Control device for work machine

Abstract

To provide a control device of a working machine capable of reducing detection omission of weight of an object held by a working tool.SOLUTION: A control device for a work machine includes a control unit configured to control a work machine including a work machine main body, an attachment attached to the work machine main body, and a work tool provided at a distal end of the attachment, and the control unit is configured to determine whether or not detection information on a lifting operation of the attachment satisfies a plurality of conditions after holding an object on the work tool, and detect a weight of the object based on the detection information when one or more of the plurality of conditions are satisfied.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present disclosure relates to a control device for a work machine. [Background technology]

[0002] Various techniques have been proposed for loading objects such as earth and sand onto the bed of a dump truck using an excavator. For example, the technique described in Patent Document 1 compensates for the torque that rotates the attachment in order to suppress fluctuations in the calculated weight of earth and sand due to disturbances, and calculates the weight of the object to be transported by the attachment based on the compensated torque. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 124319 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology disclosed in Patent Document 1, the weight of an object is calculated when the boom is lifted, but since the condition for calculating the weight is only the lifting of the boom, there is a possibility that the weight of the object may not be detected.

[0005] One aspect of the present disclosure provides a shovel that can reduce the amount of undetected weight of an object held by the implement. [Means for solving the problem]

[0006] A work machine control device according to one aspect of the present disclosure includes a control unit configured to control a work machine having a work machine body, an attachment attached to the work machine body, and a work implement provided at the tip of the attachment, and the control unit is configured to, after holding an object on the work implement, determine whether detection information related to the lifting operation of the attachment satisfies multiple conditions, and if one or more of the multiple conditions are satisfied, detect the weight of the object based on the detection information. [Effects of the Invention]

[0007] According to one aspect of the present disclosure, the weight of an object held by a work tool is detected if one or more of a plurality of conditions are met, thereby reducing the number of missed detections of the weight of an object held by a work tool. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a shovel according to an embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a drive system of a shovel according to an embodiment. [Figure 3] FIG. 1 is a diagram illustrating an example of a configuration of a hydraulic system of a shovel according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of components related to an operation system in the hydraulic system of the excavator according to the embodiment. [Figure 5] FIG. 1 is a diagram illustrating a configuration example of an electric operation system for a shovel according to an embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of components related to a sediment load detection function of the excavator according to the embodiment. [Figure 7] 1A to 1C are diagrams illustrating deep excavation and loading operations of the excavator according to the embodiment. [Figure 8] FIG. 2 is a diagram showing the appearance of a shovel for explaining parameters used for control in the embodiment. [Figure 9] FIG. 1 is a schematic diagram of an attachment for a shovel showing the relationship between the opening and closing operation of the arm and the torque around the foot pin of the boom. [Figure 10] FIG. 4 is a block diagram illustrating the processing of a load weight calculation unit. [Figure 11] FIG. 10 is another block diagram illustrating the processing of the load weight calculation unit. [Figure 12] 10 is a flowchart illustrating an example of a load weight determination process according to the embodiment. [Figure 13] FIG. 10 is a diagram showing an example of a main screen displayed on the display device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are merely examples and do not limit the invention, and all features and combinations described in the embodiments are not necessarily essential to the invention. In addition, identical or corresponding components in each drawing are designated by identical or corresponding reference numerals, and descriptions thereof may be omitted.

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

[0011] 1, the excavator 100 is positioned on a horizontal plane facing the upward slope ES of the construction target, and also shows an upward slope BS (i.e., the slope shape of the upward slope ES after construction), which is an example of a target construction surface to be described later. Note that the upward slope ES of the construction target is provided with a cylinder (not shown) that indicates the normal direction of the upward slope BS, which is the target construction surface.

[0012] The excavator 100 according to this embodiment includes a lower traveling body 1, an upper rotating body 3 mounted on the lower traveling body 1 so as to be rotatable via a rotating mechanism 2, a boom 4, an arm 5, and a bucket 6 that constitute an attachment (work machine), and a cabin 10. The lower traveling body 1 and the upper rotating body 3 constitute the main body of the work machine.

[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 instead of the bucket 6, other end attachments, such as a slope bucket, a dredging bucket, a breaker, a lifting magnet, a grapple, a fork, or a harvester including a chainsaw, may be attached to the tip of the arm 5 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] [Excavator configuration] Next, a specific configuration of the shovel 100 according to this embodiment will be described with reference to Fig. 2 in addition to Fig. 1. Fig. 2 is a diagram schematically showing an example of the configuration of a drive system of the shovel according to this embodiment. 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] The control valve 17 is a hydraulic control device mounted, for example, at the center of the upper swing 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. Specifically, the control valve 17 includes control valves 171 to 176 that control the flow rate and direction of hydraulic oil supplied from the main pump 14 to each of the hydraulic actuators. More specifically, the control valve 171 corresponds to the travel hydraulic motor 1L, the control valve 172 corresponds to the travel hydraulic motor 1R, and the control valve 173 corresponds to the swing hydraulic motor 2A. Furthermore, the control valve 174 corresponds to the bucket cylinder 9, the control valve 175 corresponds to the boom cylinder 7, and the control valve 176 corresponds to the arm cylinder 8. Furthermore, the control valve 175 includes, for example, control valves 175L and 175R as described later, and the control valve 176 includes, for example, control valves 176L and 176R as described later. The control valves 171 to 176 will be described in detail later.

[0025] 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.

[0026] 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.

[0027] The operation device (an example of an operation unit) 26 is provided near the driver's seat of the cabin 10. The operation device 26 is an operation input means by which the operator operates various operating elements (undercarriage 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc.). In other words, the operation device 26 is an operation input means by which the operator operates the hydraulic actuators that drive the respective operating elements (i.e., traveling hydraulic motors 1L, 1R, swing hydraulic motor 2A, boom cylinder 7, arm cylinder 8, bucket cylinder 9, etc.).

[0028] The operation devices 26 are connected to the control valves 17 directly through secondary pilot lines or indirectly via shuttle valves 32 (described later) provided in the secondary pilot lines. This allows pilot pressures corresponding to the operation states of the undercarriage 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc. in the operation devices 26 to be input to the control valves 17. Therefore, the control valves 17 can drive the respective hydraulic actuators according to the operation states of the operation devices 26.

[0029] 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) (see FIG. 4). The operating device 26 also includes, for example, lever devices and pedal devices that operate the pair of left and right crawlers (travel hydraulic motors 1L, 1R) of the lower traveling body 1.

[0030] The shuttle valve 32 has two inlet ports and one outlet port. The shuttle valve 32 outputs hydraulic oil having the 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. The outlet port of the shuttle valve 32 is connected to the pilot port of the corresponding control valve in the control valve 17 via a pilot line (see FIG. 4 for details). Therefore, the shuttle valve 32 can apply the higher of the pilot pressure generated by the operating device 26 or the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve. In other words, the controller 30 (described later) can control the corresponding control valve and the operation 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. The shuttle valve 32 includes, for example, shuttle valves 32AL, 32AR, 32BL, 32BR, 32CL, and 32CR, as will be described later.

[0031] 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 47, 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 P1, and a communication device T1.

[0032] 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.

[0033] 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. Also, 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.

[0034] Furthermore, for example, the controller 30 performs control related to a machine guidance function that guides (instructs) the operator in manually operating the shovel 100 via the operation device 26. Furthermore, the controller 30 performs control related to a machine control function that automatically assists the operator in manually operating the shovel 100 via the operation device 26. In other words, the controller 30 includes a machine guidance unit 50 as a functional unit related to the machine guidance function and the machine control function. Furthermore, the controller 30 includes a sediment load processing unit 60, which will be described later.

[0035] 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).

[0036] 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.

[0037] 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 (for example, operation content such as operation direction or operation amount) of each operating element (i.e., hydraulic actuator) in the operating device 26. A detection signal of the pilot pressure by the operating pressure sensor 29 corresponding to the operating state of the undercarriage 1, upper rotating body 3, boom 4, arm 5, bucket 6, etc. in the operating device 26 is taken into the controller 30. The operating pressure sensor 29 includes, for example, operating pressure sensors 29A to 29C, as described below.

[0038] 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.

[0039] 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. As a result, even when the operating device 26 (specifically, the lever devices 26A to 26C) is not being operated by the operator, the controller 30 can supply 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 described below.

[0040] 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.

[0041] 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 a display device 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. 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.

[0042] 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.

[0043] The storage device 47 is provided, for example, in the cabin 10, and stores various pieces of information under the control of the controller 30. The storage device 47 is, for example, a non-volatile storage medium such as a semiconductor memory. The storage device 47 may store information output by various devices during operation of the shovel 100, or may store information obtained via various devices before operation of the shovel 100 is started. The storage device 47 may store, for example, data related to a target construction plane that is obtained 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.

[0044] The boom angle sensor S1 is attached to the boom 4 and detects the elevation / depression angle of the boom 4 relative to the upper rotating structure 3 (hereinafter referred to as the "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 structure 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. The boom angle sensor S1 may also include a potentiometer using a variable resistor, a cylinder sensor that detects the stroke amount of a hydraulic cylinder (boom cylinder 7) corresponding to the boom angle, etc. The same applies to the arm angle sensor S2 and the bucket angle sensor S3 below. A detection signal corresponding to the boom angle detected by the boom angle sensor S1 is input to the controller 30.

[0045] 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.

[0046] 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 (toe) 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.

[0047] The machine body tilt sensor S4 detects the tilt state of the machine body (the upper rotating body 3 or the undercarriage 1) relative to a horizontal plane. The machine body tilt sensor S4 is attached to, for example, the upper rotating body 3, and detects the tilt angles of the excavator 100 (i.e., the upper rotating body 3) about two axes in the fore-aft and lateral directions (hereinafter referred to as the "fore-aft tilt angle" and the "lateral tilt angle"). The machine body tilt sensor S4 may include, for example, a rotary encoder, an acceleration sensor, a six-axis sensor, an IMU, etc. The detection signals corresponding to the tilt angles (fore-aft tilt angle and lateral tilt angle) detected by the machine body tilt sensor S4 are input to the controller 30.

[0048] 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 signal corresponding to the rotation angle and rotation angular velocity of the upper rotating body 3 detected by the rotation state sensor S5 is input to the controller 30. The boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine body inclination sensor S4, and the rotation state sensor S5 are included in the attitude sensors. The attitude sensor detects not only the toe position of the bucket 6 but also the boom angle, boom angular velocity, boom angular acceleration, etc.

[0049] The imaging device S6, which serves as a spatial recognition device, captures images of the periphery of the shovel 100. The imaging device S6 includes a front camera S6F that captures images in front of the shovel 100, a left camera S6L that captures images to the left of the shovel 100, a right camera S6R that captures images to the right of the shovel 100, and a rear camera S6B that captures images behind the shovel 100.

[0050] The front camera S6F is attached, for example, to the ceiling of the cabin 10, i.e., inside the cabin 10. The front camera S6F may also be attached to the outside of the cabin 10, such as on the roof of the cabin 10 or on the side of the boom 4. The left camera S6L is attached to the left end of the top surface of the upper rotating body 3, the right camera S6R is attached to the right end of the top surface of the upper rotating body 3, and the rear camera S6B is attached to the rear end of the top surface of the upper rotating body 3.

[0051] 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.

[0052] 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, animals, vehicles, construction machinery, buildings, holes, etc. The imaging device S6 may also 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 range image sensor, etc. The spatial recognition device is, for example, a monocular camera having an imaging element such as a CCD or a CMOS, and outputs a 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, a millimeter-wave radar, a LiDAR (Light Detection and Ranging), an infrared sensor, etc. may also be provided as the spatial recognition device. When a millimeter wave radar, an ultrasonic sensor, a laser radar, or the like is used as the spatial recognition device 80, a number of signals (laser light, etc.) may be emitted to an object, and the reflected signals may be received, from which the distance and direction of the object may be detected.

[0053] The imaging device S6 may be directly connected to the controller 30 so as to be able to communicate with it.

[0054] A boom rod pressure sensor S7R, a boom bottom pressure sensor S7B, and a boom cylinder stroke sensor S7C are attached to the boom cylinder 7. An arm rod pressure sensor S8R, an arm bottom pressure sensor S8B, and an arm cylinder stroke sensor S8C are attached to the arm cylinder 8. A bucket rod pressure sensor S9R, a bucket bottom pressure sensor S9B, and a bucket cylinder stroke sensor S9C are attached to the bucket cylinder 9. The boom rod pressure sensor S7R, the boom bottom pressure sensor S7B, the boom cylinder stroke sensor S7C, the arm rod pressure sensor S8R, the arm bottom pressure sensor S8B, the arm cylinder stroke sensor S8C, the bucket rod pressure sensor S9R, the bucket bottom pressure sensor S9B, and the bucket cylinder stroke sensor S9C are collectively referred to as the "cylinder pressure sensors."

[0055] The boom rod pressure sensor S7R detects the pressure (boom rod pressure) in the rod-side oil chamber of the boom cylinder 7. The boom bottom pressure sensor S7B detects the pressure (boom bottom pressure) in the bottom-side oil chamber of the boom cylinder 7. The boom cylinder stroke sensor S7C detects the stroke amount of the boom cylinder 7 (boom stroke amount).

[0056] The arm rod pressure sensor S8R detects the pressure (arm rod pressure) in the rod-side oil chamber of the arm cylinder 8. The arm bottom pressure sensor S8B detects the pressure (arm bottom pressure) in the bottom-side oil chamber of the arm cylinder 8. The arm cylinder stroke sensor S8C detects the stroke amount of the arm cylinder 8 (arm stroke amount).

[0057] The bucket rod pressure sensor S9R detects the pressure (bucket rod pressure) in the rod-side oil chamber of the bucket cylinder 9. The bucket bottom pressure sensor S9B detects the pressure (bucket bottom pressure) in the bottom-side oil chamber of the bucket cylinder 9. The bucket cylinder stroke sensor S9C detects the stroke amount of the bucket cylinder 9 (bucket stroke amount).

[0058] The positioning device P1 measures the position and orientation of the upper rotating body 3. The positioning device P1 is, for example, a Global Navigation Satellite System (GNSS) 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, the function of detecting the orientation of the upper rotating body 3, which is one of the functions of the positioning device P1, may be substituted by a direction sensor attached to the upper rotating body 3.

[0059] The communication device T1 communicates with external devices through a predetermined network including a mobile communication network with a base station as an end, a satellite communication network, the Internet, etc. 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.

[0060] The machine guidance unit 50, for example, controls the excavator 100 with respect to the machine guidance function. The machine guidance unit 50 communicates 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. Data regarding the target construction surface is, for example, pre-stored in the storage device 47, as described above. Data regarding 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 the origin at the center of gravity of the Earth, the X axis pointing toward the intersection of the Greenwich meridian and the equator, the Y axis pointing toward 90 degrees east longitude, and the Z axis pointing toward the North Pole. The operator may designate any point on the construction site as a reference point and set the target construction surface relative to the reference point via the input device 42. The working part of the bucket 6 is, for example, the tip of the bucket 6, the back of the bucket 6, etc. Furthermore, if, for example, a breaker is used as the end attachment instead of the bucket 6, the tip of the breaker 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.

[0061] 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 the target construction surface.

[0062] The machine guidance unit 50 acquires information from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine body inclination sensor S4, swing state sensor S5, imaging device S6, positioning device P1, communication device T1, input device 42, etc. Then, the machine guidance unit 50 calculates the distance between the bucket 6 and the target construction surface based on the acquired information, notifies the operator of the distance between the bucket 6 and the target construction surface by audio from the audio output device 43 and an image displayed on the display device 40, and automatically controls the operation of the attachment so that the tip of the attachment (specifically, working parts such as the tip and back of the bucket 6) coincides with the target construction surface. The machine guidance unit 50 includes a position calculation unit 51, a distance calculation unit 52, an information transmission unit 53, a control unit 54, and a swing angle calculation unit 55 as detailed functional configurations related to the machine guidance function and the machine control function.

[0063] 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).

[0064] 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, the working part such as the tip or back of bucket 6, and the target construction surface. Distance calculation unit 52 may also calculate the angle (relative angle) between the back of bucket 6 as the working part and the target construction surface.

[0065] The information transmission unit 53 transmits (notifies) various pieces of information to the operator of the excavator 100 through predetermined notification means such as the display device 40 and the audio output device 43.

[0066] The control unit 54 individually adjusts 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) in accordance with the operator's manual operation of the excavator 100 via the operation device 26. In this way, the control unit 54 can realize the operation of the hydraulic actuators in accordance with the operation of the operator.

[0067] The slewing angle calculation unit 55 calculates the slewing angle of the upper slewing body 3. This allows the controller 30 to identify the current orientation of the upper slewing body 3. The slewing angle calculation unit 55 calculates the angle of the front-to-rear axis of the upper slewing body 3 relative to a reference direction as the slewing angle, for example, based on the output signal of a GNSS compass included in the positioning device P1. The slewing angle calculation unit 55 may also calculate the slewing angle based on a detection signal from the slewing state sensor S5. Furthermore, if a reference point is set at the construction site, the slewing angle calculation unit 55 may use the direction of the reference point as seen from the slewing axis as the reference direction.

[0068] The rotation angle indicates the direction in which the attachment operating plane extends relative to the reference direction. The attachment operating plane is, for example, an imaginary plane that cuts the attachment longitudinally and is positioned so as to be perpendicular to the rotation plane. The rotation plane is, for example, an imaginary plane that includes the bottom surface of the rotating frame that is perpendicular to the rotation axis. For example, when the controller 30 (machine guidance unit 50) determines that the upper rotating body 3 is directly facing the target construction surface, the controller 30 (machine guidance unit 50) determines that the attachment operating plane includes the normal to the target construction surface.

[0069] The rotation angle calculated by the rotation angle calculation unit 55 may be displayed as visual information on the display device 40 by the information transmission unit 53. The rotation angle may also be used as a condition for the sediment load processing unit 60 to measure the sediment weight (for example, to determine whether the upper rotating body 3 has rotated).

[0070] 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.

[0071] 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 the 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.

[0072] [Excavator hydraulic system] Next, the hydraulic system of the shovel 100 according to this embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram schematically showing an example of the configuration of the hydraulic system of the shovel according to this embodiment. 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 the like.

[0073] The hydraulic system realized by the hydraulic circuit shown in Figure 3 circulates hydraulic oil from each of the main pumps 14L, 14R driven by the engine 11, via center bypass oil passages C1L, C1R and parallel oil passages C2L, C2R to a hydraulic oil tank.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] The control valves 176L and 176R are spool valves that supply the hydraulic oil discharged from the main pumps 14L and 14R to the arm cylinder 8 and discharge the hydraulic oil in the arm cylinder 8 to a hydraulic oil tank, respectively.

[0082] 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.

[0083] The parallel oil passage C2L supplies hydraulic oil for the main pump 14L to the control valves 171, 173, 175L, and 176L in parallel with the center bypass oil passage C1L. 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.

[0084] 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. This allows the parallel oil passage C2R to supply hydraulic oil to a downstream control valve 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.

[0085] 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.

[0086] 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 is true for 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.

[0087] Negative control throttles (hereinafter referred to as "negative control throttles") 18L, 18R are provided in the center bypass oil passages C1L, C1R 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 negative control throttles 18L, 18R. The negative control throttles 18L, 18R then generate a control pressure (hereinafter referred to as "negative control pressure") for controlling the regulators 13L, 13R.

[0088] The negative control pressure sensors 19L and 19R detect the negative control pressure. The detection signals corresponding to the negative control pressures detected by the negative control pressure sensors 19L and 19R are input to the controller 30.

[0089] 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.

[0090] The controller 30 may also adjust the discharge rates of the main pumps 14L, 14R by controlling the regulators 13L, 13R in accordance with the negative control pressure detected by the negative control pressure sensors 19L, 19R. For example, the controller 30 decreases the discharge rates of the main pumps 14L, 14R as the negative control pressure increases, and increases the discharge rates of the main pumps 14L, 14R as the negative control pressure decreases.

[0091] 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 negative control throttles 18L, 18R. The flow of the hydraulic oil discharged from the main pumps 14L, 14R increases the negative control pressure generated upstream of the negative control 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.

[0092] On the other hand, when any of the hydraulic actuators is operated via 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. The flow of hydraulic oil discharged from the main pumps 14L, 14R reduces or eliminates the amount of hydraulic oil reaching the negative control throttles 18L, 18R, lowering the negative control pressure generated upstream of the negative control throttles 18L, 18R. As a result, the controller 30 increases the discharge rate of the main pumps 14L, 14R, circulating sufficient hydraulic oil to the hydraulic actuator to be operated, thereby reliably driving the hydraulic actuator to be operated.

[0093] [Configuration details for excavator machine control functions] Next, details of the configuration related to the machine control function of the shovel 100 will be described with reference to Fig. 4. Fig. 4 is a diagram that schematically shows an example of components related to an operation system in the hydraulic system of the shovel according to this embodiment.

[0094] Specifically, Fig. 4(A) is a diagram showing an example of a pilot circuit that applies pilot pressure to control valves 175L, 175R that hydraulically control the boom cylinder 7. Fig. 4(B) is a diagram showing an example of a pilot circuit that applies pilot pressure to a control valve 174 that hydraulically controls the bucket cylinder 9. Fig. 4(C) is a diagram showing an example of a pilot circuit that applies pilot pressure to a control valve 173 that hydraulically controls the swing hydraulic motor 2A.

[0095] As shown in FIG. 4(A), lever device 26A is used by an operator or the like to operate boom cylinder 7 corresponding to boom 4. Lever device 26A uses hydraulic oil discharged from pilot pump 15 to output pilot pressure to the secondary side according to the operation content.

[0096] The shuttle valve 32AL has two inlet ports connected to the secondary pilot line of the lever device 26A corresponding to the operation of the boom 4 in the raising direction (hereinafter referred to as the "boom raising operation") and the secondary pilot line of the proportional valve 31AL, and an outlet port connected to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R.

[0097] The shuttle valve 32AR has two inlet ports connected to the secondary pilot line of the lever device 26A corresponding to the operation of lowering the boom 4 (hereinafter referred to as the "boom lowering operation") and the secondary pilot line of the proportional valve 31AR, respectively, and an outlet port connected to the right pilot port of the control valve 175R.

[0098] That is, lever device 26A applies a pilot pressure corresponding to the operation content (e.g., the operation direction and operation amount) to the pilot ports of control valves 175L and 175R via shuttle valves 32AL and 32AR. Specifically, when a boom-up operation is performed, lever device 26A outputs a pilot pressure corresponding to the operation amount to one inlet port of shuttle valve 32AL, and applies the pilot pressure to the right pilot port of control valve 175L and the left pilot port of control valve 175R via shuttle valve 32AL. Furthermore, when a boom-down operation is performed, lever device 26A outputs a pilot pressure corresponding to the operation amount to one inlet port of shuttle valve 32AR, and applies the pilot pressure to the right pilot port of control valve 175R via shuttle valve 32AR.

[0099] The proportional valve 31AL operates in response to a control current input from the controller 30. Specifically, the proportional valve 31AL uses the hydraulic oil discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other inlet port of the shuttle valve 32AL. This allows the proportional valve 31AL to adjust the pilot pressure acting on the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the shuttle valve 32AL.

[0100] The proportional valve 31AR operates in response to a control current input from the controller 30. Specifically, the proportional valve 31AR uses the hydraulic oil discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other inlet port of the shuttle valve 32AR. This allows the proportional valve 31AR to adjust the pilot pressure acting on the right pilot port of the control valve 175R via the shuttle valve 32AR.

[0101] That is, the proportional valves 31AL, 31AR can adjust the pilot pressure output to the secondary side so that the control valves 175L, 175R can be stopped at any valve position, regardless of the operating state of the lever device 26A.

[0102] The proportional valve 33AL functions as a control valve for machine control, similar to the proportional valve 31AL. The proportional valve 33AL is disposed in a pipe connecting the operating device 26 and the shuttle valve 32AL, and is configured to be able to change the flow path area of ​​the pipe. In this embodiment, the proportional valve 33AL operates in response to a control command output by the controller 30. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 can reduce the pressure of the hydraulic oil discharged by the operating device 26 and supply it to the pilot port of the corresponding control valve in the control valve 17 via the shuttle valve 32AL.

[0103] Similarly, the proportional valve 33AR functions as a control valve for machine control. The proportional valve 33AR is disposed in a pipe connecting the operating device 26 and the shuttle valve 32AR, and is configured to be able to change the flow path area of ​​the pipe. In this embodiment, the proportional valve 33AR operates in response to a control command output by the controller 30. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 can reduce the pressure of the hydraulic oil discharged by the operating device 26 and supply it to the pilot port of the corresponding control valve in the control valve 17 via the shuttle valve 32AR.

[0104] The operation pressure sensor 29A detects the operation of the lever device 26A by the operator in the form of pressure (operation pressure). A detection signal corresponding to the operation pressure detected by the operation pressure sensor 29A is input to the controller 30. This allows the controller 30 to grasp the operation of the lever device 26A.

[0105] The controller 30 can supply hydraulic oil discharged 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 31AL and the shuttle valve 32AL, regardless of the operator's boom-raising operation of the lever device 26A. Furthermore, the controller 30 can supply hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31AR and the shuttle valve 32AR, regardless of the operator's boom-lowering operation of the lever device 26A. In other words, the controller 30 can automatically control the raising and lowering operation of the boom 4. Furthermore, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to a specific operating device 26, even when the specific operating device 26 is being operated.

[0106] The proportional valve 33AL operates in response to a control command (current command) output by the controller 30. It reduces the pilot pressure of 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 lever device 26A, proportional valve 33AL, and shuttle valve 32AL. The proportional valve 33AR operates in response to a control command (current command) output by the controller 30. It reduces the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 175R via the lever device 26A, proportional valve 33AR, and shuttle valve 32AR. The proportional valves 33AL and 33AR are capable of adjusting the pilot pressure so that the control valves 175L and 175R can be stopped at any valve position.

[0107] With this configuration, even when the operator is performing a boom-raising operation, the controller 30 can, as necessary, reduce the pilot pressure acting on the pilot ports on the raising side of the control valve 175 (the left pilot port of the control valve 175L and the right pilot port of the control valve 175R) to forcibly stop the closing operation of the boom 4. The same applies to the case where the lowering operation of the boom 4 is forcibly stopped when the operator is performing a boom-lowering operation.

[0108] Alternatively, even when the operator is performing a boom-raising operation, the controller 30 may control the proportional valve 31AR as necessary to increase the pilot pressure acting on the lowering pilot port of the control valve 175 (the right pilot port of the control valve 175R) opposite the raising pilot port of the control valve 175, thereby forcibly returning the control valve 175 to the neutral position, thereby forcibly stopping the raising operation of the boom 4. In this case, the proportional valve 33AL may be omitted. The same applies to the case where the lowering operation of the boom 4 is forcibly stopped when the operator is performing a boom-lowering operation.

[0109] As shown in FIG. 4(B), lever device 26B is used by an operator or the like to operate bucket cylinder 9 corresponding to bucket 6. Lever device 26B uses hydraulic oil discharged from pilot pump 15 to output pilot pressure to the secondary side according to the operation content.

[0110] The shuttle valve 32BL has two inlet ports connected to the secondary pilot line of the lever device 26B corresponding to the operation in the closing direction of the bucket 6 (hereinafter referred to as the "bucket closing operation") and the secondary pilot line of the proportional valve 31BL, respectively, and an outlet port connected to the left pilot port of the control valve 174.

[0111] The shuttle valve 32BR has two inlet ports connected to the secondary pilot line of the lever device 26B corresponding to the operation of the bucket 6 in the opening direction (hereinafter referred to as the "bucket opening operation") and the secondary pilot line of the proportional valve 31BR, respectively, and an outlet port connected to the right pilot port of the control valve 174.

[0112] In other words, lever device 26B applies a pilot pressure corresponding to the operation content to the pilot port of control valve 174 via shuttle valves 32BL, 32BR. Specifically, when a bucket closing operation is performed, lever device 26B outputs a pilot pressure corresponding to the operation amount to one inlet port of shuttle valve 32BL, and applies the pilot pressure to the left pilot port of control valve 174 via shuttle valve 32BL. Furthermore, when a bucket opening operation is performed, lever device 26B outputs a pilot pressure corresponding to the operation amount to one inlet port of shuttle valve 32BR, and applies the pilot pressure to the right pilot port of control valve 174 via shuttle valve 32BR.

[0113] The proportional valve 31BL operates in response to a control current input from the controller 30. Specifically, the proportional valve 31BL uses hydraulic oil discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32BL. This allows the proportional valve 31BL to adjust the pilot pressure acting on the left pilot port of the control valve 174 via the shuttle valve 32BL.

[0114] The proportional valve 31BR operates in response to a control current input from the controller 30. Specifically, the proportional valve 31BR uses the hydraulic oil discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32BR. This allows the proportional valve 31BR to adjust the pilot pressure acting on the right pilot port of the control valve 174 via the shuttle valve 32BR.

[0115] That is, the proportional valves 31BL, 31BR can adjust the pilot pressure output to the secondary side so that the control valve 174 can be stopped at any valve position, regardless of the operating state of the lever device 26B.

[0116] The proportional valve 33BL functions as a control valve for machine control, similar to the proportional valve 31BL. The proportional valve 33BL is disposed in a pipeline connecting the operating device 26 and the shuttle valve 32BL, and is configured to be able to change the flow path area of ​​the pipeline. In this embodiment, the proportional valve 33BL operates in response to a control command output by the controller 30. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 can reduce the pressure of the hydraulic oil discharged by the operating device 26 and supply it to the pilot port of the corresponding control valve in the control valve 17 via the shuttle valve 32BL.

[0117] Similarly, the proportional valve 33BR functions as a control valve for machine control. The proportional valve 33BR is disposed in a pipe connecting the operating device 26 and the shuttle valve 32BR, and is configured so that the flow path area of ​​the pipe can be changed. In this embodiment, the proportional valve 33BR operates in response to a control command output by the controller 30. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 can reduce the pressure of the hydraulic oil discharged by the operating device 26 and supply it to the pilot port of the corresponding control valve in the control valve 17 via the shuttle valve 32BR.

[0118] The operation pressure sensor 29B detects the operation of the lever device 26B by the operator in the form of pressure (operation pressure). A detection signal corresponding to the operation pressure detected by the operation pressure sensor 29B is input to the controller 30. This allows the controller 30 to grasp the operation of the lever device 26B.

[0119] Controller 30 can supply hydraulic oil discharged from pilot pump 15 to the left pilot port of control valve 174 via proportional valve 31BL and shuttle valve 32BL, regardless of the operator's operation of lever device 26B to close the bucket. Controller 30 can also supply hydraulic oil discharged from pilot pump 15 to the right pilot port of control valve 174 via proportional valve 31BR and shuttle valve 32BR, regardless of the operator's operation of lever device 26B to open the bucket. In other words, controller 30 can automatically control the opening and closing operation of bucket 6. Controller 30 can also forcibly stop the operation of the hydraulic actuator corresponding to a specific operating device 26, even when that specific operating device 26 is being operated.

[0120] The operation of proportional valves 33BL, 33BR, which forcibly stop the operation of bucket 6 when the operator is performing a bucket closing operation or a bucket opening operation, is similar to the operation of proportional valves 33AL, 33AR, which forcibly stop the operation of boom 4 when the operator is performing a boom raising operation or a boom lowering operation, and therefore a duplicated explanation will be omitted.

[0121] As shown in Fig. 4(C), the lever device 26C is used by an operator or the like to operate the swing hydraulic motor 2A corresponding to the upper swing body 3 (swing mechanism 2). The lever device 26C uses hydraulic oil discharged from the pilot pump 15 to output a pilot pressure to the secondary side according to the operation content.

[0122] The shuttle valve 32CL has two inlet ports connected to the secondary pilot line of the lever device 26C corresponding to the leftward rotation operation of the upper rotating body 3 (hereinafter referred to as "left rotation operation") and the secondary pilot line of the proportional valve 31CL, and an outlet port connected to the left pilot port of the control valve 173.

[0123] The shuttle valve 32CR has two inlet ports connected to the secondary pilot line of the lever device 26C corresponding to the rightward rotation operation of the upper rotating body 3 (hereinafter referred to as "right rotation operation") and the secondary pilot line of the proportional valve 31CR, and an outlet port connected to the right pilot port of the control valve 173.

[0124] That is, lever device 26C applies a pilot pressure corresponding to the operation in the left or right direction to the pilot port of control valve 173 via shuttle valves 32CL, 32CR. Specifically, when a left turn operation is performed, lever device 26C outputs a pilot pressure corresponding to the operation amount to one inlet port of shuttle valve 32CL, and applies the pilot pressure to the left pilot port of control valve 173 via shuttle valve 32CL. Furthermore, when a right turn operation is performed, lever device 26C outputs a pilot pressure corresponding to the operation amount to one inlet port of shuttle valve 32CR, and applies the pilot pressure to the right pilot port of control valve 173 via shuttle valve 32CR.

[0125] The proportional valve 31CL operates in response to a control current input from the controller 30. Specifically, the proportional valve 31CL uses the hydraulic oil discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32CL. This allows the proportional valve 31CL to adjust the pilot pressure acting on the left pilot port of the control valve 173 via the shuttle valve 32CL.

[0126] The proportional valve 31CR operates in response to a control current input from the controller 30. Specifically, the proportional valve 31CR uses the hydraulic oil discharged from the pilot pump 15 to output a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the shuttle valve 32CR. This allows the proportional valve 31CR to adjust the pilot pressure acting on the right pilot port of the control valve 173 via the shuttle valve 32CR.

[0127] That is, the proportional valves 31CL and 31CR can adjust the pilot pressure output to the secondary side so that the control valve 173 can be stopped at any valve position, regardless of the operating state of the lever device 26C.

[0128] The proportional valve 33CL functions as a control valve for machine control, similar to the proportional valve 31CL. The proportional valve 33CL is disposed in a pipe connecting the operating device 26 and the shuttle valve 32CL, and is configured to be able to change the flow path area of ​​the pipe. In this embodiment, the proportional valve 33CL operates in response to a control command output by the controller 30. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 can reduce the pressure of the hydraulic oil discharged by the operating device 26 and supply it to the pilot port of the corresponding control valve in the control valve 17 via the shuttle valve 32CL.

[0129] Similarly, the proportional valve 33CR functions as a control valve for machine control. The proportional valve 33CR is disposed in a pipe connecting the operating device 26 and the shuttle valve 32CR, and is configured so that the flow path area of ​​the pipe can be changed. In this embodiment, the proportional valve 33CR operates in response to a control command output by the controller 30. Therefore, regardless of the operation of the operating device 26 by the operator, the controller 30 can reduce the pressure of the hydraulic oil discharged by the operating device 26 and supply it to the pilot port of the corresponding control valve in the control valve 17 via the shuttle valve 32CR.

[0130] The operation pressure sensor 29C detects the operation state of the lever device 26C by the operator in the form of pressure (operation pressure). A detection signal corresponding to the operation pressure detected by the operation pressure sensor 29C is input to the controller 30. This allows the controller 30 to grasp the operation content of the lever device 26C in the left and right directions.

[0131] The controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31CL and the shuttle valve 32CL, regardless of the operator's left rotation operation of the lever device 26C. Furthermore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31CR and the shuttle valve 32CR, regardless of the operator's right rotation operation of the lever device 26C. In other words, the controller 30 can automatically control the left-right rotation operation of the upper rotating body 3. Furthermore, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to a specific operating device 26, even when the specific operating device 26 is being operated.

[0132] The operation of the proportional valves 33CL, 33CR, which forcibly stop the operation of the upper rotating body 3 when the operator is performing a rotation operation, is similar to the operation of the proportional valves 33AL, 33AR, which forcibly stop the operation of the boom 4 when the operator is performing a boom-raising or boom-lowering operation, and therefore redundant explanations will be omitted.

[0133] The excavator 100 may further include a configuration for automatically opening and closing the arm 5, and a configuration for automatically moving the lower traveling structure 1 forward or backward. In this case, of the hydraulic system, the components related to the operating system of the arm cylinder 8, the components related to the operating system of the traveling hydraulic motor 1L, and the components related to the operating system of the traveling hydraulic motor 1R may be configured similarly to the components related to the operating system of the boom cylinder 7, etc. (FIGS. 4(A) to 4(C)).

[0134] Furthermore, the shovel 100 may use the communication device T1, for example, to communicate with an external device (not shown) indirectly or directly.

[0135] Instead of or in addition to being configured to be operable by an operator inside the cabin 10, the shovel 100 may be configured to be remotely operable from outside the shovel 100. When the shovel 100 is remotely operated, the inside of the cabin 10 may be unmanned. The following description will be given on the assumption that the operation of the operator includes at least one of operation of the operating device 26 by the operator inside the cabin 10 and remote operation by an external operator.

[0136] Remote control includes, for example, a mode in which the shovel 100 is operated by an operation input related to an actuator of the shovel 100 performed by a predetermined external device. In this case, the shovel 100 may transmit, for example, image information (captured image) output by a front camera S6F that captures an image in front of the remote-controlled upper rotating body 3 to the external device via a communication device T1 described later. The external device may then display the received image information (captured image) on a display device provided in the external device (hereinafter referred to as a "remote control display device"). Furthermore, various information images (information screens) displayed on the display device 40 inside the cabin 10 of the shovel 100 may also be displayed on the remote control display device of the external device. This allows the operator of the external device to remotely control the shovel 100 while checking the display contents of, for example, captured images and information screens showing the surroundings of the shovel 100 displayed on the remote control display device. The excavator 100 may operate actuators and drive driven elements such as the lower running body 1 (left and right crawlers), upper rotating body 3, boom 4, arm 5, and bucket 6 in response to a remote control signal indicating the content of the remote control received from an external device by the communication device T1.

[0137] Furthermore, remote control may include, for example, a mode in which the shovel 100 is operated by an external voice input or gesture input to the shovel 100 by a person (e.g., a worker) in the vicinity of the shovel 100. Specifically, the shovel 100 recognizes voices uttered by nearby workers or gestures made by the workers through a voice input device (e.g., a microphone) or a gesture input device (e.g., an imaging device) mounted on the shovel 100 (the shovel itself). Then, the shovel 100 may operate actuators in accordance with the content of the recognized voices or gestures, and drive driven elements such as the lower traveling body 1 (left and right crawlers), upper rotating body 3, boom 4, arm 5, and bucket 6.

[0138] 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. In this case, the electric signal from the operating device 26 is input to the controller 30, and the controller 30 controls the control valves 171 to 176 in the control valve 17 in accordance with the input electric signal, thereby realizing the operation of various hydraulic actuators in accordance with the operation of the operating device 26. 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, solenoid valves that operate in accordance with electric signals from the controller 30 may be arranged between the pilot pump 15 and the pilot ports of the control valves 171 to 176. 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.

[0139] 5 is a diagram showing an example of the configuration of an electric operation system for a shovel according to this embodiment. Here, the operation device 26 is an electromagnetic operation lever, and the controller 30 suppresses vibration of the boom 4 by controlling the pilot pressure to the control valve 17 (control valve 175).

[0140] When an electric operation system equipped with an electric control lever is employed, the controller 30 can more easily execute autonomous control functions than when a hydraulic operation system equipped with a hydraulic control lever is employed. The electric operation system of FIG. 5 is an example of a boom operation system, and is mainly composed of a pilot pressure operated control valve 17, a lever device 26A as an electric operation lever, the controller 30, a solenoid valve 160 for boom-raising operation, and a solenoid valve 162 for boom-lowering operation. The electric operation system of FIG. 5 can also be similarly applied to arm operation systems, bucket operation systems, etc. Hereinafter, an electromagnetic operation lever or an electric operation lever will also be simply referred to as an "electric lever." The lever device 26A is an example of an electric lever.

[0141] The pilot pressure operated control valve 17 includes a control valve 175 (see FIG. 3) for the boom cylinder 7, a control valve 176 (see FIG. 3) for the arm cylinder 8, and a control valve 174 (see FIG. 3) for the bucket cylinder 9. The solenoid valve 160 is configured to be able to adjust the flow path area of ​​the pipe connecting the pilot pump 15 and the up-side pilot port of the control valve 175. The solenoid valve 162 is configured to be able to adjust the flow path area of ​​the pipe connecting the pilot pump 15 and the down-side pilot port of the control valve 175.

[0142] When manual operation is performed, the controller 30 generates a boom-raising operation signal (electrical signal) or a boom-lowering operation signal (electrical signal) in response to an operation signal (electrical signal) output by an operation signal generating section of the lever device 26A. The operation signal output by the operation signal generating section of the lever device 26A is an electric signal that changes in response to the amount and direction of operation of the lever device 26A.

[0143] Specifically, when lever device 26A is operated in the boom-up direction, controller 30 outputs a boom-raising operation signal (electrical signal) corresponding to the lever operation amount to solenoid valve 160. Solenoid valve 160 adjusts the flow path area according to the boom-raising operation signal (electrical signal) and controls the pilot pressure as a boom-raising operation signal (pressure signal) acting on a raising-side pilot port of control valve 175. Similarly, when lever device 26A is operated in the boom-lowering direction, controller 30 outputs a boom-lowering operation signal (electrical signal) corresponding to the lever operation amount to solenoid valve 162. Solenoid valve 162 adjusts the flow path area according to the boom-lowering operation signal (electrical signal) and controls the pilot pressure as a boom-lowering operation signal (pressure signal) acting on a lowering-side pilot port of control valve 175.

[0144] When performing autonomous control, the controller 30 generates a boom-raising operation signal (electrical signal) or a boom-lowering operation signal (electrical signal) in response to a corrective operation signal (electrical signal), instead of responding to an operation signal (electrical signal) output by an operation signal generating unit of the lever device 26A. The corrective operation signal may be an electric signal generated by the controller 30, or may be an electric signal generated by an external control device other than the controller 30.

[0145] [Configuration details for excavator earth load detection function] Next, details of the configuration related to the earth and sand load detection function of the shovel 100 according to this embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram schematically showing an example of components related to the earth and sand load detection function of the shovel according to this embodiment.

[0146] In addition to the above-described configuration, the controller 30 includes a sediment load processing unit 60 as a functional unit related to the function of detecting the load of sediment excavated by the bucket 6.

[0147] The earth and sand load processing unit 60 has a determination unit 61 , a load weight calculation unit 62 , a maximum load amount detection unit 63 , an added load amount calculation unit 64 , and a remaining load amount calculation unit 65 .

[0148] 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.

[0149] 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 dumping position (swing operation). Below the dumping position, the bed of a dump truck is located. Next, at the dumping position, the shovel 100 controls the attachment to dump the earth and sand in the bucket 6, thereby loading the earth and sand in the bucket 6 onto the bed of the dump truck (discharge operation). Next, the shovel 100 rotates the upper rotating body 3 to move the bucket 6 from the dumping position to the excavation position (swing operation). By repeating these operations, the shovel 100 loads the excavated earth and sand onto the bed of the dump truck.

[0150] The determination unit 61 determines whether or not a predetermined condition (determination condition) for determining the weight of soil and sand (an example of an object) loaded in the bucket 6 is satisfied. In this embodiment, the determination unit 61 determines whether or not a detection signal (an example of detection information) related to the raising operation of the boom 4 satisfies multiple conditions after soil and sand is loaded in the bucket 6. If the detection signal satisfies one or more of the multiple conditions, the determination unit 61 determines that the determination condition for determining the weight of soil and sand loaded in the bucket 6 (soil weight) has been satisfied. When the determination unit 61 determines that the determination condition has been satisfied, a loaded object weight calculation unit 62 (described later) determines the soil weight calculated based on the detection signal. Note that the number of detection signals used by the determination unit 61 for determination is not limited to one, and multiple detection signals may be used.

[0151] The first condition among the multiple conditions determined by the determination unit 61 is a condition related to the cushion function of the boom cylinder 7. Specifically, the determination unit 61 determines that the first condition is satisfied when the stroke of the boom cylinder 7 reaches a range (cushion area) where the cushion function works. The cushion function is a function that decelerates the piston of a hydraulic cylinder when the piston approaches the stroke end. The cushion function acts to reduce the impact when the piston of the hydraulic cylinder reaches the stroke end. For example, the cushion function can be realized by a method of reducing the flow rate of hydraulic oil by controlling a control valve, or by a method of configuring the hydraulic cylinder so that the flow rate of hydraulic oil decreases when the piston reaches the cushion area.

[0152] For example, the determination unit 61 may determine that the boom cylinder 7 has reached the cushion area when the boom angle detected by the boom angle sensor S1 is equal to or greater than a predetermined threshold. Alternatively, for example, the determination unit 61 may determine that the boom cylinder 7 has reached the cushion area when the boom stroke amount detected by the boom cylinder stroke sensor S7C is equal to or greater than a predetermined threshold. Alternatively, for example, the determination unit 61 may determine that the boom cylinder 7 has reached the cushion area when the amount of change in the boom rod pressure detected by the boom rod pressure sensor S7R or the amount of change in the boom bottom pressure detected by the boom bottom pressure sensor S7B is equal to or greater than a predetermined threshold. The amount of change in the boom rod pressure and the amount of change in the boom bottom pressure are amounts of change per unit time (i.e., differential values). In this way, the boom angle sensor S1, the boom cylinder stroke sensor S7C, the boom rod pressure sensor S7R, and the boom bottom pressure sensor S7B output detection signals related to the raising operation of the boom 4.

[0153] The second condition among the multiple conditions determined by the determination unit 61 is a condition related to the boom-raising operation. Specifically, the determination unit 61 determines that the second condition is satisfied when the boom-raising operation by the operator has stopped. If the operation system of the excavator 100 employs a hydraulic operation system, the determination unit 61 determines whether the boom-raising operation has stopped based on the pilot pressure corresponding to the operation state of the boom 4. If the operation system of the excavator 100 employs an electric operation system, the determination unit 61 determines whether the boom-raising operation has stopped based on the operation signal generated by the lever device 26A.

[0154] For example, the determination unit 61 may determine that the boom-raising operation has stopped when the pilot pressure corresponding to the operation state of the boom 4, detected by the operating pressure sensor 29, becomes equal to or less than a predetermined threshold. Furthermore, for example, the determination unit 61 may determine that the boom-raising operation has stopped when the lever device 26A stops outputting a boom-raising operation signal. Furthermore, for example, the determination unit 61 may determine that the boom-raising operation has stopped when the amount of change in the operation amount of the lever device 26A becomes equal to or less than a predetermined threshold. The amount of change in the operation amount of the lever device 26A is the amount of change per predetermined time unit (i.e., a differential value). In this way, the operating pressure sensor 29 and the lever device 26A output detection signals related to the raising operation of the boom 4.

[0155] A third condition among the multiple conditions determined by the determination unit 61 is a condition related to the height of the bucket 6. Specifically, the determination unit 61 determines that the third condition is met when the height of the bucket 6 reaches a predetermined height. The height of the bucket 6 is the distance from the ground to the bottom of the bucket 6. The height of the bucket 6 may be calculated by the distance calculation unit 52. The predetermined height may be set arbitrarily, and may be, for example, the height of the soil release position. For example, the determination unit 61 may determine that the height of the bucket 6 has reached the predetermined height when the distance calculated by the distance calculation unit 52 between the bottom of the bucket 6 and the ground is equal to or greater than a predetermined threshold. In this way, the distance calculation unit 52 outputs a detection signal related to the raising operation of the boom 4.

[0156] The fourth condition among the multiple conditions determined by the determination unit 61 is a condition related to the amount of lifting of the boom 4. Specifically, the determination unit 61 determines that the fourth condition is met when the amount of lifting of the boom 4 is sufficient. The amount of lifting of the boom 4 is the difference between the height of the boom 4 when the excavation operation is completed and the current height of the boom 4.

[0157] For example, the determination unit 61 may calculate the height of the boom 4 when the excavation operation is completed based on the boom angle and attachment dimensions when the excavation operation is completed, calculate the current height of the boom 4 based on the boom angle and attachment dimensions detected by the boom angle sensor S1, and determine that the amount of lifting of the boom 4 is sufficient when the difference between the height of the boom 4 when the excavation operation is completed and the current height of the boom 4 is equal to or greater than a predetermined threshold. Alternatively, for example, the determination unit 61 may calculate the height of the boom 4 when the excavation operation is completed based on the boom stroke amount and attachment dimensions when the excavation operation is completed, calculate the current height of the boom 4 based on the boom stroke amount and attachment dimensions detected by the boom cylinder stroke sensor S7C, and determine that the amount of lifting of the boom 4 is sufficient when the difference between the height of the boom 4 when the excavation operation is completed and the current height of the boom 4 is equal to or greater than a predetermined threshold. In this way, the boom angle sensor S1 and the boom cylinder stroke sensor S7C output detection signals related to the lifting operation of the boom 4.

[0158] The fifth condition among the multiple conditions determined by the determination unit 61 is a condition related to the acceleration at which the boom 4 moves. Specifically, the determination unit 61 determines that the fifth condition is met when the acceleration at which the boom 4 moves is within a predetermined range. The acceleration at which the boom 4 moves may be the angular acceleration around the foot pin of the boom 4. Note that the angular acceleration of the boom 4 around the foot pin is the amount of change in speed per unit time (i.e., a differential value).

[0159] For example, the determination unit 61 may calculate the angular acceleration of the boom 4 about the foot pin based on the boom angle detected by the boom angle sensor S1, and may determine that the acceleration at which the boom 4 moves is within a predetermined range if the angular acceleration of the boom 4 about the foot pin is equal to or greater than a predetermined lower limit and equal to or less than a predetermined upper limit. Furthermore, for example, the determination unit 61 may determine that the acceleration at which the boom 4 moves is within a predetermined range if the amount of change in the boom rod pressure detected by the boom rod pressure sensor S7R or the amount of change in the boom bottom pressure detected by the boom bottom pressure sensor S7B is equal to or greater than a predetermined lower limit and equal to or less than a predetermined upper limit. In this way, the boom angle sensor S1, the boom rod pressure sensor S7R, and the boom bottom pressure sensor S7B output detection signals related to the raising operation of the boom 4.

[0160] The fifth condition may be a condition related to the acceleration at which the arm 5 moves. For example, the determination unit 61 may calculate the angular acceleration of the arm 5 based on the arm angle detected by the arm angle sensor S2, and determine that the acceleration at which the arm 5 moves is within a predetermined range when the angular acceleration of the arm 5 is equal to or greater than a predetermined lower limit value and equal to or less than a predetermined upper limit value. In this way, the arm angle sensor S2 outputs a detection signal related to the raising operation of the boom 4.

[0161] The determination unit 61 determines the measurement accuracy of the sediment weight based on the condition determined to be satisfied by the detection signal among the multiple conditions. For example, the multiple conditions determined by the determination unit 61 may have information indicating the accuracy when the condition is satisfied predefined, and the determination unit 61 may determine the accuracy determined for the condition determined to be satisfied by the detection signal as the measurement accuracy of the sediment weight. When the determination unit 61 determines that two or more of the multiple conditions are satisfied, the determination unit 61 may determine the highest accuracy as the measurement accuracy of the sediment weight.

[0162] The measurement accuracy determined by the determination unit 61 may be displayed as visual information on the display device 40 by the information transmission unit 53. The information transmission unit 53 may associate the measurement accuracy determined by the determination unit 61 with the soil weight calculated by the load weight calculation unit 62 and display them on the display device 40. If the soil weight has been calculated multiple times, the information transmission unit 53 may display history information on the measurement accuracy and soil weight on the display device 40.

[0163] As an example, the determination unit 61 may determine that the measurement accuracy of the soil weight is high if a fifth condition related to the acceleration of movement of the boom 4 is satisfied. Furthermore, the determination unit 61 may determine that the measurement accuracy of the soil weight is medium if a second condition related to the boom raising operation, a third condition related to the height of the bucket 6, or a fourth condition related to the lifting amount of the boom 4 is satisfied. Furthermore, the determination unit 61 may determine that the measurement accuracy of the soil weight is low if a first condition related to the cushioning function of the boom cylinder 7 is satisfied.

[0164] When the height of the bucket 6 is included in a measurement section for measuring the weight of the soil or the like loaded in the bucket 6, the loaded object weight calculation section 62 calculates the weight of the soil in the bucket 6 based on the thrust of the boom cylinder 7 derived from the detection signal from the cylinder pressure sensor (measurement values ​​of the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B) and the center of gravity of the soil. The measurement section is a section in the height direction provided for calculating the weight of the soil in the bucket 6, and is determined depending on the embodiment.

[0165] The weight of the soil is calculated, for example, by balancing the torque around the base of the boom 4. Specifically, the thrust of the boom cylinder 7 increases due to the soil in the bucket 6, and the torque around the base of the boom 4 calculated from the thrust of the boom cylinder 7 also increases. The increase in torque matches the torque calculated from the soil weight and the center of gravity of the soil. In this way, the load weight calculation unit 62 calculates the soil weight based on the thrust of the boom cylinder 7 (measured values ​​from the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B) and the center of gravity of the soil derived from the detection signal. The center of gravity of the soil is determined in advance, for example, experimentally and stored in the controller 30.

[0166] Note that, although this embodiment will describe an example in which the weight of soil and sand is calculated based on the thrust of the boom cylinder 7, the method of calculating the weight of soil and sand is not limited to this. The load weight calculation unit 62 according to this embodiment may calculate the weight of soil and sand based on a detection signal detected as the operation of the attachment. For example, the load weight calculation unit 62 may calculate the weight of soil and sand based on the thrust of the arm cylinder 8 (measured values ​​of the arm rod pressure sensor S8R and the arm bottom pressure sensor S8B), or may calculate the weight of soil and sand based on the thrust of the bucket cylinder 9 (measured values ​​of the bucket rod pressure sensor S9R and the bucket bottom pressure sensor S9B).

[0167] The maximum load capacity detection unit 63 detects the maximum load capacity of a dump truck to be loaded with earth and sand. For example, the maximum load capacity detection unit 63 identifies the dump truck to be loaded with earth and sand based on an image captured by the imaging device S6. Next, the maximum load capacity detection unit 63 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 63 determines the vehicle type (size, etc.) of the dump truck based on the image of the identified dump truck. The maximum load capacity detection unit 63 has 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 via the input device 42, and the maximum load capacity detection unit 63 may calculate the maximum load capacity of the dump truck based on the input information from the input device 42.

[0168] The additional load amount calculation unit 64 calculates the weight of earth and sand loaded on the dump truck. That is, each time earth and sand in the bucket 6 is released onto the bed of the dump truck, the additional load amount calculation unit 64 adds the weight of earth and sand in the bucket 6 calculated by the load weight calculation unit 62 and calculates the additional load amount (total weight), which is the total weight of 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 additional load amount is reset.

[0169] The remaining load calculation unit 65 calculates the remaining load as the difference between the maximum load of the dump truck detected by the maximum load detection unit 63 and the current added load calculated by the added load calculation unit 64. The remaining load is the remaining weight of earth and sand that can be loaded onto the dump truck.

[0170] The display device 40 may also display the weight of soil in the bucket 6 calculated by the load weight calculation unit 62, the maximum load capacity of the dump truck detected by the maximum load capacity detection unit 63, the added load capacity of the dump truck (the total weight of soil loaded on the loading platform) calculated by the added load capacity calculation unit 64, and the remaining load capacity of the dump truck (the remaining weight of soil that can be loaded) calculated by the remaining load capacity calculation unit 65.

[0171] The display device 40 may be configured to issue a warning when the added load amount exceeds the maximum load amount. The display device 40 may also be configured to issue a warning when the calculated weight of earth and sand in the bucket 6 exceeds the remaining load amount. The warning does not have to be displayed on the display device 40, but may also be output as an audio message by the audio output device 43. This makes it possible to prevent earth and sand from being loaded in excess of the maximum load amount of the dump truck.

[0172] [Excavator digging and loading operations] Next, an example of the operation of the shovel 100 will be described with reference to Fig. 7. Fig. 7 is a diagram illustrating the deep excavation and loading operation of the shovel.

[0173] First, as shown in Figure 7(A), the operator lowers the boom. Then, the operator positions the tip of the bucket 6 at the desired height relative to the excavation target, and gradually closes the bucket 6 from the open state as shown in Figure 7(B). At this time, the excavated soil enters the bucket 6.

[0174] Next, with the upper edge of the bucket 6 held approximately horizontal, the operator raises the boom 4 to the position shown in Figure 7(C). At this time, the operator may also perform an operation to close the arm 5 while raising the boom 4.

[0175] Furthermore, when the height of the boom 4 reaches the measurement section during the raising operation of the boom 4, if the time during which it is determined that the angular acceleration around the foot pin of the boom 4 is smaller than the first threshold value and the amount of change in the cylinder thrust (differential value) is smaller than the second threshold value is longer than a predetermined time, the load weight calculation unit 62 calculates the weight of soil and sand in the bucket 6. Furthermore, if the conditions for calculating the soil and sand weight are not met, the information transmission unit 53 may warn the operator to perform an operation that will meet the conditions.

[0176] Then, as shown in FIG. 7(D), the operator raises the boom 4 until the bottom of the bucket 6 is at a desired height from the ground. The desired height is, for example, equal to or greater than the height of the dump truck DT (see FIG. 7(E) described later). Subsequently to, or simultaneously with, this, the operator rotates the upper rotating body 3 as shown by arrow AR1, and moves the bucket 6 to the position from which the soil will be discharged. The operation of the excavator at this time is called a boom-raising swing operation, and this operation section is called a boom-raising swing operation section.

[0177] When the operator completes the boom raising and swinging operation, he opens the arm 5 and the bucket 6 as shown in FIG. 7(E) and discharges the soil in the bucket 6. The operation of the excavator 100 at this time is called a dumping operation, and this operation section is called a dumping operation section. In the dumping operation, the operator may open only the bucket 6 to discharge the soil.

[0178] When the operator completes the dumping operation, as shown in Figure 7(F), he rotates the upper rotating body 3 as indicated by arrow AR2, and moves the bucket 6 directly above the excavation position. At this time, simultaneously with the rotation, the boom 4 is lowered to lower the bucket 6 to a desired height above the excavation target. The operation of the excavator at this time is called the boom lowering rotation operation, and this operation section is called the boom lowering rotation operation section.

[0179] The operator performs deep excavation and loading operations by repeating a cycle consisting of "digging operation," "boom raising and swinging operation," "dumping operation," and "boom lowering and swinging operation."

[0180] [Soil weight calculation method] Next, a method for calculating the weight of earth and sand (load) in the bucket 6 in the load weight calculation unit 62 of the excavator 100 according to this embodiment will be described with reference to FIGS. 8 to 11. FIG.

[0181] 8A and 8B are diagrams showing the appearance of a shovel for explaining parameters used for control in an embodiment. Fig. 8A is a side view of the shovel 100, and Fig. 8B is a front view of the shovel 100.

[0182] As shown in FIG. 8(A), the center of gravity of the soil (load) loaded in the bucket 6 is designated as soil gravity center G1. The position of the soil gravity center G1 relative to the bucket 6 is determined in advance, for example, experimentally and stored in the controller 30. The weight of the soil loaded in the bucket 6 is designated as soil weight W1. The angle formed by a line connecting the fulcrums at both ends of the boom 4 with respect to the rotation plane of the upper rotating body 3 is designated as boom angle θ1. The boom angle θ1 is detected by boom angle sensor S1. The angle formed by a line connecting the fulcrums at both ends of the boom 4 with respect to a line connecting the fulcrums at both ends of the arm 5 is designated as arm angle θ2. The arm angle θ2 is detected by arm angle sensor S2. The angle formed by a line connecting the fulcrum of the bucket 6 and the soil gravity center G1 with respect to a line connecting the fulcrums at both ends of the arm 5 is designated as bucket angle θ3. The bucket angle θ3 is detected by bucket angle sensor S3. The tilt angle of the shovel 100 in the front-to-rear direction is defined as a pitch angle θp. As shown in Fig. 8(B), the tilt angle of the shovel 100 in the left-to-right direction is defined as a roll angle θr. The pitch angle θp and the roll angle θr are detected by a machine body tilt sensor S4.

[0183] For example, when the determination unit 61 determines that the conditions for measuring the weight of the load are met when the boom 4 is raised after the excavation operation section is completed (see, for example, Figure 7(C)), the load weight calculation unit 62 estimates the weight of the soil and sand based on the torque around the foot pin due to the thrust of the boom 4 derived from the detection signal.

[0184] The excavator 100 may perform an opening / closing operation of the arm 5 (an operation of closing the arm 5 in the example of FIG. 7 ) along with the raising operation of the boom 4. For example, if a swing operation is performed with the arm 5 open after the boom raising operation, the distance from the upper swing structure 3 to the bucket 6 becomes longer (in other words, the swing radius becomes larger), and therefore the swing moment also becomes larger. As such, if a swing operation is performed with the arm 5 open, a large swing drive force is required and the swing time becomes longer. For this reason, when discharging excavated soil onto the ground, the swing operation after excavation is usually performed by closing the arm 5 to reduce the swing moment. On the other hand, when discharging excavated soil onto a dump truck, the swing operation is performed while further opening the arm 5 after excavation to avoid contact with the dump truck. In this way, even during the boom raising swing operation after excavation, the arm 5 is opened and closed depending on the work content. As a result, the moment associated with the opening and closing operation of the arm 5 is also applied to the boom 4.

[0185] The torque around the foot pin of the boom 4 due to the opening and closing operation of the arm 5 will be described with reference to Fig. 9. Fig. 9 is a schematic diagram of the attachment of the excavator 100 showing the relationship between the opening and closing operation of the arm 5 and the torque around the foot pin of the boom 4.

[0186] Here, the weight of soil loaded in the bucket 6 is defined as m. The distance from the connecting pin (the rotation center of the arm 5) between the boom 4 and the arm 5 to the center of gravity G1 of the soil is defined as r. The rotational angular velocity of the arm 5 is defined as ωa. The centrifugal force Fa caused by the opening and closing of the arm 5 can be expressed by the following equation (1).

[0187]

number

[0188] The horizontal distance from the foot pin of the boom 4 to the connecting pin between the boom 4 and the arm 5 is rx, and the vertical distance is rz. Furthermore, the horizontal component of the centrifugal force Fa is Fax, and the vertical component of the centrifugal force Fa is Faz. The torque τa (at least one of arm centrifugal force torque and arm inertia force torque, which will be described later) that occurs around the foot pin of the boom 4 due to the opening and closing of the arm 5 can be expressed by the following equation (2).

[0189]

number

[0190] In this way, when the arm 5 is opened or closed during boom raising, a torque τa is generated around the foot pin of the boom 4 due to the opening and closing of the arm 5. For this reason, a method for estimating the weight of soil and sand based on the torque around the foot pin during boom raising is required to appropriately compensate for the soil and sand weight.

[0191] 10 is a block diagram illustrating the processing of the load weight calculation unit 62. As shown in FIG. 10, the load weight calculation unit 62 has a torque calculation unit 71, an inertia force calculation unit 72, a centrifugal force calculation unit 73, an arm centrifugal force calculation unit 74, a stationary torque calculation unit 76, a weight conversion unit 77, and an inclination correction unit 78.

[0192] In this embodiment, the load weight calculation unit 62 calculates the weight of the soil and sand (load) loaded in the bucket 6 when the determination unit 61 determines that the conditions for detecting the weight of the soil and sand (load) loaded in the bucket 6 are met. In the process described below, when thrust from the boom cylinder 7 (measurements from the boom rod pressure sensor S7R and the boom bottom pressure sensor S7B) is applied, the weight of the soil and sand W1 is calculated based on the torque generated at the center of gravity of the soil with reference to the foot pin of the boom 4, etc. Note that this embodiment shows one method for calculating the weight of the soil and sand W1 based on the thrust and the center of gravity of the soil, and other methods may also be used.

[0193] The torque calculation unit 71 calculates the torque (detected torque) around the foot pin of the boom 4. The calculation is based on the pressure of the hydraulic oil in the boom cylinder 7 (boom rod pressure sensor S7R, boom bottom pressure sensor S7B).

[0194] The inertia force calculation unit 72 calculates the torque (inertia term torque) around the foot pin of the boom 4 due to the inertial force. The inertia term torque is calculated based on the angular acceleration around the foot pin of the boom 4 and the moment of inertia of the boom 4. The angular acceleration around the foot pin of the boom 4 and the moment of inertia are calculated based on the output of the attitude sensor.

[0195] In this embodiment, if the determination unit 61 determines that the angular acceleration around the foot pin of the boom 4 is small, the soil weight is calculated. When the inertia force calculation unit 72 calculates the inertia term torque when the angular acceleration around the foot pin of the boom 4 is small, the inertia term torque becomes a value close to zero. After completing excavation, the operator raises the boom 4 to the desired height so that the bucket 6 does not come into contact with the dump truck DT. Even if the operator performs a swing operation, the swing operation amount is smaller than the boom-raising operation amount. Thus, when the boom 4 is being raised, the swing operation of the upper swing body 3 is suppressed, or the swing operation is perceived as being very small. Therefore, no torque is generated due to the inertia force of the swing operation, or the effect of the torque due to the inertia force of the swing operation is perceived as being very small. Therefore, if the determination unit 61 determines that the angular acceleration around the foot pin of the boom 4 is small, the calculation of the inertia term torque by the inertia force calculation unit 72 may be omitted. In other words, the method for calculating the weight of soil and sand according to this embodiment can omit the influence of inertial force.

[0196] The centrifugal force calculation unit 73 calculates the torque (centrifugal torque) around the foot pin of the boom 4 due to Coriolis and centrifugal forces. The centrifugal torque is calculated based on the angular velocity of the boom 4 around the foot pin and the weight of the boom 4. The angular velocity of the boom 4 around the foot pin is calculated based on the output of the attitude sensor. The weight of the boom 4 is known.

[0197] The arm centrifugal force calculation unit 74 calculates the torque (torque τa of arm centrifugal force) around the foot pin of the boom 4 due to centrifugal force when the arm 5 is opened or closed. The torque τa of arm centrifugal force is calculated based on the output of the attitude sensor and the above-mentioned formulas (1) and (2).

[0198] Stationary torque calculation unit 76 calculates stationary torque τW, which is the torque around the foot pin of boom 4 when the attachment is stationary, based on the detected torque of torque calculation unit 71, the centrifugal term torque of centrifugal force calculation unit 73, and the arm centrifugal torque of arm centrifugal force calculation unit 74. Here, the equation for the torque around the foot pin (angle θ) of boom 4 is shown in equation (3). Note that τ on the left side of equation (3) represents the detected torque, the first term on the right side represents the inertia term torque (note that this term is assumed to be the moment of inertia J) (this term may be omitted if the determination unit 61 determines that the conditions for measuring the weight of the load are met), the second term on the right side represents the centrifugal term torque (note that the function h is a function used to calculate the centrifugal torque of boom 4), the third term on the right side represents the arm centrifugal force torque τa, and the fourth term on the right side represents the stationary torque τW.

[0199]

number

[0200] As shown in equation (3), the static torque τW can be calculated by subtracting the inertia term torque, the centrifugal term torque, and the arm centrifugal force torque τa from the detected torque τ. As a result, in this embodiment, it is possible to compensate for the influence caused by the rotational movement of the boom or the like around the pin. For example, as shown in FIG. 9, if the closing movement of the arm 5 occurs during the boom raising movement, the opening and closing movement of the arm 5 generates a torque τa of the arm centrifugal force around the foot pin of the boom 4 in the boom raising direction. Therefore, the torque calculated by the torque calculation unit 71 is smaller than when the closing movement of the arm 5 does not occur. In this embodiment, the load weight calculation unit 62 can accurately calculate the static torque τW by compensating with the torque τa of the arm centrifugal force calculated by the arm centrifugal force calculation unit 74.

[0201] The weight conversion unit 77 calculates the weight of soil W1 based on the static torque τW compensated for by the torque τa of the arm centrifugal force. The weight of soil W1 can be calculated, for example, by subtracting the torque when no soil is loaded in the bucket 6 from the static torque τW and dividing the result by the horizontal distance from the foot pin of the boom 4 to the center of gravity of the soil.

[0202] The tilt correction unit 78 performs correction based on the attitude of the shovel 100. When the shovel 100 is on an inclined surface with a pitch angle θp, the attitude of the attachment at a boom angle θ1 is equal to the attitude of the attachment at a boom angle (θ1 + θp) when the shovel 100 is on a flat surface. In other words, by correcting the detected boom angle θ1 with the pitch angle θp, the soil weight W1 can be corrected based on the attitude of the shovel 100.

[0203] Furthermore, when the excavator 100 is on an inclined surface with a roll angle θr, the thrust F of the boom cylinder 7 has a vertical component and a horizontal component when the excavator 100 is viewed from the front. Therefore, by correcting the thrust F of the boom cylinder 7 with the roll angle θr, that is, by making the vertical component Fcosθr, the weight of the soil and sand can be corrected according to the attitude of the excavator 100.

[0204] 11 is another block diagram illustrating the processing of the load weight calculation unit 62. As shown in FIG. 11, the load weight calculation unit 62 has a torque calculation unit 71, an inertia force calculation unit 72, a centrifugal force calculation unit 73, an arm inertia force calculation unit 75, a stationary torque calculation unit 76, a weight conversion unit 77, and an inclination correction unit 78.

[0205] The torque calculation unit 71 calculates the torque (detected torque) around the foot pin of the boom 4. The inertia force calculation unit 72 calculates the torque (inertia term torque) around the foot pin of the boom 4 due to inertial force. The centrifugal force calculation unit 73 calculates the torque (centrifugal term torque) around the foot pin of the boom 4 due to Coriolis and centrifugal force. The torque calculation unit 71, inertia force calculation unit 72, and centrifugal force calculation unit 73 are similar to the torque calculation unit 71, inertia force calculation unit 72, and centrifugal force calculation unit 73 of the load weight calculation unit 62 shown in FIG. 10, and therefore a duplicated description will be omitted.

[0206] The arm inertia force calculation unit 75 calculates the torque (arm inertia force torque) around the foot pin of the boom 4 due to acceleration / deceleration (inertia force) of opening and closing the arm 5. The arm inertia force torque is calculated based on the output of the attitude sensor.

[0207] Stationary torque calculation section 76 calculates stationary torque τW, which is the torque around the foot pin of boom 4 when the attachment is stationary, based on the detected torque of torque calculation section 71, the inertia term torque of inertia force calculation section 72, the centrifugal term torque of centrifugal force calculation section 73, and the arm inertia force torque of arm inertia force calculation section 75. Here, the equation for the torque around the foot pin of boom 4 is the same as equation (3) described above. Note that in this example, the third term on the right-hand side of equation (3) represents the arm inertia force torque τa.

[0208] As shown in equation (3), the static torque τW can be calculated by subtracting the inertia term torque, the centrifugal term torque, and the arm inertia force torque τa from the detected torque τ. This allows the present embodiment to compensate for the influence of the rotational movement of the boom or the like around the pin. For example, as shown in FIG. 9 , if the closing movement of the arm 5 occurs during the boom raising movement, the opening and closing movement of the arm 5 generates an arm inertia force torque τa around the foot pin of the boom 4. Therefore, the torque calculated by the torque calculation unit 71 changes compared to when the closing movement of the arm 5 does not occur. In particular, when the weight of soil transported by the bucket 6 is heavy, the influence of the inertia force becomes greater when the bucket 6 is moved from a position far from the excavator 100 to a position closer to the excavator 100. In the load weight calculation unit 62 of this embodiment, the static torque τW can be calculated accurately by compensating with the arm inertia force torque τa calculated by the arm inertia force calculation unit 75.

[0209] The weight conversion unit 77 calculates the weight of soil W1 based on the static torque τW compensated for by the torque τa of the arm inertia force. The tilt correction unit 78 performs correction based on the posture of the shovel 100. The weight conversion unit 77 and tilt correction unit 78 are the same as the weight conversion unit 77 and tilt correction unit shown in Fig. 10, and therefore a duplicated description will be omitted.

[0210] [Load weight determination process] Next, an example of the load weight determination process will be described with reference to Fig. 12. Fig. 12 is a flowchart showing an example of the load weight determination process.

[0211] In step S1, the excavator 100 excavates earth and sand with the bucket 6 and starts a boom raising operation. When the height of the bucket 6 reaches the bottom end of the measurement range, the load weight calculation unit 62 of the controller 30 starts calculating the weight of the earth and sand loaded in the bucket 6.

[0212] In step S2, the determination unit 61 of the controller 30 determines whether the boom cylinder 7 has reached the cushion area. Specifically, the determination unit 61 determines whether the detection signal related to the raising operation of the boom 4 satisfies a first condition related to the cushion function of the boom cylinder 7.

[0213] If it is determined that the boom cylinder 7 has reached the cushion area (YES), the determination unit 61 proceeds to step S3. On the other hand, if it is determined that the boom cylinder 7 has not reached the cushion area (NO), the determination unit 61 proceeds to step S4.

[0214] In step S3, the determination unit 61 of the controller 30 determines that the determination condition is met. The determination unit 61 also determines that the measurement accuracy of the soil weight is low. The determination unit 61 notifies the load weight calculation unit 62 and the information transmission unit 53 that the determination condition is met.

[0215] The load weight calculation unit 62 determines the weight of the soil and sand in response to the notification from the determination unit 61. In response to the notification from the determination unit 61, the information transmission unit 53 displays the measurement accuracy determined by the determination unit 61 and the soil and sand weight calculated by the load weight calculation unit 62 on the display device 40.

[0216] In step S4, the determination unit 61 of the controller 30 determines whether the boom raising operation has stopped. Specifically, the determination unit 61 determines whether the detection signal related to the raising operation of the boom 4 satisfies a second condition related to the boom raising operation.

[0217] If it is determined that the boom raising operation has stopped (YES), the determination unit 61 proceeds to step S5. On the other hand, if it is determined that the boom raising operation has not stopped (NO), the determination unit 61 proceeds to step S7.

[0218] In step S5, the determination unit 61 of the controller 30 determines whether the boom raising amount is sufficient. Specifically, the determination unit 61 determines whether the detection signal related to the raising operation of the boom 4 satisfies a fourth condition related to the raising amount of the boom 4.

[0219] If it is determined that the boom lifting amount is sufficient (YES), the determination unit 61 proceeds to step S6. On the other hand, if it is determined that the boom lifting amount is insufficient (NO), the determination unit 61 proceeds to step S3.

[0220] In step S6, the determination unit 61 of the controller 30 determines that the determination condition is met. The determination unit 61 also determines that the measurement accuracy of the soil weight is medium. The determination unit 61 notifies the load weight calculation unit 62 and the information transmission unit 53 that the determination condition is met.

[0221] The load weight calculation unit 62 determines the weight of the soil and sand in response to the notification from the determination unit 61. In response to the notification from the determination unit 61, the information transmission unit 53 displays the measurement accuracy determined by the determination unit 61 and the soil and sand weight calculated by the load weight calculation unit 62 on the display device 40.

[0222] In step S7, determination unit 61 of controller 30 determines whether bucket 6 has risen to a predetermined height. Specifically, determination unit 61 determines whether the detection signal related to the raising operation of boom 4 satisfies a third condition related to the height of bucket 6.

[0223] If it is determined that the bucket 6 has risen to the predetermined height (YES), the determination unit 61 proceeds to step S6. On the other hand, if it is determined that the bucket 6 has not risen to the predetermined height (NO), the determination unit 61 proceeds to step S8.

[0224] In step S8, the determination unit 61 of the controller 30 determines whether the acceleration of the boom 4 is within a predetermined range. Specifically, the determination unit 61 determines whether the detection signal related to the raising operation of the boom 4 satisfies a fifth condition related to the acceleration at which the boom 4 moves.

[0225] If it is determined that the acceleration of the boom 4 is within the predetermined range (YES), the determination unit 61 proceeds to step S9. On the other hand, if it is determined that the acceleration of the boom 4 is not within the predetermined range (NO), the determination unit 61 returns the process to step S2.

[0226] In step S9, the determination unit 61 of the controller 30 determines that the determination condition is met. The determination unit 61 also determines that the measurement accuracy of the soil weight is high. The determination unit 61 notifies the load weight calculation unit 62 and the information transmission unit 53 that the determination condition is met.

[0227] The load weight calculation unit 62 determines the weight of the soil and sand in response to the notification from the determination unit 61. In response to the notification from the determination unit 61, the information transmission unit 53 displays the measurement accuracy determined by the determination unit 61 and the soil and sand weight calculated by the load weight calculation unit 62 on the display device 40.

[0228] [Screen display] In this embodiment, measurement of the weight of soil loaded in the bucket 6 begins when the bucket 6 reaches the measurement section in response to the operator's operation of raising the boom 4. Then, when a detection signal related to the raising operation of the boom 4 satisfies a predetermined confirmation condition, the measured soil weight is confirmed and its measurement accuracy is determined. For this reason, it is preferable that the operator be able to recognize the confirmed soil weight and its measurement accuracy. Therefore, the information transmission unit 53 displays a display screen on which the confirmed soil weight and measurement accuracy can be recognized.

[0229] Fig. 13 is a diagram showing an example of a main screen displayed on a display device. A main screen 41V shown in Fig. 13 displays a date and time display area 411, a rotation speed mode display area 412, a driving mode display area 413, an attachment display area 414, an engine control status display area 415, a urea water remaining amount display area 416, a fuel remaining amount display area 417, a hydraulic oil temperature display area 418, an engine operating time display area 419, a camera image display area 420, and a soil and sand weight display area 430.

[0230] Specifically, the date and time display area 411 is an area that displays the current date and time. The rotation speed mode display area 412 is an area that displays the current rotation speed mode set by the engine rotation speed adjustment dial. The travel mode display area 413 is an area that displays the current travel mode. The attachment display area 414 is an area that displays an image that represents the currently attached end attachment. Figure 13 shows a state in which an image that represents the bucket 6 is displayed.

[0231] The engine control status display area 415 is an area that displays the control status of the engine 11. The urea water remaining amount display area 416 is an area that displays the remaining amount of urea water stored in the urea water tank. The fuel remaining amount display area 417 is an area that displays the remaining amount of fuel stored in the fuel tank. The hydraulic oil temperature display area 418 is an area that displays the temperature state of the hydraulic oil in the hydraulic oil tank. The engine operating time display area 419 is an area that displays the accumulated operating time of the engine 11.

[0232] The camera image display area 420 is an area that displays an image captured by the imaging device S6 together with an icon 421 of the shovel 100. In the example of FIG. 13, the camera image display area 420 displays an image captured by the rear camera S6B. The image captured by the rear camera S6B is a rear image that shows the space behind the shovel 100. This allows the operator to check what is behind the shovel 100. Furthermore, the icon 421 displays an image 421a showing the shovel 100 as well as an image 421b showing the range captured by the rear camera S6B.

[0233] The soil weight display area 430 is an area for communicating to the operator the weight of soil and sand loaded in the bucket 6 and the measurement accuracy of the soil weight. The soil weight display area 430 displays soil weight history information 431. The soil weight history information 431 correlates and displays the number of excavation operations performed, the soil weight determined during each excavation operation, and the measurement accuracy determined when the soil weight was determined. The soil weight history information 431 displays the soil weight and measurement accuracy for each excavation operation in chronological order.

[0234] The sediment weight display area 430 may highlight low-accuracy sediment weights. As an example, the sediment weight display area 430 may display low-accuracy sediment weights in a different text color or background color (e.g., red). The sediment weight display area 430 may also display an icon or the like near the low-accuracy sediment weight. Furthermore, when displaying a low-accuracy sediment weight on the display device 40, the information transmission unit 53 may notify the user that the sediment weight has been determined to be low-accuracy by providing auditory information via the audio output device 43. When displaying a low-accuracy sediment weight, the sediment weight display area 430 may display a message or icon prompting the user to remeasure.

[0235] The operator can recognize the total weight of the soil loaded onto the bed of the dump truck by referring to the soil weight display area 430. The operator can also recognize how reliable the soil weight is by referring to the measurement accuracy in the soil weight display area 430. Furthermore, if the operator recognizes by referring to the soil weight display area 430 that the soil weight is low in accuracy, the operator can release the soil loaded in the bucket 6 without loading it onto the dump truck, and perform the excavation operation again to remeasure the soil weight.

[0236] The above describes embodiments of the shovel 100, but the present invention is not limited to the above embodiments, and various modifications and improvements are possible within the scope of the gist of the present invention described in the claims.

[0237] Although it has been explained that the load weight calculation unit 62 shown in Fig. 10 compensates for the torque due to the centrifugal force caused by the opening and closing of the arm 5, and the load weight calculation unit 62 shown in Fig. 11 compensates for the torque due to the inertial force caused by the opening and closing of the arm 5, this is not limited to this. The load weight calculation unit 62 may be configured to perform compensation based on at least one of the torque due to the centrifugal force caused by the opening and closing of the arm 5 and the torque due to the inertial force caused by the opening and closing of the arm 5.

[0238] That is, a configuration may be adopted in which both the torque due to the centrifugal force caused by the opening and closing of the arm 5 and the torque due to the inertia force caused by the opening and closing of the arm 5 are compensated for. In this case, the load weight calculation unit 62 may include a torque calculation unit 71, an inertia force calculation unit 72, a centrifugal force calculation unit 73, an arm centrifugal force calculation unit 74, an arm inertia force calculation unit 75, a stationary torque calculation unit 76, a weight conversion unit 77, and an inclination correction unit 78. In this case, the stationary torque calculation unit 76 calculates a stationary torque τW, which is the torque around the foot pin of the boom 4 when the attachment is stationary, based on the detected torque of the torque calculation unit 71, the inertia term torque of the inertia force calculation unit 72, the centrifugal term torque of the centrifugal force calculation unit 73, the arm centrifugal force torque of the arm centrifugal force calculation unit 74, and the arm inertia force torque of the arm inertia force calculation unit 75. Furthermore, the torque τa in the above-described equation (3) may be a torque that combines the arm centrifugal force torque and the arm inertia force torque. This makes it possible to further improve the accuracy of detecting the weight of soil and sand.

[0239] In this embodiment, an example of performing measurements when the height of the bucket 6 is included in the measurement range will be described, but this is not limited to a method of performing measurements when the height is included in the measurement range, and any measurement can be performed while the attachment is being raised.

[0240] The shovel (working machine) 100 according to this embodiment is equipped with a bucket 6 as an end attachment, and measures the weight of soil (carried object) transported by the bucket 6. The method for measuring the weight of soil and sand applied to the shovel (working machine) 100 according to this embodiment may also be applied to other working machines. That is, the method for measuring the weight of soil and sand applied to the shovel 100 according to this embodiment may also be applied to working machines having end attachments used when transporting objects, such as a bucket, a lifting magnet, a grapple, a fork, or a harvester including a chainsaw. This embodiment does not limit the working machine to the shovel 100, and may be, for example, a construction machine, a forestry machine, or a transport machine with an attachment.

[0241] (Variation 1) In the above-described embodiment, an example has been described in which a bucket 6 is provided at the tip of the attachment of the shovel 100. However, the above-described embodiment does not limit the tip of the attachment to the bucket 6. Therefore, as a modified example, a lifting magnet may be provided at the tip of the attachment of the work machine. Note that the lifting magnet provided at the tip of the attachment can be driven by the bucket cylinder 9. Furthermore, not limited to a lifting magnet, even if another end attachment is provided at the tip of the attachment, it can be driven by the bucket cylinder 9 in the same way.

[0242] In this modified example, a measurable area (hereinafter referred to as the measurement zone) is set according to the height of the lifting magnet to measure the weight of scrap iron and other materials attracted to the lifting magnet. The measurement zone in this modified example is set at a height that minimizes the effect of the magnetic force from the lifting magnet on the pile of scrap iron. For example, the measurement zone is set so that the distance from the top of the pile of scrap iron to the bottom of the scrap iron attracted to the lifting magnet is 1.5 m or more. This makes it possible to minimize weight measurement errors caused by magnetic force.

[0243] The conditions for determining the weight of the load by the determining unit 61 according to this modification are the same as those in the above-described embodiment, and therefore a description thereof will be omitted.

[0244] In this modified example, the work machine performs the above-mentioned control, thereby achieving the same effect as the above-mentioned embodiment, and also realizing improved accuracy in measuring the weight of iron scraps, etc., even when using a lifting magnet.

[0245] (Variation 2) In the above-described embodiment, an example has been described in which the bucket 6 is provided at the tip of the attachment of the shovel 100. In the above-described first modification, an example has been described in which a lifting magnet is provided at the tip of the attachment of the shovel 100. However, the end attachment of the shovel 100 is not limited to the bucket 6 or the lifting magnet, and a tilt bucket may be provided.

[0246] The bucket 6 can rotate in the front-rear direction, but is not provided with a mechanism for rotating it left-right. In contrast, the tilt bucket is provided with a mechanism for rotating it both forward and backward, as well as left-right. As a result, when the excavator 100 is provided with a tilt bucket, it can perform excavation operations and the like while tilted left and right.

[0247] When the excavation operation is completed and the tilt bucket has moved upward a predetermined distance, the controller 30 releases (deactivates) the control of tilt in the left and right directions and performs control so that the tip of the tilt bucket (for example, the toe line of the tilt bucket) becomes horizontal. This control prevents the soil from spilling out of the tilt bucket when the tilt bucket scoops up soil, for example.

[0248] In this modified example, a measurable area (hereinafter referred to as a measurement section) is set according to the height of the tilt bucket in order to measure the weight of earth and sand (an example of a load) loaded in the tilt bucket. The measurement section according to this modified example is set, for example, after the tip of the tilt bucket (for example, the tip of the tilt bucket) has been controlled to be horizontal, that is, above the above-mentioned predetermined distance.

[0249] The conditions for determining the weight of the load by the determination unit 61 according to this modification may be the same as those in the above-described embodiment. Furthermore, the predetermined conditions for measuring the weight of the load by the determination unit 61 may include whether the angular acceleration in the left-right direction of the attachment including the tilt bucket is lower than a predetermined threshold. A well-known detection device may be used as the sensor for detecting the angular acceleration in the left-right direction.

[0250] In this modified example, the work machine performs the above-described control, thereby achieving the same effects as the above-described embodiment, and also achieving improved accuracy in measuring the weight of soil and sand even when using a tilt bucket.

[0251] (Variation 3) In the above-described embodiment, the bucket 6 is provided at the tip of the attachment of the shovel 100, and the process of determining the weight of a load such as earth and sand loaded in the bucket 6 has been described. However, the above-described embodiment is not limited to determining the weight of an object loaded on an end attachment. The above-described embodiment can be applied to determining the weight of an object held by an end attachment.

[0252] For example, the above-described embodiments may be used in a process in which a lifting magnet is provided at the tip of the attachment and the weight of scrap iron or the like attracted to the lifting magnet is determined. For example, the above-described embodiments may be used in a process in which a hook is provided at the tip of the attachment and the weight of a load or the like suspended from the hook is determined. For example, the above-described embodiments may be used in a process in which a grapple is provided at the tip of the attachment and the weight of lumber or the like gripped by the grapple is determined. In other words, the object held by the end attachment may include an object loaded in a bucket, an object hung from a hook, an object attracted to a lifting magnet, an object gripped by a grapple, or the like.

[0253] <Effects> The controller 30 of the shovel 100 according to this embodiment detects the weight of an object held by the implement if one or more of a plurality of conditions are met. Depending on the operation or environment of the shovel 100, certain conditions may not be met, leading to an oversight of the object's weight being detected. The controller 30 according to this embodiment determines the weight of the object if any of the conditions defined from various perspectives is met, thereby reducing the oversight of the weight of the held object being detected.

[0254] The plurality of conditions may include a condition related to the operation of the attachment. For example, when loading earth and sand onto a dump truck, there is always a timing when the boom raising operation must be stopped, and therefore, the controller 30 according to this embodiment can reduce the number of times that the weight of the object is not detected.

[0255] The controller 30 of the shovel 100 may determine whether or not the conditions related to the operation of the attachment are satisfied based on the pilot pressure or the operation signal of the electric lever. The controller 30 according to this embodiment can reduce the failure to detect the weight of an object, whether the shovel 100 employs a hydraulic operation system or an electric operation system.

[0256] The multiple conditions may include conditions related to the cushioning function of the cylinder that operates the attachment, the height of the work tool, the lift amount of the attachment, or the acceleration at which the attachment moves. The controller 30 according to this embodiment determines whether the weight of the object can be determined by combining various conditions related to the operation of the attachment, and therefore can reduce the risk of missing an object's weight even in operations or environments that do not satisfy certain conditions.

[0257] The controller 30 of the shovel 100 may determine the accuracy of the conditions satisfied by the detection information and display information related to the determined accuracy on the display device. The controller 30 according to this embodiment allows the operator to recognize the measurement accuracy of the measured weight of the object, and therefore, for example, allows the operator to remeasure the weight of the object if the weight of the object is found to be low in accuracy.

[0258] The controller 30 of the shovel 100 may determine the measurement accuracy as high when the detection information satisfies a condition related to acceleration, determine the measurement accuracy as medium when the detection information satisfies a condition related to the height of the work tool, the lift amount of the attachment, or the operation of the attachment, and may determine the measurement accuracy as low when the detection information satisfies a condition related to the cushioning function. The controller 30 according to this embodiment can appropriately determine the measurement accuracy depending on the contents of the conditions satisfied by the detection information.

[0259] While the embodiments of the work machine according to the present invention have been described above, the present invention is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These changes also naturally fall within the technical scope of the present invention. [Explanation of symbols]

[0260] 100 Shovel 1 Undercarriage 2. Swivel mechanism 2A hydraulic swing motor 3 Upper rotating body 4 Boom (attachment) 5 Arm (attachment) 6 Bucket (attachment) 7 Boom cylinder 8 Arm Cylinder 9 Bucket cylinder 21,22 Oil pressure sensor 30 Controller (control device) 40 Display device 42 Input Devices 43 Audio output device 47 Storage device 51 Position calculation section 52 Distance calculation unit 53 Information Transmission Department 54 Control Unit 55 Turning angle calculation unit 60 Sediment load processing section 61 Judgment section 62 Load weight calculation unit 63 Maximum load detector 64 Added load calculation unit 65 Remaining load calculation unit 71 Torque calculation unit 72 Inertia force calculation section 73 Centrifugal force calculation unit 74 Arm centrifugal force calculation unit 75 Arm inertia force calculation unit 76 Stationary torque calculation section 77 Weight conversion section 78 Tilt correction unit S1 Boom Angle Sensor S2 Arm Angle Sensor S3 Bucket Angle Sensor S4 aircraft tilt sensor S5 Turning status sensor S6 imaging device S7R Boom Rod Pressure Sensor S7B Boom Bottom Pressure Sensor S7C Boom cylinder stroke sensor S8R Arm rod pressure sensor S8B Arm bottom pressure sensor S8C Arm cylinder stroke sensor S9R Bucket rod pressure sensor S9B Bucket Bottom Pressure Sensor S9C Bucket Cylinder Stroke Sensor

Claims

1. a control unit configured to control a work machine having a work machine body, an attachment attached to the work machine body, and a work implement provided at the tip of the attachment, the control unit is configured to, after holding an object on the work tool, determine whether detection information related to the lifting operation of the attachment satisfies a plurality of conditions, and, if one or more of the plurality of conditions are satisfied, detect the weight of the object based on the detection information. Control device for work machine.

2. the plurality of conditions include a condition related to operation of the attachment; The control device for a work machine according to claim 1.

3. The control unit determines whether a condition related to the operation of the attachment is satisfied based on a pilot pressure or an operation signal of an electric lever. The control device for a work machine according to claim 2.

4. the plurality of conditions further includes a condition regarding a cushioning function of a cylinder that operates the attachment; The control device for a work machine according to claim 2.

5. The plurality of conditions further includes a condition regarding the height of the work tool or the lifting amount of the attachment. The control device for a work machine according to claim 4.

6. The plurality of conditions further includes a condition related to the acceleration at which the attachment moves. The control device for a work machine according to claim 5.

7. the control unit determines the accuracy of the weight based on the condition satisfied by the detection information, and displays information about the determined accuracy on a display device. The control device for a work machine according to claim 6.

8. The control unit determining that the detection information is highly accurate when the detection information satisfies the condition regarding the acceleration; determining the detection information to be of medium accuracy when the detection information satisfies a condition related to the height of the work tool, the lift amount of the attachment, or the operation of the attachment; determining that the detection information is of low accuracy when the detection information satisfies a condition related to the cushioning function; The control device for a work machine according to claim 7.

9. a control unit configured to control a work machine having a work machine body, an attachment attached to the work machine body, and a work implement provided at the tip of the attachment, the control unit is configured to detect a weight of the object based on detection information regarding a lifting operation of the attachment after the object is held by the work tool, when the detection information regarding the lifting operation of the attachment satisfies a condition regarding operation of the attachment. Control device for work machine.

Images