blade control device according to any one of claims 1 to 4, which outputs a command for raising and lowering the blade.
  6. 　前記第１負荷閾値を設定する負荷閾値設定部をさらに備え、
    　前記位置情報取得部は、前記機械本体の位置である車***置を取得する車***置取得部を含み、
    　前記負荷閾値設定部は、前記車***置取得部により取得される前記車***置と前記目標設計面との距離である本体距離が第１距離であるときよりも、前記本体距離が前記第１距離よりも小さい第２距離であるときの方が、前記第１負荷閾値が小さくなるように前記第１負荷閾値を更新する、請求項１～５の何れか１項に記載のブレード制御装置。     A load threshold setting unit that sets the first load threshold;
    The position information acquisition unit includes a vehicle body position acquisition unit that acquires a vehicle body position that is the position of the machine body,
    The load threshold setting unit is configured such that the main body distance is greater than the first distance than when the main body distance that is a distance between the vehicle body position acquired by the vehicle body position acquisition unit and the target design surface is a first distance. The blade control device according to any one of claims 1 to 5, wherein the first load threshold is updated such that the first load threshold becomes smaller when the second distance is smaller than the first load threshold.
  7. 　前記ブレード動作制御部は、前記ブレード位置と前記ブレード目標位置との高低差である位置偏差を変数として含むとともに当該位置偏差に乗じる位置ゲインを含む項を有する関数に基づいて前記指令を出力し、
    　前記ブレード制御装置は、前記位置ゲインを設定する位置ゲイン設定部をさらに備え、
    　前記位置ゲイン設定部は、前記ブレード位置が前記ブレード目標位置よりも下方にある場合に前記位置偏差に基づいて前記ブレードの上昇速度が高まるように前記位置ゲインを更新する、請求項１～６の何れか１項に記載のブレード制御装置。     The blade operation control unit outputs the command based on a function including a term including a position gain that is a variable including a position deviation that is a height difference between the blade position and the blade target position, and multiplying the position deviation,
    The blade control device further includes a position gain setting unit that sets the position gain,
    7. The position gain setting unit according to claim 1, wherein the position gain setting unit updates the position gain so that a rising speed of the blade is increased based on the position deviation when the blade position is below the blade target position. The blade control device according to claim 1.
  8. 　前記関数は、前記ブレード負荷から前記第２負荷閾値を引き算することにより得られる偏差である負荷偏差を変数として含むとともに当該負荷偏差に乗じる負荷ゲインを含む項をさらに有し、
    　前記ブレード制御装置は、前記負荷ゲインを設定する負荷ゲイン設定部をさらに備え、
    　前記負荷ゲイン設定部は、前記ブレード負荷が前記第２負荷閾値よりも大きい場合に前記負荷偏差に基づいて前記ブレードの上昇速度が高まるように前記負荷ゲインを更新する、請求項７に記載のブレード制御装置。     The function further includes a term including a load gain that is multiplied by the load deviation while including, as a variable, a load deviation that is a deviation obtained by subtracting the second load threshold from the blade load,
    The blade control device further includes a load gain setting unit that sets the load gain,
    The blade according to claim 7, wherein the load gain setting unit updates the load gain so that a rising speed of the blade is increased based on the load deviation when the blade load is larger than the second load threshold. Control device.
PCT/JP2019/031265 2018-08-31 2019-08-07 Blade control device for work machinery WO2020045018A1 (en)

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Application Number Priority Date Filing Date Title
CN201980055037.5A CN112567098A (en) 2018-08-31 2019-08-07 Scraper control device for construction machine
EP19855394.3A EP3828347A1 (en) 2018-08-31 2019-08-07 Blade control device for work machinery
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