Shovel and shovel control system

Abstract

This improves the precision of the attachment's operation. [Solution] A shovel according to one embodiment comprises a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, an attachment having a boom, an arm, and an end attachment, and a control device for operating the attachment. When the control device controls a first operation to move the attachment, if the amount of movement of a predetermined part of the attachment with respect to the displacement of a cylinder that operates the attachment is greater than that of a second operation in which the range of movement of the predetermined part differs from that of the first operation, the control device controls the first operation to reduce the speed of movement of the predetermined part compared to the second operation.

Description

Technical Field

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

Background Art

[0002] Conventionally, in order to perform work with an excavator, a technique has been proposed to control the operation of at least one of a boom cylinder and a bucket cylinder in accordance with the operation of an arm cylinder so that the working part of a bucket follows a target trajectory (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when operating a predetermined part of an attachment along a target trajectory, depending on the position of the attachment, the amount of movement of the predetermined part of the attachment may be larger than the displacement of the cylinder. In this case, due to the operation of the cylinder, the movement speed of the predetermined part of the attachment becomes high, so there is a problem that a position error is likely to occur.

[0005] In view of the above, it is realized to improve the accuracy of the operation of the attachment.

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, and a control device for operating the attachment, wherein when the control device controls a first operation to move the attachment, if the amount of movement of a predetermined part of the attachment with respect to the displacement of a cylinder that operates the attachment is greater than that of a second operation in which the range of movement of the predetermined part differs from that of the first operation, the control device controls the first operation to reduce the speed of movement of the predetermined part compared to the second operation.

[0007] 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, and a control device that autonomously operates the attachment based on a predetermined target trajectory, wherein the control device generates the target trajectory such that it does not include any intervals in which the value relating to the amount of movement of a predetermined part of the attachment with respect to the displacement of a cylinder that operates the attachment exceeds a predetermined threshold, and autonomously controls the attachment based on the target trajectory. [Effects of the Invention]

[0008] According to one aspect of the present invention, improved precision in the operation of the attachment is achieved. [Brief explanation of the drawing]

[0009] [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 amount of change in the tine position according to the posture of the shovel attachment 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 the correspondence between the displacement of the boom cylinder piston and the change in boom angle, as stored in the displacement memory unit according to the first embodiment. [Figure 6] This figure shows the correspondence between the displacement of the piston of the arm cylinder and the change in the angle of the arm, as stored in the displacement memory unit according to the first embodiment. [Figure 7] This figure shows the correspondence between the displacement of the bucket cylinder piston and the change in the bucket angle, as stored in the displacement memory unit according to the first embodiment. [Figure 8] This is an explanatory diagram showing a region in which the movement speed of the bucket's claws increases in response to the displacement in the boom cylinder and arm cylinder according to the first embodiment. [Figure 9] This is an explanatory diagram showing the region in which the movement speed of the bucket's claws increases in response to the displacement of the bucket cylinder according to the first embodiment. [Figure 10] This is a flowchart showing the processing procedure for autonomous operation of the attachment in the controller according to the first embodiment. [Figure 11] This figure illustrates speed control of a boom cylinder, arm cylinder, or bucket cylinder according to the first embodiment. [Figure 12] This is a flowchart showing the processing procedure for autonomous operation of the attachment in the controller according to the second embodiment. [Figure 13] This is an explanatory diagram illustrating the identification of a target trajectory to be used for motion control from a plurality of target trajectories by the controller according to the second embodiment. [Figure 14] This is a schematic diagram showing an example configuration of a remote control system according to the third embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The embodiments described below are illustrative and do not limit the invention. All features and combinations thereof in the embodiments of the present disclosure are not necessarily essential to the invention. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and redundant descriptions may be omitted.

[0011] The excavator 100 according to an embodiment of the present disclosure shows an example of a working machine. The excavator 100 according to the present embodiment is an excavator equipped with a bucket 6 as an end attachment, but may be an application machine having other configurations.

[0012] (First Embodiment) First, referring to FIG. 1, an overview of the excavator 100 according to the present embodiment will be described. FIG. 1 is a side view of the excavator 100 as a working machine according to the first embodiment.

[0013] +X in FIG. 1 represents one direction of the X-axis constituting a three-dimensional orthogonal coordinate system, and (not shown) -X represents the other direction of the X-axis. +Y represents one direction of the Y-axis constituting a three-dimensional orthogonal coordinate system, and (not shown) -Y represents the other direction of the Y-axis. +Z represents one direction of the Z-axis constituting a three-dimensional orthogonal coordinate system, and (not shown) -Z represents the other direction of the Z-axis. In FIG. 1, the +X side of the excavator 100 corresponds to the front side of the excavator 100, and the -X side of the excavator 100 corresponds to the rear side of the excavator 100. Also, the +Y side of the excavator 100 corresponds to the left side of the excavator 100, and the -Y side of the excavator 100 corresponds to the right side of the excavator 100. Further, the +Z side of the excavator 100 corresponds to the upper side of the excavator 100, and the -Z side of the excavator 100 corresponds to the lower side of the excavator 100. The same applies to other figures.

[0014] The excavator 100 includes a lower traveling body 1, an upper revolving body 3 mounted on the lower traveling body 1 so as to be revolvable via a revolving mechanism 2, an attachment AT for performing various operations, and a cab 10. The cab 10 is also called a cabin or a cab. The front side of the excavator 100 (upper revolving body 3) corresponds to the side where the attachment AT is attached to the upper revolving body 3 when the excavator 100 is viewed directly from above along the revolving axis of the upper revolving body 3. Also, the left side, right side, and rear side of the excavator 100 (upper revolving body 3) respectively correspond to the left side, right side, and rear side as viewed by an operator sitting on the driver's seat in the cab 10.

[0015] 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.

[0016] A boom 4 is rotatably attached to the center of the front part of the upper revolving 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 the attachment AT. The boom 4, the arm 5, and the bucket 6 are respectively driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9.

[0017] Bucket 6 is an example of a work tool (end attachment). Bucket 6 is used, for example, for excavation work. Depending on the work content, other work tools may be attached to the tip of arm 5 instead of bucket 6. Other work tools may be other types of buckets, such as large buckets, slope buckets, or dredging buckets. Other work tools may also be types of work tools other than buckets, such as agitators, breakers, grapples, or lifting magnets. The excavation attachment may be provided with a bucket tilt mechanism.

[0018] The slewing hydraulic motor 2A, the left travel hydraulic motor 2ML, the right travel hydraulic motor 2MR, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 are hydraulic actuators driven by hydraulic fluid discharged from a hydraulic pump.

[0019] Furthermore, the excavator 100 may have all or part of its driven parts, such as the lower traveling body 1, upper rotating body 3, boom 4, arm 5, and bucket 6, electrically driven. In other words, the excavator 100 may be a hybrid excavator or electric excavator in which all or part of its driven parts are driven by electric actuators.

[0020] The imaging device S6 is mounted on the upper rotating body 3 and captures images of the area around the shovel 100, acquiring image information representing the area around the shovel 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.

[0021] The front camera S6F is a camera that captures images in front of the shovel 100 and is mounted on the roof of the cab 10, the side of the boom 4, or other external locations on the cab 10. The left camera S6L is a camera that captures images to the left of the shovel 100, the right camera S6R is a camera that captures images to the right of the shovel 100, and the rear camera S6B is a camera that captures images behind the shovel 100. Specifically, the front camera S6F, left camera S6L, right camera S6R, and rear camera S6B are all monocular wide-angle cameras equipped with an image sensor such as a CCD or CMOS, and the information of the captured images is taken up by the controller 30. Alternatively, the images captured by the imaging device S6 may be output to the display device D1 (see Figure 2).

[0022] In the illustrated example, the front camera S6F is mounted on the roof of the driver's cab 10, the left camera S6L is mounted on the upper left end of the upper surface of the upper rotating body 3, the right camera S6R is mounted on the upper right end of the upper surface of the upper rotating body 3, and the rear camera S6B is mounted on the upper rear end of the upper surface of the upper rotating body 3.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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".

[0036] 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").

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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."

[0045] Figure 2 is a schematic diagram showing an example of the configuration of Excavator 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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.

[0064] [Differences in bucket tip position depending on the attachment's orientation] Next, with reference to Figure 3, the amount of change in the tip position of the shovel attachment according to the orientation of the shovel 100 according to this embodiment will be explained. Figure 3 is a conceptual diagram illustrating the amount of change in the tip position of the shovel attachment according to the orientation of the shovel 100 according to this embodiment.

[0065] The example shown in Figure 3(A) illustrates the change in position L1 of the tip 6a of the bucket 6 when the boom 4 is moved by an angle θ1 with the arm 5 in its maximum opening position.

[0066] The example shown in Figure 3(B) illustrates the change in position L2 of the tip 6a of the bucket 6 when the boom 4 is moved by an angle θ1 while the arm 5 is in a position between its maximum and minimum opening.

[0067] The examples shown in Figure 3(A) and Figure 3(B) each illustrate the case where the boom 4 is moved by an angle θ1, but the amount of change in the position of the bucket 6's tip 6a differs greatly depending on the attitude of the attachment AT. In other words, when the boom 4 is moved at a predetermined angular velocity in the attitude of the attachment AT shown in Figure 3(A), the bucket 6's tip 6a moves faster than when the boom 4 is moved at a predetermined angular velocity in the attitude of the attachment AT shown in Figure 3(B). The higher the speed of the tip 6a, the greater the potential for positional error. In other words, there is a possibility that the tip 6a will deviate from the target trajectory.

[0068] The situations in which such positional errors become large are not limited to the opening and closing state of arm 5, but change depending on the position of each of the boom cylinders: boom cylinder 7 which operates boom 4, arm cylinder 8 which operates arm 5, and bucket cylinder 9 which operates bucket 6. In other words, there are situations in which the movement speed of the toe tip 6a increases depending on the operation of the cylinders that operate the attachment AT (boom cylinder 7, arm cylinder 8, and bucket cylinder 9).

[0069] Therefore, when the controller 30 according to this embodiment performs a first operation to move the attachment AT, if the amount of movement of a predetermined part (e.g., the tip of the toe 6a) of the bucket 6 included in the attachment AT is greater than that of a second operation in which the range of movement of the predetermined part (e.g., the tip of the toe 6a) is different from that of the first operation, the controller 30 controls the first operation to reduce the speed of movement of the predetermined part (e.g., the tip of the toe 6a) compared to the second operation, in relation to the displacement of the cylinders that operate the attachment AT (each of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9).

[0070] [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.

[0071] 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. In this embodiment, the controller 30 has the following functional elements: an acquisition unit 301, a target trajectory generation unit 302, a determination unit 304, a speed adjustment unit 305, and an operation control unit 306. The controller 30 (an example of the control unit) according to this embodiment is configured to control the entire shovel 100. The memory device ST stores the displacement amount storage unit ST1.

[0072] The displacement memory unit ST1 stores the change in the angle of the boom 4 corresponding to the displacement of the boom cylinder 7, the change in the angle of the arm 5 corresponding to the displacement of the arm cylinder 8, and the change in the angle of the bucket 6 corresponding to the displacement of the bucket cylinder 9.

[0073] Figure 5 shows the correspondence between the displacement of the boom cylinder 7 piston and the change in the angle of the boom 4, as stored in the displacement memory unit ST1 according to this embodiment. The vertical axis represents the change in the angle of the boom 4, and the horizontal axis represents the displacement of the boom cylinder 7. As shown in Figure 5, the closer the piston of the boom cylinder 7 gets to the bottom or rod end of the boom cylinder 7, the larger the change in the angle of the boom 4 per unit displacement of the piston. And, the closer the piston of the boom cylinder 7 gets to the center connecting the bottom end and the rod end, the smaller the change in the angle of the boom 4 per unit displacement of the piston.

[0074] Figure 6 shows the correspondence between the displacement of the piston of the arm cylinder 8 and the change in the angle of the arm 5, as stored in the displacement amount storage unit ST1 according to this embodiment. The vertical axis represents the change in the angle of the arm 5, and the horizontal axis represents the displacement of the arm cylinder 8. As shown in Figure 6, the closer the piston of the arm cylinder 8 gets to the bottom or rod end of the arm cylinder 8, the larger the change in the angle of the arm 5 per unit displacement of the piston. And, the closer the piston of the arm cylinder 8 gets to the center connecting the bottom end and the rod end, the smaller the change in the angle of the arm 5 per unit displacement of the piston.

[0075] Figure 7 shows the correspondence between the displacement of the piston of the bucket cylinder 9 and the change in the angle of the bucket 6, as stored in the displacement memory unit ST1 according to this embodiment. The vertical axis represents the change in the angle of the bucket 6, and the horizontal axis represents the displacement of the bucket cylinder 9. As shown in Figure 7, the closer the piston of the bucket cylinder 9 gets to the bottom or rod end of the bucket cylinder 9, the larger the change in the angle of the bucket 6 per unit displacement of the piston. And, the closer the piston of the bucket cylinder 9 gets to the center connecting the bottom end and the rod end, the smaller the change in the angle of the bucket 6 per unit displacement of the piston.

[0076] The correspondence between the piston displacement shown in Figures 5 to 7 and the angular changes of each component of the attachment AT can be derived using any method. For example, a Jacobian matrix may be used to represent this correspondence. Specifically, a matrix is ​​derived that represents the effect on each component of the pin position of each component of the attachment AT when the piston position is moved slightly, and based on this matrix, the amount of angular change of each component of the attachment AT per unit displacement of the piston is calculated. Then, before shipping the shovel 100, the amount of angular change of each component of the attachment AT per unit displacement of the piston is stored in the displacement amount storage unit ST1.

[0077] Figure 8 is an explanatory diagram showing the region in this embodiment in which the movement speed of the bucket's toe 6a increases in response to the displacement of the boom cylinder 7 and the arm cylinder 8. Region 1801 shown in Figure 8 is a region in which, depending on the relationship between the amount of angular change of each component of the attachment AT corresponding to the cylinder displacement and the distance between each component of the attachment AT and a predetermined part, when at least one of the boom cylinder 7 and the arm cylinder 8 moves by a predetermined amount of displacement (per unit time), the movement speed of the bucket's toe 6a becomes faster than a predetermined standard speed. In this embodiment, the controller 30 controls the movement speed to reduce it when, for example, the toe 6a is in region 1801.

[0078] In this embodiment, the controller 30 may control the movement speed according to the position of the tip 6a of the bucket 6. For example, within the range in which the tip 6a of the bucket 6 can move, region 1801 is defined as a region where the movement speed of the tip 6a of the bucket 6 is faster than that of the cylinder displacement. In other words, region 1801 is a region where positional errors of the tip 6a are likely to occur.

[0079] As a variation, the controller 30 determines whether or not the bucket 6 is in area 1801, and if it is determined that the bucket 6 is in area 1801, it controls the movement speed to be reduced.

[0080] On the other hand, within the range in which the bucket 6 can move, the region other than region 1801 is defined as a region where the movement speed of the bucket 6's claw 6a is low relative to the displacement of the cylinder. In other words, the region other than region 1801 is a region where positional errors of the claw 6a are less likely to occur.

[0081] Therefore, as a variation, if the controller 30 determines that the bucket 6 is in an area other than area 1801, it may control it at a faster movement speed than when it is in area 1801.

[0082] Figure 9 is an explanatory diagram showing the region in which the movement speed of the bucket's claw 6a increases in response to the displacement of the bucket cylinder 9 according to this embodiment. In the example shown in Figure 9, the movement range from bucket 6(61) to bucket 6(62) is defined by the operation of the bucket cylinder 9. The claw 6a of the bucket 6 is then made movable between regions 1901, 1902, and 1903 by the operation of the bucket cylinder 9.

[0083] Regions 1901 and 1903 shown in Figure 9 are near the rod-side or bottom-side end of the bucket cylinder 9, so the amount of movement of the bucket's claw 6a per unit displacement of the bucket cylinder 9 is large. In other words, near the stroke end of the bucket 6, the amount of movement of the bucket's claw 6a per unit displacement of the bucket cylinder 9 is large.

[0084] On the other hand, since region 1902 is near the center connecting the rod-side end and the bottom-side end of the bucket cylinder 9, the amount of movement of the tip 6a of the bucket 6 per unit displacement of the bucket cylinder 9 becomes small.

[0085] In other words, when the toe 6a is located in regions 1901 and 1903, the movement speed of the toe 6a of the bucket 6, in accordance with the displacement of the bucket cylinder 9, is faster than when the toe 6a is located in region 1902.

[0086] Therefore, the controller 30 may, for example, control the movement speed to reduce it if the toe 6a is present in areas 1901 and 1903, even if it is determined that the bucket 6 is in an area other than area 1801. Next, the specific control of the controller 30 according to this embodiment will be described.

[0087] 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.

[0088] 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.

[0089] 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 attachment AT, semi-automatic control may be performed to operate at least one of the boom 4, arm 5, and bucket 6 so that a predetermined part of the attachment AT (for example, the tip 6a of the bucket 6) moves along a target trajectory.

[0090] 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.

[0091] The target trajectory generation unit 302 generates a target trajectory, which is the trajectory that a predetermined part of the attachment AT (for example, the tip 6a of the bucket 6) will follow when the shovel 100 is operated autonomously, based on the shape of the soil around the shovel 100 detected by the spatial recognition device S10 (acquired by the acquisition unit 301) and the target construction surface stored in the storage device ST. Any method may be used for generating the target trajectory; for example, a method may be used in which multiple target trajectories are prepared in advance and selected from among them. In this embodiment, since the target trajectory is generated based on the shape of the soil and the target construction surface, autonomous operation according to the current situation is possible, thereby improving work efficiency.

[0092] Furthermore, when the target trajectory generation unit 302 generates a target trajectory, a first target speed is set for each of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 in order to operate them so that a predetermined part moves along the target trajectory. The first target speed can be set using the same method as in the conventional method, so no further explanation is provided.

[0093] The calculation unit 303 calculates an evaluation value for each section of the target trajectory generated by the target trajectory generation unit 302, where the target trajectory is divided into predetermined intervals, showing the amount of displacement of a predetermined part of the attachment AT (for example, the toe 6a of the bucket 6) in relation to the displacement of cylinders 7 to 9 in that section. In this embodiment, the calculation unit 303 calculates the evaluation value Vtotal for that section using the following formula (1). Vboom is the amount of angular change of boom 4 corresponding to the displacement of the piston of boom cylinder 7, Varm is the amount of angular change of arm 5 corresponding to the displacement of the piston of arm cylinder 8, and Vbucket is the amount of angular change of bucket 6 corresponding to the displacement of the piston of bucket cylinder 9. L11 is the length from the axis (foot pin) of boom 4 to the toe 6a, and L12 is the length from the axis of arm 5 to the toe 6a. L11 and L12 are derived from the detection results of angle sensors S1 to S3 and the lengths of each component of the attachment AT. Also, w1 to w5 are weights determined according to the embodiment.

[0094] Vtotal=w1×Vboom^2+w2×Varm^2+w3×Vbucket^2+w4×L11^2+w5×L12^2……(1)

[0095] This embodiment describes an example in which the evaluation value Vtotal is calculated based on the angular change of each component of the attachment AT corresponding to the displacement of the cylinder, and the distance between each component of the attachment AT and a predetermined part (e.g., the toe 6a). This embodiment does not limit the method for calculating the evaluation value Vtotal to the example using equation (1). For example, the evaluation value Vtotal may be calculated only from the angular change of each component of the attachment AT corresponding to the displacement of the cylinder.

[0096] The determination unit 304 determines whether the evaluation value Vtotal calculated for each interval by the calculation unit 303 is greater than a predetermined threshold Th. The threshold Th is a value determined according to the embodiment.

[0097] The speed adjustment unit 305 adjusts the target speed of at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 according to the determination result by the determination unit 304.

[0098] For example, when operating the boom cylinder 7 so that the toe 6a moves along the target trajectory in a predetermined section of the target trajectory, if the determination unit 304 determines that the evaluation value Vtotal is greater than a predetermined threshold in that predetermined section, the speed adjustment unit 305 controls the target speed for operating the boom cylinder 7 to be lower than the first target speed. For example, if the evaluation value Vtotal is determined to be greater than a predetermined threshold, the speed adjustment unit 305 controls the target speed for moving the piston of the boom cylinder 7 to be a second target speed lower than the first target speed. The second target speed is a predetermined speed depending on the embodiment.

[0099] The motion control unit 306 controls the attachment AT so that a predetermined part of the attachment AT moves along the target trajectory generated by the target trajectory generation unit 302. In this case, the motion control unit 306 controls at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 to reach a second target speed adjusted by the speed adjustment unit 305 in the section where the determination unit 304 determines that the evaluation value Vtotal is greater than the threshold. On the other hand, the motion control unit 306 controls at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 to reach a predetermined first target speed in the section where the determination unit 304 determines that the evaluation value Vtotal is less than or equal to the threshold.

[0100] The processing procedure performed by the controller 30 according to this embodiment will now be described. Figure 10 is a flowchart showing the processing procedure for autonomous operation of the attachment AT in the controller 30 according to this embodiment.

[0101] First, the acquisition unit 301 acquires the shape of the soil surrounding the shovel 100 from the detection results of the spatial recognition device S10 (S2001).

[0102] The target trajectory generation unit 302 generates a target trajectory based on the shape of the soil and other elements around the shovel 100 detected by the spatial recognition device S10, and sets a first target speed for each of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 so that predetermined parts move along the target trajectory (S2002).

[0103] The calculation unit 303 calculates an evaluation value Vtotal for each section of the target trajectory divided at predetermined intervals, which represents the amount of displacement of a predetermined part of the attachment AT (for example, the tip 6a of the bucket 6) in relation to the displacement of the cylinders 7 to 9 (S2003).

[0104] The determination unit 304 determines whether the evaluation value Vtotal calculated for the section included in the target trajectory is greater than the threshold Th (S2004). The determination unit 304 performs the determination starting from the section of the target trajectory corresponding to the starting position. If the evaluation value Vtotal calculated for that section is determined to be less than or equal to the threshold Th (S2004: NO), processing proceeds from S2006.

[0105] On the other hand, if the determination unit 304 determines that the evaluation value Vtotal is greater than the threshold Th (S2004: YES), the speed adjustment unit 305 adjusts the speed of each of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 from a first target speed to a second target speed that is lower than the first target speed (S2005).

[0106] The determination unit 304 determines whether the determination has been completed for all sections (S2006). If it determines that the determination has not been completed for all sections (S2006: NO), it changes the target to the next section (S2007) and processes again from S2004.

[0107] On the other hand, if the determination unit 304 determines that it has completed the determination for all sections (S2006: YES), the operation control unit 306 controls the operation of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 respectively so that they reach the target speed (first target speed or second target speed) set for each section in order to move the predetermined part along the target trajectory (S2007).

[0108] Figure 11 illustrates the speed control of the boom cylinder 7, arm cylinder 8, or bucket cylinder 9 according to this embodiment. Line 2101 in Figure 11(A) shows the change in height of the tip 6a of the bucket 6 according to the distance traveled in the horizontal plane. A target trajectory is generated such that the tip 6a of the bucket 6 moves to a lower position according to the distance traveled in the horizontal plane.

[0109] In Figure 11(A), of the travel distances shown, interval 2111 is the interval in which the evaluation value Vtotal is determined to be greater than the threshold Th, and interval 2112 is the interval in which the evaluation value Vtotal is determined to be less than or equal to the threshold Th.

[0110] Figure 11(B) shows the operating speed of the boom cylinder, arm cylinder, or bucket cylinder in a conventional excavator when a predetermined part of the attachment is controlled to follow a target trajectory. As shown by line 2102 in Figure 11(B), when the operating speed of the boom cylinder, arm cylinder, or bucket cylinder is constant, in the interval 2111 where the evaluation value Vtotal exceeds the threshold Th, the movement speed of the predetermined part increases, which may cause positional errors.

[0111] Line 2103 in Figure 11(C) shows the operating speed of the boom cylinder 7, arm cylinder 8, or bucket cylinder 9 in the excavator 100 according to this embodiment when a predetermined part of the attachment AT (for example, the tip 6a of the bucket 6) is controlled to follow a target trajectory. In the example shown in Figure 11(C), in section 2111, the boom cylinder, arm cylinder, or bucket cylinder moves at a second target speed v2. Then, from the travel distance Lt where it switches to section 2112, the controller 30 increases the speed of the boom cylinder 7, arm cylinder 8, or bucket cylinder 9. After that, the boom cylinder 7, arm cylinder 8, or bucket cylinder 9 moves at a first target speed v1.

[0112] In other words, the controller 30 sequentially performs control to operate at a second target speed in section 2111 and control to operate at a first target speed in section 2112. This allows the controller to control the operation so as to reduce the movement speed of a predetermined part of the attachment AT when the amount of movement of that predetermined part becomes large in relation to the displacement of the cylinders 7, 8, and 9 that operate the attachment AT. Therefore, the controller 30 according to this embodiment can suppress positional errors in the predetermined part of the attachment AT and improve the accuracy of the operation of the attachment AT.

[0113] Furthermore, this embodiment does not limit the start of target speed switching to the timing when the section changes. For example, the speed may already be increased at the timing when the section changes, or the speed increase may already be completed at the timing when the section changes, and movement may start at the first target speed v1. Moreover, this embodiment is not limited to a configuration in which an evaluation value is calculated for each section in which the target trajectory is divided at predetermined intervals, and the target speed is adjusted based on the evaluation value. The controller 30 may adjust the target speed of the boom cylinder 7, arm cylinder 8, or bucket cylinder 9 without dividing the target trajectory into sections. When the controller 30 controls the first operation to move the attachment AT, if the amount of movement of a predetermined part of the bucket 6 (e.g., the toe 6a) with respect to the displacement of the cylinder that operates the attachment AT is greater than that of a second operation in which the range of movement of the predetermined part (e.g., the toe 6a) is different, it is sufficient to control the first operation so as to reduce the movement speed of the predetermined part of the bucket 6 (e.g., the toe 6a) compared to the second operation. For example, the controller 30 may control the target speed based on the change in height of the tip 6a of the bucket 6 in proportion to the distance traveled in the horizontal plane, as shown by line 2101 in Figure 11(A). More specifically, the controller 30 may control the target speed to increase as the change in height in proportion to the distance traveled decreases.

[0114] The controller 30 according to this embodiment can suppress positional errors at predetermined locations by adjusting the target speed of the boom cylinder 7, arm cylinder 8, or bucket cylinder 9, as described above.

[0115] (Second embodiment) In the embodiments described above, an example of adjusting the target speed to suppress positional errors was explained. However, the embodiments described above do not limit the method of adjusting the target speed to suppress positional errors. Therefore, in the second embodiment, an example of changing the target trajectory to suppress positional errors will be described. In this embodiment, the shovel 100 has the same configuration as in the embodiments described above, and is assigned the same reference numerals, and its description is omitted.

[0116] In this embodiment, the target trajectory generation unit 302 generates a target trajectory based on the shape of the soil around the shovel 100 detected by the spatial recognition device S10 and the target construction surface stored in the storage device ST, such that the evaluation value (an example of a value) Vtotal, which relates to the amount of movement of a predetermined part of the attachment AT in relation to the displacement of the cylinder that operates the attachment AT, does not include any section in which the trajectory does not exceed the threshold Th. The operation control unit 306 then performs autonomous control of the attachment AT based on the target trajectory. Next, a specific method will be described.

[0117] For example, the target trajectory generation unit 302 has a combination of the position where the bucket 6 starts excavating, the position where excavation is completed, and the depth to which excavation is performed, relative to the shape of the soil, and generates multiple target trajectories from these combinations. Each of the generated target trajectories is set so that the amount of soil loaded into the bucket 6 is a predetermined amount corresponding to the bucket 6. In this embodiment, since the target trajectory is generated based on the shape of the soil, autonomous operation according to the current situation is possible, thereby improving work efficiency.

[0118] For each of the multiple target trajectories generated, the calculation unit 303 calculates an evaluation value Vtotal for each section obtained by dividing the target trajectory at predetermined intervals, which represents the amount of displacement of a predetermined part of the attachment AT (for example, the tip 6a of the bucket 6) in relation to the displacement of the cylinders 7 to 9 in that section.

[0119] The determination unit 304 then identifies a target trajectory from each of the multiple target trajectories such that the evaluation value Vtotal calculated for each section does not include any section in which the evaluation value Vtotal exceeds the threshold Th.

[0120] The specific identification method may be determined according to the embodiment. For example, if there is only one target trajectory among several target trajectories in which the evaluation value Vtotal for all sections is less than or equal to the threshold Th, then the target trajectory may be selected.

[0121] Furthermore, if there are multiple target trajectories where the evaluation value Vtotal for all segments is less than or equal to the threshold Th, the target trajectory that yields the smallest evaluation value Vtotal for the highest segment calculated from each of these target trajectories may be identified. Alternatively, the target trajectory that yields the lowest total evaluation value Vtotal for all segments calculated from each of the multiple target trajectories may be identified.

[0122] If, among the multiple target trajectories, there is no target trajectory in which the evaluation value Vtotal for all sections is less than or equal to the threshold Th, in other words, if all target trajectories include a section in which the evaluation value Vtotal is greater than the threshold Th, then a target trajectory may be regenerated that does not include a section in which the evaluation value Vtotal is greater than the threshold Th. Specifically, the load amount of the bucket 6 may be adjusted (for example, reduced), and then the target trajectory generation unit 302 may generate multiple target trajectories again, and the above-described control may be performed again on the generated multiple target trajectories.

[0123] Alternatively, if there is no target trajectory among multiple target trajectories in which the evaluation value Vtotal for all sections is less than or equal to the threshold Th, the determination unit 304 may identify one target trajectory from among the multiple target trajectories. For example, the determination unit 304 may identify the target trajectory among multiple target trajectories in which the number of sections in which the evaluation value Vtotal is greater than the threshold Th is smallest. Then, for the sections in the identified target trajectory in which the evaluation value Vtotal is greater than the threshold Th, the speed adjustment unit 305 may adjust the target speed of at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9, similar to the embodiment described above.

[0124] The motion control unit 306 controls the attachment AT to move a predetermined part of the attachment AT along a specified target trajectory. In doing so, the motion control unit 306 controls at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 to reach the first target speed, unless it is a section adjusted to the second target speed by the speed adjustment unit 305.

[0125] The processing procedure performed by the controller 30 according to this embodiment will now be described. Figure 12 is a flowchart showing the processing procedure for autonomous operation of the attachment AT in the controller 30 according to this embodiment.

[0126] 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 (S2201).

[0127] The target trajectory generation unit 302 generates multiple target trajectories based on the shape of the soil and other elements around the shovel 100 detected by the spatial recognition device S10 (S2202).

[0128] The calculation unit 303 calculates an evaluation value Vtotal for each of the multiple target trajectories, for each section of the target trajectory divided at predetermined intervals, which represents the amount of displacement of a predetermined part of the attachment AT (for example, the tip 6a of the bucket 6) in relation to the displacement of the cylinders 7 to 9 (S2203).

[0129] The determination unit 304 identifies the target trajectory to be used for motion control based on the evaluation value Vtotal calculated for each section in each of the multiple target trajectories (S2204).

[0130] Subsequently, the motion control unit 306 controls the operation of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 respectively so that they move along the specified target trajectory (S2205).

[0131] Figure 13 is an explanatory diagram illustrating the identification of a target trajectory used for motion control from a plurality of target trajectories by the controller 30 according to this embodiment. In the example shown in Figure 13, a first target trajectory 2301 and a second target trajectory 2302 are generated by the target trajectory generation unit 302 as target trajectories in which the amount of soil loaded corresponds to a predetermined amount corresponding to the bucket 6.

[0132] The calculation unit 303 then calculates an evaluation value Vtotal for each of the multiple target trajectories 2301 and 2302, for each section in which the target trajectory is divided at predetermined intervals. The determination unit 304 then identifies the first target trajectory 2301 to be used for operation control based on the calculated evaluation value Vtotal for each section. In other words, the second target trajectory 2302 is determined to have a section in which the evaluation value Vtotal is greater than the threshold Th in order to operate at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 near the bottom or rod end. On the other hand, the first target trajectory 2301 is determined to have no section in which the evaluation value Vtotal is greater than the threshold Th.

[0133] Therefore, the motion control unit 306 according to this embodiment controls the movement of a predetermined part of the attachment AT along the first target trajectory 2301. This control helps to suppress positional errors.

[0134] This embodiment describes a method by which the target trajectory generation unit 302 generates a target trajectory such that the evaluation value (an example of a value) Vtotal, which relates to the amount of movement of a predetermined part of the attachment AT with respect to the displacement of the cylinder that operates the attachment AT, does not include any intervals in which the evaluation value for each interval does not include any intervals in which the evaluation value for each interval exceeds the threshold Th. As a modification, the target trajectory generation unit 302 may generate a target trajectory such that the sum of the Vtotal values ​​for all intervals is less than a predetermined threshold. Thus, the target trajectory generation unit 302 may use any method that can generate a target trajectory in which the value relating to the amount of movement of a predetermined part of the attachment AT with respect to the displacement of the cylinder that operates the attachment AT is less than a predetermined threshold.

[0135] (Modification 1 of the second embodiment) In the second embodiment, an example was described in which multiple target trajectories are generated and a target trajectory to be used for motion control is identified from among the multiple target trajectories. However, the second embodiment does not limit the method for generating target trajectories to the procedure shown in the second embodiment.

[0136] Therefore, in the modified example 1 of the second embodiment, an example in which the operator sets the target trajectory will be described. The operator inputs the target trajectory, for example, from the input device D2 provided in the driver's cab 10. The acquisition unit 301 of the controller 30 then acquires information indicating the input target trajectory.

[0137] The calculation unit 303 calculates an evaluation value Vtotal for each section of the target trajectory indicated in the acquired information. The determination unit 304 then determines whether the evaluation value Vtotal calculated for each section is greater than the threshold Th. If the determination unit 304 determines that there is a section in which the evaluation value Vtotal is greater than the threshold Th, the target trajectory generation unit 302 generates a modified target trajectory based on the target trajectory indicated in the acquired information, so as not to include any sections in which the evaluation value Vtotal is greater than the threshold Th.

[0138] This corrects the target trajectory so that at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 does not include a section in which it operates near the bottom or rod end.

[0139] In this modified example, even when the operator inputs the target trajectory, the positional error in the designated part of the attachment AT can be suppressed by correcting the target trajectory as described above, thereby improving the accuracy of the attachment AT's operation.

[0140] (Modification 2 of the second embodiment) The second embodiment and Modification 1 of the second embodiment illustrate an example of a method for generating a target trajectory such that the trajectory does not include a region where the evaluation value Vtotal is greater than the threshold Th. Next, Modification 2 of the second embodiment describes another mode in which the target trajectory is generated such that the trajectory does not include a region where the evaluation value Vtotal is greater than the threshold Th.

[0141] In the modified example 2 of the second embodiment, the target trajectory generation unit 302 has in advance multiple target trajectories that do not include regions in the trajectory where the evaluation value Vtotal for each section is greater than the threshold Th. The target trajectory generation unit 302 then selects a target trajectory from the multiple target trajectories that correspond to the surrounding soil shape and the target construction surface.

[0142] In this modified example as well, since the target trajectory used for motion control is identified as such that the evaluation value Vtotal for each section does not include a region where the trajectory is greater than the threshold Th, the same effects as in the second embodiment can be obtained.

[0143] (Third embodiment) A third embodiment describes a case in which a remote system for operating the shovel 100 is provided.

[0144] Next, with reference to Figure 14, an example configuration of the remote control system (an example of a control system) SYS according to the third embodiment will be described. Figure 14 is a schematic diagram showing an example configuration of the remote control system SYS according to the third embodiment. As shown in Figure 14, 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 14 because the shovel 100 shown in Figure 14 has the same configuration as the shovel 100 shown in Figure 1.

[0145] 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.

[0146] For example, the shovel 100 transmits image information captured by the imaging device S6 to the remote control room RC.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] The communication device T2 is configured to communicate with the communication device T1 attached to the shovel 100.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] The remote controller R40, like the controller 30 of the first embodiment, includes an acquisition unit 301, a target trajectory generation unit 302, a calculation unit 303, a determination unit 304, a speed adjustment unit 305, and an operation control unit 306. Therefore, the remote controller R40, like the controller 30 of the above-described embodiment, can cause the shovel 100 to operate autonomously.

[0155] In other words, similar to the first embodiment, when the remote controller R40 performs a first operation to move the attachment AT, if the amount of movement of a predetermined part (e.g., the tip 6a) of the bucket 6 included in the attachment AT is greater than that of a second operation in which the range of movement of the predetermined part (e.g., the tip 6a) is different from that of the first operation, the remote controller R40 can control the first operation to reduce the movement speed of the predetermined part (e.g., the tip 6a) compared to the second operation. The remote controller R40 may also control the operation of the shovel 100 by other methods.

[0156] Alternatively, the target trajectory generation unit 302 of the remote controller R40 may generate a target trajectory based on the shape of the soil around the shovel 100 detected by the spatial recognition device S10 and the target construction surface stored in the memory device ST, such that the trajectory does not include a region where the evaluation value Vtotal, which relates to the amount of movement of a predetermined part of the attachment AT in relation to the displacement of the cylinder that operates the attachment AT, is greater than the threshold Th. The operation control unit 306 may then perform autonomous control of the attachment AT based on the target trajectory.

[0157] By having the configuration described above, the remote controller R40 can achieve the same control as the controller 30 in the embodiment described above.

[0158] 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.

[0159] 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).

[0160] The control device 200 performs the same control as the remote controller R40 described above. In other words, the control device 200 controls the autonomous operation of the shovel 100, just like the remote controller R40.

[0161] In this embodiment, the same effects as in the first and second embodiments can be obtained by having the remote controller R40 or the management device 200 perform the control described above.

[0162] <effect> In the above-described embodiment, when the amount of movement of a predetermined part of the attachment AT becomes large in relation to the displacement of the cylinders 7, 8, and 9 that operate the attachment AT, the operation is controlled to reduce the movement speed of the predetermined part, thereby suppressing positional errors in the predetermined part of the attachment AT and improving the accuracy of the operation of the attachment AT.

[0163] In the embodiment described above, a target trajectory is generated such that it does not include a region where the movement speed of a predetermined part of the attachment AT increases, and the attachment AT is autonomously controlled based on this target trajectory. This suppresses positional errors in the predetermined part of the attachment AT and improves the accuracy of the attachment AT's operation.

[0164] 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]

[0165] 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 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 ST1 Displacement Amount Storage Unit 30 controllers 301 Acquisition Department 302 Target trajectory generation unit 303 Calculation Unit 304 Judgment section 305 Speed ​​adjustment section 306 Operation Control 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, The system comprises a control device for operating the aforementioned attachment, The control device is When controlling the first operation to move the attachment, if the amount of movement of a predetermined part of the attachment with respect to the displacement of the cylinder that operates the attachment is greater than that of the second operation in which the range of movement of the predetermined part differs from that of the first operation, the first operation is controlled to reduce the speed of movement of the predetermined part compared to the second operation. Shovel.

2. The control device controls the first operation and the second operation in sequence, so that when moving the attachment based on a predetermined target trajectory, it controls the first operation to reduce the movement speed of the predetermined part compared to the second operation. The shovel according to claim 1.

3. The device further includes a spatial recognition device that acquires information indicating the shape of objects surrounding the shovel. The control device generates a target trajectory based on the shape of the soil surrounding the shovel, and moves the attachment along the target trajectory by sequentially controlling the first operation and the second operation. 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, The system includes a control device that autonomously operates the attachment based on a predetermined target trajectory, The control device generates a target trajectory such that the value relating to the amount of movement of a predetermined part of the attachment with respect to the displacement of the cylinder that operates the attachment is smaller than a predetermined threshold, and performs autonomous control of the attachment based on the target trajectory. Shovel.

5. A predetermined threshold is set for each section that divides the target trajectory. The control device generates the target trajectory such that it does not include any intervals in which the value relating to the amount of movement of a predetermined part of the attachment with respect to the displacement of the cylinder that operates the attachment exceeds the predetermined threshold. The shovel according to claim 4.

6. When the control device receives input of information indicating the target trajectory, it modifies the target trajectory such that the value relating to the amount of movement of a predetermined part of the attachment with respect to the displacement of the cylinder that operates the attachment becomes smaller than the predetermined threshold. The shovel according to claim 4.

7. The device further includes a spatial recognition device that acquires information indicating the shape of objects surrounding the shovel. The control device identifies a target trajectory from a plurality of target trajectories generated based on the shape of the soil around the shovel such that the value is smaller than a predetermined threshold. The shovel according to claim 4.

8. 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, The system comprises a control device for operating the aforementioned attachment, When the control device controls the first operation to move the attachment, if the amount of movement of a predetermined part of the attachment with respect to the displacement of the cylinder that operates the attachment is greater than that of the second operation in which the range of movement of the predetermined part differs from that of the first operation, the control device controls the first operation to reduce the speed of movement of the predetermined part compared to the second operation. Excavator control system.

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, The system includes a control device that autonomously operates the attachment based on a predetermined target trajectory, The control device generates a target trajectory such that the value relating to the amount of movement of a predetermined part of the attachment with respect to the displacement of the cylinder that operates the attachment is smaller than a predetermined threshold, and performs autonomous control of the attachment based on the target trajectory. Excavator control system.

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