Construction machine control device for construction machine and construction machine

Abstract

A construction machine control device according to the present invention comprises a controller (70) that performs automatic control of a work device (4) of a construction machine (1) to move a tip attachment (8) of the work device (4) toward a preset target construction surface. The controller (70) continues the automatic control until the speed of a specific portion of the work device (4) or a specific value that is correlated with the speed is at or below a specific threshold value for determining suspension of the operation of the work device (4).

Description

CONSTRUCTION MACHINE CONTROL DEVICE FOR CONSTRUCTION MACHINE AND CONSTRUCTION MACHINE

[0001] The present invention relates to a control device for a construction machine having an automatic control function.

[0002] The work machine disclosed in Patent Document 1 includes a work implement having a bucket, a first hydraulic actuator that drives the work implement, an operating device that outputs a first control signal for the first hydraulic actuator in response to operation by an operator, a control device that stores information about a target construction surface that is a target shape of a work target of the work implement and calculates a second control signal that operates the first hydraulic actuator so that the work implement is positioned above the target construction surface, and a switching device that can select either an ON position or an OFF position. When the switching device is switched to the ON position, the control device outputs either the first control signal or the second control signal to control the operation of the first hydraulic actuator, and when the switching device is switched to the OFF position, the control device outputs the first control signal to control the operation of the first hydraulic actuator. The control device stores a table that defines the relationship between a target construction surface distance, which is the distance between the bucket and the target construction surface, and a limit value for the time rate of change of the switching of the control signal for operating the first hydraulic actuator when the switching device switches from the OFF position to the ON position or from the ON position to the OFF position, and the control device limits the time rate of change of the switching of the control signal for the first hydraulic actuator when the switching device switches from the OFF position to the ON position or from the ON position to the OFF position to a predetermined time rate limit value determined from the target construction surface distance and the table. Patent Document 1 describes that because the time rate of change of the switching of the control signal for the first hydraulic actuator when the switching device switches from the ON position to the OFF position is limited to the predetermined time rate limit value, a sudden change in actuator speed is suppressed.

[0003] Patent No. 6966312

[0004] However, in the technology described in Patent Document 1, when the switching device is switched from the ON position to the OFF position, the first control signal, which is the pilot pressure generated by the operating lever, is issued, rather than the second control signal that operates the first hydraulic actuator so that the working device is positioned above the target construction surface. In other words, when the switching device is switched from the ON position to the OFF position, automatic control that operates the first hydraulic actuator so that the working device is positioned above the target construction surface is not performed, but control is performed based on the first control signal in response to operation of the operating lever by the operator. Therefore, it may be impossible to accurately move a tip attachment such as a bucket close to the target construction surface. In this case, construction accuracy cannot be maintained.

[0005] An object of the present invention is to provide a control device for a construction machine that can accurately move a tip attachment close to a target construction surface under automatic control.

[0006] A construction machine control device according to one aspect of the present invention is a control device for a construction machine equipped with a work device including a boom, an arm rotatably connected to the tip of the boom, and a tip attachment rotatably connected to the tip of the arm, and the construction machine control device comprises a controller that performs automatic control of the work device to move the tip attachment toward a predetermined target construction surface, and the controller continues the automatic control until the speed of a specific part of the work device or a specific value that is a value correlated to this speed becomes equal to or less than a specific threshold that is a threshold for determining whether to stop the operation of the work device.

[0007] A construction machine according to another aspect of the present invention includes the work implement and the construction machine control device.

[0008] Fig. 1 is a side view showing an example of a construction machine according to an embodiment of the present disclosure. Fig. 2 is a diagram illustrating a system structure of the construction machine of Fig. 1. Fig. 3 is a flowchart illustrating a first control example for moving a bucket toward a target construction surface. Fig. 4 is a flowchart illustrating a second control example for moving a bucket toward a target construction surface.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following embodiment is an example of a specific embodiment of the present invention and is not intended to limit the technical scope of the present invention.

[0010] Fig. 1 is a side view showing an example of a construction machine 1 according to an embodiment of the present disclosure. The construction machine 1 shown in Fig. 1 is a hydraulic excavator.

[0011] The construction machine 1 includes a lower traveling structure 2, an upper rotating structure 3 rotatably supported on the lower traveling structure 2, and a working implement 4 mounted on the upper rotating structure 3 so as to be able to rise and fall. The lower traveling structure 2 has crawlers 2a, but may also have tires (not shown). The upper rotating structure 3 has a rotating frame 3a supported on the lower traveling structure 2, a cab disposed on the rotating frame 3a, and a counterweight. The working implement 4 includes a boom 6, an arm 7 rotatably connected to the tip of the boom 6, and a bucket 8 rotatably connected to the tip of the arm 7. The bucket 8 is an example of a tip attachment.

[0012] 2 is a diagram illustrating the system structure of the construction machine 1. The construction machine 1 includes a plurality of hydraulic actuators that operate the work implement 4 and the upper rotating body 3, a plurality of operating members 19 that are operated to operate the work implement 4 and the upper rotating body 3, a hydraulic pump 15 that supplies hydraulic oil to the plurality of hydraulic actuators, a pilot pump 16, a control valve 23 that switches the supply path of hydraulic oil supplied to each of the plurality of hydraulic actuators, and a construction machine control device. The construction machine control device includes a controller 70. The control valve 23 includes a plurality of proportional valves 20 and a plurality of directional control valves 22.

[0013] In this embodiment, the multiple hydraulic actuators include a boom cylinder 9 for rotating the boom 6, an arm cylinder 10 for rotating the arm 7, a bucket cylinder 11 for rotating the bucket 8, a swing motor 12 for rotating the upper swing body 3, and a travel motor (not shown). The multiple actuators are operated by the supply of hydraulic oil discharged from a hydraulic pump 15.

[0014] The boom 6 is rotatably attached to the upper rotating body 3, and performs a raising and lowering operation relative to the upper rotating body 3 in accordance with the extension and contraction operation of the boom cylinder 9. Specifically, when the boom cylinder 9 contracts, the boom 6 performs a boom-lowering operation in which the tip of the boom 6 approaches the ground G. When the boom cylinder 9 extends, the boom 6 performs a boom-raising operation in which the tip of the boom 6 moves away from the ground G.

[0015] The arm 7 is rotatably attached to the tip of the boom 6, and performs a rotational movement in which it rotates relative to the boom 6 as the arm cylinder 10 extends and retracts. Specifically, when the arm cylinder 10 retracts, the arm 7 performs an arm-pushing movement in which the tip of the arm 7 moves away from the boom 6. When the arm cylinder 10 extends, the arm 7 performs an arm-pulling movement in which the tip of the arm 7 moves toward the boom 6.

[0016] The bucket 8 is rotatably attached to the tip of the arm 7, and performs a rotational movement in which it rotates relative to the arm 7 as the bucket cylinder 11 extends and retracts. Specifically, when the bucket cylinder 11 retracts, the bucket 8 performs a bucket earth-discharging movement (bucket pushing movement). The bucket earth-discharging movement is, for example, an operation performed when material such as soil and sand held in the bucket 8 is discharged to a discharge destination such as the bed of a truck. When the bucket cylinder 11 extends, the bucket 8 performs a bucket excavating movement (bucket pulling movement). The bucket excavating movement is, for example, an operation performed when the bucket 8 is used to excavate an excavation target such as the ground.

[0017] The upper rotating body 3 performs a rotation operation (right rotation operation or left rotation operation) to rotate about a vertical axis relative to the lower traveling body 2 in accordance with the operation of the rotation motor 12. The lower traveling body 2 performs a traveling operation to travel on the ground in accordance with the operation of the traveling motor.

[0018] The multiple operating members 19 include multiple members that are subjected to various operations by the operator. Specifically, for example, the multiple operating members 19 may include a boom operating member 19a for operating the boom 6, an arm operating member 19b for operating the arm 7, a bucket operating member 19c for operating the bucket 8, a swing operating member 19d for operating the swing of the upper swing structure 3, and a travel operating member 19e for operating the travel of the lower traveling structure 2. Each of the multiple operating members 19 may be an operating lever or an operating pedal.

[0019] The boom operation member 19a receives boom operation by the operator. The boom operation is a boom lowering operation or a boom raising operation. The boom lowering operation is an operation for causing the boom 6 to perform a boom lowering operation, and the boom raising operation is an operation for causing the boom 6 to perform a boom raising operation. The arm operation member 19b receives arm operation by the operator. The arm operation is an arm pushing operation or an arm pulling operation. The arm pushing operation is an operation for causing the arm 7 to perform an arm pushing operation, and the arm pulling operation is an operation for causing the arm 7 to perform an arm pulling operation. The bucket operation member 19c receives bucket operation by the operator. The bucket operation is a bucket earth dumping operation or a bucket digging operation. The bucket earth dumping operation is an operation for causing the bucket 8 to perform a bucket earth dumping operation, and the bucket digging operation is an operation for causing the bucket 8 to perform a bucket digging operation. The swing operation member 19d receives swing operation by the operator. The swing operation is a right swing operation or a left swing operation. The right turning operation is an operation for making the upper rotating body 3 turn right, and the left turning operation is an operation for making the upper rotating body 3 turn left. The travel operating member 19e receives a travel operation by the operator for making the lower traveling body 2 travel.

[0020] The construction machine 1 is equipped with multiple operation detectors 21. The multiple operation detectors 21 include a boom operation detector 21a, an arm operation detector 21b, a bucket operation detector 21c, a swing operation detector 21d, and a travel operation detector 21e. The boom operation detector 21a detects the boom operation amount Lbm of the boom lowering operation and the boom operation amount Lbm of the boom raising operation performed by the boom operation member 19a. The arm operation detector 21b detects the arm operation amount La of the arm pushing operation and the arm operation amount La of the arm pulling operation performed by the arm operation member 19b. The bucket operation detector 21c detects the bucket operation amount Lbk of the bucket earth removal operation and the bucket operation amount Lbk of the bucket excavation operation performed by the bucket operation member 19c. The swing operation detector 21d detects the swing operation amount Lsw of the right swing operation and the swing operation amount Lsw of the left swing operation performed by the swing operation member 19d. The driving operation detector 21e detects the driving operation amount of the driving operation received by the driving operation member 19e. Each of the plurality of operation detectors 21 inputs the detection result to the controller 70.

[0021] The construction machine 1 may be provided with a remote control valve that outputs a pilot pressure (secondary pressure) corresponding to the amount of operation received by the operating member 19. In this case, each of the multiple operation detectors 21 may be a pressure sensor that detects a pilot pressure corresponding to the amount of operation.

[0022] The hydraulic pump 15 supplies hydraulic oil to at least one of the plurality of hydraulic actuators. The hydraulic pump 15 may be composed of only one hydraulic pump, or may include a plurality of hydraulic pumps (for example, two hydraulic pumps). The hydraulic pump 15 is driven by the engine 5 to discharge hydraulic oil. The pilot pump 16 is driven by the engine 5 to discharge hydraulic oil to be supplied to each of the plurality of directional control valves 22.

[0023] The plurality of proportional valves 20 may include a first boom proportional valve 20 a, a second boom proportional valve 20 b, a first arm proportional valve 20 c, a second arm proportional valve 20 d, a first bucket proportional valve 20 e, a second bucket proportional valve 20 f, a first swing proportional valve 20 g, and a second swing proportional valve 20 h. Each of the plurality of proportional valves 20 is an electromagnetic proportional valve that outputs a secondary pressure (pilot pressure) according to a command (current command value) input from controller 70.

[0024] The multiple direction switching valves 22 may include a boom direction switching valve 22a, an arm direction switching valve 22b, a bucket direction switching valve 22c, and a swing direction switching valve 22d.

[0025] The boom direction switching valve 22a switches the direction in which hydraulic oil discharged from the hydraulic pump 15 is supplied to the boom cylinder 9. The boom direction switching valve 22a has a spool that moves in response to the first pilot pressure output from the first boom proportional valve 20a and the second pilot pressure output from the second boom proportional valve 20b. The boom direction switching valve 22a has a first pilot port that receives the first pilot pressure of the first boom proportional valve 20a and a second pilot port that receives the second pilot pressure of the second boom proportional valve 20b.

[0026] For example, when the controller 70 inputs a boom-raising command (current command value) to the first boom proportional valve 20a, a first pilot pressure corresponding to the boom-raising command is supplied from the first boom proportional valve 20a to the first pilot port. At this time, the boom direction switching valve 22a opens to allow hydraulic oil to be supplied to the head side chamber of the boom cylinder 9 and hydraulic oil discharged from the rod side chamber of the boom cylinder 9 to return to the tank. As a result, the boom cylinder 9 extends at a speed corresponding to the boom-raising command, and the boom 6 performs a boom-raising operation at a speed corresponding to the boom-raising command. Furthermore, when the controller 70 inputs a boom-lowering command (current command value) to the second boom proportional valve 20b, a second pilot pressure corresponding to the boom-lowering command is supplied from the second boom proportional valve 20b to the second pilot port. At this time, the boom direction switching valve 22a opens to allow hydraulic oil to be supplied to the rod side chamber of the boom cylinder 9 and hydraulic oil discharged from the head side chamber of the boom cylinder 9 to return to the tank. As a result, the boom cylinder 9 contracts at a speed corresponding to the boom lowering command, and the boom 6 performs a boom lowering operation at a speed corresponding to the boom lowering command.

[0027] The arm direction switching valve 22b switches the direction in which hydraulic oil discharged from the hydraulic pump 15 is supplied to the arm cylinder 10. The arm direction switching valve 22b has a spool that moves in response to the first pilot pressure output from the first arm proportional valve 20c and the second pilot pressure output from the second arm proportional valve 20d. The arm direction switching valve 22b has a first pilot port that receives the first pilot pressure of the first arm proportional valve 20c and a second pilot port that receives the second pilot pressure of the second arm proportional valve 20d.

[0028] For example, when the controller 70 inputs an arm pull command (current command value) to the first arm proportional valve 20c, a first pilot pressure corresponding to the arm pull command is supplied from the first arm proportional valve 20c to a first pilot port. At this time, the arm direction switching valve 22b opens to allow hydraulic oil to be supplied to the head side chamber of the arm cylinder 10 and hydraulic oil discharged from the rod side chamber of the arm cylinder 10 to return to the tank. As a result, the arm cylinder 10 extends at a speed corresponding to the arm pull command, and the arm 7 performs an arm pull operation at a speed corresponding to the arm pull command. Also, when the controller 70 inputs an arm push command (current command value) to the second arm proportional valve 20d, a second pilot pressure corresponding to the arm push command is supplied from the second arm proportional valve 20d to a second pilot port. At this time, the arm direction switching valve 22b opens to allow hydraulic oil to be supplied to the rod side chamber of the arm cylinder 10 and hydraulic oil discharged from the head side chamber of the arm cylinder 10 to return to the tank. As a result, the arm cylinder 10 contracts at a speed according to the arm pushing command, and the arm 7 performs an arm pushing operation at a speed according to the arm pushing command.

[0029] The bucket directional control valve 22c switches the direction in which hydraulic oil discharged from the hydraulic pump 15 is supplied to the bucket cylinder 11. The bucket directional control valve 22c has a spool that moves in response to a first pilot pressure output from the first bucket proportional valve 20e and a second pilot pressure output from the second bucket proportional valve 20f. The bucket directional control valve 22c has a first pilot port that receives the first pilot pressure of the first bucket proportional valve 20e and a second pilot port that receives the second pilot pressure of the second bucket proportional valve 20f.

[0030] For example, when the controller 70 inputs a bucket pulling command (current command value) to the first bucket proportional valve 20e, a first pilot pressure corresponding to the bucket pulling command is supplied from the first bucket proportional valve 20e to a first pilot port. At this time, the bucket directional control valve 22c opens to allow hydraulic oil to be supplied to the head side chamber of the bucket cylinder 11 and hydraulic oil discharged from the rod side chamber of the bucket cylinder 11 to return to the tank. As a result, the bucket cylinder 11 extends at a speed corresponding to the bucket pulling command, and the bucket 8 performs a bucket pulling operation at a speed corresponding to the bucket pulling command. Furthermore, when the controller 70 inputs a bucket pushing command (current command value) to the second bucket proportional valve 20f, a second pilot pressure corresponding to the bucket pushing command is supplied from the second bucket proportional valve 20f to a second pilot port. At this time, the bucket directional control valve 22c opens to allow hydraulic oil to be supplied to the rod side chamber of the bucket cylinder 11 and hydraulic oil discharged from the head side chamber of the bucket cylinder 11 to return to the tank. As a result, the bucket cylinder 11 contracts at a speed according to the bucket pushing command, and the bucket 8 performs the bucket pushing operation at a speed according to the bucket pushing command.

[0031] The swing direction switching valve 22d switches the direction in which hydraulic oil discharged from the hydraulic pump 15 is supplied to the swing motor 12. The swing direction switching valve 22d has a spool that moves in response to the first pilot pressure Ppi1 output from the first swing proportional valve 20g and the second pilot pressure Ppi2 output from the second swing proportional valve 20h. The swing direction switching valve 22d has a first pilot port that receives the first pilot pressure Ppi1 of the first swing proportional valve 20g and a second pilot port that receives the second pilot pressure Ppi2 of the second swing proportional valve 20h.

[0032] For example, when the controller 70 inputs a left swing command (current command value) to the first swing proportional valve 20g, a first pilot pressure Ppi1 corresponding to the left swing command is supplied from the first swing proportional valve 20g to the first pilot port. At this time, the swing direction switching valve 22d opens so as to supply hydraulic oil to the first port of the swing motor 12 and allow hydraulic oil discharged from the second port of the swing motor 12 to return to the tank. As a result, the swing motor 12 swings left at a speed corresponding to the left swing command, and the upper swing body 3 performs a left swing operation at a speed corresponding to the left swing command. Furthermore, when the controller 70 inputs a right swing command (current command value) to the second swing proportional valve 20h, a second pilot pressure Ppi2 corresponding to the right swing command is supplied from the second swing proportional valve 20h to the second pilot port. At this time, the swing direction switching valve 22d opens so that hydraulic oil is supplied to the second port of the swing motor 12 and hydraulic oil discharged from the first port of the swing motor 12 returns to the tank. As a result, the swing motor 12 swings right at a speed according to the right swing command, and the upper swing body 3 performs a right swing operation at a speed according to the right swing command.

[0033] The controller 70 has a computer including an arithmetic processing unit and a memory. The controller 70 controls the operation of the construction machine 1 by the arithmetic processing unit executing a program stored in the memory.

[0034] The construction machine 1 is equipped with a plurality of angle sensors 24. Detection values ​​(angles) detected by the plurality of angle sensors 24 are input to the controller 70. The plurality of angle sensors 24 include a first angle sensor 24a to a fifth angle sensor 24e. The first angle sensor 24a detects a boom angle θa of the boom 6. The second angle sensor 24b detects an arm angle θb of the arm 7. The third angle sensor 24c detects a bucket angle θc of the bucket 8. The fourth angle sensor 24d detects a swing angle θd of the upper rotating body 3. The fourth angle sensor 24d may also detect a swing angle θd of the swing motor 12 that swings the upper rotating body 3. The fifth angle sensor 24e detects an inclination angle θe of the construction machine 1. The inclination angle θe may be, for example, an inclination angle of the lower traveling body 2 or the upper rotating body 3 with respect to a horizontal plane.

[0035] The construction machine 1 may also be equipped with multiple pressure sensors 25 (hydraulic sensors). In this case, detected values ​​(pressures) detected by the multiple pressure sensors 25 are input to the controller 70. The multiple pressure sensors 25 include a first pressure sensor 25a to an eighth pressure sensor 25h. The first pressure sensor 25a detects the pressure in the head side chamber of the boom cylinder 9. The second pressure sensor 25b detects the pressure in the rod side chamber of the boom cylinder 9. The third pressure sensor 25c detects the pressure in the head side chamber of the arm cylinder 10. The fourth pressure sensor 25d detects the pressure in the rod side chamber of the arm cylinder 10. The fifth pressure sensor 25e detects the pressure in the head side chamber of the bucket cylinder 11. The sixth pressure sensor 25f detects the pressure in the rod side chamber of the bucket cylinder 11. The seventh pressure sensor 25g detects the pressure of the hydraulic oil at one port of the swing motor 12. The eighth pressure sensor 25h detects the pressure of the hydraulic oil at the other port of the swing motor 12.

[0036] The construction machine 1 may also be equipped with multiple speed sensors 26. In this case, detected values ​​(speeds V) detected by the multiple speed sensors 26 are input to the controller 70. The multiple speed sensors 26 include a first speed sensor 26a to a fourth speed sensor 26d. The first speed sensor 26a detects a boom speed Vbm. The boom speed Vbm is the speed of the boom 6 or the speed of the boom cylinder 9, which is a value correlated to that speed. The second speed sensor 26b detects an arm speed Va. The arm speed Va is the speed of the arm 7 or the speed of the arm cylinder 10, which is a value correlated to that speed. The third speed sensor 26c detects a bucket speed Vbk. The bucket speed Vbk is the speed of the bucket 8 or the speed of the bucket cylinder 11, which is a value correlated to that speed. The fourth speed sensor 26d detects a swing speed Vsw. The swing speed Vsw is the swing speed of the upper swing body 3 or the speed of the swing motor 12, which is a value correlated to the swing speed. The arm speed Va is an example of a specific value in the present disclosure and an example of an arm specific value in the present disclosure.

[0037] The construction machine 1 also includes a machine control switch 28 (hereinafter referred to as the MC switch 28). An on / off switching signal output from the MC switch 28 is input to the controller 70. The MC switch 28 may be, for example, a switch displayed on a touch panel, or a mechanical switch such as a seesaw switch. The MC switch 28 is switched by the operator, and can be switched while the operating member 19 is being operated. The MC switch 28 does not necessarily have to be a switch displayed on the touch panel or a seesaw switch, but may be any switching device that can switch the automatic control described below on and off.

[0038] The MC switch 28 is a switch for switching between automatic control of the work implement 4 by the controller 70 and normal control in response to manual operation by the operator. When the MC switch 28 is switched to the ON position, the controller 70 switches the control mode of the construction machine 1 to a mode for automatic control, and when the MC switch 28 is switched to the OFF position, the controller 70 switches the control mode to a manual operation mode.

[0039] The construction machine 1 is equipped with a target construction surface setting device 30. The target construction surface setting device 30 is a device for setting a target construction surface that serves as a target when executing automatic control. The target construction surface setting device 30 may include an imaging device such as a camera that captures images of the work site, and a monitor that displays images captured by the imaging device. The monitor may be a monitor that is pre-installed in the cab. The target construction surface setting device 30 is operated by the operator before work begins.

[0040] The operator displays an image of the work site captured by the imaging device of the target construction plane setting device 30 on the monitor. Next, the operator sets a target construction plane on the monitor. For example, when the operator designates multiple points (e.g., two points) on the monitor, the target construction plane setting device 30 sets a target construction plane based on the designated multiple points. Specifically, for example, when the operator designates two points on the monitor, the target construction plane setting device 30 sets a line connecting the two designated points as the target construction plane. Alternatively, the operator may designate three points on the monitor. In this case, the target construction plane setting device 30 may set a plane including the three designated points as the target construction plane. The target construction plane setting device 30 stores the set target construction plane and inputs it to the controller 70. Note that the method of setting the target construction plane is not limited to the above. For example, when the operator operates the operating member 19 to move the tip of the bucket 8 to a position that should be included in the target construction plane, the operator performs an input operation on the target construction plane setting device 30, and the target construction plane setting device 30 stores the position (coordinates) of the tip of the bucket 8. By repeating this operation multiple times, the target construction surface setting device 30 can store multiple positions (coordinates) to be included in the target construction surface, and the target construction surface may be set based on the multiple positions (coordinates). Also, the target construction surface setting device 30 may set the target construction surface based on data read from a storage medium that stores data related to the target construction surface.

[0041] When MC switch 28 is switched from the OFF position to the ON position, controller 70 automatically controls the movement of arm 7, boom 6, and bucket 8 based on arm operation amount La, which is the amount of arm operation received by arm operating member 19b, so that bucket 8 moves to a preset target construction surface. In this embodiment, because automatic control is executed, the operator can move bucket 8 toward the target construction surface by operating only arm operating member 19b, without operating boom operating member 19a and bucket operating member 19c. This reduces the burden on the operator.

[0042] When MC switch 28 is switched to the ON position, controller 70 begins automatic control to move bucket 8 to the target construction surface based on the arm operation amount La of arm operating member 19b. For example, controller 70 calculates the position of bucket 8 (e.g., the position of the tip of bucket 8) from boom angle θa, arm angle θb, bucket angle θc, swing angle θsw, vehicle body tilt angle θe, etc. This allows controller 70 to obtain information about the relative position of bucket 8 with respect to the target construction surface. Controller 70 may specify the position of bucket 8 and the target construction surface using coordinates in a predetermined coordinate system. The predetermined coordinate system may be a coordinate system whose origin is a specific portion of construction machine 1, a coordinate system whose origin is a specific location on the work site, or a global coordinate system.

[0043] The information about the relative position may include a height deviation e, which is the deviation between the height of the target construction surface and the height of the bucket 8. For example, as shown in FIG. 1 , the height deviation e may be the distance between the height of the target construction surface set on the ground G and the height of the tip of the bucket 8 (the cutting edge of the bucket 8). The information about the relative position may also include the coordinates of the tip of the bucket 8 and information specifying the target construction surface. The information specifying the target construction surface may include an equation representing the target construction surface. If the target construction surface is a flat surface, the equation representing the target construction surface may be an equation for the plane. If the target construction surface is a horizontal surface, the information specifying the target construction surface may include information about the height of the target construction surface.

[0044] The controller 70 can identify the position (coordinates) of the bucket 8 in the predetermined coordinate system based on the detection values ​​detected by the plurality of angle sensors 24. The controller 70 can calculate the height deviation e based on the identified position of the bucket 8 and information that identifies the target construction surface.

[0045] The controller 70 may control the boom cylinder 9, the arm cylinder 10, and the bucket cylinder 11 based on the relative positions so that the bucket 8 moves toward the target construction surface.

[0046] [First Control Example: Feedforward Control and Feedback Control] The controller 70 may perform the following feedforward control and feedback control in the automatic control. For example, in the automatic control, the controller 70 may calculate an arm target value based on the arm operation amount La of the arm operating member 19b, and perform feedforward control to operate the arm cylinder 10 based on this arm target value, and may also perform feedback control to operate the boom cylinder 9 and the bucket cylinder 11 based on the height deviation e. The arm target value may be a target value for the speed of the arm 7 (arm target speed), or may be a target value for the operating speed of the arm cylinder 10 (arm target speed), which is a value correlated to this target value.

[0047] In this case, the controller 70 may store in advance a relational expression or a map such as a look-up table that expresses the relationship between the arm operation amount La and the arm target value. The controller 70 may calculate the arm target value corresponding to the arm operation amount La by applying the arm operation amount La to the map. The relational expression may be, for example, Equation (3) described later. The controller 70 inputs an arm operation command value Ia corresponding to the arm target value to the arm proportional valve (the first arm proportional valve 20c or the second arm proportional valve 20d). This causes the arm cylinder 10 to operate at a speed corresponding to the arm operation amount La. In this case, the controller 70 may store in advance a relational expression or a map such as a look-up table that expresses the relationship between the arm target value and the arm operation command value Ia. The controller 70 may calculate the arm operation command value Ia corresponding to the arm target value by applying the arm target value to the map.

[0048] Furthermore, the controller 70 calculates a boom operation command value Ibm and a bucket operation command value Ibk according to the height deviation e, inputs the boom operation command value Ibm to the boom proportional valve (first boom proportional valve 20a or second boom proportional valve 20b), and inputs the bucket operation command value Ibk to the bucket proportional valve (first bucket proportional valve 20e or second bucket proportional valve 20f). As a result, the boom cylinder 9 and the bucket cylinder 11 each operate at a speed according to the height deviation e. In this case, the controller 70 may previously store a relational expression or a map such as a look-up table that expresses the relationship between the height deviation e and the boom operation command value Ibm. The controller 70 may calculate the boom operation command value Ibm according to the height deviation e by applying the height deviation e to the map. Similarly, the controller 70 may previously store a relational expression or a map such as a look-up table that expresses the relationship between the height deviation e and the bucket operation command value Ibk. Controller 70 may calculate a bucket operation command value Ibk corresponding to height deviation e by applying height deviation e to the map. Bucket operation command value Ibk is an example of a tip attachment command value.

[0049] [Second Control Example: Feedforward Control] Furthermore, the controller 70 may perform the following feedforward control in the automatic control. For example, in the automatic control, the controller 70 may calculate the arm target value based on the arm operation amount La, and calculate a boom target value and a bucket target value based on the arm operation amount La or the arm target value. The controller 70 may execute feedforward control to operate the boom cylinder 9, the arm cylinder 10, and the bucket cylinder 11 based on the calculated boom target value, arm target value, and bucket target value. The boom target value may be a target value for the speed of the boom 6, or may be a target value for the operating speed of the boom cylinder 9, which is a value correlated to this target value. The bucket target value may be a target value for the speed of the bucket 8, or may be a target value for the operating speed of the bucket cylinder 11, which is a value correlated to this target value.

[0050] In this case, the controller 70 may store in advance a relational expression or a map such as a look-up table that expresses the relationship between the arm operation amount La or the arm target value and the boom target value. The controller 70 may calculate the boom target value corresponding to the arm operation amount La by applying the arm operation amount La or the arm target value to the map. Similarly, the controller 70 may store in advance a relational expression or a map such as a look-up table that expresses the relationship between the arm operation amount La or the arm target value and the bucket target value. The controller 70 may calculate the bucket target value corresponding to the arm operation amount La by applying the arm operation amount La or the arm target value to the map. Then, the controller 70 inputs an arm operation command value Ia corresponding to the arm target value to the arm proportional valve (first arm proportional valve 20c or second arm proportional valve 20d), inputs a boom operation command value Ibm corresponding to the boom target value to the boom proportional valve (first boom proportional valve 20a or second boom proportional valve 20b), and inputs a bucket operation command value Ibk corresponding to the bucket target value to the bucket proportional valve (first bucket proportional valve 20e or second bucket proportional valve 20f). As a result, the arm cylinder 10, the boom cylinder 9, and the bucket cylinder 11 each operate at a speed corresponding to the arm operation amount La. In this case, the controller 70 may previously store a relational expression or a map such as a look-up table that expresses the relationship between the arm target value and the arm operation command value Ia. The controller 70 may calculate the arm operation command value Ia corresponding to the arm target value by applying the arm target value to the map. Similarly, controller 70 may store in advance a map representing the relationship between the boom target value and boom operation command value Ibm, and a map representing the relationship between the bucket target value and bucket operation command value Ibk. Controller 70 may calculate boom operation command value Ibm and bucket operation command value Ibk using these maps, the boom target value, and the bucket target value.

[0051] Of the first and second control examples described above, the first control example will be described in detail first, and then the second control example will be described in detail.

[0052] [First Control Example] In the automatic control, controller 70 calculates the arm target value corresponding to arm operation amount La, and calculates arm operation command value Ia corresponding to the arm target value. Furthermore, in the automatic control, controller 70 calculates boom operation command value Ibm so that the speed of boom 6 decreases as height deviation e decreases, and calculates bucket operation command value Ibk so that the speed of bucket 8 decreases as height deviation e decreases. Specifically, in the automatic control, controller 70 calculates boom operation command value Ibm from the following equation (1). In equation (1), Kp1 is a proportionality constant used when calculating boom operation command value Ibm. Similarly, in the automatic control, controller 70 calculates bucket operation command value Ibk from the following equation (2). In equation (2), Kp2 is a proportionality constant used when calculating bucket operation command value Ibk.

[0053] Ibm=Kp1×e...(1) Ibk=Kp2×e...(2)

[0054] From equations (1) and (2), the boom operation command value Ibm and the bucket operation command value Ibk become values ​​proportional to the deviation e. The closer the bucket 8 gets to the target construction surface, the smaller the boom operation command value Ibm and the bucket operation command value Ibk become. As a result, the closer the bucket 8 gets to the target construction surface, the lower the boom speed Vbm of the boom 6 and the bucket speed Vbk of the bucket 8, i.e., the operating speed of the boom cylinder 9 and the operating speed of the bucket cylinder 11 become. As a result, the closer the bucket 8 gets to the target construction surface, the lower the boom speed Vbm and the bucket speed Vbk become, and the bucket 8 can be moved onto the target construction surface with high precision.

[0055] Incidentally, the MC switch 28 may be switched from the ON position to the OFF position while automatic control is being executed to move the bucket 8 toward the target construction surface. If the automatic control ends at this point, it may become difficult to move the bucket 8 onto the target construction surface with precision, and it may become difficult to maintain the construction precision of the construction machine 1.

[0056] In contrast, in the present embodiment, when the MC switch 28 is switched from the ON position to the OFF position while automatic control is being executed, the controller 70 cancels the automatic control and switches to manual operation on the condition that the speed Va of the arm 7 becomes equal to or less than a predetermined speed threshold Vth. The speed threshold Vth is determined in advance experimentally or by design, and is set to a value (zero or a value close to zero) at which it can be determined that the arm 7 is in a stopped state. Note that in the present embodiment, the arm 7 is an example of a specific portion in the present disclosure, and the speed threshold Vth is an example of a specific threshold in the present disclosure.

[0057] When the MC switch 28 is switched from the on position to the off position, the controller 70 determines whether the speed Va of the arm 7 is equal to or less than the speed threshold Vth. If the speed Va of the arm 7 is higher than the speed threshold Vth, the controller 70 continues to execute the automatic control. On the other hand, if the speed Va of the arm 7 becomes equal to or less than the speed threshold Vth, the controller 70 cancels the automatic control, i.e., ends the automatic control.

[0058] As described above, automatic control is maintained until the arm 7 is stopped or until it can be determined that the arm 7 has stopped. If manual operation is switched to while the arm 7 is moving, the bucket 8 may not stop instantaneously due to the inertia of the boom 6, etc., and the bucket 8 may end up digging into the target construction surface. In contrast, because automatic control is maintained until the arm 7 is stopped, the bucket 8 is prevented from digging into the target construction surface due to the inertia of the boom 6, etc. As a result, the construction accuracy of the construction machine 1 is maintained. Furthermore, because switching to manual operation is determined based on the speed Va of the arm 7, which is directly operated by the operator, the construction accuracy of the construction machine 1 is appropriately maintained.

[0059] 3 is a flowchart illustrating the control operation when the bucket 8 is moved toward the target construction surface. This flowchart is repeatedly executed while the construction machine 1 is in operation.

[0060] First, a target construction plane is set in advance by the target construction plane setting device 30 (step S10). Next, the controller 70 determines whether the MC switch 28 has been switched to the ON position (step S20). If the MC switch 28 is in the OFF position (NO in step S20), the controller 70 outputs an arm operation command value Ia corresponding to the arm operation amount La of the arm operating member 19b, outputs a boom operation command value Ibm corresponding to the boom operation amount Lbm of the boom operating member 19a, and outputs a bucket operation command value Ibk corresponding to the bucket operation amount Lbk of the bucket operating member 19c (step S70).

[0061] On the other hand, if the MC switch 28 is in the ON position (YES in step S20), the controller 70 executes automatic control. In this case, the controller 70 calculates the height deviation e between the target construction surface and the bucket 8 (step S30). Next, the controller 70 calculates a boom operation command value Ibm and a bucket operation command value Ibk based on the height deviation e and the above-described equations (1) and (2) (step S40). The controller 70 also calculates an arm operation command value Ia based on the arm operation amount La.

[0062] Next, the controller 70 determines whether the MC switch 28 is switched to the OFF position and whether the velocity Va of the arm 7 is equal to or less than the velocity threshold Vth (step S50). If at least one of the following conditions is true: the MC switch 28 is in the ON position and the velocity Va of the arm 7 is higher than the velocity threshold Vth (NO in step S50), the controller 70 continues to execute automatic control and returns to step S30. On the other hand, if the MC switch 28 is switched to the OFF position and the velocity Va of the arm 7 is equal to or less than the velocity threshold Vth (YES in step S50), the controller 70 cancels the automatic control and sets the boom operation command value Ibm and the bucket operation command value Ibk to zero (step S60). This stops the boom 6 and the bucket 8. If the velocity Va of the arm 7 is equal to or less than the velocity threshold Vth in step S50, the velocity of the arm 7 is zero or almost zero, and the arm 7 is stopped or almost stopped. The boom 6 and the bucket 8 are also stopped by the processing of step S60 performed immediately thereafter.

[0063] [Second Control Example] Next, a second control example will be described.

[0064] When the MC switch 28 is switched to the ON position and the arm operation amount La is greater than a predetermined first threshold value Lth1, the controller 70 calculates the arm target speed Vatgt based on the following equation (3). In equation (3), Ka is a preset proportionality constant. Note that the first threshold value Lth1 is determined in advance experimentally or by design, and is set to a threshold value at which it can be determined that the operator intends to move the bucket 8. From equation (3), the arm target speed Vatgt becomes a value proportional to the arm operation amount La. The arm target speed Vatgt is an example of an arm target value in the present disclosure. The first threshold value Lth1 is an example of a first operation amount threshold in the present disclosure.

[0065] Vatgt=Ka×La...(3)

[0066] Furthermore, the controller 70 determines whether the arm operation amount La during execution of automatic control is greater than a second threshold value Lth2. The second threshold value Lth2 is a value smaller than the first threshold value Lth1. The second threshold value Lth2 is determined in advance experimentally or by design, and is set to a threshold value at which it can be determined that the operator intends to stop the arm 7. The second threshold value Lth2 is an example of a second operation amount threshold value in the present disclosure.

[0067] When the arm operation amount La is greater than the second threshold value Lth2, the controller 70 calculates a boom operation command value Ibm and a bucket operation command value Ibk based on the arm target speed Vatgt calculated by equation (3). Specifically, the controller 70 may geometrically calculate the boom operation command value Ibm using a plurality of parameters, such as information specifying the target construction surface, the dimensions of the boom 6, the dimensions of the arm 7, the dimensions of the bucket 8, the boom angle θa, the arm angle θb, and the bucket angle θc, as well as the arm target speed Vatgt. Similarly, the controller 70 may geometrically calculate the bucket operation command value Ibk using the plurality of parameters and the arm target speed Vatgt.

[0068] Specifically, for example, a target relative position that is a target for the relative position of the bucket 8 with respect to the target construction surface may be set. The target relative position may include, for example, a target attitude of the bucket 8 with respect to the target construction surface and a target distance of the tip of the bucket 8 with respect to the target construction surface. Assuming that the arm 7 operates at the arm target speed Vatgt, the controller 70 can calculate a boom target speed that is a target value for the speed of the boom 6 required for the bucket 8 to be positioned at the target relative position, and a bucket target speed that is a target value for the speed of the bucket 8 required for the bucket 8 to be positioned at the target relative position, using the multiple parameters and the arm target speed Vatgt. Then, the controller 70 calculates an arm operation command value Ia, a boom operation command value Ibm, and a bucket operation command value bk, respectively, based on the arm target speed Vatgt, the boom target speed, and the bucket target speed.

[0069] Furthermore, the controller 70 may store in advance a relational expression or a map such as a look-up table that expresses the relationship between the arm operation amount La or the arm target speed Vatgt and the boom target speed. In this case, the controller 70 may calculate the boom target speed by applying the arm operation amount La or the arm target speed Vatgt to the map. Similarly, the controller 70 may store in advance a relational expression or a map such as a look-up table that expresses the relationship between the arm operation amount La or the arm target speed Vatgt and the bucket target speed. In this case, the controller 70 may calculate the bucket target speed by applying the arm operation amount La or the arm target speed Vatgt to the map. Then, the controller 70 calculates an arm operation command value Ia, a boom operation command value Ibm, and a bucket operation command value bk, respectively, based on the arm target speed Vatgt, the boom target speed, and the bucket target speed.

[0070] The controller 70 inputs the arm operation command value Ia to the corresponding proportional valve 20 (first arm proportional valve 20c or second arm proportional valve 20d). As a result, a pilot pressure corresponding to the arm operation command value Ia is output from the proportional valve 20, and the arm 7 operates at a speed corresponding to the arm operation command value Ia. The controller 70 also inputs a boom operation command value Ibm to the corresponding proportional valve 20 (first boom proportional valve 20a or second boom proportional valve 20b). As a result, a pilot pressure corresponding to the boom operation command value Ibm is output from the proportional valve 20, and the boom 6 operates at a speed corresponding to the boom operation command value Ibm. Similarly, the controller 70 inputs a bucket operation command value Ibk to the corresponding proportional valve 20 (first bucket proportional valve 20e or second bucket proportional valve 20f). As a result, a pilot pressure corresponding to the bucket operation command value Ibk is output from the proportional valve 20, and the bucket 8 operates at a speed corresponding to the bucket operation command value Ibk.

[0071] Next, a case where the arm operation amount La is equal to or less than the second threshold Lth2 will be described. When the arm operation amount La becomes equal to or less than the second threshold Lth2 during the automatic control, the controller 70 stores the arm target speed Vatgt at the time when the arm operation amount La becomes equal to or less than the second threshold Lth2. Furthermore, when the arm operation amount La becomes equal to or less than the second threshold Lth2, the controller 70 calculates the arm target speed Vatgt so that the arm target speed Vatgt gradually decreases based on predetermined conditions. Specifically, the controller 70 reduces the arm target speed Vatgt toward zero in accordance with the elapsed time t, based on the arm target speed Vatgt at the time when the arm operation amount La becomes equal to or less than the second threshold Lth2. As a result, when the arm operation amount La becomes equal to or less than the second threshold Lth2, the arm target speed Vatgt gradually decreases toward zero. The controller 70 may gradually reduce the arm target speed Vatgt using, for example, a rate limiter. The rate limiter is a process for limiting the amount of change (decrease) in the arm target speed Vatgt per unit time to a set value (or below the set value). In this case, the predetermined condition is a condition for limiting the amount of change (decrease) in the arm target speed Vatgt per unit time to a set value (or below the set value).

[0072] Furthermore, the controller 70 may geometrically calculate the boom operation command value Ibm and the bucket operation command value Ibk based on the arm target speed Vatgt, which gradually decreases based on the predetermined condition. The geometric calculation method is as described above. As a result, the boom speed Vbm and the bucket speed Vbk gradually decrease.

[0073] Furthermore, the controller 70 constantly determines whether the arm speed Va or the target speed Vatgt of the arm 7 has become equal to or less than a predetermined speed threshold Vth. The speed threshold Vth is set to a value that allows it to be determined that the arm 7 is stopped. When the arm operation amount La is greater than the second threshold Lth2, the arm speed Va and the target speed Vatgt will basically be higher than the speed threshold Vth. In this case, the controller 70 continues to execute automatic control.

[0074] On the other hand, when the arm operation amount La becomes equal to or less than the second threshold value Lth2, the target speed Vatgt decreases in accordance with the elapsed time t, and the arm speed Va and the arm target speed Vatgt become equal to or less than the speed threshold value Vth at some point. The controller 70 cancels the automatic control on the condition that the arm speed Va or the arm target speed Vatgt is equal to or less than the speed threshold value Vth. Furthermore, the controller 70 sets the boom operation command value Ibm and the bucket operation command value Ibk to zero, and stops the work device 4.

[0075] When the boom operation command value Ibm and the bucket operation command value Ibk are calculated based on the arm operation amount La, if automatic control is released the moment the arm operation amount La becomes zero, the work implement 4 may not be stopped instantaneously due to the inertia of the boom 6, etc. As a result, the bucket 8 may dig into the target construction surface, which could deteriorate the construction accuracy of the construction machine 1. In contrast, when the arm operation amount La becomes equal to or less than the second threshold value Lth2 and it is determined that the operator intends to stop the work implement 4, the arm target speed Vatgt gradually decreases, which gradually reduces the boom speed Vbm and the bucket speed Vbk. As a result, when the arm operation amount La becomes zero, the work implement 4 can be stopped instantaneously, the bucket 8 will no longer dig into the target construction surface, and the construction accuracy of the construction machine 1 can be maintained.

[0076] 4 is a flowchart illustrating the control operation when moving the bucket 8 to a target construction surface in this embodiment. The controller 70 repeatedly executes the processing shown in this flowchart while the construction machine 1 is in operation.

[0077] First, a target construction plane is set in advance by the target construction plane setting device 30 (step S100). Next, the controller 70 determines whether the MC switch 28 is switched to the ON position and whether the arm operation amount La is greater than the first threshold value Lth1 (step S110). If at least one of the following conditions is met: the MC switch 28 is in the OFF position; and the arm operation amount La is equal to or less than the first threshold value Lth1 (NO in step S110), the controller 70 outputs a boom operation command value Ibm based on the boom operation amount Lbm of the boom operation member 19a. Similarly, the controller 70 outputs a bucket operation command value Ibk based on the bucket operation amount Lbk of the bucket operation member 19c (step S180). In this case, the controller 70 also outputs an arm operation command value Ia based on the arm operation amount La of the arm operation member 19b.

[0078] On the other hand, when the MC switch 28 is switched to the ON position and the arm operation amount La is greater than the first threshold value Lth1 (YES in step S110), the controller 70 calculates the arm target speed Vatgt using the above-mentioned equation (3) (step S120).

[0079] Next, controller 70 determines whether arm operation amount La is greater than second threshold value Lth2 (step S130). If arm operation amount La is greater than second threshold value Lth2 (YES in step S130), controller 70 geometrically calculates boom operation command value Ibm and bucket operation command value Ibk based on arm target speed Vatgt, as described above (step S150).

[0080] On the other hand, if the arm operation amount La is equal to or less than the second threshold value Lth2 (NO in S130), the controller 70 reduces the arm target speed Vatgt in accordance with the elapsed time t, using the arm target speed Vatgt at the moment the arm operation amount La becomes equal to or less than the second threshold value Lth2 as a reference (step S140). As a result, the arm target speed Vatgt gradually decreases in accordance with the elapsed time t. Next, the controller 70 geometrically calculates the boom operation command value Ibm and the bucket operation command value Ibk based on the calculated arm target speed Vatgt (step S150). At this time, as the arm target speed Vatgt gradually decreases, the boom operation command value Ibm and the bucket operation command value Ibk gradually decrease toward zero. As a result, the boom speed Vbm and the bucket speed Vbk gradually decrease.

[0081] After the boom operation command value Ibm and the bucket operation command value Ibk are calculated in step S150, the controller 70 determines whether the arm speed Va or the arm target speed Vatgt has become equal to or less than the speed threshold value Vth (step S160). If the arm speed Va or the arm target speed Vatgt is higher than the speed threshold value Vth (NO in step S160), the controller 70 returns to step S130 and continues to execute automatic control. As a result, automatic control continues to be executed until the arm speed Va or the arm target speed Vatgt becomes equal to or less than the speed threshold value Vth, thereby maintaining the construction accuracy of the construction machine 1.

[0082] On the other hand, if arm speed Va or arm target speed Vatgt becomes equal to or less than speed threshold value Vth (YES in step S160), controller 70 cancels the automatic control and sets boom operation command value Ibm and bucket operation command value Ibk to zero (step S170), thereby allowing working implement 4 to stop without shock.

[0083] [Modification] In the above embodiment, automatic control is switched on and off by the MC switch 28. In addition to this, automatic control may be switched on and off by turning an emergency stop button on and off. Specifically, when the emergency stop button is turned on while automatic control is being executed, automatic control may be released on the condition that the speed Va of the arm 7 or the arm target speed Vatgt is equal to the speed threshold value Vth1. In this case, the operation of turning the emergency stop button on is an example of the operation of switching the switching device of the present disclosure from the on position to the off position.

[0084] In the above embodiment, the boom 6 and the bucket 8 are automatically controlled based on the arm operation amount La of the arm 7, but the arm 7 and the bucket 8 may also be automatically controlled based on the boom operation amount Lbm of the boom 6. In this case, the controller 70 determines whether to cancel the automatic control based on the boom speed Vbm of the boom 6. Alternatively, the boom 6 and the arm 7 may also be automatically controlled based on the bucket operation amount Lbk of the bucket 8. In this case, the controller 70 determines whether to cancel the automatic control based on the bucket speed Vbk of the bucket 8.

[0085] In the above embodiment, P control using equations (1) and (2) was exemplified as the feedback control in the first control example, but the feedback control may be PI control, PD control, or PID control.

[0086] In the above embodiment, the specific part is an arm, but the specific part may be, for example, a boom.

[0087] In the above embodiment, the construction machine control device is provided on the construction machine 1, but the construction machine control device in the present disclosure does not necessarily have to be provided on the construction machine, and may be located at a location remote from the construction machine. In this case, the construction machine control device and the construction machine are configured to be able to send and receive information via a network such as the Internet or a mobile phone network.

[0088] [Summary of the present disclosure] A construction machine control device for a construction machine according to a first aspect of the present disclosure is a control device for a construction machine equipped with a work device including a boom, an arm rotatably connected to the tip of the boom, and a tip attachment rotatably connected to the tip of the arm, and the construction machine control device comprises a controller that executes automatic control of the work device to move the tip attachment toward a predetermined target construction surface, and the controller continues the automatic control until the speed of a specific part of the work device or a specific value that is a value correlated to this speed becomes equal to or less than a specific threshold that is a threshold for determining whether to stop the operation of the work device.

[0089] According to the first aspect, the controller continues the automatic control until the specific value (i.e., the speed of a specific part of the work device or a value correlated to this speed) becomes equal to or less than the specific threshold, which is a threshold for determining whether to stop the operation of the work device, so that the end attachment can be moved close to the target construction surface with high accuracy. This makes it possible to prevent the end attachment from exceeding the target construction surface, in other words, to prevent the end attachment from passing over the target construction surface, making it easier to maintain the construction accuracy of the construction surface.

[0090] It is preferable that the construction machine control device according to the second aspect further comprises the following feature in addition to the construction machine control device according to the first aspect: The construction machine control device according to the second aspect comprises an arm operating member that receives arm operation by an operator to move the arm, the specific part is the arm, the specific value is the speed of the arm or an arm specific value that is a value correlated to this speed, the controller is configured to control the movement of the arm, the movement of the boom and the movement of the tip attachment based on the arm operation in the automatic control, and the controller terminates the automatic control when the arm specific value becomes equal to or less than the specific threshold value.

[0091] In a second aspect, the arm specific value (i.e., the arm speed or a value correlated to this speed), which is an output as a result of control based on the arm operation by the operator, is included in the conditions for terminating the automatic control. If the arm specific value is greater than the specific threshold as a result of the operator continuing the arm operation, the automatic control continues, and if the arm specific value becomes equal to or less than the specific threshold as a result of the operator ceasing the arm operation, the automatic control terminates. That is, in the second aspect, the operator can continue the automatic control while performing the arm operation, and this automatic control can move the tip attachment accurately close to the target construction surface.

[0092] A construction machine control device according to a third aspect is preferably the construction machine control device according to the second aspect, further comprising the following configuration: In the third aspect, in the automatic control, the controller calculates an arm operation command value, which is a command value for moving the arm, based on the operation amount of the arm operation, and calculates a boom operation command value, which is a command value for moving the boom, so that the speed of the boom decreases as the height deviation, which is the deviation between the height of the target construction surface and the height of the tip attachment, decreases.

[0093] In the third aspect, in the automatic control, the speed of the boom decreases as the height deviation decreases, i.e., as the tip attachment approaches the target construction surface, so the operator can more easily time the end of the arm operation when the tip attachment moves close to the target construction surface. This makes it possible to move the tip attachment closer to the target construction surface with even greater accuracy in the automatic control.

[0094] In this third aspect, the controller may calculate not only the boom operation command value but also a tip attachment operation command value, which is a command value for moving the tip attachment, so that the speed of the tip attachment decreases as the height deviation decreases.

[0095] The construction machine control device according to the fourth aspect is preferably the construction machine control device according to the first aspect, further comprising the following features. That is, the construction machine control device according to the fourth aspect further includes an arm operating member that receives arm operation by an operator to move the arm, the specific part is the arm, the specific value is an arm specific value that is the arm speed or a value correlated to this speed, or a target value of the arm speed or an arm target value that is a value correlated to this target value, the controller executes the automatic control when the operation amount of the arm operation is greater than a predetermined first operation amount threshold, the controller, in the automatic control, calculates the arm target value based on the operation amount of the arm operation, and calculates the target value of the boom speed or a boom target value that is a value correlated to this target value, based on the operation amount of the arm operation or the arm target value, the controller, in the automatic control, calculates the arm target value so that the arm target value gradually decreases based on predetermined conditions when the operation amount of the arm operation becomes equal to or less than a second operation amount threshold that is smaller than the first operation amount threshold, and terminates the automatic control when the arm specific value or the arm target value becomes equal to or less than the specific threshold.

[0096] As in the fourth aspect, the controller may perform feedforward control by calculating the arm target value based on the operation amount of the arm operation and calculating the boom target value based on the operation amount of the arm operation or the arm target value. With such feedforward control, the arm and the boom may not be able to stop instantly due to inertia even when the operation amount of the arm operation becomes zero. Therefore, in this fourth aspect, the arm target value is calculated so that the arm target value gradually decreases based on a predetermined condition when the operation amount of the arm operation becomes equal to or less than a second operation amount threshold that is smaller than the first operation amount threshold. In this case, when the operation amount of the arm operation becomes equal to or less than the second operation amount threshold, the arm target value gradually decreases, and the boom target value also gradually decreases. This makes it possible to suppress the arm speed and the boom speed to relatively small values ​​when the operation amount of the arm operation becomes even smaller than the second operation amount threshold and reaches zero. Therefore, the arm and the boom can be stopped at a relatively early stage after the operation amount of the arm operation becomes equal to or less than zero. This prevents the tip attachment from going beyond the target construction surface, in other words, preventing the tip attachment from passing over the target construction surface, making it easier to maintain the construction accuracy of the construction surface.

[0097] In this fourth aspect, the controller may, in the feedforward control, calculate not only the boom target value but also a target value for the speed of the tip attachment or a tip attachment target value that is a value correlated to this target value, using the operation amount of the arm operation or the arm target value.

[0098] A construction machine according to a fifth aspect includes the work implement and the construction machine control device according to any one of the first to fourth aspects.

[0099] According to the fifth aspect, the controller continues the automatic control until the specific value becomes equal to or less than the specific threshold value, which is a threshold value for determining whether to stop the operation of the work device, so that the end attachment can be moved close to the target construction surface with high accuracy. This makes it possible to prevent the end attachment from exceeding the target construction surface, in other words, to prevent the end attachment from passing over the target construction surface, making it easier to maintain the construction accuracy of the construction surface.

Claims

1. A construction machine control device for a construction machine equipped with a working device including a boom, an arm rotatably connected to the tip of the boom, and a tip attachment rotatably connected to the tip of the arm, comprising a controller that executes automatic control of the working device to move the tip attachment toward a predetermined target construction surface, and the controller continues the automatic control until the speed of a specific part of the working device or a specific value that is a value correlated to this speed becomes equal to or less than a specific threshold that is a threshold for determining whether the operation of the working device should be stopped.

2. A construction machine control device as described in claim 1, comprising an arm operating member that receives arm operation by an operator to move the arm, wherein the specific part is the arm, and the specific value is an arm specific value that is the speed of the arm or a value correlated to this speed, wherein the controller is configured to control the movement of the arm, the movement of the boom, and the movement of the tip attachment based on the arm operation in the automatic control, and wherein the controller terminates the automatic control when the arm specific value becomes equal to or less than the specific threshold value.

3. A construction machine control device as described in claim 2, wherein the controller, in the automatic control, calculates an arm operation command value, which is a command value for moving the arm, based on the amount of operation of the arm, and calculates a boom operation command value, which is a command value for moving the boom, so that the speed of the boom decreases as the height deviation, which is the deviation between the height of the target construction surface and the height of the tip attachment, decreases.

4. A construction machine control device as described in claim 1, further comprising an arm operating member that receives arm operation by an operator to move the arm, wherein the specific part is the arm, and the specific value is an arm specific value that is the arm speed or a value correlated to this speed, or a target value for the arm speed or an arm target value that is a value correlated to this target value, and wherein the controller executes the automatic control when the operation amount of the arm operation is greater than a predetermined first operation amount threshold, and wherein the controller, in the automatic control, calculates the arm target value based on the operation amount of the arm operation, and calculates the target value for the boom speed or a boom target value that is a value correlated to this target value, based on the operation amount of the arm operation or the arm target value, and wherein the controller, in the automatic control, calculates the arm target value so that the arm target value gradually decreases based on a predetermined condition when the operation amount of the arm operation becomes equal to or less than a second operation amount threshold that is smaller than the first operation amount threshold, and terminates the automatic control when the arm specific value or the arm target value becomes equal to or less than the specific threshold.

5. A construction machine comprising the work implement and the construction machine control device according to any one of claims 1 to 4.

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