Work machine

Abstract

The work machine has a rotating body, a work device, a position detection device that detects position information of the rotating body, a posture detection device that detects information related to a posture of the work machine, and a control device that performs machine control based on a target surface set based on target shape data, the position information of the rotating body, and the information related to the posture of the work machine. The control device, in a case where it becomes impossible for the position detection device to acquire the position information of the rotating body, memorizes, as reference rotation angle information, rotation angle information of the rotating body detected by the posture detection device at that time, prohibits execution of the machine control when the rotating body is located outside a rotation range determined based on the reference rotation angle information, and permits execution of the machine control when the rotating body is located inside the rotation range and when the rotating body is located inside the rotation range again after being located outside the rotation range.

Description

TECHNICAL FIELD

[0001] The present application relates to a work machine. BACKGROUND

[0002] Known is a control system that controls a work machine having a work device provided with a work tool (see Patent Literature 1). The control system described in Patent Literature 1 obtains a position of the work device based on position information detected by a position detection device, and generates target excavation terrain information from information of a target work surface that represents a target shape, and performs excavation control based on the target excavation terrain information, which makes a speed of the work device in a direction in which the work device approaches an excavation object be below a limit speed. In a case where the target excavation terrain information cannot be obtained in the execution of the excavation control, the control system continues the excavation control using the target excavation terrain information from a point in time before the target excavation terrain information became unable to be obtained.

[0003] In addition, the control system described in Patent Literature 1 maintains the target excavation terrain information from a point in time before the target excavation terrain information became unable to be obtained for a predetermined fixed time, and ends the maintenance of the target excavation terrain information and the execution of the excavation control in progress in accordance with the elapse of the fixed time, travel of the work machine, or rotation of a rotating body on which the work device is mounted.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2015 / 181990 SUMMARY

[0007] In the control system described in Patent Literature 1, for example, if the rotating body is rotated when loading excavated material into a dump truck or the like, the maintenance of the target excavation terrain information ends. Thus, a problem arises from this time that the excavation control cannot be performed until the state in which the target excavation terrain information can be obtained is reached, and work efficiency is reduced.

[0008] An object of the present application is to provide a work machine that can suppress reduction in work efficiency.

[0009] The work machine of one embodiment of the present application includes a traveling body, a rotating body rotatably attached to the traveling body, a work device attached to the rotating body, a position detection device that detects position information of the rotating body, a posture detection device that detects information about a posture of the work machine including a rotation angle of the rotating body, and a control device that acquires target shape data, sets a target surface based on the acquired target shape data, the position information of the rotating body, and the information about the posture of the work machine, and performs machine control of the work device based on the target surface. The control device is configured to, in a case where the position information of the rotating body becomes unacquirable by the position detection device, memorize rotation angle information at the time when the position information of the rotating body becomes unacquirable by the position detection device as reference rotation angle information, prohibit execution of the machine control based on the target surface when the rotating body is located outside a rotation range determined based on the reference rotation angle information, and allow execution of the machine control based on the target surface when the rotating body is located inside the rotation range and when the rotating body is located inside the rotation range again after being located outside the rotation range.

[0010] Effect of Invention

[0011] According to the present application, a work machine capable of suppressing reduction in work efficiency can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is a perspective view of a hydraulic excavator which is an embodiment of the present application.

[0013] Figure 2 FIG. 2 is a schematic configuration view of a hydraulic driving device mounted on the hydraulic excavator.

[0014] Figure 3 FIG. 3 is a configuration view of a hydraulic control unit.

[0015] Figure 4 FIG. 4 is a functional block diagram of a controller.

[0016] Figure 5 FIG. 5 is a view showing a coordinate system (excavator reference coordinate system) in the hydraulic excavator.

[0017] Figure 6 FIG. 6 is a view showing an example of a locus of a top end portion of a bucket when the top end portion of the bucket is controlled in accordance with a corrected target velocity vector Vca.

[0018] Figure 7 FIG. 7 is a view showing an example of a horizontal digging action based on machine control.

[0019] Figure 8 FIG. 8 is a view for explaining a function of a target surface setting section.

[0020] Figure 9 is a diagram that explains the contents of the judgment processing of the rotation posture based on the rotation posture judgment section.

[0021] Figure 10A is a diagram that explains the contents of the generation processing of the temporary target surface based on the target surface generation section, and indicates the slope αs of the target surface.

[0022] Figure 10B is a diagram that explains the contents of the generation processing of the temporary target surface based on the target surface generation section, and indicates the temporary target surface Stb.

[0023] Figure 11 is a diagram that indicates the relationship between the perpendicular distance H and the offset amount Hos.

[0024] Figure 12 is a flowchart that indicates the contents of the target surface setting processing performed by the controller.

[0025] Figure 13 is a flowchart that indicates the contents of the temporary target surface generation processing (step S120) of Figure 12 .

[0026] Figure 14 is a diagram that explains the contents of the generation processing of the temporary target surface performed by the controller based on the modified example of the present embodiment. DETAILED DESCRIPTION

[0027] Hereinafter, as a working machine of an embodiment of the present application, a hydraulic excavator will be described with reference to the drawings. Furthermore, in each drawing, the same reference numerals are assigned to the same components, and repeated description will be appropriately omitted.

[0028] Figure 1 is a perspective view of a hydraulic excavator 1 of the present embodiment. As shown in Figure 1 , the hydraulic excavator (working machine) 1 has a vehicle body (machine body) 1A, and a multi-joint type front working device (hereinafter, simply referred to as working device) 1B installed to the vehicle body 1A. The vehicle body 1A has a traveling body 11, and a rotating body 12 rotatably installed to the traveling body 11. The traveling body 11 is traveling driven by a right traveling motor (not shown) and a left traveling motor 3b. The rotating body 12 is rotationally driven by a rotating hydraulic motor 4.

[0029] The working device 1B has a plurality of driven components (8, 9, 10) that are turnably linked, and a plurality of hydraulic cylinders (5, 6, 7) that drive the driven components, and is installed to the rotating body 12. In the present embodiment, three driven components, i.e., a boom 8, a stick 9, and a bucket 10, are serially linked. A base end portion of the boom 8 is linked by a boom pin 91 (refer to Figure 5The stick 9 is rotatably connected. The base end of the stick 9 is connected to the top end of the boom 8 by a stick pin 92 (see reference). Figure 5 The bucket 10, which serves as the working tool, is connected rotatably in the top part of the stick 9 by a bucket pin 93 (see reference). Figure 5 The boom pin 91, stick pin 92, and bucket pin 93 are arranged in parallel to each other, and each driven component (8, 9, 10) is designed to be able to rotate relative to each other in the same plane.

[0030] The boom 8 rotates via the extension and retraction of the boom hydraulic cylinder 5. The stick 9 rotates via the extension and retraction of the stick hydraulic cylinder 6. The bucket 10 rotates via the extension and retraction of the bucket hydraulic cylinder 7. One end of the boom hydraulic cylinder 5 is connected to the boom 8, and the other end is connected to the frame of the rotating body 12. One end of the stick hydraulic cylinder 6 is connected to the stick 9, and the other end is connected to the boom 8. One end of the bucket hydraulic cylinder 7 is connected to the bucket 10 via the bucket connecting rod (connecting rod assembly), and the other end is connected to the stick 9.

[0031] A cab 1C for the operator is located on the front left side of the rotating body 12. The cab 1C is equipped with a right travel lever 13a and a left travel lever 13b for indicating the movement of the traveling body 11, and a right control lever 14a and a left control lever 14b for indicating the movement of the boom 8, stick 9, bucket 10 and rotating body 12.

[0032] An angle sensor 21 is installed on the boom pin 91, which connects the boom 8 to the rotating body 12, to detect the rotation angle of the boom 8 (boom angle α). An angle sensor 22 is installed on the stick pin 92, which connects the stick 9 to the boom 8, to detect the rotation angle of the stick 9 (stick angle β). An angle sensor 23 is installed on the bucket pin 93, which connects the bucket 10 to the stick 9, to detect the rotation angle of the bucket 10 (bucket angle γ). An angle sensor 24 is installed on the rotating body 12, which detects the tilt angle (pitch angle) of the rotating body 12 (vehicle body 1A) in the longitudinal direction relative to a reference plane (e.g., a horizontal plane). The angles of inclination (roll angle ψ) in the left and right directions, and the relative angle (rotation angle θ) of the rotating body 12 with respect to the traveling body 11 in a plane orthogonal to the rotation center axis. The angle signals output from the angle sensors 21 to 24 are sent to the controller 20 (see below). Figure 2 )enter.

[0033] Figure 2 yes Figure 1 The diagram shows a schematic configuration of the hydraulic drive unit 100 mounted on the hydraulic excavator 1. Furthermore, for the sake of simplicity, Figure 2In the figure, only parts related to driving of the boom hydraulic cylinder 5, the stick hydraulic cylinder 6, the bucket hydraulic cylinder 7, and the swing hydraulic motor 4 are shown, and parts related to driving of other hydraulic actuators are omitted.

[0034] As shown in Figure 2 , the hydraulic driving device 100 has: hydraulic actuators (4 to 7); a prime mover 49; a hydraulic pump 2 and a pilot pump 48 driven by the prime mover 49; flow control valves 16a to 16d that control the direction and flow rate of working oil (working fluid) supplied from the hydraulic pump 2 to the hydraulic actuators 4 to 7; hydraulic pilot-operated devices 15A to 15D for operating the flow control valves 16a to 16d; a hydraulic control unit 60; a shuttle valve group 17; and a controller 20 that is a control device for controlling each part of the hydraulic excavator 1.

[0035] The prime mover 49 is a power source of the hydraulic excavator 1, and is constituted by, for example, an internal combustion engine such as a diesel engine. The hydraulic pump 2 has: a swash plate mechanism (not shown) having a pair of input and output ports; and a regulator 18 that adjusts the tilt angle of the swash plate to adjust the discharge capacity (discharge volume). The regulator 18 is operated by a pilot pressure supplied from the shuttle valve group 17 described later.

[0036] The pilot pump 48 is connected to the pilot pressure control valves 52 to 59 and the hydraulic control unit 60 described later via a lock valve 51. The lock valve 51 is opened and closed in correspondence with the operation of a door lock lever (not shown) provided near the entrance of the cab 1C. When the door lock lever is operated to the lowered position (lock release position) that restricts the entrance of the cab 1C, the lock valve 51 is opened by an instruction from the controller 20. Thereby, the discharge pressure (hereinafter referred to as pilot primary pressure) of the pilot pump 48 is supplied to the pilot pressure control valves 52 to 59 and the hydraulic control unit 60, and the operation of the flow control valves 16a to 16d based on the operating devices 15A to 15D becomes possible. On the other hand, when the door lock lever is operated to the raised position (lock position) that opens the entrance of the cab 1C, the lock valve 51 is closed by an instruction from the controller 20. Thereby, the supply of the pilot primary pressure from the pilot pump 48 to the pilot pressure control valves 52 to 59 and the hydraulic control unit 60 is stopped, and the operation of the flow control valves 16a to 16d based on the operating devices 15A to 15D becomes impossible.

[0037] The operating device 15A is an operating device that operates the boom 8 (boom hydraulic cylinder 5), and has a boom operating lever 15a, a boom-raising pilot pressure control valve 52, and a boom-lowering pilot pressure control valve 53. Here, the boom operating lever 15a corresponds to, for example, the right operating lever 14a when operated in the front-rear direction (refer to Figure 1 ).

[0038] The boom-raising pilot pressure control valve 52 reduces the pilot primary pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a boom-raising pilot pressure) corresponding to the lever stroke (hereinafter referred to as an operation amount) of the boom operation lever 15a in the boom-raising direction. The boom-raising pilot pressure output from the boom-raising pilot pressure control valve 52 is guided to the pilot pressure receiving portion of one side (the left side in the drawing) of the boom flow control valve 16a via the hydraulic control unit 60, the shuttle slide valve group 17, and the pilot pipe 529, and drives the boom flow control valve 16a in the right direction in the drawing. Thus, the working oil discharged from the hydraulic pump 2 is supplied to the cylinder bottom side of the boom hydraulic cylinder 5, and the working oil on the piston rod side is discharged to the tank 50, and the boom hydraulic cylinder 5 is elongated.

[0039] The boom-raising pilot pressure control valve 52 reduces the pilot primary pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a boom-raising pilot pressure) corresponding to the lever stroke (hereinafter referred to as an operation amount) of the boom operation lever 15a in the boom-raising direction. The boom-raising pilot pressure output from the boom-raising pilot pressure control valve 52 is guided to the pilot pressure receiving portion of one side (the left side in the drawing) of the boom flow control valve 16a via the hydraulic control unit 60, the shuttle slide valve group 17, and the pilot pipe 529, and drives the boom flow control valve 16a in the right direction in the drawing. Thus, the working oil discharged from the hydraulic pump 2 is supplied to the cylinder bottom side of the boom hydraulic cylinder 5, and the working oil on the piston rod side is discharged to the tank 50, and the boom hydraulic cylinder 5 is elongated.

[0040] The operation device 15B is an operation device that operates the arm 9 (arm hydraulic cylinder 6), and has an arm operation lever 15b, an arm retracting pilot pressure control valve 54, and an arm extending pilot pressure control valve 55. Here, the arm operation lever 15b corresponds to, for example, the left operation lever 14b when operated in the left-right direction (refer to Figure 1 ).

[0041] The boom-raising pilot pressure control valve 52 reduces the pilot primary pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a boom-raising pilot pressure) corresponding to the lever stroke (hereinafter referred to as an operation amount) of the boom operation lever 15a in the boom-raising direction. The boom-raising pilot pressure output from the boom-raising pilot pressure control valve 52 is guided to the pilot pressure receiving portion of one side (the left side in the drawing) of the boom flow control valve 16a via the hydraulic control unit 60, the shuttle slide valve group 17, and the pilot pipe 529, and drives the boom flow control valve 16a in the right direction in the drawing. Thus, the working oil discharged from the hydraulic pump 2 is supplied to the cylinder bottom side of the boom hydraulic cylinder 5, and the working oil on the piston rod side is discharged to the tank 50, and the boom hydraulic cylinder 5 is elongated.

[0042] The boom-releasing pilot pressure control valve 55 reduces the pilot primary pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a boom-releasing pilot pressure) corresponding to the amount of operation of the boom-releasing direction of the boom lever 15b. The boom-releasing pilot pressure output from the boom-releasing pilot pressure control valve 55 is guided to the pilot pressure receiving portion of the other side (the right side in the drawing) of the boom flow control valve 16b via the hydraulic control unit 60, the shuttle slide valve group 17, and the pilot pipe 559, and drives the boom flow control valve 16b in the left direction in the drawing. Thus, the working oil discharged from the hydraulic pump 2 is supplied to the piston rod side of the boom hydraulic cylinder 6, and the working oil on the cylinder bottom side is discharged to the tank 50, and the boom hydraulic cylinder 6 contracts.

[0043] The operation device 15C is an operation device that operates the bucket 10 (bucket hydraulic cylinder 7), and has a bucket lever 15c, a bucket scooping pilot pressure control valve 56, and a bucket unloading pilot pressure control valve 57. Here, the bucket lever 15c corresponds to, for example, the right lever 14a when operated in the left-right direction (refer to FIG. 2). Figure 1 ).

[0044] The bucket scooping pilot pressure control valve 56 reduces the pilot primary pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a bucket scooping pilot pressure) corresponding to the amount of operation of the bucket scooping direction of the bucket lever 15c. The bucket scooping pilot pressure output from the bucket scooping pilot pressure control valve 56 is guided to the pilot pressure receiving portion of one side (the left side in the drawing) of the bucket flow control valve 16c via the hydraulic control unit 60, the shuttle slide valve group 17, and the pilot pipe 569, and drives the bucket flow control valve 16c in the right direction in the drawing. Thus, the working oil discharged from the hydraulic pump 2 is supplied to the cylinder bottom side of the bucket hydraulic cylinder 7, and the working oil on the piston rod side is discharged to the tank 50, and the bucket hydraulic cylinder 7 extends.

[0045] The bucket unloading pilot pressure control valve 57 reduces the pilot primary pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a bucket unloading pilot pressure) corresponding to the amount of operation of the bucket unloading direction of the bucket lever 15c. The bucket unloading pilot pressure output from the bucket unloading pilot pressure control valve 57 is guided to the pilot pressure receiving portion of the other side (the right side in the drawing) of the bucket flow control valve 16c via the hydraulic control unit 60, the shuttle slide valve group 17, and the pilot pipe 579, and drives the bucket flow control valve 16c in the left direction in the drawing. Thus, the working oil discharged from the hydraulic pump 2 is supplied to the piston rod side of the bucket hydraulic cylinder 7, and the working oil on the cylinder bottom side is discharged to the tank 50, and the bucket hydraulic cylinder 7 contracts.

[0046] The operation device 15D has a rotation operation lever 15d, a right rotation pilot pressure control valve 58, and a left rotation pilot pressure control valve 59. Here, the rotation operation lever 15d corresponds to, for example, the left operation lever 14b when operated in the front-rear direction (refer to Figure 1 ).

[0047] The right rotation pilot pressure control valve 58 depressurizes the primary pilot pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a right rotation pilot pressure) corresponding to the amount of operation of the right rotation direction of the rotation operation lever 15d. The right rotation pilot pressure output from the right rotation pilot pressure control valve 58 is guided to the pilot pressure receiving portion of one side (the right side in the drawing) of the rotation flow control valve 16d via the shuttle valve group 17 and the pilot pipe 589, and drives the rotation flow control valve 16d in the left direction in the drawing. Thereby, the working oil discharged from the hydraulic pump 2 flows into the inlet and outlet ports of one side (the right side in the drawing) of the rotary hydraulic motor 4, and the working oil flowing out of the inlet and outlet ports of the other side (the left side in the drawing) is discharged to the tank 50, and the rotary hydraulic motor 4 rotates in one direction (a direction in which the rotary body 12 is right-rotated).

[0048] The left rotation pilot pressure control valve 59 depressurizes the primary pilot pressure supplied via the lock valve 51 and generates a pilot pressure (hereinafter referred to as a left rotation pilot pressure) corresponding to the amount of operation of the left rotation direction of the rotation operation lever 15d. The left rotation pilot pressure output from the left rotation pilot pressure control valve 59 is guided to the pilot pressure receiving portion of the other side (the left side in the drawing) of the rotation flow control valve 16d via the shuttle valve group 17 and the pilot pipe 599, and drives the rotation flow control valve 16d in the right direction in the drawing. Thereby, the working oil discharged from the hydraulic pump 2 flows into the inlet and outlet ports of the other side (the left side in the drawing) of the rotary hydraulic motor 4, and the working oil flowing out of the inlet and outlet ports of one side (the right side in the drawing) is discharged to the tank 50, and the rotary hydraulic motor 4 rotates in the other direction (a direction in which the rotary body 12 is left-rotated).

[0049] The hydraulic control unit 60 is a device for performing mechanical control (MC), corrects the pilot pressures input from the pilot pressure control valves 52 to 57 in accordance with the instructions from the controller 20, and outputs to the shuttle valve group 17. Thereby, the work device IB can be caused to perform a desired action regardless of the lever operation of the operator.

[0050] The shuttle valve group 17 outputs the pilot pressures input from the hydraulic control unit 60 to the pilot pipes 529, 539, 549, 559, 569, and 579. In addition, the shuttle valve group 17 selects the largest pilot pressure among the input pilot pressures and outputs to the regulator 18 of the hydraulic pump 2. Thereby, the discharge flow rate of the hydraulic pump 2 can be controlled in accordance with the amount of operation of the operation levers 15a to 15d.

[0051] Figure 3 is Figure 2 a configuration view of the hydraulic control unit 60.

[0052] As shown in Figure 3 , the hydraulic control unit 60 has a solenoid shut-off valve 61, shuttle valves 522, 534, 564, 574, and solenoid proportional valves 525, 532, 537, 542, 552, 562, 567, 572, 577.

[0053] The inlet port of the solenoid shut-off valve 61 is connected to the outlet port of the lock valve 51 (refer to Figure 2 ). The outlet port of the solenoid shut-off valve 61 is connected to the inlet ports of the solenoid proportional valves 525, 537, 567, 577. The solenoid shut-off valve 61 sets the opening degree to zero when not energized, and sets the opening degree to maximum by current supply from the controller 20. In the case where the mechanical control is set to be effective, the opening degree of the solenoid shut-off valve 61 is set to maximum, and the supply of the pilot primary pressure to the solenoid proportional valves 525, 537, 567, 577 is started. On the other hand, in the case where the mechanical control is set to be ineffective, the opening degree of the solenoid shut-off valve 61 is set to zero, and the supply of the pilot primary pressure to the solenoid proportional valves 525, 537, 567, 577 is stopped.

[0054] The switching of the effectiveness and ineffectiveness of the mechanical control is performed based on an operation signal from an MC switch 26 (refer to Figure 2 ) provided in the cab 1C. The MC switch 26 is, for example, an alternate action type switch provided on the right operation lever 14a or the left operation lever 14b. The controller 20 supplies a control current to the solenoid of the solenoid shut-off valve 61 to set the opening degree of the solenoid shut-off valve 61 to maximum when an operation signal to make the mechanical control effective is input from the MC switch 26. The controller 20 stops the supply of the control current to the solenoid of the solenoid shut-off valve 61 to set the opening degree of the solenoid shut-off valve 61 to zero when an operation signal to make the mechanical control ineffective is input from the MC switch 26.

[0055] The shuttle valve 522 has two inlet ports and one outlet port, and outputs the high-pressure side among the pressures input from the two inlet ports from the outlet port. One inlet port of the shuttle valve 522 is connected to the boom-raising pilot pressure control valve 52 via a pilot pipe 521. The other inlet port of the shuttle valve 522 is connected to the outlet port of the solenoid proportional valve 525 via a pilot pipe 524. The outlet port of the shuttle valve 522 is connected to the shuttle valve group 17 via a pilot pipe 523.

[0056] The inlet port of the electromagnetic proportional valve 525 is connected to the outlet port of the electromagnetic cut valve 61. The outlet port of the electromagnetic proportional valve 525 is connected to the other inlet port of the shuttle slide valve 522 via the pilot pipe 524. The electromagnetic proportional valve 525 sets the opening degree to zero when not energized, and increases the opening degree in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 525 reduces the pilot primary pressure supplied via the electromagnetic cut valve 61 in accordance with the opening degree thereof, and outputs to the pilot pipe 524. Thereby, the boom raising pilot pressure can be supplied to the pilot pipe 523 even in the case where the boom raising pilot pressure is not supplied to the pilot pipe 521 from the boom raising pilot pressure control valve 52. Further, in the case where the mechanical control for the boom raising operation is not executed, the electromagnetic proportional valve 525 is in the non-energized state, and the opening degree of the electromagnetic proportional valve 525 is zero. At this time, the boom raising pilot pressure supplied from the boom raising pilot pressure control valve 52 is guided to the pilot pressure receiving portion of one of the boom flow control valves 16a, and thereby the boom raising operation corresponding to the lever operation of the operator can be performed.

[0057] The shuttle slide valve 534 has two inlet ports and one outlet port, and outputs the high pressure side among the pressures input from the two inlet ports from the outlet port. One inlet port of the shuttle slide valve 534 is connected to the outlet port of the electromagnetic proportional valve 532 via the pilot pipe 533. The other inlet port of the shuttle slide valve 534 is connected to the outlet port of the electromagnetic proportional valve 537 via the pilot pipe 536. The outlet port of the shuttle slide valve 534 is connected to the shuttle slide valve group 17 via the pilot pipe 535.

[0058] The inlet port of the electromagnetic proportional valve 532 is connected to the boom lowering pilot pressure control valve 53 via the pilot pipe 531. The outlet port of the electromagnetic proportional valve 532 is connected to one inlet port of the shuttle slide valve 534 via the pilot pipe 533. The electromagnetic proportional valve 532 sets the opening degree to maximum when not energized, and decreases the opening degree from maximum to zero in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 532 reduces the boom lowering pilot pressure input via the pilot pipe 531 in accordance with the opening degree thereof, and outputs to the pilot pipe 533. Thereby, the boom lowering pilot pressure generated based on the lever operation of the operator can be reduced or set to zero.

[0059] The inlet port of the electromagnetic proportional valve 537 is connected to the outlet port of the electromagnetic cut valve 61, and the outlet port of the electromagnetic proportional valve 537 is connected to the other inlet port of the shuttle slide valve 534 via the pilot pipe 536. The electromagnetic proportional valve 537 sets the opening degree to zero when not energized, and increases the opening degree in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 537 reduces the pilot primary pressure supplied via the electromagnetic cut valve 61 in accordance with the opening degree thereof, and outputs to the pilot pipe 536. Thereby, the boom lowering pilot pressure can be supplied to the pilot pipe 535 even in the case where the boom lowering pilot pressure is not supplied to the pilot pipe 531 from the boom lowering pilot pressure control valve 53. Further, in the case where the mechanical control for the boom lowering operation is not executed, the electromagnetic proportional valves 532, 537 are in the non-energized state, the opening degree of the electromagnetic proportional valve 532 is fully open, and the opening degree of the electromagnetic proportional valve 537 is zero. At this time, the boom lowering pilot pressure supplied from the boom lowering pilot pressure control valve 53 is guided to the other pilot pressure receiving portion of the boom flow control valve 16a, whereby the boom lowering operation corresponding to the lever operation of the operator can be performed.

[0060] The inlet port of the electromagnetic proportional valve 542 is connected to the boom retraction pilot pressure control valve 54 via the pilot pipe 541. The outlet port of the electromagnetic proportional valve 542 is connected to the shuttle slide valve group 17 via the pilot pipe 543. The electromagnetic proportional valve 542 sets the opening degree to maximum when not energized, and decreases the opening degree from maximum to zero in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 542 reduces the boom retraction pilot pressure input via the pilot pipe 541 in accordance with the opening degree thereof, and outputs to the pilot pipe 543. Thereby, the boom retraction pilot pressure generated based on the lever operation of the operator can be reduced or set to zero. Further, in the case where the mechanical control for the boom retraction operation is not executed, the electromagnetic proportional valve 542 is in the non-energized state, and the opening degree of the electromagnetic proportional valve 542 is fully open. At this time, the boom retraction pilot pressure supplied from the boom retraction pilot pressure control valve 54 is guided to one pilot pressure receiving portion of the boom flow control valve 16b, whereby the boom retraction operation corresponding to the lever operation of the operator can be performed.

[0061] The inlet port of the electromagnetic proportional valve 552 is connected to the boom dump pilot pressure control valve 55 via a pilot pipe 551. The outlet port of the electromagnetic proportional valve 552 is connected to the shuttle valve group 17 via a pilot pipe 553. The electromagnetic proportional valve 552 sets the opening degree to maximum when not energized, and decreases the opening degree from maximum to zero in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 552 reduces the boom dump pilot pressure input via the pilot pipe 551 in accordance with the opening degree thereof, and outputs to the pilot pipe 553. Thereby, the boom dump pilot pressure generated based on the lever operation of the operator can be reduced or set to zero. Further, in the case where mechanical control for boom dump operation is not performed, the electromagnetic proportional valve 552 is in a non-energized state, and the opening degree of the electromagnetic proportional valve 552 is fully open. At this time, the boom dump pilot pressure supplied from the boom dump pilot pressure control valve 55 is guided to the other pilot pressure receiving portion of the boom flow control valve 16b, whereby boom dump operation in accordance with the lever operation of the operator can be performed.

[0062] The shuttle valve 564 has two inlet ports and one outlet port, and outputs the high-pressure side among the pressures input from the two inlet ports from the outlet port. One inlet port of the shuttle valve 564 is connected to the outlet port of the electromagnetic proportional valve 562 via a pilot pipe 563. The other inlet port of the shuttle valve 564 is connected to the outlet port of the electromagnetic proportional valve 567 via a pilot pipe 566. The outlet port of the shuttle valve 564 is connected to the shuttle valve group 17 via a pilot pipe 565.

[0063] The inlet port of the electromagnetic proportional valve 562 is connected to the bucket scoop pilot pressure control valve 56 via a pilot pipe 561. The outlet port of the electromagnetic proportional valve 562 is connected to one inlet port of the shuttle valve 564 via a pilot pipe 563. The electromagnetic proportional valve 562 sets the opening degree to maximum when not energized, and decreases the opening degree from maximum to zero in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 562 reduces the bucket scoop pilot pressure input via the pilot pipe 561 in accordance with the opening degree thereof, and outputs to the pilot pipe 563. Thereby, the bucket scoop pilot pressure generated based on the lever operation of the operator can be reduced or set to zero.

[0064] The inlet port of the electromagnetic proportional valve 567 is connected to the outlet port of the electromagnetic cut valve 61, and the outlet port of the electromagnetic proportional valve 567 is connected to the other inlet port of the shuttle slide valve 564 via a pilot pipe 566. The electromagnetic proportional valve 567 sets the opening degree to zero when not energized, and increases the opening degree in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 567 reduces the pilot primary pressure supplied via the electromagnetic cut valve 61 in accordance with the opening degree thereof, and outputs to the pilot pipe 566. Thus, even in the case where the bucket loading pilot pressure is not supplied to the pilot pipe 561 from the bucket loading pilot pressure control valve 56, the bucket loading pilot pressure can be supplied to the pilot pipe 565. Further, in the case where the mechanical control for the bucket loading operation is not executed, the electromagnetic proportional valves 562, 567 are in a non-energized state, the opening degree of the electromagnetic proportional valve 562 is fully open, and the opening degree of the electromagnetic proportional valve 567 is zero. At this time, the bucket loading pilot pressure supplied from the bucket loading pilot pressure control valve 56 is guided to the pilot pressure receiving portion of one side of the bucket flow control valve 16c, whereby the bucket loading operation corresponding to the lever operation of the operator can be performed.

[0065] The shuttle slide valve 574 has two inlet ports and one outlet port, and outputs the high-pressure side among the pressures input from the two inlet ports from the outlet port. One inlet port of the shuttle slide valve 574 is connected to the outlet port of the electromagnetic proportional valve 572 via a pilot pipe 573. The other inlet port of the shuttle slide valve 574 is connected to the outlet port of the electromagnetic proportional valve 577 via a pilot pipe 576. The outlet port of the shuttle slide valve 574 is connected to the shuttle slide valve group 17 via a pilot pipe 575.

[0066] The inlet port of the electromagnetic proportional valve 572 is connected to the bucket unloading pilot pressure control valve 57 via a pilot pipe 571. The outlet port of the electromagnetic proportional valve 572 is connected to one inlet port of the shuttle slide valve 574 via the pilot pipe 573. The electromagnetic proportional valve 572 sets the opening degree to maximum when not energized, and decreases the opening degree from maximum to zero in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 572 reduces the bucket unloading pilot pressure input via the pilot pipe 571 in accordance with the opening degree thereof, and supplies to the pilot pipe 573. Thus, the bucket unloading pilot pressure generated based on the lever operation of the operator can be reduced or set to zero.

[0067] The inlet port of the electromagnetic proportional valve 577 is connected to the outlet port of the electromagnetic cut valve 61. The outlet port of the electromagnetic proportional valve 577 is connected to the other inlet port of the spool valve 574 via the pilot pipe 576. The electromagnetic proportional valve 577 sets the opening degree to zero when not energized, and increases the opening degree in accordance with the current supplied from the controller 20. The electromagnetic proportional valve 577 reduces the pilot primary pressure supplied via the electromagnetic cut valve 61 in accordance with the opening degree thereof, and supplies to the pilot pipe 576. Thus, even in the case where the bucket unloading pilot pressure is not supplied to the pilot pipe 571 from the bucket unloading pilot pressure control valve 57, the bucket unloading pilot pressure can be supplied to the pilot pipe 575. Further, in the case where the mechanical control for the bucket unloading operation is not executed, the electromagnetic proportional valves 572, 577 are in the non-energized state, the opening degree of the electromagnetic proportional valve 572 is fully open, and the opening degree of the electromagnetic proportional valve 577 is zero. At this time, the bucket unloading pilot pressure supplied from the bucket unloading pilot pressure control valve 57 is guided to the other pilot pressure receiving portion of the bucket flow control valve 16c, whereby the bucket unloading operation corresponding to the lever operation of the operator can be performed.

[0068] A pressure sensor 526 that detects the boom raising pilot pressure supplied from the boom raising pilot pressure control valve 52 is provided on the pilot pipe 521. A pressure sensor 538 that detects the boom lowering pilot pressure supplied from the boom lowering pilot pressure control valve 53 is provided on the pilot pipe 531. A pressure sensor 544 that detects the stick retracting pilot pressure supplied from the stick retracting pilot pressure control valve 54 is provided on the pilot pipe 541. A pressure sensor 554 that detects the stick releasing pilot pressure supplied from the stick releasing pilot pressure control valve 55 is provided on the pilot pipe 551. A pressure sensor 568 that detects the bucket scooping pilot pressure supplied from the bucket scooping pilot pressure control valve 56 is provided on the pilot pipe 561. A pressure sensor 578 that detects the bucket unloading pilot pressure supplied from the bucket unloading pilot pressure control valve 57 is provided on the pilot pipe 571. The pilot pressures detected by the pressure sensors 526, 538, 544, 554, 568, 578 are input to the controller 20 as operation signals that indicate the operation directions and operation amounts of the operation devices 15A to 15C.

[0069] As shown in FIG. 2, the controller 20 is composed of a microcomputer having a CPU (Central Processing Unit) 20a as an operation circuit, a ROM (Read Only Memory) 20b as a memory device, a RAM (Random Access Memory) 20c as a memory device, an input interface 20d, and an output interface 20e, and other peripheral circuits. The controller 20 can be composed of one microcomputer, or can be composed of a plurality of microcomputers. Figure 2 As shown in FIG. 2, the controller 20 is composed of a microcomputer having a CPU (Central Processing Unit) 20a as an operation circuit, a ROM (Read Only Memory) 20b as a memory device, a RAM (Random Access Memory) 20c as a memory device, an input interface 20d, and an output interface 20e, and other peripheral circuits. The controller 20 can be composed of one microcomputer, or can be composed of a plurality of microcomputers.

[0070] The ROM 20b is a nonvolatile memory such as an EEPROM, and stores programs capable of performing various kinds of arithmetic operations. That is, the ROM 20b is a storage medium capable of reading programs that realize the functions of the present embodiment. The RAM 20c is a volatile memory, and is a work memory in which data is directly input and output between the CPU 20a. The RAM 20c temporarily stores necessary data during the arithmetic execution of the programs by the CPU 20a. Further, the controller 20 can also have a memory device such as a flash memory, a hard disk drive, and the like.

[0071] The CPU 20 is a processing device that expands and arithmetically executes the programs stored in the ROM 20b in the RAM 20c, and performs prescribed arithmetic processing with respect to signals acquired from the input interface 20d and the ROM 20b and the RAM 20c in accordance with the programs. Signals from the MC switch 26, the posture detection device 35, the target surface setting device 36, the operation detection device 34, the position detection device 42, and the like are input to the input interface 20d.

[0072] The input interface 20d converts the input signals in a manner that enables the arithmetic operation by the CPU 20a. In addition, the output interface 20e generates signals for output corresponding to the results of the arithmetic operation in the CPU 20a, and outputs the signals to the electromagnetic proportional valves 525, 532, 537, 542, 552, 562, 567, 572, 577, the electromagnetic on-off valve 61, the notification device 39, and the like.

[0073] The posture detection device 35 has the angle sensors 21 to 24 (refer to FIG. 2). Figure 1 These angle sensors 21 to 24 detect information related to the posture of the hydraulic excavator 1, and output signals corresponding to the information. That is, the angle sensors 21 to 24 function as posture sensors that detect information related to the posture of the hydraulic excavator 1.

[0074] With respect to the angle sensors 21, 22, 23, potentiometers that acquire the boom angle a, the arm angle β, and the bucket angle γ as information related to the posture of the working device IB and output signals (voltages) corresponding to the acquired angles can be employed.

[0075] With respect to the angle sensor 24, an IMU (Inertial Measurement Unit) that acquires the angular velocities and accelerations of orthogonal 3 axes as information related to the posture of the rotating body 12, and based on the information, arithmetically calculates the roll angle (the inclination angle in the left-right direction of the rotating body 12) ψ, the pitch angle (the inclination angle in the front-rear direction of the rotating body 12) φ, and the rotation angle θ of the rotating body 12, and outputs the results of the calculations (the angles ψ, φ, and θ) can be employed. With respect to the angle sensor 24, an IMU (Inertial Measurement Unit) that acquires the angular velocities and accelerations of orthogonal 3 axes as information related to the posture of the rotating body 12, and based on the information, arithmetically calculates the roll angle (the inclination angle in the left-right direction of the rotating body 12) ψ, the pitch angle (the inclination angle in the front-rear direction of the rotating body 12) φ, and the rotation angle θ of the rotating body 12, and outputs the results of the calculations (the angles ψ, φ, and θ) can be employed. Information related to θ is output to controller 20. Additionally, the angle ψ, representing the attitude of the rotating body 12, is also output. The calculation of θ can also be performed by the controller 20 based on the output signal of the IMU. Additionally, as the angle sensor 24, three sensors can be provided, namely, a sensor for detecting the roll angle ψ, a sensor for detecting the pitch angle, and a sensor for detecting the pitch angle. The sensor and the sensor that detects the rotation angle θ.

[0076] The operation detection device 34 has pressure sensors 526, 538, 544, 554, 568, and 578 (see reference). Figure 3 ).

[0077] The position detection device 42 is used to detect the current position information of the rotating body 12 of the hydraulic excavator 1. For example... Figure 4 As shown, the position detection device 42 includes multiple GNSS (Global Navigation Satellite Systems) antennas (hereinafter referred to as GNSS antennas) 42a and 42b, and a positioning calculation device 42c that calculates the position and orientation of the rotating body 12 in the geographic coordinate system (Earth coordinate system) based on satellite signals (GNSS radio waves) received by the GNSS antennas 42a and 42b from multiple positioning satellites. The GNSS antennas 42a and 42b are located on the upper part of the rotating body 12 at positions separated along the left-right direction of the rotating body 12.

[0078] GNSS antenna 42a receives reference position data from a positioning satellite for its own position calculation. GNSS antenna 42b receives reference position data from a positioning satellite for its own position calculation. GNSS antennas 42a and 42b receive reference position data, for example, at a period of 10 Hz. GNSS antennas 42a and 42b output reference position data to the positioning calculation device 42c whenever they receive reference position data.

[0079] The positioning calculation device 42c calculates the reference position P1 of GNSS antenna 42a and the reference position P2 of GNSS antenna 42b, represented in Earth coordinate system, based on the signals (reference position data) received by GNSS antennas 42a and 42b. The positioning calculation device 42c calculates the baseline vector connecting reference positions P1 and P2. Based on reference positions P1 and P2 and the baseline vector, the positioning calculation device 42c calculates the position and azimuth of the rotating body 12. The azimuth of the rotating body 12 is represented, for example, by the angle of Earth coordinates relative to a reference azimuth (e.g., north). When the positioning calculation device 42c acquires two reference position data from GNSS antennas 42a and 42b at a frequency of, for example, 10 Hz, it calculates the position and azimuth of the rotating body 12 and outputs the results to the controller 20.

[0080] Furthermore, the position of the rotating body 12 can be any position, such as a position on the rotation center axis or a position on the center axis of the boom pin 91. The memory device (e.g., ROM) of the positioning calculation device 42c stores geometric information (dimensional data, etc.) that represents the relationship between the coordinates of the positions of the GNSS antennas 42a and 42b in the vehicle coordinate system and the coordinates of the arbitrarily set position of the rotating body 12. Therefore, the positioning calculation device 42c can calculate the coordinates and orientation of the rotating body 12 in the geographic coordinate system based on two reference positions P1 and P2, the baseline vector, and the aforementioned geometric information.

[0081] The notification device 39 is a device that provides prescribed notifications to the operator based on control signals from the controller 20. The notification device 39 is, for example, a display device such as a liquid crystal display (LCD), which displays prescribed images on a display screen based on display control signals from the controller 20. For example, the notification device 39 displays images on the display screen indicating the driving state of the prime mover 49, the driving state of the traveling body 11, the rotation state of the rotating body 12, and the posture of the working device 1B.

[0082] Figure 2 The controller 20 shown executes mechanical control of the control device 1B based on the target surface St when predefined conditions are met. In this mechanical control, the controller 20 outputs control signals to the hydraulic control unit 60 to actuate the compliant flow control valves 16a, 16b, and 16c. For example, the controller 20 outputs control signals to the solenoid proportional valve 525 (see reference...). Figure 3 The system outputs a control signal to actuate the flow control valve 16a, causing the boom hydraulic cylinder 5 to extend and forcibly perform the boom lifting action. Mechanical controls include, for example, area restriction control (land leveling control) performed when the stick is operated via the operating device 15B, and stop control performed when the stick is not operated but the boom is lowered via the operating device 15A.

[0083] like Figure 7 As shown, controller 20 controls at least one of the hydraulic actuators (5, 6, 7) to position the top of bucket 10 (e.g., claw tip) at or above a predetermined target surface St. In area restriction control, the operation of the working device 1B is controlled by moving the top of bucket 10 along the target surface St via stick operation. Specifically, when stick operation is performed, controller 20 issues commands to raise or lower the boom in such a way that the velocity vector of the top of bucket 10 in the direction perpendicular to the target surface St becomes zero. With mechanical control enabled via MC switch 26, when the distance between the top of bucket 10 and the target surface St (target surface distance) becomes less than a predetermined distance Ya1 (see reference...)Figure 6 When the distance between the control point and the target surface St is equal to or less than the threshold value, the area restriction control is executed.

[0084] Further, in the present embodiment, although the control point of the work implement 1B used in the machine control is set at the claw tip of the bucket 10 of the hydraulic excavator 1, the control point can be changed to a point other than the claw tip of the bucket 10 as long as it is a point of the top end portion of the work implement 1B. For example, the bottom surface of the bucket 10 or the outermost portion of the bucket link can be set as the control point. A configuration in which a point on the outer surface of the bucket 10 that is closest to the target surface St is appropriately set as the control point can also be adopted. In the machine control, there is "automatic control" in which the action of the work implement 1B is controlled by the controller 20 when the operation devices 15A, 15B, 15C are not operated, and "semi-automatic control" in which the action of the work implement 1B is controlled by the controller 20 only when the operation devices 15A, 15B, 15C are operated. Further, the semi-automatic control is also referred to as "intervention control" because the control based on the controller 20 is intervened in the operation based on the operator.

[0085] Figure 4 is a functional block diagram of the controller 20. Figure 2 is a functional block diagram of the controller 20.

[0086] As shown in Figure 4 , the controller 20 functions as the posture calculation section 30, the target surface setting section 37, the target action calculation section 32, and the solenoid valve control section 33 by executing the program stored in the ROM 20b. Figure 4 The solenoid proportional valve 500 shown in Figure 3 represents the solenoid proportional valves 525, 532, 537, 542, 552, 562, 567, 572, 577 (see ).

[0087] The posture calculation section 30 calculates the posture of the hydraulic excavator 1 (the posture of the work implement 1B and the rotating body 12) based on the posture information from the posture detection device 35. The posture calculation section 30 calculates the position (hereinafter referred to as the top end position) Pb of the top end portion of the bucket 10 (for example, the claw tip of the bucket 10) in the local coordinate system (the excavator reference coordinate system) based on the posture information from the posture detection device 35 and the geometric information (for example, the lengths LI, L2, L3 of the driven members shown in Figure 5 ).

[0088] The posture of the work implement 1B can be defined based on the excavator reference coordinate system of Figure 5 . Figure 5 is a diagram showing the coordinate system (the excavator reference coordinate system) in the hydraulic excavator 1. Figure 5The excavator reference coordinate system is a coordinate system set with respect to the rotating body 12. In the excavator reference coordinate system, the center axis of the boom pin 91 is set as the origin O, an axis parallel to the center axis of rotation of the rotating body 12 is set as the Y axis, and an axis orthogonal to the Y axis and the boom pin 91 is set as the X axis. The inclination angle of the boom 8 with respect to the X axis is set as the boom angle a, the inclination angle of the stick 9 with respect to the boom 8 is set as the stick angle β, and the inclination angle of the bucket 10 with respect to the stick 9 is set as the bucket angle γ. The inclination angle of the vehicle body 1A (rotating body 12) with respect to the front-rear direction of the horizontal plane (reference plane), that is, the angle of the horizontal plane (reference plane) with respect to the X axis is set as the pitch angle φ.

[0089] The boom angle a is detected by the angle sensor 21, the stick angle β is detected by the angle sensor 22, the bucket angle γ is detected by the angle sensor 23, and the pitch angle φ is detected by the angle sensor 24.

[0090] If the length from the center position of the boom pin 91 to the center position of the stick pin 92 is set as LI, the length from the center position of the stick pin 92 to the center position of the bucket pin 93 is set as L2, and the length from the center position of the bucket pin 93 to the top end portion (toe) of the bucket 10 is set as L3, the top end position Pb of the bucket 10 in the excavator reference coordinate system can be expressed as X bk as the X direction position, and as the Y direction position and expressed by the following equations (1) and (2). bk

[0091] [Equation 1]

[0092] X bk = LI cos a + L2 cos (a + β) + L3 cos (a + β + γ)...(1)

[0093] [Equation 2]

[0094] Y bk = LI sin a + L2 sin (a + β) + L3 sin (a + β + γ)...(2)

[0095] Figure 4 The posture calculation unit 30 shown in the figure calculates the top end position Pb of the bucket 10 in the earth coordinate system based on the top end position Pb of the bucket 10 in the excavator reference coordinate system, the pitch angle φ of the rotating body 12, and the position and orientation of the hydraulic excavator 1 in the earth coordinate system calculated by the position measurement calculation device 42. That is, the posture calculation unit 30 converts the top end position Pb in the excavator reference coordinate system to the top end position Pb in the earth coordinate system.

[0096] ​​Further, the posture operation section 30 calculates, in addition to the top end position Pb of the bucket 10, the positions of the swing boom pin 91, the arm pin 92, and the bucket pin 93 of the working device IB, the origin O in the earth coordinate system, and the like, which indicate the posture of the working device IB, and outputs these pieces of information as the posture information of the hydraulic excavator 1 to the target surface setting section 37 and the target action operation section 32. Further, the posture operation section 30 outputs, in addition to the operation results, the angle information (a, β, γ, θ, ψ) detected by the posture detection device 35 as the posture information to the target surface setting section 37 and the target action operation section 32.

[0097] The target surface setting device 36 is a device for inputting the target shape data used for setting the target surface St used in the machine control to the controller 20. The target surface setting device 36 has a memory device that memorizes the three-dimensional target shape data defined on the earth coordinate system (absolute coordinate system). The target surface setting section 37 acquires the three-dimensional target shape data from the target surface setting device 36, and sets the target surface St based on the acquired target shape data and the posture information (information indicating the posture of the hydraulic excavator 1 in the earth coordinate system) from the posture operation section 30. The target surface setting section 37 generates the cross-sectional shape obtained by cutting the plane (the action plane (X-Y plane) of the working device IB) on which the target shape data is moved by the working device IB as a two-dimensional target surface.

[0098] The target action operation section 32 operates the target action of the working device IB in such a manner that the bucket 10 does not intrude into the target surface St based on the information from the posture operation section 30, the target surface setting section 37, and the operation detection device 34.

[0099] Specifically, the target action operation section 32 operates the target speed of each hydraulic cylinder (5, 6, 7) based on the target surface St set by the target surface setting section 37, the operation results (posture information) of the posture operation section 30, and the detection results (operation information) of the operation detection device 34. The target action operation section 32 operates the target speed of each hydraulic cylinder (5, 6, 7) in such a manner that the working device IB does not dig the lower side of the target surface St in the machine control. Hereinafter, this will be described in detail with reference to Figure 6 . Figure 6 is a drawing showing an example of the locus of the top end portion of the bucket 10 when the top end portion of the bucket 10 is controlled in accordance with the corrected target speed vector Vca. In the description here, as shown in Figure 6 , the Xt axis and the Yt axis are set. The Xt axis is an axis parallel to the target surface St, and the Yt axis is an axis orthogonal to the target surface St.

[0100] The target operation calculation portion 32 calculates the target speed (primary target speed) of each hydraulic cylinder (5, 6, 7) based on the operation amount of the operation devices 15A, 15B, 15C. Then, the target operation calculation portion 32 calculates the target speed vector Vca0 of the top end portion of the bucket 10 based on the target speed (primary target speed) of each hydraulic cylinder (5, 6, 7), the posture information of the hydraulic excavator 1 including the top end position Pb of the bucket 10 calculated by the posture calculation portion 30, and the dimensions (L1, L2, L3, etc.) of each portion of the working device IB memorized in the ROM 20b. In addition, the target operation calculation portion 32 calculates the distance in the Yt-axis direction (target surface distance) between the top end position Pb of the bucket 10 calculated by the posture calculation portion 30 and the target surface St set by the target surface setting portion 37.

[0101] The target operation calculation portion 32 corrects the primary target speed of the necessary hydraulic cylinder among the hydraulic cylinders (5, 6, 7) in such a manner that the target surface distance approaches 0 (zero) and the component Vcay (speed component in the Yt-axis direction) of the target speed vector Vca0 of the top end portion of the bucket 10, which is perpendicular to the target surface St, approaches 0 (zero), and calculates the secondary target speed, thereby performing the control (direction conversion control) that converts the speed vector of the top end portion of the bucket 10 to Vca. The target speed vector Vca when the target surface distance is 0 (zero) has only the component Vcax (speed component in the Xt-axis direction) parallel to the target surface St. Thus, the holding is performed in such a manner that the top end portion (control point) of the bucket 10 is positioned on the target surface St or above it.

[0102] The target operation calculation portion 32, for example, when the operation of retracting the arm alone is performed and the target surface distance becomes the prescribed distance Ya1 or less (that is, when the top end portion of the bucket 10 intrudes into the set region formed by the target surface St and the surface that departs from the target surface St in the Yt-axis direction by Ya1), causes the arm hydraulic cylinder 6 to extend and causes the boom hydraulic cylinder 5 to extend, thereby performing the direction conversion control that converts the speed vector Vca0 to Vca.

[0103] Further, the direction conversion control is sometimes executed by the combination of the boom raising or boom lowering and the arm retraction, and is sometimes executed by the combination of the boom raising or boom lowering and the arm swing-out. In either case, in a state where the top end portion of the bucket 10 is located above the target face St, as long as the target velocity vector Vca includes a downward component (Vcay < 0) approaching the target face St, the target action operation section 32 operates the target velocity of the boom cylinder 5 in the boom raising direction that cancels the downward component. Conversely, when the target velocity vector Vca includes an upward component (Vcay > 0) departing from the target face St, the target action operation section 32 operates the target velocity of the boom cylinder 5 in the boom lowering direction that cancels the upward component. Further, in a state where the top end portion of the bucket 10 is located below the target face St, when the target velocity vector Vca includes an upward component (Vcay > 0) approaching the target face St, the target action operation section 32 operates the target velocity of the boom cylinder 5 in the boom lowering direction that cancels the upward component. Conversely, when the target velocity vector Vca includes a downward component (Vcay < 0) departing from the target face St, the target action operation section 32 operates the target velocity of the boom cylinder 5 in the boom raising direction that cancels the downward component.

[0104] The solenoid valve control section 33 outputs commands with respect to the solenoid cut valve 61 and the solenoid proportional valve 500 on the basis of the operation results (target velocities of the respective hydraulic cylinders) of the target action operation section 32.

[0105] Referring to Figure 7 , an example of the action of the hydraulic excavator 1 when the machine control is executed will be described. Figure 7 is a view showing an example of the horizontal excavating action based on the machine control.

[0106] At the start of the excavating operation, in order to position the bucket 10 at a prescribed position (excavating start point), when the operator performs the boom lowering independent operation based on the operation device 15A, the stop control is executed by the controller 20. The controller 20 controls the solenoid proportional valve 532 (refer to Figure 3 ) so that the velocity of the boom 8 is decelerated in such a manner that the bucket 10 does not intrude below the target face St as the bucket 10 approaches the target face St. The controller 20 controls the solenoid proportional valve 532 (refer to Figure 3 ) so that the velocity of the boom 8 becomes zero in a state where the bucket 10 has reached the target face St.

[0107] When the operator operates the operating device 15B to perform horizontal excavation by the retracting operation (retracting operation) of the arm lever 9 in the arrow A direction, the controller 20 performs the area restriction control. The controller 20 controls the electromagnetic proportional valve 525 (refer to Figure 3 ) in such a manner that the top end portion of the bucket 10 does not intrude below the target surface St, and automatically performs the raising operation of the boom 8. At this time, in order to improve the excavation accuracy, the electromagnetic proportional valve 542 (refer to Figure 3 ) can be controlled to decelerate the speed of the arm lever 9 as necessary. Further, the controller 20 can control the electromagnetic proportional valve 577 (refer to Figure 3 ) to automatically rotate the bucket 10 in the arrow C direction so that the angle B of the bucket 10 with respect to the target surface St becomes a fixed value, and the grading work becomes easy.

[0108] When horizontal excavation is performed by the retracting operation of the arm lever 9 in the arrow A direction, in the case where the bucket 10 intrudes below the target surface St, the controller 20 controls the electromagnetic proportional valve 525 (refer to Figure 3 ) in such a manner that the bucket 10 is returned to the target surface St, and automatically performs the raising operation of the boom 8.

[0109] In this way, the controller 20 controls the operation of the working device IB in such a manner that the top end portion (toe) of the bucket 10 moves along the target surface St.

[0110] However, sometimes the satellite signals (GNSS waves) from the positioning satellites received by the GNSS antennas 42a, 42b become weak due to changes in weather conditions such as being covered by thick cloud layers above the rotating body 12. If the communication conditions of the GNSS antennas 42a, 42b deteriorate, the position and orientation of the rotating body 12 cannot be accurately calculated by the position calculation device 42c. In this case, the position calculation device 42c outputs a position detection error signal to the controller 20. As a result, the controller 20 cannot calculate the operation plane of the working device IB, and cannot update the target surface St based on the current posture information of the hydraulic excavator 1.

[0111] Therefore, in this embodiment, when the communication status of the GNSS antennas 42a and 42b deteriorates during the execution of mechanical control, and the position detection device 42 is unable to obtain the position information of the rotating body 12, the controller 20 remembers the rotation angle information (rotation angle θ) of the rotating body 12 detected by the attitude detection device 35 at this time as the reference rotation angle information (reference rotation angle θ0), and generates a new temporary target surface based on the target surface generated when the communication status is good (normally the target surface). When the rotating body 12 is located outside the rotation range Sr determined based on the reference rotation angle information (reference rotation angle θ0), the controller 20 prohibits the execution of mechanical control based on the temporary target surface. When the rotating body 12 is located inside the rotation range Sr, the controller 20 allows the execution of mechanical control based on the temporary target surface.

[0112] The following is for reference Figures 8 to 13 The control content is described in detail below. This control is from the point where the controller 20 is unable to obtain the position information (position and orientation of the rotating body 12) due to the deterioration of the communication condition until the controller 20 is able to obtain the position information (position and orientation of the rotating body 12) due to the restoration of the communication condition.

[0113] Figure 8 This diagram details the function of the target plane setting unit 37. (For example...) Figure 8 As shown, the target surface setting unit 37 functions as the communication status judgment unit 43, the rotation angle memory unit 44, the rotation posture judgment unit 45, the target surface generation unit 46, and the notification control unit 47.

[0114] The communication status determination unit 43 determines whether the communication status of the GNSS antennas 42a and 42b is good based on the information output from the position detection device 42. In this embodiment, if the communication status determination unit 43 inputs a position detection error signal from the position detection device 42 to the controller 20, it determines that the communication status is not good (that is, information related to the position and orientation of the rotating body 12 cannot be obtained). If the communication status determination unit 43 does not input a position detection error signal to the controller 20, it determines that the communication status is good (that is, information related to the position and orientation of the rotating body 12 can be obtained).

[0115] If the communication status of GNSS antennas 42a and 42b deteriorates, the accuracy of the position and orientation calculations of the rotating body 12 based on the position calculation device 42c of the position detection device 42 will decrease. Therefore, the communication status of GNSS antennas 42a and 42b can be estimated based on the calculation accuracy in the position calculation device 42c.

[0116] The position measurement computing device 42c determines whether the calculation accuracy of the positions of the GNSS antennas 42a, 42b (that is, the position of the rotating body 12) is an allowable accuracy. The position measurement computing device 42c does not output a position detection error signal to the controller 20, but outputs information on the position and orientation of the rotating body 12 that is calculated to the controller 20, in the case where the calculation accuracy of the positions of the GNSS antennas 42a, 42b is an allowable accuracy. The position measurement computing device 42c does not output information on the position and orientation of the rotating body 12 to the controller 20, but outputs a position detection error signal to the controller 20, in the case where the calculation accuracy of the positions of the GNSS antennas 42a, 42b is not an allowable accuracy.

[0117] Further, the method of evaluating the calculation accuracy of the positions of the GNSS antennas 42a, 42b can employ various methods. One example of the method of evaluating the calculation accuracy of the positions of the GNSS antennas 42a, 42b will be described below. The calculation accuracy of the positions of the GNSS antennas 42a, 42b varies depending on the number and arrangement of the positioning satellites from which the GNSS antennas 42a, 42b can receive signals (radio waves). The calculation accuracy of the positions of the GNSS antennas 42a, 42b is affected by the number and arrangement of the positioning satellites, for example, can be represented by DOP (Dilution of Precision). The calculation accuracy of the positions of the GNSS antennas 42a, 42b decreases as the number of positioning satellites decreases and the distance between the positioning satellites becomes narrower. The position measurement computing device 42c calculates a parameter for accuracy evaluation based on information on the number of positioning satellites and the arrangement of the positioning satellites. The parameter for accuracy evaluation is a parameter that increases as the calculation accuracy increases.

[0118] In addition, the position measurement computing device 42c calculates an index (for example, dispersion, standard deviation, or the like) that represents the degree of dispersion of data in statistics. The position measurement computing device 42c determines that the calculation accuracy of the positions of the GNSS antennas 42a, 42b is an allowable accuracy, in the case where the parameter for accuracy evaluation described above is equal to or greater than a predetermined threshold value, and the index that represents the degree of dispersion of the calculation results of the position and orientation of the rotating body 12 is less than the predetermined threshold value. On the other hand, the position measurement computing device 42c determines that the calculation accuracy of the positions of the GNSS antennas 42a, 42b is not an allowable accuracy, in the case where the parameter for accuracy evaluation described above is less than the predetermined threshold value, or in the case where the index that represents the degree of dispersion of the calculation results of the position and orientation of the rotating body 12 is equal to or greater than the predetermined threshold value.

[0119] Further, the position measurement computing device 42c can determine whether the calculation accuracy of the positions of the GNSS antennas 42a, 42b is an allowable accuracy based on the signal strength represented by the carrier-to-noise ratio (C / No).

[0120] When the communication status determination unit 43 determines that the communication status of the GNSS antennas 42a and 42b is not good, the rotation angle memory unit 44 stores the current rotation angle θ as the reference rotation angle θ0 in the ROM 20b. In other words, when the rotation angle memory unit 44 changes from a state where information related to the position and orientation of the rotating body 12 can be obtained to a state where it cannot be obtained, the rotation angle θ at this time stores the current rotation angle θ as the reference rotation angle θ0 in the ROM 20b.

[0121] The rotation posture determination unit 45 determines whether the rotating body 12 is outside the rotation range Sr determined based on the reference rotation angle θ0 or inside the rotation range Sr. Figure 9 This diagram illustrates the rotational posture determination process performed by the rotational posture determination unit 45, and is a view of the rotating body 12 from above.

[0122] like Figure 9 As shown, the rotation posture determination unit 45 calculates the difference Δθ between the rotation angle θ detected by the posture detection device 35 and the reference rotation angle θ0 stored in the ROM 20b. The difference Δθ is represented by the absolute value of the value obtained by subtracting the reference rotation angle θ0 from the rotation angle θ (Δθ=|θ-θ0|). The rotation posture determination unit 45 determines whether the rotating body 12 is located outside or inside the rotation range Sr based on the relationship between the difference Δθ and the predetermined value Δθ0.

[0123] The specified value Δθ0 is a threshold value used to define the rotation range Sr, and is pre-memorized in ROM20b. Rotating the specified value Δθ0 clockwise from the reference rotation angle θ0 to the position shown in the diagram constitutes the right end θR of the rotation range Sr, and rotating the specified value Δθ0 counterclockwise from the reference rotation angle θ0 to the position shown in the diagram constitutes the left end θL of the rotation range Sr. The specified value Δθ0 is preferably set to a value that, when the working device 1B is extended forward to its maximum extent, causes the rotation range Sr to converge to the inner side of the range connecting the left and right ends of the bucket 10 to the rotation center axis Os. The specified value Δθ0 is, for example, set to a value of 0.5 degrees to 1 degree.

[0124] If the difference Δθ is greater than the predetermined value Δθ0, the rotation posture determination unit 45 determines that the rotating body 12 is located outside the rotation range Sr. If the difference Δθ is less than or equal to the predetermined value Δθ0, the rotation posture determination unit 45 determines that the rotating body 12 is located inside the rotation range Sr.

[0125] Figure 8The target surface generating section 46 shown generates the normal target surface Sta and stores it in the ROM 20b when the communication condition of the GNSS antennas 42a, 42b is good as judged by the communication condition judging section 43. The target surface generating section 46 generates the temporary target surface Stb as a new target surface based on the normal target surface Sta generated when the communication condition is good and stores it in the ROM 20b when the communication condition of the GNSS antennas 42a, 42b is not good as judged by the communication condition judging section 43.

[0126] The target surface generating section 46 generates, as the normal target surface Sta (a two-dimensional target surface), a cross-sectional shape obtained by cutting a plane (an action plane (X-Y plane) of the work implement 1B) on which the three-dimensional target shape data acquired from the target surface setting device 36 is moved by the work implement 1B, based on the posture information (information about the posture of the work implement 1B in the earth coordinate system) from the posture calculating section 30. Further, the action plane of the work implement 1B can be calculated based on the positions of the boom pin 91, the arm pin 92, and the bucket pin 93, for example. The target surface generating section 46 sets the generated normal target surface Sta as the target surface St used in the machine control.

[0127] Figure 10A 、 Figure 10B is a view that explains the content of the generation processing of the temporary target surface Stb performed by the target surface generating section 46. Figure 10A indicates the slope αs of the target surface, Figure 10B indicates the temporary target surface. As Figure 10A shown, in the present embodiment, the normal target surface Sta is set in which a plurality of target surface elements Sta0, Sta1, Sta2 are connected.

[0128] As Figure 10A shown, the target surface generating section 46 sets, as the control position Pt, an intersection between a straight line that drops from the top end position Pb of the bucket 10 in the vertical direction (the direction of gravity) and the normal target surface Sta. Figure 10A In the example shown, the control position Pt is set on the target surface element Sta1 among the plurality of target surface elements Sta0, Sta1, Sta2. The target surface generating section 46 sets, as the slope αs of the normal target surface Sta, an angle that the target surface element Sta1 including the control position Pt makes with a horizontal plane (a reference surface) indicated by a double-dot chain line. As Figure 10B shown, the target surface generating section 46 generates the temporary target surface Stb having the same slope αs as the target surface element Sta1. The temporary target surface Stb is generated at a position that deviates by a prescribed deviation amount Hos in the vertical direction upward from the target surface element Sta1.

[0129] As Figure 10AAs shown, the target surface generating section 46 calculates a distance in the vertical direction (hereinafter referred to as a vertical distance) H between the top end position Pb of the bucket 10 and the control position Pt, and based on the vertical distance H, calculates a deviation amount Hos in the vertical direction. Figure 11 is a graph showing the relationship between the vertical distance H and the deviation amount Hos. The ROM 20b stores therein Figure 11 The vertical distance H and the deviation amount Hos shown in the table Th establish a correspondence relationship. The table Th has a characteristic that when the vertical distance H is 0 (zero), the deviation amount Hos is a minimum deviation amount Homin, and if the vertical distance H becomes larger, the deviation amount Hos becomes larger, and when the vertical distance H is a prescribed value Ha or more, the deviation amount Hos becomes a maximum deviation amount Homax. For example, the minimum deviation amount Homin is a value larger than 0 (zero), and the maximum deviation amount Homax is a value smaller than (Ya1) / (cos(aS)).

[0130] The target surface generating section 46 refers to the table Th to calculate the deviation amount Hos based on the vertical distance H. The target surface generating section 46 stores the temporary target surface Stb deviated by the deviation amount Hos in the ROM 20b. After the temporary target surface Stb is stored in the ROM 20b, if it is determined by the communication condition judging section 43 that the communication condition of the GNSS antennas 42a, 42b is good, the target surface generating section 46 eliminates the data of the temporary target surface Stb from the ROM 20b.

[0131] Figure 8 The target surface generating section 46 shown in the figure sets the temporary target surface Stb as valid in a case where it is determined by the rotation posture judging section 45 that the rotating body 12 is located inside the rotation range Sr. That is, the target surface generating section 46 sets the temporary target surface Stb as the target surface St used in the mechanical control in a case where the rotating body 12 is located inside the rotation range Sr. By setting the temporary target surface Stb as the target surface St, the distance (target surface distance) between the target surface St and the top end position Pb of the bucket 10 is made to be a prescribed distance Ya1 or less, and the mechanical control based on the target surface St (temporary target surface Stb) is executed. In this way, the controller 20 allows the execution of the mechanical control based on the target surface St when the rotating body 12 is located inside the rotation range Sr.

[0132] The target surface generating section 46 sets the temporary target surface Stb to be invalid in a case where it is judged by the rotation attitude judging section 45 that the rotating body 12 is located outside the rotation range Sr. In the present embodiment, the target surface generating section 46 sets an invalid value memorized in advance in the ROM 20b to be the target surface distance in a case where the rotating body 12 is located outside the rotation range Sr, assuming a state where the target surface St used in the mechanical control is not present. The invalid value is set to be a value at least greater than the prescribed distance Ya1. Thus, even in a case where the distance (target surface distance) between the target surface St and the top end position Pb of the bucket 10 becomes equal to or less than the prescribed distance Ya1, the mechanical control is not executed. In this way, the controller 20 prohibits execution of the mechanical control based on the target surface St when the rotating body 12 is located outside the rotation range Sr.

[0133] The notification control section 47 notifies the notification device 39 of whether the rotating body 12 is located outside or inside the rotation range Sr in a case where the execution of the mechanical control becomes impossible to acquire the position information of the rotating body 12 by the position detecting device 42. The notification control section 47 monitors whether the temporary target surface Stb is set to be valid or invalid by the target surface generating section 46. As described above, in a case where it becomes impossible to acquire the position information of the rotating body 12 by the position detecting device 42, the temporary target surface Stb is set to be valid when the rotating body 12 is located inside the rotation range Sr. In addition, in a case where it becomes impossible to acquire the position information of the rotating body 12 by the position detecting device 42, the temporary target surface Stb is set to be invalid when the rotating body 12 is located outside the rotation range Sr.

[0134] The notification control section 47 outputs a control signal (notification command) to the notification device 39 to display a message such as "The communication level is being lowered. Execution of the mechanical control based on the temporary target surface is possible." in the display screen of the notification device (display device) 39 if the temporary target surface Stb is set to be valid in the execution of the mechanical control. In addition, the notification control section 47 outputs a control signal (notification command) to the notification device 39 to display a message such as "The communication level is being lowered. Execution of the mechanical control based on the temporary target surface is impossible. Please rotate the rotating body to the original position." in the display screen of the notification device (display device) 39 if the temporary target surface Stb is set to be invalid in the execution of the mechanical control. Furthermore, the notification control section 47 can cause a display image indicating the present position of the rotating body 12 and the rotation range Sr to be displayed in the display screen of the notification device (display device) 39 together with the above messages.

[0135] The contents of the target surface setting processing performed by the controller 20 functioning as the target surface setting section 37 will be described with reference to Figure 12 and Figure 13 Figure 12 ​is a flowchart showing the contents of the target surface setting processing performed by the controller 20, Figure 13 is a flowchart showing the contents of the temporary target surface generation processing (step S120) of Figure 12 . Figure 12 The processing of the flowchart shown in FIG. 10 is started by the mechanical control being set to active by the MC switch 26, and is repeatedly performed at a prescribed control cycle after initial setting execution that is not shown.

[0136] As shown in FIG. 11, in step S101, the target surface setting section 37 acquires the position information from the position detection device 42 and the attitude information calculated by the attitude calculation section 30, and advances to step S104. Figure 12 In step S104, the target surface setting section 37 determines whether the communication condition of the GNSS antennas 42a, 42b is good based on the position information from the position detection device 42. The target surface setting section 37 determines that the communication condition of the GNSS antennas 42a, 42b is good and advances to step S157 in the case where the position information from the position detection device 42 acquired in step S101 is not a position detection error signal. The target surface setting section 37 determines that the communication condition of the GNSS antennas 42a, 42b is not good and advances to step S107 in the case where the position information from the position detection device 42 acquired in step S101 is a position detection error signal.

[0137] In step S107, the target surface setting section 37 refers to the memory device, and determines whether the temporary target surface Stb is memorized in the prescribed memory area. In step S107, if it is determined that the temporary target surface Stb is not memorized in the prescribed memory area of the memory device, the processing advances to step S110. In step S107, if it is determined that the temporary target surface Stb is memorized in the prescribed memory area of the memory device, the processing advances to step S150.

[0138] In step S110, the target surface setting section 37 memorizes the rotation angle θ of the rotating body 12 included in the attitude information acquired in step S101 as the reference rotation angle θ0 in the memory device, and advances to step S120.

[0139] In step S120, the target surface setting section 37 performs the temporary target surface generation processing. In the temporary target surface generation processing (step S120), the processing of steps S129 to S138 shown in FIG. 12 is performed.

[0140] Figure 13

[0141] As shown in FIG. 13, in step S129, the target surface setting section 37 acquires the position information from the position detection device 42 and the attitude information calculated by the attitude calculation section 30, and advances to step S130. Figure 13 ​​As shown, in step S129, the target surface setting unit 37 sets the control position Pt based on the normal target surface Sta calculated by step S163 and stored in the memory device, and the top position Pb of the bucket 10 included in the posture information obtained by step S101, and proceeds to step S132.

[0142] In step S132, the target surface setting unit 37 calculates the distance H in the vertical direction from the top position Pb of the bucket 10 to the control position Pt based on the control position Pt set in step S129 and the top position Pb of the bucket 10 included in the posture information obtained in step S101, and proceeds to step S135.

[0143] In step S135, the target surface setting unit 37 sets the slope αs of the target surface based on the normal target surface Sta calculated in step S163 and stored in the memory device, and the control position Pt set in step S120, and proceeds to step S138. In step S138, the target surface setting unit 37 calculates the deviation amount Hos based on the vertical distance H. Furthermore, the target surface setting unit 37 generates a temporary target surface Stb that deviates the surface with slope αs from the normal target surface Sta by the deviation amount Hos in the vertical direction. The target surface setting unit 37 then stores the generated temporary target surface Stb in a predetermined memory area of ​​the memory device and ends the process. Figure 13 The process is shown in the flowchart.

[0144] like Figure 12 As shown, if the temporary target surface generation process (step S120) is completed, the process proceeds to step S150. In step S150, the target surface setting unit 37 determines whether the rotating body 12 is located outside the rotation range Sr based on the rotation angle θ of the rotating body 12 included in the posture information obtained in step S101 and the reference rotation angle θ0 memorized in step S110.

[0145] In step S150, the target surface setting unit 37 calculates the difference Δθ between the rotation angle θ of the rotating body 12 and the reference rotation angle θ0. In step S150, if the difference Δθ is less than or equal to a predetermined value Δθ0, the target surface setting unit 37 determines that the rotating body 12 is located inside the rotation range Sr and proceeds to step S155. In step S150, if the difference Δθ is greater than the predetermined value Δθ0, the target surface setting unit 37 determines that the rotating body 12 is located outside the rotation range Sr and proceeds to step S153.

[0146] In step S155, the target surface setting unit 37 sets the temporary target surface Stb as the target surface St used in mechanical control in order to enable the temporary target surface Stb, and then ends the process. Figure 12the process shown in the flowchart. By setting the temporary target surface Stb as the target surface St, the state is made in which execution of the machine control based on the temporary target surface Stb is permitted. Therefore, by the controller 20, the distance between the target surface St (temporary target surface Stb) and the top end position Pb of the bucket 10 (target surface distance) is sequentially calculated, and in the case where the target surface distance is equal to or less than the prescribed distance Ya1, the machine control is executed.

[0147] In step S153, the target surface setting portion 37 sets an invalid value to the target surface distance in order to invalidate the temporary target surface Stb, and ends the process. Figure 12 the process shown in the flowchart. By setting the invalid value to the target surface distance, the state is made in which execution of the machine control based on the temporary target surface Stb is prohibited. Therefore, even in the case where the distance between the top end position Pb of the bucket 10 and the temporary target surface Stb is equal to or less than the prescribed distance Ya1, the machine control is not executed.

[0148] In step S157, the target surface setting portion 37 refers to the memory device, and determines whether or not the temporary target surface Stb is memorized in the prescribed memory area. In step S157, if it is determined that the temporary target surface Stb is not memorized in the prescribed memory area of the memory device, the process proceeds to step S163. In step S157, if it is determined that the temporary target surface Stb is memorized in the prescribed memory area of the memory device, the process proceeds to step S160.

[0149] In step S160, the target surface setting portion 37 eliminates the temporary target surface Stb memorized in the prescribed memory area of the memory device, and the process proceeds to step S163. In step S163, the target surface setting portion 37 acquires the three-dimensional target shape data from the target surface setting device 36, and generates the normal-time target surface Sta based on the acquired target shape data and the posture information (information on the posture of the working device IB with respect to the earth coordinate system) acquired in step S101, and memorizes it in the memory device. In step S160, the target surface setting portion 37 sets the generated normal-time target surface Sta as the target surface St used in the machine control, and ends the process. Figure 12 the process shown in the flowchart. By setting the normal-time target surface Sta as the target surface St, the distance between the target surface St (normal-time target surface Sta) and the top end position Pb of the bucket 10 (target surface distance) is sequentially calculated by the controller 20.

[0150] An example of the operation of the present embodiment will be described. If the operator operates the MC switch 26 to make the machine control valid, the normal-time target surface Sta is generated based on the position and orientation of the rotary body 12 calculated from the satellite signals received by the GNSS antennas 42a, 42b and the posture information detected by the posture detection device 35, and the temporary target surface Stb is generated based on the position and orientation of the rotary body 12 calculated from the satellite signals received by the GNSS antennas 42a, 42b and the posture information detected by the posture detection device 35. Figure 12S101→S104 is Y→S157 is N→S163). Therefore, the target surface St is normally set as the target surface St used in the machine control.

[0151] Therefore, for example, as shown in Figure 7 Fig. 9, if the operator performs the bucket pull-in operation to retract the boom 9, the boom raising operation is performed in such a manner that the velocity vector of the top end portion of the bucket 10 in the direction perpendicular to the target surface St becomes zero. As a result, the top end portion of the bucket 10 moves along the target surface St.

[0152] In this case, in the execution of the machine control, in the case where the communication condition of the GNSS antennas 42a, 42b deteriorates and it becomes impossible to detect the position information of the rotating body 12, the controller 20 memorizes the rotation angle Θ of the rotating body 12 at this time as the reference rotation angle Θ0, generates the temporary target surface Stb on the basis of the normal target surface Sta, and memorizes it in a prescribed memory area of the memory device Figure 12 S101→S104 is N→S107 is N→S110→S120).

[0153] In the case where the operator does not rotate the rotating body 12 and continues the bucket pull-in operation, the controller 20 sets the temporary target surface Stb as the target surface St used in the machine control Figure 12 S150 is N→S155). Therefore, the operator can continue the work based on the machine control.

[0154] The operator, after the excavated material such as earth and sand is loaded in the bucket 10, rotates the rotating body 12 to load the excavated material in the bucket 10 into a haul truck or the like. Then, in order to return the rotating body 12 to the original position, the rotating body 12 is rotated. In this case, in the case where the rotating body 12 is located inside the rotation range Sr set on the basis of the original position, the temporary target surface Stb is set as the target surface St used in the machine control Figure 12 S101→S104 is N→S107 is Y→S150 is N→S155). Therefore, the operator, after the loading work is performed, rotates the rotating body 12 to the original position, whereby the bucket 10 can be moved along the target surface St again by the machine control, and the work of land grading, excavation, or the like can be performed.

[0155] Further, in the case where the rotating body 12 is rotated in order to return the rotating body 12 to the original position after the loading work is performed, when the rotating body 12 is located outside the rotation range Sr, the temporary target surface Stb is set as invalid Figure 12in S150 is Y→S153). In addition, the operator is notified by the notification device 39 of the content of being in a state in which the temporary target surface Stb is set to be invalid. Therefore, the operator can understand that the current state is a state in which the communication condition is not good and the rotating body 12 is located outside the rotation range Sr.

[0156] If the operator makes the rotating body 12 enter inside the rotation range Sr by rotating the rotating body 12, the operator is notified by the notification device 39 of the content of being in a state in which the temporary target surface Stb is set to be valid. Therefore, the operator easily rotates the rotating body 12 to the original position and can perform the mechanical control-based work.

[0157] According to the above-described embodiment, the following operational effects are exerted.

[0158] (1) The hydraulic excavator (work machine) 1 has: a traveling body 11; a rotating body 12 rotatably mounted on the traveling body 11; a multi-joint type work device 1B mounted on the rotating body 12 and having a boom 8, a stick 9, and a bucket (work tool) 10; a position detection device 42 that detects position information of the rotating body 12; a posture detection device 35 that detects information related to a posture of the hydraulic excavator 1 including a rotation angle θ of the rotating body 12; and a controller (control device) 20 that acquires target shape data, sets a target surface St based on the acquired target shape data, the position information of the rotating body 12, and the information related to the posture of the hydraulic excavator 1, and executes mechanical control of the work device 1B based on the target surface St. The controller 20, in the execution of the mechanical control, memorizes, in a case where the position information of the rotating body 12 becomes unacquirable by the position detection device 42, rotation angle information (rotation angle θ) of the rotating body 12 detected by the posture detection device 35 at the time when the position information of the rotating body 12 becomes unacquirable by the position detection device 42 as reference rotation angle information (reference rotation angle θ0). The controller 20 prohibits execution of the mechanical control based on the target surface St when the rotating body 12 is located outside a rotation range Sr determined based on the reference rotation angle information (reference rotation angle θ0). The controller 20 permits execution of the mechanical control based on the target surface St at a time after the rotating body 12 is located inside the rotation range Sr. That is, the controller 20 prohibits execution of the mechanical control based on the target surface St when the rotating body 12 is located outside the rotation range Sr in a case where the position information of the rotating body 12 becomes unacquirable by the position detection device 42, and permits execution of the mechanical control based on the target surface St when the rotating body 12 is located inside the rotation range Sr again after being located outside the rotation range Sr.

[0159] According to this configuration, in the execution of the mechanical control, in a case where the position information of the rotating body 12 becomes unable to be acquired by the position detection device 42 due to deterioration of the communication state or the like, even if the work of loading the excavated object to the carrying vehicle by rotating the rotating body 12 is performed, it is possible to perform again the work according to the mechanical control based on the target surface St by rotating the rotating body 12 to the inside of the rotation range Sr. Therefore, according to the present embodiment, it is possible to provide the hydraulic excavator 1 capable of suppressing reduction of work efficiency.

[0160] (2) The controller 20 generates, as a new target surface, a temporary target surface Stb obtained by the gradient as of the target surface St (the target surface Sta at normal times) in a case where the position information of the rotating body 12 becomes unable to be acquired by the position detection device 42 in the execution of the mechanical control. The controller 20 permits execution of the mechanical control based on the temporary target surface Stb when the rotating body 12 is located inside the rotation range Sr.

[0161] According to this configuration, since the temporary target surface Stb is newly generated differently from the target surface (the target surface Sta at normal times) set before the position information of the rotating body 12 becomes unable to be acquired by the position detection device 42, it is possible to perform adjustment of the target surface St such as setting the temporary target surface Stb at a position different from the target surface Sta at normal times (for example, a position after deviation) or changing the gradient of the temporary target surface Stb.

[0162] (3) The controller 20 generates the temporary target surface Stb by deviating from the target surface St (the target surface Sta at normal times) by a prescribed distance (deviation amount Hos) based on the gradient as of the target surface St (the target surface Sta at normal times).

[0163] According to this configuration, in the execution of the mechanical control based on the temporary target surface Stb, in a case where the rotating body 12 is located inside the rotation range Sr, and the rotating body 12 is located at a position deviated from the reference rotation angle θ0, it is possible to prevent the shovel 10 from intruding into the lower side compared to the target surface St, and excessively excavating the target object. In a case where the temporary target surface Stb is deviated from the target surface Sta at normal times, it is possible to expand the rotation range Sr compared to a case where the temporary target surface Stb is not deviated from the target surface Sta at normal times.

[0164] (4) The controller 20 eliminates the temporary target surface Stb in a case where the position information of the rotating body 12 becomes unable to be acquired by the position detection device 42, and generates the target surface St (the target surface Sta at normal times) based on the target shape data, the position information of the rotating body 12, and the information related to the posture of the hydraulic excavator 1.

[0165] According to this configuration, in the case where the communication state is recovered, the normal target surface St (normal-time target surface Sta) is generated. Therefore, for example, in the case where the rotating body 12 is rotated to the outside of the rotation range Sr, the normal target surface St (normal-time target surface Sta) is newly generated on the basis of the posture of the hydraulic excavator 1 at that time. Therefore, it is possible to shift to other site for excavation, land grading, or the like.

[0166] (5) The hydraulic excavator 1 further has a notification device 39 that notifies the operator. The controller 20, in the execution of the machine control, in the case where the position information of the rotating body 12 cannot be acquired by the position detection device 42, notifies the notification device 39 of whether the rotating body 12 is located on the outside or on the inside of the rotation range Sr. The notification device 39 notifies the operator on the basis of the notification instruction from the controller 20.

[0167] According to this configuration, the operator can easily confirm whether or not the state where the operation based on the machine control is executable in the state where the communication state is not good. Therefore, after the rotating body 12 is rotated and the loading operation is performed, it is possible to easily and quickly rotate the rotating body 12 to the position (original position) where the operation based on the machine control is executable. As a result, it is possible to seek improvement of the work efficiency. In addition, in the state where the communication state is not good and the rotating body 12 is located on the outside of the rotation range Sr, it is possible to perform attention arousal so that the operation based on the operator is not performed.

[0168] The following modified examples also belong to the scope of the present application, and it is also possible to combine the configuration shown in the modified examples with the configuration described in the above-described embodiments, or to combine the configurations described in the following different modified examples with each other.

[0169] <Modified Example 1>

[0170] In the above-described embodiments, the following example is described: when the state where the communication state is good changes to the state where the communication state is not good, the temporary target surface Stb is newly generated as the target surface different from the normal-time target surface Sta, and the temporary target surface Stb is set as the target surface St used in the machine control, but the present application is not limited to this. It is also possible that, in the case where the state where the communication state is good changes to the state where the communication state is not good, the controller 20 maintains the target surface St (normal-time target surface Sta) set now, and the machine control is executed on the basis of this target surface St (normal-time target surface Sta) when the rotating body 12 is located on the inside of the rotation range Sr.

[0171] That is, the controller 20 prohibits execution of the mechanical control based on the held normal-time target surface Sta when the position information of the rotating body 12 becomes unable to be acquired by the position detection device 42 and the rotating body 12 is located outside the rotation range Sr, and permits execution of the mechanical control based on the held normal-time target surface Sta when the rotating body 12 is located inside the rotation range Sr.

[0172] <Modification example 2>

[0173] In the above-described embodiment, an example is described in which the intersection between the straight line that drops vertically from the top end position Pb of the shovel 10 and the normal-time target surface Sta is set as the control position Pt, and the temporary target surface Stb is generated based on the target surface element Stal including the control position Pt, but the present application is not limited thereto. As shown in FIG. 12, the temporary target surface Stb can also be generated by causing the plurality of target surface elements StaO, Stal, and Sta2 to each deviate, connecting each of the intersections of the plurality of surfaces (lines) after the deviation to each other, and thereby generating the temporary target surface Stb. Figure 14

[0174] <Modification example 3>

[0175] In the above-described embodiment, an example is described in which the controller 20 sets the deviation amount Hos based on the vertical distance H, but the present application is not limited thereto. The controller 20 can also generate the temporary target surface Stb using a deviation amount (constant) memorized in advance in the ROM 20b.

[0176] <Modification example 4>

[0177] In the above-described embodiment, an example is described in which the notification device 39 is a display device, but the present application is not limited thereto. As the notification device 39, an audio output device, a light emitting device, a vibration device, or the like that notifies the operator of whether the rotating body 12 is located outside or inside the rotation range Sr by sound, light, or vibration can also be employed.

[0178] <Modification example 5>

[0179] The function of the position detection operation device 42c of the position detection device 42 can also be possessed by the controller (control device) 20.

[0180] <Modification example 6>

[0181] In the above-described embodiment, an example is described in which the work machine is the crawler hydraulic excavator 1, but the present application is not limited thereto. The present application can also be applied to various work machines such as a wheel hydraulic excavator, a rotating body rotatably mounted on a traveling body, and a work device mounted on the rotating body.

[0182] <Modification example 7>​

[0183] In the above-described embodiments, an example in which the operation devices 15A to 15D are hydraulic pilot type operation devices has been described, but the present application is not limited to this. It can also be an example in which an electric type operation device is provided, and the controller controls an electromagnetic proportional valve based on an electric signal from the operation device, thereby driving the flow control valves 16a to 16d.

[0184] <Modification example 8>

[0185] In the above-described embodiments, an example in which the actuation mechanisms that drive the boom 8, the arm 9, and the bucket 10 are hydraulic cylinders has been described, but the present application is not limited to this. The actuation mechanisms that drive the boom 8, the arm 9, and the bucket 10 can also be electric cylinders.

[0186] <Modification example 9>

[0187] The functions of the control device (controller 20) described in the above-described embodiments can also be implemented in part or in whole by hardware (for example, logic that performs each function by integrated circuit design, and the like).

[0188] The above-described embodiments have been described, but the above-described embodiments only represent a part of examples of applications of the present application, and are not intended to limit the technical scope of the present application to the specific configurations of the above-described embodiments.

[0189] Explanation of reference numerals

[0190] 1 … hydraulic shovel (work machine), 1B … work device, 8 … boom, 9 … arm, 10 … bucket (work tool), 11 … traveling body, 12 … rotating body, 20 … controller (control device), 21 to 24 … angle sensor (attitude sensor), 35 … attitude detection device, 36 … target surface setting device, 39 … notification device, 42 … position detection device, 42a, 42b … GNSS antenna, 42c … position measurement calculation device, 60 … hydraulic control unit, 100 … hydraulic drive device, H … vertical distance, Hos … offset amount, Pb … top end position, Pt … control position, Sr … rotation range, St … target surface, Sta … normal target surface, Stb … temporary target surface, Ya1 … distance, a … boom angle, as … slope, b … arm angle, g … bucket angle, q … rotation angle, q0 … reference rotation angle.

Claims

1. A work machine having: a traveling body; a rotary body rotatably mounted to the traveling body; a work device mounted to the rotary body; a position detection device that detects position information of the rotating body; a posture detection device that detects information related to a posture of the work machine including a rotation angle of the rotating body; and a control device that acquires target shape data, sets a target surface based on the acquired target shape data, the position information of the rotating body, and the information related to the posture of the work machine, and executes mechanical control of the work device based on the target surface, the work machine being characterized in that the control device is configured to: in a case where the position information of the rotating body becomes unacquirable by the position detection device, memorize, as reference rotation angle information, rotation angle information detected by the posture detection device when the position information of the rotating body becomes unacquirable by the position detection device, when the rotating body is located outside a rotation range determined based on the reference rotation angle information, prohibit execution of the mechanical control based on the target surface, when the rotating body is located inside the rotation range and when the rotating body is located inside the rotation range again after being located outside the rotation range, allow execution of the mechanical control based on the target surface.

2. The work machine according to claim 1, characterized in that the control device is configured to: in a case where the position information of the rotating body becomes unacquirable by the position detection device, generate, as a new target surface, a temporary target surface based on a gradient of the target surface, when the rotating body is located inside the rotation range, allow execution of the mechanical control based on the temporary target surface.

3. The work machine according to claim 2, characterized in that the control device generates the temporary target surface based on the gradient of the target surface so that the temporary target surface deviates from the target surface by only a prescribed distance.

4. The work machine according to claim 2, characterized in that the control device, in a case where the position information of the rotating body becomes unacquirable by the position detection device, eliminates the temporary target surface and generates a target surface based on the target shape data, the position information of the rotating body, and the information related to the posture of the work machine.

5. The work machine according to claim 1, characterized in that further comprising a notification device that notifies an operator, the control device, in a case where the position information of the rotating body becomes unacquirable by the position detection device, notifies the notification device of whether the rotating body is located outside the rotation range or inside the rotation range.

6. The work machine according to claim 1, characterized in that the control device is configured to: in a case where the position information of the rotating body becomes unacquirable by the position detection device, memorize, as reference rotation angle information, rotation angle information when the position information of the rotating body becomes unacquirable by the position detection device, In a case where a difference between the rotation angle detected by the posture detection device and the reference rotation angle is greater than a prescribed value, execution of the mechanical control based on the target surface is prohibited, and in a case where the difference between the rotation angle detected by the posture detection device and the reference rotation angle is equal to or less than the prescribed value, execution of the mechanical control based on the target surface is permitted.

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