Excavator

Abstract

To improve work efficiency.SOLUTION: A shovel has a lower traveling body, an upper revolving body, a hydraulic actuator mounted on the upper revolving body, and a control unit that controls the hydraulic actuator according to the state of the earth and sand in a bucket after excavation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a shovel. [Background technology]

[0002] Conventionally, there is known an excavator that generates a movement trajectory line based on the relative positional relationship between the position (posture) of the bucket and the position of an object such as a dump truck, and controls the boom and upper rotating body along the movement trajectory line to make it easier to stop the bucket at the loading position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 115809 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional technology described above, when loading the soil and sand from the bucket onto the bed of a dump truck or the like, the soil and sand loaded in the bucket may spill due to the shaking of the bucket, etc. If a spill occurs, for example, cleaning work of the surrounding area is required, which reduces work efficiency.

[0005] In view of the above circumstances, the object is to improve work efficiency. [Means for solving the problem]

[0006] The excavator according to an embodiment of the present invention includes a lower traveling section, an upper rotating body, a hydraulic actuator mounted on the upper rotating body, A space recognition device, a gravity center calculation unit that calculates the gravity center of the soil in the bucket, and the shape of the image of the soil in the bucket acquired by the space recognition device and the position of the gravity center of the soil in the bucket.The excavator has a condition determination unit that acquires information indicating the condition of the soil and sand and determines that the condition of the soil and sand is prone to spillage if the condition of the soil and sand satisfies predetermined conditions; a control unit that controls a hydraulic actuator according to the condition of the soil and sand in the bucket after excavation; and a weight calculation unit that calculates the weight of the soil and sand in the bucket, wherein the condition determination unit determines the condition of the soil and sand when the bucket after excavation has been raised to a predetermined height, and the weight calculation unit calculates the weight of the soil and sand in the bucket when the bucket has been raised to the predetermined height after the condition of the soil and sand has been determined by the condition determination unit. [Effects of the Invention]

[0007] Work efficiency can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a side view of the shovel of the present embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of a configuration of a shovel according to an embodiment of the present invention. [Figure 3] 1 is a diagram illustrating an example of a configuration of a hydraulic system of a shovel according to an embodiment of the present invention. [Figure 4A] FIG. 1 is a diagram of a portion of the hydraulic system for operating the arm cylinder. [Figure 4B] FIG. 2 is a diagram of a portion of the hydraulic system for the boom cylinder. [Figure 4C] FIG. 2 is a diagram of a portion of the hydraulic system for the bucket cylinder. [Figure 4D] FIG. 1 is a diagram of a portion of a hydraulic system for a swing hydraulic motor. [Figure 5] FIG. 2 is a diagram illustrating an example of components related to a soil weight detection function of the shovel according to the present embodiment. [Figure 6] FIG. 10 is a schematic diagram illustrating parameters related to calculation of soil weight. [Figure 7] FIG. 10 is a diagram illustrating the center of gravity of soil in a bucket. [Figure 8] FIG. 10 is a diagram illustrating the shape of soil and sand in a bucket. [Figure 9] 10A and 10B are diagrams illustrating control by a suppression control unit. [Figure 10] FIG. 1 is a diagram showing an example of a work site where a dump truck is being loaded with earth and sand by a shovel. [Figure 11] 10 is a flowchart illustrating the processing of the soil weight processing unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the invention will be described with reference to the drawings.

[0010] First, an overview of a shovel 100 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a side view of the shovel 100 as an excavator according to this embodiment.

[0011] In FIG. 1, an example of a target trajectory BS (to be described later) of the shovel 100 is also depicted on the upward slope ES of the excavation target.

[0012] The excavator 100 according to this embodiment comprises a lower running body 1, an upper rotating body 3 mounted on the lower running body 1 so as to be freely rotatable via a rotating mechanism 2, a boom 4, an arm 5, and a bucket 6 constituting attachments, and a cabin 10.

[0013] The lower traveling body 1 has a pair of left and right crawlers that are hydraulically driven by hydraulic traveling motors 1L, 1R (see FIG. 2, which will be described later), thereby causing the excavator 100 to travel. In other words, the pair of hydraulic traveling motors 1L, 1R (an example of a traveling motor) drive the lower traveling body 1 (crawlers) as a driven part.

[0014] The upper rotating body 3 is driven by a hydraulic swing motor 2A (see FIG. 2 described later) to rotate relative to the lower traveling body 1. In other words, the hydraulic swing motor 2A is a swing drive part that drives the upper rotating body 3 as a driven part, and can change the orientation of the upper rotating body 3.

[0015] The upper rotating body 3 may be electrically driven by an electric motor (hereinafter referred to as "swing electric motor") instead of the swing hydraulic motor 2A. In other words, the swing electric motor is a swing drive part that drives the upper rotating body 3 as a non-drive part, similar to the swing hydraulic motor 2A, and can change the orientation of the upper rotating body 3.

[0016] A boom 4 is pivotally attached to the front center of the upper rotating body 3 so as to be able to tilt up and down, an arm 5 is pivotally attached to the tip of the boom 4 so as to be able to rotate up and down, and a bucket 6 serving as an end attachment is pivotally attached to the tip of the arm 5 so as to be able to rotate up and down. The boom 4, arm 5, and bucket 6 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, each serving as a hydraulic actuator.

[0017] The bucket 6 is an example of an end attachment, and other end attachments, such as a slope bucket, a dredging bucket, or a breaker, may be attached to the tip of the arm 5 instead of the bucket 6, depending on the work content, etc.

[0018] The cabin 10 is a cab in which an operator sits, and is mounted on the front left side of the upper rotating body 3.

[0019] Next, a specific configuration of the shovel 100 according to this embodiment will be described with reference to FIG.

[0020] FIG. 2 is a diagram schematically showing an example of the configuration of the shovel 100 according to this embodiment.

[0021] In FIG. 2, the mechanical power system, hydraulic oil lines, pilot lines, and electrical control system are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively.

[0022] The drive system of the excavator 100 according to this embodiment includes the engine 11, the regulator 13, the main pump 14, and the control valve 17. Furthermore, the hydraulic drive system of the excavator 100 according to this embodiment includes hydraulic actuators such as the traveling hydraulic motors 1L, 1R, the swing hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 that hydraulically drive the lower traveling structure 1, the upper rotating structure 3, the boom 4, the arm 5, and the bucket 6, respectively, as described above.

[0023] The engine 11 is the main power source in the hydraulic drive system, and is mounted, for example, on the rear of the upper rotating body 3. Specifically, the engine 11 rotates at a constant speed at a preset target speed under direct or indirect control by a controller 30 (described later), and drives the main pump 14 and the pilot pump 15. The engine 11 is, for example, a diesel engine that uses diesel as fuel.

[0024] The regulator 13 controls the discharge amount of the main pump 14. For example, the regulator 13 adjusts the angle (tilt angle) of the swash plate of the main pump 14 in response to a control command from the controller 30. The regulator 13 includes, for example, regulators 13L and 13R, as described below.

[0025] The main pump 14 is mounted, for example, on the rear of the upper rotating body 3, similar to the engine 11, and supplies hydraulic oil to the control valve 17 through a high-pressure hydraulic line. As described above, the main pump 14 is driven by the engine 11. The main pump 14 is, for example, a variable displacement hydraulic pump, and as described above, under the control of the controller 30, the tilt angle of the swash plate is adjusted by the regulator 13, thereby adjusting the stroke length of the piston and controlling the discharge flow rate (discharge pressure). The main pump 14 includes, for example, main pumps 14L and 14R, as described below.

[0026] The control valve 17 is a hydraulic control device that is mounted, for example, in the center of the upper rotating body 3 and controls the hydraulic drive system in response to an operator's operation of the control device 26. As described above, the control valve 17 is connected to the main pump 14 via a high-pressure hydraulic line, and selectively supplies hydraulic oil supplied from the main pump 14 to the hydraulic actuators (travel hydraulic motors 1L, 1R, swing hydraulic motor 2A, boom cylinder 7, arm cylinder 8, and bucket cylinder 9) in response to the operating state of the control device 26.

[0027] Specifically, the control valve 17 includes control valves 171 to 176 that control the flow rate and flow direction of the hydraulic oil supplied to each of the hydraulic actuators from the main pump 14. More specifically, the control valve 171 corresponds to the traveling hydraulic motor 1L, the control valve 172 corresponds to the traveling hydraulic motor 1R, and the control valve 173 corresponds to the swing hydraulic motor 2A.

[0028] 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. Furthermore, control valve 175 includes, for example, control valves 175L and 175R as described later, and control valve 176 includes, for example, control valves 176L and 176R as described later. Details of control valves 171 to 176 will be described later.

[0029] The operation system of the shovel 100 according to this embodiment includes a pilot pump 15 and an operation device 26. The operation system of the shovel 100 also includes a shuttle valve 32 as a component related to the machine control function of the controller 30, which will be described later.

[0030] The pilot pump 15 is mounted, for example, on the rear of the upper rotating body 3, and supplies pilot pressure to the operating device 26 via a pilot line. The pilot pump 15 is, for example, a fixed displacement hydraulic pump, and is driven by the engine 11 as described above.

[0031] The operation device 26 is provided near the cockpit of the cabin 10 and is an operation input means for the operator to operate various operating elements (undercarriage 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc.).

[0032] In other words, the operating device 26 is an operation input means by which the operator operates the hydraulic actuators that drive each operating element (i.e., the traveling hydraulic motors 1L, 1R, the swing hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, etc.).

[0033] The operation device 26 is connected to the control valve 17 directly through a pilot line on the secondary side thereof, or indirectly via a shuttle valve 32 (described later) provided in the pilot line on the secondary side. This allows a pilot pressure according to the operation state of the undercarriage 1, the upper rotating body 3, the boom 4, the arm 5, the bucket 6, etc. in the operation device 26 to be input to the control valve 17.

[0034] Therefore, the control valve 17 can drive each hydraulic actuator according to the operating state of the operating device 26. The operating device 26 includes, for example, a lever device that operates the arm 5 (arm cylinder 8). The operating device 26 also includes, for example, lever devices 26A to 26C that operate the boom 4 (boom cylinder 7), the bucket 6 (bucket cylinder 9), and the upper rotating body 3 (swing hydraulic motor 2A) respectively (see FIG. 4). The operating device 26 also includes, for example, lever devices and pedal devices that operate each of the pair of left and right crawlers (travel hydraulic motors 1L, 1R) of the lower traveling body 1.

[0035] The shuttle valve 32 has two inlet ports and one outlet port, and outputs hydraulic oil having a higher pilot pressure of the two pilot pressures input to the two inlet ports to the outlet port. One of the two inlet ports of the shuttle valve 32 is connected to the operating device 26, and the other is connected to the proportional valve 31.

[0036] The outlet port of the shuttle valve 32 is connected through a pilot line to the pilot port of the corresponding control valve in the control valve 17 (see FIG. 4 for details). Therefore, the shuttle valve 32 can apply the higher of the pilot pressure generated by the operating device 26 and the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve.

[0037] In other words, a controller 30 (described later) controls the corresponding control valve and controls the operations of various operating elements by causing the proportional valve 31 to output a pilot pressure higher than the secondary pilot pressure output from the operating device 26, without depending on the operator's operation of the operating device 26. The shuttle valve 32 includes, for example, shuttle valves 32AL, 32AR, 32BL, 32BR, 32CL, and 32CR, as described later.

[0038] The operating device 26 (left operating lever, right operating lever, left travel lever, and right travel lever) may be an electric type that outputs an electric signal, instead of a hydraulic pilot type that outputs a pilot pressure.

[0039] In this case, an electrical signal from the operating device 26 is input to the controller 30, and the controller 30 controls each control valve 171 to 176 in the control valve 17 in accordance with the input electrical signal, thereby realizing the operation of various hydraulic actuators in accordance with the operation content of the operating device 26.

[0040] For example, the control valves 171 to 176 in the control valve 17 may be electromagnetic solenoid spool valves that are driven by commands from the controller 30. Also, for example, a solenoid valve that operates in response to an electric signal from the controller 30 may be disposed between the pilot pump 15 and the pilot port of each of the control valves 171 to 176.

[0041] In this case, when manual operation is performed using the electric operating device 26, the controller 30 controls the solenoid valve using an electrical signal corresponding to the amount of operation (e.g., the amount of lever operation) to increase or decrease the pilot pressure, thereby operating each control valve 171 to 176 in accordance with the operation content of the operating device 26.

[0042] The control system of the excavator 100 according to this embodiment includes a controller 30, a discharge pressure sensor 28, an operating pressure sensor 29, a proportional valve 31, a display device 40, an input device 42, an audio output device 43, a memory device 57, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body inclination sensor S4, a turning state sensor S5, an imaging device S6, a positioning device PS, and a communication device T1.

[0043] The controller 30 (an example of a control device) is provided, for example, in the cabin 10 and controls the driving of the excavator 100. The functions of the controller 30 may be realized by any hardware, software, or a combination thereof. For example, the controller 30 is configured mainly with a microcomputer including a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), a non-volatile auxiliary storage device, various input / output interfaces, etc. The controller 30 realizes various functions by, for example, executing various programs stored in the ROM or non-volatile auxiliary storage device on the CPU.

[0044] For example, the controller 30 sets a target rotation speed based on a work mode or the like that is set in advance by a predetermined operation by an operator or the like, and performs drive control to rotate the engine 11 at a constant speed.

[0045] Furthermore, for example, the controller 30 outputs a control command to the regulator 13 as necessary to change the discharge rate of the main pump 14.

[0046] Furthermore, for example, the controller 30 performs control related to a machine guidance function that guides (provides guidance for) the manual operation of the shovel 100 by the operator via the operation device 26. Furthermore, the controller 30 performs control related to a machine control function that automatically assists the manual operation of the shovel 100 by the operator via the operation device 26.

[0047] That is, the controller 30 includes a machine guidance unit 50 as a functional unit related to the machine guidance function and the machine control function. The controller 30 also includes a soil weight processing unit 60, which will be described later.

[0048] Note that some of the functions of the controller 30 may be realized by another controller (control device). That is, the functions of the controller 30 may be realized in a distributed manner by a plurality of controllers. For example, the machine guidance function and the machine control function may be realized by a dedicated controller (control device).

[0049] The discharge pressure sensor 28 detects the discharge pressure of the main pump 14. A detection signal corresponding to the discharge pressure detected by the discharge pressure sensor 28 is input to the controller 30. The discharge pressure sensor 28 includes, for example, discharge pressure sensors 28L and 28R, as described below.

[0050] As described above, the operating pressure sensor 29 detects the secondary pilot pressure of the operating device 26, i.e., the pilot pressure corresponding to the operating state (e.g., the operating content such as the operating direction and the operating amount) of each operating element (i.e., the hydraulic actuator) in the operating device 26.

[0051] A detection signal of the pilot pressure corresponding to the operating state of the lower traveling structure 1, the upper rotating structure 3, the boom 4, the arm 5, the bucket 6, etc. in the operating device 26 by the operating pressure sensor 29 is taken into the controller 30. The operating pressure sensor 29 includes, for example, operating pressure sensors 29A to 29C, as described later.

[0052] In addition, instead of the operating pressure sensor 29, other sensors capable of detecting the operating state of each operating element in the operating device 26, such as an encoder or potentiometer capable of detecting the operating amount (tilting amount) and tilting direction of the lever devices 26A to 26C, may be provided.

[0053] The proportional valve 31 is provided in a pilot line connecting the pilot pump 15 and the shuttle valve 32, and is configured so that its flow path area (cross-sectional area through which hydraulic oil can flow) can be changed. The proportional valve 31 operates in response to a control command input from the controller 30.

[0054] As a result, even when the operating device 26 (specifically, the lever devices 26A to 26C) is not operated by the operator, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via the proportional valve 31 and the shuttle valve 32. The proportional valve 31 includes, for example, proportional valves 31AL, 31AR, 31BL, 31BR, 31CL, and 31CR, as will be described later.

[0055] The display device 40 is provided in a location that is easily visible to an operator seated in the cabin 10, and displays various information images under the control of the controller 30. The display device 40 may be connected to the controller 30 via an in-vehicle communication network such as a Controller Area Network (CAN), or may be connected to the controller 30 via a one-to-one dedicated line.

[0056] The input device 42 is provided within reach of an operator seated in the cabin 10, accepts various operational inputs from the operator, and outputs signals corresponding to the operational inputs to the controller 30. The input device 42 includes a touch panel mounted on the display of the display device 40 that displays various information images, knob switches provided at the tips of the lever portions of the lever devices 26A to 26C, button switches, levers, toggles, rotary dials, etc. that are provided around the display device 40. A signal corresponding to the content of an operation performed on the input device 42 is taken into the controller 30.

[0057] The audio output device 43 is provided, for example, inside the cabin 10, connected to the controller 30, and outputs audio under the control of the controller 30. The audio output device 43 is, for example, a speaker or a buzzer. The audio output device 43 outputs various types of information by audio in response to an audio output command from the controller 30.

[0058] The storage device 57 is provided, for example, inside the cabin 10, and stores various pieces of information under the control of the controller 30. The storage device 57 is, for example, a non-volatile storage medium such as a semiconductor memory. The storage device 57 may store information output by various devices while the shovel 100 is operating, or may store information obtained via various devices before the shovel 100 starts operating.

[0059] The storage device 57 may store data relating to a target construction plane that is acquired via the communication device T1 or the like, or that is set via the input device 42 or the like. The target construction plane may be set (saved) by the operator of the shovel 100, or may be set by a construction manager or the like.

[0060] The boom angle sensor S1 is attached to the boom 4 and detects the elevation angle of the boom 4 relative to the upper rotating body 3 (hereinafter referred to as "boom angle"), for example, the angle formed by a line connecting the fulcrums at both ends of the boom 4 relative to the rotation plane of the upper rotating body 3 in a side view. The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, a six-axis sensor, an IMU (Inertial Measurement Unit), etc.

[0061] The boom angle sensor S1 may also include a potentiometer using a variable resistor, a stroke sensor that detects the stroke amount of the hydraulic cylinder (boom cylinder 7) that corresponds to the boom angle, etc. The same applies to the arm angle sensor S2 and bucket angle sensor S3 below. A detection signal corresponding to the boom angle from the boom angle sensor S1 is input to the controller 30.

[0062] The arm angle sensor S2 is attached to the arm 5 and detects the rotation angle of the arm 5 relative to the boom 4 (hereinafter referred to as the "arm angle"), for example, the angle formed by a line connecting the fulcrums at both ends of the arm 5 with a line connecting the fulcrums at both ends of the boom 4 in a side view. A detection signal corresponding to the arm angle detected by the arm angle sensor S2 is input to the controller 30.

[0063] The bucket angle sensor S3 is attached to the bucket 6 and detects the rotation angle of the bucket 6 relative to the arm 5 (hereinafter referred to as the "bucket angle"), for example, the angle formed by a line connecting the fulcrum of the bucket 6 and the tip (cutting edge) with respect to a line connecting the fulcrums at both ends of the arm 5 in a side view. A detection signal corresponding to the bucket angle by the bucket angle sensor S3 is input to the controller 30.

[0064] The machine body inclination sensor S4 detects the inclination state of the machine body (the upper rotating body 3 or the lower running body 1) relative to the horizontal plane. The machine body inclination sensor S4 is attached to, for example, the upper rotating body 3, and detects the inclination angles of the excavator 100 (i.e., the upper rotating body 3) around two axes in the front-to-rear and left-to-right directions (hereinafter referred to as the "front-to-rear inclination angle" and the "left-to-right inclination angle").

[0065] The vehicle tilt sensor S4 may include, for example, a rotary encoder, an acceleration sensor, a six-axis sensor, an IMU, etc. A detection signal corresponding to the tilt angle (forward / backward tilt angle and left / right tilt angle) detected by the vehicle tilt sensor S4 is input to the controller 30.

[0066] The rotation state sensor S5 outputs detection information related to the rotation state of the upper rotating body 3. The rotation state sensor S5 detects, for example, the rotation angular velocity and rotation angle of the upper rotating body 3. The rotation state sensor S5 may include, for example, a gyro sensor, a resolver, a rotary encoder, etc. The detection signals corresponding to the rotation angle and rotation angular velocity of the upper rotating body 3 detected by the rotation state sensor S5 are input to the controller 30.

[0067] The imaging device S6 as a spatial recognition device captures images of the periphery of the shovel 100. The imaging device S6 includes a camera S6F that captures images in front of the shovel 100, a camera S6L that captures images to the left of the shovel 100, a camera S6R that captures images to the right of the shovel 100, and a camera S6B that captures images behind the shovel 100. The imaging device S6 may include an attachment camera attached to an attachment.

[0068] Camera S6F is attached, for example, to the ceiling of cabin 10, i.e., inside cabin 10. Camera S6F may also be attached to the exterior of cabin 10, such as the roof of cabin 10 or the side of boom 4. Camera S6L is attached to the left end of the upper surface of the upper rotating body 3, camera S6R is attached to the right end of the upper surface of the upper rotating body 3, and camera S6B is attached to the rear end of the upper surface of the upper rotating body 3.

[0069] The imaging device S6 (cameras S6F, S6B, S6L, and S6R) is, for example, a monocular wide-angle camera having a very wide angle of view. The imaging device S6 may also be a stereo camera or a distance imaging camera. Images captured by the imaging device S6 are input to the controller 30 via the display device 40.

[0070] The imaging device S6 as a spatial recognition device may function as an object detection device. In this case, the imaging device S6 may detect objects present around the shovel 100. Objects to be detected may include, for example, people (helmets, safety vests, etc.), animals, vehicles (dump trucks, etc.), construction machinery, buildings, holes, etc. Furthermore, the imaging device S6 may calculate the distance from the imaging device S6 or the shovel 100 to the recognized object. The imaging device S6 as an object detection device may include, for example, a stereo camera, a distance image sensor, etc. The imaging device S6 as a spatial recognition device may be configured to be able to identify at least one of the type, position, shape, etc. of objects around the shovel.

[0071] The spatial recognition device is, for example, a monocular camera having an imaging element such as a CCD or CMOS, and outputs the captured image to the display device 40. The spatial recognition device may also be configured to calculate the distance from the spatial recognition device or the shovel 100 to the recognized object. In addition to the imaging device S6, other object detection devices such as an ultrasonic sensor, millimeter wave radar, LIDAR, or infrared sensor may also be provided as the spatial recognition device.

[0072] When a millimeter wave radar, an ultrasonic sensor, a laser radar, or the like is used as the spatial recognition device, multiple signals (laser light, etc.) may be emitted to an object and the reflected signals may be received to detect the distance and direction of the object from the reflected signals. When an object detection device is provided, the imaging device S6 may be omitted.

[0073] The imaging device S6 may be directly connected to the controller 30 so as to be able to communicate with it.

[0074] A boom rod pressure sensor S7R and a boom bottom pressure sensor S7B are attached to the boom cylinder 7. An arm rod pressure sensor S8R and an arm bottom pressure sensor S8B are attached to the arm cylinder 8.

[0075] A bucket rod pressure sensor S9R and a bucket bottom pressure sensor S9B are attached to the bucket cylinder 9. The boom rod pressure sensor S7R, the boom bottom pressure sensor S7B, the arm rod pressure sensor S8R, the arm bottom pressure sensor S8B, the bucket rod pressure sensor S9R, and the bucket bottom pressure sensor S9B are also collectively referred to as the "cylinder pressure sensors."

[0076] The boom rod pressure sensor S7R detects the pressure in the rod side oil chamber of the boom cylinder 7 (hereinafter referred to as the "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 the "boom bottom pressure").

[0077] 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").

[0078] The bucket rod pressure sensor S9R detects the pressure in the rod-side oil chamber of the bucket cylinder 9 (hereinafter referred to as the "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 the "bucket bottom pressure").

[0079] The positioning device PS measures the position and orientation 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, and a detection signal corresponding to the position and orientation of the upper rotating body 3 is input into the controller 30. Furthermore, among the functions of the positioning device PS, the function of detecting the orientation of the upper rotating body 3 may be substituted by a direction sensor attached to the upper rotating body 3.

[0080] The communication device T1 communicates with external devices such as the support device 200 of the shovel 100 through a predetermined network including a mobile communication network with a base station as its terminal, a satellite communication network, the Internet network, etc. The support device 200 of the shovel 100 may be used, for example, by a manager who manages the work site where the shovel 100 performs work, or may be carried by the operator of the shovel 100. The support device 200 may also be, for example, a smartphone, a tablet-type terminal device, etc.

[0081] 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), and 5G (5th Generation), or a satellite communication module for connecting to a satellite communication network.

[0082] The machine guidance unit 50, for example, executes control of the excavator 100 related to the machine guidance function. The machine guidance unit 50 conveys work information, such as the distance between the target construction surface and the tip of the attachment, specifically, the working portion of the end attachment, to the operator via the display device 40, the audio output device 43, etc.

[0083] Data relating to the target construction surface is stored in advance in the storage device 57, for example, as described above. The data relating to the target construction surface is expressed, for example, in a reference coordinate system. The reference coordinate system is, for example, the World Geodetic System. The World Geodetic System is a three-dimensional orthogonal XYZ coordinate system with its origin at the center of gravity of the Earth, its X axis pointing in the direction of the intersection of the Greenwich meridian and the equator, its Y axis pointing in the direction of 90 degrees east longitude, and its Z axis pointing in the direction of the North Pole.

[0084] The operator may set an arbitrary point on the construction site as a reference point and, via the input device 42, set a target trajectory for the area to be excavated based on a relative positional relationship with the reference point. The set target trajectory is a target trajectory for excavation set below the ground surface. The working part of the bucket 6 is, for example, the toe of the bucket 6, the back of the bucket 6, etc. Here, the target trajectory is calculated based on the shape of the ground surface of the area to be excavated before excavation or the shape of the temporarily placed mound (shape of the excavation target). The shape of the excavation target before excavation is acquired by a spatial recognition device. Alternatively, the shape of the excavation target before excavation may be acquired based on the trajectory of the toe of the bucket 6 during the previous excavation. Then, the controller 30 generates a target trajectory for the current excavation based on the acquired shape of the excavation target before excavation and the excavation operation setup. In this way, the controller 30 updates the target trajectory for the excavation every time a loading operation is performed. Alternatively, the controller 30 may generate a target trajectory to achieve a target weight.

[0085] Furthermore, if a grapple or a lifting magnet is used as the end attachment instead of the bucket 6, the tip of the grapple or the bottom surface of the lifting magnet corresponds to the working part. The machine guidance unit 50 notifies the operator of work information via the display device 40, the audio output device 43, etc., and guides the operator in operating the excavator 100 via the operating device 26.

[0086] Furthermore, the machine guidance unit 50 executes, for example, control of the excavator 100 related to a machine control function. For example, when an operator is manually performing an excavation operation, the machine guidance unit 50 may automatically operate at least one of the boom 4, the arm 5, and the bucket 6 so that the tip position of the bucket 6 coincides with a target trajectory.

[0087] The machine guidance unit 50 acquires information from a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body tilt sensor S4, a turning state sensor S5, an imaging device S6, a positioning device PS, a communication device T1, an input device 42, and the like.

[0088] Then, for example, based on the acquired information, the machine guidance unit 50 automatically controls the operation of the attachment so that the tip of the attachment (specifically, the working parts such as the tip and back of the bucket 6) coincides with the target trajectory.

[0089] The machine guidance unit 50 includes, as detailed functional configurations related to the machine guidance function and the machine control function, a position calculation unit 51, a distance calculation unit 52, an information transmission unit 53, an automatic control unit 54, a turning angle calculation unit 55, and a relative angle calculation unit 56.

[0090] The position calculation unit 51 calculates the position of a predetermined positioning target. For example, the position calculation unit 51 calculates the coordinate point in a reference coordinate system of the tip of the attachment, specifically, the working part such as the tip or back of the bucket 6. Specifically, the position calculation unit 51 calculates the coordinate point of the working part of the bucket 6 from the respective elevation and depression angles of the boom 4, arm 5, and bucket 6 (boom angle, arm angle, and bucket angle).

[0091] Distance calculation unit 52 calculates the distance between two positioning targets. For example, distance calculation unit 52 calculates the distance between the tip of the attachment, specifically, a working part such as the tip or back of bucket 6, and the target trajectory. Distance calculation unit 52 may also calculate the angle (relative angle) between the back of bucket 6 as a working part and the target trajectory.

[0092] The information transmission unit 53 transmits (notifies) various pieces of information to the operator of the shovel 100 through predetermined notification means such as the display device 40 or the audio output device 43. The information transmission unit 53 notifies the operator of the shovel 100 of the magnitude (degree) of the various distances calculated by the distance calculation unit 52.

[0093] For example, the distance (magnitude) between the tip of the bucket 6 and the target trajectory is communicated to the operator using at least one of visual information from the display device 40 and auditory information from the audio output device 43. Furthermore, the information transmission unit 53 may communicate to the operator the relative angle (magnitude) between the back surface of the bucket 6 as the working part and the target trajectory using at least one of visual information from the display device 40 and auditory information from the audio output device 43.

[0094] Furthermore, the information transmission unit 53 may cause the display device 40 to display, as work information, the distance between the tip of the attachment, specifically the working portion of the bucket 6, and the target trajectory, the magnitude of the relative angle between the back surface of the bucket 6 and the target trajectory, etc. Under the control of the controller 30, the display device 40 displays, for example, image data received from the imaging device S6 and the work information received from the information transmission unit 53. The information transmission unit 53 may communicate the vertical distance to the operator using, for example, an image of an analog meter or a bar graph indicator.

[0095] The automatic control unit 54 automatically assists the operator in manually operating the shovel 100 through the operating device 26 by automatically operating the actuator.

[0096] Specifically, as will be described later, the automatic control unit 54 can individually and automatically adjust the pilot pressures acting on the control valves (specifically, the control valves 173, 175L, 175R, and 174) corresponding to the plurality of hydraulic actuators (specifically, the swing hydraulic motor 2A, the boom cylinder 7, and the bucket cylinder 9). This allows the automatic control unit 54 to automatically operate each of the hydraulic actuators.

[0097] Control related to the machine control function by the automatic control unit 54 may be executed, for example, when a predetermined switch included in the input device 42 is pressed. The predetermined switch may be, for example, a machine control switch (hereinafter referred to as an "MC (Machine Control) switch"), and may be arranged as a knob switch at the tip of a portion of the operating device 26 (for example, a lever device corresponding to the operation of the arm 5) that is held by the operator. The following description will be given on the assumption that the machine control function is enabled when the MC switch is pressed.

[0098] For example, when an MC switch or the like is pressed, the automatic control unit 54 automatically extends and retracts at least one of the boom cylinder 7 and the bucket cylinder 9 in accordance with the operation of the arm cylinder 8 to assist in excavation work or shaping work.

[0099] Specifically, when the operator manually closes the arm 5 (hereinafter referred to as "arm closing operation"), the automatic control unit 54 automatically extends and retracts at least one of the boom cylinder 7 and the bucket cylinder 9 so that the target trajectory coincides with the position of a work part such as the tip or back of the bucket 6. In this case, the operator can close the arm 5 while aligning the tip of the bucket 6 with the target construction surface, for example, simply by performing an arm closing operation on a lever device corresponding to the operation of the arm 5.

[0100] In addition, when an MC switch or the like is pressed, the automatic control unit 54 may automatically rotate the swing hydraulic motor 2A (an example of an actuator) to orient the upper swing body 3 directly toward the area to be excavated for which the target trajectory is set.

[0101] Hereinafter, the control by the controller 30 (automatic control unit 54) to make the upper rotating body 3 face the area to be excavated will be referred to as "facing control." This allows an operator or the like to face the upper rotating body 3 face-to-face with the area to be excavated simply by pressing a predetermined switch, or, with the switch pressed, by operating a lever device 26C (described below) corresponding to a swing operation. In addition, the operator can face the upper rotating body 3 face-to-face with the area to be excavated and start the machine control function related to the excavation work and the like in the area to be excavated simply by pressing an MC switch.

[0102] Specifically, when a predetermined switch such as an MC switch is pressed and the lever device 26C corresponding to the rotation operation is operated, it is determined whether the lever device 26C has been operated in a direction that faces the upper rotating body 3 directly toward the area to be excavated.

[0103] For example, when the lever device 26C is operated in a direction in which the toe of the bucket 6 moves away from the area to be excavated, the automatic control unit 54 does not execute the facing control. On the other hand, when the swing operation lever is operated in a direction in which the toe of the bucket 6 moves closer to the area to be excavated, the automatic control unit 54 executes the facing control.

[0104] As a result, the automatic control unit 54 can operate the swing hydraulic motor 2A so as to reduce the distance (or the swing angle) between the toe of the bucket 6 and the area to be excavated. Thereafter, when the difference becomes equal to or less than a predetermined value or becomes zero, the automatic control unit 54 stops the swing hydraulic motor 2A.

[0105] Furthermore, the automatic control unit 54 may set a swing angle at which the difference is equal to or less than a predetermined value or zero as a target angle, and control the operation of the swing hydraulic motor 2A so that the angle difference between the target angle and the current swing angle (specifically, the detected value based on the detection signal of the swing state sensor S5) becomes zero. In this case, the swing angle is, for example, the angle of the front-rear axis of the upper swing body 3 with respect to the reference direction.

[0106] As described above, when a swing electric motor is mounted on the excavator 100 instead of the swing hydraulic motor 2A, the automatic control unit 54 performs facing control with the swing electric motor (an example of an actuator) as the control target.

[0107] The slewing angle calculation unit 55 calculates the slewing angle of the upper rotating body 3. This allows the controller 30 to identify the current orientation of the upper rotating body 3. The slewing angle calculation unit 55 calculates the angle of the longitudinal axis of the upper rotating body 3 relative to a reference direction as the slewing angle based on, for example, an output signal of a GNSS compass included in the positioning device PS.

[0108] Furthermore, the turning angle calculation unit 55 may calculate the turning angle based on the detection signal of the turning state sensor S5. Furthermore, when a reference point is set at the construction site, the turning angle calculation unit 55 may use the direction of the reference point as viewed from the turning axis as the reference direction.

[0109] The rotation angle indicates the direction in which the attachment operating surface extends relative to the reference direction. The attachment operating surface is a virtual plane that cuts through the excavation area or coincides with the target trajectory, and is positioned so that it is perpendicular to the rotation plane. The rotation plane is, for example, a virtual plane that includes the bottom surface of the rotating frame that is perpendicular to the rotation axis. The controller 30 (machine guidance unit 50) determines that the upper rotating body 3 is directly facing the target construction surface, for example, when it determines that the attachment operating surface includes the normal to the target construction surface.

[0110] The relative angle calculation unit 56 calculates the swing angle (relative angle) required to make the upper swing body 3 face the excavation target area. The relative angle is, for example, the relative angle formed between the direction of the front-rear axis of the upper swing body 3 when the upper swing body 3 is faced directly with the excavation target area and the current direction of the front-rear axis of the upper swing body 3. The relative angle calculation unit 56 calculates the relative angle based on, for example, data related to the excavation target area stored in the storage device 57 and the swing angle calculated by the swing angle calculation unit 55.

[0111] When a lever device 26C corresponding to a rotation operation is operated while a predetermined switch such as an MC switch is pressed, the automatic control unit 54 determines whether the upper rotating body 3 has been rotated in a direction that faces the area to be excavated.

[0112] When the automatic control unit 54 determines that the upper rotating body 3 has been operated to rotate in a direction that makes it face the excavation target area, it sets the relative angle calculated by the relative angle calculation unit 56 as the target angle. Then, when the change in the rotation angle after the lever device 26C is operated reaches the target angle, the automatic control unit 54 may determine that the upper rotating body 3 faces the excavation target area, and may stop the movement of the swing hydraulic motor 2A.

[0113] As a result, the automatic control unit 54 can make the upper revolving body 3 face the excavation target area on the premise of the configuration shown in Fig. 2. Although the above-mentioned example of facing control has shown an example of facing control for the excavation target area, the present invention is not limited to this.

[0114] For example, even in the scooping operation when loading temporary soil and sand onto a dump truck, the swing operation may be controlled so that the attachment faces the dump truck. The excavation trajectory is changed each time a scooping operation is performed. Therefore, after discharging soil and sand onto the dump truck, the attachment is controlled to face the newly changed excavation trajectory.

[0115] The swing hydraulic motor 2A has a first port 2A1 and a second port 2A2. The hydraulic sensor 21 detects the pressure of the hydraulic oil at the first port 2A1 of the swing hydraulic motor 2A. The hydraulic sensor 22 detects the pressure of the hydraulic oil at the second port 2A2 of the swing hydraulic motor 2A. Detection signals corresponding to the discharge pressures detected by the hydraulic sensors 21 and 22 are input to the controller 30.

[0116] Furthermore, the first port 2A1 is connected to a hydraulic oil tank via a relief valve 23. The relief valve 23 opens when the pressure on the first port 2A1 side reaches a predetermined relief pressure, and discharges the hydraulic oil on the first port 2A1 side to the hydraulic oil tank. Similarly, the second port 2A2 is connected to a hydraulic oil tank via a relief valve 24. The relief valve 24 opens when the pressure on the second port 2A2 side reaches a predetermined relief pressure, and discharges the hydraulic oil on the second port 2A2 side to the hydraulic oil tank. Furthermore, it is not necessary to perform facing control using the machine guidance function or the machine control function. Furthermore, the facing operation and excavation operation may be performed manually by the operator.

[0117] Next, the hydraulic system of the excavator 100 according to this embodiment will be described with reference to FIG.

[0118] FIG. 3 is a diagram that schematically shows an example of the configuration of a hydraulic system of the excavator 100 according to this embodiment.

[0119] In FIG. 3, the mechanical power system, hydraulic oil lines, pilot lines, and electrical control system are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively, as in FIG. 2 and other figures.

[0120] The hydraulic system realized by the hydraulic circuit circulates hydraulic oil from each of main pumps 14L, 14R driven by engine 11 through center bypass oil passages C1L, C1R and parallel oil passages C2L, C2R to a hydraulic oil tank.

[0121] The center bypass oil passage C1L starts from the main pump 14L, passes through control valves 171, 173, 175L, and 176L arranged in the control valve 17 in this order, and reaches the hydraulic oil tank.

[0122] The center bypass oil passage C1R starts from the main pump 14R, passes through the control valves 172, 174, 175R, and 176R arranged in the control valve 17 in this order, and reaches the hydraulic oil tank.

[0123] The control valve 171 is a spool valve that supplies hydraulic oil discharged from the main pump 14L to the traveling hydraulic motor 1L and discharges hydraulic oil discharged from the traveling hydraulic motor 1L to a hydraulic oil tank.

[0124] The control valve 172 is a spool valve that supplies hydraulic oil discharged from the main pump 14R to the traveling hydraulic motor 1R and discharges hydraulic oil discharged from the traveling hydraulic motor 1R to a hydraulic oil tank.

[0125] The control valve 173 is a spool valve that supplies the hydraulic oil discharged from the main pump 14L to the swing hydraulic motor 2A and discharges the hydraulic oil discharged from the swing hydraulic motor 2A to a hydraulic oil tank.

[0126] The control valve 174 is a spool valve that supplies the hydraulic oil discharged from the main pump 14R to the bucket cylinder 9 and also discharges the hydraulic oil in the bucket cylinder 9 to a hydraulic oil tank.

[0127] The control valves 175L and 175R are spool valves that supply the hydraulic oil discharged from the main pumps 14L and 14R to the boom cylinder 7 and discharge the hydraulic oil in the boom cylinder 7 to a hydraulic oil tank, respectively.

[0128] The control valves 176L, 176R supply the hydraulic oil discharged by the main pumps 14L, 14R to the arm cylinder 8, and also discharge the hydraulic oil in the arm cylinder 8 to a hydraulic oil tank.

[0129] The control valves 171, 172, 173, 174, 175L, 175R, 176L, and 176R adjust the flow rate of hydraulic oil supplied to or discharged from the hydraulic actuators and switch the flow direction, depending on the pilot pressure acting on the pilot port.

[0130] The parallel oil passage C2L supplies the hydraulic oil of the main pump 14L to the control valves 171, 173, 175L, and 176L in parallel with the center bypass oil passage C1L.

[0131] Specifically, the parallel oil passage C2L branches off from the center bypass oil passage C1L upstream of the control valve 171 and is configured to be able to supply hydraulic oil for the main pump 14L in parallel to each of the control valves 171, 173, 175L, and 176R. This allows the parallel oil passage C2L to supply hydraulic oil to a downstream control valve when the flow of hydraulic oil through the center bypass oil passage C1L is restricted or blocked by any of the control valves 171, 173, and 175L.

[0132] The parallel oil passage C2R supplies hydraulic oil for the main pump 14R to the control valves 172, 174, 175R, and 176R in parallel with the center bypass oil passage C1R. Specifically, the parallel oil passage C2R branches off from the center bypass oil passage C1R upstream of the control valve 172 and is configured to be able to supply hydraulic oil for the main pump 14R in parallel to each of the control valves 172, 174, 175R, and 176R. When the flow of hydraulic oil through the center bypass oil passage C1R is restricted or blocked by any of the control valves 172, 174, and 175R, the parallel oil passage C2R can supply hydraulic oil to a control valve further downstream.

[0133] The regulators 13L and 13R, under the control of the controller 30, adjust the tilt angles of the swash plates of the main pumps 14L and 14R, thereby adjusting the discharge amounts of the main pumps 14L and 14R.

[0134] The discharge pressure sensor 28L detects the discharge pressure of the main pump 14L, and a detection signal corresponding to the detected discharge pressure is input to the controller 30. The same applies to the discharge pressure sensor 28R. This allows the controller 30 to control the regulators 13L, 13R in accordance with the discharge pressures of the main pumps 14L, 14R.

[0135] The center bypass oil passages C1L, C1R are provided with throttles 18L, 18R between the hydraulic oil tank and the most downstream control valves 176L, 176R, respectively. As a result, the flow of hydraulic oil discharged by the main pumps 14L, 14R is restricted by the throttles 18L, 18R. The throttles 18L, 18R then generate control pressure for controlling the regulators 13L, 13R.

[0136] The control pressure sensors 19L and 19R detect the control pressures, and the controller 30 receives detection signals corresponding to the detected control pressures.

[0137] The controller 30 may control the regulators 13L, 13R in accordance with the discharge pressures of the main pumps 14L, 14R detected by the discharge pressure sensors 28L, 28R to adjust the discharge rates of the main pumps 14L, 14R. For example, the controller 30 may control the regulator 13L in accordance with an increase in the discharge pressure of the main pump 14L to adjust the swash plate tilt angle of the main pump 14L to reduce the discharge rate. The same applies to the regulator 13R. In this way, the controller 30 can perform total horsepower control of the main pumps 14L, 14R so that the absorption horsepower of the main pumps 14L, 14R, which is expressed as the product of the discharge pressure and the discharge rate, does not exceed the output horsepower of the engine 11.

[0138] Furthermore, the controller 30 may adjust the discharge rates of the main pumps 14L, 14R by controlling the regulators 13L, 13R in accordance with the control pressures detected by the control pressure sensors 19L, 19R. For example, the controller 30 decreases the discharge rates of the main pumps 14L, 14R as the control pressure increases, and increases the discharge rates of the main pumps 14L, 14R as the control pressure decreases.

[0139] Specifically, when the excavator 100 is in a standby state (the state shown in FIG. 3 ) in which none of the hydraulic actuators are operated, the hydraulic oil discharged from the main pumps 14L, 14R passes through the center bypass oil passages C1L, C1R and reaches the throttles 18L, 18R. The flow of the hydraulic oil discharged from the main pumps 14L, 14R increases the control pressure generated upstream of the throttles 18L, 18R. As a result, the controller 30 reduces the discharge rate of the main pumps 14L, 14R to the allowable minimum discharge rate, thereby suppressing pressure loss (pumping loss) when the discharged hydraulic oil passes through the center bypass oil passages C1L, C1R.

[0140] On the other hand, when any of the hydraulic actuators is operated through the operating device 26, the hydraulic oil discharged from the main pumps 14L, 14R flows into the hydraulic actuator to be operated via the control valve corresponding to the hydraulic actuator to be operated.

[0141] The flow of hydraulic oil discharged from the main pumps 14L, 14R reduces or eliminates the amount of hydraulic oil reaching the throttles 18L, 18R, lowering the control pressure generated upstream of the throttles 18L, 18R. As a result, the controller 30 increases the discharge amount of the main pumps 14L, 14R, circulates sufficient hydraulic oil to the hydraulic actuators to be operated, and can reliably drive the hydraulic actuators to be operated.

[0142] Next, with reference to Fig. 4A to Fig. 4D, a configuration for the controller 30 to operate the actuators using the machine control function will be described. Fig. 4A to Fig. 4D are diagrams illustrating portions of the hydraulic system. Specifically, Fig. 4A is a diagram illustrating the hydraulic system portion related to the operation of the arm cylinder 8, and Fig. 4B is a diagram illustrating the hydraulic system portion related to the operation of the boom cylinder 7. Fig. 4C is a diagram illustrating the hydraulic system portion related to the operation of the bucket cylinder 9, and Fig. 4D is a diagram illustrating the hydraulic system portion related to the operation of the swing hydraulic motor 2A.

[0143] 4A to 4D, the hydraulic system includes a proportional valve 31. The proportional valve 31 includes proportional valves 31AL to 31DL and 31AR to 31DR.

[0144] The proportional valve 31 functions as a control valve for machine control. The proportional valve 31 is disposed in a pipe connecting the pilot pump 15 and the pilot port of the corresponding control valve in the control valve unit 17, and is configured to be able to change the flow path area of ​​the pipe. In this embodiment, the proportional valve 31 operates in response to a control command output by the controller 30.

[0145] Therefore, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17 via the proportional valve 31, regardless of the operation of the operating device 26 by the operator. Then, the controller 30 can apply the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve.

[0146] With this configuration, the controller 30 can operate the hydraulic actuator corresponding to a specific operating device 26 even when no operation is being performed on that specific operating device 26. Furthermore, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to that specific operating device 26 even when an operation is being performed on that specific operating device 26.

[0147] 4A, the left operating lever 26L is used to operate the arm 5. Specifically, the left operating lever 26L uses hydraulic oil discharged from the pilot pump 15 to apply pilot pressure to the pilot port of the control valve 176 in accordance with operation in the forward / backward direction.

[0148] More specifically, when the left operating lever 26L is operated in the arm closing direction (rearward), a pilot pressure according to the amount of operation is applied to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R. When the left operating lever 26L is operated in the arm opening direction (forward), a pilot pressure according to the amount of operation is applied to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R.

[0149] The left operating lever 26L is provided with a switch NS. In this embodiment, the switch NS is a push button switch provided at the tip of the left operating lever 26L. The operator can operate the left operating lever 26L while pressing the switch NS. The switch NS may be provided on the right operating lever 26R or at another position within the cabin 10.

[0150] The operation sensor 29LA detects the operation of the left operation lever 26L by the operator in the forward and backward directions, and outputs the detected value to the controller 30.

[0151] The proportional valve 31AL operates in response to a control command (current command) output by the controller 30. The proportional valve 31AL adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL.

[0152] The proportional valve 31AR operates in response to a control command (current command) output by the controller 30. It adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR. The proportional valve 31AR can adjust the pilot pressure so that the control valves 176L and 176R can be stopped at any valve position. Similarly, the proportional valve 31AR can adjust the pilot pressure so that the control valves 176L and 176R can be stopped at any valve position.

[0153] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL in response to the arm closing operation by the operator. Furthermore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL, regardless of the arm closing operation by the operator. In other words, the controller 30 can close the arm 5 in response to the arm closing operation by the operator or regardless of the arm closing operation by the operator.

[0154] Furthermore, in response to an arm-opening operation by the operator, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR. Furthermore, regardless of an arm-opening operation by the operator, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR. In other words, the controller 30 can open the arm 5 in response to an arm-opening operation by the operator or regardless of an arm-opening operation by the operator.

[0155] Furthermore, with this configuration, even when the operator is performing an arm closing operation, the controller 30 can, as necessary, reduce the pilot pressure acting on the closing side pilot ports of the control valve 176 (the left pilot port of the control valve 176L and the right pilot port of the control valve 176R) to forcibly stop the closing operation of the arm 5. The same applies to the case where the opening operation of the arm 5 is forcibly stopped when the operator is performing an arm opening operation.

[0156] Alternatively, even when the operator is performing an arm closing operation, the controller 30 may control the proportional valve 31AR as necessary to increase the pilot pressure acting on the opening pilot ports of the control valve 176 (the right pilot port of the control valve 176L and the left pilot port of the control valve 176R) that are located opposite the closing pilot port of the control valve 176, thereby forcibly returning the control valve 176 to the neutral position, thereby forcibly stopping the closing operation of the arm 5. The same applies to the case where the opening operation of the arm 5 is forcibly stopped when the operator is performing an arm opening operation.

[0157] 4B to 4D, the same applies to a case where the operation of the boom 4 is forcibly stopped when the operator is performing a boom-raising or boom-lowering operation, a case where the operation of the bucket 6 is forcibly stopped when the operator is performing a bucket-closing or bucket-opening operation, and a case where the swing operation of the upper swing structure 3 is forcibly stopped when the operator is performing a swing operation. The same also applies to a case where the traveling operation of the lower traveling structure 1 is forcibly stopped when the operator is performing a traveling operation.

[0158] 4B, the right operating lever 26R is used to operate the boom 4. Specifically, the right operating lever 26R uses the hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure to the pilot port of the control valve 175 in accordance with the operation in the forward / backward direction.

[0159] More specifically, when the right operating lever 26R is operated in the boom-up direction (rearward), a pilot pressure corresponding to the amount of operation is applied to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. When the right operating lever 26R is operated in the boom-down direction (forward), a pilot pressure corresponding to the amount of operation is applied to the right pilot port of the control valve 175R.

[0160] The operation sensor 29RA detects the operation of the right operation lever 26R in the forward and backward directions by the operator, and outputs the detected value to the controller 30.

[0161] The proportional valve 31BL operates in response to a control command (current command) output by the controller 30. The proportional valve 31BL adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31BL. The proportional valve 31BR operates in response to a control command (current command) output by the controller 30.

[0162] The proportional valve 31BL adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31BR. The proportional valve 31BL can adjust the pilot pressure so that the control valves 175L and 175R can be stopped at any valve position. The proportional valve 31BR can also adjust the pilot pressure so that the control valve 175R can be stopped at any valve position.

[0163] With this configuration, in response to a boom-raising operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31BL. Furthermore, regardless of a boom-raising operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31BL. In other words, the controller 30 can raise the boom 4 in response to a boom-raising operation by the operator or regardless of a boom-raising operation by the operator.

[0164] Furthermore, in response to a boom lowering operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31BR. Furthermore, regardless of a boom lowering operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31BR. In other words, the controller 30 can lower the boom 4 in response to a boom lowering operation by the operator or regardless of a boom lowering operation by the operator.

[0165] 4C, the right operating lever 26R is also used to operate the bucket 6. Specifically, the right operating lever 26R uses hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure corresponding to operation in the left or right direction to the pilot port of the control valve 174. More specifically, when the right operating lever 26R is operated in the bucket closing direction (leftward), the right operating lever 26R applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 174. When the right operating lever 26R is operated in the bucket opening direction (rightward), the right operating lever 26R applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 174.

[0166] The operation sensor 29RB detects the operation of the right operation lever 26R in the left and right direction by the operator, and outputs the detected value to the controller 30.

[0167] The proportional valve 31CL operates in response to a control command (current command) output by the controller 30. The proportional valve 31CL adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31CL. The proportional valve 31CR operates in response to a control command (current command) output by the controller 30. The proportional valve 31CR adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31CR.

[0168] The proportional valve 31CL is capable of adjusting the pilot pressure so as to stop the control valve 174 at any valve position. Similarly, the proportional valve 31CR is capable of adjusting the pilot pressure so as to stop the control valve 174 at any valve position.

[0169] With this configuration, in response to the bucket closing operation by the operator, controller 30 can supply the hydraulic oil discharged by pilot pump 15 to the left pilot port of control valve 174 via proportional valve 31CL. Furthermore, regardless of the bucket closing operation by the operator, controller 30 can supply the hydraulic oil discharged by pilot pump 15 to the left pilot port of control valve 174 via proportional valve 31CL. In other words, controller 30 can close bucket 6 in response to the bucket closing operation by the operator or regardless of the bucket closing operation by the operator.

[0170] Furthermore, in response to the bucket opening operation by the operator, controller 30 can supply the hydraulic oil discharged by pilot pump 15 to the right pilot port of control valve 174 via proportional valve 31CR. Furthermore, regardless of the bucket opening operation by the operator, controller 30 can supply the hydraulic oil discharged by pilot pump 15 to the right pilot port of control valve 174 via proportional valve 31CR. In other words, controller 30 can open bucket 6 in response to the bucket opening operation by the operator or regardless of the bucket opening operation by the operator.

[0171] 4D, the left operating lever 26L is also used to operate the swing mechanism 2. Specifically, the left operating lever 26L uses hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure corresponding to operation in the left or right direction to the pilot port of the control valve 173. More specifically, when the left operating lever 26L is operated in the left swing direction (leftward), the left operating lever 26L applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 173. When the left operating lever 26L is operated in the right swing direction (rightward), the left operating lever 26L applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 173.

[0172] The operation sensor 29LB detects the operation of the left operation lever 26L by the operator in the left and right directions, and outputs the detected value to the controller 30.

[0173] The proportional valve 31DL operates in response to a control command (current command) output by the controller 30. The proportional valve 31DL adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31DL.

[0174] The proportional valve 31DR operates in response to a control command (current command) output by the controller 30. It adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31DR. The proportional valve 31DL can adjust the pilot pressure so that the control valve 173 can be stopped at any valve position. Similarly, the proportional valve 31DR can adjust the pilot pressure so that the control valve 173 can be stopped at any valve position.

[0175] With this configuration, in response to a left swing operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31DL. Furthermore, regardless of a left swing operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31DL. In other words, the controller 30 can swing the swing mechanism 2 left in response to a left swing operation by the operator or regardless of a left swing operation by the operator.

[0176] Furthermore, in response to a right turning operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31DR. Furthermore, regardless of a right turning operation by the operator, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31DR. In other words, the controller 30 can rotate the swing mechanism 2 to the right in response to a right turning operation by the operator or regardless of a right turning operation by the operator.

[0177] The excavator 100 may be configured to automatically move the lower traveling structure 1 forward and backward. In this case, the hydraulic system portion related to the operation of the left traveling hydraulic motor 2ML and the hydraulic system portion related to the operation of the right traveling hydraulic motor 2MR may be configured in the same manner as the hydraulic system portion related to the operation of the boom cylinder 7, etc.

[0178] The excavator 100 may also be configured to automatically operate the bucket tilt mechanism. In this case, the hydraulic system portion related to the bucket tilt cylinder that constitutes the bucket tilt mechanism may be configured in the same manner as the hydraulic system portion related to the operation of the boom cylinder 7, etc.

[0179] Furthermore, although an electric control lever has been described as a form of the operation device 26, a hydraulic control lever may be used instead of an electric control lever. In this case, the lever operation amount of the hydraulic control lever may be detected in the form of pressure by a pressure sensor and input to the controller 30. Furthermore, a solenoid valve may be disposed between the operation device 26 as a hydraulic control lever and the pilot port of each control valve.

[0180] The solenoid valves are configured to operate in response to electrical signals from the controller 30. With this configuration, when manual operation is performed using the operating device 26 as a hydraulic control lever, the operating device 26 can move each control valve by increasing or decreasing the pilot pressure in accordance with the amount of lever operation. Each control valve may also be configured as an electromagnetic spool valve. In this case, the electromagnetic spool valve operates in response to an electrical signal from the controller 30 that corresponds to the amount of lever operation of the electric control lever.

[0181] Next, details of the configuration related to the soil weight detection function of the shovel 100 according to this embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram schematically showing an example of components related to the soil weight detection function of the shovel 100 according to this embodiment.

[0182] As described above with reference to FIG. 3, the controller 30 includes the soil weight processing unit 60 as a functional unit related to the function of detecting the weight of the soil excavated by the bucket 6 (soil weight).

[0183] The soil weight processing unit 60 has a weight calculation unit 61 , a maximum load capacity detection unit 62 , a load capacity calculation unit 63 , a remaining load capacity calculation unit 64 , a center of gravity calculation unit 65 , a state determination unit 66 , and a suppression control unit 67 .

[0184] Here, an example of the operation of loading earth and sand (cargo) onto a dump truck by the excavator 100 according to this embodiment will be described.

[0185] First, the shovel 100 controls the attachment at the excavation position to excavate earth and sand with the bucket 6 (excavation operation). Next, the shovel 100 rotates the upper rotating body 3 to move the bucket 6 from the excavation position to the earth-discharging position (swing operation).

[0186] A loading platform of a dump truck is disposed below the soil unloading position. Next, at the soil unloading position, the excavator 100 controls the attachment to unload the soil in the bucket 6, thereby loading the soil in the bucket 6 onto the loading platform of the dump truck (soil unloading operation).

[0187] Next, the excavator 100 rotates the upper rotating body 3 and moves the bucket 6 from the earth-discharging position to the excavating position (rotating operation). By repeating these operations, the excavator 100 loads the excavated earth and sand into the bed of the dump truck.

[0188] The weight calculation unit 61 calculates the weight of the earth and sand (load) in the bucket 6. The weight calculation unit 61 calculates the weight of the earth and sand based on the thrust of the boom cylinder 7.

[0189] For example, the weight calculation unit 61 calculates the weight of the soil based on the thrust of the boom cylinder 7, the distance from the pin connecting the upper rotating body 3 and the boom 4 to the center of gravity of the soil, and the equation for the moment around the pin connecting the upper rotating body 3 and the boom 4.

[0190] The maximum load capacity detection unit 62 detects the maximum load capacity of the dump truck to be loaded with earth and sand. For example, the maximum load capacity detection unit 62 identifies the dump truck to be loaded with earth and sand based on an image captured by the imaging device S6. "Based on an image captured by the imaging device S6" means, for example, using information obtained by performing one or more image processing operations on the image captured by the imaging device S6.

[0191] Next, the maximum load capacity detection unit 62 detects the maximum load capacity of the dump truck based on the image of the identified dump truck. For example, the maximum load capacity detection unit 62 determines the vehicle type (size, etc.) of the dump truck based on the image of the identified dump truck.

[0192] Specifically, for example, the maximum load capacity detection unit 62 may have a table that associates vehicle types with maximum load capacities, and calculates the maximum load capacity of the dump truck based on the vehicle type determined from the image and the table. Note that the maximum load capacity, vehicle type, etc. of the dump truck may be input by the input device 42, and the maximum load capacity detection unit 62 may calculate the maximum load capacity of the dump truck based on the input information from the input device 42.

[0193] The load amount calculation unit 63 calculates the weight of the earth and sand loaded on the dump truck. That is, every time the earth and sand in the bucket 6 is discharged onto the bed of the dump truck, the load amount calculation unit 63 adds the weight of the earth and sand in the bucket 6 calculated by the weight calculation unit 61 to calculate the load amount (total weight), which is the total weight of the earth and sand loaded onto the bed of the dump truck. Note that when the dump truck to be loaded with earth and sand is a new dump truck, the load amount is reset.

[0194] The remaining load calculation unit 64 calculates the remaining load as the difference between the maximum load of the dump truck detected by the maximum load detection unit 62 and the current load calculated by the load calculation unit 63. The remaining load is the remaining weight of earth and sand that can be loaded onto the dump truck.

[0195] The center of gravity calculation unit 65 calculates the center of gravity of the earth and sand (loaded material) in the bucket 6 immediately after the excavation operation is completed (immediately before the swing operation is started). The method for calculating the center of gravity of the earth and sand will be described later.

[0196] The state determination unit 66 acquires information indicating the state of the earth and sand (load) in the bucket 6 immediately after the excavation operation is completed (immediately before the swing operation is started), and determines the state of the earth and sand.

[0197] The state of the soil and sand in the bucket 6 indicates, for example, the shape of the soil and sand loaded in the bucket 6 and the position of the center of gravity (soil gravity center). In other words, the state of the soil and sand in the bucket 6 in this embodiment indicates the likelihood of the soil and sand spilling out of the bucket 6 during a swing operation.

[0198] Furthermore, the information indicating the state of the earth and sand includes the center of gravity of the earth and sand loaded in the bucket 6, image data showing an image of the bucket 6 loaded with earth and sand, and the like.

[0199] For example, the state determination unit 66 may determine that the state of the soil and sand is prone to spillage when the position of the center of gravity of the soil and sand in the bucket 6 satisfies a predetermined condition.

[0200] Specifically, the state determination unit 66 may determine whether the center of gravity of the soil and sand in the bucket 6 calculated by the center of gravity calculation unit 65 is outside a predetermined range centered on the center of gravity G3 of the bucket 6. The center of gravity G3 of the bucket 6 may be stored in advance in the controller 30.

[0201] In this case, the predetermined condition is that the center of gravity of the soil and sand is outside a predetermined range centered on the reference point (center of gravity of the bucket 6). Therefore, if the center of gravity of the soil and sand in the bucket 6 after excavation is outside a predetermined range centered on the reference point, the state determination unit 66 determines that the state of the soil and sand is prone to spilling. Note that in this embodiment, the reference point is the center of gravity of the bucket 6, but this is not limiting. For example, the reference point may be the center of gravity of the soil and sand when the soil and sand in the bucket 6 is in a state where it is unlikely to spill.

[0202] Furthermore, the state determination unit 66 of this embodiment may determine whether or not the soil is prone to spilling based on the position of the center of gravity of the soil in the bucket 6, rather than by comparing it with a reference point. Specifically, for example, the state determination unit 66 may determine whether or not the soil is prone to spilling based on the position of the center of gravity of the soil calculated by the center of gravity calculation unit 65.

[0203] Specifically, the state determination unit 66 may compare the shape of an image of the excavated soil captured by a camera S6F or the like that captures an image in front of the shovel 100 with the shape of a reference image, and determine whether the degree of match between the images is equal to or less than a predetermined threshold. The reference image may be, for example, an image of soil captured by the camera S6F in a state in which the soil in the bucket 6 is unlikely to spill.

[0204] In this case, the predetermined condition is that the degree of match between the image of the soil and sand in the bucket 6 and the reference image is equal to or less than a predetermined threshold. Therefore, when the degree of match between the image of the soil and sand in the bucket 6 after excavation and the reference image is equal to or less than a predetermined threshold, the condition determination unit 66 determines that the state of the soil and sand is prone to spillage.

[0205] In this embodiment, the information indicating the condition of the soil may include, for example, information indicating the characteristics of the soil at the excavation position. The soil information indicating the characteristics of the soil may include, for example, the type of soil, density, and moisture content. In this embodiment, the soil information may be input in advance into the controller 30 by an operator or the like. Furthermore, the reference point for the shape and center of gravity of the reference soil may be changed depending on the type of bucket.

[0206] The condition determination unit 66 of this embodiment may determine the condition of the soil by referring to soil quality information. For example, soil with a relatively low moisture content is expected to be more likely to spill when loaded into the bucket 6 than soil with a high moisture content. Therefore, the condition determination unit 66 may change the predetermined conditions based on the soil quality information.

[0207] In this way, the state determination unit 66 of this embodiment acquires information indicating the state of the soil and sand, and if the state of the soil and sand satisfies a predetermined condition, determines that the state of the soil and sand is prone to spillage.

[0208] When the state determination unit 66 determines that the state of the soil in the bucket 6 is such that it is prone to spillage, the suppression control unit 67 controls the hydraulic actuator to limit the upper limit of the swing angular velocity of the upper swing body 3. In this embodiment, the suppression control unit 67 may control the hydraulic actuator before the swing operation is started. In the following description, the control by the suppression control unit 67 may sometimes be referred to as suppression control. The control by the suppression control unit 67 will be described in detail later.

[0209] In this embodiment, when the state of soil in the bucket 6 is such that it is prone to spilling, the upper limit of the swing angular velocity in the swing operation is limited, so that even if the bucket 6 is fully loaded with soil, for example, it is possible to prevent soil from spilling from the bucket 6. Details of the control by the suppression control unit 67 will be described later.

[0210] In addition, the soil weight processing unit 60 may display on the display device 40 the weight of the soil in the bucket calculated by the weight calculation unit 61, the maximum load capacity of the dump truck detected by the maximum load capacity detection unit 62, the load capacity of the dump truck (total weight of soil loaded on the bed) calculated by the load capacity calculation unit 63, and the remaining load capacity of the dump truck (remaining weight of soil that can be loaded) calculated by the remaining load capacity calculation unit 64.

[0211] Furthermore, the soil weight processing unit 60 may display a warning on the display device 40 when the load amount exceeds the maximum load amount. Furthermore, the soil weight processing unit 60 may display a warning on the display device 40 when the calculated weight of soil in the bucket 6 exceeds the remaining load amount. Note that the warning does not have to be displayed on the display device 40, but may also be output as an audio signal by the audio output device 43. This makes it possible to prevent soil from being loaded in excess of the maximum load amount of the dump truck.

[0212] Next, with reference to FIG. 5, a method for calculating the weight of earth and sand (load) in the bucket 6 in the weight calculation unit 61 of the shovel 100 according to this embodiment will be described using FIG.

[0213] Fig. 6 is a schematic diagram illustrating parameters related to calculation of soil weight. Fig. 6(a) shows the excavator 100, and Fig. 6(b) shows the vicinity of the bucket 6. In the following explanation, it is assumed that a pin P1, the center of gravity G3 of the bucket, and the center of gravity Gs of the soil, which will be described later, are located on a horizontal line L1.

[0214] Here, the pin connecting the upper rotating body 3 and the boom 4 is designated as P1. The pin connecting the upper rotating body 3 and the boom cylinder 7 is designated as P2. The pin connecting the boom 4 and the boom cylinder 7 is designated as P3. The pin connecting the boom 4 and the arm cylinder 8 is designated as P4. The pin connecting the arm 5 and the arm cylinder 8 is designated as P5. The pin connecting the boom 4 and the arm 5 is designated as P6. The pin connecting the arm 5 and the bucket 6 is designated as P7.

[0215] Furthermore, the center of gravity of the boom 4 is defined as G1. The center of gravity of the arm 5 is defined as G2. The center of gravity of the bucket 6 is defined as G3. The center of gravity of the soil (load) loaded in the bucket 6 is defined as Gs. The reference line L2 is defined as a line that passes through pin P7 and is parallel to the opening surface of the bucket 6. Furthermore, the distance between pin P1 and the center of gravity G1 of the boom 4 is defined as D1. The distance between pin P1 and the center of gravity G2 of the arm 5 is defined as D2. The distance between pin P1 and the center of gravity G3 of the bucket 6 is defined as D3. The distance between pin P1 and the center of gravity Gs of the soil is defined as Ds. The distance between pin P1 and the straight line connecting pins P2 and P3 and pin P1 is defined as Dc.

[0216] Furthermore, the force due to the cylinder pressure of the boom cylinder 7 is defined as Fb. Furthermore, of the boom weight (gravity due to the weight of the boom 4), the vertical component perpendicular to the line connecting the pin P1 and the boom center of gravity G1 is defined as W1a. Of the arm weight (gravity due to the weight of the arm 5), the vertical component perpendicular to the line connecting the pin P1 and the arm center of gravity G2 is defined as W2a. The weight of the bucket 6 is defined as W6, and the weight of the soil (load) loaded in the bucket 6 is defined as Ws.

[0217] 6(a), the position of the pin P7 is calculated from the boom angle and the arm angle. That is, the position of the pin P7 can be calculated based on the detection values ​​of the boom angle sensor S1 and the arm angle sensor S2.

[0218] 6(b), the positional relationship between the pin P7 and the bucket center of gravity G3 (angle θ4 between the reference line L2 of the bucket 6 and the line connecting the pin P7 and the bucket center of gravity G3; distance D4 between the pin P7 and the bucket center of gravity G3) is a predetermined value. Also, the positional relationship between the pin P7 and the soil center of gravity Gs (angle θ5 between the reference line L2 of the bucket 6 and the line connecting the pin P7 and the soil center of gravity Gs; distance D5 between the pin P7 and the soil center of gravity Gs) is determined in advance, for example, experimentally and stored in the controller 30. In other words, the soil center of gravity Gs and the bucket center of gravity G3 can be estimated based on the bucket angle sensor S3.

[0219] That is, the center of gravity calculation unit 65 can estimate the center of gravity Gs of the soil based on the detection values ​​of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3.

[0220] Next, the equation for the balance between each moment around the pin P1 and the boom cylinder 7 can be expressed by the following equation (A1).

[0221] WsDs+W1aD1+W2aD2+W3D3=FbDc...(A1) When equation (A1) is expanded in terms of the soil weight Ws, it can be expressed as the following equation (A2).

[0222] Ws=(FbDc-(W1aD1+W2aD2+W3D3)) / Ds...(A2) Here, the force Fb due to the cylinder pressure of the boom cylinder 7 is calculated from the detected value of at least one of the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B. The distance Dc and the vertical component W1a of the boom weight are calculated from the detected value of the boom angle sensor S1. The vertical component W2a of the arm weight and the distance D2 are calculated from the detected values ​​of the boom angle sensor S1 and the arm angle sensor S2, respectively. The distance D1 and the bucket weight W3 (gravity due to the weight of the bucket 6) are known values. Furthermore, by estimating the soil gravity center Gs and the bucket gravity center G3, the distance Ds and the distance D3 can also be estimated.

[0223] Therefore, the weight Ws of the soil can be calculated based on the detected value of the cylinder pressure of the boom cylinder 7 (detected value of the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B), the boom angle (detected value of the boom angle sensor S1), and the arm angle (detected value of the arm angle sensor S2). This allows the weight calculation unit 61 to calculate the weight Ws of the soil based on the center of gravity Gs of the soil estimated by the center of gravity calculation unit 65.

[0224] Whether or not the excavator 100 is in a normal operation can be determined by estimating the posture of the attachment based on the detected value of the pilot pressure of the bucket cylinder 9.

[0225] In the above description, the attitude of the bucket 6 during normal operation is assumed to be such that the opening surface of the bucket 6 is horizontal, and the center of gravity of the soil is estimated and the weight of the soil is calculated, but this is not limited to this. For example, the bucket 6 may be imaged by a camera S6F that images the front, and the attitude of the bucket 6 may be estimated based on that image. Alternatively, the bucket 6 may be imaged by the camera S6F, and if it is determined that the opening surface of the bucket 6 is horizontal based on that image, the center of gravity of the soil may be estimated and the weight of the soil may be calculated.

[0226] Next, the center of gravity of the soil and the shape of the soil in the bucket 6 of this embodiment will be described with reference to Figures 7 and 8. Figure 7 is a diagram for explaining the center of gravity of the soil in the bucket. Figure 7 is also a side view of the bucket 6.

[0227] Fig. 7(A) shows an example of the center of gravity of the soil that is determined by the state determination unit 66 to be in a state where spillage is unlikely. In other words, Fig. 7(A) shows a case where the state of the soil in the bucket 6 does not satisfy a predetermined condition. Figs. 7(B) and (C) show an example of the center of gravity of the soil that is determined by the state determination unit 66 to be in a state where spillage is likely. In other words, Figs. 7(B) and (C) show a case where the state of the soil in the bucket 6 satisfies a predetermined condition.

[0228] 7(A), the center of gravity Gs of the soil and sand DS in the bucket 6 does not satisfy the predetermined condition because it is within a predetermined range centered on the center of gravity G3 of the bucket 6. Therefore, in this case, control by the suppression control unit 67 is not performed.

[0229] In Figure 7(B), the center of gravity Gs1 of the soil and sand DS in the bucket 6 is located forward beyond a predetermined range from the center of gravity G3 of the bucket 6, which means that the soil and sand are likely to spill during a swing operation. Also, in Figure 7(C), the center of gravity Gs2 of the soil and sand DS in the bucket 6 is located above the center of gravity G3 of the bucket 6 beyond a predetermined range, which means that the soil and sand are likely to spill during a swing operation. Therefore, in the cases of Figures 7(B) and (C), control is performed by the suppression control unit 67.

[0230] Fig. 8 is a diagram illustrating the shape of the soil in the bucket. Fig. 8(A) to Fig. 8(C) are examples of images of the soil in the bucket 6 taken by the camera S6F. Fig. 8 also shows the state viewed forward from the upper rotating body 3.

[0231] 8(A) is an image showing the shape of the soil that is unlikely to spill, determined by the state determination unit 66, and the shape of the soil in the image shown in FIG. 8(A) may be a reference shape. In other words, the image of the soil included in image 91 shown in FIG. 8(A) is a reference image used for determination by the state determination unit 66.

[0232] 8(B) and (C) show examples of the shape of soil and sand that is determined to be in a state that is likely to spill by the state determination unit 66. In other words, FIGS. 8(B) and (C) show cases where the state of soil and sand in the bucket 6 satisfies predetermined conditions.

[0233] In the image 91 shown in FIG. 8(A), the height of the highest piled part of the soil and sand DS in the bucket 6 is within a certain range and is located near the center of the bucket 6.

[0234] In contrast, the highest pile of soil and sand DS in the bucket 6 in image 92 shown in Figure 8(B) is biased to the right side of the bucket 6. As such, the image of soil and sand DS in image 91 and the image of soil and sand DS in image 92 have different shapes, so the degree of match is below a predetermined threshold, making it prone to spillage during a swing operation.

[0235] Similarly, the highest pile of soil DS in the bucket 6 in image 93 shown in Figure 8(C) is biased to the left side of the bucket 6. As such, the image of soil DS in image 91 and the image of soil DS in image 93 have different shapes, so the degree of match is below a predetermined threshold, making it prone to spillage during a swing operation. Therefore, in the cases of Figures 8(B) and (C), control is performed by the suppression control unit 67.

[0236] In this embodiment, the image of the soil and sand DS in the bucket 6 is acquired from an image captured by the camera S6F, but this is not limiting. The image of the soil and sand DS in the bucket 6 may be acquired from an image captured by a camera provided inside the arm 5, for example.

[0237] In this embodiment, the image of the soil and sand DS in the bucket 6 may be acquired from an image captured by an imaging device S6 attached to a member outside the shovel 100, such as a pole installed at the work site. Furthermore, the image of the soil and sand DS in the bucket 6 may be acquired from an image captured by an imaging device S6 attached to an aircraft, such as a drone, flying above the work site.

[0238] In this way, when acquiring an image of the soil DS in the bucket 6 from an image captured by the imaging device S6 provided outside the shovel 100, an image of the side of the bucket 6 may be acquired. Furthermore, when an image of the side of the bucket 6 is acquired, the state determination unit 66 may only make a determination based on the shape of the soil in the bucket 6, and does not need to calculate the center of gravity Gs of the soil in the bucket 6.

[0239] In addition, for example, if the state determination unit 66 cannot extract an image of the soil and sand DS in the bucket 6 from the image captured by the imaging device S6, the state determination unit 66 may only make a determination based on the center of gravity Gs of the soil and sand in the bucket 6 calculated by the center of gravity calculation unit 65.

[0240] The state determination unit 66 of this embodiment may perform both a determination based on the center of gravity Gs of the soil of the bucket 6 and a determination based on the shape of the image of the soil DS, or may perform a determination using either one of them. Whether to use both the center of gravity Gs of the soil and the shape of the soil DS in the determination by the state determination unit 66 or either one of them may be set in advance, or may be determined automatically by the controller 30 depending on the environment, weather, etc. of the work site.

[0241] For example, the controller 30 may use only the shape of the image of the soil and sand DS when an image captured by an imaging device S6 attached to the outside of the shovel 100 at the work site can be acquired. Furthermore, the controller 30 may switch to making a determination using the soil and sand center of gravity Gs when the image captured by the imaging device S6 is not clear.

[0242] Next, suppression control by the suppression control unit 67 of this embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram for explaining control by the suppression control unit.

[0243] In FIG. 9, the horizontal axis indicates the tilt of the operating lever that operates the turning mechanism 2, and the vertical axis indicates the turning angular velocity of the upper turning body 3.

[0244] 9 shows the relationship between the tilt (operation amount) of the right operating lever 26R and the rotation angular velocity of the upper rotating body 3 when control is not performed by the suppression control unit 67, and the solid line L13 shows the relationship between the tilt (operation amount) of the left operating lever 26L and the rotation angular velocity of the upper rotating body 3 when control is not performed by the suppression control unit 67. In the following description, the case where control is not performed by the suppression control unit 67 may be referred to as normal times.

[0245] As shown in FIG. 9, the turning angular velocity (absolute value) relative to θmax, which is the maximum value (absolute value) of the tilt of the right operating lever 26R and the left operating lever 26L in normal times, is ωmax [rad / s].

[0246] In this embodiment, when the state determination unit 66 determines that the state of the soil and sand satisfies predetermined conditions, the suppression control unit 67 controls the hydraulic actuator (swing hydraulic motor 2A) so that the swing angular velocity (absolute value) relative to θmax, which is the maximum value (absolute value) of the inclination of the right operating lever 26R and the left operating lever 26L, is slower than usual.

[0247] The dotted line L12 in Figure 9 shows the relationship between the inclination (operation amount) of the right operating lever 26R and the rotation angular velocity of the upper rotating body 3 when the soil and sand conditions meet specified conditions, and the dotted line L14 shows the relationship between the inclination (operation amount) of the left operating lever 26L and the rotation angular velocity of the upper rotating body 3 when the soil and sand conditions meet specified conditions.

[0248] As can be seen from dotted lines L2 and L4, the way in which the turning angular velocity (absolute value) increases in response to changes in the tilt of the right operating lever 26R and the left operating lever 26L becomes gentler than usual after control by the suppression control unit 67. Furthermore, after control by the suppression control unit 67, the maximum value (absolute value) of the turning angular velocity in response to the maximum value (absolute value) of the tilt of the right operating lever 26R and the left operating lever 26L becomes a value (absolute value) ω1 that is smaller than usual.

[0249] Therefore, in this embodiment, the swing operation after control by the suppression control unit 67 is performed at a slower swing angular velocity than normal, resulting in a gentler operation. Therefore, in this embodiment, the soil DS in the bucket 6 can be moved from the excavation position to the discharge position while suppressing spillage of the soil DS in the bucket 6.

[0250] Although the suppression control unit 67 in this embodiment performs control to limit the rotation angular velocity of the upper rotating body 3, the present invention is not limited to this. The suppression control unit 67 may also control the opening and closing of the bucket 6, for example.

[0251] Specifically, when state determination unit 66 determines that the state of sediment in bucket 6 satisfies a predetermined condition, suppression control unit 67 may control the hydraulic actuator to keep the bucket angle constant. Furthermore, when state determination unit 66 determines that the state of sediment in bucket 6 satisfies a predetermined condition, suppression control unit 67 may perform an operation to close bucket 6 until the bucket angle reaches a predetermined angle.

[0252] In this embodiment, by controlling the operation of the bucket 6 in this manner, the soil and sand DS in the bucket 6 can be moved from the excavation position to the discharge position while suppressing spillage of the soil and sand DS in the bucket 6.

[0253] Next, a function of the controller 30 to calculate and display the weight of earth and sand loaded onto the dump truck DT during loading work will be described with reference to Fig. 10. Fig. 10 is a diagram showing an example of a work site where earth and sand are being loaded onto a dump truck by a shovel.

[0254] Specifically, Fig. 10 is a top view of a work site. In Fig. 10, the shovel 100 drawn with a solid line represents the state of the shovel 100 when the excavation operation is completed, the shovel 100 drawn with a dashed line represents the state of the shovel 100 during the combined operation, and the shovel 100 drawn with a dashed line represents the state of the shovel 100 before the soil discharge operation is started. The thick dashed line in Fig. 10 represents the trajectory of a predetermined point on the back surface of the bucket 6.

[0255] In the controller 30, when the excavation operation is completed and the bucket 6 is raised to a predetermined height, the state determination unit 66 determines the state of the soil and sand in the bucket 6. Specifically, the state determination unit 66 determines the likelihood of the soil and sand spilling out of the bucket 6 during swinging. Thereafter, when the bucket 6 is further raised, the controller 30 calculates the weight of the soil and sand in the bucket 6 (soil weight). Specifically, the weight calculation unit 61 of the soil and sand weight processing unit 60 in the controller 30 calculates the soil weight. The weight calculation unit 61 calculates the soil weight based on the output of at least one of the attitude sensor, the cylinder pressure sensor, the operating pressure sensor 29, etc., for example.

[0256] 10, the weight calculation unit 61 calculates the weight of the soil based on the thrust of the boom cylinder 7, the distance from the pin connecting the upper rotating body 3 and the boom 4 to the center of gravity of the soil, and an equation for the moment around the pin connecting the upper rotating body 3 and the boom 4. The attitude sensor is, for example, at least one of a boom angle sensor, an arm angle sensor S2, a bucket angle sensor S3, a machine body inclination sensor S4, and a rotation state sensor S5.

[0257] Furthermore, the controller 30 may determine whether or not the excavation operation has ended based on the output of at least one of the attitude sensor, the cylinder pressure sensor, the operating pressure sensor 29, and the like.

[0258] In this example, when a predetermined point on the back surface of the bucket 6 is at point PT1, the controller 30 determines that the bucket 6 has risen to a predetermined height after the excavation operation is completed, and the state determination unit 66 determines the likelihood of the soil in the bucket 6 spilling. After that, when the controller 30 determines that the bucket 6 has risen to the predetermined height, the weight calculation unit 61 calculates the weight of the soil. In this case, point PT1 is referenced as a judgment point for the soil shape (judgment point for the likelihood of spilling) set above the excavation end point. Furthermore, a weight calculation point is set above point PT1.

[0259] Thereafter, the operator of the shovel 100 performs a combined operation using the operating device 26. In this example, the operator performs a combined operation that includes a right swing operation. Specifically, the operator performs a combined operation that includes at least one of a boom-raising operation and an arm-closing operation and a right swing operation until the posture of the shovel 100 becomes the posture shown by the dashed line, that is, until a predetermined point on the back surface of the bucket 6 reaches point PT2. The weight calculation unit 61 calculates the weight of the soil and sand until the bucket 6 reaches point PT2. At this time, if the state determination unit 66 determines that the soil and sand in the bucket 6 is likely to spill, the controller 30 performs suppression control.

[0260] The combined operation may include operation of the bucket 6. This is to move the bucket 6 to a point PT3 located above the bed of the dump truck DT, which has a height Hd, while preventing the bucket 6 from coming into contact with the bed. In this example, the combined operation performs a boom-raising and swinging operation.

[0261] Basically, the operator performs a combined operation using this suppression control to prevent soil and sand from spilling out of the bucket 6. This is because soil and sand spilling out of the bucket 6 could soil the dump truck DT. Alternatively, this is because soil and sand spilling out of the bucket 6 could soil the paved road.

[0262] Furthermore, when the operator lifts the bucket 6 into the air, for example, the operator may vibrate the bucket 6 by opening and closing the bucket 6 multiple times with the opening of the bucket 6 facing upward, thereby moving the soil and sand concentrated at the front of the bucket 6 to the rear of the bucket 6. This is to prevent the soil and sand from spilling out of the bucket 6 during the boom-raising and swinging operation by moving the soil and sand to the rear of the bucket 6 and leveling the soil and sand inside the bucket 6. In this way, in this embodiment, even if the shape of the soil and sand in the bucket 6 after excavation is such that it is prone to spilling, an accurate weight of the soil and sand can be calculated by using suppression control to calculate the weight of the soil and sand before point PT2 is reached.

[0263] The vibration of the bucket 6 is typically achieved by slightly moving at least one of the boom 4, the arm 5, and the bucket 6. That is, the vibration of the bucket 6 is typically achieved by slightly extending and retracting the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9.

[0264] The operator then performs a combined operation including an arm opening operation and a right swing operation until the posture of the excavator 100 becomes as shown by the dashed line, that is, until a predetermined point on the back of the bucket 6 reaches point PT3 located above the bed of the dump truck DT. The combined operation may include at least one of operating the boom 4 and operating the bucket 6. In this case, point PT3 is referred to as the start point of earth discharge. The weight of earth and sand in the bucket 6 is calculated while the bucket 6 moves from point PT1 to point PT3. It is preferable to calculate the weight of earth and sand while the bucket 6 moves from point PT1 to point PT2.

[0265] Thereafter, the operator starts the earth discharge operation. That is, the earth in the bucket 6 is dropped from inside the bucket 6 onto the bed of the dump truck DT outside the bucket 6. In this example, the operator performs a combined operation including the bucket opening operation. Specifically, the operator performs a combined operation including the bucket opening operation until the earth in the bucket 6 is discharged onto the bed of the dump truck DT.

[0266] Thereafter, when the bucket 6 is positioned on the bed of the dump truck DT, the controller 30 updates the load amount (total weight) which is the total weight of the earth and sand loaded on the bed of the dump truck DT.

[0267] Specifically, when the earth unloading operation is completed, the controller 30 calculates the load amount (total weight), which is the sum of the weight of the earth and sand loaded on the bed of the dump truck DT. More specifically, the load amount calculation unit 63 of the earth and sand weight processing unit 60 in the controller 30 adds the weight of the earth and sand in the bucket 6 calculated by the weight calculation unit 61 to the current load amount (total weight) every time the earth and sand in the bucket 6 is unloaded onto the bed of the dump truck DT, and updates the load amount (total weight).

[0268] In this example, when the earth and sand in the bucket 6 is discharged onto the bed of the dump truck DT, the load amount calculation unit 63 adds the weight of the earth and sand in the bucket 6 to the current load amount (total weight) to update the load amount (total weight). In this way, the load amount (total weight), which is the sum of the weight of the earth and sand loaded onto the bed of the dump truck DT, is updated on the condition that the bucket 6 is positioned on top of the bed of the dump truck DT.

[0269] On the other hand, when the earth and sand in the bucket 6 is discharged to a place other than the bed of the dump truck DT, the load amount calculation unit 63 does not add the weight of the earth and sand in the bucket 6 to the current load amount (total weight).

[0270] Specifically, the load amount calculation unit 63 determines whether or not an earth unloading operation was performed when the bucket 6 was located above the bed of the dump truck DT, based on the image captured by the camera S6F.

[0271] More specifically, the load amount calculation unit 63 recognizes the respective positions of the bed of the dump truck DT and the bucket 6 based on the image captured by the camera S6F, and then determines whether or not an earth unloading operation was performed when the bucket 6 was above the bed of the dump truck DT. The load amount calculation unit 63 may also determine whether or not an earth unloading operation was performed when the bucket 6 was above the bed of the dump truck DT based on the output of another spatial recognition device such as LIDAR.

[0272] Then, if the load amount calculation unit 63 determines that an earth unloading operation was performed when the bucket 6 was above the bed of the dump truck DT, it adds the weight of the soil and sand in the bucket 6 to the current load amount (total weight) and updates the load amount (total weight).

[0273] On the other hand, if the load amount calculation unit 63 determines that the earth unloading operation was performed when the bucket 6 was not above the bed of the dump truck DT, the load amount calculation unit 63 does not add the weight of the earth and sand in the bucket 6 to the current load amount (total weight). This is to prevent, for example, the weight of earth and sand dumped onto the ground by the earth unloading operation during setup work from being added to the load amount (total weight).

[0274] The load amount calculation unit 63 may be configured to reset the load amount when it is determined that the dump truck DT has moved to transport earth and sand. In this example, the load amount calculation unit 63 determines whether or not the dump truck DT has moved (whether or not it has run away) based on an image captured by the camera S6F. The load amount calculation unit 63 may also determine whether or not the dump truck DT has moved based on the output of another spatial recognition device such as a LIDAR.

[0275] With this configuration, the operator of the shovel 100 does not need to perform the cumbersome operation of pressing a reset button to reset the load weight every time the dump truck DT arrives at or leaves the work site (loading position).

[0276] At a work site where loading work is performed, the operator not only uses a shovel to load the dump truck DT, but also, when the dump truck DT is not present, performs transport work to transport the soil to a location where loading is easy.

[0277] This is to complete the loading operation onto the dump truck DT in a short time. Such transport operations also consist of excavation operations and soil discharge operations, but in the case of transport operations, calculation of the load amount (total weight) is not necessary. By using the above-mentioned function, the excavator 100 can accurately calculate the load amount (total weight) when calculation of the load amount (total weight) is necessary.

[0278] In another embodiment, the weight calculation unit 61 may calculate the weight of the soil (soil weight) in the bucket 6 based on an image captured by the camera S6F. In this case, calculation of the soil weight based on the output of at least one of the attitude sensor, the cylinder pressure sensor, the operating pressure sensor 29, etc. may be omitted.

[0279] For example, when it is determined that the excavation operation has ended, the weight calculation unit 61 calculates the volume of the soil in the bucket 6 based on an image of the soil in the bucket 6 captured by the camera S6F. Then, the weight calculation unit 61 derives the weight of the soil (soil weight) by multiplying the calculated volume value by the density of the soil. The soil density may be a value input in advance, or may be a value dynamically calculated based on the output of at least one of the attitude sensor, the cylinder pressure sensor, the operating pressure sensor 29, etc. Furthermore, the weight calculation unit 61 may calculate the weight of the soil in the bucket 6 (soil weight) based on the output of another spatial recognition device such as LIDAR.

[0280] As described above, the excavator 100 of this embodiment includes the lower traveling body 1, the upper rotating body 3 rotatably mounted on the lower traveling body 1, an attachment attached to the upper rotating body 3, the bucket 6 constituting the attachment, and the controller 30 as a control device. The controller 30 is configured to calculate the weight of the object (earth and sand, etc.) transferred from inside the bucket 6 to the bed of the dump truck DT as a transport vehicle, based on the output of the imaging device S6 and the weight of the object (earth and sand, etc.) in the bucket 6.

[0281] The imaging device S6 is an example of a space recognition device. The space recognition device is a device for recognizing the space around the upper rotating body 3, and in this embodiment, is attached to the upper rotating body 3. However, the space recognition device may also be attached to a member outside the excavator 100, such as a pole installed at the work site.

[0282] In addition, the controller 30 may be configured to add the weight of the object (earth and sand, etc.) in the bucket 6 to the weight of the object loaded on the bed of the dump truck DT when an earth unloading operation is performed on the bed of the dump truck DT.

[0283] With this configuration, the controller 30 can prevent the weight of earth and sand in the bucket 6 from being added to the load amount when an earth and sand discharge operation is performed at a position other than on the bed of the dump truck DT. For example, the controller 30 can prevent the weight of earth and sand discharged onto the ground by an earth and sand discharge operation during setup work from being added to the load amount. This is because the controller 30 can accurately distinguish between an earth and sand discharge operation performed during loading work and an earth and sand discharge operation performed during setup work.

[0284] Controller 30 may calculate the weight of the object (soil, sand, etc.) in bucket 6 based on the output of the spatial recognition device, or may calculate the weight of the object (soil, sand, etc.) in bucket 6 based on the output of a sensor other than the spatial recognition device. Controller 30 may also calculate the weight of the object (soil, sand, etc.) in bucket 6 based on the output of two or more sensors including the spatial recognition device.

[0285] For example, the controller 30 may calculate the weight of the object (soil, sand, etc.) in the bucket 6 based on an image captured by the imaging device S6, or may calculate the weight of the object (soil, sand, etc.) in the bucket 6 based on the output of at least one of the attitude sensor, the cylinder pressure sensor, and the operating pressure sensor 29, etc.

[0286] When calculating the weight of the object (soil, sand, etc.) in the bucket 6 based on the output of the spatial recognition device, the controller 30 can calculate the weight of the soil in the bucket 6 (current weight), the weight of the soil loaded onto the dump truck DT (cumulative weight), the maximum load weight of the dump truck DT, and the remaining weight (the difference between the maximum load weight and the cumulative weight) based only on the output of the spatial recognition device.

[0287] The controller 30 may be configured to determine whether or not it is necessary to reset the weight of the earth and sand loaded on the bed of the dump truck DT based on the output of the spatial recognition device. For example, the controller 30 may reset the accumulated weight to zero when it recognizes, based on an image captured by the imaging device S6 serving as the spatial recognition device, that the dump truck DT parked at the loading position has driven away.

[0288] With this configuration, the controller 30 can improve the operability of the shovel 100. This is because the controller 30 can automatically reset the accumulated weight without forcing the operator of the shovel 100 to perform a cumbersome operation such as pressing a reset button to reset the accumulated weight. As a result, this configuration can improve the work efficiency of the operator of the shovel 100.

[0289] In addition, the controller 30 may be configured to add the weight of the soil in the bucket 6 to the weight of the soil loaded on the bed of the dump truck DT when the bucket 6 is positioned on the bed of the dump truck DT.

[0290] Alternatively, the controller 30 may be configured to add the weight of the soil in the bucket 6 to the weight of the soil loaded onto the bed of the dump truck DT when the soil in the bucket 6 falls from the bucket 6 onto the bed of the dump truck DT.

[0291] With these configurations, the controller 30 can prevent the weight of earth and sand dumped onto the ground by the earth dumping operation during setup work from being added to the load amount (total weight), for example.

[0292] The controller 30 may be configured to determine whether the soil in the bucket 6 falls from the bucket 6 onto the bed of the dump truck DT or outside the bed.

[0293] With this configuration, the controller 30 can prevent the weight of the soil that has fallen from the bucket 6 outside the bed of the dump truck DT from being added to the load amount (total weight), and can also appropriately add the weight of the soil that has fallen from the bucket 6 onto the bed of the dump truck DT to the load amount (total weight).

[0294] If the object in the bucket 6 falls outside the loading platform, the controller 30 may be configured to subsequently calculate the weight inside the bucket 6. For example, if the controller 30 determines that the object in the bucket 6 has fallen outside the loading platform, the controller 30 may be configured to recalculate the weight inside the bucket 6 after that determination and before the soil unloading operation. This is because the weight of the soil remaining in the bucket 6 is calculated based on information obtained after the soil has fallen from the bucket 6, rather than information obtained before the soil has fallen from the bucket 6.

[0295] Next, the processing of the soil weight processing unit 60 of this embodiment will be described with reference to Fig. 11. Fig. 11 is a flowchart illustrating the processing of the soil weight processing unit.

[0296] 11 may be executed when the work site of the excavator 100 is a place where suppression of soil spillage is required. In the following description, a work site where suppression of soil spillage is required may be referred to as a place subject to suppression.

[0297] In this embodiment, the controller 30 may determine whether or not the work site is a place to be restricted. Specifically, for example, the controller 30 may determine whether or not the work site is a place to be restricted based on image data captured by the imaging device S6 included in the shovel 100, an imaging device provided outside the shovel 100, or the like.

[0298] Furthermore, the controller 30 may determine whether or not the work site is a location subject to suppression, for example, based on location information indicating the location of the shovel 100 and map information held in an external device.

[0299] Furthermore, in this embodiment, the work site may be set in advance as a location subject to suppression by a manager of the work site, an operator of the shovel 100, or the like. In other words, the shovel 100 may be set in advance to perform control by the suppression control unit 67 at the work site.

[0300] In this embodiment, the soil weight processing unit 60 acquires information indicating the state of the soil in the bucket 6 after the excavation operation is completed, using the state determination unit 66 (step S1101). Specifically, the state determination unit 66 acquires an image of the bucket 6 loaded with soil DS, the center of gravity of the soil in the bucket 6, etc.

[0301] Next, the state determination unit 66 determines whether the state of the soil and sand is prone to spilling or not, based on the information indicating the state of the soil and sand (step S1102). In other words, the state determination unit 66 determines whether the state of the soil and sand satisfies a predetermined condition or not.

[0302] If it is determined in step S1102 that the state of the soil and sand is not prone to spillage, that is, if the state of the soil and sand does not satisfy the predetermined conditions, the soil and sand weight processing section 60 ends the process without performing suppression control.

[0303] In step S1102, if it is determined that the state of the soil and sand is prone to spillage, that is, if the state of the soil and sand satisfies predetermined conditions, the soil and sand weight processing unit 60 performs suppression control using the suppression control unit 67 (step S1103), terminates the processing, and then measures the weight of the soil and sand.

[0304] As described above, in this embodiment, the hydraulic actuator mounted on the upper rotating body 3 is controlled according to the state of soil and sand in the bucket 6, and the change in the swing angular velocity relative to the tilt of the operating lever is made gentle. Also, in this embodiment, the hydraulic actuator mounted on the upper rotating body 3 is controlled to close the bucket 6 at an angle that makes it difficult for soil and sand in the bucket 6 to spill out.

[0305] Therefore, according to this embodiment, spillage of soil and sand at the work site can be suppressed, and therefore, according to this embodiment, the occurrence of work that would be caused by spillage of soil and sand, such as cleaning work of the surrounding environment, can be suppressed, and work efficiency can be improved.

[0306] Furthermore, according to this embodiment, spillage of earth and sand loaded into bucket 6 can be suppressed, and therefore, during loading work, etc., the difference between the weight of earth and sand calculated by weight calculation unit 61 and the weight of earth and sand discharged onto the bed of the dump truck can be reduced. Therefore, according to this embodiment, the accuracy of measuring the weight of earth and sand can be improved, and productivity can be improved.

[0307] In the above embodiment, the controller 30 is mounted on the shovel 100, but it may also be installed outside the shovel 100. In this case, the controller 30 may be a control device installed in, for example, a remote control room. In this case, the controller 30 may instruct the shovel 100 to execute suppression control when it is determined that the state of the soil and sand is such that spillage is likely to occur.

[0308] Furthermore, in each of the above-described embodiments, the shovel 100 has been described as an example of a work machine, but the work machine is not limited to a shovel.

[0309] The present embodiment has been described above with reference to specific examples. However, the present invention is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art are also included within the scope of the present invention as long as they comprise the features of the present invention. The elements of each of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and may be modified as appropriate. The elements of each of the above-described specific examples may be combined as appropriate as long as no technical contradictions arise. [Explanation of symbols]

[0310] 30 Controllers 40 Display device 60 Soil weight processing section 61 Weight calculation section 62 Maximum load detector 63 Load calculation unit 64 Remaining load calculation unit 65 Center of gravity calculation part 66 Status determination unit 67 Inhibition control section 100 Shovel

Claims

1. Lower running and An upper rotating body; a hydraulic actuator mounted on the upper rotating body; A spatial recognition device, a center of gravity calculation unit that calculates the center of gravity of the soil in the bucket; a state determination unit that acquires information indicating the state of the soil and sand, including the shape of the image of the soil and sand in the bucket acquired by the spatial recognition device and the position of the center of gravity of the soil and sand in the bucket, and determines that the state of the soil and sand is prone to spilling if the state of the soil and sand satisfies predetermined conditions; a control unit that controls the hydraulic actuator in accordance with the state of the soil in the bucket after excavation; a weight calculation unit that calculates the weight of the soil and sand in the bucket, The state determination unit When the bucket after the excavation is raised to a predetermined height, the state of the earth and sand is determined; The weight calculation unit A shovel that calculates the weight of the earth and sand in the bucket when the bucket is further raised to a predetermined height after the state of the earth and sand has been determined by the state determination unit.

2. The control unit The shovel according to claim 1 , wherein the rotation angular velocity of the upper rotating body is limited when the state of the soil and sand satisfies the predetermined condition.

3. The control unit The shovel according to claim 1 or 2, wherein a bucket angle of the bucket is controlled when the state of the soil and sand satisfies the predetermined condition.

Images