Work machine, and remote control system of work machine

Abstract

To aim to assist in understanding underground conditions.SOLUTION: A work machine includes: a lower running body; an upper rotating body rotatably mounted on the lower running body; an attachment attached to the upper rotating body; a sensor attached to the upper rotating body; and a control device calculating an excavation reaction force generated by an excavation operation based on the output of the sensor each time the excavation operation is performed, and when a way in which the excavation reaction force changes satisfies specified conditions, outputting a notification indicating that underground conditions around the ground surface where excavation is performed by the excavation operation are different from underground conditions in other parts of the ground surface.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to a working machine and a remote operation system for a working machine.

Background Art

[0002] Conventionally, there is known an excavator in which a working part such as an arm including an actuator feeds back a working reaction force received from a work object or the like on which the work is performed to an operator via an operation part that sends a command to the working part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described conventional technology, for example, it is possible to feed back the excavation reaction force in the excavation operation to the operator. However, in the conventional technology, for example, when there is an embedded object under the excavation surface, it is difficult for the operator to grasp the existence of the embedded object and the possibility of damaging the embedded object due to the excavation operation. That is, in the above-described conventional technology, it is difficult for the operator to grasp the underground state.

[0005] An object of the present disclosure is to assist in grasping the underground state.

Means for Solving the Problems

[0006] The construction machine according to an embodiment of the present invention includes a lower traveling body, an upper revolving body rotatably mounted on the lower traveling body, an attachment attached to the upper revolving body, a sensor attached to the upper revolving body, and a control device that calculates, each time the excavation operation is performed, the excavation reaction force generated by the excavation operation based on the output of the sensor, and outputs a notification indicating that the underground state around the ground where the excavation operation is being performed is different from the underground state of other ground when the manner of change of the excavation reaction force satisfies a predetermined condition.

[0007] The remote operation system of the construction machine according to an embodiment of the present invention is a remote operation system of a construction machine including a lower traveling body, an upper revolving body rotatably mounted on the lower traveling body, an attachment attached to the upper revolving body, a sensor attached to the upper revolving body, and an external device that supports remote operation of the construction machine. The external device has a control device that calculates, each time the excavation operation is performed, the excavation reaction force generated by the excavation operation based on the output of the sensor, and outputs a notification indicating that the underground state around the ground where the excavation operation is being performed is different from the underground state of other ground when the manner of change of the excavation reaction force satisfies a predetermined condition.

Advantages of the Invention

[0008] It is possible to assist in grasping the underground state.

Brief Description of the Drawings

[0009]

Figure 1A

Figure 1B

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0010] (First Embodiment) First, with reference to FIGS. 1A and 1B, an excavator 100 as a construction machine according to an embodiment of the present invention will be described. FIG. 1A is a side view of the excavator 100, and FIG. 1B is a top view of the excavator 100.

[0011] In the present embodiment, the lower traveling body 1 of the excavator 100 includes crawlers 1C. The crawlers 1C are driven by a traveling hydraulic motor 2M mounted on the lower traveling body 1. Specifically, the crawlers 1C include a left crawler 1CL and a right crawler 1CR. The left crawler 1CL is driven by a left traveling hydraulic motor 2ML, and the right crawler 1CR is driven by a right traveling hydraulic motor 2MR.

[0012] The upper slewing body 3 is mounted on the lower traveling body 1 via a slewing mechanism 2 so as to be slewing - capable. The slewing mechanism 2 is driven by a slewing hydraulic motor 2A mounted on the upper slewing body 3. However, the slewing hydraulic motor 2A may be a slewing motor - generator as an electric actuator.

[0013] A boom 4 is attached to the upper slewing body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 as an end attachment is attached to the tip of the arm 5. The boom 4, the arm 5, and the bucket 6 constitute an excavation attachment AT which is an example of an attachment. The boom 4 is driven by a boom cylinder 7, the arm 5 is driven by an arm cylinder 8, and the bucket 6 is driven by a bucket cylinder 9.

[0014] The boom 4 is rotatably supported by the upper slewing body 3. And a boom angle sensor S1 is attached to the boom 4. The boom angle sensor S1 can detect a boom angle β1 which is the rotation angle of the boom 4. The boom angle β1 is, for example, the rising angle from the state where the boom 4 is lowered most. Therefore, the boom angle β1 becomes maximum when the boom 4 is raised most.

[0015] The arm 5 is rotatably supported with respect to the boom 4. And an arm angle sensor S2 is attached to the arm 5. The arm angle sensor S2 can detect an arm angle β2 which is the rotation angle of the arm 5. The arm angle β2 is, for example, the opening angle from the state where the arm 5 is closed most. Therefore, the arm angle β2 becomes maximum when the arm 5 is opened most.

[0016] The bucket 6 is rotatably supported with respect to the arm 5 by a bucket link mechanism 6a. And a bucket angle sensor S3 is attached to the bucket 6. The bucket angle sensor S3 can detect a bucket angle β3 which is the rotation angle of the bucket 6. The bucket angle β3 is the opening angle from the state where the bucket 6 is closed most. Therefore, the bucket angle β3 becomes maximum when the bucket 6 is opened most.

[0017] In the embodiments shown in FIGS. 1A and 1B, each of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 is composed of a combination of an acceleration sensor and a gyro sensor. However, at least one of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 may be composed of only an acceleration sensor. Further, the boom angle sensor S1 may be a stroke sensor attached to the boom cylinder 7, or may be a rotary encoder, a potentiometer, an inertial measurement device, or the like. The same applies to the arm angle sensor S2 and the bucket angle sensor S3.

[0018] The upper slewing body 3 is provided with a cabin 10 as an operator's cab, and a power source such as an engine 11 is mounted thereon. Further, an object detection device 70, an imaging device 80, a machine body inclination sensor S4, a slewing angular velocity sensor S5, etc. are attached to the upper slewing body 3. Inside the cabin 10, an operation device 26, a controller 30, a display device D1, a sound output device D2, etc. are provided. In this document, for convenience, the side of the upper slewing body 3 where the excavation attachment AT is attached is defined as the front, and the side where the counterweight is attached is defined as the rear.

[0019] The object detection device 70 is an example of a surrounding monitoring device, and is configured to detect an object existing around the excavator 100. The object is, for example, a person, an animal, a vehicle, a construction machine, a building, a wall, a fence, or a hole. The object detection device 70 is, for example, a camera, an ultrasonic sensor, a millimeter wave radar, a stereo camera, a LIDAR, a distance image sensor, or an infrared sensor. In the present embodiment, the object detection device 70 includes a front sensor 70F attached to the front end of the upper surface of the cabin 10, a rear sensor 70B attached to the rear end of the upper surface of the upper slewing body 3, a left sensor 70L attached to the left end of the upper surface of the upper slewing body 3, and a right sensor 70R attached to the right end of the upper surface of the upper slewing body 3.

[0020] The object detection device 70 may be configured to detect a predetermined object within a predetermined area set around the excavator 100. The object detection device 70 may be configured to distinguish between a person and an object other than a person. The object detection device 70 may be configured to calculate the distance to an object recognized from the object detection device 70 or the excavator 100.

[0021] The imaging device 80 is another example of a surrounding monitoring device and images the surroundings of the excavator 100. In the present embodiment, the imaging device 80 includes a rear camera 80B attached to the rear end of the upper surface of the upper swing body 3, a left camera 80L attached to the left end of the upper surface of the upper swing body 3, and a right camera 80R attached to the right end of the upper surface of the upper swing body 3. The imaging device 80 may include a front camera.

[0022] The rear camera 80B is arranged adjacent to the rear sensor 70B, the left camera 80L is arranged adjacent to the left sensor 70L, and the right camera 80R is arranged adjacent to the right sensor 70R. When the imaging device 80 includes a front camera, the front camera may be arranged adjacent to the front sensor 70F.

[0023] The image captured by the imaging device 80 is displayed on the display device D1. The imaging device 80 may be configured to display a viewpoint conversion image such as an aerial view image on the display device D1. The aerial view image is generated, for example, by synthesizing the images output by the rear camera 80B, the left camera 80L, and the right camera 80R respectively.

[0024] The body tilt sensor S4 is configured to detect the tilt of the upper swing body 3 with respect to a predetermined plane. In the present embodiment, the body tilt sensor S4 is an acceleration sensor that detects the tilt angle (roll angle) around the front-rear axis and the tilt angle (pitch angle) around the left-right axis of the upper swing body 3 with respect to the horizontal plane. The front-rear axis and the left-right axis of the upper swing body 3 pass through, for example, a point on the swing axis of the excavator 100, the excavator center point, which are orthogonal to each other. The body tilt sensor S4 may be configured as a combination of an acceleration sensor and a gyro sensor.

[0025] The turning angular velocity sensor S5 is configured to detect the turning angular velocity of the upper slewing body 3. In this embodiment, the turning angular velocity sensor S5 is a gyro sensor. The turning angular velocity sensor S5 may be a resolver, a rotary encoder, or the like. The turning angular velocity sensor S5 may detect the turning speed. The turning speed may be calculated from the turning angular velocity.

[0026] Hereinafter, each of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine body inclination sensor S4, and the turning angular velocity sensor S5 is also referred to as an attitude detection device.

[0027] The display device D1 is configured to display various information. The sound output device D2 is configured to output sound.

[0028] The operating device 26 is a device used by the operator for operating the actuator. Further, the operating device 26 of this embodiment has a force feedback device 90 attached thereto. The force feedback device 90 feeds back the excavation reaction force to the operator via the operating device 26 according to, for example, the excavation reaction force calculated in the controller 30.

[0029] More specifically, the force feedback device 90 increases the force required to tilt the operating lever included in the operating device 26 or vibrates the operating lever according to the excavation reaction force input from the controller 30. Further, the force feedback device 90 may shake the driver's seat provided in the cabin 10 according to, for example, the excavation reaction force.

[0030] The controller 30 is a control device for controlling the excavator 100. In the present embodiment, the controller 30 is composed of a computer including a CPU, a volatile memory device, a non-volatile memory device, and the like. Then, the controller 30 reads out and executes a program corresponding to each function from the non-volatile memory device. Each function includes, for example, a machine guidance function for guiding (guiding) the manual operation of the excavator 100 by the operator, and a machine control function for automatically assisting the manual operation of the excavator 100 by the operator.

[0031] In addition, the controller 30 of the present embodiment calculates the excavation reaction force when the excavator 100 performs an excavation operation and outputs it to the force feedback device 90. Further, when the manner of change of the excavation reaction force during the excavation operation satisfies a predetermined condition, the controller 30 of the present embodiment outputs a notification to the operator indicating that the underground state of the ground around the excavation position is different from the underground state of other ground. The state where the underground state of the ground around the excavation position is different from the underground state of other ground in the present embodiment includes a state where there is an embedded object in the ground around the excavation position, a state where there is a cavity in the ground around the excavation position, and a state where there is an object softer than the ground in the ground around the excavation position.

[0032] In the present embodiment, the notification indicating that the underground state is different may include, for example, a message instructing the stop of the excavation operation and a message prompting the confirmation of the underground state. Further, other ground may include the ground where the excavation work has already been performed.

[0033] In the present embodiment, the predetermined condition specifically may include, for example, becoming rapidly larger or becoming rapidly smaller. In other words, the case where the manner of change of the excavation reaction force satisfies a predetermined condition may include the case where the excavation reaction force changes by a certain width or more (becomes larger or becomes smaller) within a predetermined time.

[0034] When the excavation reaction force changes (increases) by a certain width or more within a predetermined time, for example, it is the case when the tip of the bucket 6 contacts an embedded object existing in the ground where excavation is being carried out, or when the tip of the bucket 6 approaches an embedded object existing in the ground where excavation is being carried out. Also, when the excavation reaction force changes (decreases) by a certain width or more within a predetermined time, for example, it is the case when there is a cavity in the ground where excavation is being carried out, or when there is a softer object than the ground, or when an embedded object in the ground is destroyed. In this embodiment, by setting such predetermined conditions, the operator can be made to infer what the tip of the bucket 6 has contacted in the ground.

[0035] In this embodiment, the predetermined condition may be a tendency to increase exponentially. When the excavation reaction force has a tendency to increase exponentially, it indicates that the ground hit by the tip of the bucket 6 is changing steeply and becoming hard. In this embodiment, by setting such predetermined conditions, for example, the operator can be made to grasp the possibility that the tip of the bucket 6 is approaching an embedded object.

[0036] In this embodiment, in this way, from the change in the excavation reaction force, it is detected that the state of the ground where excavation is being carried out has changed, and the operator of the excavator 100 is notified to that effect. Therefore, according to this embodiment, the operator can be made to perform an operation considering the state of the ground.

[0037] Also, according to this embodiment, a force sensation corresponding to the excavation reaction force is fed back to the operator. For this reason, according to this embodiment, the operator can be made to feel the load on the excavator 100 as a force sensation, and the operator can be prompted to avoid operations with a high load. For this reason, in this embodiment, the load on the excavator 100 can be reduced, and the work efficiency can be improved.

[0038] Details of the functions of the controller 30 of this embodiment will be described later.

[0039] In the following description, the force feedback device 90 is assumed to be provided in the operating device 26, but it is not limited thereto. The force feedback device 90 may be mounted on, for example, the hand of an operator who operates the excavator 100. In that case, the force feedback device 90 may communicate with the controller 30 and acquire information indicating the excavation reaction force calculated by the controller 30.

[0040] In addition, the excavation reaction force on the excavator 100 in the present embodiment is an example of the working reaction force on the working machine.

[0041] Next, referring to FIG. 2, another configuration example of the hydraulic system mounted on the excavator 100 will be described. FIG. 2 is a diagram showing another configuration example of the hydraulic system mounted on the excavator 100. In FIG. 2, the mechanical power transmission system, the hydraulic oil line, the pilot line, and the electric control system are shown by double lines, solid lines, broken lines, and dotted lines, respectively.

[0042] The hydraulic system in FIG. 2 mainly includes an engine 11, a regulator 13, a main pump 14, a pilot pump 15, a control valve 17, an operating device 26, a discharge pressure sensor 28, an operating pressure sensor 29, a controller 30, and the like.

[0043] In FIG. 2, the hydraulic system circulates hydraulic oil from the main pump 14 driven by the engine 11 to the hydraulic oil tank through the center bypass pipeline 40 or the parallel pipeline 42.

[0044] The engine 11 is a drive source of the excavator 100. In the present embodiment, the engine 11 is, for example, a diesel engine that operates to maintain a predetermined rotational speed. The output shaft of the engine 11 is connected to the input shafts of the main pump 14 and the pilot pump 15.

[0045] The main pump 14 supplies hydraulic oil to the control valve 17 through the hydraulic oil line. In the present embodiment, the main pump 14 is a swash plate type variable displacement hydraulic pump.

[0046] The regulator 13 controls the discharge amount of the main pump 14. In the present embodiment, the regulator 13 controls the discharge amount of the main pump 14 by adjusting the swash plate tilt angle of the main pump 14 according to a control command from the controller 30.

[0047] The pilot pump 15 is configured to supply hydraulic oil to a hydraulic control device including the operating device 26 via a pilot line. In the present embodiment, the pilot pump 15 is a fixed displacement hydraulic pump. However, the pilot pump 15 may be omitted. In this case, the function performed by the pilot pump 15 may be realized by the main pump 14. That is, the main pump 14 may have a function of supplying hydraulic oil to the operating device 26 etc. after reducing the pressure of the hydraulic oil by a throttle or the like, in addition to the function of supplying hydraulic oil to the control valve 17.

[0048] The control valve 17 is a hydraulic control device that controls the hydraulic system in the excavator 100. In the present embodiment, the control valve 17 includes control valves 171 to 176. The control valve 175 includes a control valve 175L and a control valve 175R, and the control valve 176 includes a control valve 176L and a control valve 176R. The control valve 17 can selectively supply the hydraulic oil discharged by the main pump 14 to one or a plurality of hydraulic actuators through the control valves 171 to 176. The control valves 171 to 176 control the flow rate of the hydraulic oil flowing from the main pump 14 to the hydraulic actuator and the flow rate of the hydraulic oil flowing from the hydraulic actuator to the hydraulic oil tank. The hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left travel hydraulic motor 2ML, a right travel hydraulic motor 2MR, and a swing hydraulic motor 2A.

[0049] The operating device 26 is a device used by an operator for operating the actuator. The actuator includes at least one of a hydraulic actuator and an electric actuator. In this embodiment, the operating device 26 supplies the hydraulic oil discharged from the pilot pump 15 to the pilot ports of the corresponding control valves in the control valve 17 via a pilot line. The pressure of the hydraulic oil (pilot pressure) supplied to each of the pilot ports is a pressure corresponding to the operating direction and operating amount of the operating device 26 corresponding to each of the hydraulic actuators. However, the operating device 26 may be an electric control type instead of the pilot pressure type as described above. In this case, the control valve in the control valve 17 may be an electromagnetic solenoid type spool valve.

[0050] The discharge pressure sensor 28 detects the discharge pressure of the main pump 14. In this embodiment, the discharge pressure sensor 28 outputs the detected value to the controller 30.

[0051] The operating pressure sensor 29 detects the content of the operation of the operating device 26 by the operator. In this embodiment, the operating pressure sensor 29 detects the operating direction and operating amount of the lever or pedal of the operating device 26 corresponding to each actuator in the form of pressure (operating pressure), and outputs the detected value to the controller 30. The content of the operation of the operating device 26 may be detected using other sensors other than the operating pressure sensor.

[0052] The main pump 14 includes a left main pump 14L and a right main pump 14R. The left main pump 14L circulates the hydraulic oil to the hydraulic oil tank via the left center bypass line 40L or the left parallel line 42L, and the right main pump 14R circulates the hydraulic oil to the hydraulic oil tank via the right center bypass line 40R or the right parallel line 42R.

[0053] The left center bypass pipeline 40L is a hydraulic oil line that passes through the control valves 171, 173, 175L, and 176L arranged within the control valve 17. The right center bypass pipeline 40R is a hydraulic oil line that passes through the control valves 172, 174, 175R, and 176R arranged within the control valve 17.

[0054] The control valve 171 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged from the left main pump 14L to the left travel hydraulic motor 2ML and to discharge the hydraulic oil discharged from the left travel hydraulic motor 2ML to the hydraulic oil tank.

[0055] The control valve 172 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged from the right main pump 14R to the right travel hydraulic motor 2MR and to discharge the hydraulic oil discharged from the right travel hydraulic motor 2MR to the hydraulic oil tank.

[0056] The control valve 173 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged from the left main pump 14L to the slewing hydraulic motor 2A and to discharge the hydraulic oil discharged from the slewing hydraulic motor 2A to the hydraulic oil tank.

[0057] The control valve 174 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged from the right main pump 14R to the bucket cylinder 9 and to discharge the hydraulic oil within the bucket cylinder 9 to the hydraulic oil tank.

[0058] The control valve 175L is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged from the left main pump 14L to the boom cylinder 7. The control valve 175R is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged from the right main pump 14R to the boom cylinder 7 and to discharge the hydraulic oil within the boom cylinder 7 to the hydraulic oil tank.

[0059] The control valve 176L is a spool valve that supplies the hydraulic oil discharged by the left main pump 14L to the arm cylinder 8 and switches the flow of the hydraulic oil to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0060] The control valve 176R is a spool valve that supplies the hydraulic oil discharged by the right main pump 14R to the arm cylinder 8 and switches the flow of the hydraulic oil to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0061] The left parallel pipeline 42L is a hydraulic oil line parallel to the left center bypass pipeline 40L. When the flow of the hydraulic oil passing through the left center bypass pipeline 40L is restricted or blocked by any one of the control valves 171, 173, 175L, the left parallel pipeline 42L can supply the hydraulic oil to the downstream control valve. The right parallel pipeline 42R is a hydraulic oil line parallel to the right center bypass pipeline 40R. When the flow of the hydraulic oil passing through the right center bypass pipeline 40R is restricted or blocked by any one of the control valves 172, 174, 175R, the right parallel pipeline 42R can supply the hydraulic oil to the downstream control valve.

[0062] The regulator 13 includes a left regulator 13L and a right regulator 13R. The left regulator 13L controls the discharge amount of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L according to the discharge pressure of the left main pump 14L. Specifically, for example, the left regulator 13L adjusts the swash plate tilt angle of the left main pump 14L in response to an increase in the discharge pressure of the left main pump 14L to reduce the discharge amount. The same applies to the right regulator 13R. This is to ensure that the absorbed horsepower of the main pump 14, which is represented by the product of the discharge pressure and the discharge amount, does not exceed the output horsepower of the engine 11.

[0063] The operating device 26 includes a left operating lever 26L, a right operating lever 26R, and a traveling lever 26D. The traveling lever 26D includes a left traveling lever 26DL and a right traveling lever 26DR.

[0064] The left operation lever 26L is used for slewing operation and the operation of the arm 5. When the left operation lever 26L is operated in the front-rear direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 176. When it is operated in the left-right direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 173.

[0065] Specifically, when the left operation lever 26L is operated in the arm closing direction, it introduces hydraulic oil into the right pilot port of the control valve 176L and also into the left pilot port of the control valve 176R. When the left operation lever 26L is operated in the arm opening direction, it introduces hydraulic oil into the left pilot port of the control valve 176L and also into the right pilot port of the control valve 176R. When the left operation lever 26L is operated in the left slewing direction, it introduces hydraulic oil into the left pilot port of the control valve 173, and when it is operated in the right slewing direction, it introduces hydraulic oil into the right pilot port of the control valve 173.

[0066] Also, a force feedback device 90L for presenting a force sensation corresponding to the excavation reaction force is provided on the left operation lever 26L.

[0067] The right operation lever 26R is used for the operation of the boom 4 and the operation of the bucket 6. When the right operation lever 26R is operated in the front-rear direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 175. When it is operated in the left-right direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 174.

[0068] Specifically, when the right operation lever 26R is operated in the boom lowering direction, hydraulic oil is introduced into the left pilot port of the control valve 175R. Also, when the right operation lever 26R is operated in the boom raising direction, hydraulic oil is introduced into the right pilot port of the control valve 175L and also into the left pilot port of the control valve 175R. Further, when the right operation lever 26R is operated in the bucket closing direction, hydraulic oil is introduced into the right pilot port of the control valve 174, and when it is operated in the bucket opening direction, hydraulic oil is introduced into the left pilot port of the control valve 174.

[0069] Also, a force feedback device 90R for presenting a force feedback corresponding to the excavation reaction force is provided on the right operation lever 26R.

[0070] The travel lever 26D is used to operate the crawler 1C. Specifically, the left travel lever 26DL is used to operate the left crawler 1CL. It may be configured to be interlocked with the left travel pedal. When the left travel lever 26DL is operated in the front-rear direction, it uses the hydraulic oil discharged from the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 171. Also, a force feedback device 90DL for presenting a force feedback corresponding to the excavation reaction force is provided on the left travel lever 26DL.

[0071] The right travel lever 26DR is used to operate the right crawler 1CR. It may be configured to be interlocked with the right travel pedal. When the right travel lever 26DR is operated in the front-rear direction, it uses the hydraulic oil discharged from the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 172. Also, a force feedback device 90DR for presenting a force feedback corresponding to the excavation reaction force is provided on the right travel lever 26DR.

[0072] The discharge pressure sensor 28 includes a discharge pressure sensor 28L and a discharge pressure sensor 28R. The discharge pressure sensor 28L detects the discharge pressure of the left main pump 14L and outputs the detected value to the controller 30. The same applies to the discharge pressure sensor 28R.

[0073] The operation pressure sensor 29 includes operation pressure sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. The operation pressure sensor 29LA detects, in the form of pressure, the content of the operation in the front-rear direction on the left operation lever 26L by the operator, and outputs the detected value to the controller 30. The content of the operation is, for example, the lever operation direction, the lever operation amount (lever operation angle), and the like.

[0074] Similarly, the operation pressure sensor 29LB detects, in the form of pressure, the content of the operation in the left-right direction on the left operation lever 26L by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29RA detects, in the form of pressure, the content of the operation in the front-rear direction on the right operation lever 26R by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29RB detects, in the form of pressure, the content of the operation in the left-right direction on the right operation lever 26R by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29DL detects, in the form of pressure, the content of the operation in the front-rear direction on the left travel lever 26DL by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29DR detects, in the form of pressure, the content of the operation in the front-rear direction on the right travel lever 26DR by the operator, and outputs the detected value to the controller 30.

[0075] The controller 30 receives the output of the operation pressure sensor 29, outputs a control command to the regulator 13 as necessary, and changes the discharge amount of the main pump 14. Further, the controller 30 receives the output of the control pressure sensor 19 provided upstream of the throttle 18, outputs a control command to the regulator 13 as necessary, and changes the discharge amount of the main pump 14. The throttle 18 includes a left throttle 18L and a right throttle 18R, and the control pressure sensor 19 includes a left control pressure sensor 19L and a right control pressure sensor 19R.

[0076] In the left center bypass pipeline 40L, a left throttle valve 18L is arranged between the most downstream control valve 176L and the hydraulic oil tank. Therefore, the flow of the hydraulic oil discharged by the left main pump 14L is restricted by the left throttle valve 18L. And the left throttle valve 18L generates a control pressure for controlling the left regulator 13L. The left control pressure sensor 19L is a sensor for detecting this control pressure and outputs the detected value to the controller 30. The controller 30 controls the discharge amount of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L according to this control pressure. The controller 30 decreases the discharge amount of the left main pump 14L as this control pressure increases, and increases the discharge amount of the left main pump 14L as this control pressure decreases. The discharge amount of the right main pump 14R is controlled in the same way.

[0077] Specifically, as shown in FIG. 2, in the standby state where none of the hydraulic actuators in the excavator 100 are operated, the hydraulic oil discharged by the left main pump 14L reaches the left throttle valve 18L through the left center bypass pipeline 40L. And the flow of the hydraulic oil discharged by the left main pump 14L increases the control pressure generated upstream of the left throttle valve 18L. As a result, the controller 30 decreases the discharge amount of the left main pump 14L to the allowable minimum discharge amount and suppresses the pressure loss (pumping loss) when the discharged hydraulic oil passes through the left center bypass pipeline 40L.

[0078] On the other hand, when any of the hydraulic actuators are operated, the hydraulic oil discharged by the left main pump 14L flows into the operated hydraulic actuator through the control valve corresponding to the operated hydraulic actuator. And the flow of the hydraulic oil discharged by the left main pump 14L decreases or disappears the amount reaching the left throttle valve 18L and decreases the control pressure generated upstream of the left throttle valve 18L. As a result, the controller 30 increases the discharge amount of the left main pump 14L, circulates sufficient hydraulic oil to the operated hydraulic actuator, and ensures the driving of the operated hydraulic actuator. Note that the controller 30 controls the discharge amount of the right main pump 14R in the same way.

[0079] With the above configuration, in the standby state, the hydraulic system of FIG. 2 can suppress the wasteful energy consumption in the main pump 14. The wasteful energy consumption includes the pumping loss generated by the hydraulic oil discharged from the main pump 14 in the center bypass pipeline 40. Further, when operating the hydraulic actuator, the hydraulic system of FIG. 2 can surely supply the necessary and sufficient hydraulic oil from the main pump 14 to the hydraulic actuator to be operated.

[0080] Next, with reference to FIGS. 3A to 3D, the configuration for the controller 30 to automatically operate the actuator by the machine control function will be described. FIGS. 3A to 3D are diagrams showing a part of the hydraulic system extracted. Specifically, FIG. 3A is a diagram showing the hydraulic system part related to the operation of the arm cylinder 8, and FIG. 3B is a diagram showing the hydraulic system part related to the operation of the swing hydraulic motor 2A. Further, FIG. 3C is a diagram showing the hydraulic system part related to the operation of the boom cylinder 7, and FIG. 3D is a diagram showing the hydraulic system part related to the operation of the bucket cylinder 9.

[0081] As shown in FIGS. 3A to 3D, the hydraulic system includes a proportional valve 31 and a shuttle valve 32. The proportional valve 31 includes proportional valves 31AL to 31DL and 31AR to 31DR, and the shuttle valve 32 includes shuttle valves 32AL to 32DL and 32AR to 32DR.

[0082] The proportional valve 31 functions as a control valve for machine control. The proportional valve 31 is arranged in the pipeline connecting the pilot pump 15 and the shuttle valve 32, and is configured to be able to change the flow passage area of the pipeline. In the present embodiment, the proportional valve 31 operates according to the control command output by the controller 30. Therefore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via the proportional valve 31 and the shuttle valve 32, regardless of the operation of the operation device 26 by the operator.

[0083] The shuttle valve 32 has two inlet ports and one outlet port. One of the two inlet ports is connected to the operating device 26, and the other is connected to the proportional valve 31. The outlet port is connected to the pilot port of the corresponding control valve in the control valve 17. Therefore, the shuttle valve 32 can act on the pilot port of the corresponding control valve with the higher one of the pilot pressure generated by the operating device 26 and the pilot pressure generated by the proportional valve 31.

[0084] With this configuration, the controller 30 can operate the hydraulic actuator corresponding to the specific operating device 26 even when an operation on the specific operating device 26 is not being performed.

[0085] For example, as shown in FIG. 3A, the left operation lever 26L is used to operate the arm 5. Specifically, the left operation lever 26L utilizes the hydraulic oil discharged by the pilot pump 15 and acts on the pilot port of the control valve 176 with a pilot pressure corresponding to the operation in the front-rear direction. More specifically, when the left operation lever 26L is operated in the arm closing direction (rearward), it acts on the right pilot port of the control valve 176L and the left pilot port of the control valve 176R with a pilot pressure corresponding to the operation amount. Also, when the left operation lever 26L is operated in the arm opening direction (forward), it acts on the left pilot port of the control valve 176L and the right pilot port of the control valve 176R with a pilot pressure corresponding to the operation amount.

[0086] A switch NS is provided on the left operation lever 26L. In the present embodiment, the switch NS is a push-button switch. The operator can operate the left operation lever 26L while pressing the switch NS. The switch NS may be provided on the right operation lever 26R or at other positions within the cabin 10.

[0087] The operation pressure sensor 29LA detects the content of the front-rear direction operation on the left operation lever 26L by the operator in the form of pressure and outputs the detected value to the controller 30.

[0088] The proportional valve 31AL operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure generated by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL and the shuttle valve 32AL. The proportional valve 31AR operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure generated by the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR and the shuttle valve 32AR. The proportional valves 31AL and 31AR can adjust the pilot pressure so that the control valves 176L and 176R can be stopped at any valve position.

[0089] With this configuration, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL and the shuttle valve 32AL, regardless of the arm closing operation by the operator. That is, the arm 5 can be automatically closed. Also, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR and the shuttle valve 32AR, regardless of the arm opening operation by the operator. That is, the arm 5 can be automatically opened.

[0090] Also, as shown in FIG. 3B, the left operation lever 26L is also used to operate the slewing mechanism 2. Specifically, the left operation lever 26L utilizes the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the left-right direction operation to the pilot port of the control valve 173. More specifically, when the left operation lever 26L is operated in the left slewing direction (left direction), it applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 173. Also, when the left operation lever 26L is operated in the right slewing direction (right direction), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 173.

[0091] The operation pressure sensor 29LB detects the content of the left - right operation on the left operation lever 26L by the operator in the form of pressure, and outputs the detected value to the controller 30.

[0092] The proportional valve 31BL operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the left - hand pilot port of the control valve 173 via the proportional valve 31BL and the shuttle valve 32BL. The proportional valve 31BR operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the right - hand pilot port of the control valve 173 via the proportional valve 31BR and the shuttle valve 32BR. The proportional valves 31BL and 31BR can adjust the pilot pressure so that the control valve 173 can be stopped at an arbitrary valve position.

[0093] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left - hand pilot port of the control valve 173 via the proportional valve 31BL and the shuttle valve 32BL, regardless of the left - hand turning operation by the operator. That is, the turning mechanism 2 can be automatically turned to the left. Also, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right - hand pilot port of the control valve 173 via the proportional valve 31BR and the shuttle valve 32BR, regardless of the right - hand turning operation by the operator. That is, the turning mechanism 2 can be automatically turned to the right.

[0094] Also, as shown in FIG. 3C, the right operation lever 26R is used to operate the boom 4. Specifically, the right operation lever 26R utilizes the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the operation in the front-rear direction to the pilot port of the control valve 175. More specifically, when the right operation lever 26R is operated in the boom raising direction (rear direction), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. Also, when the right operation lever 26R is operated in the boom lowering direction (front direction), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 175R.

[0095] The operation pressure sensor 29RA detects the content of the front-rear direction operation on the right operation lever 26R by the operator in the form of pressure and outputs the detected value to the controller 30.

[0096] The proportional valve 31CL operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 through the proportional valve 31CL and the shuttle valve 32CL to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. The proportional valve 31CR operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 through the proportional valve 31CR and the shuttle valve 32CR to the left pilot port of the control valve 175L and the right pilot port of the control valve 175R. The proportional valves 31CL and 31CR can adjust the pilot pressure so that the control valves 175L and 175R can be stopped at an arbitrary valve position.

[0097] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31CL and the shuttle valve 32CL, regardless of the boom raising operation by the operator. That is, the boom 4 can be automatically raised. Also, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31CR and the shuttle valve 32CR, regardless of the boom lowering operation by the operator. That is, the boom 4 can be automatically lowered.

[0098] Also, as shown in FIG. 3D, the right operation lever 26R is also used to operate the bucket 6. Specifically, the right operation lever 26R uses the hydraulic oil discharged from the pilot pump 15 and applies a pilot pressure corresponding to the left-right direction operation to the pilot port of the control valve 174. More specifically, when the right operation lever 26R is operated in the bucket closing direction (left direction), it applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 174. Also, when the right operation lever 26R is operated in the bucket opening direction (right direction), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 174.

[0099] The operation pressure sensor 29RB detects the content of the left-right direction operation on the right operation lever 26R by the operator in the form of pressure and outputs the detected value to the controller 30.

[0100] The proportional valve 31DL operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure generated by the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31DL and the shuttle valve 32DL. The proportional valve 31DR operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure generated by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31DR and the shuttle valve 32DR. The proportional valves 31DL and 31DR can adjust the pilot pressure so that the control valve 174 can be stopped at an arbitrary valve position.

[0101] With this configuration, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31DL and the shuttle valve 32DL, regardless of the bucket closing operation by the operator. That is, the bucket 6 can be automatically closed. Also, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31DR and the shuttle valve 32DR, regardless of the bucket opening operation by the operator. That is, the bucket 6 can be automatically opened.

[0102] The excavator 100 may be configured to automatically move the lower traveling body 1 forward and backward. In this case, the hydraulic system part related to the operation of the left traveling hydraulic motor 2ML and the hydraulic system part related to the operation of the right traveling hydraulic motor 2MR may be configured in the same way as the hydraulic system part related to the operation of the boom cylinder 7 and the like.

[0103] Also, in FIGS. 2 and 3A to 3D, a hydraulic pilot circuit-equipped hydraulic operation lever is described, but an electric operation lever equipped with an electric pilot circuit may be adopted instead of the hydraulic operation lever. In this case, the lever operation amount of the electric operation lever is input to the controller 30 as an electric signal. Also, a solenoid valve is arranged between the pilot pump 15 and the pilot ports of each control valve.

[0104] The solenoid valve is configured to operate in response to an electrical signal from the controller 30. With this configuration, when a manual operation using an electric operation lever is performed, the controller 30 can control the solenoid valve with an electrical signal corresponding to the lever operation amount to increase or decrease the pilot pressure, thereby moving each control valve. Each control valve may be composed of an electromagnetic spool valve. In this case, the electromagnetic spool valve operates in response to an electrical signal from the controller 30 corresponding to the lever operation amount of the electric operation lever. Details of the electric operation lever will be described later.

[0105] Next, referring to FIG. 4, the functions of the controller 30 will be described. FIG. 4 is a functional block diagram of the controller 30. In the example of FIG. 4, the controller 30 is configured to receive signals output from an attitude detection device, an operation device 26, an object detection device 70, an imaging device 80, a switch NS, etc., execute various calculations, and output control commands to a proportional valve 31, a display device D1, a sound output device D2, etc. The attitude detection device includes a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a body tilt sensor S4, and a turning angular velocity sensor S5.

[0106] The controller 30 has an attitude recording unit 30A, a trajectory calculation unit 30B, an autonomous control unit 30C, an excavation reaction force calculation unit 30D, a condition determination unit 30E, and an output unit 30F as functional elements. Each functional element may be composed of hardware or software.

[0107] The posture recording unit 30A is configured to record information regarding the posture of the excavator 100. In the present embodiment, the posture recording unit 30A records information regarding the posture of the excavator 100 when the switch NS is pressed in the RAM. Specifically, the posture recording unit 30A records the output of the posture detection device each time the switch NS is pressed. The posture recording unit 30A may be configured to start recording when the switch NS is pressed at a first time point and end the recording when the switch NS is pressed at a second time point. In this case, the posture recording unit 30A may repeatedly record information regarding the posture of the excavator 100 at a predetermined control cycle from the first time point to the second time point.

[0108] The trajectory calculation unit 30B is configured to calculate a target trajectory, which is a trajectory drawn by a predetermined part of the excavator 100 when the excavator 100 operates autonomously. The predetermined part is, for example, a predetermined point on the back surface of the bucket 6. In the present embodiment, the trajectory calculation unit 30B calculates a target trajectory to be used when the autonomous control unit 30C operates the excavator 100 autonomously. Specifically, the trajectory calculation unit 30B calculates the target trajectory based on the information regarding the posture of the excavator 100 recorded by the posture recording unit 30A.

[0109] The trajectory calculation unit 30B may calculate the target trajectory based on the output of the LIDAR as an example of the object detection device 70, which is an example of the surrounding monitoring device. Alternatively, the trajectory calculation unit 30B may calculate the target trajectory based on the output of the imaging device 80, which is another example of the surrounding monitoring device. Alternatively, the trajectory calculation unit 30B may calculate the target trajectory based on the information regarding the posture of the excavator 100 recorded by the posture recording unit 30A and the output of the surrounding monitoring device.

[0110] The autonomous control unit 30C is configured to autonomously operate the excavator 100. In this embodiment, when a predetermined start condition is satisfied, it is configured to move a predetermined part of the excavator 100 along the target trajectory calculated by the trajectory calculation unit 30B. Specifically, when the operating device 26 is operated while the switch NS is pressed, the excavator 100 is autonomously operated so that a predetermined part of the excavator 100 moves along the target trajectory.

[0111] For example, when the left operation lever 26L is operated in the right turning direction and the right operation lever 26R is operated in the boom raising direction while the switch NS is pressed, the excavator 100 may be autonomously operated so that the lower end of the bucket 6 moves along the target trajectory. In this case, each of the left operation lever 26L and the right operation lever 26R may be operated with an arbitrary lever operation amount. Therefore, the operator can move the lower end of the bucket 6 along the target trajectory at a predetermined moving speed without worrying about the lever operation amount. Alternatively, the moving speed of the bucket 6 may be configured to change according to a change in the operation amount of the left operation lever 26L or the right operation lever 26R.

[0112] The autonomous control unit 30C may be configured to control at least one of the boom cylinder 7 and the swing hydraulic motor 2A so that the lower end of the bucket 6 follows the target trajectory. For example, the autonomous control unit 30C may semi - automatically control the swing speed of the upper swing body 3 according to the raising speed of the boom 4. For example, the higher the raising speed of the boom 4, the higher the swing speed of the upper swing body 3 may be. In this case, the boom 4 rises at a speed corresponding to the lever operation amount in the boom raising direction of the right operation lever 26R, but the upper swing body 3 may swing at a speed different from the speed corresponding to the lever operation amount in the right turning direction of the left operation lever 26L.

[0113] Alternatively, the autonomous control unit 30C may semi-automatically control the raising speed of the boom 4 according to the turning speed of the upper slewing body 3. For example, the higher the turning speed of the upper slewing body 3, the higher the raising speed of the boom 4 may be. In this case, the upper slewing body 3 turns at a speed corresponding to the lever operation amount in the right turning direction of the left operation lever 26L, but the boom 4 may rise at a speed different from the speed corresponding to the lever operation amount in the boom raising direction of the right operation lever 26R.

[0114] Alternatively, the autonomous control unit 30C may semi-automatically control both the turning speed of the upper slewing body 3 and the raising speed of the boom 4. In this case, the upper slewing body 3 may turn at a speed different from the speed corresponding to the lever operation amount in the right turning direction of the left operation lever 26L. Similarly, the boom 4 may rise at a speed different from the speed corresponding to the lever operation amount in the boom raising direction of the right operation lever 26R.

[0115] The excavation reaction force calculation unit 30D calculates the excavation reaction force. The excavation reaction force is the reaction force of the excavation force and is a force having the same magnitude as the excavation force and in the opposite direction to the excavation force. The excavation reaction force calculation unit 30D of the present embodiment automatically calculates the excavation reaction force based on the outputs of various sensors such as a cylinder pressure sensor and the posture of the excavator 100. Further, the excavation reaction force calculation unit 30D may calculate at least one of the horizontal component and the vertical component of the excavation reaction force. Further, the excavation reaction force calculation unit 30D of the present embodiment may calculate the excavation reaction force each time an excavation operation is performed.

[0116] The cylinder pressure sensor includes at least one of a boom rod pressure sensor S7R, a boom bottom pressure sensor S7B, an arm rod pressure sensor S8R, an arm bottom pressure sensor S8B, a bucket rod pressure sensor S9R, and a bucket bottom pressure sensor S9B.

[0117] The condition determination unit 30E determines whether the manner of change of the excavation reaction force calculated by the excavation reaction force calculation unit 30D satisfies a predetermined condition. The predetermined condition may be set in advance for the controller 30.

[0118] The output unit 30F outputs the result of the calculation by the controller 30. Specifically, the output unit 30F outputs the excavation reaction force calculated by the excavation reaction force calculation unit 30D to the force feedback device 90.

[0119] Further, when it is determined by the condition determination unit 30E that the way of change of the excavation reaction force satisfies a predetermined condition, the output unit 30F outputs a notification indicating that the underground state has changed. Specifically, for example, the output unit 30F may cause the display device D1 to display a message prompting the operator to check the underground state or stop the excavation operation. Further, the output unit 30F may output a warning sound or the like from the sound output device D2 or the like.

[0120] Next, with reference to FIG. 5, the operation of the excavator 100 of the present embodiment will be described. FIG. 5 is a flowchart for explaining the processing of the controller of the first embodiment.

[0121] FIG. 5 shows the processing of the controller 30 when an operator boards the excavator 100 and the operator performs an operation for manually performing an excavation operation without using the machine control function.

[0122] The controller 30 of the excavator 100 of the present embodiment starts an excavation operation according to the operation of the operator (step S501).

[0123] Subsequently, the controller 30 calculates the excavation reaction force in the excavation operation by the excavation reaction force calculation unit 30D (step S502). Subsequently, the controller 30 outputs the calculated excavation reaction force to the force feedback device 90 by the output unit 30F, and the force feedback device 90 presents a force sensation corresponding to the excavation reaction force to the operator (step S503).

[0124] Subsequently, the controller 30 determines whether or not the way of change of the excavation reaction force satisfies a predetermined condition by the condition determination unit 30E (step S504).

[0125] Specifically, the condition determination unit 30E may compare the excavation reaction force calculated in the immediately preceding excavation operation with the excavation reaction force calculated in step S502, and determine whether the way the excavation reaction force changes satisfies a predetermined condition. Further, the condition determination unit 30E may determine whether the way the excavation reaction force changes satisfies a predetermined condition based on the magnitude relationship between the excavation reaction force calculated over a certain period retroactively from the time when the excavation operation was started in step S501 and the excavation reaction force calculated in step S502.

[0126] In step S504, if the way the excavation reaction force changes does not satisfy a predetermined condition, the controller 30 ends the process.

[0127] In step S504, if it is determined that the way the excavation reaction force changes satisfies a predetermined condition, the controller 30 outputs a notification by the output unit 30F (step S505) and ends the process.

[0128] Specifically, the output unit 30F may cause the display device D1 to display a message prompting the suspension of the excavation operation, a message prompting the confirmation of the underground condition, or the like.

[0129] In this embodiment, by outputting a message prompting the stop of the excavation operation, it is possible to suppress the continuation of the excavation operation in a state where the excavation reaction force is high. In other words, it is possible to suppress the continuation of the work in a state where the load on the excavator 100 is high. Therefore, in this embodiment, the work is performed in a state where the load on the excavator 100 is appropriate, and the work efficiency can be improved.

[0130] Further, in this embodiment, by displaying a message prompting the confirmation of the underground condition, the underground condition can be confirmed by the operator. Therefore, according to this embodiment, it is possible to assist the operator in grasping the underground condition. Also, in this embodiment, when there is an unexpected buried object or the like in the ground to be excavated, it is possible to assist the operator in detecting the buried object.

[0131] Here, the usage scenario of the present embodiment will be described. The present embodiment may be used, for example, when conducting a trial excavation. A trial excavation is carried out before construction to actually dig and confirm the position and depth in order not to damage underground buried objects.

[0132] In a trial excavation, instead of digging vertically and deeply all at once, the process of digging horizontally and shallowly is repeated, and it is gradually dug deeper. Also, in conventional trial excavations, in order to avoid damage to buried objects, there are cases where excavation with a shovel 100 and manual digging are repeated, which is time-consuming.

[0133] By applying the present embodiment to a trial excavation, an operator performing the trial excavation only needs to perform manual digging, for example, when a message prompting confirmation of the underground condition is notified. Therefore, when a trial excavation is performed using the present embodiment, it is not necessary to simply repeat the trial excavation and manual digging, and the labor can be reduced.

[0134] In other words, according to the present embodiment, in a trial excavation, it is possible to suggest to the operator the possibility of the existence of buried objects, and the labor of the trial excavation can be reduced.

[0135] In the example of FIG. 5, the case where an operator performs an operation for manually performing a digging operation without using the machine control function has been described, but the present embodiment can also be applied to a digging operation using the machine control function.

[0136] In the present embodiment, when the switch NS is pressed, the machine control function is enabled. Therefore, in the state where the machine control function is enabled, when the change in the digging reaction force satisfies a predetermined condition in the process of FIG. 5, the output unit 30F may display a message or the like instructing interruption of the pressing of the switch NS on the display device D1. In other words, the output unit 30F may display a message prompting the operator to stop the digging operation.

[0137] In this way, in the present embodiment, it is possible to assist the operator in grasping the underground condition.

[0138] (Second Embodiment) The second embodiment will be described below with reference to the drawings. The second embodiment differs from the first embodiment in that the functions of the first embodiment are provided in the remote operation room of the excavator 100. Therefore, in the following description, for the functional configurations of the first embodiment and the sway, the same reference numerals as those used in the description of the first embodiment are given, and the description thereof is omitted.

[0139] FIG. 6 is a diagram showing an example of the system configuration of the remote operation system of the excavator. The remote operation system SYS of the excavator in the present embodiment includes the excavator 100, the support device 200, the management device 300, and the remote operation room RC. The remote operation system SYS is configured to support construction by one or a plurality of excavators 100.

[0140] The excavator 100 in the present embodiment acquires operation information indicating the operating state of the excavator 100. The operation information in the present embodiment may include sensor values output from an acceleration sensor and a gyro sensor provided in the attachment, sensor values output from a cylinder pressure sensor, pilot pressure, and the like.

[0141] In the remote operation system SYS, the operation information acquired by the excavator 100 may be transmitted to the management device 300 and the remote operation room RC. Note that the operation information may be transmitted to both the management device 300 and the remote operation room RC, or may be transmitted to the remote operation room RC via the management device 300.

[0142] Each of the excavator 100, the support device 200, and the management device 300 constituting the remote operation system SYS may be one or a plurality. Further, the remote operation system SYS only needs to include the excavator 100 and the remote operation room RC, and the management device 300 and the support device 200 may not be included.

[0143] The support device 200 is typically a portable terminal device, for example, a laptop computer terminal, a tablet terminal, or a smartphone, etc., carried by an operator at a construction site. The support device 200 may be a portable terminal carried by the operator of the excavator 100. The support device 200 may also be a fixed terminal device.

[0144] The management device 300 is typically a fixed terminal device, for example, a server computer (so-called cloud server) installed in a management center outside the construction site. Also, the management device 300 may be, for example, an edge server set at the construction site. Further, the management device 300 may be a portable terminal device (for example, a portable terminal such as a laptop computer terminal, a tablet terminal, or a smartphone).

[0145] Note that at least one of the support device 200 and the management device 300 may be provided with a monitor and an operating device for remote operation. In this case, the operator using the support device 200 or the administrator using the management device 300 may operate the excavator 100 while using the operating device for remote operation. The operating device for remote operation is communicably connected to the controller 30 mounted on the excavator 100 through a wireless communication network such as a short-range wireless communication network, a mobile phone communication network, or a satellite communication network.

[0146] The remote operation room RC is an example of an external device that supports remote operation of the excavator 100. In the app remote operation room RC, a remote controller 30R, a sound output device A2, an indoor imaging device C2, a display device RD, a communication device T2, etc. are installed. Also, in the remote operation room RC, a driver's seat DE on which an operator OP who remotely operates the excavator 100 sits is installed.

[0147] The remote controller 30R is an arithmetic device that executes various calculations. In the present embodiment, the remote controller 30R is configured by a microcomputer including a CPU and a memory, similar to the controller 30. And various functions of the remote controller 30R are realized by the CPU executing a program stored in the memory.

[0148] Further, the remote controller 30R of the present embodiment may have the same functions as those of the controller 30 of the excavator 100 of the first embodiment. In that case, the controller 30 may not have the excavation reaction force calculation unit 30D, the condition determination unit 30E, and the output unit 30F.

[0149] The sound output device A2 is configured to output sound. In the present embodiment, the sound output device A2 is a speaker, and may reproduce the sound collected by a sound collection device (not shown) attached to the excavator 100.

[0150] The indoor imaging device C2 is configured to image the inside of the remote operation room RC. In the present embodiment, the indoor imaging device C2 is a camera installed inside the remote operation room RC, and is configured to image the operator OP sitting on the driver's seat DE.

[0151] The communication device T2 controls wireless communication with the communication device T1 attached to the excavator 100. In the present embodiment, the communication device T1 mounted on the excavator 100 and the communication device T2 may transmit and receive information via a fifth-generation mobile communication line (5G line), an LTE line, a satellite line, or the like.

[0152] The driver's seat DE has the same structure as the driver's seat installed in the cabin 10 of a normal excavator. In front of the driver's seat DE, a travel lever and travel pedals are arranged. Further, a dial 75 is arranged at the center of the upper surface of the right console box. Each of the left operation lever, the right operation lever, the travel lever, and the travel pedals constitutes the operation device 26E.

[0153] Furthermore, the operation device 26E is provided with a force feedback device 90E for feeding back a sense of force corresponding to the excavation reaction force calculated by the excavation reaction force calculation unit 30D to the operator OP via the operation device 26E. Note that the force feedback device 90E may include a shaking device that shakes the driver's seat DE according to the excavation reaction force.

[0154] Dial 75 is a dial for adjusting the engine speed of engine 11 and is configured to be able to switch the engine speed in four steps, for example.

[0155] Specifically, dial 75 is configured to be able to switch the engine speed in four steps: SP mode, H mode, A mode, and idling mode. Dial 75 transmits data regarding the setting of the engine speed to controller 30.

[0156] SP mode is a speed mode selected when operator OP wants to prioritize the amount of work and uses the highest engine speed. H mode is a speed mode selected when operator OP wants to balance the amount of work and fuel consumption and uses the second highest engine speed. A mode is a speed mode selected when operator OP wants to operate the shovel with low noise while prioritizing fuel consumption and uses the third highest engine speed. The idling mode is a speed mode selected when operator OP wants to put the engine in an idling state and uses the lowest engine speed. Then, engine 11 is constantly speed-controlled at the engine speed of the speed mode selected via dial 75.

[0157] The operating device 26E is provided with an operating pressure sensor 29A for detecting the operation content of the operating device 26E. The operating pressure sensor 29A is, for example, an inclination sensor for detecting the inclination angle of the operating lever, or an angle sensor for detecting the swing angle around the swing axis of the operating lever. The operating pressure sensor 129A may be composed of other sensors such as a pressure sensor, a current sensor, a voltage sensor, or a distance sensor. The operating pressure sensor 29A outputs information regarding the detected operation content of the operating device 26E to the remote controller 30R. The remote controller 30R generates an operation signal based on the received information and transmits the generated operation signal toward the excavator 100. The operating pressure sensor 29A may be configured to generate an operation signal. In this case, the operating pressure sensor 29A may output the operation signal to the communication device T2 without passing through the remote controller 30R.

[0158] The display device RD is configured to display information regarding the situation around the excavator 100. In the present embodiment, the display device RD is a multi-display composed of nine monitors arranged in three rows and three columns vertically, and is configured to be able to display the states of the spaces in front of, to the left of, and to the right of the excavator 100. Each monitor is a liquid crystal monitor or an organic EL monitor, etc. However, the display device RD may be composed of one or a plurality of curved monitors, or may be composed of a projector. Also, the display device RD may be configured to be able to display the states of the spaces in front of, to the left of, to the right of, and behind the excavator 100.

[0159] Also, a message output from the output unit 30F of the remote controller 30R may be displayed on the display device RD.

[0160] Further, the display device RD may be a display device wearable by the operator OP. For example, the display device RD may be a head-mounted display and may be configured to transmit and receive information to and from the remote controller 30R by wireless communication. The head-mounted display may be wired-connected to the remote controller 30R. The head-mounted display may be a transmissive head-mounted display or a non-transmissive head-mounted display. The head-mounted display may be a single-eye type head-mounted display or a binocular type head-mounted display.

[0161] Further, the display device RD is configured to display an image that allows the operator OP in the remote operation room RC to visually recognize the surroundings of the excavator 100. That is, the display device RD displays an image so that the operator can confirm the situation around the excavator 100 as if the operator were inside the cab 10 of the excavator 100 even though the operator is in the remote operation room RC.

[0162] Next, with reference to FIG. 7, the processing of the remote controller 30R in the remote operation room RC of the present embodiment will be described. FIG. 7 is a flowchart for explaining the processing of the remote controller according to the second embodiment.

[0163] The remote controller 30R of the present embodiment starts an excavation operation on the excavator 100 in response to an operation by the operator OP (step S701). Subsequently, the remote controller 30R acquires operation information from the excavator 100 (step S702).

[0164] Subsequently, the remote controller 30R calculates the excavation reaction force of the excavator 100 based on the acquired operation information by the excavation reaction force calculation unit 30D (step S703) and proceeds to step S704.

[0165] The processing from step S704 to step S706 in FIG. 7 is the same as the processing of steps S503 and S506 in FIG. 5, except that the output destination of the notification in step S706 is the display device RD, and thus the description thereof will be omitted.

[0166] As described above, in this embodiment, even in the remote operation cab RC for remotely operating the excavator 100, the excavation reaction force of the excavator 100 can be used to assist the operator OP in grasping the underground state.

[0167] Also, in this embodiment, the excavation reaction force is fed back to the operator OP via the operating device 26E and the driver's seat DE included in the remote operation cab RC. The excavation reaction force is fed back to the operator OP.

[0168] Therefore, in this embodiment, not only the change in the underground state but also the feeling when the body of the excavator 100 floats and the feeling when the body of the excavator 100 is dragged are fed back to the operator OP.

[0169] Therefore, in this embodiment, it is possible to make the operator OP experience a feeling similar to that of being on board the excavator 100 at the work site, and it is possible to assist the operator OP in grasping the load on the excavator 100 during operation.

[0170] Note that in the example of FIG. 7, the output destination of the notification by the output unit 30F is the display device RD, but it is not limited thereto. The notification by the output unit 30F may be output to, for example, the support device 200.

[0171] More specifically, in this embodiment, when the condition determination unit 30E determines that the excavation reaction force satisfies a predetermined condition, the output unit 30F may cause the display device RD to display a message instructing to stop the excavation operation and cause the display device of the support device 200 to display a message instructing to confirm the underground state.

[0172] By doing so, for example, when conducting a trial excavation using the remote operation system SYS, the operator OP in the remote operation room RC and the worker assisting with the work at the work site can cooperate to check the underground conditions. Therefore, according to the present embodiment, the detection of buried objects can be assisted.

[0173] Also, in the above-described embodiment, a hydraulic operation device is adopted as the operation device 26, but an electric operation device may be adopted. FIG. 8 is a diagram showing a configuration example of an operation system including an electric operation device. Specifically, the operation system in FIG. 8 is an example of a boom operation system and mainly includes a pilot pressure-operated control valve 17, a right operation lever 26R as an electric operation lever, a controller 30, a solenoid valve 60 for boom raising operation, and a solenoid valve 62 for boom lowering operation. The operation system in FIG. 8 can be similarly applied to an arm operation system, a bucket operation system, etc.

[0174] The pilot pressure-operated control valve 17 includes control valves 175L and 175R for the boom cylinder 7. The solenoid valve 60 is configured to be able to adjust the flow passage area of the oil passage connecting the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R, respectively. The solenoid valve 62 is configured to be able to adjust the flow passage area of the oil passage connecting the pilot pump 15 to the right pilot port of the control valve 175R.

[0175] When manual operation is performed, the controller 30 generates a boom raising operation signal (electrical signal) or a boom lowering operation signal (electrical signal) according to the operation signal (electrical signal) output by the operation signal generation unit of the right operation lever 26R. The operation signal output by the operation signal generation unit of the right operation lever 26R is an electrical signal that changes according to the operation amount and operation direction of the right operation lever 26R.

[0176] Specifically, when the right operation lever 26R is operated in the boom raising direction, the controller 30 outputs a boom raising operation signal (electrical signal) corresponding to the lever operation amount to the solenoid valve 60. The solenoid valve 60 adjusts the flow passage area according to the boom raising operation signal (electrical signal) and controls the pilot pressure acting on the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. Similarly, when the right operation lever 26R is operated in the boom lowering direction, the controller 30 outputs a boom lowering operation signal (electrical signal) corresponding to the lever operation amount to the solenoid valve 62. The solenoid valve 62 adjusts the flow passage area according to the boom lowering operation signal (electrical signal) and controls the pilot pressure acting on the right pilot port of the control valve 175R.

[0177] When executing automatic control, instead of the operation signal output by the operation signal generation unit of the right operation lever 26R, the controller 30 generates a boom raising operation signal (electrical signal) or a boom lowering operation signal (electrical signal) according to a correction operation signal (electrical signal). The correction operation signal may be an electrical signal generated by the controller 30 or an electrical signal generated by a control device other than the controller 30.

[0178] In the above-described embodiment, the hydraulic excavator 100 is taken as an example of a working machine, and the excavation reaction force in the excavation operation is used, but the present invention is not limited thereto. The working machine of the present embodiment can be applied to any working machine as long as the working object is the ground and the working machine receives a working reaction force. For example, in the present embodiment, instead of the excavation reaction force, it may be applied to a working machine that receives a reaction force when pressing the ground to compact the ground.

[0179] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments. Various modifications, substitutions, etc. can be applied to the above-described embodiments without departing from the scope of the present invention. Also, the features described separately can be combined as long as there is no technical contradiction.

Explanation of Reference Numerals

[0180] 1 Lower traveling body 2 Slewing mechanism 3 Upper slewing body 4 Boom 5 Arm 6 Bucket 30 Controller 100 Excavator

Claims

1. A lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, an attachment attached to the upper slewing body, a sensor attached to the upper slewing body, a control device that calculates, each time the excavation operation is performed, the excavation reaction force generated by the excavation operation based on the output of the sensor, and outputs a notification indicating that the underground state around the ground where the excavation is being performed by the excavation operation is different from the underground state of other grounds when the manner of change of the excavation reaction force satisfies a predetermined condition. A working machine having the above components.

2. The predetermined condition is that the excavation reaction force changes by a certain width or more within a predetermined time. The working machine according to claim 1.

3. The predetermined condition is that the excavation reaction force increases exponentially. The working machine according to claim 1.

4. The control device causes a display device to display, as the notification, a message instructing to stop the excavation operation. The working machine according to claim 1.

5. The control device causes a display device to display, as the notification, a message prompting to check the underground state. The working machine according to claim 1.

6. The underground state around the ground where the excavation is being performed by the excavation operation being different from the state of other grounds includes a state where there are buried objects in the ground around the ground where the excavation is being performed by the excavation operation, a state where there are cavities in the ground around the ground where the excavation is being performed by the excavation operation, and a state where there are softer objects than the ground in the ground around the ground where the excavation is being performed by the excavation operation. The working machine according to claim 1.

7. The other ground includes a ground where an excavation operation has already been performed. The working machine according to claim 1.

8. A remote operation system for a working machine having a lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, an attachment attached to the upper slewing body, and a sensor attached to the upper slewing body, and an external device that supports remote operation of the working machine, wherein the external device has a control device that calculates, each time the excavation operation is performed, the excavation reaction force generated by the excavation operation based on the output of the sensor, and outputs a notification indicating that the underground state around the ground where the excavation is being performed by the excavation operation is different from the underground state of other grounds when the manner of change of the excavation reaction force satisfies a predetermined condition. A remote operation system for a working machine.

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