Shovel and shovel control system

Abstract

To improve work efficiency. [Solution] An excavator according to one embodiment comprises a lower traveling body, an upper rotating body mounted on the lower traveling body so as to be rotatable, an attachment having a boom, an arm, and an end attachment, a control device that autonomously operates the attachment according to a target trajectory, and a spatial recognition device that acquires information indicating the shape of objects around the excavator. The control device calculates a predicted excavation reaction force estimated to occur in the attachment while excavating according to the target trajectory, based on the shape of the soil around the excavator and the target trajectory, which are included in the information acquired by the spatial recognition device, and operates the attachment in a direction in which the excavation reaction force decreases based on the predicted excavation reaction force.

Description

Technical Field

[0001] The present invention relates to an excavator and a control system for an excavator.

Background Art

[0002] Conventionally, when performing an excavation operation with an attachment of an excavator, if the earth and sand to be excavated are harder than expected, the excavator may reach the limit of the torque that can be output, and the operation of the attachment may stop. Therefore, a technique has been proposed to suppress the stop of the operation of the attachment by performing a boom raising operation when the excavation reaction force generated during the excavation operation by the attachment is above a threshold value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the excavator described in Patent Document 1, when the excavation reaction force is above the threshold value, the bucket is deflected upward in the previous traveling direction, so there is a possibility that the excavation operation ends and the work efficiency decreases.

[0005] In view of the above, by operating the attachment in a direction in which the excavation reaction force decreases based on the predicted excavation reaction force estimated to occur in the attachment while excavating according to the target trajectory, the end of excavation is suppressed and an improvement in work efficiency is realized.

Means for Solving the Problems

[0006] An excavator according to one aspect of the present invention comprises a lower traveling body, an upper rotating body mounted on the lower traveling body so as to be rotatable, an attachment having a boom, an arm, and an end attachment, a control device for autonomously operating the attachment according to a target trajectory, and a spatial recognition device for acquiring information indicating the shape of objects around the excavator. The control device calculates a predicted excavation reaction force estimated to occur in the attachment while excavating according to the target trajectory, based on the shape of the soil around the excavator and the target trajectory, which are included in the information acquired by the spatial recognition device, and operates the attachment in a direction that reduces the excavation reaction force based on the predicted excavation reaction force. [Effects of the Invention]

[0007] According to one aspect of the present invention, by operating the attachment in a direction that reduces the excavation reaction force, the termination of excavation is suppressed, thereby improving work efficiency. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing an excavator according to the first embodiment. [Figure 2] This figure shows an example of the configuration of the drive control system for an excavator according to the first embodiment. [Figure 3] This is a conceptual diagram illustrating the method for calculating the excavation reaction force using a controller according to the first embodiment. [Figure 4] This is a functional block diagram showing an example of the functional configuration of the controller for the shovel according to the first embodiment. [Figure 5] This figure shows an example of a target trajectory acquired by the target trajectory acquisition unit according to the first embodiment. [Figure 6] This graph shows the excavation reaction force generated in the attachment during excavation by a shovel according to the first embodiment. [Figure 7] This figure illustrates the trajectory of a bucket provided on a shovel according to the first embodiment. [Figure 8]This is a flowchart showing the processing procedure for autonomous excavation operation by the attachment in the controller according to the first embodiment. [Figure 9] This is a schematic diagram showing an example configuration of a remote control system according to the second embodiment. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are illustrative and do not limit the invention. Not all features and combinations thereof in the embodiments of this disclosure are necessarily essential to the invention. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and redundant descriptions may be omitted.

[0010] The shovel 100 according to the embodiment of this disclosure is an example of a working machine. The shovel 100 according to this embodiment is an excavator equipped with a bucket 6 as an end attachment, but it may be an applied machine with other configurations.

[0011] (First embodiment) First, with reference to Figure 1, an overview of the shovel 100 according to this embodiment will be described. Figure 1 is a side view of the shovel 100 as a work machine according to the first embodiment.

[0012] In Figure 1, +X represents one direction of the X-axis in the three-dimensional Cartesian coordinate system, and (not shown) -X represents the other direction of the X-axis. +Y represents one direction of the Y-axis in the three-dimensional Cartesian coordinate system, and (not shown) -Y represents the other direction of the Y-axis. +Z represents one direction of the Z-axis in the three-dimensional Cartesian coordinate system, and (not shown) -Z represents the other direction of the Z-axis. In Figure 1, the +X side of shovel 100 corresponds to the front side of shovel 100, and the -X side of shovel 100 corresponds to the rear side of shovel 100. Also, the +Y side of shovel 100 corresponds to the left side of shovel 100, and the -Y side of shovel 100 corresponds to the right side of shovel 100. Furthermore, the +Z side of shovel 100 corresponds to the top side of shovel 100, and the -Z side of shovel 100 corresponds to the bottom side of shovel 100. The same applies to other figures.

[0013] The shovel 100 comprises a lower traveling body 1, an upper rotating body 3 mounted on the lower traveling body 1 so as to be rotatable via a slewing mechanism 2, an attachment AT for performing various tasks, and a driver's cab 10. The driver's cab 10 is also called a cabin or cab. The front side of the shovel 100 (upper rotating body 3) corresponds to the side on which the attachment AT is attached to the upper rotating body 3 when the shovel 100 is viewed from directly above along the rotation axis of the upper rotating body 3. The left, right, and rear sides of the shovel 100 (upper rotating body 3) correspond to the left, right, and rear sides as seen from the perspective of an operator seated in the driver's seat inside the driver's cab 10, respectively.

[0014] The lower traveling body 1 includes, for example, a pair of left and right crawlers 1C. Specifically, the crawlers 1C include a left crawler and a right crawler. The left crawler is driven by a left traveling hydraulic motor 2ML (see FIG. 2), and the right crawler is driven by a right traveling hydraulic motor 2MR (see FIG. 2). The left traveling hydraulic motor 2ML is a traveling drive unit that drives the left crawler as a driven part and can rotate the left crawler. The right traveling hydraulic motor 2MR is a traveling drive unit that drives the right crawler as a driven part and can rotate the right crawler. Note that the traveling drive unit may be an electric motor. The excavator 100 according to the present embodiment is not limited to a crawler-type excavator having crawlers 1C and may be a wheel-type excavator.

[0015] A boom 4 is rotatably attached to the center of the front part of the upper slewing body 3. An arm 5 is rotatably attached to the tip of the boom 4, and a bucket 6 is rotatably attached to the tip of the arm 5. In the illustrated example, the boom 4, the arm 5, and the bucket 6 constitute an excavation attachment, which is an example of an attachment AT. The boom 4, the arm 5, and the bucket 6 are driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, respectively.

[0016] The bucket 6 is an example of a working tool (end attachment). The bucket 6 is used, for example, in excavation work or the like. At the tip of the arm 5, other working tools may be attached instead of the bucket 6 according to the work content or the like. The other working tools may be, for example, other types of buckets such as a large bucket, a slope bucket, or a dredging bucket. Further, the other working tools may be working tools other than buckets such as a stirrer, a breaker, a grapple, or a lifting magnet. The excavation attachment may be provided with a bucket tilt mechanism.

[0017] [[ID=

[0018] Note that all or part of the driven parts such as the lower traveling body 1, the upper revolving body 3, the boom 4, the arm 5, and the bucket 6 of the excavator 100 may be electrically driven. That is, the excavator 100 may be a hybrid excavator or an electric excavator in which all or part of the driven parts are driven by electric actuators.

[0019] The imaging device S6 is provided on the upper revolving body 3, 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.

[0020] The front camera S6F is a camera that images the front of the excavator 100 and is attached outside the cab 10, such as on the roof of the cab 10 or the side surface of the boom 4. The left camera S6L is a camera that images the left side of the excavator 100, the right camera S6R is a camera that images the right side of the excavator 100, and the rear camera S6B is a camera that images the rear 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 equipped with an image pickup element such as a CCD or a CMOS, and the information of the captured image is taken into the controller 30. Further, the image captured by the imaging device S6 may be output to a display device D1 (see FIG. 2).

[0021] In the illustrated example, the front camera S6F is attached to the roof of the cab 10, the left camera S6L is attached to the left end of the upper surface of the upper revolving body 3, the right camera S6R is attached to the right end of the upper surface of the upper revolving body 3, and the rear camera S6B is attached to the rear end of the upper surface of the upper revolving body 3.

[0022] The spatial recognition device S10 is configured to recognize the state of the space around the shovel 100. The spatial recognition device S10 includes a rear spatial recognition device S10B for detecting the space behind the shovel 100, a left spatial recognition device S10L for detecting the space to the left of the shovel 100, a right spatial recognition device S10R for detecting the space to the right of the shovel 100, and a front spatial recognition device S10F for detecting the space in front of the shovel 100.

[0023] The spatial recognition device S10 may use a LiDAR to detect objects present around the shovel 100. The LiDAR measures, for example, the distance between the LiDAR and more than one million points within the monitoring range. This embodiment is not limited to the use of a LiDAR; any spatial recognition device capable of measuring the distance to an object is acceptable. For example, a stereo camera may be used, as well as a distance image camera or a distance measuring device such as a millimeter-wave radar. If a millimeter-wave radar or the like is used as the spatial recognition device S10, the spatial recognition device S10 may emit a large number of signals (such as laser light) toward the object and receive the reflected signals to derive the distance and direction of the object from the reflected signals.

[0024] The rear spatial recognition device S10B is mounted on the rear end of the upper surface of the upper rotating body 3. The left spatial recognition device S10L is mounted on the left end of the upper surface of the upper rotating body 3. The right spatial recognition device S10R is mounted on the right end of the upper surface of the upper rotating body 3. The forward spatial recognition device S10F is mounted on the front end of the upper surface of the driver's cab 10.

[0025] The spatial recognition device S10 may be configured to detect a predetermined object within a predetermined area set around the shovel 100. For example, the spatial recognition device S10 may have a person detection function configured to detect people while distinguishing between people and non-person objects. Furthermore, the spatial recognition device S10 may be configured to detect the ground and may also have a function to detect the shape of soil and sand present on the ground.

[0026] The controller 30 is an example of a control device and consists of a computer including, for example, a CPU, a volatile memory device, a non-volatile memory device, and various input / output interfaces. The controller 30 implements various functions, for example, by reading a program from the non-volatile memory device, loading it into the volatile memory device, and having the CPU execute it. In the illustrated example, the controller 30 is configured to implement various functions and control the shovel 100. These functions include, for example, a machine guidance function that guides the operator in manually operating the shovel 100. The functions may also include a contact avoidance function that automatically or autonomously operates or stops the shovel 100 to avoid contact between the shovel 100 and objects within the monitoring range around the shovel 100.

[0027] The boom angle sensor S1 detects the rotation angle of the boom 4. In this embodiment, the boom angle sensor S1 is an acceleration sensor that can detect the rotation angle of the boom 4 relative to the upper slewing body 3 (hereinafter referred to as "boom angle") which changes per unit time. The boom angle sensor S1 can detect the angular velocity of the boom 4, which indicates the change in boom angle, and the angular acceleration of the boom 4, which indicates the rate of said change. The boom angle is, for example, at its minimum when the boom 4 is at its lowest position, and increases as the boom 4 is raised.

[0028] The arm angle sensor S2 detects the rotation angle of the arm 5. In this embodiment, the arm angle sensor S2 is an acceleration sensor and can detect the rotation angle of the arm 5 relative to the boom 4 (hereinafter referred to as "arm angle"). The arm angle sensor S2 can detect the angular velocity of the arm 5, which indicates the change in the arm angle, and the angular acceleration of the arm 5, which indicates the rate of change. The arm angle is, for example, at its minimum when the arm 5 is closed to its shortest extent, and increases as the arm 5 is opened.

[0029] The bucket angle sensor S3 detects the rotation angle of the bucket 6. In this embodiment, the bucket angle sensor S3 is an acceleration sensor and can detect the rotation angle of the bucket 6 relative to the arm 5 (hereinafter referred to as "bucket angle"). The bucket angle sensor S3 can detect the angular velocity of the bucket 6, which indicates the change in bucket angle, and the angular acceleration of the bucket 6, which indicates the rate of change. The bucket angle is, for example, at its minimum when the bucket 6 is fully closed, and increases as the bucket 6 is opened.

[0030] The boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3 can be any sensor capable of acquiring the attitude of the attachment (an example of an attitude sensor), and may be an IMU (Inertial Measurement Unit), a 6-axis sensor, a potentiometer using a variable resistor, a stroke sensor that detects the stroke amount of the corresponding hydraulic cylinder, a rotary encoder that detects the rotation angle around the connecting pin, a gyro sensor, or a combination of an acceleration sensor and a gyro sensor, respectively.

[0031] The detection signals corresponding to the boom angle from the boom angle sensor S1, the detection signals corresponding to the arm angle from the arm angle sensor S2, and the detection signals corresponding to the bucket angle from the bucket angle sensor S3 are input to the controller 30. The detection signals may include angular velocity in addition to angle.

[0032] The machine tilt sensor S4 detects the tilt state of the machine (lower traveling body 1 or upper rotating body 3) relative to the horizontal plane. The machine tilt sensor S4 is, for example, attached to the upper rotating body 3 and detects the tilt angle of the shovel 100 (i.e., the upper rotating body 3) around two axes: the longitudinal direction and the lateral direction. The machine tilt sensor S4 may be, for example, an acceleration sensor, a 6-axis sensor, or an IMU. The detection signal corresponding to the tilt angle from the machine tilt sensor S4 is input to the controller 30.

[0033] The rotation sensor S5 outputs information regarding the rotation of the upper rotating body 3. The rotation sensor S5 detects, for example, the rotational angular velocity and rotational angular acceleration of the upper rotating body 3 relative to the lower traveling body 1. The rotation sensor S5 may also detect the rotation angle. The rotation sensor S5 may be, for example, a gyro sensor, a resolver, or a rotary encoder. The detection signals corresponding to the rotation angle, rotational angular velocity, and rotational angular acceleration of the upper rotating body 3 detected by the rotation sensor S5 are input to the controller 30.

[0034] The boom cylinder 7 is equipped with a boom rod pressure sensor S7R and a boom bottom pressure sensor S7B. The arm cylinder 8 is equipped with an arm rod pressure sensor S8R and an arm bottom pressure sensor S8B. The bucket cylinder 9 is equipped with a bucket rod pressure sensor S9R and a bucket bottom pressure sensor S9B. The boom rod pressure sensor S7R, boom bottom pressure sensor S7B, arm rod pressure sensor S8R, arm bottom pressure sensor S8B, bucket rod pressure sensor S9R, and bucket bottom pressure sensor S9B are collectively referred to as "cylinder pressure sensors".

[0035] The boom rod pressure sensor S7R detects the pressure in the rod-side oil chamber of the boom cylinder 7 (hereinafter referred to as "boom rod pressure"), and the boom bottom pressure sensor S7B detects the pressure in the bottom-side oil chamber of the boom cylinder 7 (hereinafter referred to as "boom bottom pressure"). The arm rod pressure sensor S8R detects the pressure in the rod-side oil chamber of the arm cylinder 8 (hereinafter referred to as "arm rod pressure"), and the arm bottom pressure sensor S8B detects the pressure in the bottom-side oil chamber of the arm cylinder 8 (hereinafter referred to as "arm bottom pressure"). The bucket rod pressure sensor S9R detects the pressure in the rod-side oil chamber of the bucket cylinder 9 (hereinafter referred to as "bucket rod pressure"), and the bucket bottom pressure sensor S9B detects the pressure in the bottom-side oil chamber of the bucket cylinder 9 (hereinafter referred to as "bucket bottom pressure").

[0036] In this embodiment, the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B are used as sensors to acquire cylinder pressure (an example of information) for deriving torque related to boom 4. However, this embodiment does not limit the sensors for acquiring information for deriving torque related to boom 4 to the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B. For example, an angular acceleration sensor (or angular velocity sensor) provided around the boom foot pin, or a strain gauge for detecting force generated on boom 4 may be used.

[0037] The positioning device PS measures the position of the upper rotating body 3. The positioning device PS is, for example, a GNSS (Global Navigation Satellite System) compass and detects the position and orientation of the upper rotating body 3. The detection signals corresponding to the position and orientation of the upper rotating body 3 are received by the controller 30. The function of detecting the orientation of the upper rotating body 3 may be realized by an orientation sensor attached to the upper rotating body 3. In this embodiment, the positioning device PS measures the current position of the shovel 100 in a globally identifiable reference coordinate system.

[0038] A reference coordinate system is, for example, the World Geodetic System, which can determine a location on Earth. The World Geodetic System is a three-dimensional orthogonal XYZ coordinate system with its origin at the Earth's center of mass, the X-axis pointing in the direction of the intersection of the Greenwich Meridian and the equator, the Y-axis pointing in the direction of 90 degrees east longitude, and the Z-axis pointing in the direction of the North Pole.

[0039] The operator's cab 10 is a compartment where the operator sits and is located on the front left side of the upper rotating body 3. However, the operator's cab 10 may be omitted if the shovel 100 is remotely controlled or if the shovel 100 operates by fully automated means.

[0040] The communication device T1 communicates with external devices through a communication network including a mobile communication network, a satellite communication network, or the Internet. The communication device T1 is, for example, a mobile communication module compatible with mobile communication standards such as LTE (Long Term Evolution), 4G (4th Generation), or 5G (5th Generation), a communication module compatible with short-range wireless communication standards such as Wi-Fi (registered trademark) or Bluetooth (registered trademark), or a satellite communication module for connecting to a satellite communication network.

[0041] The shovel 100 operates actuators in response to the operator's input from the cab 10, driving 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.

[0042] Alternatively, the shovel 100 may be configured to be remotely operated from outside the shovel 100. When the shovel 100 is remotely operated, the inside of the operator's cab 10 may be unoccupied.

[0043] Furthermore, the shovel 100 may operate its actuators automatically, regardless of the operator's actions. This enables the shovel 100 to automatically operate at least a portion of its driven parts, such as the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6, thus realizing a so-called "machine control function."

[0044] Figure 2 is a schematic diagram showing an example of the configuration of the shovel 100. In Figure 2, the mechanical power transmission system, hydraulic fluid line, pilot line, and electrical control system are indicated by double lines, thick solid lines, thick dashed lines, and dotted lines, respectively.

[0045] The drive system of the shovel 100 includes an engine 11, a regulator 13, a main pump 14, and a control valve unit 17. The hydraulic drive system of the shovel 100 also includes hydraulic actuators such as a slewing hydraulic motor 2A, a left travel hydraulic motor 2ML, a right travel hydraulic motor 2MR, a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9.

[0046] Engine 11 is an example of a power source for the shovel 100, and is mounted, for example, at the rear of the upper rotating body 3. The power source for the shovel 100 may also be a combination of a battery or fuel cell and an electric motor. Specifically, the engine 11 rotates at a constant speed at a preset target rotational speed under direct or indirect control by the controller 30, driving the main pump 14 and the pilot pump 15. Engine 11 is, for example, a diesel engine that uses light oil as fuel. Engine 11 may also be a gasoline engine or a hydrogen engine, etc.

[0047] The regulator 13 controls the discharge rate of the main pump 14. For example, the regulator 13 controls the discharge rate of the main pump 14 by adjusting the angle (tilt angle) of the swash plate of the main pump 14 in response to a control command from the controller 30.

[0048] The main pump 14, for example, is mounted at the rear of the upper rotating body 3, similar to the engine 11, and supplies 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.

[0049] The control valve unit 17 is one of the hydraulic control devices that control the hydraulic system in the excavator 100. In the illustrated example, the control valve unit 17 includes control valves 171 to 176. The control valve unit 17 is configured to selectively supply hydraulic fluid discharged by the main pump 14 to one or more hydraulic actuators through the control valves 171 to 176. The control valves 171 to 176 control the flow rate of hydraulic fluid flowing from the main pump 14 to the hydraulic actuators, and the flow rate of hydraulic fluid flowing from the hydraulic actuators to the hydraulic fluid tank. The hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left travel hydraulic motor 2ML, a right travel hydraulic motor 2MR, and a slewing hydraulic motor 2A. Specifically, control valve 171 corresponds to the left travel hydraulic motor 2ML, control valve 172 corresponds to the right travel hydraulic motor 2MR, and control valve 173 corresponds to the slewing hydraulic motor 2A. Furthermore, control valve 174 corresponds to bucket cylinder 9, control valve 175 corresponds to boom cylinder 7, and control valve 176 corresponds to arm cylinder 8.

[0050] The pilot pump 15 is an example of a pilot pressure generating device and is configured to supply hydraulic fluid to a 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 generating device may be implemented by the main pump 14. That is, the main pump 14 may have the function of supplying hydraulic fluid to the control valve unit 17 via a hydraulic fluid line, as well as the function of supplying hydraulic fluid to various hydraulic control devices via a pilot line. In this case, the pilot pump 15 may be omitted.

[0051] The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In the example shown in the figure, the discharge pressure sensor 28 outputs the detected value to the controller 30.

[0052] The operating device 26 is a device used by the operator to operate the actuator. The operating device 26 includes, for example, an operating lever and an operating pedal. The actuator may be a hydraulic actuator or an electric actuator.

[0053] The operation sensor 29 is configured to detect the operator's actions using the operation device 26. In this embodiment, the operation sensor 29 detects the operating direction and amount of the operation device 26 corresponding to each actuator and outputs the detected values ​​to the controller 30. In the illustrated example, the controller 30 can control the opening area of ​​the proportional valve 31 according to the output of the operation sensor 29. The controller 30 then supplies 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 pressure of the hydraulic fluid supplied to each pilot port (pilot pressure) is, in principle, the pressure corresponding to the operating direction and amount of the operation device 26 corresponding to each hydraulic actuator. Thus, the operation device 26 is configured 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.

[0054] The proportional valve 31, which functions as a control valve for machine control, is located in the pipeline connecting the pilot pump 15 and the pilot port of the control valve in the control valve unit 17, and is configured to change the flow area of ​​the pipeline. In the illustrated example, the proportional valve 31 operates in response to control commands output by the controller 30. Therefore, the controller 30 can adjust the pilot pressure acting on the pilot port of the control valve by the proportional valve 31, independently of the operation of the operating device 26 by the operator.

[0055] This configuration allows the controller 30 to operate the hydraulic actuator corresponding to a specific operating device 26 even when no operation is being performed on that particular operating device 26.

[0056] Furthermore, as shown in Figure 2, the control system of the shovel 100 includes a controller 30, a storage device ST, a display device D1, an input device D2, and a communication device T1, etc.

[0057] The display device D1 is located in a place easily visible to a seated operator in the driver's cab 10 and displays various information images under the control of the controller 30. In the illustrated example, the display device D1 is located to the right front of the driver's seat and is connected to the controller 30 via a dedicated line. The display device D1 displays various image information. The display device D1 includes a display screen that displays information such as the working conditions or operating status of the shovel 100. The operator seated in the driver's seat can perform work with the shovel 100 while checking the various information displayed on the display device D1. The display device D1 may also be provided with an input device D2.

[0058] The input device D2 is located within reach of the operator seated in the driver's seat and receives various operation inputs from the operator, outputting signals corresponding to the operation inputs to the controller 30. The input device D2 includes a touch panel mounted on the display of the display device D1 which displays various information images, a knob switch provided at the tip of one or more of the operation levers included in the operation device 26, or a button switch, lever, toggle switch, or rotary dial installed around the display device D1. Signals corresponding to the content of operations on the input device D2 are received by the controller 30.

[0059] The controller 30 is configured to output control commands to the regulator 13 as needed, thereby changing the discharge rate of the main pump 14.

[0060] Furthermore, the controller 30 may be configured to perform control related to a machine guidance function that guides the manual operation of the shovel 100 by the operator through the operating device 26. Alternatively, the controller 30 may be configured to perform control related to a machine control function that automatically assists the manual operation of the shovel 100 by the operator through the operating device 26.

[0061] Furthermore, some of the functions of controller 30 may be implemented by other controllers (control devices). In other words, the functions of controller 30 may be implemented in a manner distributed among multiple controllers. For example, machine guidance functions and machine control functions may be implemented by dedicated controllers (control devices).

[0062] The storage device ST is, for example, located in the operator's cab 10 and stores various information under the control of the controller 30. The storage device ST is, for example, a non-volatile storage medium such as a semiconductor memory. The storage device ST may store information output by various devices during the operation of the shovel 100, or it may store information acquired via various devices before the operation of the shovel 100 begins. The storage device ST may store data relating to the target construction surface, acquired via a communication device T1, or set via an input device D2, for example. The target construction surface may be set (saved) by the operator of the shovel 100, or by a construction manager, etc.

[0063] Furthermore, the memory device ST is equipped with a pre-trained model LM.

[0064] [Forces acting on the shovel] Next, with reference to Figure 3, the method for calculating the excavation reaction force using the controller 30 according to this embodiment will be described. Figure 3 is a conceptual diagram illustrating the method for calculating the excavation reaction force using the controller 30 according to this embodiment.

[0065] The boom angle sensor S1 shown in Figure 3 acquires, for example, the boom angle θ1. The boom angle θ1 is the angle of the line segment P1-P2, which connects the boom foot pin position P1 and the arm connecting pin position P2, with respect to the horizontal line in the XZ plane.

[0066] The arm angle sensor S2 acquires, for example, the arm angle θ2. The arm angle θ2 is the angle of the line segment P2-P3, which connects the arm connecting pin position P2 and the bucket connecting pin position P3, with respect to the horizontal line in the XZ plane.

[0067] The bucket angle sensor S3 acquires, for example, the bucket angle θ3. The bucket angle θ3 is the angle of the line segment P3-P4, which connects the bucket connecting pin position P3 and the bucket toe position P4, with respect to the horizontal line in the XZ plane.

[0068] The cylinder pressure sensors S7R, S7B, S8R, S8B, S9R, and S9B detect, for example, boom bottom pressure (P11), boom rod pressure (P12), arm bottom pressure (P13), arm rod pressure (P14), bucket bottom pressure (P15), and bucket rod pressure (P16).

[0069] Cylinder thrust is calculated, for example, based on the cylinder pressure and the pressure-receiving area of ​​the piston sliding inside the cylinder. For example, as shown in Figure 3, the boom cylinder thrust (f1) is expressed as the difference between the cylinder extension force, which is the product of the boom bottom pressure (P11) and the pressure-receiving area of ​​the piston in the boom bottom side oil chamber (A11) (P11 × A11), and the cylinder contraction force, which is the product of the boom rod pressure (P12) and the pressure-receiving area of ​​the piston in the boom rod side oil chamber (A12) (P12 × A12) (P11 × A12).

[0070] Similarly, the arm cylinder thrust (f2) is expressed as the difference between the cylinder extension force and the cylinder contraction force (P13 × A13 - P14 × A14), and the bucket cylinder thrust (f3) is also expressed as the difference between the cylinder extension force and the cylinder contraction force (P15 × A15 - P16 × A16). Note that A13 is the pressure-receiving area of ​​the piston in the arm bottom side oil chamber, A14 is the pressure-receiving area of ​​the piston in the arm rod side oil chamber, A15 is the pressure-receiving area of ​​the piston in the bucket bottom side oil chamber, and A16 is the pressure-receiving area of ​​the piston in the bucket rod side oil chamber.

[0071] The drilling torque is calculated, for example, based on the attitude of the drilling attachment and the cylinder thrust. For example, as shown in Figure 11, the magnitude of the bucket drilling torque (τ3) is expressed by multiplying the magnitude of the bucket cylinder thrust (f3) by the distance G3 between the line of action of the bucket cylinder thrust (f3) and the bucket linking pin position P3. The distance G3 is a function of the bucket angle (θ3) and is considered an example of link gain.

[0072] Similarly, the boom digging torque (τ1) is expressed by multiplying the magnitude of the boom cylinder thrust (f1) by the distance G1 between the line of action of the boom cylinder thrust (f1) and the boom foot pin position P1. Similarly, the arm digging torque (τ2) is expressed by multiplying the magnitude of the arm cylinder thrust (f2) by the distance G2 between the line of action of the arm cylinder thrust (f2) and the arm connecting pin position P2.

[0073] The digging reaction force F is calculated, for example, based on the posture of the digging attachment and the digging load. For example, the digging reaction force F is calculated based on a function (mechanism function) that takes physical quantities representing the posture of the digging attachment as arguments, and a function that takes physical quantities representing the digging load as arguments. Specifically, as shown in Figure 11, the digging reaction force F is calculated as the product of a mechanism function that takes boom angle (θ1), arm angle (θ2), and bucket angle (θ3) as arguments, and a function that takes boom digging torque (τ1), arm digging torque (τ2), and bucket digging torque (τ3) as arguments. These functions shall be determined according to the structure of the shovel 100, etc.

[0074] Functions that take physical quantities representing the drilling load as arguments are not limited to functions that take boom drilling torque (τ1), arm drilling torque (τ2), and bucket drilling torque (τ3) as arguments, but may also take boom cylinder thrust (f1), arm cylinder thrust (f2), and bucket cylinder thrust (f3) as arguments. Furthermore, instead of cylinder thrust, the detected values ​​of cylinder pressure sensors S7R, S7B, S8R, S8B, S9R, and S9B may be used directly as physical quantities representing the drilling load used as arguments to the function.

[0075] The mechanism function, with boom angle (θ1), arm angle (θ2), and bucket angle (θ3) as arguments, may be based on force equilibrium equations, on the Jacobian, or on the principle of virtual work.

[0076] The excavation reaction force F can be calculated through the process described above. The excavation reaction force F will increase as the soil being excavated becomes harder. When the excavation reaction force F exceeds the reaction force determined by the limits of the mechanism of the shovel 100 (hereinafter referred to as the limit reaction force Ft), it becomes difficult for the attachment AT to advance further, and excavation may stop. Therefore, the controller 30 according to this embodiment operates the attachment AT so that the excavation reaction force F does not exceed the limit reaction force Ft.

[0077] [Details of machine control functions] Next, with reference to Figure 4, the functions of the controller 30 of the shovel 100 will be described in detail.

[0078] Figure 4 is a functional block diagram showing an example of the functional configuration of the controller 30 of the shovel 100 according to this embodiment.

[0079] The memory device ST stores the learned model LM and the limit reaction force memory unit ST1.

[0080] The trained model LM is primarily constructed using a neural network. The neural network of the trained model LM may be a so-called deep neural network, which has one or more hidden layers between the input and output layers. In the neural network, each of the multiple neurons constituting each hidden layer has a weighting parameter defined that represents the strength of the connection with the lower layer. The neural network is constructed in such a way that the neurons in each layer output to the neurons in the lower layer the sum of the values ​​obtained by multiplying each input value from the multiple neurons in the upper layer by the weighting parameter defined for each neuron in the upper layer, through a threshold function.

[0081] When machine learning, specifically deep learning, is applied to a pre-trained neural network (LM), the weighting parameters of the neural network are optimized.

[0082] The training data used in machine learning includes, for example, the shape of the soil to be excavated, represented in three dimensions; the target trajectory for excavating through that soil shape; the shape of the bucket 6; and the reaction force (hereinafter referred to as predicted excavation reaction force) that is estimated to occur on the bucket 6 at each position along the target trajectory when the bucket 6 is excavated along the target trajectory. The trained model LM is standardized using this training data.

[0083] Then, when the trained model LM receives input such as the soil shape represented by the three-dimensional shape of the target to be excavated, detected by the spatial recognition device S10, the target trajectory acquired by the target trajectory acquisition unit 302 (described later), and the shape of the bucket 6, it outputs a predicted excavation reaction force that is estimated to be generated for the bucket 6 at each position on the target trajectory when the bucket 6 is operated along the target trajectory.

[0084] This embodiment is not limited to a method of mounting the trained model LM on the shovel 100, but may also be implemented on a cloud service. In other words, the shovel 100 transmits to the cloud service the soil shape represented by the three-dimensional shape of the target to be excavated, detected by the spatial recognition device S10, the target trajectory acquired by the target trajectory acquisition unit 302 (described later), and the shape of the bucket 6. From the cloud service, it is possible to receive predicted excavation reaction forces that are estimated to be generated on the bucket 6 at each position on the target trajectory when the bucket 6 is operated along the target trajectory.

[0085] The limit reaction force memory unit ST1 stores the limit reaction force Ft at which the attachment AT of the shovel 100 may stop moving when it is excavating. The limit reaction force Ft is determined according to the characteristics of the shovel 100.

[0086] The controller 30 has a machine control function, which is realized, for example, by executing one or more programs stored in ROM or a non-volatile auxiliary storage device on the CPU.

[0087] The controller 30 controls the shovel 100 according to, for example, the machine control function. The controller 30 repeatedly performs automatic excavation operations using at least one of the boom 4, arm 5, and bucket 6 until the shape of the soil of the shovel 100 matches the target construction surface. Data regarding the target construction surface is pre-stored in, for example, the memory device ST described above. The data regarding the target construction surface is expressed in, for example, a reference coordinate system. The reference coordinate system is, for example, the World Geodetic System. The World Geodetic System is a three-dimensional orthogonal XYZ coordinate system with its origin at the center of gravity of the Earth, the X-axis pointing in the direction of the intersection of the Greenwich Meridian and the equator, the Y-axis pointing in the direction of 90 degrees east longitude, and the Z-axis pointing in the direction of the North Pole. Alternatively, the operator may designate any point on the construction site as a reference point and set the target construction surface by its relative positional relationship with the reference point via the input device D2.

[0088] By the way, when using the attachment AT for excavation, it is difficult to set criteria for determining whether or not excavation by the attachment AT will stop. For example, if the criterion is whether or not the current excavation reaction force F acting on the attachment AT is equal to or greater than the critical reaction force Ft, then excavation by the attachment AT will stop when the critical reaction force Ft is exceeded. For this reason, it is difficult to use whether or not the current excavation reaction force F acting on the attachment AT is equal to or greater than the critical reaction force Ft as the criterion. Also, if the criterion is a predetermined reaction force obtained by reducing a predetermined margin from the critical reaction force Ft, even if the current excavation reaction force F acting on the attachment AT reaches the predetermined reaction force, depending on the point at which the predetermined reaction force is reached, it may be possible to continue excavating and complete the excavation without reaching the critical reaction force Ft.

[0089] In other words, it is preferable to determine whether the predicted excavation reaction force that is estimated to occur at attachment AT if excavation continues as is will be greater than or equal to the critical reaction force Ft, rather than the current excavation reaction force F.

[0090] Therefore, the controller 30 according to this embodiment calculates the predicted excavation reaction force that is estimated to occur in the attachment AT while excavating according to the target trajectory, based on the soil shape around the shovel 100 and the target trajectory that a predetermined part of the attachment AT is to follow, which are included in the detection results acquired by the spatial recognition device S10, and controls the attachment AT to move in a direction that reduces the excavation reaction force F based on the predicted excavation reaction force.

[0091] In this embodiment, the controller 30 operates the attachment AT in a direction that reduces the excavation reaction force F based on the predicted excavation reaction force, thereby preventing the reaction force generated in the attachment AT from becoming greater than the limit reaction force Ft and stopping the attachment AT.

[0092] In this embodiment, the case in which the controller 30 autonomously operates the boom 4, arm 5, and bucket 6 is described. However, this is not limited to autonomous operation. When an operator is manually operating the equipment, semi-automatic control may be performed to operate at least one of the boom 4, arm 5, and bucket 6 so that the soil shape conforms to the target construction surface.

[0093] The acquisition unit 301 acquires information from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine tilt sensor S4, rotation sensor S5, imaging device S6, cylinder pressure sensors S7R, S7B, S8R, S8B, S9R, S9B, spatial recognition device S10, positioning device PS, communication device T1, and input device D2, etc.

[0094] The target trajectory acquisition unit 302 comprises a selection unit 1301, an estimation unit 1302, and a determination unit 1303, and acquires a target trajectory, which is the trajectory followed by a predetermined part of the attachment AT (for example, the tip of the bucket 6) when the shovel 100 is operated autonomously. In this embodiment, the target trajectory acquisition unit 302 stores in advance multiple trajectories followed by a predetermined part of the attachment AT in a storage device ST or the like. Each of the multiple target paths differs in the depth at which excavation is performed, the amount of soil that the bucket 6 can excavate, etc.

[0095] The selection unit 1301 selects one target trajectory from a plurality of target trajectories based on the shape of the soil around the shovel 100 and the shape of the bucket 6, which are included in the detection results (an example of information) acquired by the spatial recognition device S10. In this embodiment, for example, the selection unit 1301 selects a target path that allows excavation of soil corresponding to the capacity of the bucket 6 provided on the attachment AT, based on the detected soil shape. A well-known method may be used for selecting the specific target path. Furthermore, the method is not limited to selecting the target path, and a target path may be generated according to the soil shape.

[0096] Then, the estimation unit 1302 calculates the predicted excavation reaction force that is estimated to occur in the attachment AT while excavating according to the target trajectory, based on the soil shape around the shovel 100, the target trajectory determined for excavating with respect to the soil shape, and the shape of the bucket 6, which are included in the detection results (an example of information) acquired by the spatial recognition device S10.

[0097] Specifically, the estimation unit 1302 inputs the soil shape around the shovel 100, the target trajectory, and the shape of the bucket 6 into the learned model LM, and receives from the learned model LM the predicted excavation reaction force that is estimated to be generated at each position on the target trajectory relative to a predetermined part of the attachment AT when the attachment AT is operated so that a predetermined part follows the target trajectory.

[0098] Figure 5 shows an example of a target trajectory acquired by the target trajectory acquisition unit 302 according to this embodiment. In the example shown in Figure 5, the selection unit 1301 selects a target trajectory 1510 corresponding to the capacity of the bucket 6 based on the soil shape 1501 acquired by the spatial recognition device S10 (S10F).

[0099] The estimation unit 1302 then inputs the soil shape 1501 surrounding the shovel 100, the target trajectory 1510, and the shape of the bucket 6 into the learned model LM, and receives the predicted excavation reaction force that is estimated to be occurring at each of the points 1511 to 1520 on the target trajectory 1510 relative to a predetermined part of the attachment AT.

[0100] The determination unit 1303 determines whether the predicted excavation reaction force calculated for each position on the target trajectory is greater than or equal to the limit reaction force Ft stored in the limit reaction force storage unit ST1. If the determination unit 1303 determines that all of the predicted excavation reaction forces calculated for each position on the target trajectory are less than the limit reaction force Ft, it outputs the target trajectory to the operation control unit 303 in order to perform autonomous operation using that target trajectory.

[0101] If the determination unit 1303 determines that at least one of the predicted excavation reaction forces calculated for each position on the target trajectory is greater than or equal to the critical reaction force Ft, the selection unit 1301 selects a target trajectory in which the attachment AT is operated in a direction that reduces the excavation reaction force F, compared to the currently selected target trajectory. Subsequently, the estimation unit 1302 calculates the predicted excavation reaction force for each position on the target trajectory, and the determination unit 1303 determines whether the predicted excavation reaction force for each position on the target trajectory is greater than or equal to the critical reaction force Ft. By repeating this process, the target trajectory in which all of the predicted excavation reaction forces calculated for each position on the target trajectory are less than the critical reaction force Ft is output to the operation control unit 303.

[0102] As described above, the target trajectory acquisition unit 302 according to this embodiment modifies the target trajectory so that the attachment AT moves in a direction that reduces the excavation reaction force F when it is determined that the predicted excavation reaction force calculated for each position on the target trajectory is equal to or greater than the limit reaction force Ft. In this embodiment, by using a target trajectory that has been modified to move the attachment AT in a direction that reduces the excavation reaction force F, it is possible to suppress the stopping of excavation due to the excavation reaction force F while moving the attachment AT along the target trajectory, thereby improving work efficiency.

[0103] In this embodiment, an example of correcting the target trajectory in order to operate the attachment AT in a direction that reduces the excavation reaction force F has been described. However, this embodiment is not limited to control that corrects the target trajectory in order to operate the attachment AT in a direction that reduces the excavation reaction force F. In other words, the controller 30 only needs to control the attachment AT in a direction that reduces the excavation reaction force F when the calculated predicted excavation reaction force is greater than the limit reaction force Ft (an example of a first reaction force) which is defined as the criterion for stopping the operation of the attachment AT. In other words, in this embodiment, if it is estimated that the predicted excavation reaction force that is expected to occur in the attachment AT during excavation will be greater than the limit reaction force Ft, the attachment AT can be operated in advance before reaching the limit reaction force Ft, thereby preventing the attachment AT from stopping during excavation.

[0104] In this embodiment, the direction in which the excavation reaction force F decreases can be determined according to the embodiment. For example, at least one of the following may be used as the control direction: the closing direction of the bucket 6, the raising direction of the boom 4, and the closing or opening direction of the arm 5. Alternatively, at least one or more may be used in combination as the control direction.

[0105] The motion control unit 303 includes a lifting amount adjustment unit 1311, a signal output unit 1312, an excavation reaction force calculation unit 1313, a reaction force estimation unit 1314, and a calculation unit 1315. The motion control unit 303 acquires a target trajectory from the target trajectory acquisition unit 302, calculated so that the predicted excavation reaction force does not exceed the critical reaction force Ft, and controls the operation of the attachment AT according to the acquired target trajectory. When the attachment AT is operated along a target trajectory calculated so that the predicted excavation reaction force does not exceed the critical reaction force Ft, it is possible to suppress the attachment AT from reaching the critical reaction force Ft, thereby improving work efficiency.

[0106] The lifting amount adjustment unit 1311 adjusts the lifting amount of the boom 4 to follow the target trajectory based on the target trajectory input from the target trajectory acquisition unit 302. The lifting amount adjustment unit 1311 also adjusts the lifting amount of the boom 4 using the calculation results from the calculation unit 1315, but this adjustment will be described later.

[0107] The signal output unit 1312 generates a control signal to operate the boom 4 so that it reaches the lifting amount adjusted by the lifting amount adjustment unit 1311, and outputs the generated control signal to the proportional valve 31.

[0108] The excavation reaction force calculation unit 1313 calculates the actual excavation reaction force F occurring at a predetermined part of the attachment AT (for example, the tip of the bucket 6) based on the boom angle, arm angle, bucket angle, and cylinder pressure acquired by the acquisition unit 301. The method for calculating the excavation reaction force F is as described above and will not be explained further.

[0109] The reaction force estimation unit 1314 estimates the reaction force generated on the attachment AT until the attachment AT completes its excavation operation along the target trajectory, based on the difference between the predicted excavation reaction force calculated for each position on the target trajectory and the excavation reaction force F calculated by the excavation reaction force calculation unit 1313.

[0110] Figure 6 is a graph showing the excavation reaction force F generated in the attachment AT during excavation by the shovel 100 according to this embodiment. In the graph shown in Figure 6, the vertical axis represents the reaction force [N] and the horizontal axis represents time. The graph shows the reaction force that changes over time when excavation is performed. Line 1701 shows the predicted excavation reaction force estimated when the attachment AT is operated along the target trajectory.

[0111] Line 1702A shows the change in the actual excavation reaction force F calculated by the excavation reaction force calculation unit 1313.

[0112] In the example shown in Figure 6, the actual excavation reaction force F, indicated by line 1702A, is greater than the estimated predicted excavation reaction force, indicated by line 1701.

[0113] Therefore, if excavation continues and the excavation reaction force F continues to increase, it may become larger than the critical reaction force Ft. Accordingly, the reaction force estimation unit 1314 in this embodiment estimates the reaction force generated in the attachment AT until the attachment AT finishes moving along the target trajectory, based on the excavation reaction force F calculated by the excavation reaction force calculation unit 1313, shown by line 1702A, and the previously estimated predicted excavation reaction force, shown by line 1701.

[0114] Line 1702B represents the reaction force estimated by the reaction force estimation unit 1314, which is estimated to occur on the attachment AT until the attachment AT completes its movement along the target trajectory. The change in reaction force shown by line 1702B indicates that at time t3, the reaction force exceeds or exceeds the critical reaction force Ft.

[0115] The method for calculating the reaction force estimated to occur on the attachment AT as it moves along the target trajectory until the attachment AT completes its operation, as shown by line 1702B, can be any method. In this embodiment, the reaction force estimation unit 1314 calculates, for example, the ratio value (F12 / F11) of the calculated excavation reaction force F11 to the predicted excavation reaction force F12 on the target trajectory at time t1, and calculates the reaction force estimated to occur on the attachment AT until the attachment AT completes its operation by multiplying the predicted excavation reaction force at each position on the target trajectory by the ratio value (F12 / F11). This allows for the derivation of the reaction force estimated to occur on the attachment AT as it moves along the target trajectory until the attachment AT completes its operation, as shown by line 1702B.

[0116] For example, the reaction force estimation unit 1314 calculates the largest reaction force among the reaction forces estimated to occur on the attachment AT until the operation of the attachment AT is completed. In the example shown in Figure 6, the reaction force estimation unit 1314 calculates the largest reaction force F14 = F13 × (F12 / F11).

[0117] The reaction force estimation unit 1314 then determines whether the calculated reaction force F14 is greater than or equal to the critical reaction force Ft (an example of the first reaction force). If it determines that the reaction force F14 is greater than or equal to the critical reaction force Ft (an example of the first reaction force), the reaction force estimation unit 1314 outputs the reaction force F14 to the calculation unit 1315.

[0118] On the other hand, if the reaction force estimation unit 1314 predicts that the reaction force estimated to occur in the attachment AT will not exceed the limit reaction force Ft (an example of a first reaction force) which is defined as the criterion for stopping the operation of the attachment AT, the reaction force estimation unit 1314 outputs the limit reaction force Ft. Note that this embodiment is not limited to outputting the limit reaction force Ft, and may output the calculated reaction force.

[0119] The calculation unit 1315 outputs to the lift adjustment unit 1311 a value obtained by subtracting the limit reaction force Ft input from the limit reaction force storage unit ST1 from the reaction force input from the reaction force estimation unit 1314. If the limit reaction force Ft is input from the reaction force estimation unit 1314, control along the target trajectory will continue. If a value smaller than the limit reaction force Ft is input, a negative value will be output to the lift adjustment unit 1311.

[0120] The lifting amount adjustment unit 1311 adjusts the lifting amount of the boom 4 based on the target trajectory input from the target trajectory acquisition unit 302 and the value input from the calculation unit 1315. The lifting amount adjustment method can be any method; for example, if a positive value is input from the calculation unit 1315, the lifting amount may be calculated by multiplying the input value by a predetermined gain, or if a positive value is input from the calculation unit 1315, a predetermined value may be used as the lifting amount.

[0121] Furthermore, if a negative value is input from the calculation unit 1315, and the absolute value of the negative value is greater than a predetermined threshold, a predetermined value may be used as the lowering amount, and control may be performed to lower the boom 4.

[0122] The lift amount adjustment unit 1311 then adjusts the target trajectory to raise (or lower) according to the lift amount (or lower amount).

[0123] Thus, when the lifting amount adjustment unit 1311 predicts that the reaction force estimated to occur in the attachment AT will be greater than the limit reaction force Ft (an example of the first reaction force) which is defined as the criterion for stopping the operation of the attachment AT, it corrects the target trajectory upward and operates the attachment AT in a direction that reduces the excavation reaction force F.

[0124] The signal output unit 1312 outputs a control signal to align with the corrected target trajectory. This causes the attachment AT to be raised. Subsequently, the excavation reaction force calculation unit 1313 calculates the actual excavation reaction force F acting on the bucket 6, and the reaction force estimation unit 1314 calculates the largest reaction force among those estimated to act on the attachment AT until the attachment AT's operation is completed. If the calculated reaction force is greater than the critical reaction force Ft, the reaction force estimation unit 1314 outputs the calculated reaction force to the calculation unit 1315. The lifting amount adjustment unit 1311 then corrects the target trajectory according to the input from the calculation unit 1315.

[0125] In this embodiment, the above-described control is repeated until the reaction force calculated by the reaction force estimation unit 1314 becomes less than or equal to the critical reaction force Ft.

[0126] Subsequently, when the calculated reaction force falls below the limit reaction force Ft, the reaction force estimation unit 1314 outputs the limit reaction force Ft, and the calculation unit 1315 outputs "0" to the lifting amount adjustment unit 1311. In this case, the lifting amount adjustment unit 1311 adjusts the lifting amount of the boom 4 to align with the already corrected target trajectory.

[0127] Line 1703 shows the estimated reaction force that will occur on attachment AT until the excavation operation is completed, after the reaction force generated on attachment AT has decreased as a result of the adjustment of the height of boom 4 at time t2.

[0128] Thus, if the motion control unit 303 predicts that the reaction force estimated to occur in the attachment AT will exceed the limit reaction force Ft (an example of the first reaction force) which is defined as the criterion for stopping the operation of the attachment AT, it operates the attachment AT in a direction that reduces the excavation reaction force F. In this embodiment, by operating the attachment AT in a direction that reduces the excavation reaction force F, it is possible to prevent the excavation reaction force F from reaching the limit reaction force Ft, thereby enabling the continuation of excavation and improving work efficiency.

[0129] Furthermore, even after moving the attachment in a direction that reduces the excavation reaction force F, the motion control unit 303 controls the attachment AT to follow the corrected target trajectory, so that the reaction force generated in the attachment AT does not exceed the limit reaction force Ft, and the excavation operation can be performed until time t4.

[0130] In this embodiment, by performing the control described above, it is possible to suppress the reaction force generated in the attachment AT during excavation from exceeding the critical reaction force Ft. In other words, it is possible to suppress the interruption of excavation due to an increase in the excavation reaction force, thereby suppressing a decrease in work efficiency.

[0131] In this way, the motion control unit 303 modifies the target trajectory to include movement of the attachment AT in the direction that reduces the excavation reaction force F, and operates the attachment AT along the modified target trajectory. Therefore, by operating the attachment AT in the direction that reduces the excavation force and operating the attachment AT along the target trajectory, it is possible to suppress the reaction force generated in the attachment AT from reaching the critical reaction force Ft, and to continue the operation of the attachment AT along the target trajectory, thereby suppressing interruptions to the excavation operation and improving work efficiency. Next, the modified target trajectory will be described. The attachment AT is operated along the modified target trajectory.

[0132] Furthermore, in this embodiment, the control is not limited to moving the attachment AT in a direction that decreases the excavation reaction force F. For example, based on the excavation reaction force F calculated by the excavation reaction force calculation unit 1313 and the predicted excavation reaction force, the operation control unit 303 may consider the actual excavation reaction force F to be smaller than expected if the maximum reaction force generated at the attachment AT during excavation is smaller than the limit reaction force Ft, and the difference between the maximum reaction force and the limit reaction force Ft is greater than a predetermined threshold, and may move the attachment AT in a direction that increases the excavation reaction force F. By performing this control, the operation control unit 303 can increase the amount of excavation and improve work efficiency.

[0133] Figure 7 illustrates the trajectory of the bucket 6 provided on the shovel 100 according to this embodiment. Line 1801 represents the shape of the soil detected by the spatial recognition device S10. The target trajectory acquisition unit 302 acquires the target trajectory shown by lines 1802A and 1802B, taking the shape of the soil into consideration. Then, the bucket 6 (6A) moves along line 1802A, which is shown on the target trajectory, and excavation begins.

[0134] Furthermore, the predetermined portion of the bucket 6 provided on the attachment AT is assumed to have reached position 1811 along line 1802A.

[0135] Then, when the bucket 6 reaches position 1811, the motion control unit 303 estimates that when it moves along the target trajectory line 1802B and reaches position 1812, the reaction force on a predetermined part of the bucket 6 will reach the critical reaction force Ft.

[0136] Therefore, when the boom 4 reaches position 1811, the motion control unit 303 performs an upward movement of the boom 4. It moves the bucket 6 (6B) upward until a predetermined part of it reaches position 1813. Then, from position 1813, the motion control unit 303 uses line 1803, which is parallel to line 1802B, as the target trajectory.

[0137] The motion control unit 303 then controls the bucket 6 (6B) so that a predetermined portion moves along the target trajectory, which is line 1803.

[0138] Thus, the motion control unit 303 operates the attachment AT in a direction that reduces the excavation reaction force F, based on the predicted excavation reaction force estimated to occur in the attachment AT while excavating along the target trajectory, and the excavation reaction force F calculated based on the information acquired by the cylinder pressure sensor while operating the attachment AT along the target trajectory, based on the detection results (an example of information) acquired by the spatial recognition device S10, which include the shape of the soil around the shovel 100 and the target trajectory input from the target trajectory acquisition unit 302.

[0139] Figure 7 shows an example where the boom 4 is moved upward as a direction in which the excavation reaction force F decreases. However, in this embodiment, the direction in which the excavation reaction force F decreases is not limited to the upward direction of the boom 4, but may also be the closing direction of the bucket 6, or the closing or opening direction of the arm 5, or a combination of these directions.

[0140] The processing procedure performed by the controller 30 according to this embodiment will now be described. Figure 8 is a flowchart showing the processing procedure for autonomous drilling operation by the attachment AT in the controller 30 according to this embodiment.

[0141] First, the acquisition unit 301 acquires the shape of the soil around the shovel 100 from the detection results of the spatial recognition device S10 (S1601).

[0142] Next, the selection unit 1301 selects one of several target trajectories (S1602) based on the shape of the soil around the shovel 100 and the shape of the bucket 6, which are included in the detection results (an example of information) acquired by the spatial recognition device S10.

[0143] The estimation unit 1302 inputs the soil shape around the shovel 100, the target trajectory, and the shape of the bucket 6 into the learned model LM, and receives from the learned model LM the predicted excavation reaction force that is estimated to occur at each predetermined location on the target trajectory when the attachment AT is operated so that a predetermined part of the bucket 6 follows the target trajectory (S1603).

[0144] The determination unit 1303 determines whether the predicted excavation reaction force at each position on the target trajectory is less than the limit reaction force Ft stored in the limit reaction force storage unit ST1 (S1604). If it is determined to be greater than or equal to the limit reaction force Ft (S1604: NO), the selection unit 1301 selects a target trajectory that moves the attachment AT in a direction that reduces the excavation reaction force F compared to the currently selected target trajectory (S1605). Then, the process returns to S1603.

[0145] On the other hand, if the determination unit 1303 determines that the predicted excavation reaction force for each position on the target trajectory is smaller than the limit reaction force Ft stored in the limit reaction force storage unit ST1 (S1604: YES), the operation control unit 303 starts excavation so that a predetermined part of the attachment AT moves along the target trajectory (S1606). At that time, the lifting amount adjustment unit 1311 adjusts the lifting amount of the attachment AT to follow the target trajectory, and the signal output unit 1312 outputs a control signal based on the adjustment result.

[0146] After excavation has started, the excavation reaction force calculation unit 1313 calculates the actual excavation reaction force F occurring at a predetermined part of the attachment AT based on the boom angle, arm angle, bucket angle, and cylinder pressure acquired by the acquisition unit 301 (S1607).

[0147] The reaction force estimation unit 1314 estimates the reaction force generated at a predetermined part of the attachment AT by the time the excavation operation, which moves the predetermined part of the attachment AT along the target trajectory, is completed, based on the difference between the predicted excavation reaction force calculated for each position on the target trajectory and the excavation reaction force F calculated by the excavation reaction force calculation unit 1313 (S1608).

[0148] The reaction force estimation unit 1314 determines whether the estimated reaction force is less than the limit reaction force Ft stored in the limit reaction force storage unit ST1 (S1609). If it determines that the estimated reaction force is greater than or equal to the limit reaction force Ft stored in the limit reaction force storage unit ST1 (S1609: NO), it outputs the estimated reaction force to the calculation unit 1315. The lifting amount adjustment unit 1311 then corrects the target trajectory so that the attachment moves in a direction that decreases the excavation reaction force F according to the value input to the calculation unit 1315 (the value obtained by subtracting the limit reaction force Ft from the estimated reaction force) (S1610). The signal output unit 1312 then outputs a control signal to move the attachment AT in a direction that decreases the excavation reaction force F in accordance with the target trajectory, and continues the excavation operation (S1611). After that, processing resumes from S1607.

[0149] On the other hand, if the estimated reaction force is determined to be smaller than the limit reaction force Ft stored in the limit reaction force memory unit ST1 (S1609: YES), the motion control unit 303 continues the excavation operation to move a predetermined part of the bucket 6 according to the target trajectory (S1612).

[0150] Subsequently, the motion control unit 303 determines whether or not the excavation operation according to the target trajectory has been completed (S1613). If it determines that the excavation operation has not been completed (S1613: NO), the process returns to S1607.

[0151] On the other hand, the motion control unit 303 terminates processing when it determines that the excavation operation according to the target trajectory has been completed (S1613: YES).

[0152] (Second embodiment) In a second embodiment, a case is described in which a remote system for operating the shovel 100 is provided.

[0153] Next, with reference to Figure 9, an example configuration of the remote control system (an example of a control system) SYS according to the second embodiment will be described. Figure 9 is a schematic diagram showing an example configuration of the remote control system SYS according to the second embodiment. As shown in Figure 9, the remote control system SYS includes a shovel 100, a remote control room RC, and a management center MC. Note that the detailed configuration of the shovel 100 is omitted in Figure 9 because the shovel 100 shown in Figure 9 has the same configuration as the shovel 100 shown in Figure 1.

[0154] The excavator 100, the remote control room RC, and the management center MC are connected to each other so that data can be sent and received via a communication network NW. Alternatively, the excavator 100, the remote control room RC, and the management center MC may be connected to each other directly so that data can be sent and received without using the communication network NW. In the illustrated example, the excavator 100 transmits information about the work site to the remote control room RC. This allows the remote operator RO in the remote control room RC to understand the situation at the work site based on the information from the excavator 100.

[0155] For example, the shovel 100 transmits image information captured by the imaging device S6 and sound signals representing sound collected by the external sound collection device M1 to the remote control room RC.

[0156] The shovel 100 is equipped with sensors capable of recognizing the position and shape of objects present at the work site in three dimensions. For example, the shovel 100 is equipped with a spatial recognition device S10. Therefore, the shovel 100 can transmit the results of three-dimensional measurements of the work site to the remote control room RC.

[0157] The SYS remote control system may include one or more excavators 100. If it includes multiple excavators 100, the RO (Remote Operator) of a particular excavator 100 can obtain information about the work sites obtained by that particular excavator 100, as well as information about the work sites obtained by the other one or more excavators 100.

[0158] The remote control room RC is equipped with a communication device T2, a remote controller R40, an operating device R42, an operating sensor R43, and a display device D1E. The remote control room RC also contains an operating seat DS where the remote operator RO sits to remotely control the shovel 100.

[0159] The communication device T2 is configured to communicate with the communication device T1 attached to the shovel 100.

[0160] The remote controller R40 is a computing device that performs various calculations. In this embodiment, the remote controller R40 is composed of a microcomputer including a CPU and memory. The various functions of the remote controller R40 are realized by the CPU executing a program stored in memory.

[0161] The display device D1E is a device capable of displaying various types of information. The display device D1E displays images based on information transmitted from the shovel 100 so that the remote operator RO in the remote control room RC can visually inspect the area around the shovel 100. In the illustrated example, the display device D1E is a liquid crystal display that displays images captured by the imaging device S6 mounted on the shovel 100. The display device D1E may also be a display or projector that enables naked-eye stereoscopic viewing, or it may be a VR goggle or the like.

[0162] The operating device R42 is equipped with an operating sensor R43 for detecting the operation of the operating device R42. The operating sensor R43 is, for example, a tilt sensor that detects the tilt angle of the operating lever, or an angle sensor that detects the swing angle of the operating lever around its pivot axis. The operating sensor R43 may also consist of other sensors such as a pressure sensor, a current sensor, a voltage sensor, or a distance sensor. The operating sensor R43 outputs information regarding the operation of the operating device R42 that it has detected to the remote controller R40. The remote controller R40 generates an operation signal based on the received information and transmits the generated operation signal to the shovel 100. The operating sensor R43 may be configured to generate the operation signal. In this case, the operating sensor R43 may output the operation signal to the communication device T2 without going through the remote controller R40. With this configuration, the remote operator RO can remotely operate the shovel 100 from the remote control room RC.

[0163] The remote controller R40, like the controller 30 of the first embodiment, includes an acquisition unit 301, a target trajectory acquisition unit 302, and an operation control unit 303. Therefore, the remote controller R40, like the controller 30 of the above-described embodiment, can cause the shovel 100 to operate autonomously.

[0164] Furthermore, the remote controller R40 can perform semi-automatic control when it receives an operation from the remote operator RO. In this case, the remote controller R40 generates a target trajectory for operating the attachment AT according to the received operation. Then, based on the difference between the predicted drilling reaction force estimated to occur in the attachment AT while drilling along the target trajectory and the drilling reaction force F detected while operating the attachment AT along the target trajectory, the remote controller R40 operates the attachment AT in a direction that reduces the drilling reaction force F if it is predicted that the reaction force estimated to occur in the attachment AT by the time the operation of the attachment AT along the target trajectory is completed will be greater than the critical reaction force Ft.

[0165] By having the configuration described above, the remote controller R40 can achieve the same control as the controller 30 in the embodiment described above.

[0166] The control center MC is a facility equipped with various devices for managing the remote operation of the excavator 100, either at the work site or by a remote operator RO in the remote control room RC. In the illustrated example, the control center MC is located at a distance from both the work site of the excavator 100 and the remote control room RC. The control center MC is equipped with a management device 200. The manager monitors the excavator 100 and issues instructions for autonomous operation to the excavator 100.

[0167] The management device 200 is an example of a control device, such as a server computer (a so-called cloud server) or an edge server. The management device 200 is typically a fixed terminal device, but it may also be a portable terminal device (for example, a laptop computer, tablet, or smartphone).

[0168] The control device 200 performs the same control as the remote controller R40 described above. For example, when the control device 200 receives an instruction for autonomous operation from the administrator, it controls the shovel 100 to perform the excavation work in accordance with that instruction. Then, in order to have the shovel 100 perform the excavation work, the control device 200 selects a target trajectory for excavation operation that is suitable for the soil shape, and based on the difference between the predicted excavation reaction force estimated to occur in the attachment AT while excavating along the target trajectory and the excavation reaction force F detected while operating the attachment AT along the target trajectory, if it is predicted that the reaction force estimated to occur in the attachment AT by the time the operation of the attachment AT along the target trajectory is completed will be greater than the limit reaction force Ft, the control device 200 operates the attachment AT in a direction that reduces the excavation reaction force F.

[0169] In this embodiment, the same effects as in the first embodiment can be obtained by having the remote controller R40 or the management device 200 perform the control described above.

[0170] <effect> In the embodiment described above, based on the shape of the soil around the shovel 100 and the target trajectory, a predicted excavation reaction force estimated to occur in the attachment AT while excavating according to the target trajectory is calculated. By operating the attachment AT in a direction that reduces the excavation reaction force F based on the predicted excavation reaction force, it is possible to suppress the attachment AT from stopping due to the excavation reaction force F during excavation and improve work efficiency.

[0171] In the above-described embodiment, based on the soil shape around the shovel 100 and the target trajectory, a predicted excavation reaction force estimated to occur in the attachment AT while excavating along the target trajectory is calculated. Based on the predicted excavation reaction force and the excavation reaction force F occurring in the attachment AT, which is obtained from the detection results of the cylinder pressure sensor while the attachment AT is operating along the target trajectory, the attachment AT is operated in a direction that reduces the excavation reaction force F. Therefore, in the above-described embodiment, by operating the attachment AT in a way that reduces the excavation reaction force F before the attachment AT stops due to the excavation reaction force F, the excavation operation can be continued while suppressing the reaching of the critical reaction force Ft. Thus, work efficiency can be improved.

[0172] In the above-described embodiment, when the shovel 100 performs an excavation operation, by avoiding the use of predicted excavation reaction force to stop the excavation, it is possible to continue the excavation work even if the material to be excavated is harder than expected, thereby improving work efficiency.

[0173] Preferred embodiments of the present disclosure have been described above. However, the inventions of the present disclosure are not limited to the embodiments described above. Various modifications, substitutions, etc., can be applied to the embodiments described above without departing from the scope of the inventions of the present disclosure. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not contradict each other technically. [Explanation of Symbols]

[0174] 100 Shovel 1. Lower running body 2. Swivel mechanism 3. Upper rotating body 4 Boom 5 Arms 6 buckets 7 Boom Cylinder 8 Arm Cylinder S1 Boom Angle Sensor S2 Arm Angle Sensor S3 Bucket Angle Sensor S5 Swivel Sensor S6 imaging device S7R Boom Rod Pressure Sensor S7B and boom bottom pressure sensor S8R Arm Rod Pressure Sensor S8B Arm Bottom Pressure Sensor S9R Bucket Rod Pressure Sensor S9B Bucket Bottom Pressure Sensor S10 spatial recognition device ST storage device LM pre-trained model ST1 Limit reaction force memory unit 30 controllers 301 Acquisition Department 302 Target trajectory acquisition section 1301 Selection Section 1302 Guessing Department 1303 Judgment section 1311 Lifting amount adjustment section 1312 Signal Output Section 1313 Excavation reaction force calculation unit 1314 Reaction force estimation unit RC Remote Control Room R40 Remote Controller 200 Management device

Claims

1. Lower running body and The lower traveling body is equipped with an upper slewing body that is rotatable, An attachment having a boom, arm, and end attachment, A control device that autonomously operates the attachment according to the target trajectory, The system includes a spatial recognition device that acquires information indicating the shape of objects around the shovel, The control device is Based on the soil shape around the shovel and the target trajectory, which are included in the information acquired by the spatial recognition device, the device calculates the predicted excavation reaction force that is estimated to occur in the attachment while excavating according to the target trajectory, and operates the attachment in a direction that reduces the excavation reaction force based on the predicted excavation reaction force. Shovel.

2. The control device operates the attachment in a direction that reduces the excavation reaction force when the predicted excavation reaction force is greater than a first reaction force defined as a criterion for stopping the operation of the attachment. The shovel according to claim 1.

3. The control device corrects the target trajectory so as to move the attachment in a direction that reduces the drilling reaction force when the calculated predicted drilling reaction force is greater than the first reaction force. The shovel according to claim 2.

4. Lower running body and The lower traveling body is equipped with an upper slewing body that is rotatable, An attachment having a boom, arm, and end attachment, A device for acquiring the drilling reaction force generated when drilling is performed with the aforementioned attachment, A control device that autonomously operates the attachment according to the target trajectory, The system includes a spatial recognition device that acquires information indicating the shape of objects around the shovel, The control device is Based on the soil shape around the shovel and the target trajectory, which are included in the information acquired by the spatial recognition device, a predicted excavation reaction force estimated to occur in the attachment while excavating along the target trajectory is calculated, and based on the predicted excavation reaction force and the excavation reaction force acquired by the device while operating the attachment along the target trajectory, the attachment is operated in a direction that reduces the excavation reaction force. Shovel.

5. The control device is Based on the difference between the predicted excavation reaction force and the actual excavation reaction force, if it is predicted that the reaction force estimated to occur in the attachment by the time the attachment finishes moving along the target trajectory will be greater than a first reaction force defined as the criterion for stopping the attachment's movement, the attachment will be moved in a direction that reduces the excavation reaction force. The shovel according to claim 4.

6. The control device is The target trajectory is obtained such that the predicted excavation reaction force does not exceed the first reaction force. The shovel according to claim 5.

7. The control device is Modify the target trajectory to include movement of the attachment in a direction that reduces the excavation reaction force, and operate the attachment along the modified target trajectory. The shovel according to claim 4.

8. The direction in which the excavation reaction force decreases is at least one of the following: the closing direction of the end attachment, the raising direction of the boom, and the closing or opening direction of the arm. A shovel according to any one of claims 1 to 7.

9. A shovel having a lower traveling body, an upper rotating body mounted on the lower traveling body so as to be rotatable, and an attachment having a boom, arm, and end attachment, A control device that autonomously operates the attachment according to the target trajectory, The device includes a spatial recognition device that acquires information indicating the shape of objects around the shovel, The control device calculates a predicted excavation reaction force estimated to occur in the attachment while excavating according to the target trajectory, based on the soil shape around the shovel and the target trajectory, which are included in the information acquired by the spatial recognition device, and operates the attachment in a direction that reduces the excavation reaction force based on the predicted excavation reaction force. Excavator control system.

10. A shovel comprising a lower traveling body, an upper rotating body mounted on the lower traveling body so as to be rotatable, an attachment having a boom, an arm, and an end attachment, and a device for acquiring the digging reaction force generated when digging is performed by the attachment, A control device that autonomously operates the attachment according to the target trajectory, The device includes a spatial recognition device that acquires information indicating the shape of objects around the shovel, The control device calculates a predicted excavation reaction force estimated to occur in the attachment while excavating along the target trajectory, based on the soil shape around the shovel and the target trajectory, which are included in the information acquired by the spatial recognition device, and operates the attachment in a direction that reduces the excavation reaction force, based on the predicted excavation reaction force and the excavation reaction force acquired by the device while operating the attachment along the target trajectory. Excavator control system.

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