Work machine and remote control system for work machine

Abstract

A work machine according to an embodiment includes: a lower traveling body; an upper turning body turnably mounted on the lower traveling body; an attachment attached to the upper turning body; a work tool provided on a distal end of the attachment; a storage configured to store reference surface information representing a shape of a surface after being worked; and a controller including a processor and a memory and configured to perform control to move the work tool along a region that is extended from the surface represented by the reference surface information.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation application of International Application No. PCT / JP2024 / 034143, filed on September 25, 2024, and designating the U.S., which is based upon and claims priority to Japanese Patent Application No. 2023-167694, filed on September 28, 2023, the entire contents of which are incorporated herein by reference.BACKGROUNDTECHNICAL FIELD

[0002] The present invention relates to a work machine and a remote control system for a work machine.BACKGROUND ART

[0003] Conventionally, there has been known a work machine that performs control for moving a predetermined part of a work tool along a design surface upon receiving an operation from an operator. For example, when moving the predetermined part along the design surface, a proposed technique switches between a normal control mode and a low-speed control mode in accordance with an angle at which the predetermined part is present at the boundary between two design surfaces.SUMMARY

[0004] Conventional work machines have a function for moving a work tool to be in contact with one of a plurality of surfaces in accordance with the position of the work tool. Therefore, if the work tool is close to another surface at the same time when performing work on the one of the plurality of surfaces, control might be performed to move the work tool to be in contact with the another surface regardless of the intention of the operator. Therefore, a work machine having a function for moving the work tool might have difficulty positioning the work tool when performing work along a desired surface.

[0005] An embodiment of the present invention provides a technique for improving operability when performing work with a work tool.

[0006] An excavator according to an embodiment of the present invention includes: a lower traveling body; an upper turning body rotatably mounted on the lower traveling body; an attachment attached to the upper turning body; a work tool provided on a distal end of the attachment; a storage configured to store reference surface information representing a shape of a surface after being worked; and a controller including a processor and a memory and configured to perform control to move the work tool along a region that is extended from the surface represented by the reference surface information.

[0007] According to an embodiment of the present invention, operability when performing work with a work tool is improved.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a side view of an excavator according to a first embodiment;

[0009] FIG. 2 is a diagram showing a configuration example of a drive control system of the excavator according to the first embodiment;

[0010] FIG. 3 is a diagram showing a configuration example of a hydraulic system mounted on the excavator according to the first embodiment;

[0011] FIG. 4 is a conceptual diagram showing an example of a target work surface on which the excavator according to the first embodiment performs work;

[0012] FIG. 5 is a diagram showing a movement locus of a bucket when a conventional machine control function is executed on a target work surface;

[0013] FIG. 6 is a diagram showing a guide surface set by control from a machine control function unit according to the first embodiment, and movement of a bucket along the guide surface;

[0014] FIG. 7 is a diagram showing a transition of screen views displayed until the guide surface is set by the machine control function unit according to the first embodiment;

[0015] FIG. 8 is a diagram showing a guide surface set by control from the machine control function unit according to the first embodiment, and movement of the bucket along the guide surface;

[0016] FIG. 9 is a diagram showing the guide surface set by control from the machine control function unit according to the first embodiment;

[0017] FIG. 10 is a flowchart showing a processing procedure performed by the machine control function unit according to the first embodiment;

[0018] FIG. 11 is an explanatory diagram showing a control procedure performed by the machine control function unit according to a modification of the first embodiment; and

[0019] FIG. 12 is a schematic view showing an example of a remote control system according to a second embodiment.DETAILED DESCRIPTION OF THE INVENTION

[0020] Embodiments of the present invention will be described below with reference to the drawings. Further, the embodiments described below are not intended to limit the invention but are exemplary, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. In the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof may be omitted.

[0021] In the following embodiments of the present invention, an example using an excavator as an example of a work machine will be described. However, the present invention is not limited to an excavator. The present invention may be applied to construction machines, standard machines, applied machines, forestry machines, or conveyance machines based on the hydraulic excavator.First Embodiment

[0022] An outline of an excavator 100 according to the present embodiment will be described with reference to FIG. 1. FIG. 1 is a side view of the excavator 100 as a work machine according to the present embodiment.

[0023] The excavator 100 according to the present embodiment includes a lower traveling body 1, an upper turning body 3 mounted on the lower traveling body 1 turnably via a turning mechanism 2, a boom 4, an arm 5, and a bucket 6, which constitute an attachment (working machine), and a cabin 10.

[0024] The lower traveling body 1 causes the excavator 100 to travel with a pair of left and right crawlers hydraulically driven by traveling hydraulic motors 2ML and 2MR (see FIG. 2 described later), respectively. That is, the pair of traveling hydraulic motors 2ML and 2MR (examples of a traveling motor) drive the lower traveling body 1 (crawlers) as a driven part.

[0025] The upper turning body 3 turns with respect to the lower traveling body 1 by being driven by a turning hydraulic motor 2A (see FIG. 2 described later). That is, the turning hydraulic motor 2A is a turning driving part for driving the upper turning body 3 as a driven part, and can change the direction of the upper turning body 3.

[0026] The upper turning body 3 may be electrically driven by an electric motor (hereinafter, “turning electric motor”) instead of the turning hydraulic motor 2A. That is, like the turning hydraulic motor 2A, the turning electric motor is a turning driving part for driving the upper turning body 3 as a driven part, and can change the direction of the upper turning body 3.

[0027] The boom 4 is pivotally attached to the center of the front part of the upper turning body 3 to be at any angle of depression or elevation. The arm 5 is pivotally attached to the distal end of the boom 4 in a vertically pivotal manner. The bucket 6 as an end attachment is pivotally attached to the distal end of the arm 5 in a vertically pivotal manner. The boom 4, the arm 5, and the bucket 6 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 as hydraulic actuators, respectively.

[0028] The bucket 6 is an example of the end attachment (work tool) provided at the distal end of the arm 5, and is specifically an excavation bucket, yet may be a skeleton bucket or a gravel removal bucket. The bucket 6 may include a bucket tilt mechanism.

[0029] The cabin 10 as a driver's chamber is provided on the upper turning body 3, and is mounted with a power source, such as an engine 11 or the like. An operation device 26, a controller 30, and the like are provided inside the cabin 10. Image capture devices S6 or the like are attached to the upper turning body 3.

[0030] The image capture devices S6 capture images of the surrounding of the excavator 100. The image capture devices S6 include a camera S6F for capturing images of the view in front of the excavator 100, a camera S6L for capturing images of the view on the left side of the excavator 100, a camera S6R for capturing images of the view on the right side of the excavator 100, and a camera S6B for capturing images of the view on the back of the excavator 100.

[0031] The camera S6F is attached, for example, to the ceiling of the cabin 10, that is, to the interior of the cabin 10. The camera S6F may be attached to the outside of the cabin 10, such as the roof of the cabin 10, the side surface of the boom 4, and the like. The camera S6L is attached to the left end of the upper surface of the upper turning body 3, the camera S6R is attached to the right end of the upper surface of the upper turning body 3, and the camera S6B is attached to the rear end of the upper surface of the upper turning body 3.

[0032] Each of the image capture devices S6 (cameras S6F, S6B, S6L, and S6R) is, for example, a monocular wide-angle camera having a very wide angle of view. Each of the image capture devices S6 may be a stereo camera, a range camera, or the like. Images captured by the image capture devices S6 are acquired by the controller 30.

[0033] The image capture devices S6 as spatial recognition devices may function as object detection devices. In this case, the image capture devices S6 may detect an object existing around the excavator 100. Examples of the object to be detected may include a person, an animal, a vehicle, a construction machine, a building, a hole, and the like. The image capture devices S6 may also calculate the distance from the image capture devices S6 or the excavator 100 to a recognized object. Examples of the image capture devices S6 as the object detection devices include a stereo camera, a range sensor, and the like. The spatial recognition devices are, for example, monocular cameras including an imaging element, such as a CCD, a CMOS, and the like, and output captured images to a display device 60. The spatial recognition devices may be configured to calculate the distance from the spatial recognition devices or the excavator 100 to a recognized object. In addition to the image capture devices S6, another object detection device, such as, for example, an ultrasonic sensor, a millimeter-wave radar, a LIDAR, an infrared sensor, and the like, may be provided as a spatial recognition device. When using a millimeter-wave radar, an ultrasonic sensor, a laser radar, or the like as a spatial recognition device, many signals (such as laser beams) may be radiated to an object and reflected signals thereof may be received, to thereby detect the distance and the direction of the object based on the reflected signals.

[0034] The operation device 26 is a device used by an operator to operate the actuators. The operation device 26 includes, for example, an operation lever and an operation pedal. The actuator includes at least one of a hydraulic actuator or an electric actuator.

[0035] An input device 62 is provided within reach of a seated operator in the cabin 10, receives various operation inputs from the operator, and outputs signals corresponding to the operation inputs to the controller 30. The input device 62 includes a touch panel or the like that is mounted on a display of the display device 60 for displaying various information images. The signals corresponding to the contents of the operations to the input device 62 are acquired by the controller 30.

[0036] The display device 60 is provided at a location at which the display device 60 is easily visible from a seated operator in the cabin 10, and displays various information images under the control from the controller 30. The display device 60 may be connected to the controller 30 through an on-board communication network, such as a Controller Area Network (CAN) and the like, or may be connected to the controller 30 through a one-to-one dedicated line.

[0037] A communication device T1 communicates with an external device through a predetermined network including a mobile communication network with base stations at the edge, a satellite communication network, an Internet network, and the like. The communication device T1 is, for example, a mobile communication module supporting a mobile communication protocol, such as Long Term Evolution (LTE), 4th Generation (4G), 5th Generation (5G), or the like, a satellite communication module for connecting to a satellite communication network, or the like.

[0038] The controller (control device) 30 is a control device for controlling the excavator 100.

[0039] For example, the controller 30 is mainly composed of a computer including a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), a nonvolatile auxiliary storage device, various input / output interfaces, and the like. The controller 30 reads out a program from the non-volatile storage device, loads it into a volatile storage device, and causes the CPU to execute the program, to thereby realize various functions. The various functions include, for example, a machine guidance function for guiding an operator about manual operations of the excavator 100. The controller 30 may include a contact avoidance function for automatically or autonomously operating or stopping the excavator 100 in order to avoid contact between the excavator 100 and an object existing in a monitoring range around the excavator 100.

[0040] For example, the controller 30 sets a target rotational speed based on an operation performed by an operator or the like and performs drive control for rotating the engine 11 at a constant speed.

[0041] The controller 30 further includes, for example, a machine control function unit 50 having a function for automatically assisting manual operations on the excavator 100 performed by an operator via the operation device 26. The machine control function unit 50 will be described later.

[0042] Part of the functions of the controller 30 may be implemented by another controller (control device). That is, functions of the controller 30 may be implemented in the form of being distributed across a plurality of controllers. For example, the machine guidance function and the machine control function unit 50 may be implemented by dedicated controllers (control devices).

[0043] A boom angle sensor S1 is attached to the boom 4, and detects an angle of depression or elevation (hereinafter referred to as “boom angle”) of the boom 4 with respect to the upper turning body 3, which is, for example, an angle that, when viewed in a side view, is formed by a straight line connecting the fulcrums of both ends of the boom 4 with respect to a turning plane in which the upper turning body 3 turns. The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an Inertial Measurement Unit (IMU), and the like. The boom angle sensor S1 may also include a potentiometer using a variable resistor, a cylinder stroke sensor for detecting a stroke amount of the hydraulic cylinder (boom cylinder 7) corresponding to the boom angle, and the like. The same applies to an arm angle sensor S2 and a bucket angle sensor S3. A detection signal corresponding to the boom angle detected by the boom angle sensor S1 is acquired by the controller 30.

[0044] The arm angle sensor S2 is attached to the arm 5 and detects a pivoting angle (hereinafter referred to as “arm angle”) of the arm 5 with respect to the boom 4, which is, for example, an angle that, in a side view, is formed by a straight line connecting the fulcrums of both ends of the arm 5 with respect to the straight line connecting the fulcrums of both ends of the boom 4. A detection signal corresponding to the arm angle detected by the arm angle sensor S2 is acquired by the controller 30.

[0045] The bucket angle sensor S3 is attached to the bucket 6 and detects a pivoting angle (hereinafter referred to as “bucket angle”) of the bucket 6 with respect to the arm 5, which is, for example, an angle that, in a side view, is formed by a straight line connecting a fulcrum and the distal end (the tip of a claw) of the bucket 6 with respect to the straight line connecting the fulcrums of both ends of the arm 5. A detection signal corresponding to the bucket angle detected by the bucket angle sensor S3 is acquired by the controller 30.

[0046] A machine body inclinometer (an example of an attitude detection unit) S4 detects an inclination state of the machine body (the upper turning body 3 or the lower traveling body 1) with respect to the horizontal plane. The machine body inclinometer S4 is attached to, for example, the upper turning body 3, and detects inclination angles (hereinafter, “front-rear inclination angle” and “left-right inclination angle”) of the excavator 100 (that is, the upper turning body 3) about two axes, which are the front-rear direction and the left-right direction. The machine body inclinometer S4 may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an IMU, and the like. A detection signal corresponding to the inclination angles (the front-rear inclination angle and the left-right inclination angle) detected by the machine body inclinometer S4 is acquired by the controller 30.

[0047] The turning angle sensor S5 outputs detection information related to the turning state of the upper turning body 3. The turning angle sensor S5 detects, for example, a turning angular velocity and a turning angle of the upper turning body 3. The turning angle sensor S5 may include, for example, a gyro sensor, a resolver, a rotary encoder, and the like. A detection signal corresponding to the turning angle and the turning angular velocity of the upper turning body 3 detected by the turning angle sensor S5 is acquired by the controller 30.

[0048] A boom rod pressure sensor S7R and a boom bottom pressure sensor S7B are attached to the boom cylinder 7. An arm rod pressure sensor S8R and an arm bottom pressure sensor S8B are attached to the arm cylinder 8. A bucket rod pressure sensor S9R and a bucket bottom pressure sensor S9B are attached to the bucket cylinder 9. The boom rod pressure sensor S7R, the boom bottom pressure sensor S7B, the arm rod pressure sensor S8R, the arm bottom pressure sensor S8B, the bucket rod pressure sensor S9R and the bucket bottom pressure sensor S9B are also collectively referred to as “cylinder pressure sensors”.

[0049] The boom rod pressure sensor S7R detects the pressure of a rod side oil chamber in the boom cylinder 7 (hereinafter referred to as “boom rod pressure”), and the boom bottom pressure sensor S7B detects the pressure in a bottom side oil chamber of the boom cylinder 7 (hereinafter referred to as “boom bottom pressure”). The arm rod pressure sensor S8R detects the pressure in a rod side oil chamber of the arm cylinder 8 (hereinafter referred to as “arm rod pressure”), and the arm bottom pressure sensor S8B detects the pressure in a bottom side oil chamber of the arm cylinder 8 (hereinafter referred to as “arm bottom pressure”). The bucket rod pressure sensor S9R detects the pressure in a rod side oil chamber of the bucket cylinder 9 (hereinafter referred to as “bucket rod pressure”), and the bucket bottom pressure sensor S9B detects the pressure in a bottom side oil chamber of the bucket cylinder 9 (hereinafter referred to as “bucket bottom pressure”).

[0050] A positioning device PS measures the position and the direction of the upper turning body 3. The positioning device PS is, for example, a Global Navigation Satellite System (GNSS) compass, and detects the position and the direction of the upper turning body 3, and a detection signal corresponding to the position and the direction of the upper turning body 3 is acquired by the controller 30. The function for detecting the direction of the upper turning body 3, among the functions of the positioning device PS, may be replaced by an orientation sensor attached to the upper turning body 3.Drive Control System of Excavator

[0051] FIG. 2 is a diagram showing a configuration example of a drive control system of the excavator 100 shown in FIG. 1. In FIG. 2, a mechanical power transmission system is indicated by double lines, hydraulic oil lines are indicated by thick solid lines, pilot lines are indicated by broken lines, and an electric drive / control system is indicated by dotted lines.

[0052] A drive system of the excavator 100 according to the present embodiment includes the engine 11, regulators 13, main pumps 14, and a control valve unit 17. A hydraulic drive system of the excavator 100 according to the present embodiment includes the hydraulic actuators, such as the traveling hydraulic motors 2ML and 2MR, the turning hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the like for hydraulically driving the lower traveling body 1, the upper turning body 3, the boom 4, the arm 5, and the bucket 6, respectively, as described above. These hydraulic actuators are driven by a hydraulic oil discharged from the main pumps 14.

[0053] The engine 11 is a main power source in the hydraulic drive system, and is mounted, for example, in the back of the upper turning body 3. Specifically, the engine 11 rotates constantly at a predetermined target rotational speed under direct or indirect control from the controller 30 described later, and drives the main pumps 14 and a pilot pump 15. The engine 11 is, for example, a diesel engine fueled by light oil.

[0054] The regulators 13 control the discharge amounts of the main pumps 14. For example, the regulators 13 adjust the angles (tilt angles) of swash plates of the main pumps 14 in accordance with control commands from the controller 30. The regulators 13 include, for example, regulators 13L and 13R as will be described later.

[0055] The main pumps 14 are mounted, for example, in the back of the upper turning body 3 like the engine 11, and supply the hydraulic oil to the control valve unit 17 through high-pressure hydraulic lines. The main pumps 14 are driven by the engine 11 as described above. The main pumps 14 are, for example, variable-displacement hydraulic pumps, and the discharge flow rates (discharge pressures) of the main pumps 14 are controlled in response to their piston stroke length being adjusted by the tilt angles of the swash plates being adjusted by the regulators 13 under control from the controller 30 as described above. The main pumps 14 include, for example, main pumps 14L and 14R as described later.

[0056] The control valve unit 17 is a hydraulic control device for controlling a hydraulic system of the excavator 100. In the present embodiment, the control valve unit 17 includes control valves 171 to 176. The control valve unit 17 is configured to supply the hydraulic oil discharged from the main pumps 14 selectively to one or a plurality of hydraulic actuators via the control valves 171 to 176.

[0057] The control valves 171 to 176 control the flow rate of the hydraulic oil flowing from the main pumps 14 to the hydraulic actuators and the flow rate of the hydraulic oil flowing from the hydraulic actuators to a hydraulic oil tank. The hydraulic actuators include the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the traveling hydraulic motors 2ML and 2MR, and the turning hydraulic motor 2A. More specifically, the control valve 171 corresponds to the left traveling hydraulic motor 2ML, the control valve 172 corresponds to the right traveling hydraulic motor 2MR, and the control valve 173 corresponds to the turning hydraulic motor 2A. The control valve 174 corresponds to the bucket cylinder 9, the control valves 175 corresponds to the boom cylinder 7, and the control valves 176 corresponds to the arm cylinder 8.

[0058] The pilot pump 15 is an example of a pilot pressure generation device, and is configured to supply the hydraulic oil to the hydraulic control devices through the pilot lines. In the present embodiment, the pilot pump 15 is a fixed-displacement hydraulic pump. However, the pilot pressure generation device may be implemented by the main pumps 14. That is, the main pumps 14 may have a function for supplying the hydraulic oil to the various hydraulic control devices through the pilot lines in addition to the function for supplying the hydraulic oil to the control valve unit 17 through the hydraulic oil lines. In this case, the pilot pump 15 may be omitted.

[0059] The operation device 26 is an example of an electric operation device used by an operator to operate the actuators. The actuators include at least one of hydraulic actuators or electric actuators.

[0060] Discharge pressure sensors 28 are configured to detect the discharge pressures of the main pumps 14. In the present embodiment, the discharge pressure sensors 28 output the detected values to the controller 30.

[0061] Operation sensors 29 are configured to detect the contents of operations performed by the operator using the operation device 26. In the present embodiment, the operation sensors 29 detect the direction in which the operation device 26 is operated, and the amount by which the operation device 26 is operated, both corresponding to any of the actuators, and output the detected values to the controller 30. In the present embodiment, the controller 30 controls the opening area of a proportional valve 31 in accordance with outputs from the operation sensors 29. The controller 30 supplies the hydraulic oil discharged from the pilot pump 15 to a pilot port of a corresponding control valve in the control valve unit 17. The pressure (pilot pressure) of the hydraulic oil supplied to each pilot port is, in principle, a pressure corresponding to the direction in which the operation device 26 is operated and the amount by which the operation device 26 is operated, both corresponding to each hydraulic actuator. In this way, the operation device 26 is configured to supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of a corresponding control valve in the control valve unit 17.

[0062] The proportional valve 31 functioning as a control valve for machine control is provided on a pipeline connecting the pilot pump 15 and the pilot ports of the control valves in the control valve unit 17, and is configured to change the flow path area of the pipeline. In the present embodiment, the proportional valve 31 operates in accordance with a control command output from the controller 30.

[0063] The controller 30 controls opening and closing of the proportional valve 31 in accordance with a signal that is input from the operation sensors 29, and is configured to supply the hydraulic oil discharged from the pilot pump 15 to the pilot ports of corresponding control valves 171 to 176 in the control valve unit 17 through the pilot lines. In the case where the operator operates the operation device 26, the pressure (pilot pressure) of the hydraulic oil supplied to each pilot port is a pressure corresponding to the direction in which the operation device 26 is operated and the amount by which the operation device 26 is operated, both corresponding to each hydraulic actuator. That is, the proportional valve 31 adjusts the pilot pressures supplied to the pilot ports of the control valves 171 to 176 in order to switch between routes of supply by the control valves 171 to 176 based on signals received from the operation sensors 29.

[0064] The controller 30 can cause a pilot pressure generated by the proportional valve 31 to be applied to the pilot port of a corresponding control valve. Therefore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of any control valve in the control valve unit 17 via the proportional valve 31 independently of an operation performed by the operator on the operation device 26.

[0065] With this configuration, the controller 30 can operate any hydraulic actuator that corresponds to any specific operation device 26 even when that operation device 26 is not operated. The controller 30 can forcibly stop the operation of any hydraulic actuator that corresponds to any specific operation device 26 even when that specific operation device 26 is being operated.

[0066] For example, when the excavator 100 is set to perform autonomous control, the controller 30 performs control for operating various elements of the excavator 100 by setting one or more selected from a target turning angle for the upper turning body 3, a target angle for each of the upper turning body 3, the boom 4, the arm 5, and the bucket 6, and a target rotational speed for the engine 11 based on the operations to be performed under the autonomous control.

[0067] For example, the controller 30 outputs a control command to the regulators 13 as necessary to change the discharge amounts of the main pumps 14.Hydraulic System of Excavator

[0068] Next, a configuration example of the hydraulic system mounted on the excavator 100 will be described with reference to FIG. 3. FIG. 3 is a diagram showing a configuration example of the hydraulic system mounted on the excavator 100. In FIG. 3, the mechanical power transmission system, the hydraulic oil lines, the pilot lines, and the electric control system are indicated by double lines, solid lines, broken lines, and dotted lines, respectively.

[0069] The hydraulic system of the excavator 100 mainly includes the engine 11, the regulators 13, the main pumps 14, the pilot pump 15, the control valve unit 17, the operation device 26, the discharge pressure sensors 28, the operation sensors 29, the controller 30, and the like.

[0070] In FIG. 3, the hydraulic system is configured to circulate the hydraulic oil from the main pumps 14 driven by the engine 11 to the hydraulic oil tank through center bypass pipelines 40 or parallel pipelines 42.

[0071] The main pumps (hydraulic pumps) 14 are configured to supply the hydraulic oil to the control valve unit 17 through the hydraulic oil lines. In the present embodiment, the main pumps 14 are swash plate-type variable-displacement hydraulic pumps.

[0072] In the present embodiment, the control valve unit 17 includes the control valves 171 to 176. The control valves 175 include a control valve 175L and a control valve 175R, and the control valves 176 include a control valve 176L and a control valve 176R. The control valve unit 17 is configured to selectively supply the hydraulic oil discharged from the main pumps 14 to one or a plurality of hydraulic actuators via the control valves 171 to 176.

[0073] The main pumps 14 include the left main pump 14L and the right main pump 14R. The left main pump 14L circulates the hydraulic oil to the hydraulic oil tank through a left center bypass pipeline 40L or a left parallel pipeline 42L, and the right main pump 14R circulates the hydraulic oil to the hydraulic oil tank through a right center bypass pipeline 40R or a right parallel pipeline 42R.

[0074] The left center bypass pipeline 40L is a hydraulic oil line passing through the control valves171, 173, 175L, and 176L disposed in the control valve unit 17. The right center bypass pipeline 40R is a hydraulic oil line passing through the control valves 172, 174, 175R, and 176R disposed in the control valve unit 17.

[0075] The control valve 171 is a spool valve for switching the flow of the hydraulic oil in order to supply the hydraulic oil discharged from the left main pump 14L to the left traveling hydraulic motor 2ML and expel the hydraulic oil discharged from the left traveling hydraulic motor 2ML to the hydraulic oil tank.

[0076] The control valve 172 is a spool valve for switching the flow of the hydraulic oil in order to supply the hydraulic oil discharged from the right main pump 14R to the right traveling hydraulic motor 2MR and expel the hydraulic oil discharged from the right traveling hydraulic motor 2MR to the hydraulic oil tank.

[0077] The control valve 173 is a spool valve for switching the flow of the hydraulic oil in order to supply the hydraulic oil discharged from the left main pump 14L to the turning hydraulic motor 2A and expel the hydraulic oil discharged from the turning hydraulic motor 2A to the hydraulic oil tank.

[0078] The control valve 174 is a spool valve for switching the flow of the hydraulic oil in order to supply the hydraulic oil discharged from the right main pump 14R to the bucket cylinder 9 and expel the hydraulic oil in the bucket cylinder 9 to the hydraulic oil tank.

[0079] The control valve 175L is a spool valve for switching the flow of the hydraulic oil in order 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 for switching the flow of the hydraulic oil in order to supply the hydraulic oil discharged from the right main pump 14R to the boom cylinder 7 and expel the hydraulic oil in the boom cylinder 7 to the hydraulic oil tank.

[0080] The control valve 176L is a spool valve for switching the flow of the hydraulic oil in order to supply the hydraulic oil discharged from the left main pump 14L to the arm cylinder 8 and expel the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0081] The control valve 176R is a spool valve for switching the flow of the hydraulic oil in order to supply the hydraulic oil discharged from the right main pump 14R to the arm cylinder 8 and expel the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0082] The left parallel pipeline 42L is a hydraulic oil line parallel with the left center bypass pipeline 40L. When the flow of the hydraulic oil through the left center bypass pipeline 40L is restricted or blocked by any of the control valves 171, 173, or 175L, the left parallel pipeline 42L can supply the hydraulic oil to its downstream control valve(s). The right parallel pipeline 42R is a hydraulic oil line parallel with the right center bypass pipeline 40R. When the flow of the hydraulic oil through the right center bypass pipeline 40R is restricted or blocked by any of the control valves 172, 174, or 175R, the right parallel pipeline 42R can supply the hydraulic oil to its downstream control valve(s).

[0083] As described above, each of the boom cylinder 7, the arm cylinder 8 and the bucket cylinder 9 is provided with the cylinder pressure sensors.

[0084] Further, a left turning pressure sensor S10L and a right turning pressure sensor S10R are attached to the turning hydraulic motor 2A. The left turning pressure sensor S10L detects the pressure of the hydraulic oil at the left port of the turning hydraulic motor 2A. The right turning pressure sensor S10R detects the pressure of the hydraulic oil at the right port of the turning hydraulic motor 2A.

[0085] The regulators 13 include the left regulator 13L and the 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 in accordance with the discharge pressure of the left main pump 14L. Specifically, for example, the left regulator 13L decreases the discharge amount by adjusting the swash plate tilt angle of the left main pump 14L in accordance with an increase in the discharge pressure of the left main pump 14L. The same applies to the right regulator 13R. This is in order to prevent the absorbed power (absorbed horsepower) of the main pumps 14 represented by the product of the discharge pressure and the discharge amount from exceeding the output power (output horsepower) of the engine 11.

[0086] The operation device 26 includes a left operation lever 26L, a right operation lever 26R, and traveling levers 26D. The traveling levers 26D include a left traveling lever 26DL and a right traveling lever 26DR.

[0087] The operation sensors 29 include operation sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR.

[0088] The left operation lever 26L is used for turning operations and operations on the arm 5. When operated in the front-rear direction, the left operation lever 26L introduces a control pressure corresponding to the lever operation amount to the pilot ports of the control valves 176 by using the hydraulic oil discharged from the pilot pump 15. When operated in the left-right direction, the left operation lever 26L introduces a control pressure corresponding to the lever operation amount to the pilot ports of the control valve 173 by using the hydraulic oil discharged from the pilot pump 15.

[0089] The operation sensor 29LA detects the content of an operation performed by the operator on the left operation lever 26L in the front-rear direction and outputs the detected value to the controller 30.

[0090] The operation sensor 29LB detects the content of an operation performed by the operator on the left operation lever 26L in the left-right direction and outputs the detected value to the controller 30.

[0091] When the left operation lever 26L is operated in the arm closing direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29LA to introduce the hydraulic oil into the right pilot port of the control valve 176L and to introduce the hydraulic oil into the left pilot port of the control valve 176R. When the left operation lever 26L is operated in the arm opening direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29LA to introduce the hydraulic oil into the left pilot port of the control valve 176L and to introduce the hydraulic oil into the right pilot port of the control valve 176R.

[0092] When the left operation lever 26L is operated in the left turning direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29LB to introduce the hydraulic oil into the left pilot port of the control valve 173. When the left operation lever 26L is operated in the right turning direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29LB to introduce the hydraulic oil into the right pilot port of the control valve 173.

[0093] The left operation lever 26L is provided with a switch NS. In the present embodiment, the switch NS is a push button switch provided on the distal end of the left operation lever 26L. 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 may be provided at another position in the cabin 10.

[0094] The right operation lever 26R is used for operations on the boom 4 and operations on the bucket 6. When operated in the front-rear direction, the right operation lever 26R introduces a control pressure corresponding to the lever operation amount to the pilot ports of the control valves 175 by using the hydraulic oil discharged from the pilot pump 15. When operated in the left-right direction, the right operation lever 26R introduces a control pressure corresponding to the lever operation amount to the pilot ports of the control valve 174 by using the hydraulic oil discharged from the pilot pump 15.

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

[0096] The operation sensor 29RB detects the content of an operation performed by the operator on the right operation lever 26R in the left-right direction and outputs the detected value to the controller 30.

[0097] Specifically, when the right operation lever 26R is operated in the boom lowering direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29RA to introduce the hydraulic oil into the left pilot port of the control valve 175L and to introduce the hydraulic oil into the right pilot port of the control valve 175R. Further, when the right operation lever 26R is operated in the boom raising direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29RA to introduce the hydraulic oil into the right pilot port of the control valve 175L and to introduce the hydraulic oil into the left pilot port of the control valve 175R.

[0098] When the right operation lever 26R is operated in the bucket closing direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29RB to introduce the hydraulic oil into the right pilot port of the control valve 174. When the right operation lever 26R is operated in the bucket opening direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29RB to introduce the hydraulic oil into the left pilot port of the control valve 174.

[0099] The traveling lever 26D is used for operations on a crawler. Specifically, the left traveling lever 26DL is used for operations on the left crawler. The traveling lever 26D may be configured to interlock with the left traveling pedal.

[0100] The operation sensor 29DL detects the content of an operation performed by the operator on the left traveling lever 26DL in the front-rear direction and outputs the detected value to the controller 30.

[0101] When the left traveling lever 26DL is operated in the front-rear direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29DL to introduce a control pressure corresponding to the lever operation amount to a pilot port of the control valve 171 using the hydraulic oil discharged from the pilot pump 15.

[0102] The right traveling lever 26DR is used for operations on the right crawler. The right traveling lever 26DR may be configured to interlock with the right traveling pedal.

[0103] The operation sensor 29DR detects the content of an operation performed by the operator on the right traveling lever 26DR in the front-rear direction and outputs the detected value to the controller 30.

[0104] When the right traveling lever 26DR is operated in the front-rear direction, the controller 30 controls the proportional valve 31 in accordance with a signal from the operation sensor 29DR to introduce a control pressure corresponding to the lever operation amount to a pilot port of the control valve 172 using the hydraulic oil discharged from the pilot pump 15.

[0105] The discharge pressure sensors 28 include the discharge pressure sensor 28L and the 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.

[0106] The controller 30 receives outputs from the operation sensors 29, and outputs control commands to the regulators 13 as necessary to change the discharge amounts of the main pumps 14. The controller 30 also receives outputs from control pressure sensors 19 provided upstream of throttles (negative-control throttles) 18, and outputs control commands to the regulators 13 as necessary to change the discharge amounts of the main pumps 14. The throttles 18 includes a left throttle 18L and a right throttle 18R, and the control pressure sensors 19 include a left control pressure sensor 19L and a right control pressure sensor 19R.

[0107] The left center bypass pipeline 40L is provided with the left throttle 18L that is disposed between the control valve 176L located on the farthest downstream and the hydraulic oil tank. Therefore, the flow of the hydraulic oil discharged from the left main pump 14L is restricted by the left throttle 18. 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 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 in accordance with this control pressure. The controller 30 controls the discharge amount of the left main pump 14L to be lower as the control pressure is higher, and controls the discharge amount of the left main pump 14L to be higher as the control pressure is lower. The discharge amount of the right main pump 14R is controlled in the same manner.

[0108] Specifically, as shown in FIG. 3, in a standby state in which none of the hydraulic actuators of the excavator 100 are operated, the hydraulic oil discharged from the left main pump 14L passes through the left center bypass pipeline 40L and reaches the left throttle 18L. The flow of the hydraulic oil discharged from the left main pump 14L increases the control pressure to be generated upstream of the left throttle 18L. As a result, the controller 30 reduces the discharge amount of the left main pump 14L to a tolerable minimum discharge amount to restrict a pressure loss (pumping loss) that might occur when the discharged hydraulic oil passes through the left center bypass pipeline 40L. On the other hand, when any of the hydraulic actuators is operated, the hydraulic oil discharged from the left main pump 14L flows into the operation-target hydraulic actuator via the control valve corresponding to the operation-target hydraulic actuator. This reduces the amount by which the flow of the hydraulic oil discharged from the left main pump 14L reaches the left throttle 18L or completely eliminates such a flow, to thereby reduce the control pressure to be generated upstream of the left throttle 18L. As a result, the controller 30 increases the discharge amount of the left main pump 14L, circulates the hydraulic oil sufficiently to the operation-target hydraulic actuator, to ensure that the operation-target hydraulic actuator is driven securely. The controller 30 controls the discharge amount of the right main pump 14R in the same manner.

[0109] With the above-described configuration, the hydraulic system of FIG. 3 can save wasteful energy consumption by the main pumps 14 in the standby state. The wasteful energy consumption includes pumping loss generated through the center bypass pipelines 40 by the hydraulic oil discharged from the main pumps 14. In addition, when actuating any hydraulic actuator, the hydraulic system of FIG. 3 can reliably supply the necessary and sufficient amount of hydraulic oil to the operation-target hydraulic actuator from the main pumps 14.

[0110] That is, the controller 30 controls each regulator 13 such that the discharge amount will be the smaller of: a first discharge amount calculated to not allow the absorbed power (absorbed horsepower) of the corresponding main pump 14, which is indicated by the product of the discharge pressure and the discharge amount, to exceed the output power (output horsepower) of the engine 11; and a second discharge amount calculated based on the control pressure detected by the corresponding control pressure sensor 19.Description of Functions of Machine Control Function Unit

[0111] The machine control function unit 50 according to the present embodiment performs control on the movements of the boom 4 and the bucket 6 upon receiving an operation on the arm 5 from the operator, such that the tip of a claw of the bucket 6 is along a target work surface along with the movement of the arm 5.

[0112] FIG. 4 is a conceptual diagram showing an example of the target work surface to be worked by the excavator 100 according to the present embodiment. In the example shown in FIG. 4, the target work surface to be worked by the excavator 100 includes a first target work surface 1401 and a second target work surface 1402. The first target work surface 1401 and the second target work surface 1402 intersect each other at a predetermined angle at a boundary 1403. In this situation, it is difficult for the excavator 100 to move the bucket 6 along the first target work surface 1401 and the second target work surface 1402.

[0113] FIG. 5 is a diagram showing a movement locus of the bucket obtained when a conventional machine control function is executed for the target work surface shown in FIG. 4. In the example shown in FIG. 5, a sediment 1501 is formed.

[0114] In the example shown in FIG. 5, when the bucket of the conventional excavator moves from a first position 6A to the first target work surface 1401 and to the second target work surface 1402 in this order, the bucket moves while forming a locus 1502. Therefore, it is difficult to form a sharp edge at the boundary 1403 between the first target work surface 1401 and the second target work surface 1402.

[0115] Generally, when an excavator works a slope, it often works the first target work surface 1401 and the second target work surface 1402 separately. For example, after work on the first target work surface 1401 is completed, work on the second target work surface 1402 is performed.

[0116] When starting work on the second target work surface 1402 using the machine control function, the conventional excavator can move the tip of a claw of the bucket along the second target work surface 1402 by aligning the tip of a claw of the bucket with the boundary 1403. However, if the bucket is located on the back of the boundary 1403 (on the first target work surface 1401 side) even slightly, the tip of a claw of the bucket is controlled to be along the first target work surface 1401 by the machine control function. Therefore, when the bucket is located on the back of the boundary 1403 (on the first target work surface 1401 side) even slightly, use of the conventional machine control function results in, for example, the bucket being controlled to move to a second position 6B.

[0117] When the second target work surface 1402 is worked from the second position 6B, control is performed such that movement is performed along the first target work surface 1401 and then along the second target work surface 1402, which might make it impossible to form an edge appropriately at the boundary 1403 between the first target work surface 1401 and the second target work surface 1402. When using the machine control function in such a situation in which a plurality of target work surfaces intersect, there is a problem that the operator has difficulty with aligning the tip of a claw of the bucket or the like in place in a manner that desired work on the target work surface can be performed.

[0118] Therefore, the machine control function unit 50 according to the present embodiment performs control to cause the bucket 6 to move along a region extended from a target work surface.

[0119] FIG. 6 is a diagram showing a guide surface set under the control from the machine control function unit 50 according to the present embodiment, and the movement of the bucket 6 along the guide surface. In the example shown in FIG. 6, when receiving an operation to select the second target work surface 1402 as a work target from the operator, the machine control function unit 50 sets a region extended from the second target work surface 1402 as a virtual guide surface 1601 in a reference coordinate system in which the excavator 100 exists. The guide surface 1601 is a surface obtained by extending the second target work surface 1402 in the vertical direction. When receiving an operation to start the machine control function from the operator, the machine control function unit 50 controls the movement of one or more of the bucket 6 or the boom 4 to move the tip of a claw of the bucket 6 to a position at which the tip of a claw of the bucket 6 contacts the guide surface 1601 (for example, a third position 6C).

[0120] The reference coordinate system is, for example, the world geodetic system. The world geodetic system is a three-dimensional orthogonal XYZ coordinate system having the origin on the center of gravity of the earth, the X-axis in the direction toward the intersection of the Greenwich meridian and the equator, the Y-axis in the direction toward the 90 degrees east longitude, and the Z-axis is in the direction toward the North Pole. For example, by defining a desired point on the work site as the reference point, the operator may set a target work surface in accordance with the relative positional relationship with the reference point via an information input device.

[0121] The guide surface 1601 is a plane extended from the second target work surface 1402. Therefore, when receiving a closing operation on the arm 5 from the operator in a situation in which the bucket 6 exists at a position in contact with the guide surface 1601 (for example, the third position 6C), the machine control function unit 50 performs control to move the tip of a claw of the bucket 6 along a locus 1602. Thus, the tip of a claw of the bucket 6 can move while maintaining a state of being in contact with the second target work surface 1402 from the boundary 1403.

[0122] Therefore, even without performing positioning of the tip of a claw of the bucket 6 to align with the work start position (for example, the boundary 1403) for the second target work surface 1402, the operator can easily move the bucket 6 to a position at which the second target work surface 1402 can be worked. Further, since the tip of a claw of the bucket 6 can be maintained in contact with the second target work surface 1402 from the end of the second target work surface 1402, an edge can be appropriately formed at the boundary 1403 between the first target work surface 1401 and the second target work surface 1402. Therefore, the work accuracy can be improved.Configuration of Machine Control Function Unit

[0123] Referring back to FIG. 2, the machine control function unit 50 will be described. The machine control function unit 50 executes, for example, a machine guidance function for moving the boom 4, the arm 5, and the bucket 6 such that the tip of a claw of the bucket 6 moves along a target work surface. For example, data on the target work surface is previously stored in a storage medium 47.

[0124] The storage medium 47 is a nonvolatile readable / writable storage medium. The storage medium 47 stores target work surface information (an example of reference surface information) 47A representing the shape of the target work surface to result from work by the excavator 100. The work includes, for example, excavation work, soil compaction work, land preparation work, or the like.

[0125] The target work surface information 47A is stored in the storage medium 47, for example, based on input of settings performed by the operator via an information input device (not shown), or by being downloaded from outside (for example, a predetermined management server). The target work surface information 47A is expressed based on, for example, the reference coordinate system described above.

[0126] The machine control function unit 50 acquires information from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine body inclinometer S4, the turning angle sensor S5, the image capture devices S6, the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B, the arm rod pressure sensor S8R and the arm bottom pressure sensor S8B, the bucket rod pressure sensor S9R and the bucket bottom pressure sensor S9B, the positioning device PS, the operation sensors 29, the communication device T1, the input device 62, and the like. Then, based on the acquired information, the machine control function unit 50 performs, for example, calculation of the distance between the bucket 6 and the target work surface, automatic control on the movements of the attachments such that the back surface of, or the tip of a claw of, the bucket 6 coincides with the target work surface, and the like.

[0127] A configuration in which the machine control function unit 50 performs control on land preparation work will be described. The machine control function unit 50 includes, as a machine control function, a display control unit 501, a reception unit 502, a setting unit 503, an acquisition unit 504, and an automatic control unit 505 as a detailed functional configuration for performing land preparation work.

[0128] The display control unit 501 displays image information on the display device 60. For example, the display control unit 501 displays, on the display device 60, image information representing the shape of the target work surface represented by the target work surface information (an example of the reference surface information) 47A in the reference coordinate system from a desired perspective.

[0129] The reception unit 502 receives information that is input via the input device 62. For example, when a plurality of target work surfaces are displayed on the display device 60, the reception unit 502 receives, via the input device 62, selection of the target work surface to be worked next.

[0130] When the selection of the target work surface is received, the setting unit 503 sets a virtual guide surface that is extended from the target work surface in the reference coordinate system. The guide surface is a virtual surface generated in the machine control function unit 50 as a reference for the machine control function unit 50 to guide a work part of the bucket 6 (for example, the tip of a claw of the back surface). The guide surface may have any shape that can guide the work part of the bucket 6 (for example, the tip of a claw or the back surface), and may be, for example, a flat surface or a curved surface. Although the present embodiment describes an example of setting a guide surface as an example of the region extended from the target work surface, the data to be set is not limited to a guide surface, and may be, for example, a guide line and the like.

[0131] When the work part of the bucket 6 is the tip of a claw of the bucket 6, the control target in the work part of the bucket 6 (hereinafter, simply referred to as “the control target in the bucket 6”) may be set at a point on a curved surface or a flat surface constituting the tip of a specific one claw of a plurality of claws of the bucket 6. When the work part of the bucket 6 is the back surface of the bucket 6, for example, the control target in the bucket 6 may include a flat surface or a curved surface constituting the back surface of the bucket 6, a line segment defined in the flat surface or the curved surface, a point defined in the flat surface or the curved surface, and the like.

[0132] The display control unit 501 may display a guide surface set by the setting unit 503. Next, an operation procedure until a guide surface is set will be described.

[0133] FIG. 7 is a diagram showing transition of screen views displayed until a guide surface is set by the machine control function unit 50 according to the present embodiment.

[0134] As shown in the first screen view 1701 in FIG. 7, the display control unit 501 displays the shape of the target work surface represented by the target work surface information 47A on the display device 60. Although the first screen view 1701 shows a case in which a first target work surface 1711 and a second target work surface 1712 are viewed from a side for the purpose of explanation, the present invention is not limited to this screen view example. For example, a form of the target work surface when viewed from inside the cabin 10 of the excavator 100 may be displayed on the screen.

[0135] The present embodiment is an example in which the input device 62 is the touch panel provided on the display region of the display device 60. Thus, the reception unit 502 can receive selection of a region displayed on the screen.

[0136] Then, the reception unit 502 receives selection of the surface to be worked next by the excavator 100 from the first target work surface 1711 and the second target work surface 1712. In the example shown in FIG. 7, the reception unit 502 receives the selection of the second target work surface 1712. In the present embodiment, when there are a plurality of target work surfaces, selection of a target surface to be worked is received from among the plurality of target work surfaces. Thus, when there are a plurality of target work surfaces, the machine control function unit 50 can identify the target work surface for which to set a guide surface.

[0137] The second screen view 1702 is an example of a screen view displayed by the display control unit 501 after the selection of the second target work surface 1712 is received. As shown in the second screen view 1702, the display control unit 501 displays the second target work surface 1721, the selection of which is received, in a different display style. For example, the surface color of the second target work surface 1721 may be changed to become different from other surfaces, or the contour line of the second target work surface 1721 may be changed to become thicker.

[0138] Furthermore, a guide button 1722 is displayed on the second screen view 1702. The guide button 1722 is a button for switching whether or not to set a guide surface.

[0139] The reception unit 502 receives depression of the guide button 1722. Thus, the setting unit 503 sets a guide surface by extending the selected second target work surface 1721. The target work surface information 47A includes coordinate information of the second target work surface 1721 in the reference coordinate system. Therefore, the setting unit 503 can calculate and set the coordinate information of the guide surface in the reference coordinate system by referring to the target work surface information 47A.

[0140] Specifically, the setting unit 503 sets a guide surface by extending the second target work surface 1721 in a direction in which the bucket 6 can move. The extending length may be any length, and may be, for example, 1 m. When it is desired that the bucket 6 is moved along the second target work surface 1721, setting the guide surface makes it possible to guide the bucket 6 to move in the direction desired by the operator. Therefore, the operation load when moving the bucket 6 can be reduced. Further, although the guide surface according to the present embodiment is set to be substantially parallel with the target work surface, the method for setting the guide surface is not limited to the method of setting it to be substantially parallel. As long as the target work surface can be worked from an end, the guide surface may be inclined from the target work surface.

[0141] The third screen view 1703 is an example of a screen view displayed by the display control unit 501 after the depression of the guide button 1722 is received. As shown in the third screen view 1703, the display control unit 501 displays the depressed guide button 1731 in a color different from the color before the depression.

[0142] Further, the display control unit 501 displays image information representing the guide surface 1732 extended from an end 1733 of the second target work surface 1721 when viewed from a side, together with the first target work surface 1711 and the second target work surface 1721 on the display device 60. By displaying the guide surface 1732, the operator can recognize how the bucket 6 moves when the machine control function is executed. Therefore, the operation load on the operator can be reduced.

[0143] Referring back to FIG. 2, the acquisition unit 504 acquires detection information indicating detection results acquired by various sensors in the excavator 100 from the sensors. For example, the acquisition unit 504 acquires detection information from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine body inclinometer S4, the turning angle sensor S5, the image capture devices S6, the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B, the arm rod pressure sensor S8R and the arm bottom pressure sensor S8B, the bucket rod pressure sensor S9R and the bucket bottom pressure sensor S9B, and the positioning device PS.

[0144] Further, the acquisition unit 504 acquires operation information indicating the content of an operation on the operation device 26 from the operation sensors 29, and acquires a signal corresponding to an operation input from the input device 62. The acquisition unit 504 also acquires information received from an external device via the communication device T1. For example, when the excavator 100 is remotely controlled, the acquisition unit 504 may acquire an operation signal received from an external device via the communication device T1.

[0145] The automatic control unit 505 automatically assists manual operations on the excavator 100 performed by the operator via the operation device 26, by automatically moving the actuators. Specifically, the automatic control unit 505 can individually and automatically adjust the pilot pressures to be applied to the control valves (specifically, the control valve 173, the control valves 175L and 175R, and the control valve 174) corresponding to a plurality of hydraulic actuators (specifically, the turning hydraulic motor 2A, the boom cylinder 7, and the bucket cylinder 9). Thus, the automatic control unit 505 can automatically move the respective hydraulic actuators. The control related to the machine control function executed by the automatic control unit 505 may be performed, for example, under depression of a predetermined switch included in the input device 62. The predetermined switch is, for example, a Machine Control switch (hereinafter, “MC switch”), which may be provided in the form of a push button switch on the tip of an operation lever of the operation device 26 (for example, the left operation lever 26L used for operating the arm 5), or may be separately provided near an operation lever of the operation device 26. The following description will proceed on the assumption that the machine control function unit 50 performs control under depression of the predetermined switch.

[0146] For example, under depression of the predetermined switch or the like, the automatic control unit 505 controls the movement of the arm 5 in accordance with an operation for closing or opening the arm 5 received from the operation sensor 29, and controls the boom angle and the bucket angle (examples of attachment angles) based on the detection information from the boom angle sensor S1 and the bucket angle sensor S3 such that the work part of the bucket 6 (for example, the tip of a claw or the back surface) contacts the target work surface or the guide surface.

[0147] As a specific control on the movement, under depression of the predetermined switch or the like, the automatic control unit 505 automatically extends or contracts the boom cylinder 7 and the bucket cylinder 9 in accordance with the movement of the arm cylinder 8 such that the boom angle and the bucket angle will be angles at which the positions of the target work surface or the guide surface and of the work part of the bucket 6 substantially coincide. The movement of the arm cylinder 8 is controlled by the automatic control unit 505 to match the manual operation for opening or closing the arm 5 performed by the operator.

[0148] Thus, under depression of the predetermined switch or the like, when the work part of the bucket 6 (for example, the tip of a claw or the back surface) is apart from the target work surface or the guide surface, the automatic control unit 505 controls the boom cylinder 7 and the bucket cylinder 9 such that the work part of the bucket 6 (for example, the tip of a claw or the back surface) contacts the target work surface or the guide surface.

[0149] When a manual operation for opening or closing the arm 5 is started by the operator, the automatic control unit 505 controls the boom cylinder 7 and the bucket cylinder 9 such that the work part of the bucket 6 (for example, the tip of a claw or the back surface) is kept in contact with the target work surface or the guide surface along with the closing or opening movement of the arm 5.

[0150] Therefore, as shown in FIG. 6, when the bucket 6 is located on the back of the boundary 1403 (on the first target work surface 1401 side), the automatic control unit 505 performs control to move the boom 4 and the bucket 6 such that the tip of a claw of the bucket 6 contacts the guide surface 1601, and then to move the tip of a claw of the bucket 6 along the guide surface 1601 in accordance with an operation from the operator. Thus, such a movement of the tip of a claw of the bucket 6 as to come into contact with the first target work surface 1401 can be inhibited. Therefore, the tip of a claw of the bucket 6 can move from the boundary 1403 along the second target work surface 1402.

[0151] The setting unit 503 may cancel the setting of the guide surface at any timing; for example, the setting unit 503 may cancel the setting of the guide surface after the bucket 6 has finished moving along the guide surface under the movement control from the automatic control unit 505. Furthermore, the setting unit 503 may cancel the setting of the guide surface when the reception unit 502 receives another depression of the guide button.

[0152] In the above example, the setting unit 503 sets the guide surface for guiding the starting position of the work to be performed by the bucket 6. However, the present embodiment is not limited to the setting of the guide surface for guiding the starting position of the work.

[0153] FIG. 8 is a diagram showing a guide surface set under the control from the machine control function unit 50 according to the present embodiment, and the movement of the bucket 6 along the guide surface. In the example shown in FIG. 8, which is an example of performing work on a sediment shape 1805, a first target work surface 1801 and a second target work surface 1802 having the shapes after being worked are shown.

[0154] When an operation for selecting the first target work surface 1801 as a work target is received from the operator, the setting unit 503 sets a virtual guide surface 1803 extended from the first target work surface 1801. The guide surface 1803 is a surface extended from an end 1804 of the first target work surface 1801 in a direction in which the bucket 6 can move.

[0155] When an operation for closing the arm 5 is received from the operator, the machine control function unit 50 realizes a movement along a locus 1806 by controlling the movement of one or more of the bucket 6 or the boom 4. That is, the tip of a claw of the bucket 6 moves along the guide surface 1803 after moving along the first target work surface 1801. Therefore, the first target work surface 1801 can be worked such that the tip of a claw of the bucket 6 is along the first target work surface 1801 up to the end 1804. Therefore, the work accuracy can be improved.

[0156] In the present embodiment, a case where two target work surfaces intersect each other has been described. However, the present embodiment is not limited to the case where two target work surfaces intersect each other, and can be applied to a case where three or more target work surfaces are combined.

[0157] FIG. 9 shows a guide surface set under the control from the machine control function unit 50 according to the present embodiment. In the example shown in FIG. 9, which is an example of performing work on a sediment shape 1904, a first target work surface 1901, a second target work surface 1902, and a third target work surface 1903 are shown as having shapes after being worked.

[0158] When an operation for selecting the second target work surface 1902 as a work target is received from the operator, the setting unit 503 sets virtual guide surfaces 1905A and 1905B that are extended from the second target work surface 1902. The guide surface 1905A is a surface extended from an end 1906 of the second target work surface 1902 in a direction in which the bucket 6 can move. The guide surface 1905B is a surface extended from an end 1907 of the second target work surface 1902 in a direction in which the bucket 6 can move. Thus, the bucket 6 is moved over the guide surface 1905A, the second target work surface 1902, and the guide surface 1905B in this order in the state in which the tip of a claw of the bucket 6 is in contact with the respective surfaces. Thus, the second target work surface 1902 can be appropriately worked between both ends, thereby improving work accuracy.

[0159] Next, a processing procedure performed by the machine control function unit 50 according to the present embodiment will be described. FIG. 10 is a flowchart showing a processing procedure performed by the machine control function unit 50 according to the present embodiment.

[0160] First, the display control unit 501 displays one or a plurality of target work surfaces included in the target work surface information 47A as viewed from a predetermined perspective in the reference coordinate system (S2001).

[0161] Then, the reception unit 502 determines whether or not selection of a target work surface displayed has been received (S2002). When it is determined that no selection has been received (S2002: NO), the processing ends.

[0162] On the other hand, when the reception unit 502 determines that selection of a displayed target work surface has been received (S2002: YES), the display control unit 501 changes the display style of the selected target work surface, and displays a guide button (S2003).

[0163] Thereafter, the reception unit 502 determines whether depression of the displayed guide button has been received (S2004). When it is determined that no depression has been received (S2004: NO), the processing ends.

[0164] On the other hand, when the reception unit 502 determines that depression of the displayed guide button has been received (S2004: YES), the setting unit 503 sets a guide surface extended from the selected target work surface (S2005).

[0165] Then, the display control unit 501 displays the set guide surface (S2006).

[0166] The reception unit 502 determines whether or not the depression of the MC switch has been received (S2007). When it is determined that no depression of the MC switch has been received (NO in step S2007), the reception unit 502 waits until depression is received.

[0167] On the other hand, when the reception unit 502 determines that depression of the MC switch has been received (YES in step S2007), the automatic control unit 505 starts movement control such that the tip of a claw of the bucket 6 contacts the guide surface or the target work surface (S2008).

[0168] Thereafter, the automatic control unit 505 performs movement control such that the tip of a claw of the bucket 6 moves along the guide surface or the target work surface in accordance with an operation for closing or opening the arm 5 (S2009).

[0169] By performing control on the movements of the bucket 6 and the boom 4 such that the tip of a claw of the bucket 6 is along the guide surface set to be extended from the target work surface, the machine control function unit 50 according to the present embodiment can cause the tip of a claw of the bucket 6 to work the target work surface up to the end, thereby improving accuracy.Modification of First Embodiment

[0170] In the above-described embodiment, a case where a guide surface is set in response to selection of a target work surface to be worked has been described. However, the above-described embodiment shows one example of guide surface setting, and a guide surface may be set in any other manner. Therefore, an example of automatically setting a guide surface will be described as a modification.

[0171] FIG. 11 is an explanatory diagram showing a control procedure performed by the machine control function unit 50 according to a modification of the first embodiment.

[0172] In FIG. 11, a case of performing work on sediment 2103 along a first target work surface 2101 first and then along a second target work surface 2102 is assumed.

[0173] In the first step 2151, the setting unit 503 sets a guide surface 2111 that is extended from the first target work surface 2101. As a method for setting the guide surface 2111, for example, based on the position of the bucket 6, the guide surface 2111 may be set for the first target work surface 2101 that is closer to the bucket 6 of the plurality of target work surfaces. Then, the automatic control unit 505 performs movement control such that the tip of a claw of the bucket 6 moves along the first target work surface 2101 and the guide surface 2111.

[0174] In the second step 2152, the setting unit 503 cancels the setting of the guide surface 2111 as the tip of a claw of the bucket 6 has reached the end of the guide surface 2111.

[0175] In the third step 2153, the setting unit 503 estimates that the second target work surface 2102 is the next work target based on the position of the tip of a claw of the bucket 6 (that has reached the end of the guide surface 2111), and sets a guide surface 2131 that is extended from the second target work surface 2102 estimated to be the next work target.

[0176] In the fourth step 2154, the automatic control unit 505 performs control on the movements of the bucket 6 and the boom 4 such that the tip of a claw of the bucket 6 contacts the guide surface 2131.

[0177] After the tip of a claw of the bucket 6 contacts the guide surface 2131, the automatic control unit 505 performs movement control such that the tip of a claw of the bucket 6 moves along the second target work surface 2102 after moving along the guide surface, in accordance with an operation for closing or opening the arm 5.

[0178] In this modification, the setting unit 503 performs setting of a guide surface and canceling of the setting of the guide surface based on the position of the tip of a claw of the bucket 6. Thus, because of the reduction of the operation related to the guide surface, the operability can be improved for the operator.Second Embodiment

[0179] In the above-described embodiment, the case where the operator performs operations in the cabin 10 has been described. However, the above-described embodiment is not limited to the case where the operator performs operations in the cabin 10. For example, a remote control system of the excavator 100 may perform the same processing as in the above-described embodiment. Therefore, in the second embodiment, a case where a remote control system of the excavator performs setting of a guide surface will be described.

[0180] Thus, an outline of a remote control system SYS according to the second embodiment will be described with reference to FIG. 12. FIG. 12 is a schematic diagram showing an example of the remote control system SYS according to the second embodiment.

[0181] As shown in FIG. 12, the remote control system SYS according to the second embodiment includes an excavator 100 and a remote control chamber RC. The excavator 100 according to the present embodiment has the same configuration as that in the above-described embodiment.

[0182] The excavator 100 and the remote control chamber RC are connected via a communication line NT such that data can be transmitted and received.

[0183] The excavator 100 can perform wireless communication by using the communication device T1. The excavator 100 can exchange data with a device connected to the communication line NT (for example, the remote control chamber RC).

[0184] The excavator 100 can transmit information related to the work site to the remote control chamber RC. Thus, the remote control chamber RC can confirm the work site in accordance with the information from the excavator 100. In the present embodiment, the device for measuring the work site is not limited to the excavator 100, but may be a device of any other mode, such as a drone flying above the work site, a fixed-point camera, an image capture device available for use by a user, and the like.

[0185] For example, the excavator 100 is provided with the image capture devices S6. The excavator 100 transmits a captured image showing a result of image capture at the work site by the image capture devices S6 to the remote control chamber RC.

[0186] One or a plurality of excavators 100 may be included in the remote control system SYS. Thus, the remote control system SYS can provide information related to the work site to the remote control chamber RC through the plurality of excavators 100.Configuration Example of Remote Control Chamber

[0187] The remote control chamber RC includes a communication device T2, a remote controller R30, an operation device R26, an operation sensor R29, an input device R62, and display devices D1 and D2. The remote control chamber RC is equipped with a operation seat DS in which an operator OP who remotely controls the excavator 100 is seated.

[0188] The communication device T2 is configured to control communication with the communication device T1 attached to the excavator 100.

[0189] The remote controller (an example of a remote control unit) R30 is a calculation unit that executes various calculations. In the present embodiment, the remote controller R30 is composed of a microcomputer including a CPU and a memory. Various functions of the remote controller R30 are implemented by the CPU executing a program stored in the memory.

[0190] The display device D1 displays a screen view that is based on information transmitted from the excavator 100 in order for the operator OP in the remote control chamber RC to visually confirm the surrounding of the excavator 100. The display device D1 enables the operator to confirm the situation at the work site including the surrounding of the excavator 100 even though the operator is in the remote control chamber RC.

[0191] The display device D2 is provided at a location at which the display device D2 is easily visible from the operator OP in the remote control chamber RC, and displays various information images under control from the controller 30. For example, when the communication device T2 receives the target work surface information 47A from the excavator, it may display the shape of the target work surface in the reference coordinate system.

[0192] In this example, the input device R62 is a touch panel provided in the display region of the display device D2. This makes it possible to select a target work surface as in the above-described embodiment. Information related to the target work surface, selection of which is received by the input device R62, is transmitted to the excavator 100 via the communication device T2.

[0193] The setting unit 503 of the machine control function unit 50 sets the guide surface based on the received information. Thereafter, the machine control function unit 50 transmits information related to the guide surface to the remote control chamber RC via the communication device T1.

[0194] The display device D2 displays the received guide surface. Thus, the operator OP in the remote control chamber RC can recognize that the guide surface for guiding the tip of a claw of the bucket 6 has been set. Then, the remote controller (an example of the remote control unit) R30 transmits to the excavator 100, via the communication device T2, an operation signal indicating an operation for opening or closing the arm 5, received via the operation device R26.

[0195] Based on the received operation signal, the machine control function unit 50 of the excavator 100 controls the movements of the bucket 6 and the boom 4 to move the tip of a claw of the bucket along the guide surface. Thus, remote control on the excavator 100 can be realized from the remote control chamber RC. The subsequent control is the same as in the above-described embodiment.Effect

[0196] According to the above-described embodiments and modification, by performing control to move the bucket 6 along a guide surface that is extended from a target work surface selected by the operator, from among a plurality of target work surfaces represented by the target work surface information 47A, it is possible to avoid a situation in which the bucket 6 might come into contact with any other target work surface, and thereby to improve the operability.

[0197] Furthermore, by moving the tip of a claw of the bucket 6 along the guide surface, it is possible to work, the selected target work surface from an end of the target work surface. Therefore, the work accuracy can be improved.

[0198] The above-described embodiments and modification have been described concerning the case where the work machine is an excavator. However, the above-described embodiments and modification are not limited to an excavator, and any work machine that includes an attachment and a work tool may be used.

[0199] The embodiments of the work machine and the remote control system for the work machine according to the present invention have been described above. However, the present invention is not limited to the above embodiments and the like. Various changes, modifications, substitutions, additions, deletions, and combinations are applicable within the scope of description in the claims. Naturally, they are also included in the technical scope of the present invention.

Claims

1. A work machine, comprising:a lower traveling body;an upper turning body turnably mounted on the lower traveling body;an attachment attached to the upper turning body;a work tool provided on a distal end of the attachment;a storage configured to store reference surface information representing a shape of a surface after being worked; anda controller including a processor and a memory and configured to perform control to move the work tool along a region that is extended from the surface represented by the reference surface information.

2. The work machine according to claim 1,wherein when selection of the surface represented by the reference surface information is received, the controller is configured to set, as a virtual guide surface, the region that is extended from the surface, the selection of which is received, in a coordinate system in which the work machine exists, and to perform control to move the work tool along the guide surface.

3. The work machine according to claim 2,wherein the guide surface is extended from the surface represented by the reference surface information in a direction in which the work tool can move.

4. The work machine according to claim 2,wherein the controller is configured to display on a display device, image information representing the surface represented by the reference surface information and the guide surface, as viewed from a predetermined perspective in the coordinate system.

5. The work machine according to claim 2,wherein the controller is configured to cancel setting of the guide surface after the work tool moves along the guide surface.

6. The work machine according to claim 1,wherein the controller is configured to set, as a virtual guide surface, a region extended from a surface that is estimated to be a work target based on a position of the work tool, and to perform control to move the work tool along the virtual guide surface.

7. A remote control system for a work machine, the remote control system comprising:a controller for remote control, including a processor, a memory, an operation device, and a first communication device configured to transmit a signal received by the operation device; anda work machine including a lower traveling body, an upper turning body turnably mounted on the lower traveling body, an attachment attached to the upper turning body, a work tool provided on a distal end of the attachment, a storage configured to store reference surface information representing a shape of a surface after being worked, a second communication device configured to receive the signal, and a controller including a processor and a memory and configured to perform, based on an operation indicated by the signal, control to move the work tool along a region that is extended from the surface represented by the reference surface information.

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