CONTROL SYSTEM OF WORK MACHINE, WORK MACHINE, AND CONTROL METHOD OF WORK MACHINE

Description

FIELD

The present disclosure relates to a control system of a work machine, the work machine, and a control method of the work machine.

BACKGROUND

In a technical field related to a work machine, a technique of excavating an excavation object based on a target construction surface is known. As the technique of excavating the excavation object based on the target construction surface, a machine guidance technique of presenting a guidance image indicating a relative position between the target construction surface and a bucket of working equipment to an operator of the work machine, and a machine control technique of performing assist control of an operation of the operator so that the bucket of the working equipment moves along the target construction surface are known. Patent Literature 1 discloses an example of the machine control technique.

CITATION LIST

Patent Literature

Patent Literature 1: WO 2015/129930 A

SUMMARY

Technical Problem

A target construction surface may be defined by a plurality of design surfaces having mutually different gradients. For example, when a slope, a top of slope, and a toe of slope are formed in an excavation object, a target construction surface may be defined by a first design surface indicating a target shape of the slope, a second design surface connected to an uppermost portion of the first design surface, and a third design surface connected to a lowermost portion of the first design surface. The gradient of the first design surface and the gradient of the second design surface are different from each other. The top of slope is defined at a boundary between the first design surface and the second design surface. The gradient of the first design surface and the gradient of the third design surface are different from each other. The toe of slope is defined at a boundary between the first design surface and the third design surface. When a bucket is controlled to continuously move along both the second design surface and the first design surface to form the top of slope, and when the bucket passes through the boundary between the second design surface and the first design surface, there is a possibility that the bucket cannot completely follow the second design surface and the first design surface due to, for example, a control delay. As a result, there is a possibility that the top of slope is not constructed in a desired shape. Therefore, a technique in which an expansion surface having the same gradient as the gradient of the first design surface is created in a top-of-slope direction of the first design surface, and working equipment is controlled so that the bucket continuously moves along both the expansion surface and the first design surface is known. A process of controlling the working equipment so that the bucket continuously moves along both the expansion surface and the first design surface and a process of controlling the working equipment so that the bucket moves along the second design surface are separately performed, whereby the top of slope is constructed in a desired shape. However, when the expansion surface is formed not only in the top-of-slope direction of the first design surface but also in a toe-of-slope direction of the first design surface, and when the working equipment is controlled so that the bucket continuously moves along both the first design surface and the expansion surface, there is a possibility that the bucket digs the third design surface and the excavation object is not constructed in a desired shape.

An object of the present disclosure is to construct an excavation object into a desired shape.

Solution to Problem

In order to achieve an aspect of the present invention, a control system of a work machine, the control system comprises: a construction data storage unit that stores a plurality of design surfaces set as an excavation object of the work machine; an expansion surface creation unit that creates, in each of a top-of-slope direction and a toe-of-slope direction, an expansion surface obtained by expanding a target construction surface indicating a target shape of a slope of the excavation object designated from among the plurality of design surfaces; and a working equipment control unit that controls, when the expansion surface is created in each of the top-of-slope direction and the toe-of-slope direction, working equipment provided in the work machine based on the expansion surface in the top-of-slope direction and the target construction surface, without using the expansion surface in the toe-of-slope direction.

Advantageous Effects of Invention

According to the present disclosure, an excavation object is constructed in a desired shape.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a work machine according to an embodiment.

FIG. 2 is a schematic diagram illustrating the work machine according to the embodiment.

FIG. 3 is a diagram illustrating a cab of the work machine according to the embodiment.

FIG. 4 is a block diagram illustrating a control system of the work machine according to the embodiment.

FIG. 5 is a diagram illustrating a target construction surface and an expansion surface.

FIG. 6 is a diagram illustrating the target construction surface and the expansion surface.

FIG. 7 is a flowchart illustrating a control method of the work machine according to the embodiment.

FIG. 8 is a diagram illustrating an example of a display screen displayed on a display device according to the embodiment.

FIG. 9 is a diagram illustrating a process of a working equipment control unit according to the embodiment.

FIG. 10 is a block diagram illustrating a computer system according to the embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be appropriately combined with each other. In addition, some components may not be used.

Work Machine

FIG. 1 is a perspective view illustrating a work machine 1 according to an embodiment. FIG. 2 is a schematic diagram illustrating the work machine 1 according to the embodiment. FIG. 3 is a diagram illustrating a cab 2 of the work machine 1 according to the embodiment.

The work machine 1 is operated at a work site. In the embodiment, the work machine 1 is an excavator. In the following description, the work machine 1 is appropriately referred to as an excavator 1.

The excavator 1 includes a traveling body 3, a swing body 4, working equipment 5, a hydraulic cylinder 6, an operating device 7, an in-vehicle monitor 8, a position sensor 9, an inclination sensor 10, a posture sensor 11, and a control device 12.

As illustrated in FIG. 2, a three-dimensional site coordinate system (Xg, Yg, Zg) is defined at the work site. A three-dimensional vehicle body coordinate system (Xm, Ym, Zm) is defined in the swing body 4.

The site coordinate system is configured by an Xg axis extending from a site reference point Og defined at the work site to the north and south, a Yg axis extending from the site reference point Og to the east and the west, and a Zg axis extending vertically from the site reference point Og.

The vehicle body coordinate system is configured by an Xm axis extending in the forward-and-rearward direction of the swing body 4 from a representative point Om defined in the swing body 4, a Ym axis extending in the left-and-right direction of the swing body 4 from the representative point Om, and a Zm axis extending in the upward-and-downward direction of the swing body 4 from the representative point Om. With reference to the representative point Om of the swing body 4, the +Xm direction is the front side of the swing body 4, the −Xm direction is the rear side of the swing body 4, the +Ym direction is the left side of the swing body 4, the −Ym direction is the right side of the swing body 4, the +Zm direction is the upper side of the swing body 4, and the −Zm direction is the lower side of the swing body 4.

The traveling body 3 travels while supporting the swing body 4. The traveling body 3 includes a pair of crawler belts 3A. By the rotation of the crawler belts 3A, the traveling body 3 performs traveling movement. The traveling movement of the traveling body 3 includes forward movement and rearward movement. The excavator 1 can move within the work site by the traveling body 3.

The swing body 4 is supported by the traveling body 3. The swing body 4 is disposed above the traveling body 3. The swing body 4 performs swing movement around a swing axis RX while being supported by the traveling body 3. The swing axis RX is parallel to the Zm axis. The swing movement of the swing body 4 includes a left swing movement and a right swing movement. The cab 2 is provided in the swing body 4.

The working equipment 5 is supported by the swing body 4. The working equipment 5 performs work. In the embodiment, the work performed by the working equipment 5 includes excavation work of excavating an excavation object and loading work of loading an excavated object onto a loading object.

The working equipment 5 includes a boom 5A, an arm 5B, and a bucket 5C. The proximal end portion of the boom 5A is rotatably connected to a front portion of the swing body 4. The proximal end portion of the arm 5B is rotatably connected to the distal end portion of the boom 5A. The proximal end portion of the bucket 5C is rotatably connected to the distal end portion of the arm 5B.

The hydraulic cylinder 6 causes the working equipment 5 to move. The hydraulic cylinder 6 includes a boom cylinder 6A, an arm cylinder 6B, and a bucket cylinder 6C. The boom cylinder 6A causes the boom 5A to perform a raising movement and a lowering movement. The arm cylinder 6B causes the arm 5B to perform an excavation movement and a dumping movement. The bucket cylinder 6C causes the bucket 5C to perform the excavation movement and the dumping movement. The proximal end portion of the boom cylinder 6A is connected to the swing body 4. The distal end portion of the boom cylinder 6A is connected to the boom 5A. The proximal end portion of the arm cylinder 6B is connected to the boom 5A. The distal end portion of the arm cylinder 6B is connected to the arm 5B. The proximal end portion of the bucket cylinder 6C is connected to the arm 5B. The distal end portion of the bucket cylinder 6C is connected to the bucket 5C.

As illustrated in FIG. 3, the operating device 7 is disposed in the cab 2. The operating device 7 is operated to cause at least one of the traveling body 3, the swing body 4, and the working equipment 5 to move. The operating device 7 is operated by an operator in the cab 2. The operator can operate the operating device 7 while sitting on a driver seat 14 disposed in the cab 2.

The operating device 7 includes a left working lever 7A and a right working lever 7B operated for the movement of the swing body 4 and the working equipment 5, a left traveling lever 7C and a right traveling lever 7D operated for the movement of the traveling body 3, and a left foot pedal 7E and a right foot pedal 7F.

When the left working lever 7A is operated in the forward-and-rearward direction, the arm 5B performs the dumping movement or the excavation movement. When the left working lever 7A is operated in the left-and-right direction, the swing body 4 performs the left swing movement or the right swing movement. When the right working lever 7B is operated in the left-and-right direction, the bucket 5C performs the excavation movement or the dumping movement. When the right working lever 7B is operated in the forward-and-rearward direction, the boom 5A performs the lowering movement or the raising movement. Note that the swing body 4 may perform the left swing movement or the right swing movement when the left working lever 7A is operated in the forward-and-rearward direction, and the arm 5B may perform the dumping movement or the excavation movement when the left working lever 7A is operated in the left-and-right direction.

When the left traveling lever 7C is operated in the forward-and-rearward direction, the crawler belt 3A on the left side of the traveling body 3 performs the forward movement or the rearward movement. When the right traveling lever 7D is operated in the forward-and-rearward direction, the crawler belt 3A on the right side of the traveling body 3 performs the forward movement or the rearward movement.

The left foot pedal 7E is operated in conjunction with the left traveling lever 7C. The right foot pedal 7F is operated in conjunction with the right traveling lever 7D. The traveling body 3 may perform the forward movement or the rearward movement by operating the left foot pedal 7E and the right foot pedal 7F.

The in-vehicle monitor 8 is disposed in the cab 2. The in-vehicle monitor 8 is disposed on the right front side of the driver seat 14. The in-vehicle monitor 8 includes a display device 8A, an input device 8B, and an alarm device 8C.

The display device 8A displays prescribed display data. As the display device 8A, a flat panel display such as a liquid crystal display (LCD) or an organic electroluminescence display (OELD) is exemplified.

The input device 8B generates input data by being operated by the operator. Examples of the input device 8B include a button switch, a computer keyboard, and a touch panel.

The alarm device 8C outputs a prescribed alarm. In the embodiment, the alarm device 8C is a sound output device that outputs an alarm sound. Note that the alarm device 8C may be a light emitting device that outputs alarm light.

The position sensor 9 detects the position of the swing body 4 in the site coordinate system. The position sensor 9 detects the position of the swing body 4 in the site coordinate system using a global navigation satellite system (GNSS). The global navigation satellite system includes a global positioning system (GPS). The global navigation satellite system detects a position defined by coordinate data of latitude, longitude, and altitude. The position sensor 9 includes a GNSS receiver that receives GNSS radio waves from a GNSS satellite. The position sensor 9 is disposed in the swing body 4. In the embodiment, the position sensor 9 is disposed in a counterweight of the swing body 4.

The position sensor 9 includes a first position sensor 9A and a second position sensor 9B. The first position sensor 9A and the second position sensor 9B are disposed at different positions in the swing body 4. In the embodiment, the first position sensor 9A and the second position sensor 9B are disposed at intervals in the left-and-right direction in the swing body 4. The first position sensor 9A detects a first measured position indicating a position in which the first position sensor 9A is disposed. The second position sensor 9B detects a second measured position indicating a position in which the second position sensor 9B is disposed.

The inclination sensor 10 detects acceleration and angular velocity of the swing body 4. The inclination sensor 10 includes an inertial measurement unit (IMU). The inclination sensor 10 is disposed in the swing body 4. In the embodiment, the inclination sensor 10 is installed below the cab 2.

The posture sensor 11 detects the posture of the working equipment 5. The posture of the working equipment 5 includes an angle of the working equipment 5. The posture sensor 11 includes a first posture sensor 11A that detects an angle of the boom 5A relative to the swing body 4, a second posture sensor 11B that detects an angle of the arm 5B relative to the boom 5A, and a third posture sensor 11C that detects an angle of the bucket 5C relative to the arm 5B. The posture sensor 11 may be a stroke sensor that detects a stroke of the hydraulic cylinder 6 or a potentiometer that detects the angle of the working equipment 5.

Control System

FIG. 4 is a block diagram illustrating a control system 30 of the work machine 1 according to the embodiment. The excavator 1 includes the control system 30. The control system 30 includes the in-vehicle monitor 8, the position sensor 9, the inclination sensor 10, the posture sensor 11, and the control device 12. The control device 12 controls the excavator 1. The control device 12 includes a computer system.

The in-vehicle monitor 8 includes a controller 40. The controller 40 includes a construction data storage unit 15, an input data acquisition unit 18, an expansion surface creation unit 23, and a display control unit 25.

The control device 12 includes a vehicle body data storage unit 16, an operation data acquisition unit 17, a sensor data acquisition unit 19, a position/azimuth calculation unit 20, an inclination angle calculation unit 21, a working equipment position calculation unit 22, a toe of slope determination unit 24, a traveling control unit 26, a swing control unit 27, and a working equipment control unit 28.

The construction data storage unit 15 stores a plurality of design surfaces set at the work site. The plurality of design surfaces is set as an excavation object of the excavator 1 at the work site. The design surface is created by a computer system existing outside the excavator 1. The design surface is created in an external facility of the excavator 1, such as a design room. The design surface is a surface defined in the site coordinate system. A target construction surface indicating a target shape of the excavation object is defined by the plurality of design surfaces. The excavator 1 excavates the excavation object based on the target construction surface.

The vehicle body data storage unit 16 stores vehicle body data of the excavator 1. The vehicle body data of the excavator 1 includes dimensions of the working equipment 5. The dimensions of the working equipment 5 include a length of the boom 5A, a length of the arm 5B, and a length of the bucket 5C. In addition, the vehicle body data of the excavator 1 includes dimensions of the traveling body 3 and dimensions of the swing body 4.

The operation data acquisition unit 17 acquires operation data generated by operating the operating device 7.

The input data acquisition unit 18 acquires input data generated by operating the input device 8B.

The sensor data acquisition unit 19 acquires detection data of the position sensor 9, detection data of the inclination sensor 10, and detection data of the posture sensor 11.

The position/azimuth calculation unit 20 calculates a position and an azimuth angle of the swing body 4 in the site coordinate system based on the detection data of the position sensor 9. As described above, the position sensor 9 includes the GNSS receiver that receives GNSS radio waves. The position/azimuth calculation unit 20 calculates the position and the azimuth angle of the swing body 4 based on the GNSS radio waves. The azimuth angle of the swing body 4 is, for example, an azimuth angle of the swing body 4 based on the Xg axis.

The position/azimuth calculation unit 20 calculates the position of the swing body 4 based on at least one of the first measured position detected by the first position sensor 9A and the second measured position detected by the second position sensor 9B. The position/azimuth calculation unit 20 calculates the azimuth angle of the swing body 4 based on a relative position between the first measured position detected by the first position sensor 9A and the second measured position detected by the second position sensor 9B.

The inclination angle calculation unit 21 calculates an inclination angle of the swing body 4 based on the detection data of the inclination sensor 10. The inclination angle of the swing body 4 includes a roll angle and a pitch angle of the swing body 4. The roll angle refers to an inclination angle of the swing body 4 in an inclination direction around the Xg axis. The pitch angle refers to an inclination angle of the swing body 4 in an inclination direction around the Yg axis. The inclination angle calculation unit 21 calculates the roll angle and the pitch angle of the swing body 4 based on the detection data of the inclination sensor 10.

The working equipment position calculation unit 22 calculates a position of the working equipment 5 based on the position of the work machine 1 calculated by the position/azimuth calculation unit 20. In the embodiment, the working equipment position calculation unit 22 calculates the position of the working equipment 5 in the site coordinate system based on the vehicle body data of the excavator 1 stored in the vehicle body data storage unit 16, the position and azimuth angle of the swing body 4 calculated by the position/azimuth calculation unit 20, the inclination angle of the swing body 4 calculated by the inclination angle calculation unit 21, and the detection data of the posture sensor 11. The position of the working equipment 5 includes the position of the bucket 5C. The position of the bucket 5C includes the position of a blade edge 5D provided at a distal end portion of the bucket 5C.

The expansion surface creation unit 23 creates, in each of a top-of-slope direction and a toe-of-slope direction, an expansion surface obtained by expanding a target construction surface indicating a target shape of a slope of an excavation object designated from among the plurality of design surfaces.

The toe of slope determination unit 24 determines whether there is a toe of slope at a boundary between the target construction surface and an adjacent design surface connected to the target construction surface among the plurality of design surfaces based on a relative position between the adjacent design surface and the expansion surface.

The Display Control Unit 25 Controls the Display device 8A of the in-vehicle monitor 8. The display control unit 25 causes the display device 8A to display prescribed display data.

The traveling control unit 26 controls the traveling body 3 based on the operation data of the operating device 7 acquired by the operation data acquisition unit 17.

The swing control unit 27 controls the swing body 4 based on the operation data of the operating device 7 acquired by the operation data acquisition unit 17.

The working equipment control unit 28 controls the working equipment 5. Controlling the working equipment 5 includes controlling the hydraulic cylinder 6. The working equipment control unit 28 controls the working equipment 5 based on the operation data of the operating device 7 acquired by the operation data acquisition unit 17. In addition, the working equipment control unit 28 performs assist control of an operation of the operator so that the bucket 5C of the working equipment 5 moves along the target construction surface. The working equipment control unit 28 performs assist control on the working equipment 5 so that the blade edge 5D of the bucket 5C calculated by the working equipment position calculation unit 22 follows the target construction surface designated by the operator.

Target Construction Surface and Expansion Surface

Each of FIGS. 5 and 6 is a diagram illustrating a target construction surface 150 and an expansion surface 13. As illustrated in FIGS. 5 and 6, when a slope 50, a top of slope 51, and a toe of slope 52 are formed in an excavation object, the target construction surface 150 is defined by a first design surface 15B indicating the target shape of the slope 50, a second design surface 15A connected to the uppermost portion of the first design surface 15B, and a third design surface 15C connected to the lowermost portion of the first design surface 15B. Each of the first design surface 15B, the second design surface 15A, and the third design surface 15C is a plane. The gradient of the first design surface 15B and the gradient of the second design surface 15A are different from each other. The top of slope 51 is defined at a boundary between the first design surface 15B and the second design surface 15A. The gradient of the first design surface 15B and the gradient of the third design surface 15C are different from each other. The toe of slope 52 is defined at a boundary between the first design surface 15B and the third design surface 15C.

When the bucket 5C is controlled to continuously move along both the second design surface 15A and the first design surface 15B to form the top of slope 51 with the bucket 5C, and when the bucket 5C passes through the boundary between the second design surface 15A and the first design surface 15B, there is a possibility that the bucket 5C cannot completely follow the second design surface 15A and the first design surface 15B due to, for example, a control delay. As a result, there is a possibility that the top of slope 51 is not constructed in a desired shape.

Therefore, the expansion surface creation unit 23 creates the expansion surface 13 having the same gradient as the gradient of the design surface. As illustrated in FIG. 5, when assist control of an operation of an operator is performed so that the blade edge 5D of the bucket 5C moves along the second design surface 15A, the expansion surface creation unit 23 creates the expansion surface 13 in each of an excavation start direction and an excavation end direction of the second design surface 15A.

Specifically, as illustrated in FIG. 5, a start side expansion surface 13A is created in the excavation start direction of the second design surface 15A, and an end side expansion surface 13B is created in the excavation end direction of the second design surface 15A. The gradient of the start side expansion surface 13A, the gradient of the second design surface 15A, and the gradient of the end side expansion surface 13B are the same. The start side expansion surface 13A is created to be connected to an excavation start side end portion of the second design surface 15A. The start side expansion surface 13A is created to be expanded in the excavation start direction from the excavation start side end portion of the second design surface 15A. The end side expansion surface 13B is created to be connected to an excavation end side end portion of the second design surface 15A. The end side expansion surface 13B is created to be expanded in the excavation end direction from the excavation end side end portion of the second design surface 15A. Assist control of the working equipment 5 is performed so that the blade edge 5D of the bucket 5C continuously moves along the start side expansion surface 13A, the second design surface 15A, and the end side expansion surface 13B. As a result, an upper surface of the excavation object configuring a part of the top of slope 51 is formed.

A process of forming the upper surface of the excavation object is performed separately from a process of forming the slope 50 of the excavation object. For example, after the upper surface of the excavation object is formed, the process of forming the slope 50 of the excavation object is started. Note that the slope 50 of the excavation object may be formed before the upper surface of the excavation object is formed.

As illustrated in FIG. 6, when assist control of an operation of an operator is performed so that the blade edge 5D of the bucket 5C moves along the first design surface 15B, the expansion surface creation unit 23 creates the expansion surface 13 in each of the top-of-slope direction and the toe-of-slope direction of the first design surface 15B. When the slope 50 is formed, the top of slope side is the excavation start side, and the toe of slope side is the excavation end side. Specifically, as illustrated in FIG. 6, a top of slope side expansion surface 13C is formed in the top-of-slope direction of the first design surface 15B, and a toe of slope side expansion surface 13D is formed in the toe-of-slope direction of the first design surface 15B. The gradient of the top of slope side expansion surface 13C, the gradient of the first design surface 15B, and the gradient of the toe of slope side expansion surface 13D are the same. The top of slope side expansion surface 13C is created to be connected to the top of slope side end portion of the first design surface 15B. The top of slope side expansion surface 13C is created to be expanded in the top-of-slope direction from the top of slope side end portion of the first design surface 15B. The toe of slope side expansion surface 13D is created to be connected to the toe of slope side end portion of the first design surface 15B. The toe of slope side expansion surface 13D is created to be expanded in the toe-of-slope direction from the toe of slope side end portion of the first design surface 15B. Assist control of the working equipment 5 is performed so that the blade edge 5D of the bucket 5C continuously moves along the top of slope side expansion surface 13C and the first design surface 15B. By forming the upper surface of the excavation object and an upper portion of the slope 50, the top of slope 51 is formed.

The process of controlling the working equipment 5 so that the bucket 5C continuously moves along the start side expansion surface 13A, the second design surface 15A, and the end side expansion surface 13B, and the process of controlling the working equipment 5 so that the bucket 5C continuously moves along the top of slope side expansion surface 13C and the first design surface 15B are separately performed, whereby the top of slope 51 is constructed in a desired shape.

When forming the slope 50, assist control of the working equipment 5 is performed so that the blade edge 5D of the bucket 5C continuously moves along the top of slope side expansion surface 13C, the first design surface 15B, and the toe of slope side expansion surface 13D, whereby the slope 50 may be appropriately formed. However, when the toe of slope side expansion surface 13D is created, and when the working equipment 5 is controlled so that the bucket 5C continuously moves along both the first design surface 15B and the toe of slope side expansion surface 13D, there is a possibility that the bucket 5C digs the third design surface 15C and the excavation object is not constructed in a desired shape.

Therefore, in the embodiment, when the expansion surface creation unit 23 creates, in each of the top-of-slope direction and the toe-of-slope direction, the expansion surface 13 obtained by expanding the first design surface 15B, that is the target construction surface 150 indicating the target shape of the slope 50 of the excavation object, the working equipment control unit 28 performs assist control of the working equipment 5 based on the top of slope side expansion surface 13C, that is the expansion surface 13 in the top-of-slope direction, and the first design surface 15B, without using the toe of slope side expansion surface 13D, that is the expansion surface 13 in the toe-of-slope direction. That is, when each of the top of slope side expansion surface 13C and the toe of slope side expansion surface 13D is created by the expansion surface creation unit 23, the working equipment control unit 28 invalidates the toe of slope side expansion surface 13D, and performs assist control of the working equipment 5 so that the blade edge 5D of the bucket 5C moves only along the top of slope side expansion surface 13C and the first design surface 15B.

Control Method

FIG. 7 is a flowchart illustrating a control method of the excavator 1 according to the embodiment. The construction data storage unit 15 stores a plurality of design surfaces. An operator of the excavator 1 operates the input device 8B and designates the target construction surface 150 indicating the target shape of the slope 50 of the excavation object from among the plurality of design surfaces.

FIG. 8 is a diagram illustrating an example of a display screen displayed on the display device 8A according to the embodiment. The construction data storage unit 15 stores at least the first design surface 15B, the second design surface 15A, and the third design surface 15C. The operator operates the input device 8B and designates the first design surface 15B as the target construction surface 150 indicating the target shape of the slope 50 from among the first design surface 15B, the second design surface 15A, and the third design surface 15C.

The input data acquisition unit 18 acquires the input data from the input device 8B. The input data acquisition unit 18 designates the first design surface 15B as the target construction surface 150 indicating the target shape of the slope 50 from among the first design surface 15B, the second design surface 15A, and the third design surface 15C based on the input data from the input device 8B (Step S1).

The expansion surface creation unit 23 creates the expansion surface 13 based on the first design surface 15B designated as the target construction surface 150. The expansion surface creation unit 23 creates the expansion surface 13 obtained by expanding the first design surface 15B in each of the top-of-slope direction and the toe-of-slope direction. As described with reference to FIG. 6, the expansion surface creation unit 23 creates the top of slope side expansion surface 13C and the toe of slope side expansion surface 13D (Step S2).

The toe of slope determination unit 24 determines whether there is a toe of slope at a boundary between the first design surface 15B and an adjacent design surface connected to the first design surface 15B that is the target construction surface 150 based on a relative position between the adjacent design surface and the expansion surface 13 (Step S3).

The toe of slope determination unit 24 determines whether the adjacent design surface is present at a location higher than the expansion surface 13 at the same point in a horizontal direction. When determining that the adjacent design surface is present at the location higher than the expansion surface 13 at the same point in the horizontal direction, the toe of slope determination unit 24 determines that the toe of slope is present at the boundary between the first design surface 15B and the adjacent design surface.

In the embodiment, the adjacent design surface connected to the first design surface 15B includes the second design surface 15A connected to the uppermost portion of the first design surface 15B and the third design surface 15C connected to the lowermost portion of the first design surface 15B. In the horizontal direction, the position of the second design surface 15A coincides with the position of at least a part of the top of slope side expansion surface 13C. In the horizontal direction, the position of the third design surface 15C coincides with the position of at least a part of the toe of slope side expansion surface 13D. The toe of slope determination unit 24 determines whether the second design surface 15A is present at a position higher than the top of slope side expansion surface 13C at the same point in the horizontal direction. The toe of slope determination unit 24 determines whether the third design surface 15C is present at a position higher than the toe of slope side expansion surface 13D at the same point in the horizontal direction.

As illustrated in FIGS. 6 and 8, the second design surface 15A is present at a position lower than the top of slope side expansion surface 13C at the same point in the horizontal direction. The third design surface 15C is present at a position higher than the toe of slope side expansion surface 13D at the same point in the horizontal direction. Therefore, the toe of slope determination unit 24 determines that there is no toe of slope at the boundary between the first design surface 15B and the second design surface 15A. The toe of slope determination unit 24 determines that a toe of slope is present at the boundary between the first design surface 15B and the third design surface 15C.

In Step S3, when it is determined that the toe of slope is present at the boundary between the first design surface 15B and the third design surface 15C (Step S3: Yes), the working equipment control unit 28 controls the working equipment 5 based on the top of slope side expansion surface 13C that is the expansion surface 13 in the top-of-slope direction, the first design surface 15B that is the target construction surface, and the third design surface 15C that is the adjacent design surface determined to have the toe of slope, without using the toe of slope side expansion surface 13D that is the expansion surface 13 in the toe-of-slope direction. That is, the working equipment control unit 28 invalidates the toe of slope side expansion surface 13D, and performs assist control of the working equipment 5 so that the blade edge 5D of the bucket 5C follows each of the top of slope side expansion surface 13C, the first design surface 15B, and the third design surface 15C (Step S4).

In step S3, when determining that there is no toe of slope at the boundary between the first design surface 15B and the third design surface 15C (Step S3: No), the working equipment control unit 28 controls the working equipment 5 based on the top of slope side expansion surface 13C and the first design surface 15B using the toe of slope side expansion surface 13D. That is, the working equipment control unit 28 validates the toe of slope side expansion surface 13D, and performs assist control of the working equipment 5 so that the blade edge 5D of the bucket 5C follows each of the top of slope side expansion surface 13C, the first design surface 15B, and the top of slope side expansion surface 13C (Step S5).

FIG. 9 is a diagram illustrating a process of the working equipment control unit 28 according to the embodiment. As illustrated in [before correction] of FIG. 9, when the toe of slope side expansion surface 13D is validated, and when the slope 50 is formed, assist control of the working equipment 5 is performed so that the blade edge 5D of the bucket 5C follows a target construction surface RT including the top of slope side expansion surface 13C, the first design surface 15B, and the toe of slope side expansion surface 13D. Here, there is a possibility that the bucket 5C digs the third design surface 15C and the excavation object is not constructed in a desired shape.

In the embodiment, as illustrated in [after correction] of FIG. 9, the working equipment control unit 28 invalidates the toe of slope side expansion surface 13D, and performs assist control of the working equipment 5 so that the blade edge 5D of the bucket 5C follows the target construction surface RT after correction including the top of slope side expansion surface 13C, the first design surface 15B, and the third design surface 15C. As a result, the excavation object is constructed in a desired shape.

Computer System

FIG. 10 is a block diagram illustrating a computer system 1000 according to the embodiment. The control device 12 described above includes the computer system 1000. The computer system 1000 includes a processor 1001 such as a central processing unit (CPU), a main memory 1002 including a nonvolatile memory such as a read only memory (ROM) and a volatile memory such as a random access memory (RAM), a storage 1003, and an interface 1004 including an input/output circuit. The function of the control device 12 described above is stored in the storage 1003 as a computer program. The processor 1001 reads the computer program from the storage 1003, loads the computer program in the main memory 1002, and executes the above-described processing according to the program. Note that the computer program may be distributed to the computer system 1000 via a network.

According to the above-described embodiment, the computer program or the computer system 1000 can execute: storing a plurality of design surfaces set as an excavation object of the excavator 1; creating, in each of the top-of-slope direction and the toe-of-slope direction, the expansion surface 13 obtained by expanding the first design surface 15B, that is a target construction surface indicating a target shape of the slope 50 of an excavation object designated from among the plurality of design surfaces; and controlling, when the expansion surface 13 is created in each of the top-of-slope direction and the toe-of-slope direction, the working equipment 5 provided in the excavator 1 based on the top of slope side expansion surface 13C, that is the expansion surface 13 in the top-of-slope direction, and the first design surface 15B, without using the toe of slope side expansion surface 13D, that is the expansion surface 13 in the toe-of-slope direction.

Effects

As described above, the control system 30 of the excavator 1 according to the embodiment includes: the construction data storage unit 15 that stores a plurality of design surfaces set as an excavation object of the excavator 1; the expansion surface creation unit 23 that creates, in each of the top-of-slope direction and the toe-of-slope direction, the expansion surface 13 obtained by expanding the first design surface 15B, that is a target construction surface indicating a target shape of the slope 50 of an excavation object designated from among the plurality of design surfaces; and the working equipment control unit 28 that controls, when the expansion surface 13 is created in each of the top-of-slope direction and the toe-of-slope direction, the working equipment 5 provided in the excavator 1 based on the top of slope side expansion surface 13C, that is the expansion surface 13 in the top-of-slope direction, and the first design surface 15B, without using the toe of slope side expansion surface 13D, that is the expansion surface 13 in the toe-of-slope direction.

In the embodiment, when forming the slope 50, and when the top of slope side expansion surface 13C and the toe of slope side expansion surface 13D are created for the first design surface 15B, that is the target construction surface of the slope 50, when assist control of the working equipment 5 is performed so that the bucket 5C continuously moves along the top of slope side expansion surface 13C, the first design surface 15B, and the toe of slope side expansion surface 13D, there is a possibility that the bucket 5C digs the third design surface 15C and the excavation object is not constructed in a desired shape. In the embodiment, when each of the top of slope side expansion surface 13C and the toe of slope side expansion surface 13D is created, assist control of the working equipment 5 is performed based on the top of slope side expansion surface 13C and the first design surface 15B without using the toe of slope side expansion surface 13D. Assist control of the working equipment 5 is performed so that the bucket 5C continuously moves along the top of slope side expansion surface 13C, the first design surface 15B, and the third design surface 15C, thereby suppressing the third design surface 15C from being dug. Therefore, the excavation object is constructed in a desired shape.

Other Embodiments

In the above-described embodiment, when the toe of slope determination unit 24 determines that the toe of slope is present, the working equipment control unit 28 performs assist control of the working equipment 5 so that the blade edge 5D of the bucket 5C follows the top of slope side expansion surface 13C, the first design surface 15B, and the third design surface 15C. Based on the input data from the input device 8B, the working equipment control unit 28 may perform assist control of the working equipment 5 based on the top of slope side expansion surface 13C, the first design surface 15B, and the third design surface 15C connected to the lowermost portion of the first design surface 15B among the plurality of design surfaces, without using the toe of slope side expansion surface 13D. That is, the target construction surface RT [after correction] in FIG. 9 may be designated by the operator. While confirming the target construction surface RT [before correction] in FIG. 9 displayed on the display device 8A, the operator can designate the target construction surface RT including the top of slope side expansion surface 13C, the first design surface 15B, and the third design surface 15C to be the target construction surface RT [after correction] in FIG. 9. For example, the operator can designate the target construction surface RT so that the working equipment 5 is assist-controlled using the third design surface 15C instead of using the toe of slope side expansion surface 13D.

In the above-described embodiment, each of the construction data storage unit 15, the vehicle body data storage unit 16, the operation data acquisition unit 17, the input data acquisition unit 18, the sensor data acquisition unit 19, the position/azimuth calculation unit 20, the inclination angle calculation unit 21, the working equipment position calculation unit 22, the expansion surface creation unit 23, the toe of slope determination unit 24, the display control unit 25, the traveling control unit 26, the swing control unit 27, and the working equipment control unit 28 may be configured by separate hardware.

In the above-described embodiment, the work machine 1 is an excavator including the traveling body 3 and the swing body 4. The work machine 1 may not include the traveling body 3 and the swing body 4. The work machine 1 only needs to have a working equipment, and may be, for example, a bulldozer or a wheel loader.

REFERENCE SIGNS LIST

• • 1 EXCAVATOR (WORK MACHINE)
  • 2 CAB
  • 3 TRAVELING BODY
  • 3A CRAWLER BELT
  • 4 SWING BODY
  • 5 WORKING EQUIPMENT
  • 5A BOOM
  • 5B ARM
  • 5C BUCKET
  • 5D BLADE EDGE
  • 6 HYDRAULIC CYLINDER
  • 6A BOOM CYLINDER
  • 6B ARM CYLINDER
  • 6C BUCKET CYLINDER
  • 7 OPERATING DEVICE
  • 7A LEFT WORKING LEVER
  • 7B RIGHT WORKING LEVER
  • 7C LEFT TRAVELING LEVER
  • 7D RIGHT TRAVELING LEVER
  • 7E LEFT FOOT PEDAL
  • 7F RIGHT FOOT PEDAL
  • 8 IN-VEHICLE MONITOR
  • 8A DISPLAY DEVICE
  • 8B INPUT DEVICE
  • 8C ALARM DEVICE
  • 9 POSITION SENSOR
  • 9A FIRST POSITION SENSOR
  • 9B SECOND POSITION SENSOR
  • 10 INCLINATION SENSOR
  • 11 POSTURE SENSOR
  • 11A FIRST POSTURE SENSOR
  • 11B SECOND POSTURE SENSOR
  • 11C THIRD POSTURE SENSOR
  • 12 CONTROL DEVICE
  • 13 EXPANSION SURFACE
  • 13A START SIDE EXPANSION SURFACE
  • 13B END SIDE EXPANSION SURFACE
  • 13C TOP OF SLOPE SIDE EXPANSION SURFACE
  • 13D TOE OF SLOPE SIDE EXPANSION SURFACE
  • 14 DRIVER SEAT
  • 15 CONSTRUCTION DATA STORAGE UNIT
  • 15A SECOND DESIGN SURFACE
  • 15B FIRST DESIGN SURFACE
  • 15C THIRD DESIGN SURFACE
  • 16 VEHICLE BODY DATA STORAGE UNIT
  • 17 OPERATION DATA ACQUISITION UNIT
  • 18 INPUT DATA ACQUISITION UNIT
  • 19 SENSOR DATA ACQUISITION UNIT
  • 20 POSITION/AZIMUTH CALCULATION UNIT
  • 21 INCLINATION ANGLE CALCULATION UNIT
  • 22 WORKING EQUIPMENT POSITION CALCULATION UNIT
  • 23 EXPANSION SURFACE CREATION UNIT
  • 24 TOE OF SLOPE DETERMINATION UNIT
  • 25 DISPLAY CONTROL UNIT
  • 26 TRAVELING CONTROL UNIT
  • 27 SWING CONTROL UNIT
  • 28 WORKING EQUIPMENT CONTROL UNIT
  • 30 CONTROL SYSTEM
  • 50 SLOPE
  • 51 TOP OF SLOPE
  • 52 TOE OF SLOPE
  • 150 TARGET CONSTRUCTION SURFACE
  • 1000 COMPUTER SYSTEM
  • 1001 PROCESSOR
  • 1002 MAIN MEMORY
  • 1003 STORAGE
  • 1004 INTERFACE
  • Og SITE REFERENCE POINT
  • Om REPRESENTATIVE POINT
  • RX SWING AXIS