EXCAVATOR AND EXCAVATOR OPERATION SYSTEM

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority to Japanese Patent Application No. 2024-073441, filed on Apr. 30, 2024, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to an excavator and an excavator operation system.

2. Description of Related Art

Hydraulic excavators with a machine control function for the drive mechanism have been known in the related art. The machine control function for the hydraulic excavator described in the related art includes automatic work machine stop control, automatic ground leveling support control, slewing alignment control, traveling alignment control, automatic operation control, and the like.

SUMMARY

According to an aspect of the present disclosure, an excavator is provided. The excavator includes:

• • a lower traveling body;
  • an upper slewing body slewably provided on the lower traveling body; and
  • an attachment provided on the upper slewing body,
  • wherein the attachment includes
    • a bucket rotatable around a first axis along a width direction, and
    • a rotator configured to rotate the bucket around a second axis along a longitudinal direction to cause earth and sand to overflow to one side of the bucket during excavation of a construction surface by the bucket.

According to another aspect of the present disclosure, an excavator operation system is provided. The excavator operation system includes:

• • an excavator including a lower traveling body, an upper slewing body slewably provided on the lower traveling body, an attachment provided on the upper slewing body, and a communication device provided on the upper slewing body;
  • a remote operation device configured to detect an operation amount of the excavator by a remote operator; and
  • a remote communication device configured to transmit the operation amount detected by the remote operation device to the communication device,
  • wherein the attachment includes
    • a bucket rotatable around a first axis along a width direction, and
    • a rotator configured to rotate the bucket around a second axis along a longitudinal direction to cause earth and sand to overflow to one side of the bucket during excavation of a construction surface by the bucket.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view illustrating an excavator according to an embodiment of the present disclosure.

FIG. 2 is a block diagram schematically illustrating a configuration of the excavator illustrated in FIG. 1.

FIG. 3 is a functional block diagram illustrating a controller of the excavator illustrated in FIG. 2.

FIG. 4 is a flowchart of a process by the controller illustrated in FIG. 3.

FIG. 5 is a schematic plan view illustrating excavation work by the excavator illustrated in FIG. 1.

FIG. 6 is a schematic plan view of excavation work by an excavator according to a comparative example.

FIG. 7 is a schematic diagram illustrating an excavator operation system according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

It is desirable that when earth and sand overflows on both sides of a bucket when excavating a construction surface by an excavator, a width of overlapping a range excavated by the next excavation work after finishing one excavation work with a range excavated by the previous excavation work increases, and work efficiency is reduced.

The present disclosure provides an excavator and an excavator operation system capable of improving work efficiency.

According to the above aspects of the present disclosure, it is possible to provide an excavator and an excavator operation system capable of improving work efficiency.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The embodiments described below are merely examples and do not limit the invention. All features and combinations thereof in the embodiments of the present disclosure are not necessarily essential to the invention. In the drawings, the same or corresponding elements are denoted by the same or corresponding reference numerals, and redundant description thereof may be omitted.

Embodiment

First, an excavator according to an embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view illustrating an excavator according to the embodiment of the present disclosure. FIG. 2 is a block diagram schematically illustrating a configuration of the excavator 100 illustrated in FIG. 1. In FIG. 2, the mechanical power transmission system, the hydraulic fluid line, the pilot line, and the electric control system are indicated by a double line, a thick solid line, a thick broken line, and a dotted line, respectively.

The excavator 100 according to the embodiment of the present disclosure includes a lower traveling body 1, an upper slewing body 3 slewably provided on the lower traveling body 1, and an attachment AT provided on the upper slewing body 3. The attachment AT includes a bucket 6 rotatable around a first axis A1 along a width direction Dw, and a rotator R. As will be described in detail later, the excavator 100 according to the present embodiment is characterized in that the bucket 6 is rotated around a second axis A2 along a longitudinal direction D1 by the rotator R to cause the earth and sand to overflow to one side of the bucket 6 when the bucket 6 excavates the construction surface. Hereinafter, the configuration of each part of the excavator 100 according to the present embodiment will be described in detail.

The lower traveling body 1 includes, for example, a pair of left and right crawlers 1C. In particular, the crawlers 1C include a left crawler 1CL and a right crawler 1CR. The left crawler 1CL is driven by a left traveling hydraulic motor 2ML, and the right crawler 1CR is driven by a right traveling hydraulic motor 2MR. The left traveling hydraulic motor 2ML is a traveling drive part that drives the left crawler 1CL as a driven part, and can rotate the left crawler 1CL. The right traveling hydraulic motor 2MR is a traveling drive part that drives the right crawler 1CR as a driven part, and can rotate the right crawler 1CR. The traveling drive part may be an electric motor.

The upper slewing body 3 is mounted on the lower traveling body 1 via a slewing mechanism 2, and is thereby slewably provided on the lower traveling body 1. The attachment AT for performing various operations is attached to the center of the front portion of the upper slewing body 3, and an operation cab 10 in which an operator of the excavator 100 sits is provided on the left side of the front portion of the upper slewing body 3. The operation cab 10 is also called a cabin or a cab. However, when the excavator 100 is remotely operated or when the excavator 100 is operated by fully automatic driving, the operation cab 10 may be omitted.

The front side of the excavator 100 (upper slewing body 3) corresponds to a side on which the attachment AT is attached to the upper slewing body 3 when the excavator 100 is viewed from directly above along the slewing axis of the upper slewing body 3. The left side, the right side, and the rear side of the excavator 100 (upper slewing body 3) correspond to the left side, the right side, and the rear side, respectively, as viewed from the operator seated on the operator's seat in the operation cab 10.

The attachment AT includes, for example, an arm 5 and a boom 4 in addition to the bucket 6 and the rotator R described above. The arm 5 is configured to support the bucket 6 via, for example, an arm top pin provided at the tip of the arm 5 so that the bucket 6 is rotatable around a first axis A1 parallel to the width direction Dw. The boom 4 is configured to support the arm 5 via a boom top pin provided at the tip of the boom 4, for example, so that the arm 5 is rotatable around a third axis A3 parallel to the first axis A1. The boom 4 is attached to the upper slewing body 3 via, for example, a boom foot pin provided on the upper slewing body 3 so as to be rotatable around a fourth axis A4 parallel to the first axis A1.

The bucket 6 is an example of a work tool (end attachment). The bucket 6 is used for, for example, excavation work. Instead of the bucket 6, another work tool may be attached to the distal end of the arm 5 depending on the work content or the like. The other work tool may be, for example, another type of bucket such as a large bucket, a slope bucket, or a dredging bucket. The attachment AT includes, for example, a tilt rotator TR. The tilt rotator TR is constituted by, for example, the rotator R and a tilt mechanism T.

The tilt mechanism T includes, for example, a base portion T1, a tilt axis T2, a support plate T3, and a tilt actuator T4. The base portion T1 is connected to the distal end of the arm 5 via an arm top pin so as to be rotatable around the first axis A1, and the tilt axis T2 is connected to the base portion T1. The support plate T3 is slewably supported with respect to the base portion T1 via the tilt axis T2, and the tilt actuator T4 change the tilt angle of the support plate T3. The tilt actuator T4 is constituted by, for example, hydraulic cylinders disposed on both sides of the tilt axis T2.

The rotator R includes, for example, a rotator motor R1, a rotator shaft R2, and a coupling portion R3. The rotator motor R1 is fixed to, for example, a support plate T3 of the tilt mechanism T. When the attachment AT does not include the tilt mechanism T, the rotator motor R1 may be fixed to a base portion connected to the arm 5, for example, similarly to the base portion T1 of the tilt mechanism T. One end of the rotator shaft R2 is connected to a rotation shaft of the rotator motor R1, and the other end of the rotator shaft is fixed to the coupling portion R3. The coupling portion R3 is connected to an end portion of the bucket 6 on the opposite side to the claw tip in the longitudinal direction D1 of the bucket 6.

The bucket 6 is attached to the arm 5 via, for example, the tilt mechanism T so as to be rotatable around a fifth axis A5 orthogonal to the first axis A1 and the second axis A2. The bucket 6 is attached to the arm 5 via, for example, the rotator R so as to be rotatable around the second axis A2 extending along the longitudinal direction D1 of the bucket 6.

A length L of the bucket 6 is, for example, a horizontal dimension from the claw tip of the bucket 6 to the end portion on the opposite side thereof measured in a direction orthogonal to the width direction Dw of the bucket 6 when the bucket 6 is placed on a horizontal surface in a state where the back surface of the bucket 6 is on the lower side. The length L of the bucket 6 may be, for example, a horizontal dimension from the claw tip of the bucket 6 to the end portion on the opposite side thereof measured in a direction orthogonal to the width direction Dw of the bucket 6 when the bucket 6 is placed on a horizontal surface in a state where the opening of the bucket 6 is directed downward.

The longitudinal direction D1 of the bucket 6 is, for example, a direction in which the length L of the bucket 6 is measured. The direction along the longitudinal direction D1 includes, for example, a direction parallel to the longitudinal direction D1 and a direction forming an acute angle equal to or smaller than a predetermined angle with respect to the longitudinal direction D1. The predetermined angle can be set to any angle such as 45°, 30°, 10°, or 5°.

A width W of the bucket 6 is, for example, the maximum dimension from one end to the other end of the bucket 6 in a direction orthogonal to the longitudinal direction D1 of the bucket 6 and crossing the opening of the bucket 6. The width direction Dw of the bucket 6 is, for example, a direction in which the width W of the bucket 6 is measured, and is a direction parallel to the width direction or the left-right direction of the upper slewing body 3.

The excavator 100 according to the present embodiment includes, for example, a controller 30 configured to control an operation of each part of the excavator 100 including the rotation of the bucket 6 by the rotator R. The controller 30 is an example of a control device, and is configured by a computer including a CPU, a volatile storage device, a nonvolatile storage device, various input/output interfaces, and the like, for example. The controller 30 reads the program from the nonvolatile storage device, loads the program into the volatile storage device, and causes the CPU to execute the program, thereby implementing various functions.

The controller 30 is configured to be able to control the excavator 100 by implementing various functions. The various functions include, for example, a machine guidance function of guiding the manual operation of the excavator 100 by the operator. The various functions may include, for example, a contact avoidance function of automatically or autonomously operating or stopping the excavator 100 in order to avoid contact between the excavator 100 and an object present in the monitoring range around the excavator 100.

The excavator 100 according to the present embodiment includes, for example, a slewing hydraulic motor 2A as an actuating device for slewing the upper slewing body 3 mounted on the lower traveling body 1 via the slewing mechanism 2. The excavator 100 according to the present embodiment includes, for example, a bucket cylinder 9, an arm cylinder 8, and a boom cylinder 7 as actuators configured to rotate the bucket 6, the arm 5, and the boom 4 around the first axis A1, the third axis A3, and the fourth axis A4, respectively.

The bucket cylinder 9, the arm cylinder 8, and the boom cylinder 7 are, for example, hydraulic cylinders. The slewing hydraulic motor 2A, the left traveling hydraulic motor 2ML, the right traveling hydraulic motor 2MR, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 are hydraulic actuators driven by the hydraulic fluid discharged from the hydraulic pumps. In the excavator 100, all or some of the driven parts such as the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6 may be electrically driven. That is, the excavator 100 may be a hybrid excavator, an electric excavator, or the like in which all or some of the driven parts are driven by electric actuators.

The excavator 100 according to the present embodiment includes, for example, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a bucket rotation sensor S3R, and a bucket tilt sensor S3T. These angle sensors may be, for example, a rotary encoder, an acceleration sensor, a six axis sensor, an inertial measurement unit (IMU), or the like, or may be a potentiometer using a variable resistor, a cylinder stroke sensor configured to detect a stroke amount of a hydraulic cylinder, or the like.

The boom angle sensor S1 detects a boom angle which is a rotation angle of the boom 4 around the fourth axis A4. The arm angle sensor S2 detects an arm angle which is a rotation angle of the arm 5 around the third axis A3. The bucket angle sensor S3 detects a bucket angle that is a rotation angle of the bucket 6 around the first axis A1. The bucket rotation sensor S3R detects a bucket rotation angle which is a rotation angle of the second axis A2 of the bucket 6. The bucket tilt sensor S3T detects a bucket tilt angle which is a rotation angle of the bucket 6 around the fifth axis A5. Signals related to the rotation angles around the respective axes detected by these angle sensors are incorporated into the controller 30.

The excavator 100 according to the present embodiment includes, for example, a body inclination sensor S4, a slewing sensor S5, an imaging device S6, a positioning device PS, and a communication device CD.

The body inclination sensor S4 detects an inclination state of the machine (the lower traveling body 1 or the upper slewing body 3) with respect to a horizontal plane. The body inclination sensor S4 is attached to, for example, the upper slewing body 3, and detects inclination angles of the excavator 100 (that is, the upper slewing body 3) around two axes in the front-rear direction and the right-left direction. The body inclination sensor S4 may be, for example, an accelerometer, a six axis sensor, or an IMU. A detection signal corresponding to the inclination angle by the body inclination sensor S4 is incorporated into the controller 30.

The slewing sensor S5 outputs information on the slewing of the upper slewing body 3. The slewing sensor S5 detects, for example, a slewing angular velocity of the upper slewing body 3 with respect to the lower traveling body 1. The slewing sensor S5 may detect a turning angle. The slewing sensor S5 may be, for example, a gyro sensor, a resolver, or a rotary encoder. A detection signal corresponding to the slewing angle or slewing angular velocity of the upper slewing body 3 by the slewing sensor S5 is incorporated into the controller 30.

The imaging device S6 is provided in the upper slewing body 3 or the operation cab 10, images the periphery of the excavator 100, and acquires image information representing the periphery of the excavator 100. In the illustrated example, the imaging device S6 includes a front camera S6F, a left camera S6L, a right camera S6R, and a rear camera S6B.

The front camera S6F is a camera configured to image the front of the excavator 100, and is attached to the outside of the operation cab 10, such as the roof of the operation cab 10 or the side surface of the boom 4. Note that the front camera S6F may be attached to the inside of the operation cab 10, such as the ceiling of the operation cab 10, for example. The left camera S6L is a camera configured to image the left side of the excavator 100, the right camera S6R is a camera configured to image the right side of the excavator 100, and the rear camera S6B is a camera configured to image the right side of the excavator 100. Specifically, each of the front camera S6F, the left camera S6L, the right camera S6R, and the rear camera S6B is a monocular wide-angle camera including an image sensor such as a CCD or a CMOS, and outputs a captured image to a display device D1 (see FIG. 2). Information on the image captured by the imaging device S6 is incorporated into the controller 30.

In the illustrated example, the front camera S6F is attached to the roof of the operation cab 10, the left camera S6L is attached to the left end of the upper surface of the upper slewing body 3, the right camera S6R is attached to the right end of the upper surface of the upper slewing body 3, and the rear camera S6B is attached to the rear end of the upper surface of the upper slewing body 3.

The imaging device S6 may be attached to the upper slewing body 3 and may form an object detection device configured to detect an object around the excavator 100. The object is, for example, a person, an animal, a vehicle, a construction machine, a building, a hole, or the like. The object detection device may be configured to be able to detect a person and an object other than a person in a distinguishable manner. That is, the object detection device may be configured to function as a human detection device.

The object detection device may be configured by a device other than a camera. For example, the object detection device may be a LiDAR. The LiDAR is, for example, a device capable of measuring a distance between a point group of one million or more points within a monitoring range and the LiDAR (laser source). The object detection device may be another device capable of measuring a distance to an object, such as a stereo camera, a range image camera, or a millimeter wave radar. When a millimeter wave radar or the like is used as the object detection device, the object detection device may derive a distance and an orientation of an object by transmitting a large number of signals (laser light or the like) toward the object and receiving the reflected signals. Alternatively, the object detection device may be a combination of two or more types of devices. For example, the object detection device may be a combination of an imaging device and a LiDAR, a combination of an imaging device and a millimeter wave radar, or a combination of an imaging device and a stereo camera.

The positioning device PS measures the position of the upper slewing body 3. The positioning device PS is, for example, a global navigation satellite system (GNSS) compass, and detects the position and orientation of the upper slewing body 3. Detection signals corresponding to the position and orientation of the upper slewing body 3 are incorporated into the controller 30. The function of detecting the orientation of the upper slewing body 3 may be implemented by an orientation sensor attached to the upper slewing body 3.

The communication device CD communicates with an external device through a communication network including a mobile communication network, a satellite communication network, the Internet, or the like. The communication device CD may be a mobile communication module compliant with a mobile communication standard such as Long Term Evolution (LTE), 4G (4th Generation), or 5G (5th Generation), a communication module compliant with a short-range wireless communication standard such as Wi-Fi (Registered Trademark) or Bluetooth (Registered Trademark), or a satellite communications module for connecting to a satellite communication network.

The excavator 100 operates the actuator in response to an operation of an operator in the operation cab 10, and operates the driven parts such as the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6. The excavator 100 may be configured to be remotely operated from the outside of the excavator 100. When the excavator 100 is remotely operated, the inside of the operation cab 10 may be in an unmanned state. The excavator 100 may automatically operate the actuator independent of the content of the operation by the operator. Thus, the excavator 100 implements a function of automatically operating at least some of the driven parts such as the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6, that is, a so-called “machine control function”.

As illustrated in FIG. 2, the drive system of the excavator 100 includes, for example, an engine 11, a regulator 13, a main pump 14, a pilot pump 15, a control valve unit 17, a discharge pressure sensor 28, and a valve 31. A hydraulic drive system of the excavator 100 includes hydraulic actuators such as the slewing hydraulic motor 2A, the left traveling hydraulic motor 2ML, the right traveling hydraulic motor 2MR, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the tilt actuator T4, and the rotator motor R1.

The engine 11 is an example of a power source of the excavator 100, and is mounted on, for example, a rear portion of the upper slewing body 3. The power source of the excavator 100 may be a combination of a power source such as a battery or a fuel cell and an electric motor. Specifically, the engine 11 rotates at a constant target rotation speed set in advance under direct or indirect control of the controller 30, and drives the main pump 14 and the pilot pump 15. The engine 11 is, for example, a diesel engine using diesel as fuel. The engine 11 may be a gasoline engine, a hydrogen engine, or the like.

The regulator 13 controls the discharge amount of the main pump 14. For example, the regulator 13 controls the discharge amount of the main pump 14 by adjusting the angle (tilting angle) of the swash plate of the main pump 14 in response to a control command from the controller 30.

The main pump 14 is mounted, for example, on the rear portion of the upper slewing body 3 similarly to the engine 11, and supplies the hydraulic fluid to the control valve unit 17 through the hydraulic fluid line. In the illustrated example, the main pump 14 is a variable displacement hydraulic pump.

The control valve unit 17 is one of hydraulic control devices that control a hydraulic system in the excavator 100. In the illustrated example, the control valve unit 17 includes control valves 171 to 178. The control valve unit 17 is configured to be able to selectively supply the hydraulic fluid discharged by the main pump 14 to one or a plurality of hydraulic actuators through the control valves 171 to 178. The control valves 171 to 178 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 actuators include the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the tilt actuator T4, the left traveling hydraulic motor 2ML, the right traveling hydraulic motor 2MR, the slewing hydraulic motor 2A, and the rotator motor R1. Specifically, the control valve 171 corresponds to the boom cylinder 7, the control valve 172 corresponds to the arm cylinder 8, the control valve 173 corresponds to the bucket cylinder 9, and the control valve 174 corresponds to the tilt actuator T4. The control valve 175 corresponds to the right traveling hydraulic motor 2MR, the control valve 176 corresponds to the left traveling hydraulic motor 2ML, the control valve 177 corresponds to the slewing hydraulic motor 2A, and the control valve 178 corresponds to the rotator motor R1.

The pilot pump 15 is an example of a pilot pressure generation device and is configured to be able to supply the hydraulic fluid to the hydraulic control device via a pilot line. In the illustrated example, the pilot pump 15 is a fixed displacement hydraulic pump. However, the pilot pressure generation device may be implemented by the main pump 14. That is, the main pump 14 may have a function of supplying the hydraulic fluid to various hydraulic control devices via the pilot line, in addition to the function of supplying the hydraulic fluid to the control valve unit 17 via the hydraulic fluid line. In this case, the pilot pump 15 may be omitted.

The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In the illustrated example, the discharge pressure sensor 28 outputs the detected value to the controller 30.

The excavator 100 includes, for example, an operation device 26 including an operation sensor 29 configured to detect operation amounts of the boom 4, the arm 5, and the bucket 6 by the operator. The operation device 26 is a device used by an operator to operate the actuator. The actuator may be a hydraulic actuator or an electric actuator. The operation device 26 includes, for example, a left operation lever, a right operation lever, a left travel pedal, a right travel pedal, a left travel lever, a right travel lever, a left operation pedal, a right operation pedal, a left operation switch, a right operation switch, and the like.

The operation sensor 29 is configured to detect the content of an operation performed by the operator using the operation device 26. In the present embodiment, the operation sensor 29 detects the operation direction and the operation amount of the operation device 26 corresponding to each of the actuators, and outputs the detected values to the controller 30. In the illustrated example, the controller 30 can control the opening area of the valve 31 in accordance with the output of the operation sensor 29. The controller 30 supplies the hydraulic fluid discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17. The pressure of the hydraulic fluid (pilot pressure) supplied to each of the pilot ports is, in principle, a pressure corresponding to the operation direction and the operation amount of the operation device 26 corresponding to each of the hydraulic actuators. In this way, the operating device 26 is configured to be able to supply the hydraulic fluid discharged by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17.

The operator can drive the arm cylinder 8 and the slewing hydraulic motor 2A by operating the left operation lever of the operation device 26 with the left hand, for example. The operator can also drive the boom cylinder 7 and the bucket cylinder 9 by operating the right operation lever of the operation device 26 with the right hand, for example. The operator can also drive the left traveling hydraulic motor 2ML by operating the left traveling pedal of the operation device 26 with the left foot, for example. Further, the operator can drive the right traveling hydraulic motor 2MR by operating the right traveling pedal of the operation device 26 with the right foot, for example.

Further, the operator can drive the left traveling hydraulic motor 2ML by operating the left traveling lever of the operating device 26 while gripping the left traveling lever with the left hand, for example, in the same manner as the operation via the left traveling pedal. Further, the operator can drive the right traveling hydraulic motor 2MR by operating the right traveling lever of the operating device 26 while gripping the right traveling lever with the right hand, for example, similarly to the operation via the right traveling pedal. The left traveling lever and the right traveling lever of the operation device 26 are arranged so that the operator can operate the left traveling lever and the right traveling lever simultaneously with one hand.

The operator can also drive the tilt actuator T4 by operating the right operation pedal of the operation device 26 with the right foot or operating the right operation switch provided on the right operation lever of the operation device 26 with the right hand, for example. The operator can also drive the rotator motor R1 by operating the left operation pedal of the operation device 26 with the left foot or operating the left operation switch provided on the left operation lever of the operation device 26 with the left hand, for example.

The valve 31 functioning as a control valve for machine control is disposed in a conduit connecting the pilot pump 15 and a pilot port of a control valve in the control valve unit 17, and is configured to be able to change a flow passage area of the conduit. In the illustrated example, the valve 31 is an electromagnetic valve that operates in response to a control command output from the controller 30. Therefore, the controller 30 can adjust the pilot pressure acting on the pilot port of the control valve by the valve 31, independently of the operation of the operating device 26 by the operator.

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

The controller 30 is configured to be able to output a control command to the regulator 13 as necessary and change the discharge amount of the main pump 14.

Further, the controller 30 may be configured to perform control related to a machine guidance function of guiding (leading) a manual operation of the excavator 100 by the operator through the operation device 26, for example. Further, the controller 30 may be configured to perform control related to a machine control function of automatically supporting manual operation of the excavator 100 by the operator through the operation device 26, for example.

Note that some of the functions of the controller 30 may be implemented by another controller (control device). That is, the functions of the controller 30 may be implemented in a distributed manner by a plurality of controllers. For example, the machine guidance function and the machine control function may be implemented by a dedicated controller (control device).

The display device D1 is provided at a position in the operation cab 10 where the display device D1 is easily visible to the seated operator, and displays various information images under the control of the controller 30. In the illustrated example, the display device D1 is disposed in front of the right side of the operator's seat in the operation cab 10, and is connected to the controller 30 via a dedicated line. The display device D1 displays various kinds of image information. The display device D1 includes a display screen that displays information such as a work condition or an operation state of the excavator 100. The operator seated on the operator's seat can perform work with the excavator 100 while checking various information displayed on the display device D1. The display device D1 may be provided with an input device D2.

The input device D2 is provided within reach of an operator seated on an operator's seat in the operation cab 10, receives various operation inputs from the operator, and outputs a signal corresponding to the operation input to the controller 30. The input device D2 includes a touch panel mounted on a display of the display device D1 that displays various information images, a knob switch provided at a tip of one or more lever portions of a plurality of operation levers included in the operation device 26, or a button switch, a lever, a toggle switch, a rotary dial, or the like installed around the display device D1. A signal corresponding to the content of the operation on the input device D2 is incorporated into the controller 30.

FIG. 3 is a functional block diagram illustrating machine control functions of the controller 30 illustrated in FIG. 2. FIG. 4 is a flow diagram illustrating the machine control functions of the controller 30. FIG. 5 is a schematic plan view illustrating an example of excavation work of a construction surface by the attachment AT of the excavator 100. Hereinafter, the “machine control function” may be referred to as an “MC function”.

The controller 30 of the present embodiment includes, for example, as illustrated in FIG. 3, an operation content acquisition part 3001, a target surface acquisition part 3002, a target trajectory setting part 3003, a current position calculation part 3004, a target position calculation part 3005, and a bucket shape acquisition part 3006. The controller 30 includes, for example, a primary element setting part 3007, a control reference setting part 3008, a primary command value generation part 3009, and a secondary command value generation part 3010.

Further, the controller 30 includes, for example, a boom command generation part 3011, an arm command generation part 3012, a bucket command generation part 3013, a bucket tilt command generation part 3013T, and a bucket rotation command generation part 3013R. Each part of the controller 30 illustrated in FIG. 3 represents, for example, each function of the controller 30. Specifically, each function of the controller 30 is implemented by, for example, the CPU of the controller 30 reading a program stored in the nonvolatile storage device, loading the program into the volatile storage device, and executing the program.

The operation content acquisition part 3001 acquires the operation content of the operation device 26 by the operator detected by the operation sensor 29. The operation contents of the operation device 26 include, for example, rotations of the left crawler 1CL and the right crawler 1CR by the left traveling hydraulic motor 2ML and the right traveling hydraulic motor 2MR, the slewing of the upper slewing body 3 by the slewing hydraulic motor 2A of the slewing mechanism 2, and the operation contents of the attachment AT. The operation contents of the attachment AT include, for example, the rotation of the boom 4 by the boom cylinder 7, the rotation of the arm 5 by the arm cylinder 8, the rotation of the bucket 6 by the bucket cylinder 9, the tilting of the bucket 6 by the tilt actuator T4, and the rotation of the bucket 6 by the rotator motor R1. The operation content of the operation device 26 includes an operation direction and an operation amount.

The target surface acquisition part 3002 acquires, for example, information on the target surface input to the controller 30 via the input device D2. The information on the target surface may be downloaded and acquired from an external server by the target surface acquisition part 3002, for example. The target surface is, for example, a surface that is a target when excavating a ground surface that is a construction surface in a ground leveling work or a slope face maintenance work by the excavator 100. That is, the target surface is, for example, a flat surface or a slope surface formed by excavating the construction surface with the bucket 6. The target surface may be, for example, a curved surface or a surface having a predetermined unevenness.

The information on the target surface is expressed by, for example, a reference coordinate system. The reference coordinate system is, for example, a world geodetic system. The world geodetic system is a three dimensional orthogonal XYZ coordinate system with the origin at the center of gravity of the earth, the X-axis in the direction of the intersection of the Greenwich meridian and the equator, the Y-axis in the direction of 90 degrees east longitude, and the Z-axis in the direction of the north pole. For example, the operator sets any given point in the construction site as a reference point via the input device D2, and sets the target surface based on a relative positional relationship with the reference point.

The target trajectory setting part 3003 sets a target trajectory of the control reference for moving the control reference of the attachment AT along the target surface based on the acquired information related to the target surface. As the control reference of the attachment AT, for example, the claw tip, the back surface, or the like of the bucket 6 as the end attachment attached to the tip of the attachment AT is set. The control criterion of the attachment AT is set by, for example, the control reference setting part 3008 of the controller 30.

The control reference setting part 3008 receives, for example, an input of a control criterion by the manipulator via the input device D2 and sets the control criterion of the attachment AT. The control reference setting part 3008 may automatically set the control criterion of the attachment AT in response to the establishment of a predetermined condition, for example.

The current position calculation part 3004 calculates the current position of the control reference of the attachment AT, such as the claw tip of the bucket 6. Specifically, the current position calculation part 3004 acquires a boom angle θ1, an arm angle θ2, a bucket angle 03, a bucket tilt angle θ3T, and a bucket rotation angle θ3R from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the bucket tilt sensor S3T, and the bucket rotation sensor S3R. Then, the current position calculation part 3004 calculates the current position of the control reference of the attachment AT, for example, the claw tip of the bucket 6, based on the angle of each part of the attachment AT acquired from each angle sensor.

The target position calculation part 3005 calculates the target position of the control reference set by the control reference setting part 3008 based on the operation content by the operator acquired by the operation content acquisition part 3001 and the target trajectory set by the target trajectory setting part 3003, for example, in order to implement the MC function. For example, when the control reference is the claw tip of the bucket 6, the target position of the control reference is a position on the target trajectory that the claw tip of the bucket 6 should reach during the current control cycle when it is assumed that the arm 5 operates in accordance with the operation direction and the operation amount included in the operation content by the operator. The target position calculation part 3005 can calculate the target position of the control reference by using, for example, a map, an arithmetic expression, or the like stored in advance in the nonvolatile storage device.

Further, for example, in order to implement the MC function, the target position calculation part 3005 may acquire the operation command generated by the operation content acquisition part 3001, the target trajectory set by the target trajectory setting part 3003, and the current position of the control reference of the attachment AT calculated by the current position calculation part 3004. In this case, the target position calculation part 3005 calculates the target position of the control reference of the attachment AT based on these pieces of information. Thus, the controller 30 can autonomously control the excavator 100 without depending on the operation of the operator.

The bucket shape acquisition part 3006 acquires, for example, information on the shape of the bucket 6 stored in advance in the nonvolatile storage device. The bucket shape acquisition part 3006 may acquire information on the shape of a specific bucket 6 by selection of the operator via the input device D2 from among information on the shapes of a plurality of types of buckets stored in the nonvolatile storage device, for example.

The primary element setting part 3007 selects and sets a primary element from respective parts such as the boom 4, the arm 5, and the bucket 6 constituting the attachment AT. The primary element is a component that operates in accordance with the operation content of the operation device 26 by the operator in the MC function, for example. The primary element setting part 3007 selects and sets a primary element, for example, based on an operation mode of the excavator 100 input by the operator via the input device D2. The primary element setting part 3007 may select and set a primary element based on, for example, the operation content of the operation device 26 by the operator, the information on the target surface, the current position of the control reference of the attachment AT, the detection result of each angle sensor, and the like.

The primary command value generation part 3009 generates, for example, a command value for the primary element set by the primary element setting part 3007. In the example illustrated in FIG. 3, the arm 5 is set as a primary element by the primary element setting part 3007. In this case, the primary command value generation part 3009 generates a command value for operating the arm cylinder 8 in accordance with the operation content of the arm 5 by the operator acquired by the operation content acquisition part 3001, and outputs the command value to the arm command generation part 3012, for example.

The secondary command value generation part 3010 generates, for example, command values to control the operations of secondary elements, which are components of the attachment AT excluding the primary element, in accordance with the operation of the primary element set by the primary element setting part 3007. Specifically, the secondary command value generation part 3010 calculates the angular velocity of the secondary element based on the angular velocity of the primary element, the information on the target surface, and the current position of the control reference such that the angular velocity of the primary element and the angular velocity of the secondary element satisfy a predetermined condition.

In the example illustrated in FIG. 3, the arm 5 is set as a primary element by the primary element setting part 3007. In this case, the secondary command value generation part 3010 calculates, for example, the angular velocity of the boom 4 as the secondary element. Further, the secondary command value generation part 3010 calculates, for example, the angular velocity around the first axis A1 by the bucket cylinder 9, the angular velocity around the second axis A2 by the rotator R, and the angular velocity around the fifth axis A5 by the tilt mechanism T, for the bucket 6 as the secondary element.

Further, the secondary command value generation part 3010 generates command values for operating the boom cylinder 7, the bucket cylinder 9, the rotator motor R1, and the tilt actuator T4 in accordance with the calculated angular velocities of the secondary elements. The secondary command value generation part 3010 outputs the generated command values corresponding to the operations of the secondary elements to the boom command generation part 3011, the bucket command generation part 3013, the bucket tilt command generation part 3013T, and the bucket rotation command generation part 3013R, respectively.

The boom command generation part 3011 acquires, for example, the command value input from the primary command value generation part 3009 or the secondary command value generation part 3010 and the angular velocity of the boom 4 based on the boom angle θ1 detected by the boom angle sensor S1. The boom command generation part 3011 generates a pilot pressure command value to be applied to the control valve 171 corresponding to the boom cylinder 7 illustrated in FIG. 2 based on the deviation between the acquired command value and the angular velocity, and outputs the pilot pressure command value to the valve 31.

The arm command generation part 3012 acquires, for example, the command value input from the primary command value generation part 3009 or the secondary command value generation part 3010 and the angular velocity of the arm 5 based on the arm angle 62 detected by the arm angle sensor S2. The arm command generation part 3012 generates a pilot pressure command value to be applied to the control valve 172 corresponding to the arm cylinder 8 illustrated in FIG. 2 based on the deviation between the acquired command value and the angular velocity, and outputs the pilot pressure command value to the valve 31.

The bucket command generation part 3013 acquires, for example, the command value input from the primary command value generation part 3009 or the secondary command value generation part 3010 and the angular velocity of the bucket 6 based on the bucket angle 63 detected by the bucket angle sensor S3. The bucket command generation part 3013 generates a pilot pressure command value to be applied to the control valve 173 corresponding to the bucket cylinder 9 illustrated in FIG. 2 based on the deviation between the acquired command value and the angular velocity, and outputs the pilot pressure command value to the valve 31.

The bucket tilt command generation part 3013T acquires, for example, the command value input from the primary command value generation part 3009 or the secondary command value generation part 3010 and the angular velocity of the bucket 6 based on the bucket tilt angle θ3T detected by the bucket tilt sensor S3T. The bucket tilt command generation part 3013T generates a pilot pressure command value to be applied to the control valve 174 corresponding to the tilt actuator T4 illustrated in FIG. 2 based on the deviation between the acquired command value and the angular velocity, and outputs the pilot pressure command value to the valves 31.

The bucket rotation command generation part 3013R acquires, for example, the command value input from the primary command value generation part 3009 or the secondary command value generation part 3010 and the angular velocity of the bucket 6 based on the bucket rotation angle θ3R detected by the bucket rotation sensor S3R. The bucket rotation command generation part 3013R generates a pilot pressure command value to be applied to the control valve 178 corresponding to the rotator motor R1 illustrated in FIG. 2 based on the deviation between the acquired command value and the angular velocity, and outputs the pilot pressure command value to the valves 31.

With such a configuration, the controller 30 can cause a component set as a primary element among the plurality of elements constituting the attachment AT to operate in accordance with the operation content of the operation device 26 by the operator, for example. The controller 30 can operate the other components as secondary elements that are not set as a primary element among the plurality of elements constituting the attachment AT in accordance with the operation of the primary element independent of the operation content of the operation device 26 by the operator.

Next, the MC function of the excavator 100 will be described with reference to FIGS. 4 to 6. FIG. 4 is a flowchart illustrating an example of a process of the controller 30 for implementing the MC function of the excavator 100. FIG. 5 is a plan view illustrating an example of the excavation work of the construction surface GS by the attachment AT of the excavator 100 according to the present embodiment. FIG. 6 is a plan view illustrating an example of excavation work of the construction surface GS by an attachment of an excavator according to a comparative example different from the excavator 100 according to the present embodiment.

The excavation work performed by the excavator 100 includes, for example, ground leveling work or slope face maintenance work for excavating a construction surface GS, which is a ground surface before construction, with the bucket 6 of the attachment AT to form a preset target surface TS.

As illustrated in FIG. 6, the attachment of the excavator according to the comparative example different from the excavator 100 according to the present embodiment does not rotate the bucket 6 around the second axis A2 along the longitudinal direction D1 illustrated in FIG. 1 when the bucket 6 excavates the construction surface GS. Therefore, the claw tip of the bucket 6 (for example, a straight line connecting the tips of the plurality of claws provided at the tip of the bucket 6) is orthogonal to a moving direction MD of the bucket 6 during excavation. In this case, when the construction surface GS is excavated in the first excavation work in which the bucket 6 is moved from the back to the front of the construction surface GS along the moving direction MD, the earth and sand ES overflows on both sides of the bucket 6.

Therefore, in the second and subsequent excavation work, in order to prevent the earth and sand ES from overflowing to the rear side in a work progress direction PD of the bucket 6, it is necessary to overlap a range of the excavation work with a range excavated in the previous excavation work by a predetermined overlap width Wd. As the overlap width Wd increases, the number of times of excavation work required to excavate the entire construction surface GS increases, and the work efficiency of the excavator decreases.

In contrast, in the excavator 100 according to the present embodiment, the attachment AT includes the rotator R as illustrated in FIG. 1. When the bucket 6 excavates the construction surface GS as illustrated in FIG. 5, the rotator R rotates the bucket 6 around the second axis A2 extending along the longitudinal direction D1 illustrated in FIG. 1 to cause the earth and sand ES to overflow to one side of the bucket 6. Thus, in the second and subsequent excavation work by the bucket 6, the overlap width Wd in which the range of the excavation work overlaps the range of the previous excavation work can be reduced, and the work efficiency of the excavator 100 can be improved.

The excavator 100 according to the present embodiment performs the excavation work illustrated in FIG. 5 by the attachment AT by executing each process illustrated in FIG. 4 by the controller 30 to support the operator by the MC function, for example.

When a sequence of processes of the flowchart illustrated in FIG. 4 is started, the controller 30 first executes a process P01 of acquiring information on the target surface TS. In the process P01, the controller 30 acquires, for example, information on the target surface TS input via the input device D2 and stored in the nonvolatile storage device by the target surface acquisition part 3002.

Next, the controller 30 executes, for example, a process P02 of calculating a target illustrated in FIG. 4. In this process P02, the target trajectory setting part 3003 sets, for example, a target trajectory for moving the control reference of the attachment AT along the target surface TS. Here, for example, the control reference of the attachment AT is set to the claw tip of the bucket 6 by the control reference setting part 3008. In the process P02, the bucket shape acquisition part 3006 acquires information on the shape of the bucket 6, and the current position calculation part 3004 calculates the current position of the claw tip of the bucket 6.

Next, the controller 30 executes a process P03 of acquiring the overlap width Wd of the excavation work, for example, as illustrated in FIG. 4. The overlap width Wd of the excavation work is input by the operator via the input device D2 and stored in the nonvolatile storage device, for example. In this case, for example, the target position calculation part 3005 acquires the overlap width Wd stored in the nonvolatile storage device.

Further, the overlap width Wd required for the excavation work varies in accordance with an angle θb between the claw tip of the bucket 6 (for example, a straight line connecting the tips of the plurality of claws provided at the tip of the bucket 6) and the work progress direction PD, for example, as illustrated in FIG. 5. Therefore, the overlap width Wd of the excavation work is stored in advance in the nonvolatile storage device as a table or a function indicating a relationship with the angle θb, for example. In this case, the target position calculation part 3005 acquires the overlap width Wd corresponding to the angle θb based on, for example, a table or a function stored in the nonvolatile storage device.

Next, the controller 30 executes, for example, a process P04 of setting the work progress direction PD. The controller 30 can set the work progress direction PD in advance, for example. Specifically, the work progress direction PD is input by the operator via the input device D2, for example, and stored in a volatile storage device or a nonvolatile storage device constituting the controller 30. In this case, for example, the target position calculation part 3005 acquires the work progress direction PD stored in the volatile storage device or the nonvolatile storage device.

Further, for example, as illustrated in FIG. 5, the controller 30 may estimate the work progress direction PD based on the start position of the second excavation work with respect to the range of the first excavation work. That is, the controller 30 can predict the work progress direction PD based on the moving direction of the bucket 6 between the first excavation and the second excavation of the construction surface GS. Specifically, the target position calculation part 3005 can estimate the work progress direction PD, for example, based on the position information of the bucket 6 in the first excavation work and the position information of the bucket 6 in the second excavation work. In this case, the controller 30 may omit the process P04.

Next, the controller 30 executes a process P05 of acquiring permission or non-permission of the MC function, for example, as illustrated in FIG. 4. In the process P05, the controller 30 displays a menu for selecting permission or non-permission of the MC function on the display device D1, and receives an input of permission or non-permission of the MC function through the input device D2. The controller 30 stores information on permission or non-permission of the MC function input via the input device D2 in the volatile storage device or the non-volatile storage device, for example.

Next, the controller 30 executes a process P06 of determining whether or not the MC function is permitted, for example, as illustrated in FIG. 4. In this process P06, the controller 30 refers to, for example, information on permission or non-permission of the MC function stored in the volatile storage device or the non-volatile storage device in the previous process P05. In the process P06, for example, when the referred information is non-permission (NO) of the MC function, the controller 30 ends the sequence of processes of the flowchart illustrated in FIG. 4 and returns to the normal mode of the excavator 100 in which the MC function is not used.

In the process P06, for example, when the referred information is permission (YES) of the MC function, the controller 30 enables the MC function of the excavator 100 using the functions illustrated in FIG. 3, and executes a process P07 of acquiring the operation content of the operation device 26 by the operator.

In the process P07, the controller 30 acquires, for example, the operation content of the operation device 26 by the operator via the operation sensor 29 by the operation content acquisition part 3001. Thereafter, the controller 30 executes machine control (MC) by each part illustrated in FIG. 3 (process P08).

Specifically, for example, the controller 30 controls the actuator and the rotator R based on the operation amount of the arm 5 detected by the operation device 26 and the rotation angle detected by the angle sensor when the bucket 6 excavates the construction surface GS. The operation device 26 includes the operation sensor 29, and the angle sensor includes the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the bucket tilt sensor S3T, and the bucket rotation sensor S3R. The rotation angle detected by the angle sensor includes the boom angle θ1, the arm angle θ2, the bucket angle θ3, the bucket tilt angle θ3T, and the bucket rotation angle θ3R. The actuators include the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the tilt actuator T4.

As a result, the operator of the excavator 100 can operate the arm 5 as a primary element by operating the left operation lever of the operation device 26, for example, and can operate the boom 4 and the bucket 6 in accordance with the operation of the arm 5.

As illustrated in FIG. 5, the MC function of the excavator 100 allows the rotator R of the attachment AT to rotate the bucket 6 to rotate around the second axis A2 along the longitudinal direction D1 and to cause the earth and sand ES to overflow to one side of the bucket 6 when the bucket 6 excavates a construction surface GS. In other words, in the excavator 100 according to the present embodiment, the controller 30 controls the rotator R so as to cause the bucket 6 to rotate around the second axis A2 along the longitudinal direction D1 and cause the earth and sand ES to overflow to one side of the bucket 6 when the bucket 6 excavates the construction surface GS.

When excavating the construction surface GS, the operator of the excavator 100 alternately repeats the excavation work and the progression work by operating the operation device 26, for example. The excavation work is, for example, work of scraping off earth and sand from the construction surface GS by moving the claw tip of the bucket 6 from the back to the front of the construction surface GS in the moving direction MD along the target surface TS. The progression work is, for example, work of moving the bucket 6 in the work progress direction PD for the next excavation work after one excavation work of moving the bucket 6 in the moving direction MD is finished. The moving direction MD of the bucket 6 during the excavation work and the work progress direction PD are directions intersecting with each other. In the example illustrated in FIG. 5, the moving direction MD of the bucket 6 and the work progress direction PD are orthogonal to each other.

In the excavator 100 according to the present embodiment, one side of the bucket 6 where the rotator R causes the earth and sand ES to overflow is the front side in the work progress direction PD intersecting the moving direction MD of the bucket 6 during the excavation of the construction surface GS. That is, in the excavator 100 according to the present embodiment, the rotator R rotates the bucket 6 in a rotation direction in which the opening surface of the bucket 6 faces the work progress direction PD when the construction surface GS is excavated. In other words, in the excavator 100 according to the present embodiment, the controller 30 controls the rotator R so as to rotate the bucket 6 in a rotation direction in which the opening surface of the bucket 6 faces the work progress direction PD when the bucket 6 excavates the construction surface GS. The angle at which the rotator R rotates the bucket 6 around the second axis A2 is, for example, 90° or less.

When one excavation work in which the claw tip of the bucket 6 is moved along the target surface TS in the moving direction MD from the back to the front of the construction surface GS is finished, the controller 30 executes, for example, a process P09 of determining whether or not the construction is completed as illustrated in FIG. 4. In this process P09, when the excavation of the entire target surface TS is not completed, the controller 30 repeats the process P07 of acquiring the operation content by the operator and the process P08 of executing the machine control.

For example, when one excavation work of moving the claw tip of the bucket 6 along the target surface TS in the moving direction MD from the back to the front of the construction surface GS is finished, the operator of the excavator 100 moves the bucket 6 in the work progress direction PD. Specifically, the operator moves the bucket 6 in the work progress direction PD by operating the operation device 26 to move the excavator 100 via the lower traveling body 1, for example. At this time, the operator of the excavator 100 causes the range excavated in the next excavation work to overlap the range excavated in the previous excavation work by a predetermined overlap width Wd.

The overlap width Wd of the work range can be determined, for example, based on the width Wes of the earth and sand ES that overflows to the side of the bucket 6 during the excavation work. In the excavator 100 according to the present embodiment, when the bucket 6 excavates the construction surface GS, the rotator R rotates the bucket 6 around the second axis A2 along the longitudinal direction D1 to cause the earth and sand ES to overflow to one side of the bucket 6.

In this case, the overlap width Wd required for the excavation work of the construction surface GS changes according to the orientation of the bucket 6, that is, the angle θb of the claw tip of the bucket 6 with respect to the work progress direction PD illustrated in FIG. 5. The correlation between the overlap width Wd and the angle θb of the claw tip of the bucket 6 can be specified in advance and stored in the nonvolatile storage device constituting the controller 30 as a table or a mathematical expression, for example. The controller 30 causes the display device D1 to display the overlap width Wd corresponding to the angle θb, for example. The operator causes the excavation range to overlap the overlap width Wd displayed on the display device D1.

For example, in the process P08 of executing the machine control, the controller 30 controls the bucket rotation angle θ3R, which is the rotation angle of the bucket 6 by the rotator R around the second axis A2, as follows. The controller 30 controls the bucket rotation angle θ3R so that the number of times N of the excavation work is minimized, for example, based on the width Wgs of the construction surface GS, the width W of the bucket 6, the bucket rotation angle θ3R, and the overlap width Wd of the excavation work of the construction surface GS by the bucket 6.

The number of times N of the excavation work can be expressed by the following Equation (1) using, for example, the width Wgs of the construction surface GS, the width W of the bucket 6, the angle θb (0<θb<π/2) with respect to the work progress direction PD of the bucket 6, and a ratio P (=Wd/W) of the overlap width Wd of the excavation work to the width W of the bucket, as illustrated in FIG. 5.

N = Wgs / ( W · cos ⁢ ⁢ θ ⁢ ⁢ b - P · W ) ( 1 )

The work efficiency E=N0/N1 when the angle θb of the bucket 6 is changed from θb0 to θb1 and the overlap width Wd of the excavation work is changed from Wd0 to Wd1 can be expressed by the following Equation (2).

E = N ⁢ 0 / N ⁢ 1 = ( cos ⁢ ⁢ θ ⁢ ⁢ b ⁢ ⁢ 1 - ⁢ P ⁢ ⁢ 1 ) / ( cos ⁢ ⁢ θ ⁢ ⁢ b ⁢ ⁢ 0 ⁢ - ⁢ P ⁢ ⁢ 0 ) ( 2 )

In particular, as illustrated in FIG. 6, when there is a ratio P0=X between the widths W of the bucket 6 and the overlap widths Wd of the excavation work required when the angle θb0 of the bucket 6 is 0 (θb0=0), the work efficiencies E can be expressed by the following Equation (3).

E = N ⁢ ⁢ 0 / N ⁢ ⁢ 1 = ( cos ⁢ ⁢ θ ⁢ ⁢ b ⁢ ⁢ 1 - P ⁢ ⁢ 1 ) / ( 1 - X ) ( 3 )

Here, the ratio P (=Wd/W) of the overlap width Wd of the excavation work to the width W of the bucket changes according to the angle θb of the bucket 6, and thus P=P(θb).

Therefore, the work efficiency E can be expressed by the following Equation (4).

E = { cos ⁢ ⁢ θ ⁢ ⁢ b ⁢ ⁢ 1 - P ⁡ ( θ ⁢ ⁢ b ⁢ ⁢ 1 ) } / ( 1 - X ) = E ⁡ ( θ ⁢ ⁢ b ⁢ ⁢ 1 ) ( 4 )

Therefore, the angle θb of the bucket 6 that maximizes the work efficiency E(θb) can be obtained by specifying in advance the relationship between the ratio P (=Wd/W) and the angle θb of the bucket 6, that is, the relationship between the width Wes of the earth and sand ES overflowing from the bucket 6 and the angle θb. Therefore, the controller 30 can minimize the number of times N of the excavation work by controlling the bucket rotation angle θ3R of the bucket 6 by the rotator R so as to maintain the angle θb of the bucket 6 at which the work efficiency E(θb) is maximized.

Thereafter, when the excavation work and the movement of the bucket 6 in the work progress direction PD are repeated, the entire construction surface GS is excavated, and the entire target surface TS is formed, the controller 30 determines that the construction is completed (YES) in the process P09 illustrated in FIG. 4. Thereafter, the controller 30 executes the process P10 of ending the machine control, and ends the process flow illustrated in FIG. 4.

As described above, the excavator 100 according to the present embodiment includes the lower traveling body 1, the upper slewing body 3 slewably provided on the lower traveling body 1, and the attachment AT provided on the upper slewing body 3. The attachment AT includes the bucket 6 rotatable around a first axis A1 along the width direction Dw, and the rotator R configured to rotate the bucket 6 around the second axis A2 along the longitudinal direction D1 to cause earth and sand to overflow to one side of the bucket 6 when the bucket 6 excavates the construction surface GS.

With such a configuration, in the excavator 100 according to the present embodiment, it is possible to reduce the overlap width Wd by which the range of the second and subsequent excavation work overlaps the range of the previous excavation work, compared to a case where the earth and sand ES is caused to overflow to both sides of the bucket 6 during the excavation of the construction surface GS. Thus, the number of times of excavation work during excavation of the construction surface GS can be reduced as compared to a case where the earth and sand ES is caused to overflow to both sides of the bucket 6 during excavation of the construction surface GS. Therefore, in the excavator 100 according to the present embodiment, the work efficiency E can be improved.

In the excavator 100 according to the present embodiment, one side of the bucket 6 where the earth and sand ES overflows is the front side in the work progress direction PD intersecting the moving direction MD of the bucket 6 during the excavation of the construction surface GS.

With such a configuration, the bucket 6 is moved in the work progress direction PD in the second and subsequent excavation work, and the earth and sand ES that has overflowed to one side of the bucket 6 in the previous excavation work can be removed by the bucket 6 in the next excavation work. In other words, after one excavation work in which the bucket 6 is moved in the moving direction MD from the back of the construction surface GS toward the front thereof, it is not necessary to move the bucket 6 in the direction opposite to the work progress direction PD in order to remove the earth and sand ES that has overflowed to the side of the bucket 6. Therefore, in the excavator 100 according to the present embodiment, it is possible to improve the work efficiency E when the excavation work of excavating the construction surface GS from the back to the front by the bucket 6 and the movement of the bucket 6 in the work progress direction PD are repeated to excavate the construction surface GS.

In the excavator 100 according to the present embodiment, the rotator R rotates the bucket 6 in the rotation direction in which the opening surface of the bucket 6 faces the work progress direction PD during the excavation of the construction surface GS.

With such a configuration, when the bucket 6 is moved in the moving direction MD along the target surface TS from the back to the front of the construction surface GS to excavate the construction surface GS, the earth and sand ES can be made to overflow from the opening of the bucket 6 to the front side in the work progress direction PD. Therefore, in the excavator 100 according to the present embodiment, the work efficiency E can be improved. The expression “from the back to the front of the construction surface GS” can be rephrased as “from any given point on the construction surface GS located on the front side of the upper slewing body 3 to a point on the construction surface GS closer to the upper slewing body 3”.

The excavator 100 according to the present embodiment further includes the controller 30 configured to control the rotation of the bucket 6 by the rotator R. The controller 30 is capable of predicting the work progress direction PD based on the moving direction of the bucket 6 between the first excavation and the second excavation of the construction surface GS, or capable of setting the work progress direction PD in advance. With such a configuration, the controller 30 is capable of rotating the bucket 6 so as to face the predicted work progress direction PD after the first excavation work, or capable of rotating the bucket 6 from the beginning so as to face the preset work progress direction PD.

In the excavator 100 according to the present embodiment, the controller 30 controls the bucket rotation angle θ3R so that the number of times N of the excavation work is minimized based on the width of the construction surface GS, the width W of the bucket 6, the bucket rotation angle θ3R which is the rotation angle of the bucket 6 around the second axis A2, and the overlap width Wd of the construction surface GS subject to the excavation work by the bucket 6. With such a configuration, in the excavator 100 according to the present embodiment, the work efficiency E can be maximized as compared with the case where the bucket 6 is not rotated around the second axis A2.

In the excavator 100 according to the present embodiment, the attachment AT includes the arm 5 that supports the bucket 6 rotatably around the first axis A1, and the boom 4 that supports the arm 5 rotatably around the third axis A3 parallel to the first axis A1 and is attached to the upper slewing body 3 rotatably around the fourth axis A4 parallel to the first axis A1. With such a configuration, the excavator 100 according to the present embodiment can rotate the boom 4, the arm 5, and the bucket 6 around the fourth axis A4, the third axis A3, and the first axis A1, respectively, and can move the claw tip of the bucket 6 from the back to the front of the construction surface GS in the moving direction MD along the target surface TS.

The excavator 100 according to the present embodiment further includes actuators, angle sensors, and an operation device 26. The actuators include the bucket cylinder 9, the arm cylinder 8, and the boom cylinder 7, and rotate the bucket 6, the arm 5, and the boom 4 around the first axis A1, the third axis A3, and the fourth axis A4, respectively. The angle sensors include the bucket angle sensor S3, a bucket rotation sensor S3R, an arm angle sensor S2, and a boom angle sensor S1. The angle sensors detect a bucket angle 63 and a bucket rotation angle θ3R which are rotation angles of the bucket 6 around the first axis A1 and the second axis A2, and an arm angle 62 and a boom angle θ1 which are rotation angles of the arm 5 and the boom 4 around the third axis A3 and the fourth axis A4. The operation device 26 includes the operation sensor 29 configured to detect the operation amounts of the boom 4, the arm 5, and the bucket 6 by the operator. The controller 30 controls the actuators and the rotator R based on the operation amount of the arm 5 detected by the operation sensor 29 of the operation device 26 and the bucket rotation angle θ3R detected by the bucket rotation sensor S3R when the construction surface GS is excavated.

With such a configuration, when the operator of the excavator 100 operates the operation device 26 to operate the arm 5, the boom 4 and the bucket 6 operate in accordance with the operation of the arm 5, and the excavation work of the construction surface GS can be performed. Further, the bucket 6 is automatically rotated by the rotator R during the excavation work of the construction surface GS, and the earth and sand ES can be made to overflow to one side of the bucket 6. Therefore, in the excavator 100 according to the present embodiment, the controller 30 automatically rotates the bucket 6 around the second axis A2 to execute machine control for supporting the operation of the operator, thereby improving the work efficiency E.

As described above, according to the present embodiment, it is possible to provide the excavator 100 capable of improving the work efficiency.

Another Embodiment

Next, an excavator according to another embodiment of the present disclosure will be described. The excavator 100 according to the present embodiment is different from the excavator 100 of the embodiment in that only the rotator motor R1 of the rotator R is set as the secondary element.

Specifically, the primary element setting part 3007 of the controller 30 illustrated in FIG. 3 sets, for example, each part of the attachment AT except for the rotator R as a primary element.

The primary command value generation part 3009 generates command values for operating the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the tilt actuator T4, for example, in accordance with the operation contents of the boom 4, the arm 5, and the bucket 6 by the operator acquired by the operation content acquisition part 3001. The primary command value generation part 3009 outputs the generated command value to the boom command generation part 3011, the arm command generation part 3012, the bucket command generation part 3013, and the bucket tilt command generation part 3013T.

The secondary command value generation part 3010 generates a command value for controlling the operation of the rotator R as a secondary element in accordance with the operation of the attachment AT set as a primary element by the primary element setting part 3007, for example. Specifically, the secondary command value generation part 3010 calculates the angular velocity of the rotation of the bucket 6 by the rotator R so that the angular velocity of the primary element and the angular velocity of the rotation of the bucket 6 by the rotator R as the secondary element satisfy a predetermined condition, based on the angular velocities of the boom 4, the arm 5, and the bucket 6 as the primary elements, the information on the target surface TS, and the current position of the claw tip of the bucket 6 as the control reference. The secondary command value generation part 3010 outputs the generated command value to the bucket rotation command generation part 3013R.

As a result, the operator of the excavator 100 can operate the boom 4, the arm 5, and the bucket 6, which are primary elements, and operate the rotator R in accordance with the operations of the boom 4, the arm 5, and the bucket 6, for example, by operating the operation device 26. Thus, as illustrated in FIG. 5, the excavator 100 according to the present embodiment can rotate the bucket 6 around the second axis A2 along the longitudinal direction D1 and cause the earth and sand ES to overflow to one side of the bucket 6 by operating the rotator R of the attachments AT in accordance with the operations of the boom 4, the arm 5, and the bucket 6 during excavation of the construction surface GS by the bucket 6 by the MC function.

Therefore, in the excavator 100 according to the present embodiment, it is possible to improve the work efficiency E at the time of excavating the construction surface GS, similarly to the excavator 100 according to the embodiment described above. Further, in the excavator 100 according to the present embodiment, the respective parts of the attachment AT except for the rotator R can be operated based on the operation of the operation device 26 by the operator. Therefore, when the construction surface GS is excavated, the attachment AT can be flexibly operated based on the operation of the operation device 26 by the operator according to the change in the situation.

Still Another Embodiment

Next, an excavator according to still another embodiment of the present disclosure will be described. In the above-described embodiments, the example in which a part of the configuration of the attachment AT except for the rotator R is operated based on the operation of the operation device 26 by the operator has been described. In contrast, the excavator 100 according to the present embodiment is different from the excavator 100 according to the above-described embodiments in that the excavator 100 according to the present embodiment autonomously operates to perform the excavation work of the construction surface GS without depending on the operation of the operator.

In the excavator 100 according to the present embodiment, the controller 30 generates a target trajectory of the claw tip of the bucket 6 based on the information on the target surface TS, and calculates a target position of the claw tip of the bucket 6 based on the target trajectory. The controller 30 calculates the angular velocity of each part of the attachment AT so that the angular velocity of each part of the attachment AT satisfies a predetermined condition. The controller 30 generates command values for operating the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the tilt actuator T4, and the rotator motor R1 in accordance with the calculated angular velocities. Then, the controller 30 generates a pilot pressure command value based on the deviation between the angular velocities of the boom 4 and the arm 5 and the angular velocities of the bucket 6 around the first axis A1, the second axis A2, and the fifth axis A5 and the calculated command value, and outputs the pilot pressure command value to the valves 31.

With such a configuration, in the excavator 100 according to the present embodiment, when the excavator 100 is autonomously operated to excavate the construction surface GS, the bucket 6 can be rotated around the second axis A2 along the longitudinal direction D1 to cause the earth and sand ES to overflow to one side of the bucket 6.

Therefore, in the excavator 100 according to the present embodiment, it is possible to improve the work efficiency E at the time of excavating the construction surface GS, similarly to the excavator 100 of the embodiment described above. Further, in the excavator 100 according to the present embodiment, each part of the attachment AT including the rotator R can be autonomously operated. Therefore, it is possible to reduce the burden on the operator when excavating the construction surface GS.

Further Another Embodiment

Next, a configuration example of an operation system SYS according to an embodiment of the present disclosure will be described with reference to FIG. 7. FIG. 7 is a schematic diagram illustrating a configuration example of the operation system SYS. As illustrated in FIG. 7, the operation system SYS includes an excavator 100 and a remote control room RC. Note that a detailed configuration of the excavator 100 is not illustrated in FIG. 7. This is because the excavator 100 illustrated in FIG. 7 has the same configuration as the excavator 100 illustrated in FIG. 1.

The excavator 100 and the remote control room RC are connected to each other so as to be able to transmit and receive data via a communication network NW. The excavator 100 and the remote control room RC may be connected to each other so as to be able to directly transmit and receive data between each other without the communication network NW. In the illustrated example, the excavator 100 transmits information on a work site to the remote control room RC. Thus, the remote operator RO in the remote control room RC can identify a situation of the work site based on the information from the excavator 100.

The excavator 100 is provided with a sensor capable of three dimensionally recognizing the position and shape of an object existing in the work site. For example, the excavator 100 is provided with a space recognition device. Therefore, the excavator 100 can transmit the result of three dimensionally measuring the work site to the remote control room RC.

The space recognition device is a device for recognizing a space around the excavator 100. In the illustrated example, the space recognition device is a LiDAR. The LiDAR measures, for example, a distance between the LiDAR and each of one million or more points within a monitoring range. The space recognition device may be any device that can measure the distance to an object. For example, the space recognition device may be a stereo camera, or may be a combination of the imaging device S6 and a distance measuring device such as a millimeter wave radar.

The number of excavators 100 included in the operation system SYS may be one or more. In a case where a plurality of excavators 100 are included, the remote operator RO of a specific excavator 100 can acquire information on the work site acquired by the specific excavator 100 and information on the work site acquired by one or more other excavators 100.

In the remote control room RC, a remote communication device CD2, a remote controller 40, a remote operation device 26E, an operation sensor 43, and a display device DIE are installed. In addition, an operation seat DS on which a remote operator RO who remotely operates the excavator 100 sits is installed in the remote control room RC.

The remote communication device CD2 is configured to communicate with the communication device CD mounted on the excavator 100.

The remote controller 40 is a computing device that executes various computations. In the present embodiment, the remote controller 40 is configured by a microcomputer including a CPU and a memory. The various functions of the remote controller 40 are implemented by the CPU executing the programs stored in the memory.

The display device DIE is a device capable of displaying various kinds of information. The display device DIE displays an image based on information transmitted from the excavator 100 so that the remote operator RO in the remote control room RC can visually recognize the surroundings of the excavator 100. In the illustrated example, the display device DIE is a liquid-crystal display that displays an image captured by the imaging device S6 mounted on the excavator 100. The display device DIE may be a display or a projector that implements naked-eye stereoscopic vision, or may be a virtual reality (VR) headset or the like.

The remote operation device 26E is provided with an operation sensor 43 for detecting the operation content of the remote operation device 26E. The operation sensor 43 is, for example, an inclination sensor that detects an inclination angle of the operation lever, an angle sensor that detects a slewing angle of the operation lever around a slewing axis, or the like. The operation sensor 43 may be configured by another sensor such as a pressure sensor, an electric current sensor, a voltage sensor, or a distance sensor. The operation sensor 43 outputs information on the detected operation content of the remote operation device 26E to the remote controller 40. The remote controller 40 generates an operation signal based on the received information and transmits the generated operation signal to the excavator 100. The operation sensor 43 may be configured to generate the operation signal. In this case, the operation sensor 43 may output the operation signal to the remote communication device CD2 without passing through the remote controller 40. With such a configuration, the remote operator RO can remotely operate the excavator 100 from the remote control room RC.

As described above, the excavator operation system SYS of the present embodiment includes the excavator 100, the remote operation device 26E, and the remote communication device CD2. The excavator 100 includes a lower traveling body 1, an upper slewing body 3 slewably provided on the lower traveling body 1, an attachment AT provided on the upper slewing body 3, and a communication device CD provided on the upper slewing body 3. The remote communication device CD2 includes the operation sensor 43 configured to detect an operation amount of the excavator 100 by the remote operator RO. The remote communication device CD2 transmits the operation amount detected by the operation sensor 43 of the remote operation device 26E to the communication device CD. The attachment AT of the excavator 100 includes the bucket 6 rotatable around the first axis A1 along the width direction Dw, and the rotator R configured to rotate the bucket 6 around the second axis A2 along the longitudinal direction D1 to cause the earth and sand ES to overflow to one side of the bucket 6 when the bucket 6 excavates the construction surface GS.

With such a configuration, according to the excavator operation system SYS of the present embodiment, it is possible to reduce the overlap width Wd by which the range of the second and subsequent excavation work overlaps the range of the previous excavation work, compared to a case where the earth and sand ES is caused to overflow to both sides of the bucket 6 when the excavator 100 excavates the construction surface GS. Thus, the number of times of the excavation work during the excavation of the construction surface GS can be reduced as compared to a case where the earth and sand ES is caused to overflow to both sides of the bucket 6 during the excavation of the construction surface GS by the excavator 100. Therefore, according to the excavator operation system SYS of the present embodiment, the work efficiency E can be improved.

The preferred embodiments of the present disclosure have been described above. However, the invention according to the present disclosure is not limited to the above-described embodiments. Various modifications, substitutions, and the like can be applied to the above-described embodiments without departing from the scope of the invention according to the present disclosure. Further, the features described with reference to the above-described embodiments may be appropriately combined as long as there is no technical contradiction.