WORKING MACHINE AND REMOTE CONTROL SYSTEM FOR WORKING MACHINE

Abstract

A work machine includes a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, a sensor attached to the upper rotating body, and a control device configured to calculate an excavation reaction force generated by an excavation operation each time the excavation operation is performed based on the output of the sensor, and output a message indicating that a condition of the soil adjacent to the soil excavated by the excavation operation is different from the condition of the other soil when change in the excavation reaction force satisfies a predetermined condition.

Description

BACKGROUNDTechnical FieldThe present disclosure relates to work machines and remote control systems for work machines.Description of Related ArtIn the related art, an excavator is known in which a working part such as an arm including an actuator feeds back a working reaction force received from an object to be worked or the like to an operator via an operation part that sends a command to the working part.SUMMARY OF THE INVENTIONPROBLEM TO BE SOLVED BY THE INVENTIONIn the related art, for example, an excavation reaction force in an excavation operation may be fed back to the operator. However, according to the related art, it is difficult for the operator to understand the existence of a hidden object and the possibility of damage to the hidden object by the excavation operation when, for example, a hidden object is present under an excavation surface. That is, according to the related art, it is difficult to cause the operator to understand a state of the floor.In the present disclosure, it is desirable to assist in understanding the state of the floor.MEANS FOR SOLVING THE PROBLEMA work machine includes a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, a sensor mounted on the upper rotating body, and a control device configured to calculate an excavation reaction force generated by an excavation operation each time the excavation operation is performed based on the output of the sensor, and output a message indicating that a state of the ground adjacent to the ground excavated by the excavation operation is different from the state of the other ground when change in the excavation reaction force satisfies a predetermined condition.A remote control system for a work machine includes the work machine having a lower traveling body, an upper swinging body rotatably mounted on the lower traveling body, a appendix attached to the upper swinging body, and a sensor attached to the upper swinging body, and an external device configured to assist remote control of the work machine, wherein the external device includes a control device for calculating an excavation reaction force generated by an excavation operation each time the excavation operation is performed, based on the output of the sensor, and outputting a notification indicating that a state of soil adjacent to the soil excavated by the excavation operation is different from the state of the other soil when change of the excavation reaction force satisfies a predetermined condition.EFFECT OF THE INVENTIONAn object of the present disclosure is to assist in understanding the state of the floor.BRIEF DESCRIPTION OF THE DRAWINGS[FIG. 1A] FIG. 1A is a side view of an excavator according to an embodiment of the present invention.[FIG. 1B ] FIG. 1B is a plan view of the excavator according to the embodiment of the present invention.[FIG. 2 ] FIG. 2 is a schematic diagram showing a configuration example of a hydraulic system mounted on the excavator of FIG. 1A.[FIG. 3A] FIG. 3A is a cutaway drawing of the hydraulic system portion related to an operation of an arm cylinder.[FIG. 3B ] FIG. 3B is a cutaway drawing of the hydraulic system portion related to an operation of a swing hydraulic motor.[FIG. 3C ] FIG. 3C is a cross-sectional view of the hydraulic system portion related to an operation of a boom cylinder.[FIG. 3D ] FIG. 3D is a cutaway drawing of the hydraulic system portion related to operation of a bucket cylinder.[FIG. 4] FIG. 4 is a functional block diagram of a controller.[FIG. 5 ] FIG. 5 is a flowchart showing processing of control of an embodiment.[FIG. 6 ] FIG. 6 is a drawing showing an example of the system configuration of a remote control system of the excavator.[FIG. 7 ] FIG. 7 is a flowchart showing processing of remote control of another embodiment.[FIG. 8] FIG. 8 is a drawing showing a configuration example of an operating system including an electric operation device.DETAILED DESCRIPTION(EMBODIMENT 1)First, an excavator 100 as an excavator according to an embodiment of the present invention will be described with reference to FIGS. 1A and 1B. FIG. 1A is a side view of the excavator 100, and FIG. 1B is a plan view of the excavator 100.In the present embodiment, a lower traveling body 1 of the excavator 100 includes a crawler 1C. The crawler 1C is driven by a traveling hydraulic motor 2M mounted on the lower traveling body 1. The track 1C includes, in particular, a left track 1CL and a right track 1CR. The left crawler 1CL is driven for traveling by a left traveling hydraulic motor 2ML, and the right crawler 1CR is driven for traveling by a right traveling hydraulic motor 2MR.The upper swing body 3 is rotatably mounted to the lower traveling body 1 via a swing mechanism 2. The swing mechanism 2 is driven by a swing hydraulic motor 2A mounted on the upper swing body 3. However, the swing hydraulic motor 2A may be a swing motor generator as an electric actuator.A boom 4 is attached to the upper swing body 3. An arm 5 is attached to a 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 as 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.The boom 4 is rotatably supported by the upper swing body 3. A boom angle sensor S 1 is attached to the boom 4. The boom angle sensor S 1 can detect a boom angle β 1 which is a rotation angle of the boom 4. The boom angle β 1 is, for example, a elevation angle from a state in which the boom 4 is maximally lowered. Therefore, the boom angle β 1 is maximum when the boom 4 is maximally raised.The arm 5 is rotatably supported with respect to the boom 4. An arm angle sensor S2 is attached to the arm 5. The arm angle sensor S 2 can detect the arm angle β 2 which is the rotation angle of the arm 5. The arm angle β 2 is, for example, an opening angle of the most closed state of the arm 5.The bucket 6 is rotatably supported with respect to the arm 5 by the bucket link mechanism 6 a. A blade angle sensor S 3 is attached to the blade 6. The blade angle sensor S 3 may detect the blade angle β 3 which is the rotation angle of the blade 6. The blade angle β 3 is the opening angle of the most closed state of the blade 6.In the embodiment shown in FIGS. 1A and 1B, the boom angle sensor S 1, the arm angle sensor S 2, and the bucket angle sensor S 3 are each configured of a combination of an acceleration sensor and a gyro sensor. However, at least one of the boom angle sensor S 1, the arm angle sensor S 2, and the bucket angle sensor S 3 may be composed of only the acceleration sensor. The boom angle sensor S 1 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 S 2 and the blade angle sensor S 3.The upper swing body 3 is provided with a cab 10 as a control cab, and a power source such as an engine 11 is mounted thereon. On the upper swing body 3, an object detection device 70, an imaging device 80, an engine body inclination sensor S 4, a swing angle speed sensor S 5, and the like are mounted. In the cabin 10, an operation device 26, a controller 30, a display device D 1, a sound output device D 2, and the like are provided. For convenience, in the present document, a direction of the upper swing body 3 to which the excavation extension AT is attached is referred to as a front direction, and a direction to which a counterweight is attached is referred to as a rear direction.The object detection device 70 is an example of an environment monitoring device, and is configured to detect an object located around the excavator 100. The object may be, for example, a person, an animal, a vehicle, construction equipment, 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 range 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 side of the cabin 10, a rear sensor 70B attached to the rear end of the upper side of the upper swing body 3, a left sensor 70L attached to the left end of the upper side of the upper swing body 3, and a right sensor 70R attached to the right end of the upper side of the upper swing body 3.The object detection device 70 may be configured to detect a predetermined object in a predetermined area around the excavator 100. The object detection device 70 may be configured to distinguish between a person and a non-human object. The object detection device 70 may be configured to calculate a distance from the object detection device 70 or the excavator 100 to a detected object.The imaging device 80 is another example of an environment monitoring device that captures images of the environment of the excavator 100. In the present embodiment, the imaging device 80 includes a rear camera 80B attached to the upper rear end of the upper rotating body 3, a left camera 80L attached to the upper left end of the upper rotating body 3, and a right camera 80R attached to the upper right end of the upper rotating body 3. The imaging device 80 may include a front camera.The rear camera 80B is disposed adjacent to the rear sensor 70B, the left camera 80L is disposed adjacent to the left sensor 70L, and the right camera 80R is disposed adjacent to the right sensor 70R. When the imaging device 80 includes a front camera, the front camera may be disposed adjacent to the front sensor 70F.The image captured by the imaging device 80 is displayed on the display device D 1. The imaging device 80 may be configured to display a view angle converted image such as a bird's eye view image on the display device D 1. The bird's-eye view image is generated by, for example, the combination of images output from the rear camera 80B, the left camera 80L, and the right camera 80R.The engine body inclination sensor S 4 is configured to detect an inclination of the upper swing body 3 with respect to a predetermined plane. In the present embodiment, the engine body inclination sensor S 4 is an acceleration sensor for detecting an inclination angle about the front-rear axis (roll angle) and the inclination angle about the left-right axis (pitch angle) of the upper swing body 3 with respect to a horizontal plane. The front-rear axis and the left-right axis of the upper swing body 3 are orthogonal to each other, for example, and pass through the excavator center point, which is a point on the swing axis of the excavator 100. The machine body inclination sensor S 4 may be configured by a combination of an acceleration sensor and a gyro sensor.The swing angular velocity sensor S 5 is configured to detect the swing angular velocity of the upper swing body 3. In the present embodiment, the swing angular velocity sensor S 5 is a gyro sensor. The swing angular velocity sensor S 5 may be a resolver, a rotary encoder, or the like. The swing angular velocity sensor S 5 may detect the swing velocity. The swing speed can be calculated from the swing angle speed.Hereinafter, the boom angle sensor S 1, the arm angle sensor S 2, the bucket angle sensor S 3, the machine body inclination sensor S 4, and the swing angle speed sensor S 5 are also referred to as a posture detection device.The display device D 1 is configured to display various information. The sound output device D 2 is configured to output sound.The operation device 26 is a device that the operator uses to operate the actuator. The operation device 26 of the present embodiment is provided with a force feedback device 90. The force feedback device 90 feeds back the excavation reaction force corresponding to the excavation reaction force calculated by the controller 30, for example, to the operator via the operation device 26.More specifically, the force feedback device 90 increases the force required for tilting the operation lever included in the operation device 26 or vibrates the operation lever according to the excavation reaction force input from the controller 30. The force feedback device 90 may also shake the operator seat provided in the cab 10 in accordance with the excavation reaction force, for example.The controller 30 is a controller for controlling the excavator 100. In the present embodiment, the controller 30 includes a computer including a CPU, a volatile memory device, a nonvolatile memory device, and the like. The controller 30 reads and executes programs corresponding to the respective functions from the nonvolatile memory device. The respective functions include, for example, a machine guidance function for guiding the manual operation of the excavator 100 by the operator, a machine control function for automatically assisting the manual operation of the excavator 100 by the operator, and the like.Further, the controller 30 of the present embodiment calculates the excavation reaction force when the excavator 100 performs an excavation operation, and outputs the result to the force feedback device 90. Further, the controller 30 of the present embodiment outputs, to the operator, a message indicating that the state of the floor near a position to be excavated is different from a state of another floor when the type of change in excavation reaction force during the excavation operation satisfies a predetermined condition. The states in which the state of the ground near the to-be-excavated position is different from the state of the other ground in the present embodiment include states that there is a hidden object in the ground near the ground excavated by the excavation operation, that there is a hollow in the ground near the ground excavated by the excavation operation, and that there is an object softer than the ground in the ground near the to-be-excavated position.In the present embodiment, the message indicating that the state of the ground is different may include, for example, a message instructing setting of excavation work or a message requesting confirmation of the ground state. The other floor may include the floor on which excavation work has already been performed.In the present embodiment, the predetermined condition may specifically include, for example, a sudden increase in an amount or a sudden decrease in an amount. In other words, the case where the variation of the excavation reaction force satisfies a predetermined condition may include a case where the excavation reaction force varies (becomes larger or smaller) by a predetermined amount or more within a predetermined period.The case where the excavation reaction force changes (increases) by a predetermined amount or more within a predetermined time may be, for example, a case where the tip of the bucket 6 comes into contact with a hidden object present in the ground where excavation is performed, a case where the tip of the bucket 6 approaches a hidden object present in the ground where excavation is performed, or the like. The case where the excavation reaction force changes (decreases) by a predetermined amount within a predetermined time may be, for example, a case where a cavity or an object softer than the ground is present in the ground where excavation is performed, a case where a hidden object present in the ground is destroyed, or the like. In the present embodiment, by setting the above-described predetermined condition, the operator can be made to estimate which kind of object the tip of the excavator 6 in the ground comes into contact with.In the present embodiment, the predetermined condition may be an exponentially increasing tendency. The case where the excavation reaction force has an exponentially increasing tendency indicates a situation where the soil with which the tip of the blade 6 comes into contact suddenly becomes hard. In the present embodiment, for example, by setting the above-described predetermined condition, the operator can be made to understand the possibility that the tip of the blade 6 approaches the hidden object.As described above, according to the present embodiment, a change in the state of the soil where excavation is performed is detected from the change in the excavation reaction force, and this fact is notified to the operator of the excavator 100. Therefore, according to the present embodiment, it is possible to cause the operator to perform the work in consideration of the state of the floor.Further, according to the present embodiment, a feeling of force corresponding to the excavation reaction force is fed back to the operator. Therefore, according to the present embodiment, it is possible to cause the operator to feel the load on the excavator 100 as a feeling of force, and it is possible to urge the operator to avoid the work with a high load. Therefore, according to the present embodiment, it is possible to reduce the load on the excavator 100, and work efficiency can be improved.Details of the operation of the controller 30 of the present embodiment will be described later.In the following description, it is assumed that the force feedback device 90 is provided in the operation device 26, but the present invention is not limited thereto. The force feedback device 90 may be mounted on the hand or the like of an operator who operates the excavator 100. In this case, the force feedback device 90 may communicate with the controller 30 to acquire information indicating the excavation reaction force calculated by the controller 30.The excavation reaction force to the excavator 100 in the present embodiment is an example of the work reaction force to the work machine.Next, another configuration example of the hydraulic system mounted on the excavator 100 will be described with reference to FIG. 2. FIG. 2 is a drawing showing another configuration example of the hydraulic system mounted on the excavator 100. FIG. 2 shows a mechanical power transmission system, a hydraulic fluid line, a pilot line, and an electric control system by double lines, solid lines, dotted lines, and dotted lines, respectively.The hydraulic system illustrated in FIG. 2 basically 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 operation pressure sensor 29, a controller 30, and the like.In FIG. 2, the hydraulic system circulates hydraulic fluid from a main pump 14 driven by an engine 11 through a center bypass line 40 or a parallel line 42 to a hydraulic fluid tank.The motor 11 is a drive source for the excavator 100. In the present embodiment, the engine 11 is, for example, a diesel engine that operates to maintain a predetermined rotation speed. The output shaft of the engine 11 is connected to the input shaft of the main pump 14 and the pilot pump 15.The main pump 14 supplies hydraulic fluid to the control valve 17 via a hydraulic fluid line. In the present embodiment, the main pump 14 is a swash plate type hydraulic variable displacement pump.The controller 13 controls the discharge amount of the main pump 14. in the present embodiment, the controller 13 controls the discharge amount of the main pump 14 by adjusting the swash plate inclination angle of the main pump 14 according to a control command of the controller 30.The pilot pump 15 is configured to supply hydraulic fluid 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 of the pilot pump 15 may be adopted by the main pump 14. That is, the main pump 14 may also have a function of supplying the hydraulic fluid to the operating device 26 or the like after the pressure of the hydraulic fluid is reduced by a throttle or the like, in addition to the function of supplying the hydraulic fluid to the control valve 17.The control valve 17 is a hydraulic control device for controlling the hydraulic system in the excavator 100. In the present embodiment, the control valve 17 includes control valves 171 to 176. Control valves 175 include a control valve 175L and a control valve 175R, and control valves 176 include a control valve 176L and a control valve 176R. The control valve 17 may selectively supply hydraulic fluid discharged from the main pump 14 to one or more hydraulic actuators via the control valves 171 to 176. The control valves 171 to 176 control the flow rate of the hydraulic fluid flowing from the main pump 14 to the hydraulic actuator and the flow rate of the hydraulic fluid flowing from the hydraulic actuator to the hydraulic fluid tank. The hydraulic actuator includes 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.The operation device 26 is a device used by an operator to operate the actuator. The actuator includes at least one of a hydraulic actuator and an electric actuator. In the present embodiment, the operating device 26 supplies the hydraulic fluid discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via a pilot line. The pressure (pilot pressure) of the hydraulic fluid supplied to each pilot port is a pressure corresponding to the operation direction and the operation amount of the operation device 26 associated with each hydraulic actuator. However, the operating device 26 may be an electrically controlled type, instead of a pilot pressure type as described above. In this case, the control valve in the control valve 17 may be an electromagnetic spool valve.A discharge pressure sensor 28 detects the discharge pressure of the main pump 14.An operation pressure sensor 29 detects the contents of the operation of the operation device 26 by the operator. In the present embodiment, the operation pressure sensor 29 detects the operation direction and the operation amount of the lever or pedal of the operation device 26 corresponding to each actuator in the form of pressure (operation pressure), and outputs the detected value to the controller 30. The contents of the operation of the operation device 26 can be detected using a sensor other than the operation pressure sensor.The main pumps 14 include a left main pump 14L and a right main pump 14R. The left main pump 14L circulates the hydraulic fluid to the hydraulic fluid tank via the left center bypass line 40L or the left parallel line 42L, and the right main pump 14R circulates the hydraulic fluid to the hydraulic fluid tank via the right center bypass line 40R or the right parallel line 42R.The left center bypass line 40L is a hydraulic fluid line passing through control valves 171, 173, 175L, and 176L disposed in the control valve 17. The right center bypass line 40R is a hydraulic fluid line passing through control valves 172, 174, 175R, and 176R disposed in the control valve 17.The control valve 171 is a spool valve for supplying the hydraulic fluid discharged from the left main pump 14L to the left traveling hydraulic motor 2ML and switching the flow of the hydraulic fluid to discharge the hydraulic fluid discharged from the left traveling hydraulic motor 2ML to the hydraulic fluid tank.The control valve 172 is a spool valve for supplying the hydraulic fluid discharged from the right main pump 14R to the right traveling hydraulic motor 2MR and switching the flow of the hydraulic fluid to discharge the hydraulic fluid discharged from the right traveling hydraulic motor 2MR to the hydraulic fluid tank.The control valve 173 is a spool valve for supplying the hydraulic fluid discharged from the left main pump 14L to the swing hydraulic motor 2A and switching the flow of the hydraulic fluid to discharge the hydraulic fluid discharged from the swing hydraulic motor 2A to the hydraulic fluid tank.The control valve 174 is a spool valve for supplying the hydraulic fluid discharged from the right main pump 14R to the bucket cylinder 9 and switching the flow of the hydraulic fluid to discharge the hydraulic fluid in the bucket cylinder 9 to the hydraulic fluid tank.The control valve 175L is a spool valve for switching the flow of the hydraulic fluid to supply the hydraulic fluid discharged from the left main pump 14L to the boom cylinder 7. The control valve 175R is a spool valve for supplying the hydraulic fluid discharged from the right main pump 14R to the boom cylinder 7 and switching the flow of the hydraulic fluid to discharge the hydraulic fluid in the boom cylinder to the hydraulic fluid tank.The control valve 176L is a spool valve for supplying the hydraulic fluid discharged from the left main pump 14L to the arm cylinder 8 and switching the flow of the hydraulic fluid to discharge the hydraulic fluid in the arm cylinder 8 to the hydraulic fluid tank.The control valve 176R is a spool valve for supplying the hydraulic fluid supplied from the right main pump 14R to the arm cylinder 8 and switching the flow of the hydraulic fluid to discharge the hydraulic fluid in the arm cylinder 8 to the hydraulic fluid tank.The left parallel line 42L is a hydraulic fluid line parallel to the left center bypass line 40L. The left parallel line 42L may supply hydraulic fluid to a control valve further downstream when the flow of hydraulic fluid through the left center bypass line 40L is restricted or blocked by one of the control valves 171, 173, and 175L. The right parallel line 42R is a hydraulic fluid line parallel to the right center bypass line 40R. Right parallel line 42R may supply hydraulic fluid to a control valve further downstream when hydraulic fluid flow through right center bypass line 40R is restricted or blocked by one of control valves 172, 174, and 175R.The controller 13 includes a left controller 13L and a right controller 13R. The left regulator 13L controls the discharge amount of the left main pump 14L by adjusting the swash plate inclination angle of the left main pump 14L according to the discharge pressure of the left main pump 14L. More specifically, the left regulator 13L decreases the discharge amount by adjusting, for example, the swash plate inclination angle of the left main pump 14L according to an increase in the discharge pressure of the left main pump 14L. The same applies to the right regulator 13R. This is so that an absorbed power of the main pump 14 resulting from the product of the discharge pressure and the discharge amount does not exceed an output of the engine 11.The operation device 26 includes a left operation lever 26L, a right operation lever 26R, and a travel lever 26D. The travel lever 26D includes a left travel lever 26DL and a right travel lever 26DR.The left operation lever 26L is used for a swinging operation and the operation of the arm 5. When the left operation lever 26L is operated in a longitudinal direction, the control pressure corresponding to the lever operation amount is introduced into the pilot port of the control valve 176 by using the hydraulic fluid discharged from the pilot pump 15. When the left operation lever 26L is operated in the lateral direction, the control pressure corresponding to the lever operation amount is introduced into the pilot port of the control valve 173 by using the hydraulic fluid discharged from the pilot pump 15.Specifically, when the left operation lever 26L is operated in the arm closing direction, the hydraulic fluid is introduced into the right pilot port of the control valve 176L and the hydraulic fluid is introduced into the left pilot port of the control valve 176R. When the left operation lever 26L is operated in the arm opening direction, the operation oil is introduced into the left pilot port of the control valve 176L, and the operation oil is introduced into the right pilot port of the control valve 176R. When the left operation lever 26L is operated in a leftward swing direction, it causes the left pilot port of the control valve 173 to introduce the hydraulic fluid, and when operated in a rightward swing direction, it causes the right pilot port of the control valve 173 to introduce the hydraulic fluid.The left operation lever 26L is provided with a force feedback device 90L for feedbacking a force feeling corresponding to the excavation reaction reaction force.The right operation lever 26R is used for operating the boom 4 and the bucket 6. When operated in the front and rear directions, the right operation lever 26R uses the hydraulic fluid discharged from the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 175. When operated in the left and right directions, the control pressure corresponding to the lever operation amount is introduced into the pilot port of the control valve 174 using the hydraulic fluid discharged from the pilot pump 15.Specifically, when operated in a boom downward direction, the right operation lever 26 introduces hydraulic fluid into the left pilot port of the control valve 175R. When operated in a boom upward direction, the right operation lever 26R causes hydraulic fluid to be introduced into the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. When operated in the blade closing direction, the right operation lever 26R causes hydraulic fluid to be introduced into the right pilot port of the control valve 174, and when operated in the blade opening direction, causes hydraulic fluid to be introduced into the left pilot port of the control valve 174.The right operation lever 26R is provided with a force feedback device 90R for feedbacking a force feeling corresponding to the excavation reaction reaction force.The travel lever 26D is used to operate the crawler 1C. Specifically, the left travel lever 26DL is used for operating the left crawler 1CL. It may be configured to be coupled to the left accelerator pedal. When the left travel lever 26DL is operated in the front-rear direction, the control pressure corresponding to the operation amount of the lever is introduced into the pilot port of the control valve 171 using the hydraulic fluid discharged from the pilot pump 15. The left travel lever 26DL is provided with a force feedback device 90DL for feedback of a force feeling corresponding to the excavation reaction reaction reaction force.The right hand lever 26DR is used to operate the right crawler 1CR. It may be configured to be coupled to the right accelerator pedal. When the right travel lever 26DR is operated in the longitudinal direction, the control pressure corresponding to the operation amount of the lever is introduced into the pilot port of the control valve 172 using the hydraulic fluid discharged from the pilot pump 15. The right travel lever 26DR is provided with a force feedback device 90DR for feedback of a force feeling corresponding to the excavation reaction reaction force.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.The operation pressure sensor 29 includes operation pressure sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. The operation pressure sensor 29LA detects the contents of the operation of the left operation lever 26L by the operator in the longitudinal direction in the form of pressure, and outputs the detected value to the controller 30. The contents of the operation are, for example, a lever operation direction, a lever operation amount (lever operation angle), and the like.Similarly, the operation pressure sensor 29LB detects the contents of the operation of the left operation lever 26L by the operator in the longitudinal direction in the form of pressure, and outputs the detected value to the controller 30. The operation pressure sensor 29RA detects the contents of the operation of the right operation lever 26R by the operator in the longitudinal direction in the form of pressure, and outputs the detected value to the controller 30. The operation pressure sensor 29RB detects the contents of the operation of the right operation lever 26R by the operator in the longitudinal direction in the form of pressure, and outputs the detected value to the controller 30. The operation pressure sensor 29DL detects the contents of the operation of the left travel lever 26DL by the operator in the longitudinal direction in the form of pressure, and outputs the detected value to the controller 30. The operation pressure sensor 29DR detects the contents of the operation of the right travel lever 26DR by the operator in the longitudinal direction in the form of pressure, and outputs the detected value to the controller 30.The controller 30 receives the output of the operation pressure sensor 29, outputs a control command to the controller 13 as needed, and changes the discharge amount of the main pump 14, the controller 30 receives the output of the control pressure sensor 19 provided upstream of the throttle 18, outputs a control command to the controller 13 as needed, 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.In the left center bypass line 40L, a left throttle 18L is disposed between the most downstream control valve 176L and the hydraulic fluid tank. Therefore, the flow rate of the hydraulic fluid discharged from the left main pump 14L is restricted by the left throttle 18L. The left throttle 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 regulator 30 controls the delivery amount of the left main pump 14L by adjusting the swash plate inclination 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 the control pressure increases, and increases the discharge amount of the left main pump 14L as the control pressure decreases. The discharge amount of the right main pump 14R is also controlled in the same manner.Specifically, when the excavator 100 is in a standby state in which none of the hydraulic actuators is operated, the hydraulic fluid discharged from the left main pump 14L flows through the left center bypass line 40L and reaches the left throttle 18L as illustrated in FIG. 2. The flow rate of the hydraulic fluid discharged from the left main pump 14L increases the control pressure generated upstream of the left throttle 18L. As a result, the controller 30 reduces the discharge amount of the left main pump 14L to an allowable minimum discharge amount and reduces pressure loss (pumping loss) when the discharged hydraulic fluid passes through the left center bypass line 40L.Conversely, when one of the hydraulic actuators is operated, the hydraulic fluid discharged from the left main pump 14L flows into the hydraulic actuator to be operated via a control valve corresponding to the hydraulic actuator to be operated. The flow rate of the hydraulic fluid discharged from the left main pump 14L decreases or disappears to an extent reaching the left throttle 18L, and decreases the control pressure generated upstream of the left throttle 18L. As a result, the controller 30 increases the discharge amount of the left main pump 14L, circulates sufficient hydraulic fluid to the hydraulic actuator to be operated, and ensures the drive of the hydraulic actuator to be operated. The controller 30 similarly controls the discharge amount of the right main pump 14R.With the configuration described above, the hydraulic system of FIG. 2 can reduce wasteful power consumption of the main pump 14 in the standby state. The wasteful energy consumption includes pumping loss caused by the hydraulic fluid discharged from the main pump 14 into the center bypass line 40. The hydraulic system of FIG. 2 can reliably supply the necessary and sufficient hydraulic fluid from the main pump 14 to the hydraulic actuator to be operated when the hydraulic actuator is operated.Next, with reference to FIGS. 3A to 3D, a configuration in which the controller 30 automatically operates the actuator via the engine control function will be described. FIGS. 3A to 3D are views in which parts of the hydraulic system are extracted. Specifically, FIG. 3A is a view in which parts of the hydraulic system related to the operation of the arm cylinder 8 are extracted, and FIG. 3B is a view in which parts of the hydraulic system related to the operation of the swing hydraulic motor 2A are extracted. FIG. 3C is a view in which parts of the hydraulic system related to the operation of the boom cylinder 7 are extracted, and FIG. 3D is a view in which parts of the hydraulic system related to the operation of the bucket cylinder 9 are extracted.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.The proportional valve 31 functions as a control valve for engine control. The proportional valve 31 is located in a line connecting the pilot pump 15 and the shuttle valve 32, and is configured to change the flow area of the line. In the present embodiment, the proportional valve 31 operates in response to a control command output from the controller 30. Therefore, the controller 30 can supply the hydraulic fluid 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 operator's operation of the operating device 26.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 cause the pilot pressure generated by the operating device 26 and the pilot pressure generated by the proportional valve 31 to act on the pilot port of the corresponding control valve, whichever is higher.With this configuration, the controller 30 can operate the hydraulic actuator corresponding to the specific operating device 26 even when the specific operating device 26 is not operated.For example, as illustrated in FIG. 3A, the left operation lever 26L is used to operate the arm 5. Specifically, the left operation lever 26L uses the hydraulic fluid discharged from the pilot pump 15 to cause the pilot pressure corresponding to the operation in the front-rear direction to act on the pilot port of the control valve 176. Further, specifically, when the left operation lever 26L is operated in the arm closing direction (rearward direction), the pilot pressure corresponding to the operation amount acts on the right pilot port of the control valve 176L and the left pilot port of the control valve 176R. When the left operation lever 26L is operated in the arm opening direction (forward direction), the pilot pressure corresponding to the operation amount acts on the left pilot port of the control valve 176L and the right pilot port of the control valve 176R.The left operation lever 26L is provided with a switch NS. 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 another position in the cabin 10.The operation pressure sensor 29LA detects the contents of the operation of the left operation lever 26L by the operator in the longitudinal direction in the form of pressure, and outputs the detected value to the controller 30.The proportional valve 31AL operates in response to a current command output from the controller 30. The pilot pressure by the hydraulic fluid introduced from the pilot pump 15 into 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 is adjusted. The proportional valve 31AR operates in response to a current command output from the controller 30. Then, the pilot pressure is adjusted by the hydraulic fluid introduced from the pilot pump 15 into 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 may adjust the pilot pressure so that the control valves 176L and 176R may be stopped at any valve position.With this configuration, the controller 30 can supply the hydraulic fluid discharged 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 regardless of the arm closing operation by the operator. That is, the arm 5 can be automatically closed. The controller 30 can also supply the hydraulic fluid discharged 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 regardless of the arm opening operation by the operator. That is, the arm 5 can be automatically opened.As illustrated in FIG. 3B, the left operation lever 26L is also used for operating the swing mechanism 2. Specifically, the left operation lever 26L uses the hydraulic fluid discharged from the pilot pump 15 to apply a pilot pressure corresponding to the operation in the lateral direction to the pilot port of the control valve 173. More specifically, when the left operation lever 26L is operated in the left swing direction (left direction), the left pilot port of the control valve 173 is operated with a pilot pressure corresponding to the operation amount. When the left operation lever 26L is operated in the right swing direction (right direction), the right pilot port of the control valve 173 is operated with a pilot pressure corresponding to the operation amount.The operation pressure sensor 29LB detects the content of leftward operation of the left operation lever 26L by the operator in the leftward direction in the form of pressure, and outputs the detected value to the controller 30.The proportional valve 31BL operates in response to a current command output from the controller 30. The pilot pressure by the hydraulic fluid introduced from the pilot pump 15 into the left pilot port of the control valve 173 via the proportional valve 31BL and the shuttle valve 32BL is adjusted. The proportional valve 31BR operates in response to a current command output from the controller 30. The pilot pressure by the hydraulic fluid introduced from the pilot pump 15 into the right pilot port of the control valve 173 via the proportional valve 31BR and the shuttle valve 32BR is adjusted. The proportional valves 31BL and 31BR may adjust the pilot pressure so that the control valve 173 may be stopped at an arbitrary valve position.With this configuration, the controller 30 can supply the hydraulic fluid discharged from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31BL and the shuttle valve 32BL regardless of the leftward swing operation by the operator. That is, the swing mechanism 2 can be automatically swung leftward. The controller 30 can also supply the hydraulic fluid discharged from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31BR and the shuttle valve 32BR, regardless of the right swing operation by the operator. That is, the swing mechanism 2 can be automatically swung rightward.As shown in FIG. 3C, the right operation lever 26R is used to operate the boom 4. More specifically, the right operating lever 26R uses the hydraulic fluid discharged from the pilot pump 15 to apply a pilot pressure corresponding to the forward and reverse operation to the pilot port of the control valve 175. More specifically, when the right operation lever 26R is operated in the boom raising direction (rearward direction), a pilot pressure corresponding to the operation amount is applied to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. When the right operation lever 26R is operated in the boom lowering direction (forward direction), a pilot pressure corresponding to the operation amount is applied to the right pilot port of the control valve 175R.The operation pressure sensor 29RA detects the content of the operation of the right operation lever 26R in the longitudinal direction by the operator in the form of pressure, and outputs the detected value to the controller 30.The proportional valve 31CL operates in response to the current command output from the controller 30. Then, it adjusts the pilot pressure by the hydraulic fluid introduced from the pilot pump 15 into 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. The proportional valve 31CR operates in response to the current command output from the controller 30. Then, it adjusts the pilot pressure by the hydraulic fluid introduced from the pilot pump 15 into the left pilot port of the control valve 175L and the right pilot port of the control valve 175R via the proportional valve 31CR and the shuttle valve 32CR. The proportional valves 31CL and 31CR may adjust the pilot pressure so that the control valves 175L and 175R may be stopped at any valve position.With this configuration, the controller 30 can supply the hydraulic fluid 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 via the proportional valve 31CL and the shuttle valve 32CL regardless of the operation of the boom by the operator. That is, the boom 4 can be automatically raised. Also, the controller 30 can supply the hydraulic fluid 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 lowering movement of the boom by the operator. That is, the boom 4 can be automatically lowered.As illustrated in FIG. 3D, the right operation lever 26R is also used to operate the bucket 6. More specifically, the right operation lever 26R uses the hydraulic fluid discharged from the pilot pump 15 to apply a pilot pressure corresponding to the lateral operation to the pilot port of the control valve 174. More specifically, when the right operation lever 26R is operated in the blade closing direction (left direction), the control pressure corresponding to the operation amount is applied to the left control port of the control valve 174. When the right operation lever 26R is operated in the blade opening direction (right direction), the pilot pressure corresponding to the operation amount is applied to the right pilot port of the control valve 174.The operation pressure sensor 29RB detects the content of lateral operation of the right operation lever 26R by the operator in the form of pressure, and outputs the detected value to the controller 30.The proportional valve 31DL operates in response to a current command output from the controller 30. The pilot pressure by the hydraulic fluid introduced from the pilot pump 15 into the left pilot port of the control valve 174 via the proportional valve 31DL and the shuttle valve 32DL is adjusted. The proportional valve 31DR operates in response to a current command output from the controller 30. The pilot pressure by the hydraulic fluid introduced from the pilot pump 15 into the right pilot port of the control valve 174 via the proportional valve 31DR and the shuttle valve 32DR is adjusted. The proportional valves 31DL and 31DR may adjust the pilot pressure so that the control valve 174 may be stopped at any valve position.With this configuration, the controller 30 can supply the hydraulic fluid discharged 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 regardless of the blade closing operation by the operator. That is, the blade 6 can be automatically closed. The controller 30 can also supply the hydraulic fluid discharged 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 regardless of the blade opening operation by the operator. That is, the blade 6 can be automatically opened.The excavator 100 may be configured to automatically move the lower traveling body 1 forward and backward. In this case, the portion of the hydraulic system related to the operation of the left travel hydraulic motor 2ML and the portion of the hydraulic system related to the operation of the right travel hydraulic motor 2ML may be configured in the same manner as the portion of the hydraulic system related to the operation of the boom cylinder 7.Although the hydraulic operating lever having the hydraulic control circuit is described in Figs. 2 and 3A to 3D, an electric operating lever having an electric control circuit may be used instead of the hydraulic operating lever. In this case, the lever operation amount of the electric operation lever is input to the controller 30 as an electric signal. Between the pilot pump 15 and the pilot port of each control valve, a solenoid valve is arranged.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 the electric operation lever is performed, the controller 30 can move each control valve by controlling the solenoid valve by an electric signal corresponding to the operation amount of the lever to increase or decrease the control pressure. Note that each control valve may be constituted by an electromagnetic spool valve. In this case, the electromagnetic slide valve is operated in response to an electric signal of the controller 30 corresponding to the operation lever amount of the electric operation lever. Details about the electric operation lever will be described later.Next, the functions of the controller 30 will be described with reference to FIG. 4. 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 the posture detection device, the operation device 26, the object detection device 70, the imaging device 80, the switch NS, etc., perform various calculations, and output control commands to the proportional valve 31, the display device D 1, the sound output device D 2, etc. The posture detection device includes a boom angle sensor S 1, an arm angle sensor S 2, a bucket angle sensor S 3, a machine body inclination sensor S 4, and a swing angle speed sensor S 5.The controller 30 includes a posture recording unit 30A, a trajectory calculation unit 30B, an autonomous control unit 30C, an excavation reaction force calculation unit 30D, a state determination unit 30E, and an output unit 30F as functional elements. Each functional element may be constituted by hardware or software.The posture recording unit 30A is configured to record information on the posture of the excavator 100. In the present embodiment, the posture recording unit 30A records information on the posture of the excavator 100 when the switch NS in the RAM is pressed. More specifically, the attitude recording unit 30A records the output of the attitude detection device each time the switch NS is operated. The position recording unit 30A may be configured such that recording starts when the switch NS is pressed at a first point and ends when the switch NS is pressed at a second point. In this case, the posture recording unit 30A may repeatedly record information on the posture of the excavator 100 in a predetermined control cycle from the first point to the second point.The trajectory calculation unit 30B is configured to calculate a target trajectory that is a trajectory drawn from a predetermined portion of the excavator 100 when the excavator 100 is autonomously operated. The predetermined portion is, for example, a predetermined point on the rear 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 autonomously operates the excavator 100. More specifically, the trajectory calculation unit 30B calculates a target trajectory on the basis of information on the posture of the excavator 100 recorded by the posture recording unit 30A.The trajectory calculation unit 30B may calculate a target trajectory based on output from LIDAR as the object detection device 70, which is an example of the surrounding monitoring device. Alternatively, the trajectory calculation unit 30B may calculate a target trajectory on the basis of output of the imaging device 80 which is another example of the surrounding monitoring device. Alternatively, the trajectory calculation unit 30B may calculate a trajectory on the basis of information on the posture of the excavator 100 recorded by the posture recording unit 30A and output of the surrounding monitoring device.The autonomous control unit 30C is configured to operate the excavator 100 autonomously. In the present embodiment, when a predetermined start condition is satisfied, a predetermined portion of the excavator 100 is moved along the target trajectory calculated by the trajectory calculation unit 30B. Specifically, the excavator 100 is autonomously operated so that a predetermined portion of the excavator 100 moves along the target trajectory when the operation device 26 is operated with the switch NS pressed.For example, the excavator 100 may be autonomously operated such that the lower end of the bucket 6 moves along the target trajectory when the left operation lever 26L is operated in the right swing direction and the right operation lever 26R is operated in the boom upward direction while the switch NS is pressed. In this case, each of the left operation lever 26L and the right operation lever 26R can be operated by an arbitrary lever operation amount. Therefore, the operator can move the lower end of the bucket 6 at a predetermined moving speed along the trajectory without considering the lever operation amount. Alternatively, the moving speed of the bucket 6 may be configured to change in accordance with a change in the operation amount of the left operation lever 26L or the right operation lever 26R.For example, the autonomous control unit 30C may be configured to control at least one of the boom cylinder 7 and the swing hydraulic motor 2A such 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 in accordance with the raising speed of the boom 4. For example, the swing speed of the upper swing body 3 may be increased as the raising speed of the boom 4 increases. In this case, the boom 4 is raised at a speed corresponding to the lever operation amount of the right operation lever 26R in the boom raising direction, but the upper swing body 3 may swing at a speed different from the speed corresponding to the lever operation amount of the left operation lever 26L in the right swing direction.Alternatively, the autonomous control unit 30C may semi-automatically control the raising speed of the boom 4 in accordance with the swing speed of the upper swing body 3. For example, the raising speed of the boom 4 can be increased as the swing speed of the upper swing body 3 is increased. In this case, the upper swing body 3 may swing at a speed corresponding to the lever operation amount of the left operation lever 26L in the right swing direction, but the boom 4 may be raised at a speed different from the speed corresponding to the lever operation amount of the right operation lever 26R in the boom raising direction.Alternatively, the autonomous control unit 30C may semi-automatically control both the swing speed of the upper swing body 3 and the raising speed of the boom 4. In this case, the upper swing body 3 can swing at a speed different from the speed corresponding to the lever operation amount of the left operation lever 26L in the right swing direction. Similarly, the boom 4 can be raised at a speed different from the speed corresponding to the lever operation amount of the right operation lever 26R in the boom raising direction.The excavation reaction force calculation unit 30D calculates the excavation reaction force. The excavation reaction force is the reaction force of the excavation force, is the same magnitude as the excavation force, and is a force in a direction opposite to the excavation force. The excavation reaction force calculation unit 30D of the present embodiment automatically calculates the excavation reaction force based on the output of various sensors such as a cylinder pressure sensor and the posture of the excavator 100. 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. The excavation reaction force calculation unit 30D of the present embodiment may calculate the excavation reaction force each time an excavation operation is performed.The cylinder pressure sensor includes at least one of a boom rod pressure sensor S 7R, a boom bottom pressure sensor S 7B, an arm rod pressure sensor S 8R, an arm bottom pressure sensor S 8B, a bucket rod pressure sensor S 9R, and a bucket bottom pressure sensor S 9B.The condition determination unit 30E determines whether or not the variation in the excavation reaction force calculated by the excavation force calculation unit 30D satisfies a predetermined condition. The predetermined condition may be set in advance for the controller 30.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 force calculation unit 30D to the force feedback device 90.The output unit 30F outputs a message indicating that the state of the floor has changed when the state determination unit 30E determines that the change in the excavation reaction force satisfies a predetermined condition. Specifically, the output unit 30F may display, for example, a message on the display device D 1 requesting the operator to confirm the state of the floor or stop the excavation operation. The output unit 30F may also output a warning sound or the like via the sound output device D 2 or the like.Next, the operation of the excavator 100 according to the present embodiment will be described with reference to FIG. 5. FIG. 5 is a flowchart illustrating processing of control of Embodiment 1.FIG. 5 shows the processing of the controller 30 when an operator is on board the excavator 100 and the operator performs an operation for manually performing an excavation operation without using the machine control function.The controller 30 of the excavator 100 of the present embodiment starts an excavation operation in response to the operator's operation (step S 501).Subsequently, the controller 30 calculates the excavation reaction force in the excavation operation by the excavation reaction force calculation unit 30D (step S 502). Subsequently, the controller 30 outputs the calculated excavation reaction force to the force feedback device 90 via the output unit 30F, and displays feedback of a force feeling corresponding to the excavation reaction force to the operator via the force feedback device 90 (step S 503).Subsequently, the controller 30 determines whether the variation of the excavation reaction force satisfies a predetermined condition by the condition determination unit 30E (step S 504).Specifically, the state determination unit 30E may compare the excavation reaction force calculated in the excavation operation performed immediately before with the excavation reaction force calculated in step S 502 to determine whether or not the process of changing the excavation reaction force satisfies a predetermined condition. Further, the condition determination unit 30E may determine whether or not the process of changing the excavation reaction force satisfies a predetermined condition from the magnitude relationship between the excavation reaction force calculated in a certain period of time before the excavation operation is started in step S 501 and the excavation reaction force calculated in step S 502.When the process of changing the excavation reaction force does not satisfy the predetermined condition in step S 504, the controller 30 ends the process.When it is determined in step S 504 that the process of changing the excavation reaction force satisfies the predetermined condition, the controller 30 outputs a message via the output unit 30F (step S 505), and ends the process.Specifically, the output unit 30F may display, on the display device D 1, a message requesting completion of the excavation operation, a message requesting confirmation of the ground state, or the like.In the present embodiment, by outputting a notification for requesting completion of the excavation operation, continuation of the excavation operation in a state in which the excavation reaction force is high can be prevented. In other words, it is possible to prevent the work from continuing in a state where the load on the excavator 100 is high. Therefore, in the present embodiment, the work is performed in a state where the load of the excavator 100 is appropriate, and the work efficiency can be improved.Moreover, in the present embodiment, it is possible to cause the operator to confirm the ground state by displaying a message requesting confirmation of the ground state. Therefore, according to the present embodiment, it is possible to assist the operator in understanding the state of the floor. Moreover, according to the present embodiment, it is possible to assist the operator in detecting the hidden object when a hidden object or the like unexpected from the operator is located in the ground to be excavated.Here, the operation scene of the present embodiment will be described. The present embodiment can be used, for example, when prospecting is performed. The inspection is performed to confirm the position and depth of the concealed object by actually digging it out before construction so as not to damage it.In prospecting, instead of vertical immediate deep trench, the process of horizontal shallow trench is repeated to trench deeper gradually. In addition, in the conventional prospect, excavation by the excavator 100 and manual excavation must be repeatedly performed to avoid damage to the hidden object, which is time-consuming.By applying the present embodiment to prospecting, the operator who performs prospecting only needs to make manual excavation when, for example, obtaining a message requesting confirmation of the ground state. Therefore, when prospecting is performed using the present embodiment, it is not necessary to easily repeat prospecting and manual excavation, and the time and effort can be reduced.In other words, according to the present embodiment, upon inspection, the possibility of the presence of a hidden object can be displayed to the operator, and the time and effort of inspection can be reduced.It should be noted that in the example shown in FIG. 5, the case where the operator performs an operation for manually performing an excavation operation without using the machine control function has been described. However, the present embodiment may be applied to excavation work using the engine control function.In the present embodiment, the engine control function is activated when the switch NS is pressed. Therefore, in the processing shown in FIG. 5, when the change in the excavation reaction force satisfies a predetermined condition in the state where the engine control function is activated, the output unit 30F may cause the display device D 1 to display a message 1 instructing the interruption of the pressing of the switch NS. In other words, the output unit 30F may cause the operator to display a message prompting the operator to stop the excavation operation.Thus, in the present embodiment, it is possible to assist the operator to understand the state of the floor.(EMBODIMENT 2)An embodiment 2 will be described below with reference to the drawings. Embodiment 2 is different from Embodiment 1 in that the function of Embodiment 1 is provided in a remote control room of the excavator 100. Therefore, in the following description, functional configurations that are the same as those of Embodiment 1 are denoted by the same reference numerals used in the description of Embodiment 1, and the description thereof is omitted.FIG. 6 is a drawing showing an example of the system configuration of the remote control system of the excavator. The excavator remote control system SYS of the present embodiment includes an excavator 100, an auxiliary device 200, a management device 300, and a remote control room RC. The remote control system SYS is configured to support construction work with one or more excavators 100.The excavator 100 of the present embodiment acquires operation information indicating the operation state of the excavator 100. The operation information of the present embodiment may include sensor values output from an acceleration sensor and a gyro sensor provided on the hub, sensor values output from a cylinder pressure sensor, pilot pressure, and the like.In the remote control system SYS, the operation information acquired by the excavator 100 may be transmitted to the management device 300 and the remote control room RC. The operation information may be transmitted to both the management device 300 and the remote control space RC, or may be transmitted to the remote control space RC via the management device 300.The remote control system SYS may be composed of an excavator 100, an auxiliary device 200, and a plurality of management devices 300. The remote control system SYS may include the excavator 100 and the remote control room RC, but may not include the management device 300 and the auxiliary device 200.The support device 200 is typically a portable terminal device such as a laptop type computer terminal, a tablet terminal, or a smartphone worn by an operator at a construction site. The support device 200 may be a portable terminal carried by an operator of the excavator 100. The support device 200 may be a stationary terminal device.The management device 300 is typically a stationary terminal device such as a server computer (referred to as a cloud server) installed in a management center outside a construction site. The management device 300 may be, for example, an edge server installed on a construction site. The management device 300 may be a portable terminal device (e.g., a laptop computer terminal, a tablet terminal, or a mobile terminal such as a smartphone).At least one of the support device 200 and the management device 300 may include a monitor and an operation device for remote operation. In this case, an operator using the support device 200 or a manager using the management device 300 may operate the excavator 100 while using an operation device for remote operation. The remote operation operation device is communicatively connected to the controller 30 mounted on the excavator 100 via a wireless communication network such as a near field communication network, a mobile phone communication network, or a satellite communication network. The remote control space RC is an example of an external device that supports remote operation of the excavator 100. The remote control room RC includes a remote controller 30R, a sound output device A 2, an interior imaging device C 2, a display device RD, and a communication device T 2. The remote control room RC includes an operator seat DE on which the operator OP remotely controlling the excavator 100 sits.The remote controller 30R is a computing unit that performs various operations. In the present embodiment, like the controller 30, the remote controller 30R is configured by a microcomputer including a CPU and a memory. The various functions of the remote controller 30R are executed by the CPU by executing a program stored in the memory.The remote controller 30R of the present embodiment may have the same functions as those of the controller 30 of the excavator 100 of Embodiment 1. In this case, the controller 30 may not have the excavation reaction force calculation unit 30D, the state determination unit 30E, and the output unit 30F.The sound output device A 2 is configured to output sound. In the present embodiment, the sound output device A 2 is a speaker and can reproduce sound collected by a sound collecting device (not illustrated) mounted on the excavator 100.The interior imaging device C 2 is configured to image the interior of the remote control space RC. In the present embodiment, the interior imaging device C 2 is a camera installed in the remote control room RC, and is configured to image the operator OP seated on the operator seat DE.The communication device T 2 controls wireless communication with the communication device T 1 mounted on the excavator 100. In the present embodiment, the communication devices T 1 and T 2 mounted on the excavator 100 may transmit and receive information via a fifth generation (5G) cellular line, an LTE line, a satellite line, or the like.The operator seat DE has a structure similar to that of an operator seat installed in the cab 10 of an ordinary excavator. A drive lever and an accelerator pedal are arranged in front of the operator seat DE. Further, at the center of the upper surface of the right console box, a selection switch 75 is disposed. Each of the left operation lever, the right operation lever, the travel lever, and the accelerator pedal constitutes an operation device 26E.Further, the operation device 26E is provided with a force feedback device 90E for giving a feeling 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. The force feedback device 90E may include a vibration device for vibrating the operator seat DE according to the excavation reaction force.The selector 75 is a selector for adjusting the rotational speed of the motor 11, and is configured such that the rotational speed of the motor can be switched in four stages, for example.Specifically, the selector 75 is configured such that the rotation speed of the engine can be switched in four stages of an SP mode, an H mode, an A mode, and an idle mode. The selector 75 transmits data related to the setting of the rotational speed of the motor to the controller 30.The SP mode is a speed mode selected when the operator OP wants to prioritize the working amount and uses the highest engine speed. The H mode is a speed mode selected when the operator OP wants to achieve both the working amount and the fuel consumption, and in which the second highest engine speed is used. The A mode is a speed mode selected when the operator OP wants to operate the excavator at a low noise level while prioritizing fuel consumption, and the third highest engine speed is used. The idle mode is a speed mode selected when the operator OP wants to idle the engine and in which the lowest engine speed is used. The motor 11 is controlled at a constant speed to the motor speed selected via the selector 75.The operation device 26E is provided with an operation pressure sensor 29A for detecting the operation content of the operation device 26E. The operation pressure sensor 29A is, for example, an inclination sensor for detecting the inclination angle of the operation lever or an angle sensor for detecting the swing angle of the operation lever about the swing axis. The operation pressure sensor 129A may be configured of another sensor, such as a pressure sensor, a current sensor, a voltage sensor, or a distance sensor. The operation pressure sensor 29A outputs information on the detected operation content of the operation 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 to the excavator 100. The operation pressure sensor 29A may be configured to generate an operation signal. In this case, the operation pressure sensor 29A can output an operation signal to the communication device T 2 without passing through the remote controller 30R.The display device RD is configured to display information on the situation around the excavator 100. In the present embodiment, the display device RD is a multidisplay that is configured of nine monitors in three vertical stages and three horizontal rows and is configured to display the state of the space in front, left, and right of the excavator 100. Each monitor is a liquid crystal monitor, an organic EL monitor, or the like. However, the display device RD may be configured of one or more curved monitors or a projector.The display device RD may be configured to display the state of the space in front, left, right, and rear of the excavator 100.The display device RD may display a message output from the output unit 30F of the remote controller 30R.The display device RD may be a display device that the operator OP can wear. The display device RD may be, for example, a head-mounted display and configured to transmit and receive information to and from the remote controller 30R through wireless communication. The head-mounted display may be wired to the remote controller 30R. The head-worn display may be a transmissible head-worn display or a nontransmissive head-worn display. The head-worn display may be a single-eye head-worn display or a binocular head-worn display.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 environment of the excavator 100 as if he or she was in the cab 10 of the excavator 100 even though the operator is in the remote operation room RC.Next, the processing of the remote controller 30R in the remote control space RC of the present embodiment will be described with reference to FIG. 7. FIG. 7 is a flowchart illustrating processing of remote control of Embodiment 2.The remote controller 30R of the present embodiment causes the excavator 100 to start an excavation operation in response to an operation by the operator OP (step S 701). Subsequently, the remote controller 30R acquires operation information from the excavator 100 (step S 702).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 S 703), and the process proceeds to step S 704.The operations from step S 704 to step S 706 in FIG. 7 are the same as those in steps S 503 and S 506 in FIG. 5, except that the output destination of the message in step S706 is the display device RD, and thus the description thereof is omitted.As described above, in the present embodiment, even in the remote control space RC for remotely controlling the excavator 100, the excavation reaction force of the excavator 100 can be used to assist the operator OP to understand the state of the ground.Further, in the present embodiment, the excavation reaction force is fed back to the operator OP via the operation device 26E and the operator seat DE of the remote control room RC. The excavation reaction force is fed back to the operator OP.Therefore, in the present embodiment, not only the change in the state of the ground but also the feeling when the body of the excavator 100 is lifted and the feeling when the body of the excavator 100 is pulled are fed back to the operator OP.Therefore, in the present embodiment, the operator OP can feel the feeling close to the feeling of being on the excavator 100 at the construction site, and it is possible to assist the operator OP to understand the load of the excavator 100 during work.In the example of FIG. 7, the output destination of the message is set to the display device RD by the output unit 30F, but the present invention is not limited thereto. The notification by the output unit 30F may be output to the support device 200, for example.More specifically, in the present embodiment, when the state 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 the completion of the excavation operation and cause the display device of the support device 200 to display a message instructing the confirmation of the state of the floor.In this way, for example, when exploratory excavation is performed using the remote control system SYS, the operator OP of the remote control room RC and the operator who assists the work at the construction site can cooperate to confirm the state of the ground. Therefore, according to the present embodiment, the detection of hidden objects can be supported.In the above-described embodiment, a hydraulic operating device is used as the operating device 26, but an electric operating device may be used. FIG. 8 is a drawing showing a configuration example of an operation system including an electric operation device. Specifically, the operation system of FIG. 8 is an example of a boom operation system, and is mainly configured of 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 the boom raising operation, and a solenoid valve 62 for the boom lowering operation. The operation system of FIG. 8 can be similarly applied to an arm operation system, a bucket operation system, and the like.The pilot pressure controlled valve 17 includes control valves 175L, 175R for the boom cylinder 7. the solenoid valve 60 is configured to adjust the flow 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 adjust the flow area of the oil passage connecting the pilot pump 15 to the right pilot port of the control valve 175R.When the manual operation is performed, the controller 30 generates a boom raising operation signal (electric signal) or a boom lowering operation signal (electric signal) in accordance with an operation signal (electric signal) output from the operation signal generator of the right operation lever 26R. The operation signal output from the operation signal generator of the right operation lever 26R is an electric signal that changes in accordance with the operation amount and the operation direction of the right operation lever 26R.Specifically, when the right operation lever 26R is operated in the boom raising direction, the controller 30 outputs a boom raising operation signal (electric signal) corresponding to the lever operation amount to the solenoid valve 60. The solenoid valve 60 adjusts the flow path area in accordance with the boom raising operation signal (electric 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 (electric signal) corresponding to the lever operation amount to the solenoid valve 62. The solenoid valve 62 adjusts the flow path area in accordance with the boom lowering operation signal (electric signal) and controls the pilot pressure acting on the right pilot port of the control valve 175R.When the automatic control is executed, the controller 30 generates a boom raising operation signal (electric signal) or a boom lowering operation signal (electric signal) in accordance with the correction operation signal (electric signal) instead of the operation signal output from the operation signal generator of the right operation lever 26R. The correction operation signal may be an electric signal generated by the controller 30 or an electric signal generated by a control device other than the controller 30.In the above-described embodiment, the excavator 100 is used as an example of a work machine that uses the excavation reaction force in excavation work, but the present invention is not limited thereto. The work machine of the present embodiment can be applied to any work machine as long as the work object is the ground and the work machine receives the work reaction force. In the present embodiment, for example, the present invention may be applied to a work machine that receives a reaction force when the soil is pressed and the soil is compacted, instead of the excavation reaction force.It should be understood that the invention is not limited to the embodiment described above, but can be modified in various forms based on the spirit of the invention. Moreover, the modifications are included in the scope of the invention.DESCRIPTION OF THE REFERENCE NUMERALS1 Lower traveling body 2 Swing mechanism 3 Upper rotating body 4 Boom 5 Arm 6 Bucket 30 Controller 100 Excavator

Claims

A work machine comprising: a lower traveling body; an upper rotating body rotatably mounted on the lower traveling body; a sensor mounted on the upper rotating body; and a control device configured to calculate an excavation reaction force generated by an excavation operation each time the excavation operation is performed based on the output of the sensor, and output a message indicating that a state of the ground adjacent to the ground excavated by the excavation operation is different from the state of the other ground when change in the excavation reaction force satisfies a predetermined condition.The work machine according to claim 1, wherein the predetermined condition is that the excavation reaction force changes by a certain amount or more within a predetermined period.The work machine of claim 1, wherein the predetermined condition is that the excavation reaction force increases exponentially.The work machine according to claim 1, wherein the control device is configured to cause a display device to display a message instructing termination of the excavation operation as the message.The work machine according to claim 1, wherein the control device is configured to cause a display device to display a message requesting confirmation of the state of the ground as the message.The working machine according to claim 1, wherein the state of the ground adjacent to the ground excavated by the excavation operation is different from the state of the other ground, comprises a state that there is a hidden object in the ground adjacent to the ground excavated by the excavation operation, that there is a hollow in the ground adjacent to the ground excavated by the excavation operation, and that there is an object softer than the ground in the ground adjacent to the ground excavated by the excavation operation.The work machine according to claim 1, wherein the other ground comprises the ground on which the excavation work has already been performed.A remote control system for a work machine, comprising: the work machine having a lower travel body, an upper swing body rotatably mounted on the lower travel body, a appendix attached to the upper swing body, and a sensor attached to the upper swing body; and an external device configured to assist remote control of the work machine, wherein the external device includes a control device for calculating an excavation reaction force generated by an excavation operation each time the excavation operation is performed based on an output signal of the sensor, and for outputting a message indicating that a state of the ground adjacent to the ground excavated by the excavation operation is different from the state of the other ground when change of the excavation reaction force satisfies a predetermined condition.

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