JP2022154674A - Excavator - Google Patents

Abstract

To provide an excavator capable of evaluating the stability of the excavator regardless of the inclination of the excavator.SOLUTION: An excavator 100 in an embodiment of the disclosure includes: an undercarriage 1; an upper revolving body 3 that is mounted on the undercarriage 1 rotatably; an attachment AT that is attached to the upper revolving body 3, and includes a boom 4, an arm 5, and a bucket 6; and a controller 30 that estimates the volume of earth and sand lifted by the attachment AT using the bucket 6, and based on the estimated volume of earth and sand, evaluates the stability of the posture of the excavator including the undercarriage 1 and the upper revolving body 3.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to excavators.

For example, there is known a technique of detecting a forward (boom side) tilt of the aircraft using a tilt sensor (see Patent Document 1).

JP-A-63-11722

However, with the above-described technique, it is not possible to evaluate that the stability of the posture of the excavator is degraded until after the rear portion of the undercarriage 1 has lifted and the machine body has actually tilted.

Therefore, in view of the above problems, it is an object of the present invention to provide a technique capable of evaluating the stability of an excavator regardless of the inclination of the machine body.

To achieve the above objectives, in one embodiment of the present disclosure,
a lower running body;
an upper rotating body rotatably mounted on the lower traveling body;
a work attachment attached to the upper rotating structure and including a boom, an arm, and a bucket;
a control device for estimating the volume of earth and sand to be lifted by the work attachment using the bucket, and evaluating the stability of the attitude of the machine body including the lower traveling body and the upper rotating body based on the estimated volume of earth and sand; prepare
A shovel is provided.

According to the above-described embodiment, the stability of the excavator can be evaluated regardless of the inclination of the machine body.

It is an outline view showing an example of a shovel. It is a block diagram which shows an example of a structure of a shovel. It is a figure explaining an example of the evaluation method of the stability of the attitude|position of a shovel. FIG. 7 is a diagram illustrating another example of a method for evaluating the stability of the posture of the shovel; FIG. 11 is a block diagram showing another example of the configuration of the shovel;

Embodiments will be described below with reference to the drawings.

[Overview of Excavator]
First, with reference to FIG. 1, the outline of the excavator according to the present embodiment will be described.

FIG. 1 is an external view showing an example of a shovel 100 according to this embodiment.

As shown in FIG. 1, the excavator 100 according to the present embodiment includes a lower traveling body 1 and an upper revolving body 3 mounted on the lower traveling body 1 so as to be rotatable via a revolving mechanism 2 for performing various operations. attachment AT and a cabin 10. Below, in front of the excavator 100 (upper revolving body 3), when the excavator 100 is viewed along the revolving shaft of the upper revolving body 3 from directly above in plan view (top view), the attachment to the upper revolving body 3 extends. Corresponds to the output direction. The left and right sides of the excavator 100 (upper revolving body 3) correspond to the left and right sides of the operator seated in the operator's seat in the cabin 10, respectively.

The undercarriage 1 includes, for example, a pair of left and right crawlers 1C. The lower traveling body 1 causes the excavator 100 to travel by hydraulically driving the respective crawlers 1C by the left traveling hydraulic motor 1ML and the right traveling hydraulic motor 1MR (see FIGS. 2 and 3).

The upper revolving structure 3 revolves with respect to the lower traveling structure 1 by hydraulically driving the revolving mechanism 2 with a revolving hydraulic motor 2A.

Attachment AT (an example of a work attachment) includes boom 4 , arm 5 and bucket 6 .

The boom 4 is attached to the center of the front part of the upper rotating body 3 so as to be able to be raised. An arm 5 is attached to the tip of the boom 4 so as to be vertically rotatable. possible to be installed.

Bucket 6 is an example of an end attachment. The bucket 6 is used, for example, for excavation work or the like. Further, another end attachment may be attached to the tip of the arm 5 instead of the bucket 6, depending on the type of work and the like. Other end attachments may be other types of buckets such as, for example, large buckets, slope buckets, dredging buckets, and the like. Other end attachments may also be types of end attachments other than buckets, such as agitators, breakers, grapples, and the like.

The boom 4, arm 5, and bucket 6 are hydraulically driven by boom cylinders 7, arm cylinders 8, and bucket cylinders 9 as hydraulic actuators, respectively.

The excavator 100 may be configured such that some of the driven elements such as the lower traveling body 1, the upper revolving body 3, the boom 4, the arm 5, and the bucket 6 are electrically driven. That is, the excavator 100 may be a hybrid excavator, an electric excavator, or the like in which some of the driven elements are driven by electric actuators.

The cabin 10 is a cockpit in which an operator boards, and is mounted on the front left side of the upper revolving structure 3 .

As will be described later, the cabin 10 may be omitted when the excavator 100 is remotely controlled or fully automated.

Also, the excavator 100 may be equipped with, for example, a communication device 60 and be capable of communicating with an external device through a predetermined communication line.

The communication line includes, for example, a wide area network (WAN). A wide area network may include, for example, a mobile communication network terminating at a base station. The wide area network may also include, for example, a satellite communication network that uses communication satellites over the excavator 100 . The wide area network may also include, for example, the Internet network. Also, the communication line may include, for example, a local network (LAN: Local Area Network) such as a facility where the management device 200 is installed. The local network may be a wireless line, a wired line, or a line containing both. Also, the communication line NW may include, for example, a short-range communication line based on a predetermined wireless communication method such as WiFi or Bluetooth (registered trademark).

The external device is, for example, a management device that manages (monitors) the operating state, operating state, and the like of the excavator 100 . As a result, the excavator 100 can transmit (upload) various information to the management device and receive various signals (for example, information signals and control signals) from the management device.

The management device is, for example, a cloud server or an on-premises server installed at a remote location different from the work site of the excavator 100 . In addition, the management device is installed, for example, inside the work site of the excavator 100 (for example, a management office at the work site) or in a place relatively close to the work site (for example, a communication facility such as a nearby base station). edge server. Also, the management device may be a terminal device for management used at the work site.

Also, the external device may be, for example, a terminal device (user terminal) used by the user of the excavator 100 . The user of the excavator 100 includes, for example, an operator, a serviceman, a manager, an owner, etc. of the excavator 100 . Thereby, the excavator 100 can transmit various kinds of information to the user terminal, and can provide the information on the excavator 100 to the user of the excavator 100 .

The excavator 100 operates actuators (for example, hydraulic actuators) in response to operations by an operator on board the cabin 10, and operates elements such as the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, and the bucket 6. (hereinafter referred to as “driven element”).

Further, instead of being configured to be operable by the operator of the cabin 10 , or in addition, the excavator 100 may be configured to be remotely controlled (remotely controlled) from the outside of the excavator 100 . When the excavator 100 is remotely controlled, the interior of the cabin 10 may be unmanned. The following description is based on the premise that the operator's operation includes at least one of an operation of the operating device 26 by the operator of the cabin 10 and a remote operation by an external operator.

The remote operation includes, for example, a mode in which the excavator 100 is operated by a user (operator)'s input regarding the actuator of the excavator 100 performed by a predetermined external device (for example, the management device described above). In this case, the excavator 100 transmits, for example, image information (hereinafter referred to as "surrounding image") around the excavator 100 based on the output of the imaging device S6, which will be described later, to the external device, and the image information is displayed on a display provided on the external device. It may be displayed on a device (hereinafter "remote display device"). Various information images (information screens) displayed on the output device 50 in the cabin 10 of the excavator 100 may also be displayed on the remote control display device of the external device. As a result, the operator of the external device remotely operates the excavator 100 while confirming the display contents such as the surrounding image representing the surroundings of the excavator 100 and various information images displayed on the remote control display device. be able to. Then, the excavator 100 operates the actuators according to a remote control signal representing the details of remote control received from an external device, and operates the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, and the bucket 6. may drive a driven element such as

In addition, the remote operation may include, for example, a mode in which the excavator 100 is operated by a person (for example, a worker) around the excavator 100 externally inputting voice or gesture to the excavator 100 . Specifically, the excavator 100 uses a voice input device (for example, a microphone), an imaging device, or the like mounted on the excavator 100 (the excavator 100), and the sounds uttered by the surrounding workers or the like, or the voices produced by the workers, etc. Recognize gestures, etc. The excavator 100 operates the actuators according to the contents of the recognized voice, gesture, etc., and drives the driven elements such as the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, and the bucket 6. you can

In addition, the excavator 100 may automatically operate the actuator regardless of the content of the operator's operation. As a result, the excavator 100 has a function of automatically operating at least a part of the driven elements such as the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, and the bucket 6, that is, the so-called "automatic driving function". Alternatively, it implements a "Machine Control (MC) function".

The automatic operation function includes a function of automatically operating a driven element (actuator) other than the driven element (actuator) to be operated in accordance with the operator's operation on the operation device 26 or remote control, that is, a so-called "semi-automatic operation". functions" or "operation-assisted MC functions" may be included. In addition, the automatic operation function includes a function that automatically operates at least a part of a plurality of driven elements (hydraulic actuators) on the premise that the operator does not operate the operation device 26 or remote control, that is, the so-called "fully automatic operation". functions” or “fully automated MC functions” may be included. In the excavator 100, when the fully automatic operation function is effective, the inside of the cabin 10 may be in an unmanned state. In addition, the semi-automatic operation function, the fully automatic operation function, and the like may include a mode in which the operation contents of the driven elements (actuators) to be automatically operated are automatically determined according to predetermined rules. In the semi-automatic operation function, the fully automatic operation function, etc., the excavator 100 autonomously makes various judgments, and according to the judgment results, the driven elements (hydraulic actuators) to be automatically operated autonomously operate. A mode in which the content is determined (a so-called “autonomous driving function”) may be included.

[Example of excavator configuration]
Next, an example of the configuration of the shovel 100 according to this embodiment will be described with reference to FIG. 2 .

FIG. 2 is a block diagram showing an example of the configuration of the excavator 100 according to this embodiment. In FIG. 2, the path through which mechanical power is transmitted is double lines, the path through which high-pressure hydraulic fluid that drives the hydraulic actuator flows is solid lines, the path through which pilot pressure is transmitted is dashed lines, and the path through which electrical signals are transmitted is Each is indicated by a dotted line. The same applies to FIG. 5, which will be described later.

The excavator 100 includes a hydraulic drive system for hydraulically driving the driven elements, an operation system for operating the driven elements, a user interface system for exchanging information with the user, a communication system for communication with the outside, a control system for various controls, and the like. including each component of

<Hydraulic drive system>
As shown in FIG. 2, the hydraulic drive system of the excavator 100 according to the present embodiment includes the lower traveling body 1 (left and right crawlers 1C), the upper revolving body 3, the boom 4, the arm 5, the bucket 6, and the like, as described above. a hydraulic actuator for hydraulically driving each of the driven elements of the . The hydraulic actuators include travel hydraulic motors 1ML and 1MR, swing hydraulic motor 2A, boom cylinder 7, arm cylinder 8, bucket cylinder 9, and the like. Also, the hydraulic drive system of the excavator 100 according to this embodiment includes an engine 11 , a regulator 13 , a main pump 14 and a control valve 17 .

The engine 11 is a prime mover and a main power source in the hydraulic drive system. The engine 11 is, for example, a diesel engine that uses light oil as fuel. The engine 11 is mounted, for example, on the rear portion of the upper revolving body 3 . The engine 11 rotates at a preset target speed under direct or indirect control by a controller 30 to be described later, and drives the main pump 14 and the pilot pump 15 .

Note that the excavator 100 may be equipped with another prime mover instead of or in addition to the engine 11 . Another prime mover is, for example, an electric motor capable of driving the main pump 14 and the pilot pump 15 .

The regulator 13 controls (adjusts) the discharge amount of the main pump 14 under the control of the controller 30 . For example, the regulator 13 adjusts the angle of the swash plate of the main pump 14 (hereinafter referred to as “tilt angle”) according to a control command from the controller 30 .

The main pump 14 supplies hydraulic fluid to the control valve 17 through a high pressure hydraulic line. The main pump 14 is mounted, for example, on the rear portion of the upper rotating body 3, similar to the engine 11. As shown in FIG. The main pump 14 is driven by the engine 11 as described above. The main pump 14 is, for example, a variable displacement hydraulic pump, and as described above, under the control of the controller 30, the regulator 13 adjusts the tilting angle of the swash plate, thereby adjusting the stroke length of the piston and discharging. The flow rate (discharge pressure) is controlled.

The control valve 17 is a hydraulic control device that controls a hydraulic actuator according to the content of an operator's operation on the operation device 26 or remote operation, or an operation command relating to the automatic operation function output from the controller 30 . The control valve 17 is mounted, for example, in the central portion of the upper revolving body 3 . The control valve 17 is connected to the main pump 14 via the high-pressure hydraulic line, as described above, and supplies the hydraulic oil supplied from the main pump 14 according to the operator's operation or the operation command output from the controller 30. , selectively feeding the respective hydraulic actuators. Specifically, the control valve 17 includes a plurality of control valves (also referred to as "direction switching valves") 17A to 17F that control the flow rate and flow direction of hydraulic oil supplied from the main pump 14 to each hydraulic actuator. .

The control valve 17A is configured to supply hydraulic fluid to the traveling hydraulic motor 1ML, to discharge the hydraulic fluid from the traveling hydraulic motor 1ML, and to return the hydraulic fluid to the tank. As a result, the control valve 17B can drive the traveling hydraulic motor 1ML with the pilot pressure supplied from the operating device 26 or the hydraulic control valve 31. FIG.

The control valve 17B is configured to be able to supply working oil to the travel hydraulic motor 1MR, discharge the working oil from the travel hydraulic motor 1MR, and return it to the tank. Thereby, the control valve 17B can drive the traveling hydraulic motor 1MR with the pilot pressure supplied from the operating device 26 or the hydraulic control valve 31. FIG.

The control valve 17C is configured to be able to supply hydraulic fluid to the hydraulic swing motor 2A, discharge the hydraulic fluid from the hydraulic hydraulic motor 2A, and return it to the tank. Thereby, the control valve 17C can drive the swing hydraulic motor 2A by the pilot pressure supplied from the operation device 26 or the hydraulic control valve 31. As shown in FIG.

The control valve 17D is configured to be able to supply hydraulic fluid to the boom cylinder 7, discharge the hydraulic fluid from the boom cylinder 7, and return it to the tank. Thereby, the control valve 17</b>D can drive the boom cylinder 7 according to the pilot pressure supplied from the operating device 26 or the hydraulic control valve 31 .

The control valve 17E is configured to supply hydraulic fluid to the arm cylinder 8, discharge the hydraulic fluid from the arm cylinder 8, and return it to the tank. Thereby, the control valve 17E can drive the arm cylinder 8 by the pilot pressure supplied from the operating device 26 or the hydraulic control valve 31. As shown in FIG.

The control valve 17F is configured to supply the hydraulic oil to the bucket cylinder 9, to discharge the hydraulic oil from the bucket cylinder 9, and to return it to the tank. Thereby, the control valve 17</b>F can drive the bucket cylinder 9 according to the pilot pressure supplied from the operating device 26 or the hydraulic control valve 31 .

<Operation system>
As shown in FIG. 2 , the operating system of the excavator 100 according to this embodiment includes a pilot pump 15 , an operating device 26 , a hydraulic control valve 31 , a shuttle valve 32 and a hydraulic control valve 33 .

Pilot pump 15 supplies pilot pressure to various hydraulic devices via pilot line 25 . The pilot pump 15 is mounted, for example, on the rear portion of the upper revolving body 3 in the same manner as the engine 11 . The pilot pump 15 is, for example, a fixed displacement hydraulic pump, and is driven by the engine 11 as described above.

Incidentally, the pilot pump 15 may be omitted. In this case, relatively high-pressure hydraulic fluid discharged from the main pump 14 is decompressed by a predetermined pressure reducing valve, and then relatively low-pressure hydraulic fluid is supplied as pilot pressure to various hydraulic devices.

The operating device 26 is provided near the cockpit of the cabin 10, and is used by the operator to operate various driven elements (lower running body 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc.). . In other words, the operating device 26 includes hydraulic actuators (that is, traveling hydraulic motors 1ML and 1MR, turning hydraulic motor 2A, boom cylinder 7, arm cylinder 8, bucket cylinder 9, etc.) for the operator to drive respective driven elements. is used to perform operations on The operating device 26 includes, for example, lever devices that operate the boom 4 (boom cylinder 7), the arm 5 (arm cylinder 8), the bucket 6 (bucket cylinder 9), and the upper rotating body 3 (swing hydraulic motor 2A). include. Further, the operating device 26 includes, for example, a pedal device or a lever device for operating the left and right crawlers (traveling hydraulic motors 1ML and 1MR) of the lower traveling body 1, respectively.

For example, as shown in FIG. 2, the operating device 26 is hydraulically piloted. Specifically, the operating device 26 utilizes the hydraulic oil supplied from the pilot pump 15 through the pilot line 25 and the pilot line 25A branched therefrom, and applies the pilot pressure according to the operation content to the secondary side pilot line. 27A. The pilot line 27A is connected to one inlet port of the shuttle valve 32 and connected to the control valve 17 via the pilot line 27 connected to the outlet port of the shuttle valve 32 . As a result, a pilot pressure can be input to the control valve 17 through the shuttle valve 32 according to the operation details of various driven elements (hydraulic actuators) in the operating device 26 . Therefore, the control valve 17 can drive each hydraulic actuator according to the operation content of the operating device 26 such as an operator.

Note that the operating device 26 may be of an electric type. In this case, the operation device 26 outputs an electric signal (hereinafter referred to as “operation signal”) corresponding to the content of the operation, and the operation signal is received by the controller 30 . Then, the controller 30 outputs to the hydraulic control valve 31 a control command corresponding to the content of the operation signal, that is, a control signal corresponding to the content of the operation on the operating device 26 . As a result, the pilot pressure corresponding to the operation content of the operation device 26 is input from the hydraulic control valve 31 to the control valve 17, and the control valve 17 drives the respective hydraulic actuators according to the operation content of the operation device 26. can be done. Further, the control valves 17A to 17F (direction switching valves) incorporated in the control valve 17 and driving respective hydraulic actuators may be electromagnetic solenoid type. In this case, the operation signal output from the operating device 26 may be directly input to the control valve 17, that is, to each of the electromagnetic solenoid type control valves 17A to 17F.

The hydraulic control valve 31 is provided for each driven element (hydraulic actuator) to be operated by the operating device 26 . That is, the hydraulic control valve 31 includes, for example, a left crawler (traveling hydraulic motor 1ML), a right crawler (traveling hydraulic motor 1MR), an upper revolving body 3 (revolving hydraulic motor 2A), a boom 4 (boom cylinder 7), an arm 5 (arm cylinder 8) and bucket 6 (bucket cylinder 9). The hydraulic control valve 31 is provided, for example, in the pilot line 25B between the pilot pump 15 and the control valve 17, and is configured such that its passage area (that is, the cross-sectional area through which hydraulic oil can flow) can be changed. good. As a result, the hydraulic control valve 31 can output a predetermined pilot pressure to the secondary side pilot line 27B using the hydraulic fluid of the pilot pump 15 supplied through the pilot line 25B. Therefore, as shown in FIG. 2, the hydraulic control valve 31 indirectly controls a predetermined pilot pressure according to the control signal from the controller 30 through the shuttle valve 32 between the pilot lines 27B and 27B. 17.

The controller 30 may, for example, control the hydraulic control valve 31 to implement an automatic operation function. Specifically, the controller 30 outputs a control signal corresponding to an operation command related to the automatic operation function to the hydraulic control valve 31 regardless of whether or not the operation device 26 is operated. As a result, the controller 30 can cause the hydraulic control valve 31 to supply the control valve 17 with the pilot pressure corresponding to the operation command relating to the automatic operation function, thereby realizing the operation of the excavator 100 based on the automatic operation function.

Further, the controller 30 may control the hydraulic control valve 31 to realize remote control of the excavator 100, for example. Specifically, the controller 30 outputs a control signal to the hydraulic control valve 31 through the communication device 60, corresponding to the details of the remote operation designated by the remote operation signal received from the external device. As a result, the controller 30 causes the hydraulic control valve 31 to supply the pilot pressure corresponding to the content of the remote operation to the control valve 17, thereby realizing the operation of the excavator 100 based on the operator's remote operation.

As described above, when the electric operating device 26 is employed, the shuttle valve 32, which will be described later, is omitted. Therefore, the hydraulic control valve 31 can directly apply a predetermined pilot pressure to the control valve 17 through the pilot line 27</b>B and the pilot line 27 in accordance with the control signal from the controller 30 . Therefore, the controller 30 can cause the control valve 17 to supply the pilot pressure corresponding to the operation content of the electric operation device 26 from the hydraulic control valve 31, and can realize the operation of the excavator 100 based on the operator's operation.

The shuttle valve 32 has two inlet ports and one outlet port, and outputs to the outlet port the hydraulic fluid having the higher pilot pressure among the pilot pressures input to the two inlet ports. The shuttle valve 32 is provided for each driven element (hydraulic actuator) to be operated by the operating device 26 . That is, the shuttle valve 32 includes, for example, a left crawler (traveling hydraulic motor 1ML), a right crawler (traveling hydraulic motor 1MR), an upper revolving body 3 (revolving hydraulic motor 2A), a boom 4 (boom cylinder 7), and an arm 5. (arm cylinder 8) and bucket 6 (bucket cylinder 9). One of the two inlet ports of the shuttle valve 32 is connected to the pilot line 27A on the secondary side of the operating device 26 (specifically, the above-described lever device or pedal device included in the operating device 26), and the other is connected to the pilot line 27A. It is connected to the pilot line 27B on the secondary side of the hydraulic control valve 31 . The outlet port of shuttle valve 32 is connected through pilot line 27 to the corresponding control valve pilot port of control valve 17 . The corresponding control valve is a control valve that drives the hydraulic actuator that is the object of operation of the above-described lever device or pedal device that is connected to one inlet port of the shuttle valve 32 . Therefore, these shuttle valves 32 correspond to the higher one of the pilot pressure of the pilot line 27A on the secondary side of the operating device 26 and the pilot pressure of the pilot line 27B on the secondary side of the hydraulic control valve 31. It can act on the pilot port of the control valve. That is, the controller 30 causes the hydraulic control valve 31 to output a pilot pressure higher than the pilot pressure on the secondary side of the operation device 26, thereby controlling the corresponding control valve regardless of the operator's operation of the operation device 26. be able to. Therefore, the controller 30 can control the operation of the driven elements (the lower traveling body 1, the upper rotating body 3, and the attachment AT) regardless of the operation state of the operating device 26 by the operator, and realize the automatic driving function. can.

The hydraulic control valve 33 is provided in a pilot line 27A that connects the operating device 26 and the shuttle valve 32 . The hydraulic control valve 33 is configured, for example, so that its flow passage area can be changed. The hydraulic control valve 33 operates according to control signals input from the controller 30 . Thereby, the controller 30 can forcibly reduce the pilot pressure output from the operating device 26 when the operating device 26 is operated by the operator. Therefore, even when the operation device 26 is being operated, the controller 30 can forcibly suppress or stop the operation of the hydraulic actuator corresponding to the operation of the operation device 26 . Further, for example, even when the operating device 26 is being operated, the controller 30 reduces the pilot pressure output from the operating device 26 to be lower than the pilot pressure output from the hydraulic control valve 31. can be done. Therefore, the controller 30 controls the hydraulic control valve 31 and the hydraulic control valve 33 to apply a desired pilot pressure to the pilot port of the control valve in the control valve 17, regardless of the operation content of the operating device 26, for example. can work reliably. Therefore, by controlling the hydraulic control valve 33 in addition to the hydraulic control valve 31, the controller 30 can realize the automatic operation function and the remote control function of the excavator 100 more appropriately.

If the excavator 100 is not equipped with a remote control function and an automatic operation function, the pilot line 27B, the hydraulic control valve 31, and the shuttle valve 32 are omitted, and the pilot lines 27 and 27A are connected one-to-one. may be aggregated into the pilot line of

<User interface system>
As shown in FIG. 2 , the user interface system of the excavator 100 according to this embodiment includes an operation device 26 , an output device 50 and an input device 52 .

The output device 50 outputs various information to the user (operator) of the excavator 100 inside the cabin 10 . The output device 50 includes a display device 50A and a sound output device 50B.

The display device 50A is provided at a location within the cabin 10 that is easily visible to a seated operator, displays various information images, and outputs various information in a visual manner. The display device 50A is, for example, a liquid crystal display or an organic EL (Electroluminescence) display.

Note that the output device 50 may include a lighting device or the like capable of outputting various information in a visual manner. The lighting equipment is, for example, a warning light or the like.

The sound output device 50B outputs various information in an auditory manner. The sound output device 50B includes, for example, a buzzer, an alarm, a speaker, and the like.

Note that the output device 50 may include a device that outputs various types of information by a method other than the visual method or the auditory method, for example, a tactile method such as vibration of the cockpit.

The input device 52 is provided in the cabin 10 in a range close to the seated operator, receives various inputs from the operator, and receives signals corresponding to the received inputs into the controller 30 .

For example, the input device 52 is an operation input device that receives operation input. The operation input device includes a touch panel mounted on the display device 50A, a touch pad installed around the display device 50A, a button switch, a lever, a toggle, a knob switch provided on the operation device 26 (lever device), and the like. you can

Further, for example, the input device 52 may be a voice input device that receives voice input from the operator. Audio input devices include, for example, microphones.

Further, for example, the input device 52 may be a gesture input device that receives gesture input from the operator. The gesture input device includes, for example, an imaging device (indoor camera) installed inside the cabin 10 .

<Communication system>
As shown in FIG. 2 , the communication system of the excavator 100 according to this embodiment includes a communication device 60 .

The communication device 60 connects to a predetermined communication line and communicates with a device (for example, a management device) provided separately from the excavator 100 . Devices provided separately from the excavator 100 may include devices outside the excavator 100 as well as portable terminal devices brought into the cabin 10 by the user of the excavator 100 . The communication device 60 may include, for example, a mobile communication module conforming to standards such as ^4G (4th Generation) and ^5G (5th Generation). Communication device 60 may also include, for example, a satellite communication module. The communication device 60 may also include, for example, a WiFi communication module, a Bluetooth (registered trademark) communication module, and the like. The communication device 60 may also include a communication module or the like capable of wired communication with a terminal device or the like connected through a cable connected to a predetermined connector, for example.

<Control system>
As shown in FIG. 2 , the control system of the excavator 100 according to this embodiment includes a controller 30 and a storage device 47 . Further, the control system of the excavator 100 according to the present embodiment includes an operation pressure sensor 29, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a body attitude sensor S4, a turning angle sensor S5, and an imaging device S6.

A controller 30 (an example of a control device) performs various controls related to the excavator 100 . The functions of the controller 30 may be implemented by any hardware, or any combination of hardware and software. For example, the controller 30 is a computer including a CPU (Central Processing Unit), a memory device such as RAM (Random Access Memory), a non-volatile auxiliary storage device such as ROM (Read Only Memory), an interface device for various inputs and outputs, etc. is centered on The controller 30 implements various functions by, for example, loading a program installed in the auxiliary storage device into the memory device and executing it on the CPU.

The controller 30 controls the operation of the hydraulic actuator (driven element) of the excavator 100, for example, with the hydraulic control valve 31 as a control target.

Specifically, the controller 30 may control the operation of the hydraulic actuator (driven element) of the excavator 100 based on the operation of the operation device 26 with the hydraulic control valve 31 as the control target.

Further, the controller 30 may control the hydraulic actuator (driven element) of the excavator 100 by remote control with the hydraulic control valve 31 as a control target. That is, the operation of the hydraulic actuator (driven element) of the excavator 100 may include remote control of the hydraulic actuator from outside the excavator 100 .

Further, the controller 30 may control the automatic operation function of the excavator 100 with the hydraulic control valve 31 as a control target. That is, the operation of the hydraulic actuator of the excavator 100 may include an operation command of the hydraulic actuator of the excavator 100 that is output based on the automatic operation function.

The controller 30 also performs control for preventing the excavator 100 from overturning forward (hereinafter referred to as “overturn prevention control”). The controller 30 includes a posture measurement unit 301 , an earth and sand volume estimation unit 302 , a stability evaluation unit 303 , and an overturn prevention control unit 304 as functional units related to overturn prevention control. The functions of the posture measurement unit 301, the sediment volume estimation unit 302, the stability evaluation unit 303, and the overturn prevention control unit 304 are realized by, for example, loading a program installed in the auxiliary storage device into the memory device and executing it by the CPU. be done.

Note that part of the functions of the controller 30 may be implemented by another controller (control device). In other words, the functions of the controller 30 may be distributed and implemented by a plurality of controllers.

Various data are stored in the storage device 47 . The various data include data used in processing of the controller 30 . For example, the various data may be stored in advance when the excavator 100 is shipped from the factory, or may be registered (stored) in the storage device 47 via the communication device 60 afterward.

The storage device 47 stores, for example, survey data (an example of topographical information) of the work site of the excavator 100 . The survey data is, for example, three-dimensional data representing the topography of the work site of the excavator 100 before construction, which is generated based on the output of a drone or the like equipped with a camera, a distance sensor (eg, LIDAR), or the like. The survey data is generated, for example, by the management device and received from the management device through the communication device 60 (an example of the first acquisition device).

Some or all of the functions of the storage device 47 may be realized by an internal memory (for example, an auxiliary storage device) of the controller 30 .

The operation pressure sensor 29 detects the pilot pressure on the secondary side (pilot line 27A) of the hydraulic pilot type operation device 26, that is, the pilot pressure corresponding to the operation state of each driven element (hydraulic actuator) in the operation device 26. To detect. A pilot pressure detection signal corresponding to the operation state of the lower traveling body 1, the upper swing body 3, the boom 4, the arm 5, the bucket 6, etc. in the operating device 26 by the operation pressure sensor 29 is taken into the controller 30.

Note that the operating pressure sensor 29 is omitted when the electric operating device 26 is employed. In this case, the controller 30 can grasp the operating state of each driven element (hydraulic actuator) based on the operating signal received from the electric operating device 26 .

The boom angle sensor S1 (an example of a second acquisition device) detects the attitude angle of the boom 4 (hereinafter referred to as the "boom angle") with respect to a predetermined reference (for example, a horizontal plane or one of the two ends of the movable angle range of the boom 4). ) to get detection information. The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, an angular velocity sensor, a hexaaxial sensor, an IMU (Inertial Measurement Unit), and the like. Also, the boom angle sensor S1 may include a cylinder sensor capable of detecting the telescopic position of the boom cylinder 7 .

The arm angle sensor S2 (an example of a second acquisition device) detects the arm 5 with respect to a predetermined reference (for example, a straight line connecting the connecting points at both ends of the boom 4, or any state at either end of the movable angle range of the arm 5, etc.). acquires detection information about the attitude angle of the arm (hereinafter referred to as the “arm angle”). Arm angle sensor S2 may include, for example, a rotary encoder, an acceleration sensor, an angular velocity sensor, a hexaaxial sensor, an IMU, or the like. Also, the arm angle sensor S2 may include a cylinder sensor capable of detecting the extension/retraction position of the arm cylinder 8 .

The bucket angle sensor S3 (an example of a second acquisition device) detects the value of the bucket 6 with respect to a predetermined reference (for example, a straight line connecting the connection points at both ends of the arm 5, or any state at either end of the movable angle range of the bucket 6, etc.). acquires detection information about the attitude angle of (hereinafter, “bucket angle”). Bucket angle sensor S3 may include, for example, a rotary encoder, an acceleration sensor, an angular velocity sensor, a hexaaxial sensor, an IMU, and the like. Also, the bucket angle sensor S3 may include a cylinder sensor capable of detecting the expansion/contraction position of the bucket cylinder 9 .

The aircraft attitude sensor S4 (an example of the second acquisition device) acquires detection information regarding the attitude state of the aircraft including the lower traveling body 1 and the upper rotating body 3 . The attitude state of the airframe includes the tilt state of the airframe. The tilted state of the fuselage includes, for example, a tilted state in the longitudinal direction, which corresponds to the posture state of the upper rotating body 3 about the lateral axis, and a tilted state in the lateral direction, which corresponds to the posture state of the upper rotating body 3 about the longitudinal axis. state is included. In addition, the attitude state of the machine body may include the turning state of the upper turning body 3 , which corresponds to the attitude state of the upper turning body 3 about the turning axis. The machine body attitude sensor S4 is mounted, for example, on the upper revolving structure 3, and obtains detection data regarding the attitude angles of the upper revolving structure 3 about the longitudinal axis and the lateral axis (hereinafter referred to as "forward/backward tilt angle" and "lateral tilt angle"). (Output. Further, detection data relating to the posture angle around the turning axis may be acquired (output). As a result, the body posture sensor S4 can acquire detection information regarding the orientation of the upper swing body 3 with respect to the ground (the swing posture about the swing axis). The orientation of the upper revolving body 3 means, for example, the direction in which the attachment AT extends when viewed from above, that is, the front as viewed from the upper revolving body 3 . The airframe attitude sensor S4 may include, for example, an acceleration sensor (tilt sensor), an angular velocity sensor, a hexaaxial sensor, an IMU, and the like.

Information about the orientation of the upper rotating body 3 with respect to the ground may be obtained from another device instead of or in addition to the body attitude sensor S4. For example, a geomagnetic sensor may be mounted on the upper revolving body 3 . In this case, the controller 30 can acquire information about the orientation of the upper swing structure 3 with respect to the ground from the geomagnetic sensor. Further, for example, the controller 30 determines the direction in which surrounding objects (in particular, fixed objects such as utility poles and trees) are present based on the output (captured image) of the imaging device S6. 3 may be determined with respect to the ground. That is, the information about the orientation of the upper rotating body 3 with respect to the ground may be obtained from the imaging device S6.

The turning angle sensor S5 acquires detection information regarding the relative turning angle of the upper turning body 3 with the lower traveling body 1 as a reference. As a result, the turning angle sensor S5 acquires, for example, detection information about the turning angle of the upper turning body 3 with respect to a predetermined reference (for example, a state in which the forward direction of the lower traveling body 1 and the front of the upper turning body 3 match). . The turning angle sensor S5 includes, for example, a potentiometer, rotary encoder, resolver, and the like.

Incidentally, it may be simply assumed that the orientation of the upper revolving structure 3 with respect to the ground and the orientation of the upper revolving structure 3 with respect to the lower traveling structure 1 are substantially the same. In this case, the turning angle sensor S5 may be omitted.

Further, for example, the excavator 100 may be further equipped with a positioning device capable of positioning the absolute position of the excavator 100 . The positioning device is, for example, a GNSS (Global Navigation Satellite System) sensor. Thereby, the estimation accuracy of the posture state of the excavator 100 can be improved. A GNSS sensor may also be used to obtain information about the orientation of the upper swing structure 3 with respect to the ground. In this case, the controller 30 can obtain information about the orientation of the upper slewing structure 3 with respect to the ground from two or more GNSS sensors installed at different positions on the upper slewing structure 3 .

The imaging device S6 (an example of the first acquisition device) captures the surroundings of the excavator 100 and outputs the captured image. A captured image output from the imaging device S6 is captured by the controller 30 .

The imaging device S6 includes, for example, a monocular camera, a stereo camera, a depth camera, and the like. In addition, the imaging device S6 acquires three-dimensional data (for example, point cloud data or surface data) representing the position and outline of an object around the excavator 100 within a predetermined imaging range (angle of view) based on the captured image. may

Further, instead of or in addition to the imaging device S6, the excavator 100 may be equipped with a distance sensor such as a LIDAR (Light Detecting and Ranging), a millimeter wave radar, an ultrasonic sensor, an infrared sensor, or a distance image sensor. good. The range sensor may acquire three-dimensional data (eg, point cloud data) representing the position and shape of objects around excavator 100 within a predetermined detection range.

As shown in FIG. 1, the imaging device S6 is attached to, for example, the front end of the upper surface of the cabin 10, and acquires a captured image in front of the upper rotating body 3 including the working range of the end attachment (the bucket 6). Thereby, the controller 30 can recognize the situation in front of the excavator 100 based on the output of the imaging device S6. In addition, the controller 30 determines the position of the excavator 100, the turning state of the upper turning body 3, and the like based on changes in the positions and appearances of objects around the excavator 100 recognized from the output (captured image) of the imaging device S6. can recognize. Moreover, the imaging range of the imaging device S6 includes the boom 4, the arm 5, and the end attachment (bucket 6), that is, the attachment AT. Thereby, the controller 30 can recognize the attitude state of the attachment (for example, the attitude angle of at least one of the boom 4, the arm 5, and the bucket 6) based on the output of the imaging device S6. Therefore, when the excavator 100 is remotely operated, the controller 30 transmits information about the peripheral image and various recognition results based on the imaging device S6 to the external device, and informs the external operator of the excavator 100 (own machine) and its peripheral. Can provide information about the situation. Further, when the excavator 100 operates with the fully automatic operation function, the control device (for example, the controller 30) related to the fully automatic operation function grasps the surrounding conditions of the excavator 100, the attitude state of the excavator itself, and the hydraulic actuator. It is possible to output operation commands related to In addition, when the excavator 100 operates with the fully automatic operation function, the controller 30 transmits peripheral images based on the imaging device S6 and information about various recognition results to an external device, and a user (monitor) who monitors the work from the outside. ) can be provided with information about the excavator 100 (self) and its surroundings.

Further, the imaging device S6 may be configured to be capable of acquiring a captured image of at least one of the left side, right side, and rear side of the upper rotating body 3 . Specifically, the imaging device S6 includes a camera capable of imaging the front of the upper rotating body 3, a camera capable of imaging the left side of the upper rotating body 3, a camera capable of imaging the right side of the upper rotating body 3, and a camera capable of imaging the rear side. At least one of the possible cameras may be included. Thereby, the controller 30 can recognize not only the situation in front of the excavator 100 (upper revolving body 3) but also the left, right and rear conditions of the excavator 100 (upper revolving body 3).

Incidentally, in this example, the imaging device S6, the distance sensor, and the like may be omitted.

The attitude measurement unit 301 measures the attitudes of the body of the excavator 100 and the attachment AT. For example, the posture measurement unit 301 performs a predetermined control cycle (hereinafter simply referred to as “control cycle ”), the attitudes of the body of the shovel 100 and the attachment AT are measured in real time. "Real-time" means that, based on the latest outputs of the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, and aircraft attitude sensor S4 at the start of the target control cycle, the aircraft and attachment It means to measure the posture of AT.

The posture measurement unit 301 measures (calculates) the posture angle of the boom 4 based on the output of the boom angle sensor S1, for example. Similarly, the posture measurement unit 301 measures (calculates) the posture angle of the arm 5 based on the output of the arm angle sensor S2, for example. Similarly, the attitude measurement unit 301 measures (calculates) the attitude angle of the bucket 6 based on the output of the bucket angle sensor S3, for example. In addition, the attitude measurement unit 301 measures (calculates) the attitude angles (front-rear tilt angle, left-right tilt angle, and turning angle) of the upper revolving structure 3 based on the output of the machine body attitude sensor S4, for example.

The earth and sand volume estimator 302 estimates the volume of earth and sand that applies a load to the bucket 6 from above when the shovel 100 excavates. The soil volume estimation unit 302, for example, estimates in real time the volume of soil that applies a load to the bucket 6 from above, based on the posture of the excavator 100 and the attachment AT of the excavator 100 measured by the posture measurement unit 301 in each control cycle. do. “Real time” means estimating the volume of earth and sand during the control period based on the measurement result of the attitude measurement unit 301 in the target control period. Details will be described later (see FIG. 3).

The stability evaluation unit 303 evaluates (estimates) the stability of the posture of the excavator 100 . For example, the stability evaluation unit 303 adjusts the excavator 100 based on the attitude of the attachment AT and the machine body of the excavator 100 measured by the attitude measurement unit 301 and the volume of earth and sand estimated by the earth and sand volume estimation unit 302 in each control cycle. The stability of the posture of the robot is evaluated in real time. “Real time” means evaluating the stability of the excavator 100 during the control cycle based on the measurement result of the posture measurement unit 301 and the estimation result of the sediment volume estimation unit 302 in the target control cycle.

The stability of the posture of the excavator 100 is an index representing how difficult it is for the excavator 100 to transition to a predetermined unstable state. Specifically, it is an index representing the difficulty of overturning of the excavator 100 . For example, the stability evaluation unit 303 determines (evaluates) that the stability of the posture of the excavator 100 is relatively high and that the posture of the excavator 100 is in a stable state when the possibility of the excavator 100 overturning is relatively low. You can On the other hand, the stability evaluation unit 303 determines (evaluates) that the stability of the posture of the excavator 100 is relatively low and the posture of the excavator 100 is unstable when the possibility of the excavator 100 tipping over is relatively high. ). Further, when the stability of the excavator 100 is declining at a relatively high speed, the stability evaluation unit 303 determines that the posture of the excavator 100 is highly likely to shift to an unstable state, and the posture of the excavator 100 is unstable. It may be determined (evaluated) that there is a high possibility of transitioning to the state. Details of the stability evaluation method will be described later (see FIGS. 3 and 4).

The overturn prevention control unit 304 performs control (overturn prevention control) to prevent the excavator 100 from overturning based on the evaluation result of the posture stability of the excavator 100 by the stability evaluation unit 303 . Specifically, when the stability evaluation unit 303 evaluates that the posture of the excavator 100 is in an unstable state, or evaluates that the posture of the excavator 100 is highly likely to shift to an unstable state, the overturn prevention control unit 304 In addition, overturn prevention control may be performed.

The overturn prevention control unit 304 may use the output device 50, for example, to warn the operator that the excavator 100 may overturn. Specifically, the overturn prevention control unit 304 outputs a control command to the display device 50A, and image information (for example, text information, a specific icon image, etc.) representing a warning that the excavator 100 may overturn. may be displayed on the display device 50A. In addition, the overturn prevention control unit 304 may output a control command to the sound output device 50B to cause the sound output device 50B to output a warning sound or voice information indicating that the excavator 100 may overturn. Thereby, the controller 30 can warn the operator that the excavator 100 may overturn and prompt the operator to stop operating the attachment AT of the excavator 100 .

Further, when the excavator 100 is remotely controlled or remotely monitored, the overturn prevention control unit 304, for example, sends a signal indicating that the excavator 100 may overturn to an external device (for example, a management device, etc.). may be sent. As a result, the controller 30 can warn the operator or the observer that the excavator 100 may tip over through the display device or the sound output device in the external device. Therefore, the controller 30 can prompt the remote operator to stop the excavator 100 or prompt the remote monitoring supervisor to operate the excavator 100 for emergency stop.

In addition, the overturn prevention control unit 304 may limit the operation of the attachment AT of the excavator 100 using the hydraulic control valve 31, for example. The restriction on the operation of the attachment AT includes a control mode in which the attachment AT is not operated in response to the operation of the attachment AT, that is, the attachment AT is forcibly stopped. In addition, the limitation of the operation of the attachment AT includes a control mode of reducing the operation speed of the attachment AT relative to the operation of the attachment AT.

Further, the overturn prevention control unit 304 determines whether the excavator 100 is evaluated to be in an unstable state by the stability evaluation unit 303 or when it is evaluated that the excavator 100 may shift to an unstable state. You may change the aspect (specification) of fall prevention control.

For example, when the stability evaluation unit 303 evaluates that the excavator 100 may shift to an unstable state, the overturn prevention control unit 304 warns the operator or the like and limits the operation of the attachment AT. only As a result, the controller 30 can alert the operator or the like that the posture of the excavator 100 is not in an unstable state but is highly likely to shift to an unstable state. On the other hand, when the stability evaluation unit 303 evaluates that the excavator 100 is in an unstable state, the overturn prevention control unit 304 limits the operation of the attachment AT instead of or in addition to warning the operator. you can As a result, the controller 30 can forcibly limit the operation of the attachment AT when the posture of the excavator 100 is unstable, thereby increasing the possibility of preventing the excavator 100 from overturning forward.

Further, for example, when the stability evaluation unit 303 evaluates that the excavator 100 may shift to an unstable state, the overturn prevention control unit 304 decelerates the operation of the attachment AT in response to the operation of the attachment AT. you can As a result, the controller 30 can suppress the transition of the posture of the excavator 100 to an unstable state while minimizing a decrease in the work efficiency of the excavator 100 . On the other hand, when the stability evaluation unit 303 evaluates that the excavator 100 may shift to an unstable state, the overturn prevention control unit 304 operates the attachment AT regardless of whether the attachment AT is operated. You can stop it. As a result, the controller 30 forcibly restricts the operation of the attachment AT when the posture of the excavator 100 has shifted to an unstable state, thereby increasing the possibility of preventing the excavator 100 from overturning forward. can be done.

Note that, when the operation of the attachment AT is stopped, the overturn prevention control unit 304 may permit the operation of the attachment AT in a direction in which the stability of the attitude of the excavator 100 is relatively high. Accordingly, the operator or the like can operate the attachment AT so as to return the posture of the excavator 100 from the unstable state to the stable state.

In addition, the overturn prevention control unit 304 cancels (stops) overturn prevention control when a predetermined operation for canceling the overturn prevention control (warning the operator or restricting the operation of the excavator 100) is performed through the input device 52. ) can be released. The overturn prevention control unit 304 cancels (stops) overturn prevention control when the stability evaluation unit 303 evaluates that the unstable state of the posture of the excavator 100 is resolved and the posture of the excavator 100 is stable. you can

[An example of a method for evaluating the stability of the posture of an excavator]
Next, with reference to FIG. 3, an example of a method for evaluating the posture stability of the excavator 100 will be described. In this example, the stability evaluation unit 303 evaluates the stability of the posture of the excavator 100 based on the possibility of the excavator 100 overturning due to the load (gravity) acting statically on the excavator 100 .

FIG. 3 is a diagram illustrating an example of a method for evaluating the stability of the attitude of the shovel 100. As shown in FIG. Specifically, FIG. 3 is a diagram showing the earth and sand lifting operation by the attachment AT in the excavation process of the shovel 100. As shown in FIG.

As shown in FIGS. 3A and 3B, when the excavator 100 lifts the earth and sand using the bucket 6 in the latter half of the excavation process, a load F _s corresponding to the weight of the earth and sand existing on the bucket 6 is applied. acts on bucket 6. Therefore, when the excavator 100 lifts the bucket 6, a load _Fs of earth and sand acts on the bucket 6 from above, and the excavator 100 moves forward with the front end (overturning fulcrum FL) of the ground contact portion of the lower traveling body 1 of the excavator 100 as a reference. A moment in the direction of overturning (hereinafter referred to as "overturning promoting moment") _Ms acts. The overturning assisting moment M _s is obtained by multiplying the horizontal distance L _s between the overturning fulcrum FL and the point of application of the earth load F _s to the bucket 6 by the load F _s (M _s =F _s ·L _s ).

The controller 30 (stability evaluation unit 303) can acquire (calculate) the load _Fs by multiplying the volume of the sediment estimated by the sediment volume estimation unit 302 and the density of the sediment. Information about the density of soil at the work site may be received from the management device through the communication device 60 and stored in the storage device 47, for example. Thereby, the stability evaluation unit 303 can acquire (calculate) the load _Fs .

As shown in FIG. 3( a ), the earth and sand volume estimator 302 may estimate the volume of earth and sand located directly above the bucket 6 . In addition, as shown in FIG. 3B, the earth and sand volume estimator 302 may estimate the volume of earth and sand located in the moving direction of the bucket 6 (white arrow pointing diagonally upward to the left in the figure). The same may be applied to other examples described later.

Specifically, first, the earth and sand volume estimation unit 302 acquires (calculates) the position information of the bucket 6 based on the measurement result of the posture measurement unit 301 and the information on the specifications of the boom 4, the arm 5, and the bucket 6. ). Information about the specifications of the boom 4, the arm 5, and the bucket 6 is registered (stored) in advance in the storage device 47, for example. The information about the specifications of the boom 4, the arm 5, and the bucket 6 includes, for example, the distance between the axes between the base end and the tip of the boom 4, the distance between the axes between the base end and the tip of the arm 5, the bucket 6 shape information and the like.

Then, the earth and sand volume estimation unit 302 grasps the shape (topography) of the ground in front of the excavator 100 based on the survey data in the storage device 47, and based on the acquired relationship between the position information of the bucket 6 and the topography, You may estimate the volume of the earth and sand to which a load acts from above. As a result, when considering the moving direction of the _bucket 6, the earth and sand volume estimation unit 302 uses the position information of the bucket 6 in the current control cycle and the position information of the bucket 6 in the previous control cycle as Based on this, the moving direction of the bucket 6 may be acquired (calculated). Thereby, the earth and sand volume estimator 302 can estimate the volume of the earth and sand positioned in the moving direction of the bucket 6 .

Further, the stability evaluation unit 303 may acquire the position information of the bucket 6 with the body as a reference based on the intermediate calculation result of the earth and sand volume estimation unit 302 . Thereby, the stability evaluation unit 303 can acquire the position information of the point of action of the load _Fs on the bucket 6 .

In addition, the stability evaluation unit 303 grasps the orientation of the lower traveling body 1 with the upper rotating body 3 as a reference based on the output of the machine body attitude sensor S4 or the turning angle sensor S5 and the information on the specifications of the lower traveling body 1. Then, the positional information of the front end (falling fulcrum FL) of the ground contact portion of the undercarriage 1 may be acquired (calculated). Information about the specifications of the undercarriage 1 is stored in advance in the storage device 47, for example. The information on the specifications of the undercarriage 1 includes, for example, information on various dimensions between the turning center and the outer edge of the ground contact portion when the undercarriage 1 is viewed from above. Thereby, the stability evaluation unit 303 can obtain (calculate) the horizontal distance _Ls between the tipping fulcrum FL and the point of action of the load _Fs of earth and sand on the bucket 6 . Therefore, the stability evaluation unit 303 can acquire (calculate) the overturning assisting moment _Ms based on the calculation results of the load _Fs and the distance _Ls .

On the other hand, the center of gravity G of the excavator 100 is located behind the front end (overturning fulcrum FL) of the ground contact portion of the lower traveling body 1 of the excavator 100 . Therefore, the load F _exc , which corresponds to the weight of the excavator 100 , acts on the excavator 100 to exert a moment M _exc (hereinafter referred to as “overturn prevention moment”) in a direction to prevent the excavator 100 from overturning forward. The overturning suppression moment M _exc is obtained by multiplying the horizontal distance L _exc between the overturning fulcrum FL and the position of the center of gravity G by the load F _exc corresponding to the weight of the excavator 100 (M _exc =F _{excL exc} ).

The stability evaluation unit 303 may acquire (calculate) the position of the center of gravity based on the attitudes of the airframe, the boom 4 , the arm 5 and the bucket 6 measured by the attitude measurement unit 301 . Then, the stability evaluation unit 303 may acquire the position information of the center of gravity G of the shovel 100 based on the weights and the positions of the centers of gravity of the machine body, boom 4 , arm 5 and bucket 6 . Information about the weight of the excavator 100 is registered (stored) in advance in the storage device 47, for example. As a result, using the information on the positions of the tipping fulcrum FL and the center of gravity G, the horizontal distance L _exc between the tipping fulcrum FL and the position of the center of gravity G can be obtained (calculated). Therefore, the stability evaluation unit 303 can acquire (calculate) the overturning prevention moment M _exc based on the calculation result of the load F _exc that corresponds to the weight of the excavator 100 and the distance L _exc .

The stability evaluation unit 303 evaluates the stability of the excavator 100 based on the relationship between the overturn-promoting moment _{Ms and the overturn-preventing moment Mexc .}

For example, the stability evaluation unit 303 evaluates that the excavator 100 is in a stable state when the overturning prevention moment M _exc is greater than the overturning assisting moment _Ms , that is, when the following formula (1) holds.

On the other hand, the stability evaluation unit 303 evaluates that the excavator 100 is in an unstable state, for example, when the overturning prevention moment M _exc is equal to or less than the overturning assisting moment _Ms , that is, when the following formula (2) holds. do.

Further, the stability evaluation unit 303, for example, when the posture of the excavator 100 is in a stable state and the stability of the posture of the excavator 100 is declining at a relatively high speed, that is, the above equation (1 ) and a predetermined threshold value Th (<0), it may be evaluated that there is a high possibility that the excavator 100 shifts to an unstable state.

Thus, in this example, the controller 30 estimates the volume of earth and sand to be lifted by the attachment AT using the bucket 6, and based on the estimated volume of earth and sand, the attitude of the fuselage including the lower traveling body 1 and the upper rotating body 3 is determined. to assess the stability of

Thereby, the controller 30 can evaluate the stability of the posture of the excavator 100 even before the body actually tilts. Therefore, for example, the controller 30 can grasp the unstable state of the excavator 100 before the rear part of the lower traveling body 1 of the excavator 100 is lifted up, and can perform overturn prevention control of the excavator 100 in advance. can.

In addition, in this example, the controller 30 estimates the volume of earth and sand that applies a load to the bucket 6 from above based on the outputs of the sensors S1 to S4 and the survey data acquired (captured) from the outside by the communication device 60. do.

Thereby, the controller 30 can specifically estimate the volume of the earth and sand that applies the load to the bucket 6 from above.

Also, in this example, the controller 30 estimates the volume of earth and sand to which the load is applied from above the bucket 6 based on the moving direction of the bucket 6 .

Thereby, the controller 30 can more appropriately estimate the volume of the earth and sand to which the load is applied from above the bucket 6 .

[Another example of evaluation method for stability of excavator posture]
Next, another example of the stability evaluation method of the excavator 100 will be described with reference to FIG. In this example, the stability evaluation unit 303 evaluates the excavator 100 based on the possibility of overturning of the excavator 100 taking into account both the static load (gravitational force) and the dynamic load (inertial force) acting on the excavator 100. 100 postural stability is assessed.

FIG. 4 is a diagram illustrating another example of a method of evaluating the stability of the posture of the excavator 100. In FIG. Specifically, FIG. 4A is a diagram showing an example of a zero moment point (ZMP: Zero Moment Point) of the shovel 100. As shown in FIG. FIG. 4(b) is a diagram showing an example of gravity and inertial force acting on the excavator 100 when the attachment AT lifts the earth and sand in the excavation process of the excavator 100. As shown in FIG.

In this example, the intersection of the turning axis of the upper revolving body 3 of the excavator 100 and the ground is set as the origin, and the longitudinal axis, the lateral axis, and the revolving axis of the upper revolving body 3 are the x-axis, the y-axis, and the revolving axis, respectively. The zero moment point is treated on the xyz coordinates with the z axis.

In this example, the controller 30 (stability evaluation unit 303) calculates the zero moment point of the excavator 100 and evaluates the stability of the posture of the excavator 100 based on the calculated zero moment point. The zero moment point means the point where the direction of the resultant force of gravity and inertia acting on the excavator 100 intersects the ground.

As shown in FIG. 4( a ), when the zero moment point (point 401 in the figure) is within the range of the ground contact area 402 of the undercarriage 1 , the resultant force of gravity and inertial force acting on the excavator 100 causes The moment does not cause the excavator 100 to tip over. On the other hand, if the zero moment point is outside the ground contact area 402 , the excavator 100 may tip over due to the resultant moment of the gravitational and inertial forces acting on the excavator 100 . The ground contact areas 402 are located at both end positions of the lower traveling body 1 in the width direction, specifically, the left end position of the left crawler 1C, the right end position of the right crawler 1C, and the ground contact portion of the lower traveling body 1 in the traveling direction. It is a substantially rectangular area defined by the positions of both ends.

As shown in FIG. 4(b), the forces (gravitational force and inertial force) acting on the excavator 100 are calculated from the lower traveling body 1, the upper revolving body 3, the boom 4, the arm 5, the bucket 6, and from above by mass point approximation. It is approximated by the forces acting on each of the soils that load the bucket 6 . The stability evaluator 303 can apply mass point approximation and compute the x and y coordinates (x _ZMP , y _ZMP ) of the zero moment point using equations (4) and (5) below.

The suffix i is an integer from 0 to 5, and each value acts on the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, the bucket 6, and the bucket 6 from above in order. correspond to each of the sediments that cause

Information about the position of the mass point (center of gravity) and the mass in each configuration of the lower traveling body 1, the upper rotating body 3, the boom 4, the arm 5, and the bucket 6 is pre-registered (stored) in the storage device 47, for example. ) is done. Since the mass points of the lower traveling body 1 and the upper revolving body 3 are targeted for excavation, it is assumed that the upper revolving body 3 is not revolving. is uniquely determined based on the relative swivel angle between and the upper swivel body 3 . Further, the accelerations of the lower traveling body 1 and the upper revolving body 3 are assumed to be zero because they are intended for excavation. Further, the positions of the mass points of the boom 4 , the arm 5 , and the bucket 6 with respect to the machine body are acquired (calculated) based on the measurement result of the attitude measurement unit 301 . Further, the acceleration of each mass point of the boom 4, arm 5, and bucket 6 is acquired (calculated) based on the output of the acceleration sensor, angular velocity sensor, IMU, six-axis sensor, etc. included in each of the sensors S1 to S3, for example. be done. Also, the mass of the earth and sand that applies the load to the bucket 6 from above is acquired (calculated) based on the estimation result of the earth and sand volume estimation unit 302, as in the case of the above example. Also, the mass point of the earth and sand that applies the load to the bucket 6 from above may be obtained, for example, by calculating the geometric centroid under the assumption that the density of the earth and sand is constant. Also, the acceleration of the mass point of the earth and sand that applies the load to the bucket 6 from above may be regarded as equivalent to the acceleration of the bucket 6 . Thereby, the stability evaluation unit 303 can obtain (calculate) the zero moment point of the excavator 100 using the equation (4).

For example, when the zero moment point is within the ground contact area, the stability evaluation unit 303 evaluates (determines) that the excavator 100 is unlikely to overturn forward and that the posture of the excavator 100 is stable.

On the other hand, for example, when the zero moment point is outside the installation area, the stability evaluation unit 303 evaluates (determines) that the excavator 100 is likely to tip over forward and that the posture of the excavator 100 is unstable. )do.

Further, as in the case of the above example, the stability evaluation unit 303, for example, when the speed toward the outside of the ground contact area of the zero moment point is relatively high (specifically, is equal to or greater than a predetermined threshold), the excavator It may be evaluated that the posture of 100 has a high possibility of transitioning to an unstable state.

As described above, in this example, the controller 30 estimates the volume of earth and sand to be lifted by the attachment AT using the bucket 6, and calculates the volume of the undercarriage 1 based on the estimated volume of earth and sand, as in the case of the first example described above. and the attitude stability of the airframe including the upper revolving structure 3.

As a result, the controller 30 can evaluate the stability of the attitude of the shovel 100 even before the machine body actually tilts, as in the example described above. Therefore, for example, the controller 30 can grasp the unstable state of the excavator 100 before the rear part of the lower traveling body 1 of the excavator 100 is lifted up, and can perform overturn prevention control of the excavator 100 in advance. can.

Further, in this example, the controller 30 evaluates the stability of the posture of the excavator 100 based on the acceleration of the boom 4, the arm 5, the bucket 6, and the earth and sand that apply the load to the bucket 6 from above.

As a result, the controller 30 considers not only the gravitational force acting on the excavator 100 but also the inertial force acting on the excavator 100 due to the operation of the attachment AT, and determines the dynamic attitude stability of the body of the excavator 100. can be evaluated.

The controller 30 (stability evaluation unit 303) may evaluate the stability of the body posture of the shovel 100 by combining the evaluation methods of the above example and this example.

[Another example of excavator configuration]
Next, another example of the configuration of the excavator 100 according to this embodiment will be described with reference to FIG.

FIG. 5 is a block diagram showing another example of the configuration of the shovel 100 according to this embodiment. The following description will focus on portions that differ from the above example (FIG. 2).

The shovel 100 of this example differs from the example described above in that at least one of the imaging device S6 and the distance sensor is essential and the survey data in the storage device 47 is omitted.

In this example, unlike the example described above, the controller 30 (sediment volume estimation unit 302) uses the output of at least one of the imaging device S6 and the distance sensor (an example of topographical information) instead of the survey data to determine the excavator 100 Grasp the surrounding terrain. As a result, the earth and sand volume estimating unit 302 applies a load to the bucket 6 from above based on the terrain in front of the excavator 100 and the position information of the bucket 6, which are grasped from the output of the imaging device S6 and the distance sensor. Volume can be estimated.

In this example, the stability evaluation unit 303 employs any one of the example (FIG. 3) and the other example (FIG. 4) of the evaluation method described above to evaluate the stability of the body posture of the shovel 100. you can Further, the stability evaluation unit 303 may evaluate the stability of the body posture of the shovel 100 by combining one example of the evaluation method described above and another example.

Thus, in this example, the controller 30 uses the outputs of the sensors S1 to S4 and the output of the imaging device S6 that captures an image of the surroundings of the excavator 100 or the output of the distance sensor that measures the distance to an object in the vicinity of the excavator 100. Based on this, the volume of earth and sand that causes the load to act on the bucket 6 from above is estimated.

Thereby, the controller 30 can specifically estimate the volume of the earth and sand that applies the load to the bucket 6 from above.

Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the claims.

1 Lower Traveling Body 1C Crawler 1ML, 1MR Traveling Hydraulic Motor 2A Revolving Hydraulic Motor 3 Upper Revolving Body 4 Boom 5 Arm 6 Bucket 7 Boom Cylinder 8 Arm Cylinder 9 Bucket Cylinder 11 Engine 14 Main Pump 17 Control Valve 30 Controller (Control Device)
50 output device 50A display device 50B sound output device 52 input device 60 communication device (first acquisition device)
100 excavator AT attachment (work attachment)
S1 boom angle sensor (second acquisition device)
S2 arm angle sensor (second acquisition device)
S3 bucket angle sensor (second acquisition device)
S4 airframe attitude sensor (second acquisition device)
S5 turning angle sensor S6 imaging device (first acquisition device)

Claims (6)

a lower running body;
an upper rotating body rotatably mounted on the lower traveling body;
a work attachment attached to the upper rotating structure and including a boom, an arm, and a bucket;
a control device for estimating the volume of earth and sand to be lifted by the work attachment using the bucket, and evaluating the stability of the attitude of the machine body including the lower traveling body and the upper rotating body based on the estimated volume of earth and sand; prepare
Excavator. a first acquisition device for acquiring information about terrain around the excavator;
a second acquisition device that acquires information about the posture of the work attachment;
The control device estimates the volume of the earth and sand based on the information about the terrain and the information about the posture of the work attachment.
Shovel according to claim 1 . The control device evaluates the stability of the attitude of the aircraft based on the acceleration of the boom, the arm, the bucket, and the earth and sand.
A shovel according to claim 1 or 2. The control device estimates the volume of the earth and sand based on the movement direction of the bucket.
Shovel according to any one of claims 1 to 3. The first acquisition device externally acquires survey data of a work site as information about the topography,
Shovel according to claim 2. The first acquisition device is an imaging device that captures an image around the excavator, or a distance sensor that measures the distance to an object around the excavator.
Shovel according to claim 2.

Images