Shovel

Abstract

To improve work efficiency. [Solution] An excavator according to one embodiment includes an attachment and a control device that switches the control of the operation of the attachment depending on the posture of the attachment when the operation of the attachment stops while the attachment is performing excavation.

Description

Technical Field

[0001] The present invention relates to an excavator.

Background Art

[0002] Conventionally, a technique for operating an attachment according to the load generated on the attachment while working with an excavator has been proposed. For example, a technique has been proposed to drive the boom to rise when the load detected during automatic excavation of the excavator exceeds a set value (see 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, during excavation work, when the operation of the attachment stops due to the load generated on the attachment, simply performing uniform control may make it difficult to operate the attachment because the load application condition by earth and sand etc. differs according to the posture of the attachment.

[0005] In view of the above, by switching the control of the operation according to the posture of the attachment, the operation of the attachment is facilitated and the work efficiency is improved.

Means for Solving the Problems

[0006] An excavator according to one aspect of the present invention includes an attachment and a control device that switches the control of the operation of the attachment according to the posture of the attachment when the operation of the attachment stops while excavating with the attachment.

Effects of the Invention

[0007] According to one aspect of the present invention, the operation of the attachment is facilitated, 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 load during excavation operation in a shovel according to the first embodiment. [Figure 4] This is a conceptual diagram illustrating the load during excavation operation in a shovel according to the first embodiment. [Figure 5] This is an explanatory diagram showing an example of controlling the operation of an attachment using the controller according to the first embodiment when the angle of the arm with respect to the horizontal plane is less than 290 degrees. [Figure 6] This is an explanatory diagram showing an example of controlling the operation of an attachment using the controller according to the first embodiment when the angle of the arm with respect to the horizontal plane is greater than 290 degrees. [Figure 7] This is a flowchart showing the processing procedure for excavation operation by autonomous control of the controller according to the first embodiment. [Figure 8] This is a flowchart showing the processing procedure for excavation operation by autonomous control of the controller according to the second embodiment. [Figure 9] This is a flowchart showing the processing procedure for excavation operation by autonomous control of the controller according to the third 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 work machine. In the illustrated example, the shovel 100 is an excavator equipped with a bucket 6 as an end attachment, but it may also be an applied machine such as a forestry machine equipped with an end attachment other than the bucket 6.

[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 travel 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 travel hydraulic motor 2ML (see Figure 2), and the right crawler is driven by a right travel hydraulic motor 2MR (see Figure 2). The left travel hydraulic motor 2ML is a travel drive unit that drives the left crawler, which is the driven part, and can rotate the left crawler. The right travel hydraulic motor 2MR is a travel drive unit that drives the right crawler, which is the driven part, and can rotate the right crawler. Note that the travel drive units may also be electric motors.

[0015] A boom 4 is rotatably mounted to the front center of the upper slewing body 3, an arm 5 is rotatably mounted to the tip of the boom 4, and a bucket 6 is rotatably mounted to the tip of the arm 5. In the illustrated example, the boom 4, arm 5, and bucket 6 constitute an excavation attachment, which is an example of attachment AT. The boom 4, arm 5, and bucket 6 are driven by a boom cylinder 7, arm cylinder 8, and 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, a dredging bucket, etc. Further, the other working tools may be working tools of types 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] The swing 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 oil discharged from a hydraulic pump.

[0018] Note that all or part of the driven parts such as the lower traveling body 1, the upper swing 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 swing 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 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).

[0021] 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.

[0022] The imaging device S6 may constitute an object detection device that detects objects in the vicinity of the shovel 100. The object detection device may consist of devices other than a camera. For example, the object detection device may be a LiDAR. A LiDAR is, for example, a device capable of measuring the distance between a point cloud of 1 million or more points within the monitoring range and the LiDAR (laser source). Alternatively, the object detection device may be other devices capable of measuring the distance to an object, such as a stereo camera, a depth image camera, or a millimeter-wave radar. When a millimeter-wave radar or the like is used as the object detection device, the object detection device may derive the distance and direction of the object by transmitting a large number of signals (such as laser light) toward the object and receiving the reflected signals. Alternatively, the object detection device may be a combination of two or more types of devices. For example, the object detection device may be a combination of an imaging device and a LiDAR, a combination of an imaging device and a millimeter-wave radar, or a combination of an imaging device and a stereo camera.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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".

[0032] 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").

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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."

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] Furthermore, as shown in Figure 2, the control system of the shovel 100 includes a controller 30, an auxiliary storage device ST, a display device D1, an input device D2, and a communication device T1, etc.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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).

[0058] The auxiliary storage device ST is a read-write, non-volatile storage medium. The auxiliary storage device ST stores, for example, information indicating a predetermined target design surface (hereinafter simply referred to as "design surface").

[0059] [Explanation of load during excavation operation] Next, we will explain the load on the shovel 100 during excavation. Figures 3 and 4 are conceptual diagrams illustrating the load on the shovel 100 during excavation according to this embodiment.

[0060] Figure 3 illustrates a situation where the excavation operation by attachment AT has stopped due to hard soil. In the example shown in Figure 3, the angle of arm 5 with respect to the horizontal plane 1310 is less than 290 degrees. In this case, a load is generated on bucket 6 in the direction of arrow 1301. The controller 30 then determines, based on the cylinder pressure detected by cylinder pressure sensors S7R, S7B, S8R, S8B, S9R, and S9B, that it is difficult to move bucket 6 in the direction of arrow 1302 (including components in the -X axis direction and the -Z axis direction).

[0061] In this case, the controller 30 controls the movement of the boom 4 to move the bucket 6 to arrow 1303. Arrow 1303 includes a component in the +Z axis direction, which is opposite to arrow 1302 (which was difficult to move). Therefore, the movement of the boom 4 becomes relatively easy.

[0062] Similarly, Figure 4 illustrates a situation where the excavation operation by attachment AT has stopped due to hard soil. In the example shown in Figure 4, the angle of arm 5 with respect to the horizontal plane 1410 is greater than 290 degrees. In this case, a load is generated on bucket 6 in the direction of arrow 1401. The controller 30 then determines, based on the cylinder pressure detected by cylinder pressure sensors S7R, S7B, S8R, S8B, S9R, and S9B, that it is difficult to move bucket 6 in the direction of arrow 1402 (including the -X axis component and the +Z axis component).

[0063] In this situation, let's consider the case where the controller 30 moves the bucket 6 to arrow 1403 by raising the boom 4. Arrow 1403, like arrow 1402, includes a component in the +Z axis direction. Therefore, raising the boom 4 may be difficult in some cases.

[0064] In other words, when the excavation operation by the attachment AT stops, the uniform motion control by the controller 30 results in situations where it is easy to move the attachment AT and situations where it is difficult to move the attachment AT, depending on the posture of the attachment AT.

[0065] Therefore, in this embodiment, the controller 30 switches the control of the operation of the attachment AT depending on the posture of the attachment AT if the operation of the attachment AT stops while the attachment AT is performing excavation.

[0066] In this embodiment, the posture of the attachment AT is determined by whether the angle of the arm 5 is 290 degrees relative to the horizontal plane. In other words, the controller 30 switches the control of the operation of the attachment AT based on whether the arm angle is greater than 290 degrees relative to the horizontal plane. 290 degrees is just one example of a determination criterion, and is determined by adding 20 degrees to 270 degrees, which is the vertical direction relative to the horizontal plane. This embodiment does not limit the determination criterion for switching the operation to 290 degrees. The determination criterion can be any angle at which a vertical load is generated on the bucket 6 when the boom 4 is raised. Specifically, the determination criterion can be any angle of 270 degrees or more, for example, 315 degrees (270 degrees + 45 degrees).

[0067] <Block configuration of the excavator controller> Returning to Figure 2, the functional elements of the controller 30 and auxiliary storage device ST of the shovel 100 according to this embodiment will be described. In this embodiment, the controller 30 has an acquisition unit 301, a calculation unit 302, an autonomous control unit 303, and a determination unit 304 as functional elements. The controller 30 (an example of a control unit) according to this embodiment is configured to control the entire shovel 100.

[0068] The acquisition unit 301 acquires signals from various detection devices installed on the shovel 100. For example, the acquisition unit 301 acquires position information from the positioning device PS, which shows the measurement results such as the position and orientation of the shovel 100. The acquisition unit 301 also acquires image information from the imaging device S6.

[0069] Furthermore, the acquisition unit 301 acquires cylinder pressure from cylinder pressure sensors S7R, S7B, S8R, S8B, S9R, and S9B.

[0070] Furthermore, the acquisition unit 301 acquires the rotation angle of the boom 4 from the boom angle sensor S1, the rotation angle of the arm 5 from the arm angle sensor S2, and the rotation angle of the bucket 6 from the bucket angle sensor S3.

[0071] The calculation unit 302 calculates the orientation of the attachment AT. For example, the calculation unit 302 calculates the angle of the arm 5 relative to a horizontal plane (an example of a predetermined standard) from position information showing measurement results such as the position and orientation of the shovel 100, the rotation angle of the boom 4, and the rotation angle of the arm 5. In this embodiment, an example of calculating the angle of the arm 5 relative to a horizontal plane (an example of a predetermined standard) is described, but the orientation of the attachment AT is not limited to the angle of the arm 5 relative to a horizontal plane (an example of a predetermined standard). For example, the angle of the opening surface of the bucket 6 relative to a horizontal plane (an example of a predetermined standard) may also be calculated.

[0072] This embodiment describes an example in which a horizontal plane (an example of a predetermined standard) is applied as a standard for determining the posture of the attachment AT. However, this embodiment does not limit the predetermined standard to a horizontal plane. For example, it may be varied depending on the slope of the work site or the posture of the shovel 100. The predetermined standard may be, for example, a predetermined part of the shovel 100 (e.g., the center of gravity), or a plane that is substantially parallel to the ground.

[0073] Furthermore, the calculation unit 302 calculates the position of the tip of the bucket 6 from the rotation angle of the boom 4, the rotation angle of the arm 5, and the rotation angle of the bucket 6.

[0074] The autonomous control unit 303 generates a target trajectory for the tip of the bucket 6 according to the design surface information stored in the auxiliary storage device ST. Then, based on the position of the tip of the bucket 6 calculated by the calculation unit 302, the autonomous control unit 303 autonomously extends and retracts at least one of the boom cylinder 7, arm cylinder 8, and bucket cylinder 9 so that the tip of the bucket 6 moves along the target trajectory, thereby realizing the autonomous operation function of the shovel 100.

[0075] The target trajectory is intended to remove soil and debris above the design surface in order to form the design surface. The autonomous control unit 303 may derive the target trajectory based on the design surface and information about the terrain around the shovel 100 recognized by the imaging device S6.

[0076] The determination unit 304 determines whether or not the digging operation of the attachment AT has stopped, based on the rotation angles detected by the angle sensors S1, S2, and S3, while the attachment AT is performing digging operations using the autonomous operation function of the autonomous control unit 303.

[0077] When the determination unit 304 determines that the excavation operation of the attachment AT has stopped, it determines whether the angle of the arm 5 with respect to the horizontal plane, calculated by the calculation unit 302, is less than 290 degrees (an example of a predetermined angle).

[0078] The determination unit 304 then controls the boom 4 to rise if it determines that the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is less than 290 degrees (an example of a predetermined angle), and controls the bucket 6 to close if it determines that the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is the same as 290 degrees (an example of a predetermined angle) or that the angle of the arm 5 is greater than 290 degrees.

[0079] Figure 5 is an explanatory diagram showing an example of control of the operation of the attachment AT by the controller 30 according to this embodiment when the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees. In the example shown in Figure 5, if the excavation operation of the attachment AT does not stop, the tip of the bucket 6 is controlled to follow the target trajectory 1510.

[0080] Figure 5 shows an example where the excavation operation of the attachment AT stops due to hard soil or other debris when the tip of the bucket 6 reaches position 1501. The determination unit 304 determines that when the excavation operation of the attachment AT stops, the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is less than 290 degrees (an example of a predetermined angle).

[0081] Then, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is less than 290 degrees (an example of a predetermined angle), the autonomous control unit 303 controls the boom 4 to rise. As a result, the tip of the bucket 6 moves in direction 1502. In this embodiment, the autonomous control unit 303 raises the rotation angle of the boom 4 by 0.5 degrees and then performs an excavation operation (for example, closing the arm 5). Then, the determination unit 304 determines whether the tip of the bucket 6 has moved due to the excavation operation based on the rotation angle detected by the angle sensors S1, S2, and S3. If it is determined that the tip of the bucket 6 has moved, the autonomous control unit 303 resumes the excavation operation. If it is determined that the tip of the bucket 6 has not moved, the autonomous control unit 303 again controls the rotation angle of the boom 4 to rise by 0.5 degrees. By repeating this control, the excavation operation is resumed from the position where it was determined that the tip of the bucket 6 had moved. At that time, the autonomous control unit 303 regenerates the target trajectory.

[0082] In the example shown in Figure 5, the tip of the bucket 6 moves upward and then along the regenerated target trajectory 1511 after the above-described process by the autonomous control unit 303, so that excavation can be performed. The target trajectory 1511 is the trajectory generated by the autonomous control unit 303 to continue excavation.

[0083] In the example shown in Figure 5, after the digging operation of attachment AT stops, the autonomous control unit 303 raises the boom 4, and then restarts the digging operation with the load reduced. Therefore, the digging operation can be continued, thereby improving work efficiency.

[0084] Figure 6 is an explanatory diagram showing an example of control of the operation of the attachment AT by the controller 30 according to this embodiment when the angle of the arm 5 with respect to the horizontal plane is greater than 290 degrees. In the example shown in Figure 6, if the excavation operation of the attachment AT does not stop, the tip of the bucket 6 is controlled to follow the target trajectory 1610.

[0085] Figure 6 shows an example where the excavation operation of the attachment AT stops due to hard soil or other debris when the tip of the bucket 6 reaches position 1601. The determination unit 304 determines that when the excavation operation of the attachment AT stops, the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is greater than 290 degrees (an example of a predetermined angle).

[0086] Then, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is greater than 290 degrees (an example of a predetermined angle), the autonomous control unit 303 controls the closing of the bucket 6. Generally, the force generated by the closing of the bucket 6 is greater than the force generated by the digging operation of the boom 4 and arm 5. For this reason, even if the digging operation of the attachment AT stops, the autonomous control unit 303 can move the tip of the bucket 6 in direction 1611 by performing the closing operation of the bucket 6.

[0087] Then, when the opening surface of the bucket 6 is approximately aligned with the horizontal plane 1612, the autonomous control unit 303 stops the closing operation of the bucket 6 and terminates the excavation operation.

[0088] In other words, if the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is greater than 290 degrees (an example of a predetermined angle), when the excavation operation of the attachment AT stops, the lifting operation of the boom 4 may not allow the attachment AT to move upward due to the load of the soil and sand. Therefore, in this embodiment, by closing the bucket 6, it becomes possible to move the claws of the bucket 6 in direction 1611. Thus, the excavation operation can be completed with the bucket 6 loaded, thereby improving work efficiency.

[0089] Furthermore, if the determination unit 304 determines that the bucket 6 will not move due to the closing operation of the bucket 6 by the autonomous control unit 303, the autonomous control unit 303 performs a combination of control to open the arm 5 and control to close the bucket 6. In other words, if it is determined that the bucket 6 will not move, the arm 5 is gradually opened, causing the bucket 6 to move away from the hard soil, thus enabling the closing operation of the bucket 6. Then, when the opening surface of the bucket 6 is approximately aligned with the horizontal plane 1612, the closing operation of the bucket 6 is stopped, and the excavation operation is terminated. Therefore, even if the tip of the bucket 6 does not move due to hard soil, the bucket 6 can be closed and the excavation operation can be terminated, thereby improving work efficiency.

[0090] The processing procedure for autonomously controlled excavation operations by the controller 30 according to this embodiment will be described. Figure 7 is a flowchart showing the processing procedure for autonomously controlled excavation operations by the controller 30 according to this embodiment.

[0091] First, the autonomous control unit 303 generates a target trajectory and starts the excavation operation so that the tip of the bucket 6 follows the target trajectory (S1701).

[0092] Then, the determination unit 304 determines whether the digging operation of the attachment AT has stopped based on the rotation angles detected by the angle sensors S1, S2, and S3 while the attachment AT is performing the digging operation (S1702). If the determination unit 304 determines that the digging operation of the attachment AT has not stopped (S1702: NO), it proceeds to process S1705.

[0093] On the other hand, if the determination unit 304 determines that the excavation operation of the attachment AT has stopped (S1702: YES), it determines whether the angle of the arm 5 with respect to the horizontal plane, calculated by the calculation unit 302, is less than 290 degrees (S1703).

[0094] If the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees (S1703: YES), the autonomous control unit 303 raises the boom 4 and then resumes the digging operation so that the tip of the bucket 6 follows the regenerated target trajectory (S1704).

[0095] Subsequently, the determination unit 304 determines whether the excavation operation has ended by reaching the end point of the target trajectory (S1705). If it determines that the excavation operation has not ended (S1705: NO), the process proceeds to S1702. If it determines that the excavation operation has ended (S1705: YES), the process ends.

[0096] Furthermore, in S1703, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is not less than 290 degrees (in other words, 290 degrees or more) (S1703: NO), the autonomous control unit 303 closes the bucket 6 until the opening surface of the bucket 6 is approximately parallel to the horizontal plane (S1706), and then terminates the process.

[0097] This embodiment describes an example in which the control of the operation is switched according to the posture of the attachment AT while the shovel 100 is being autonomously controlled. However, this embodiment does not restrict the switching of the control of the operation to only when the shovel 100 is being autonomously controlled. For example, the above-described switching of the control of the operation may also be applied when the controller 30 is performing semi-automatic control to assist the operator.

[0098] In this embodiment, the controller 30 controls the bucket 6 to close when the angle of the arm 5 with respect to the horizontal plane is 290 degrees or more, thereby reducing the likelihood of the attachment AT becoming immobile due to the load, and thus improving work efficiency.

[0099] (Second embodiment) In the above-described embodiment, an example was given in which the bucket 6 is closed when the angle of the arm 5 with respect to the horizontal plane is 290 degrees or more when the excavation operation stops. However, the above-described embodiment is not limited to a method in which the bucket 6 is closed when the angle of the arm 5 with respect to the horizontal plane is 290 degrees. Therefore, in the second embodiment, an example will be described in which a different control is performed when the angle of the arm 5 with respect to the horizontal plane is 290 degrees or more when the excavation operation stops, compared to the above-described embodiment.

[0100] In this embodiment, when the determination unit 304 determines that the excavation operation of the attachment AT has stopped, it determines whether the angle of the arm 5 with respect to the horizontal plane, calculated by the calculation unit 302 based on the rotation angles detected by the angle sensors S1, S2, and S3, is less than 290 degrees. If it is determined that the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees, the autonomous control unit 303 performs the same control as in the first embodiment, and therefore the explanation is omitted.

[0101] Then, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is 290 degrees or more, the autonomous control unit 303 controls the raising of the boom 4. In other words, the autonomous control unit 303 performs the same control as when it determines that the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees. Then, if the boom 4 does not move upward when the determination unit 304 controls the raising of the boom 4, or if the load generated by the upward movement of the boom 4 is greater than a predetermined value, the autonomous control unit 303 stops the control to raise the boom 4 and controls the closing of the bucket 6. The load generated by the upward movement of the boom 4 is calculated from the cylinder pressure detected by the cylinder pressure sensors S7R, S7B, S8R, S8B, S9R, and S9B. The predetermined value is a threshold value determined according to the embodiment.

[0102] The processing procedure for autonomously controlled excavation operations by the controller 30 according to this embodiment will be described. Figure 8 is a flowchart showing the processing procedure for autonomously controlled excavation operations by the controller 30 according to this embodiment.

[0103] First, the autonomous control unit 303 generates a target trajectory and starts the excavation operation so that the tip of the bucket 6 follows the target trajectory (S1801).

[0104] Then, the determination unit 304 determines whether the digging operation of the attachment AT has stopped based on the rotation angles detected by the angle sensors S1, S2, and S3 while the attachment AT is performing the digging operation (S1802). If the determination unit 304 determines that the digging operation of the attachment AT has not stopped (S1802: NO), it proceeds to process S1805.

[0105] On the other hand, if the determination unit 304 determines that the excavation operation of the attachment AT has stopped (S1802: YES), it determines whether the angle of the arm 5 with respect to the horizontal plane, calculated by the calculation unit 302, is less than 290 degrees (S1803).

[0106] If the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees (S1803: YES), the autonomous control unit 303 raises the boom 4 and then resumes the digging operation so that the tip of the bucket 6 follows the newly generated target trajectory (S1804).

[0107] Subsequently, the determination unit 304 determines whether the target trajectory has reached its endpoint and the excavation operation has ended (S1805). If it determines that the excavation operation has not ended (S1805: NO), the process proceeds to S1802. If it determines that the excavation operation has ended (S1805: YES), the process ends.

[0108] Furthermore, in S1803, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is not less than 290 degrees (in other words, greater than or equal to 290 degrees) (S1803: NO), the autonomous control unit 303 starts the raising operation of the boom 4 (S1806).

[0109] The determination unit 304 determines whether or not the boom 4 moves upward based on the rotation angle detected by the boom angle sensor S1 when controlling the raising of the boom 4 (S1807). If it is determined that the boom 4 will move upward (S1807: YES), the autonomous control unit 303 raises the boom 4 and then resumes the digging operation so that the tip of the bucket 6 follows the regenerated target trajectory (S1808).

[0110] Subsequently, the determination unit 304 determines whether the target trajectory has reached its endpoint and the excavation operation has ended (S1805). If it determines that the excavation operation has not ended (S1805: NO), the process proceeds to S1802. If it determines that the excavation operation has ended (S1805: YES), the process ends.

[0111] On the other hand, in the process of S1807, if the determination unit 304 determines that the boom 4 does not move upward (S1807: NO), the autonomous control unit 303 performs a closing operation of the bucket 6 until the opening surface of the bucket 6 is approximately parallel to the horizontal plane (S1809), and then terminates the process.

[0112] In the processing procedure shown in Figure 8, an example was described in which, in S1807, the determination unit 304 determines whether or not the boom 4 moves upward when controlling the boom 4 to be raised. However, the determination in S1807 is not limited to determining whether or not the boom 4 moves upward. For example, the determination unit 304 may determine whether or not the load generated by the upward movement of the boom 4 is greater than a predetermined value when controlling the boom 4 to be raised.

[0113] In this embodiment, the controller 30 performs the above-described control so that when the angle of the arm 5 with respect to the horizontal plane is 290 degrees or more, and the boom 4 is able to move upward, it raises the boom 4 and allows the excavation operation to resume. If the boom 4 does not move upward, or if the load generated by the upward movement of the boom is greater than a predetermined value, the controller 30 stops the control to raise the boom 4 and controls the bucket 6 to close, thereby reducing the likelihood of the attachment AT becoming immobile due to the load and allowing the excavation operation to continue as much as possible, thereby improving work efficiency.

[0114] (Third embodiment) In the above-described embodiment, an example was explained in which the operation is switched depending on whether the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees when the excavation operation stops. However, the above-described embodiment does not limit the decision criterion for switching the operation to 290 degrees. Therefore, in this embodiment, an example in which two decision criteria for switching the operation are provided will be described. In other words, in this embodiment, by providing multiple decision criteria, the controller 30 performs control that corresponds to the attitude of the attachment in more detail.

[0115] In this embodiment, we describe an example in which 290 degrees and 315 degrees are used as criteria for determining the angle of arm 5 with respect to the horizontal plane. However, this embodiment does not limit the angles used as criteria to 290 degrees and 315 degrees, but rather can be appropriately set from angles of 270 degrees or more, depending on the embodiment. Furthermore, the criteria are not limited to two angles, but may be three or more angles.

[0116] In this embodiment, when the determination unit 304 determines that the excavation operation of the attachment AT has stopped, it determines whether the angle of the arm 5 with respect to the horizontal plane, calculated by the calculation unit 302 based on the rotation angles detected by the angle sensors S1, S2, and S3, is 315 degrees or greater.

[0117] Then, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is 315 degrees (an example of a second predetermined angle) or more, the autonomous control unit 303 controls the closing of the bucket 6.

[0118] Then, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is less than 315 degrees and greater than or equal to 290 degrees (an example of the first predetermined angle), the autonomous control unit 303 controls the raising of the boom 4. In other words, the autonomous control unit 303 performs the same control as in the first embodiment when it is determined that the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees. Then, if the determination unit 304 determines that the boom 4 does not move upward during the control to raise the boom 4, or if the load generated by the upward movement of the boom 4 is greater than a predetermined value, the autonomous control unit 303 stops the control to raise the boom 4 and controls the closing of the bucket 6.

[0119] Then, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane (an example of a predetermined standard) is less than 290 degrees (an example of a first predetermined angle), it performs the same control as in the first embodiment.

[0120] The processing procedure for autonomously controlled excavation operations by the controller 30 according to this embodiment will be described. Figure 9 is a flowchart showing the processing procedure for autonomously controlled excavation operations by the controller 30 according to this embodiment.

[0121] First, the autonomous control unit 303 generates a target trajectory and starts the excavation operation so that the tip of the bucket 6 follows the target trajectory (S1901).

[0122] Then, the determination unit 304 determines whether or not the digging operation of the attachment AT has stopped, based on the rotation angles detected by the angle sensors S1, S2, and S3 while the attachment AT is performing the digging operation (S1902). If the determination unit 304 determines that the digging operation of the attachment AT has not stopped (S1902: NO), it proceeds to process S1907.

[0123] On the other hand, if the determination unit 304 determines that the excavation operation of the attachment AT has stopped (S1902: YES), it determines whether the angle of the arm 5 with respect to the horizontal plane is 315 degrees or more (S1903).

[0124] If the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is 315 degrees or more (S1903: YES), the autonomous control unit 303 performs a closing operation of the bucket 6 until the opening surface of the bucket 6 is approximately parallel to the horizontal plane (S1904), and then terminates the process.

[0125] On the other hand, if the determination unit 304 determines that the angle of arm 5 with respect to the horizontal plane is less than 315 (S1903: NO), it determines whether the angle of arm 5 with respect to the horizontal plane is 290 degrees or more (S1905).

[0126] If the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees (S1905: NO), the autonomous control unit 303 raises the boom 4 and then resumes the digging operation so that the tip of the bucket 6 follows the newly generated target trajectory (S1906).

[0127] Subsequently, the determination unit 304 determines whether the excavation operation has ended by reaching the end point of the target trajectory (S1907). If it determines that the excavation operation has not ended (S1907: NO), the process proceeds to S1902. On the other hand, if the determination unit 304 determines that the excavation operation has ended (S1907: YES), the process ends.

[0128] Furthermore, in S1905, if the determination unit 304 determines that the angle of the arm 5 with respect to the horizontal plane is 290 degrees or more (S1905: YES), the autonomous control unit 303 starts the raising operation of the boom 4 (S1908).

[0129] The determination unit 304 determines whether or not the boom 4 moves upward based on the rotation angle detected by the boom angle sensor S1 when controlling the raising of the boom 4 (S1909). If it is determined that the boom 4 will move upward (S1909: YES), the autonomous control unit 303 raises the boom 4 and then resumes the digging operation so that the tip of the bucket 6 follows the regenerated target trajectory (S1910).

[0130] Subsequently, the determination unit 304 determines whether the excavation operation has ended by reaching the end point of the target trajectory (S1907). If it determines that the excavation operation has not ended (S1907: NO), the process proceeds to S1902. On the other hand, if the determination unit 304 determines that the excavation operation has ended (S1907: YES), the process ends.

[0131] On the other hand, in the process of S1909, if the determination unit 304 determines that the boom 4 does not move upward (S1909: NO), the autonomous control unit 303 performs a closing operation of the bucket 6 until the opening surface of the bucket 6 is approximately parallel to the horizontal plane (S1904), and then terminates the process.

[0132] In this embodiment, by using 290 degrees and 315 degrees as criteria for determining the angle of the arm 5 with respect to the horizontal plane, it is possible to switch the excavation operation by the attachment AT according to the posture of the attachment AT and the condition of the material to be excavated (e.g., soil), thereby improving work efficiency.

[0133] <effect> In the embodiment described above, if the attachment AT stops operating while the attachment AT is performing excavation, the controller 30 switches the control of the attachment AT's operation depending on the position of the attachment AT. This reduces the load on the attachment AT, thereby facilitating its operation. Consequently, the controller 30 can improve the work efficiency of the shovel 100.

[0134] The embodiments described above illustrate an example of operation control by the controller 30. For example, the controller 30 may control the operation to terminate the excavation by raising the boom 4 when the angle of the arm 5 with respect to the horizontal plane is less than 290 degrees. Alternatively, the controller 30 may control the operation to raise the boom 4 after opening the arm 5 when the angle of the arm 5 with respect to the horizontal plane is 290 degrees or more. In other words, in the technology of this disclosure, it is sufficient for the controller 30 to switch operations according to the posture of the attachment AT, and there is no limitation on what kind of operation it may perform.

[0135] 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]

[0136] 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 ST auxiliary storage 30 controllers 301 Acquisition Department 302 Calculation Unit 303 Autonomous Control Unit 304 Judgment section

Claims

1. Attachments and, A control device that switches the control of the attachment's operation depending on the position of the attachment if the attachment stops operating while excavating, A shovel equipped with a shovel.

2. The attachment includes a boom, an arm attached to the tip of the boom, and a bucket attached to the tip of the arm. The control device controls the boom to be raised when the angle of the arm relative to a predetermined reference is less than a predetermined angle while the attachment is performing an excavation operation, and controls the bucket to be closed when the angle of the arm relative to the predetermined reference is greater than the predetermined angle. The shovel according to claim 1.

3. The attachment includes a boom, an arm attached to the tip of the boom, and a bucket attached to the tip of the arm. The control device, while the attachment is performing an excavation operation, controls the boom to be raised if the angle of the arm relative to a predetermined reference at the time the excavation operation of the attachment stops is greater than a predetermined angle, and if the boom does not move upward as a result of the boom raising control, or if the load generated by the upward movement of the boom is greater than a predetermined value, stops the boom raising control and controls the bucket to be closed. The shovel according to claim 1.

4. The attachment includes a boom, an arm attached to the tip of the boom, and a bucket attached to the tip of the arm. The control device controls the boom to be raised when the angle of the arm with respect to a predetermined reference is greater than a first predetermined angle and less than a second predetermined angle when the excavation operation of the attachment stops, and stops the boom to be raised and controls the bucket to be closed when the boom does not move upward as a result of the boom to be raised, or when the load generated by the upward movement of the boom is greater than a predetermined value. The control device performs control to close the bucket when the angle of the arm with respect to the predetermined reference is greater than the second predetermined angle when the excavation operation of the attachment stops. The shovel according to claim 1.

5. The attachment includes a boom, an arm attached to the tip of the boom, and a bucket attached to the tip of the arm. The control device, when the bucket does not move during the control to close the bucket, performs a combination of the control to open the arm and the control to close the bucket. The shovel according to claim 1.

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