Work machinery, control devices for work machinery

Abstract

This can improve the accuracy of measuring the weight of objects. [Solution] A work machine having an attachment mounted on the main body of the work machine and a work tool provided at the tip of the attachment, wherein after an object is held in the work tool, a control unit is provided that, based on detection information relating to the lifting operation of the attachment, determines that the piston member of the cylinder that operates the attachment has reached a range in which the cushioning function acts, and then determines that the measurement result of the weight of the object held in the work tool is obtained differently depending on the state of the work machine at the time the determination is made.

Description

Technical Field

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[0001] The present invention relates to a work machine and a control device for a work machine.

Background Art

[0002] Conventionally, when measuring the weight of an object such as earth and sand loaded from a shovel onto the bed of a dump truck or the like, a technique for suppressing fluctuations in the weight measurement result due to disturbances is known. Specifically, for example, conventionally, based on at least either the centrifugal force of the arm or the inertial force of the arm, the torque for rotating the boom is compensated, and based on the compensated torque, a technique for measuring the weight of the conveyed material carried by the attachment is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described conventional technology, the centrifugal force of the arm and the inertial force of the arm are regarded as disturbances that cause fluctuations in the measurement result of the weight of the object, but there are other disturbances that cause fluctuations in the measurement result of the weight of the object.

[0005] The disclosed technology has been made in view of the above circumstances, and an object thereof is to improve the measurement accuracy of the weight of an object.

Means for Solving the Problems

[0006] An embodiment of the present invention is a work machine having an attachment mounted on a work machine body and a work tool provided at the tip of the attachment, wherein, after an object is held in the work tool, a control unit is provided that, based on detection information relating to the lifting operation of the attachment, determines that the piston member of the cylinder that operates the attachment has reached a predetermined range, and the control unit determines that the measurement result of the weight of the object obtained differs according to the state of the work machine at the time the determination is made.

[0007] An embodiment of the present invention is a work machine comprising an attachment mounted on a work machine body and a work tool provided at the tip of the attachment, wherein, after an object is held in the work tool, a control unit is provided that, based on detection information relating to the lifting operation of the attachment, determines that the piston member of the cylinder that operates the attachment has reached a predetermined range, and the control unit determines that the measurement result of the weight of the object obtained differs according to the state of the work machine at the time the determination is made, and the state of the work machine at the time the determination is made is after the lifting operation of the attachment has started, and the object If the weight measurement result has not been obtained, the weight of the object calculated based on the detection information related to the lifting operation of the attachment at the time the determination is made is obtained as the measurement result. If the state of the work machine at the time the determination is made is after the lifting operation of the attachment has started and the weight measurement result of the object has been obtained, the obtained measurement result is obtained as the weight measurement result of the object at the time the determination is made. If the state of the work machine at the time the determination is made is the state at the start of the lifting operation of the attachment, the measurement result is not obtained.

[0008] A control device for a work machine according to an embodiment of the present invention is a control device for a work machine having an attachment mounted on the body of the work machine and a work tool provided at the tip of the attachment, wherein the control device has a control unit that, after an object has been held in the work tool, determines, based on detection information relating to the lifting operation of the attachment, that the piston member of the cylinder that operates the attachment has reached a predetermined range, and then determines that the measurement result of the weight of the object obtained differs according to the state of the work machine at the time the determination is made. [Effects of the Invention]

[0009] This can improve the accuracy of measuring the weight of objects. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view of a shovel used as an excavator according to this embodiment. [Figure 2] This diagram schematically shows an example of the configuration of the drive system of the excavator according to this embodiment. [Figure 3] This figure schematically shows an example of the configuration of the hydraulic system of the excavator according to this embodiment. [Figure 4] This figure schematically shows an example of the components related to the operating system of the hydraulic system of the excavator according to this embodiment. [Figure 5] This figure shows an example of the configuration of the electric control system for the excavator according to this embodiment. [Figure 6] This figure schematically shows an example of a component related to the soil load detection function of the shovel according to this embodiment. [Figure 7] This diagram illustrates the excavation and loading operations of an excavator. [Figure 8] This flowchart shows an example of the process for determining the weight of the cargo. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. Furthermore, the embodiments described below are illustrative and not limiting to the invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. In addition, identical or corresponding components in each drawing are denoted by the same or corresponding reference numerals, and their descriptions may be omitted.

[0012] [Shovel Overview] First, an overview of the shovel (working machine) 100 according to this embodiment will be described with reference to Figure 1. Figure 1 is a side view of the shovel as an excavator according to this embodiment.

[0013] In Figure 1, the shovel 100 is positioned on a horizontal plane facing the uphill slope ES of the construction target, and the uphill slope BS (i.e., the shape of the slope after construction relative to the uphill slope ES), which is an example of the target construction surface described later, is also shown. The uphill slope ES of the construction target is provided with a cylindrical body (not shown) that indicates the direction normal to the uphill slope BS, which is the target construction surface.

[0014] The excavator 100 according to this embodiment comprises a lower traveling body 1, an upper rotating body 3 mounted on the lower traveling body 1 so as to be rotatable via a slewing mechanism 2, a boom 4, an arm 5, and a bucket 6 that constitute an attachment (working equipment), and a cabin 10. The lower traveling body 1 and the upper rotating body 3 constitute the main body of the working machine.

[0015] The lower travel body 1 moves the shovel 100 by hydraulically driving a pair of left and right crawlers with travel hydraulic motors 1L and 1R (see Figure 2, described later). In other words, the pair of travel hydraulic motors 1L and 1R (an example of travel motors) drive the lower travel body 1 (crawlers) as the driven part.

[0016] The upper rotating body 3 rotates relative to the lower traveling body 1 when driven by the rotating hydraulic motor 2A (see Figure 2, described later). In other words, the rotating hydraulic motor 2A is a rotating drive unit that drives the upper rotating body 3 as the driven part, and can change the orientation of the upper rotating body 3.

[0017] Incidentally, the upper revolving body 3 may be electrically driven by an electric motor (hereinafter referred to as "revolving electric motor") instead of the revolving hydraulic motor 2A. That is, the revolving electric motor is a revolving drive unit that drives the upper revolving body 3 as a non-driven part, similar to the revolving hydraulic motor 2A, and can change the orientation of the upper revolving body 3.

[0018] The boom 4 is pivotally attached to the center of the front part of the upper revolving body 3 so as to be able to pitch. An arm 5 is pivotally attached to the tip of the boom 4 so as to be able to rotate vertically, and a bucket 6 as an end attachment is pivotally attached to the tip of the arm 5 so as to be able to rotate vertically. The boom 4, the arm 5, and the bucket 6 are respectively hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 as hydraulic actuators.

[0019] Incidentally, the bucket 6 is an example of an end attachment. At the tip of the arm 5, depending on the work content and the like, instead of the bucket 6, other end attachments, for example, a bucket for slope, a bucket for dredging, a breaker, a lifting magnet, a grapple, a fork, a harvester including a chainsaw, etc. may be attached.

[0020] The cab 10 is a driver's cab in which an operator rides and is mounted on the left side of the front part of the upper revolving body 3.

[0021] [Configuration of Excavator] Next, in addition to FIG. 1, referring to FIG. 2, the specific configuration of the excavator 100 according to the present embodiment will be described. FIG. 2 is a diagram schematically showing an example of the configuration of the drive system of the excavator according to the present embodiment. In FIG. 2, the mechanical power system, the hydraulic oil line, the pilot line, and the electric control system are respectively shown by double lines, solid lines, broken lines, and dotted lines.

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

[0023] The engine 11 is the main power source in the hydraulic drive system and is mounted, for example, at the rear of the upper slewing body 3. Specifically, the engine 11 rotates at a constant speed at a preset target speed under direct or indirect control by the 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 light oil as fuel.

[0024] The regulator 13 controls the discharge rate 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 later.

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

[0026] The control valve 17 is a hydraulic control device that is mounted, for example, in the center of the upper slewing body 3 and controls the hydraulic drive system in response to the operator's operation of the operating 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 fluid from the main pump 14 to the hydraulic actuators (travel hydraulic motors 1L, 1R, slewing hydraulic motor 2A, boom cylinder 7, arm cylinder 8, and bucket cylinder 9) according to the operating state of the operating device 26. Specifically, the control valve 17 includes control valves 171 to 176 that control the flow rate and direction of the hydraulic fluid supplied from the main pump 14 to each of the hydraulic actuators. More specifically, control valve 171 corresponds to the travel hydraulic motor 1L, control valve 172 corresponds to the travel hydraulic motor 1R, and control valve 173 corresponds to the slewing hydraulic motor 2A. Also, control valve 174 corresponds to the bucket cylinder 9, control valve 175 corresponds to the boom cylinder 7, and control valve 176 corresponds to the arm cylinder 8. Furthermore, control valve 175 includes, for example, control valves 175L and 175R, as described later, and control valve 176 includes, for example, control valves 176L and 176R, as described later. Details of control valves 171 to 176 will be described later.

[0027] The operating system of the shovel 100 according to this embodiment includes a pilot pump 15 and an operating device 26. The operating system of the shovel 100 also includes a shuttle valve 32 as part of the machine control function by the controller 30, which will be described later.

[0028] The pilot pump 15 is mounted, for example, at 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.

[0029] The control device (an example of an operating unit) 26 is located near the cockpit of the cabin 10. The control device 26 is an input means for the operator to operate various operating elements (lower traveling body 1, upper slewing body 3, boom 4, arm 5, bucket 6, etc.). In other words, the control device 26 is an input means for the operator to operate the hydraulic actuators that drive each of the operating elements (i.e., the traveling hydraulic motors 1L, 1R, the slewing hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, etc.).

[0030] The operating device 26 is connected to the control valve 17 either directly through the secondary pilot line or indirectly through the shuttle valve 32 (described later) located on the secondary pilot line. As a result, pilot pressure corresponding to the operating state of the lower traveling body 1, upper slewing body 3, boom 4, arm 5, and bucket 6 in the operating device 26 can be input to the control valve 17. Therefore, the control valve 17 can drive each hydraulic actuator according to the operating state of the operating device 26.

[0031] The operating device 26 includes, for example, a lever device for operating the arm 5 (arm cylinder 8). The operating device 26 also includes, for example, lever devices 26A to 26C for operating the boom 4 (boom cylinder 7), bucket 6 (bucket cylinder 9), and upper slewing body 3 (slewing hydraulic motor 2A) respectively (see Figure 4). Furthermore, the operating device 26 includes, for example, lever devices and pedal devices for operating the left and right pairs of crawlers (travel hydraulic motors 1L, 1R) of the lower traveling body 1.

[0032] The shuttle valve 32 has two inlet ports and one outlet port. The shuttle valve 32 outputs hydraulic fluid with the higher 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 Figure 4 for details). Therefore, the shuttle valve 32 can apply the higher of the pilot pressure generated by the operating device 26 and the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve. In other words, the controller 30, described later, can control the corresponding control valve and control the operation of various operating elements by outputting a pilot pressure from the proportional valve 31 that is higher than the secondary pilot pressure output from the operating device 26, regardless of the operator's operation of the operating device 26. The shuttle valve 32 includes, for example, shuttle valves 32AL, 32AR, 32BL, 32BR, 32CL, and 32CR, as described below.

[0033] The control system of the shovel 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 storage device 47, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine tilt sensor S4, a slewing state sensor S5, an imaging device S6, a positioning device P1, and a communication device T1.

[0034] The controller 30 (an example of a control device) is installed, for example, inside the cabin 10 and controls the drive of the shovel 100. The functions of the controller 30 may be realized by any hardware, software, or a combination thereof. For example, the controller 30 is mainly composed of a microcomputer including a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), non-volatile auxiliary storage device, and various input / output interfaces. The controller 30 realizes various functions by executing various programs stored in the ROM or non-volatile auxiliary storage device on the CPU.

[0035] For example, the controller 30 sets a target rotational speed based on a predetermined work mode set by an operator or other predetermined operation, and performs drive control to keep the engine 11 rotating at a constant speed. Also, for example, the controller 30 outputs a control command to the regulator 13 as needed to change the discharge amount of the main pump 14.

[0036] Furthermore, for example, the controller 30 performs control related to a machine guidance function that guides the manual operation of the shovel 100 by the operator through the operating device 26. The controller 30 also performs control related to a machine control function that automatically assists the manual operation of the shovel 100 by the operator through the operating device 26. 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. The controller 30 also includes a soil load processing unit 60.

[0037] The soil load processing unit 60 of this embodiment determines whether the piston member of the boom cylinder 7 has reached a predetermined range during the excavation and loading operation described later. The predetermined range is the range in which the cushioning function operates (cushioning area).

[0038] Then, when the soil load processing unit 60 determines that the piston member of the boom cylinder 7 has reached a predetermined range, it adjusts the measurement result of the soil weight to be obtained according to the state of the shovel 100 at the time this determination is made.

[0039] Here, we will explain the cushioning function. The cushioning function is a function that reduces the speed of the piston member of a hydraulic cylinder when it approaches the stroke end. The cushioning function mitigates the impact when the piston member of the hydraulic cylinder reaches the stroke end. Specifically, when extending the boom cylinder 7 (boom raising operation), when the piston member of the boom cylinder 7 reaches the cushioning area, the pressure in the rod-side oil chamber of the boom cylinder 7 (boom rod pressure) increases, reducing the speed of the piston member. At this time, due to the effect of the increase in boom rod pressure, it becomes impossible to accurately calculate the weight of the soil.

[0040] The cushioning function can be achieved, for example, by controlling a control valve to reduce the flow rate of the hydraulic fluid, or by configuring the hydraulic cylinder so that the flow rate of the hydraulic fluid decreases when the piston member reaches the cushioning area.

[0041] In this embodiment, when it is determined that the piston member of the boom cylinder 7 has reached a predetermined range, the value to be adopted as the measurement result is determined to differ depending on the state of the shovel 100 at that time.

[0042] Therefore, according to this embodiment, the weight of the soil can be obtained as a measurement result, calculated in a state where the influence of the boom cylinder 7's piston member reaching a predetermined range is suppressed. Furthermore, according to this embodiment, if the weight of the soil calculated between the start of the boom 4's lifting operation and the time the boom cylinder 7's piston member reaches a predetermined range has been determined as a measurement result, this weight of soil is obtained as the measurement result. Therefore, according to this embodiment, the range in which the weight of soil can be measured with high accuracy can be maximized. Details of the soil load processing unit 60 will be described later.

[0043] Furthermore, some of the functions of controller 30 may be implemented by other controllers (control devices). That is, the functions of controller 30 may be implemented in a manner distributed among multiple controllers. For example, machine guidance functions and machine control functions may be implemented by dedicated controllers (control devices).

[0044] The discharge pressure sensor 28 detects the discharge pressure of the main pump 14. The 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 later.

[0045] As described above, the operating pressure sensor 29 detects the pilot pressure on the secondary side of the operating device 26, that is, the pilot pressure corresponding to the operating state (e.g., operating direction, operating amount, etc.) of each operating element (i.e., hydraulic actuator) in the operating device 26. The detection signals of the pilot pressure corresponding to the operating state of the lower traveling body 1, upper slewing body 3, boom 4, arm 5, and bucket 6 in the operating device 26, detected by the operating pressure sensor 29, are received by the controller 30. The operating pressure sensor 29 includes, for example, operating pressure sensors 29A to 29C, as described later.

[0046] Alternatively, instead of the operating pressure sensor 29, other sensors capable of detecting the operating state of each operating element in the operating device 26 may be provided, such as encoders or potentiometers capable of detecting the amount of operation (tilt amount) or tilt direction of lever devices 26A to 26C.

[0047] The proportional valve 31 is provided in the pilot line connecting the pilot pump 15 and the shuttle valve 32, and is configured to change its flow area (the cross-sectional area through which hydraulic fluid can flow). The proportional valve 31 operates in response to control commands input from the controller 30. As a result, even when the operating device 26 (specifically, lever devices 26A to 26C) is not operated by the operator, the controller 30 can supply the hydraulic fluid discharged from the pilot pump 15 to the corresponding control valve's pilot port 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 later.

[0048] The display device 40 is located in a place easily visible to a seated operator inside 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 CAN (Controller Area Network), or it may be connected to the controller 30 via a one-to-one dedicated line.

[0049] The input device 42 is located within reach of a seated operator in the cabin 10 and receives various operation inputs from the operator, outputting signals corresponding to the operation 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 parts of lever devices 26A to 26C, and button switches, levers, toggles, rotary dials, etc., installed around the display device 40. Signals corresponding to the operations performed on the input device 42 are received by the controller 30.

[0050] The audio output device 43 is, for example, installed inside the cabin 10 and connected to the controller 30, and outputs sound 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 information by voice in response to an audio output command from the controller 30.

[0051] The storage device 47 is, for example, located inside the cabin 10 and stores various 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 the operation of the shovel 100, or it may store information acquired via various devices before the operation of the shovel 100 begins. The storage device 47 may store data relating to the target construction surface, acquired via a communication device T1, or set via an input device 42, for example. The target construction surface may be set (saved) by the operator of the shovel 100, or it may be set by a construction manager, etc.

[0052] The boom angle sensor S1 is attached to the boom 4 and detects the elevation angle of the boom 4 relative to the upper slewing body 3 (hereinafter referred to as the "boom angle"), for example, the angle formed by the straight line connecting the pivot points at both ends of the boom 4 with respect to the slewing plane of the upper slewing body 3 in a side view. The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, a 6-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 the 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. The detection signal corresponding to the boom angle from the boom angle sensor S1 is input to the controller 30.

[0053] 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 "arm angle"). For example, in a side view, it detects the angle formed by the line connecting the pivot points at both ends of the arm 5 and the line connecting the pivot points at both ends of the boom 4. The detection signal corresponding to the arm angle from the arm angle sensor S2 is input to the controller 30.

[0054] 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, in a side view, it detects the angle formed by the line connecting the pivot point and the tip (toe) of the bucket 6 with respect to the line connecting the pivot points at both ends of the arm 5. The detection signal corresponding to the bucket angle from the bucket angle sensor S3 is input to the controller 30.

[0055] The machine tilt sensor S4 detects the tilt state of the machine (upper rotating body 3 or lower traveling body 1) relative to the horizontal plane. The machine tilt sensor S4 is, for example, attached to the upper rotating body 3 and detects the tilt angle of the shovel 100 (i.e., the upper rotating body 3) around two axes in the longitudinal and lateral directions (hereinafter referred to as "longitudinal tilt angle" and "lateral tilt angle"). The machine tilt sensor S4 may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an IMU, etc. The detection signals corresponding to the tilt angles (longitudinal tilt angle and lateral tilt angle) detected by the machine tilt sensor S4 are input to the controller 30.

[0056] The rotation state sensor S5 outputs detection information regarding the rotation state of the upper rotating body 3. The rotation state sensor S5 detects, for example, the rotation angular velocity and rotation angle of the upper rotating body 3. The rotation state sensor S5 may include, for example, a gyro sensor, a resolver, a rotary encoder, etc. The detection signals corresponding to the rotation angle and rotation angular velocity of the upper rotating body 3 detected by the rotation state sensor S5 are taken up by the controller 30. The boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine tilt sensor S4, and rotation state sensor S5 are included in the attitude sensor. The attitude sensor detects not only the tip position of the bucket 6, but also the boom angle, boom angular velocity, boom angular acceleration, etc.

[0057] The imaging device S6, acting as a spatial recognition device, images the area around the shovel 100. The imaging device S6 includes a front camera S6F that images the area in front of the shovel 100, a left camera S6L that images the area to the left of the shovel 100, a right camera S6R that images the area to the right of the shovel 100, and a rear camera S6B that images the area behind the shovel 100.

[0058] The front camera S6F is mounted, for example, on the ceiling of the cabin 10, i.e., inside the cabin 10. Alternatively, the front camera S6F may be mounted on the roof of the cabin 10, the side of the boom 4, or other external locations within the cabin 10. The left camera S6L is mounted on the upper left end of the upper surface of the upper slewing body 3, the right camera S6R is mounted on the upper right end of the upper surface of the upper slewing body 3, and the rear camera S6B is mounted on the upper rear end of the upper surface of the upper slewing body 3.

[0059] The imaging device S6 (cameras S6F, S6B, S6L, S6R) is, for example, a monocular wide-angle camera with a very wide field of view. Alternatively, the imaging device S6 may be a stereo camera or a depth-sensing camera. Images captured by the imaging device S6 are received by the controller 30 via the display device 40.

[0060] The imaging device S6, as a spatial recognition device, may also 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 or a distance image sensor. The spatial recognition device is, for example, a monocular camera having an image sensor such as a CCD or CMOS, and outputs the captured image to the display device 40. The spatial recognition device may also be configured to calculate the distance from the spatial recognition device or the shovel 100 to the recognized object. In addition to the imaging device S6, other object detection devices such as an ultrasonic sensor, millimeter-wave radar, LiDAR (Light Detection And Ranging), or infrared sensor may be provided as spatial recognition devices. When using millimeter-wave radar, ultrasonic sensors, or laser radar as a spatial recognition device, multiple signals (such as laser light) may be transmitted to an object, and the distance and direction of the object may be detected from the reflected signals by receiving the reflected signals.

[0061] The imaging device S6 may also be directly connected to the controller 30 for communication.

[0062] The boom cylinder 7 is equipped with a boom rod pressure sensor S7R, a boom bottom pressure sensor S7B, and a boom cylinder stroke sensor S7C. The arm cylinder 8 is equipped with an arm rod pressure sensor S8R, an arm bottom pressure sensor S8B, and an arm cylinder stroke sensor S8C. The bucket cylinder 9 is equipped with a bucket rod pressure sensor S9R, a bucket bottom pressure sensor S9B, and a bucket cylinder stroke sensor S9C. The boom rod pressure sensor S7R, boom bottom pressure sensor S7B, arm rod pressure sensor S8R, arm bottom pressure sensor S8B, bucket rod pressure sensor S9R, and bucket bottom pressure sensor S9B are collectively referred to as "cylinder pressure sensors." The boom cylinder stroke sensor S7C, arm cylinder stroke sensor S8C, and bucket cylinder stroke sensor S9C are also referred to as "cylinder stroke sensors."

[0063] The boom rod pressure sensor S7R detects the pressure in the rod-side oil chamber of the boom cylinder 7 (boom rod pressure). The boom bottom pressure sensor S7B detects the pressure in the bottom-side oil chamber of the boom cylinder 7 (boom bottom pressure). The boom cylinder stroke sensor S7C detects the stroke amount of the boom cylinder 7 (boom stroke amount).

[0064] The arm rod pressure sensor S8R detects the pressure in the rod-side oil chamber of the arm cylinder 8 (arm rod pressure). The arm bottom pressure sensor S8B detects the pressure in the bottom-side oil chamber of the arm cylinder 8 (arm bottom pressure). The arm cylinder stroke sensor S8C detects the stroke amount of the arm cylinder 8 (arm stroke amount).

[0065] The bucket rod pressure sensor S9R detects the pressure in the rod-side oil chamber of the bucket cylinder 9 (bucket rod pressure). The bucket bottom pressure sensor S9B detects the pressure in the bottom-side oil chamber of the bucket cylinder 9 (bucket bottom pressure). The bucket cylinder stroke sensor S9C detects the stroke amount of the bucket cylinder 9 (bucket stroke amount).

[0066] The positioning device P1 measures the position and orientation of the upper rotating body 3. The positioning device P1 is, for example, a GNSS (Global Navigation Satellite System) compass, which detects the position and orientation of the upper rotating body 3, and the detection signal corresponding to the position and orientation of the upper rotating body 3 is input to the controller 30. In addition, 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 replaced by an orientation sensor attached to the upper rotating body 3.

[0067] The communication device T1 communicates with external devices through a predetermined network, including a mobile communication network with a base station as its endpoint, a satellite communication network, and the Internet network. The communication device T1 is, for example, a mobile communication module that supports 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.

[0068] The machine guidance unit 50 performs, for example, control of the excavator 100 related to machine guidance functions. The machine guidance unit 50 transmits work information, such as the distance between the target construction surface and the tip of the attachment, specifically the working area 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 pre-stored in the storage device 47, for example, as described above. Data regarding the target construction surface is expressed in, for example, a reference coordinate system. The reference coordinate system is, for example, the World Geodetic System. The World Geodetic System is a three-dimensional orthogonal XYZ coordinate system with its origin at the center of gravity of the Earth, the X-axis pointing in the direction of the intersection of the Greenwich Meridian and the equator, the Y-axis pointing in the direction of 90 degrees east longitude, and the Z-axis pointing in the direction of the North Pole. The operator may designate any point on the construction site as a reference point and set the target construction surface based on its relative position to the reference point via the input device 42. The working parts of the bucket 6 are, for example, the tips of the bucket 6 and the back of the bucket 6. Also, if, for example, a breaker is used as an 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 through the display device 40, the voice output device 43, etc., and guides the operator's operation of the shovel 100 through the operating device 26.

[0069] Furthermore, the machine guidance unit 50 performs, for example, control of the shovel 100 with respect to machine control functions. The machine guidance unit 50 may, for example, automatically operate the boom 4, arm 5, and at least one of the bucket 6 so that the tip position of the bucket 6 coincides with the target construction surface when the operator is manually performing the excavation operation.

[0070] The machine guidance unit 50 acquires information from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine body tilt sensor S4, slewing state sensor S5, imaging device S6, positioning device P1, communication device T1, and input device 42, etc. Based on the acquired information, the machine guidance unit 50 calculates the distance between the bucket 6 and the target construction surface, notifies the operator of the degree of the distance between the bucket 6 and the target construction surface through voice from the voice output device 43 and an image displayed on the display device 40, and automatically controls the movement of the attachment so that the tip of the attachment (specifically, the working part such as the claws or back of the bucket 6) aligns with the target construction surface. The machine guidance unit 50 includes, as a detailed functional configuration related to the machine guidance function and machine control function, a position calculation unit 51, a distance calculation unit 52, an information transmission unit 53, a control unit 54, and a slewing angle calculation unit 55.

[0071] The position calculation unit 51 calculates the position of a predetermined positioning target. For example, the position calculation unit 51 calculates the coordinate points in the reference coordinate system of the tip of the attachment, specifically the working parts such as the claws and back of the bucket 6. Specifically, the position calculation unit 51 calculates the coordinate points of the working parts of the bucket 6 from the elevation angles (boom angle, arm angle, and bucket angle) of the boom 4, arm 5, and bucket 6, respectively.

[0072] The distance calculation unit 52 calculates the distance between two positioning targets. For example, the distance calculation unit 52 calculates the distance between the tip of the attachment, specifically the working part such as the claw or back of the bucket 6, and the target construction surface. The distance calculation unit 52 may also calculate the angle (relative angle) between the back of the bucket 6, which is the working part, and the target construction surface.

[0073] The information transmission unit 53 transmits (notifies) various types of information to the operator of the shovel 100 through predetermined notification means such as the display device 40 and the voice output device 43.

[0074] The control unit 54 individually adjusts the pilot pressure acting on control valves (specifically, control valves 173, 175L, 175R, and 174) corresponding to multiple hydraulic actuators (specifically, the swing hydraulic motor 2A, boom cylinder 7, and bucket cylinder 9) in accordance with the manual operation of the excavator 100 by the operator through the operating device 26. This enables the control unit 54 to realize the operation of the hydraulic actuators in response to the operator's operation.

[0075] The rotation angle calculation unit 55 calculates the rotation angle of the upper rotating body 3. This allows the controller 30 to determine the current orientation of the upper rotating body 3. The rotation angle calculation unit 55 calculates the rotation angle based on the angle of the front-rear axis of the upper rotating body 3 with respect to the reference direction, for example, based on the output signal of the GNSS compass included in the positioning device P1. Alternatively, the rotation angle calculation unit 55 may calculate the rotation angle based on the detection signal of the rotation state sensor S5. Furthermore, if a reference point is set at the construction site, the rotation angle calculation unit 55 may use the direction from the rotation axis to the reference point as the reference direction.

[0076] The rotation angle indicates the direction in which the attachment's working surface extends relative to the reference direction. The attachment's working surface is, for example, a virtual plane that traverses the attachment longitudinally and is positioned perpendicular to the rotation plane. The rotation plane is, for example, a virtual plane that includes the bottom surface of the rotation frame perpendicular to the rotation axis. The controller 30 (machine guidance unit 50) determines, for example, that the upper rotating body 3 is directly facing the target construction surface when it determines that the attachment's working surface includes the normal to the target construction surface.

[0077] 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 by the sediment load processing unit 60 as a condition for measuring the weight of the sediment (for example, to determine whether or not the upper rotating body 3 has rotated).

[0078] The slewing hydraulic motor 2A has a first port 2A1 and a second port 2A2. Hydraulic sensor 21 detects the hydraulic fluid pressure at the first port 2A1 of the slewing hydraulic motor 2A. Hydraulic sensor 22 detects the hydraulic fluid pressure at the second port 2A2 of the slewing hydraulic motor 2A. Detection signals corresponding to the discharge pressure detected by hydraulic sensors 21 and 22 are input to the controller 30.

[0079] Furthermore, the first port 2A1 is connected to the hydraulic fluid 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 fluid from the first port 2A1 side to the hydraulic fluid tank. Similarly, the second port 2A2 is connected to the hydraulic fluid 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 fluid from the second port 2A2 side to the hydraulic fluid tank.

[0080] [Excavator hydraulic system] Next, the hydraulic system of the excavator 100 according to this embodiment will be described with reference to Figure 3. Figure 3 is a schematic diagram showing an example of the configuration of the hydraulic system of the excavator according to this embodiment. In Figure 3, the mechanical power system, hydraulic fluid line, pilot line, and electrical control system are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively, as in Figure 2 and other figures.

[0081] The hydraulic system realized by the hydraulic circuit shown in Figure 3 circulates hydraulic fluid from the main pumps 14L and 14R, driven by the engine 11, through the center bypass oil passages C1L and C1R and the parallel oil passages C2L and C2R to the hydraulic fluid tank.

[0082] The center bypass oil passage C1L starts from the main pump 14L and passes sequentially through control valves 171, 173, 175L, and 176L located within the control valve 17, before reaching the hydraulic oil tank.

[0083] The center bypass oil passage C1R starts from the main pump 14R and passes sequentially through control valves 172, 174, 175R, and 176R located within the control valve 17, before reaching the hydraulic oil tank.

[0084] The control valve 171 is a spool valve that supplies the hydraulic fluid discharged from the main pump 14L to the travel hydraulic motor 1L, and also discharges the hydraulic fluid discharged by the travel hydraulic motor 1L to the hydraulic fluid tank.

[0085] The control valve 172 is a spool valve that supplies the hydraulic fluid discharged from the main pump 14R to the travel hydraulic motor 1R, and also discharges the hydraulic fluid discharged by the travel hydraulic motor 1R to the hydraulic fluid tank.

[0086] The control valve 173 is a spool valve that supplies the hydraulic fluid discharged from the main pump 14L to the swivel hydraulic motor 2A, and also discharges the hydraulic fluid discharged by the swivel hydraulic motor 2A to the hydraulic fluid tank.

[0087] The control valve 174 is a spool valve that supplies the hydraulic fluid discharged from the main pump 14R to the bucket cylinder 9 and discharges the hydraulic fluid in the bucket cylinder 9 to the hydraulic fluid tank.

[0088] Control valves 175L and 175R are spool valves that supply the hydraulic fluid discharged by the main pumps 14L and 14R to the boom cylinder 7, and also discharge the hydraulic fluid from the boom cylinder 7 to the hydraulic fluid tank.

[0089] Control valves 176L and 176R are spool valves that supply the hydraulic fluid discharged by the main pumps 14L and 14R to the arm cylinder 8, and also discharge the hydraulic fluid from the arm cylinder 8 to the hydraulic fluid tank.

[0090] Control valves 171, 172, 173, 174, 175L, 175R, 176L, and 176R each adjust the flow rate of hydraulic fluid supplied to and discharged from the hydraulic actuator, or switch the direction of flow, in accordance with the pilot pressure acting on the pilot port.

[0091] The parallel oil passage C2L supplies the hydraulic fluid 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 control valve 171 and is configured to supply the hydraulic fluid for the main pump 14L in parallel to each of the control valves 171, 173, 175L, and 176R. As a result, the parallel oil passage C2L can supply hydraulic fluid to the control valve further downstream if the flow of hydraulic fluid through the center bypass oil passage C1L is restricted or blocked by any of the control valves 171, 173, or 175L.

[0092] The parallel oil passage C2R supplies hydraulic fluid for the main pump 14R to 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 control valve 172 and is configured to supply hydraulic fluid for the main pump 14R in parallel to each of the control valves 172, 174, 175R, and 176R. As a result, the parallel oil passage C2R can supply hydraulic fluid to the control valves further downstream if the flow of hydraulic fluid through the center bypass oil passage C1R is restricted or blocked by any of the control valves 172, 174, or 175R.

[0093] Regulators 13L and 13R adjust the discharge volume of main pumps 14L and 14R by adjusting the tilt angle of the swash plate of the main pumps 14L and 14R, respectively, under the control of controller 30.

[0094] The discharge pressure sensor 28L detects the discharge pressure of the main pump 14L, and the detection signal corresponding to the detected discharge pressure is input to the controller 30. The same applies to the discharge pressure sensor 28R. As a result, the controller 30 can control the regulators 13L and 13R according to the discharge pressure of the main pumps 14L and 14R.

[0095] In the center bypass oil passages C1L and C1R, negative control throttles (hereinafter referred to as "negative throttles") 18L and 18R are provided between the downstream control valves 176L and 176R and the hydraulic oil tank, respectively. As a result, the flow of hydraulic oil discharged by the main pumps 14L and 14R is restricted by the negative control throttles 18L and 18R. The negative control throttles 18L and 18R then generate a control pressure (hereinafter referred to as "negative control pressure") to control the regulators 13L and 13R.

[0096] The negative control pressure sensors 19L and 19R detect the negative control pressure. The detection signals corresponding to the negative control pressure detected by the negative control pressure sensors 19L and 19R are input to the controller 30.

[0097] The controller 30 may control the regulators 13L and 13R in accordance with the discharge pressure of the main pumps 14L and 14R detected by the discharge pressure sensors 28L and 28R, thereby adjusting the discharge volume of the main pumps 14L and 14R. For example, the controller 30 may reduce the discharge volume by controlling the regulator 13L in accordance with an increase in the discharge pressure of the main pump 14L, thereby adjusting the swash plate tilt angle of the main pump 14L. The same applies to the regulator 13R. In this way, the controller 30 can control the total horsepower of the main pumps 14L and 14R so that the absorption horsepower of the main pumps 14L and 14R, which is expressed as the product of discharge pressure and discharge volume, does not exceed the output horsepower of the engine 11.

[0098] Furthermore, the controller 30 may adjust the discharge rate of the main pumps 14L and 14R by controlling the regulators 13L and 13R in accordance with the negative control pressure detected by the negative control pressure sensors 19L and 19R. For example, the controller 30 may decrease the discharge rate of the main pumps 14L and 14R as the negative control pressure increases, and increase the discharge rate of the main pumps 14L and 14R as the negative control pressure decreases.

[0099] Specifically, in the standby state where none of the hydraulic actuators in the shovel 100 are operated (as shown in Figure 3), the hydraulic fluid discharged from the main pumps 14L and 14R passes through the center bypass oil passages C1L and C1R to the negative control throttles 18L and 18R. The flow of hydraulic fluid discharged from the main pumps 14L and 14R increases the negative control pressure generated upstream of the negative control throttles 18L and 18R. As a result, the controller 30 reduces the discharge volume of the main pumps 14L and 14R to the minimum allowable discharge volume, suppressing pressure loss (pumping loss) as the discharged hydraulic fluid passes through the center bypass oil passages C1L and C1R.

[0100] On the other hand, when any of the hydraulic actuators is operated through the operating device 26, the hydraulic fluid discharged from the main pumps 14L and 14R flows into the hydraulic actuator being operated via the control valve corresponding to the hydraulic actuator being operated. The flow of hydraulic fluid discharged from the main pumps 14L and 14R reduces or eliminates the amount reaching the negative control thresholds 18L and 18R, thereby lowering the negative control pressure generated upstream of the negative control thresholds 18L and 18R. As a result, the controller 30 increases the discharge volume of the main pumps 14L and 14R, circulating sufficient hydraulic fluid to the hydraulic actuator being operated, and ensuring that the hydraulic actuator is driven reliably.

[0101] [Details of the excavator's machine control function configuration] Next, with reference to Figure 4, the details of the configuration of the machine control function of the shovel 100 will be described. Figure 4 is a schematic diagram showing an example of the operating system components of the hydraulic system of the shovel according to this embodiment.

[0102] Specifically, Figure 4(A) shows an example of a pilot circuit that applies pilot pressure to control valves 175L and 175R that hydraulically control the boom cylinder 7. Figure 4(B) shows an example of a pilot circuit that applies pilot pressure to control valve 174 that hydraulically controls the bucket cylinder 9. Figure 4(C) shows an example of a pilot circuit that applies pilot pressure to control valve 173 that hydraulically controls the swing hydraulic motor 2A.

[0103] As shown in Figure 4(A), the lever device 26A is used by an operator to operate the boom cylinder 7 corresponding to the boom 4. The lever device 26A uses the hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure to the secondary side according to the operation being performed.

[0104] The shuttle valve 32AL has two inlet ports, one connected to the pilot line on the secondary side of the lever device 26A corresponding to the operation of raising the boom 4 (hereinafter referred to as "boom raising operation") and the other to the pilot line on the secondary side of the proportional valve 31AL, respectively. Its outlet ports are connected to the pilot port on the right side of the control valve 175L and the pilot port on the left side of the control valve 175R.

[0105] The shuttle valve 32AR has two inlet ports, one connected to the pilot line on the secondary side of the lever device 26A corresponding to the operation of lowering the boom 4 (hereinafter referred to as "boom lowering operation") and the other to the pilot line on the secondary side of the proportional valve 31AR, respectively, and its outlet port is connected to the pilot port on the right side of the control valve 175R.

[0106] In other words, the lever device 26A, via shuttle valves 32AL and 32AR, applies pilot pressure to the pilot ports of control valves 175L and 175R according to the operation content (e.g., direction of operation and amount of operation). Specifically, when the boom is raised, the lever device 26A outputs pilot pressure corresponding to the amount of operation to one inlet port of shuttle valve 32AL, which then acts on the right pilot port of control valve 175L and the left pilot port of control valve 175R via shuttle valve 32AL. Also, when the boom is lowered, the lever device 26A outputs pilot pressure corresponding to the amount of operation to one inlet port of shuttle valve 32AR, which then acts on the right pilot port of control valve 175R via shuttle valve 32AR.

[0107] The proportional valve 31AL operates in response to the control current input from the controller 30. Specifically, the proportional valve 31AL uses the hydraulic fluid 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.

[0108] The proportional valve 31AR operates in response to a control current input from the controller 30. Specifically, the proportional valve 31AR uses the hydraulic fluid 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-hand pilot port of the control valve 175R via the shuttle valve 32AR.

[0109] In other words, proportional valves 31AL and 31AR can adjust the pilot pressure output to the secondary side so that control valves 175L and 175R can be stopped at any valve position, regardless of the operating state of the lever device 26A.

[0110] The proportional valve 33AL functions as a control valve for machine control, similar to the proportional valve 31AL. The proportional valve 33AL is located in the pipeline connecting the operating device 26 and the shuttle valve 32AL, and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional valve 33AL operates in response to control commands output by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic fluid 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, independently of the operator's operation of the operating device 26.

[0111] Similarly, the proportional valve 33AR functions as a control valve for machine control. The proportional valve 33AR is located in the pipeline connecting the operating device 26 and the shuttle valve 32AR and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional valve 33AR operates in response to control commands output by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic fluid 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, independently of the operator's operation of the operating device 26.

[0112] The operating pressure sensor 29A detects the operator's operation on the lever device 26A in the form of pressure (operating pressure). The detection signal corresponding to the operating pressure detected by the operating pressure sensor 29A is received by the controller 30. This allows the controller 30 to understand the operation performed on the lever device 26A.

[0113] The controller 30 can supply hydraulic fluid discharged from the pilot pump 15 to the pilot port on the right side of the control valve 175L and the pilot port on the left side of the control valve 175R via the proportional valve 31AL and the shuttle valve 32AL, independently of the boom-raising operation performed by the operator on the lever device 26A. Furthermore, the controller 30 can supply hydraulic fluid discharged from the pilot pump 15 to the pilot port on the right side of the control valve 175R via the proportional valve 31AR and the shuttle valve 32AR, independently of the boom-lowering operation performed by the operator on the lever device 26A. In other words, the controller 30 can automatically control the raising and lowering of the boom 4. Additionally, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to a specific operating device 26, even when an operation is being performed on that specific operating device 26.

[0114] The proportional valve 33AL operates in response to a control command (current command) output by the controller 30. It reduces the pilot pressure caused by the hydraulic fluid 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 caused by the hydraulic fluid 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 can adjust the pilot pressure so that the control valves 175L and 175R can be stopped at any valve position.

[0115] With this configuration, even when the boom is being raised by the operator, the controller 30 can, if necessary, reduce the pilot pressure acting on the raising-side pilot ports of the control valve 175 (the left pilot port of control valve 175L and the right pilot port of control valve 175R) and forcibly stop the closing operation of the boom 4. The same applies when the boom is being lowered by the operator and the lowering operation of the boom 4 needs to be forcibly stopped.

[0116] Alternatively, even when the boom is being raised by the operator, the controller 30 may, if necessary, control the proportional valve 31AR to increase the pilot pressure acting on the pilot port on the lowering side of the control valve 175 (the right-hand pilot port of the control valve 175R), which is opposite the pilot port on the raising side of the control valve 175, thereby forcibly stopping the raising movement of the boom 4 by forcibly returning the control valve 175 to the neutral position. In this case, the proportional valve 33AL may be omitted. The same applies when the boom is being lowered by the operator and the lowering movement of the boom 4 is to be forcibly stopped.

[0117] As shown in Figure 4(B), the lever device 26B is used by an operator to operate the bucket cylinder 9 corresponding to the bucket 6. The lever device 26B uses the hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure to the secondary side according to the operation.

[0118] The shuttle valve 32BL has two inlet ports, one connected to the pilot line on the secondary side of the lever device 26B corresponding to the operation of closing the bucket 6 (hereinafter referred to as "bucket closing operation") and the other to the pilot line on the secondary side of the proportional valve 31BL, respectively, and its outlet port is connected to the pilot port on the left side of the control valve 174.

[0119] The shuttle valve 32BR has two inlet ports, one connected to the pilot line on the secondary side of the lever device 26B corresponding to the operation of opening the bucket 6 (hereinafter referred to as "bucket opening operation") and the other to the pilot line on the secondary side of the proportional valve 31BR, respectively, and its outlet port is connected to the pilot port on the right side of the control valve 174.

[0120] In other words, the lever device 26B applies pilot pressure corresponding to the operation to the pilot port of the control valve 174 via shuttle valves 32BL and 32BR. Specifically, when a bucket closing operation is performed, the lever device 26B outputs pilot pressure corresponding to the amount of operation to one inlet port of shuttle valve 32BL, which then acts on the left pilot port of the control valve 174 via shuttle valve 32BL. Similarly, when a bucket opening operation is performed, the lever device 26B outputs pilot pressure corresponding to the amount of operation to one inlet port of shuttle valve 32BR, which then acts on the right pilot port of the control valve 174 via shuttle valve 32BR.

[0121] The proportional valve 31BL operates in response to the control current input from the controller 30. Specifically, the proportional valve 31BL uses the hydraulic fluid 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.

[0122] The proportional valve 31BR operates in response to the control current input from the controller 30. Specifically, the proportional valve 31BR uses the hydraulic fluid 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-hand pilot port of the control valve 174 via the shuttle valve 32BR.

[0123] In other words, proportional valves 31BL and 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.

[0124] The proportional valve 33BL functions as a control valve for machine control, similar to the proportional valve 31BL. The proportional valve 33BL is located in the pipeline connecting the operating device 26 and the shuttle valve 32BL, and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional valve 33BL operates in response to control commands output by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic fluid 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, independently of the operator's operation of the operating device 26.

[0125] Similarly, the proportional valve 33BR functions as a control valve for machine control. The proportional valve 33BR is located in the pipeline connecting the operating device 26 and the shuttle valve 32BR and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional valve 33BR operates in response to control commands output by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic fluid 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, independently of the operator's operation of the operating device 26.

[0126] The operating pressure sensor 29B detects the operator's operation on the lever device 26B in the form of pressure (operating pressure). The detection signal corresponding to the operating pressure detected by the operating pressure sensor 29B is received by the controller 30. This allows the controller 30 to understand the operation of the lever device 26B.

[0127] The controller 30 can supply hydraulic fluid discharged from the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31BL and the shuttle valve 32BL, independently of the operator's bucket closing operation on the lever device 26B. Furthermore, the controller 30 can supply hydraulic fluid discharged from the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31BR and the shuttle valve 32BR, independently of the operator's bucket opening operation on the lever device 26B. In other words, the controller 30 can automatically control the opening and closing operation of the bucket 6. Additionally, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to a specific operating device 26, even when an operation is being performed on that specific operating device 26.

[0128] Furthermore, the operation of proportional valves 33BL and 33BR, which forcibly stop the movement of bucket 6 when the operator is performing a bucket closing or bucket opening operation, is the same as the operation of proportional valves 33AL and 33AR, which forcibly stop the movement of boom 4 when the operator is performing a boom raising or boom lowering operation, and therefore, redundant explanations are omitted.

[0129] As shown in Figure 4(C), the lever device 26C is used by an operator to operate the slewing hydraulic motor 2A corresponding to the upper slewing body 3 (slewing mechanism 2). The lever device 26C uses the hydraulic fluid discharged from the pilot pump 15 to output a pilot pressure to the secondary side according to the operation being performed.

[0130] The shuttle valve 32CL has two inlet ports, one connected to the pilot line on the secondary side of the lever device 26C corresponding to the leftward rotation operation of the upper slewing body 3 (hereinafter referred to as "leftward rotation operation") and the other to the pilot line on the secondary side of the proportional valve 31CL, respectively, and its outlet port is connected to the pilot port on the left side of the control valve 173.

[0131] The shuttle valve 32CR has two inlet ports, one connected to the pilot line on the secondary side of the lever device 26C corresponding to the rightward rotation operation of the upper slewing body 3 (hereinafter referred to as "rightward rotation operation") and the other to the pilot line on the secondary side of the proportional valve 31CR, respectively, and its outlet port is connected to the pilot port on the right side of the control valve 173.

[0132] In other words, the lever device 26C applies pilot pressure to the pilot port of the control valve 173 via shuttle valves 32CL and 32CR, according to the operation in the left or right direction. Specifically, when a left turn operation is performed, the lever device 26C outputs pilot pressure corresponding to the amount of operation to one inlet port of shuttle valve 32CL, which then acts on the left pilot port of the control valve 173 via shuttle valve 32CL. Similarly, when a right turn operation is performed, the lever device 26C outputs pilot pressure corresponding to the amount of operation to one inlet port of shuttle valve 32CR, which then acts on the right pilot port of the control valve 173 via shuttle valve 32CR.

[0133] The proportional valve 31CL operates in response to the control current input from the controller 30. Specifically, the proportional valve 31CL uses the hydraulic fluid 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.

[0134] The proportional valve 31CR operates in response to a control current input from the controller 30. Specifically, the proportional valve 31CR uses the hydraulic fluid 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-hand pilot port of the control valve 173 via the shuttle valve 32CR.

[0135] In other words, 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.

[0136] The proportional valve 33CL functions as a control valve for machine control, similar to the proportional valve 31CL. The proportional valve 33CL is located in the pipeline connecting the operating device 26 and the shuttle valve 32CL, and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional valve 33CL operates in response to control commands output by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic fluid 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, independently of the operator's operation of the operating device 26.

[0137] Similarly, the proportional valve 33CR functions as a control valve for machine control. The proportional valve 33CR is located in the pipeline connecting the operating device 26 and the shuttle valve 32CR and is configured to change the flow area of ​​the pipeline. In this embodiment, the proportional valve 33CR operates in response to control commands output by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic fluid 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, independently of the operator's operation of the operating device 26.

[0138] The operating pressure sensor 29C detects the operator's operating state on the lever device 26C in the form of pressure (operating pressure). The detection signal corresponding to the operating pressure detected by the operating pressure sensor 29C is received by the controller 30. This allows the controller 30 to understand the operation of the lever device 26C in the left-right direction.

[0139] The controller 30 can supply hydraulic fluid 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 leftward rotation operation on the lever device 26C. Furthermore, the controller 30 can supply hydraulic fluid 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 rightward rotation operation on the lever device 26C. In other words, the controller 30 can automatically control the leftward rotation movement of the upper slewing body 3. Additionally, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to a specific operating device 26, even when an operation is being performed on that specific operating device 26.

[0140] Furthermore, the operation of proportional valves 33CL and 33CR, which forcibly stop the movement of the upper slewing body 3 when the operator is performing a slewing operation, is the same as the operation of proportional valves 33AL and 33AR, which forcibly stop the movement of the boom 4 when the operator is performing a boom raising or boom lowering operation, and therefore, redundant explanations are omitted.

[0141] Furthermore, the shovel 100 may also be equipped with a configuration for automatically opening and closing the arm 5, and a configuration for automatically moving the lower traveling body 1 forward or backward. In this case, the components of the hydraulic system 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 in the same way as the components related to the operating system of the boom cylinder 7, etc. (Figures 4(A) to (C)).

[0142] Furthermore, the shovel 100 may communicate with external devices (not shown) indirectly or directly, for example, using a communication device T1.

[0143] Instead of being configured to be operated by an operator in the cabin 10, or in addition to being configured to be remotely operated from outside the cabin 100, the shovel 100 may also be configured to be remotely operated. When the shovel 100 is remotely operated, the cabin 10 may be unoccupied. The following explanation will proceed on the premise that operator operation includes at least one of operation of the operator's control device 26 in the cabin 10 and remote operation by an external operator.

[0144] Remote operation includes, for example, a mode in which the shovel 100 is operated by operation inputs related to the actuator of the shovel 100 performed by a predetermined external device. In this case, the shovel 100 may transmit image information (captured image) output by, for example, a front camera S6F that captures the area in front of the upper rotating body 3 for remote operation to the external device via, for example, the communication device T1 described later. The external device may then display the received image information (captured image) on a display device provided in its own device (hereinafter referred to as the "remote operation display device"). Similarly, 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 operation display device of the external device. This allows the operator of the external device to remotely operate the shovel 100 while checking the display contents, such as captured images and information screens showing the surroundings of the shovel 100, displayed on the remote operation display device. The shovel 100 may then operate actuators in response to remote control signals, which are received from an external device via the communication device T1 and represent the content of the remote control operation, thereby driving the driven elements such as the lower traveling body 1 (left and right crawlers), the upper slewing body 3, the boom 4, the arm 5, and the bucket 6.

[0145] Furthermore, remote operation may include, for example, a mode in which the shovel 100 is operated by external voice input or gesture input from a person (e.g., a worker) in the vicinity of the shovel 100. Specifically, the shovel 100 recognizes voices spoken by nearby workers or gestures made by workers through a voice input device (e.g., a microphone) or gesture input device (e.g., an imaging device) mounted on the shovel 100 (itself). The shovel 100 may then operate actuators according to the content of the recognized voices or gestures to drive driven elements such as the lower traveling body 1 (left and right crawlers), the upper slewing body 3, the boom 4, the arm 5, and the bucket 6.

[0146] 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 electrical signal, rather than a hydraulic pilot type that outputs pilot pressure. In this case, the electrical signal from the operating device 26 is input to the controller 30, and the controller 30 controls each of the control valves 171 to 176 in the control valve 17 according to the input electrical signal, thereby realizing the operation of various hydraulic actuators according to 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 driven by commands from the controller 30. Alternatively, for example, an electromagnetic valve that operates according to an electrical signal from the controller 30 may be placed between the pilot pump 15 and the pilot port of each 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 by an electrical signal corresponding to the amount of operation (for example, the amount of lever operation), thereby increasing or decreasing the pilot pressure and operating each of the control valves 171 to 176 in accordance with the operation performed on the operating device 26.

[0147] Figure 5 shows an example of the configuration of the electric operating system for the excavator according to this embodiment. Here, the operating device 26 is an electromagnetic operating lever, and the controller 30 suppresses vibration of the boom 4 by controlling the pilot pressure to the control valve 17 (control valve 175).

[0148] When an electric operating system equipped with an electric operating lever is employed, the controller 30 can perform autonomous control functions more easily than when a hydraulic operating system equipped with a hydraulic operating lever is employed. The electric operating system in Figure 5 is an example of a boom operating system and mainly consists of a pilot-operated control valve 17, a lever device 26A as an electric operating lever, a controller 30, a solenoid valve 160 for boom raising operation, and a solenoid valve 162 for boom lowering operation. The electric operating system in Figure 5 can also be similarly applied to arm operating systems and bucket operating systems, etc. Hereinafter, electromagnetic operating levers or electric operating levers will also be simply referred to as "electric levers". The lever device 26A is an example of an electric lever.

[0149] The pilot-operated control valve 17 includes a control valve 175 for the boom cylinder 7 (see Figure 3), a control valve 176 for the arm cylinder 8 (see Figure 3), and a control valve 174 for the bucket cylinder 9 (see Figure 3), etc. The solenoid valve 160 is configured to adjust the flow area of ​​the pipeline connecting the pilot pump 15 and the upward-side pilot port of the control valve 175. The solenoid valve 162 is configured to adjust the flow area of ​​the pipeline connecting the pilot pump 15 and the downward-side pilot port of the control valve 175.

[0150] When manual operation is performed, the controller 30 generates a boom-raising operation signal (electrical signal) or a boom-lower operation signal (electrical signal) in response to the operation signal (electrical signal) output by the operation signal generation unit of the lever device 26A. The operation signal output by the operation signal generation unit of the lever device 26A is an electrical signal that changes according to the amount and direction of operation of the lever device 26A.

[0151] Specifically, when the lever device 26A is operated in the boom-raising direction, the controller 30 outputs a boom-raising operation signal (electrical signal) to the solenoid valve 160 according to the amount of lever operation. The solenoid valve 160 adjusts the flow path area according to the boom-raising operation signal (electrical signal) and controls the pilot pressure, which acts as a boom-raising operation signal (pressure signal) acting on the upward-side pilot port of the control valve 175. Similarly, when the lever device 26A is operated in the boom-lower direction, the controller 30 outputs a boom-lower operation signal (electrical signal) to the solenoid valve 162 according to the amount of lever operation. The solenoid valve 162 adjusts the flow path area according to the boom-lower operation signal (electrical signal) and controls the pilot pressure, which acts as a boom-lower operation signal (pressure signal) acting on the downward-side pilot port of the control valve 175.

[0152] When autonomous control is performed, the controller 30, instead of responding to the operation signal (electrical signal) output by the operation signal generation unit of the lever device 26A, for example, generates a boom-raising operation signal (electrical signal) or a boom-lower operation signal (electrical signal) in response to a correction operation signal (electrical signal). The correction operation signal may be an electrical signal generated by the controller 30, or it may be an electrical signal generated by an external control device other than the controller 30.

[0153] [Details of the configuration regarding the soil load detection function of the excavator] Next, with reference to Figure 6, the details of the configuration related to the soil load detection function of the shovel 100 according to this embodiment will be described. Figure 6 is a schematic diagram showing an example of the components related to the soil load detection function of the shovel according to this embodiment.

[0154] In addition to the above-described configuration, the controller 30 includes a soil load processing unit 60 as a functional unit related to the function of detecting the load of soil excavated by the bucket 6.

[0155] The sediment load processing unit 60 includes a confirmation condition determination unit 61, an area determination unit 62, a load weight calculation unit 63, a maximum load amount detection unit 64, an additional load amount calculation unit 65, a remaining load amount calculation unit 66, and a weight determination unit 67.

[0156] Here, we will describe an example of the operation of loading soil (loading material) onto a dump truck using the shovel 100 according to this embodiment.

[0157] First, the shovel 100 controls the attachment to excavate soil with the bucket 6 at the excavation position (excavation operation). Next, the shovel 100 performs a boom-raising operation, raising the boom 4 until the bottom of the bucket 6 is at a desired height from the ground, and rotates the upper slewing body 3 to move the bucket 6 from the excavation position to the soil discharge position (slewing operation). Below the soil discharge position is the bed of a dump truck. Next, at the soil discharge position, the shovel 100 controls the attachment to discharge the soil in the bucket 6, loading the soil into the dump truck bed (soil discharge operation). Next, the shovel 100 rotates the upper slewing body 3 to move the bucket 6 from the soil discharge position to the excavation position (slewing operation). By repeating these operations, the shovel 100 loads the excavated soil into the dump truck bed.

[0158] The confirmation condition determination unit 61 determines whether the state of the shovel 100 satisfies predetermined conditions (confirmation conditions) for determining the weight of soil (an example of an object) loaded into the bucket 6 as a measurement result. In this embodiment, after loading soil or the like into the bucket 6, the confirmation condition determination unit 61 determines whether the detection signal (an example of detection information) related to the raising operation of the boom 4 satisfies a plurality of confirmation conditions.

[0159] More specifically, the confirmation condition determination unit 61 determines whether the detection signal (an example of detection information) related to the raising operation of the boom 4 satisfies all of the multiple confirmation conditions, satisfies some of the multiple confirmation conditions, or does not satisfy any of the multiple confirmation conditions. The multiple confirmation conditions are the first to fourth conditions described later.

[0160] The specific determination method used by the determination condition unit 61 is described below.

[0161] For example, among the multiple confirmation conditions determined by the confirmation condition determination unit 61, the first condition is a condition related to the boom raising operation. Specifically, the confirmation condition determination unit 61 determines that the first condition is met when the boom raising operation by the operator stops. The confirmation condition determination unit 61 may determine whether or not the boom raising operation has stopped based on the pilot pressure corresponding to the operating state of the boom 4.

[0162] The second condition among the multiple confirmation conditions determined by the confirmation condition determination unit 61 is a condition relating to the height of the bucket 6. Specifically, the confirmation condition determination unit 61 determines that the second 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 also be calculated by the distance calculation unit 52.

[0163] The third condition among the multiple confirmation conditions determined by the confirmation condition determination unit 61 is a condition related to the amount the boom 4 is raised. Specifically, the confirmation condition determination unit 61 determines that the third condition is met when the amount the boom 4 is raised is sufficient. The amount the boom 4 is raised is the difference between the height of the boom 4 when the excavation operation is completed and the current height of the boom 4.

[0164] The fourth condition among the multiple confirmation conditions determined by the confirmation condition determination unit 61 is a condition relating to the acceleration of the boom 4 as it moves. Specifically, the confirmation condition determination unit 61 determines that the fourth condition is met if the acceleration of the boom 4 as it moves is within a predetermined range. The acceleration of the boom 4 as it moves may also be the angular acceleration around the foot pin of the boom 4.

[0165] Furthermore, the fourth condition may be a condition relating to the acceleration of the movement of the arm 5. For example, the condition 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 fourth condition is met if the angular acceleration of the arm 5 is above a predetermined lower limit and below a predetermined upper limit, and the acceleration of the movement of the arm 5 is within a predetermined range.

[0166] The confirmation condition determination unit 61 determines the measurement accuracy of the soil weight based on the confirmation conditions that the detection signal has determined to satisfy from among a plurality of confirmation conditions. For example, if the confirmation condition determination unit 61 determines that all of the plurality of confirmation conditions are satisfied, it may use the highest accuracy as the measurement accuracy of the soil weight. Alternatively, if the confirmation condition determination unit 61 satisfies some of the confirmation conditions, it may determine the measurement accuracy of the soil weight to be medium accuracy.

[0167] When the sediment load processing unit 60 determines that the confirmation condition has been met by the confirmation condition determination unit 61, it confirms the sediment weight calculated by the load weight calculation unit 63 (described later) based on the detection signal as the measurement result. Note that the detection signal used by the confirmation condition determination unit 61 for determination is not limited to one, but may be multiple.

[0168] The area determination unit 62 determines whether the piston member of the boom cylinder 7 is within the cushion area at the start of the boom raising operation. In other words, the area determination unit 62 determines whether the piston member of the boom cylinder 7 has reached the cushion area at the start of the boom raising operation.

[0169] Specifically, the area determination unit 62 determines that the piston member of the boom cylinder 7 is within the cushion area at the start of the boom raising operation if the measured value of the boom bottom pressure sensor S7B at the start of the boom raising operation is greater than or equal to a predetermined value. In this embodiment, by doing so, it is possible to automatically determine whether or not the piston member of the boom cylinder 7 is within the cushion area at the start of the boom raising operation.

[0170] Furthermore, the area determination unit 62 determines whether the piston member of the boom cylinder 7 has reached the area in which the cushioning function operates (cushion area). Specifically, the area determination unit 62 may determine that the piston member of the boom cylinder 7 has reached the cushion area when the boom angle detected by the boom angle sensor S1 exceeds a predetermined threshold. Alternatively, for example, the area determination unit 62 may determine that the piston member of the boom cylinder 7 has reached the cushion area when the boom stroke amount detected by the boom cylinder stroke sensor S7C exceeds a predetermined threshold.

[0171] Furthermore, for example, the area determination unit 62 may determine that the piston member of the boom cylinder 7 has reached the cushion area when the amount of change in boom rod pressure detected by the boom rod pressure sensor S7R or the amount of change in boom bottom pressure detected by the boom bottom pressure sensor S7B exceeds a predetermined threshold.

[0172] In this case, the area determination unit 62 does not need to have a predetermined threshold set for, for example, the amount of change in boom rod pressure or boom bottom pressure. In that case, the area determination unit 62 may refer to the operation history up to that point and determine that the piston member of the boom cylinder 7 has reached the cushion area when the amount of change in boom bottom pressure has increased sharply compared with past amounts of change in boom rod pressure or boom bottom pressure. By doing so, it is possible to automatically determine that the piston member of the boom cylinder 7 has reached the cushion area.

[0173] Note that the change in boom rod pressure and boom bottom pressure are the change per unit time (i.e., the derivative). In this way, the boom angle sensor S1, boom cylinder stroke sensor S7C, boom rod pressure sensor S7R, and boom bottom pressure sensor S7B output detection signals related to the raising operation of boom 4.

[0174] The area determination unit 62 may use multiple determination methods from among those described above to determine whether or not the piston member of the boom cylinder 7 has reached the cushion area. By using multiple determination methods in combination in this way, the accuracy of the determination can be improved.

[0175] Furthermore, the area determination unit 62 of this embodiment may determine whether or not the piston member of the boom cylinder 7 has reached the cushion area using any one of the determination methods described above.

[0176] The load weight calculation unit 63 calculates the weight of the soil in the bucket 6 based on the thrust of the boom cylinder 7 (measured values ​​from the boom rod pressure sensor S7R and boom bottom pressure sensor S7B) derived from the detection signal from the cylinder pressure sensor and the center of gravity of the soil, when the height of the bucket 6 is included in the measurement section for measuring the weight of the soil loaded in the bucket 6. 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 according to the embodiment.

[0177] The weight of the soil is calculated, for example, by the balance of 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 weight of the soil and the center of gravity of the soil. In this way, the load weight calculation unit 63 calculates the weight of the soil based on the thrust of the boom cylinder 7 (measured values ​​from the boom rod pressure sensor S7R and boom bottom pressure sensor S7B) and the center of gravity of the soil, which are derived from the detection signal. The center of gravity of the soil is, for example, determined experimentally in advance and stored in the controller 30.

[0178] This embodiment describes an example of calculating the weight of soil based on the thrust of the boom cylinder 7, but the method of calculating the weight of soil is not limited to this. The load weight calculation unit 63 in this embodiment may calculate the weight of soil based on detection signals detected as an operation of the attachment. For example, the load weight calculation unit 63 may calculate the weight of soil 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 it may calculate the weight of soil 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).

[0179] The maximum load capacity detection unit 64 detects the maximum load capacity of the dump truck to be loaded with soil and sand. For example, the maximum load capacity detection unit 64 identifies the dump truck to be loaded with soil and sand based on the image captured by the imaging device S6. Next, the maximum load capacity detection unit 64 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 64 determines the type (size, etc.) of the dump truck based on the image of the identified dump truck. The maximum load capacity detection unit 64 has a table that associates the type of truck with the maximum load capacity, and determines the maximum load capacity of the dump truck based on the type of truck determined from the image and the table. Alternatively, the maximum load capacity, type of truck, etc. of the dump truck may be input via the input device 42, and the maximum load capacity detection unit 64 may determine the maximum load capacity of the dump truck based on the input information from the input device 42.

[0180] The additional load calculation unit 65 calculates the weight of the soil loaded onto the dump truck. Specifically, each time soil is dumped from the bucket 6 onto the dump truck bed, the additional load calculation unit 65 adds the weight of the soil in the bucket 6 calculated by the load weight calculation unit 63 to calculate the additional load (total weight), which is the total weight of the soil loaded onto the dump truck bed. Note that if the dump truck used to load the soil becomes a new dump truck, the additional load is reset.

[0181] The weight determination unit 67 determines the weight of soil to be used as the measurement result, according to the state of the shovel 100 at the time the area determination unit 62 determines that the piston member of the boom cylinder 7 has reached the cushion area. Specifically, if the weight determination unit 67 determines that the measurement result of the soil weight has not been determined (i.e., the shovel 100 does not meet any of the multiple determination conditions) at the time the piston member of the boom cylinder 7 has reached the cushion area, it uses the weight of soil calculated by the load weight calculation unit 63 at that time as the measurement result.

[0182] In other words, the weight determination unit 67 adopts the weight of the soil calculated by the load weight calculation unit 63 at the time the piston member of the boom cylinder 7 reaches the cushion area, if the state of the shovel 100 is after the start of the boom raising operation and the weight of the soil that will be measured has not yet been obtained. In other words, the weight determination unit 67 obtains the weight of the soil at the time the piston member of the boom cylinder 7 reaches the cushion area as the measurement result.

[0183] Furthermore, the soil weight obtained as a measurement result by the weight determination unit 67 at this time may be judged to have low accuracy because the condition of the shovel 100 does not meet any of the multiple determination conditions.

[0184] Furthermore, if the area determination unit 62 determines that the piston member of the boom cylinder 7 has reached the cushion area, the weight determination unit 67 will adopt the determined weight of the soil as the measurement result.

[0185] In other words, the weight determination unit 67 adopts the already determined soil weight as the measurement result when the state of the shovel 100 at the point when the piston member of the boom cylinder 7 reaches the cushion area is after the start of the boom raising operation and the soil weight has been determined. That is, the weight determination unit 67 obtains the already determined soil weight as the measurement result.

[0186] In this embodiment, by determining the weight of the soil to be obtained as a measurement result, the weight of the soil corresponding to the state of the shovel 100 at the time the piston member of the boom cylinder 7 reaches the cushion area can be used as the measurement result, thereby improving the accuracy of the measurement result.

[0187] Furthermore, in this embodiment, the weight of the soil calculated by the load weight calculation unit 63 can be obtained as a measurement result before it is affected by the reaction force in the cushion area, thereby minimizing the influence of the reaction force in the cushion area.

[0188] Furthermore, in this embodiment, the load weight calculation unit 63 calculates the weight of the soil until the piston member of the boom cylinder 7 reaches the cushion area. Therefore, in this embodiment, the measurement area in which the weight of the soil is measured can be made as wide as possible.

[0189] The remaining load calculation unit 66 calculates the remaining load as the difference between the maximum load capacity of the dump truck detected by the maximum load capacity detection unit 64 and the current added load capacity calculated by the added load capacity calculation unit 65. The remaining load capacity is the remaining weight of soil that can be loaded onto the dump truck.

[0190] The display device 40 may also display the weight of soil in the bucket 6 calculated by the load weight calculation unit 63, the maximum load capacity of the dump truck detected by the maximum load capacity detection unit 64, the additional load capacity of the dump truck calculated by the additional load capacity calculation unit 65 (total weight of soil loaded on the cargo bed), and the remaining load capacity of the dump truck calculated by the remaining load capacity calculation unit 66 (remaining weight of soil that can be loaded).

[0191] Furthermore, the system may be configured to display a warning on the display device 40 if the added load exceeds the maximum load capacity. Also, the system may be configured to display a warning on the display device 40 if the calculated weight of soil in the bucket 6 exceeds the remaining load capacity. The warning is not limited to being displayed on the display device 40; it may also be an audio output from the audio output device 43. This prevents the dump truck from being loaded with soil exceeding its maximum load capacity.

[0192] Next, an example of the operation of shovel 100 will be explained using Figure 7. Figure 7 is a diagram illustrating the excavation and loading operations of the shovel.

[0193] 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 position as shown in Figure 7(B). At this time, the excavated soil enters the bucket 6.

[0194] Next, with the upper edge of the bucket 6 approximately horizontal, the operator raises the boom 4 to the position shown in Figure 7(C). At this time, the operator may also close the arm 5 while raising the boom 4.

[0195] Furthermore, when the boom 4 is raised and the height of the boom 4 reaches the measurement section, if the time during which it is determined that the angular acceleration around the foot pin of the boom 4 is less than the first threshold and the change in the thrust of the cylinder (derivative value) is less than the second threshold is longer than a predetermined time, the load weight calculation unit 63 calculates the weight of the soil in the bucket 6. If the conditions for calculating the weight of the soil are not met, the information transmission unit 53 may prompt the operator to perform operations that will satisfy the conditions.

[0196] Then, as shown in Figure 7(D), the operator raises the boom 4 until the bottom of the bucket 6 is at the desired height from the ground. The desired height is, for example, greater than or equal to the height of a dump truck DT (see Figure 7(E) described later). Subsequently, or simultaneously, the operator rotates the upper slewing body 3 as indicated by arrow AR1, moving the bucket 6 to the position where the soil will be discharged. This movement of the shovel is called the boom-raising and slewing movement, and this movement section is called the boom-raising and slewing movement section.

[0197] Once the operator completes the boom raising and slewing motion, they open the arm 5 and bucket 6 as shown in Figure 7(E) to discharge the soil from the bucket 6. This operation of the shovel 100 is called the dumping operation, and this operation section is called the dumping operation section. During the dumping operation, the operator may also open only the bucket 6 to discharge the soil.

[0198] Once the dumping operation is complete, the operator rotates the upper slewing body 3 as indicated by arrow AR2, as shown in Figure 7(F), to move the bucket 6 directly above the excavation position. At the same time as the rotation, the boom 4 is lowered to lower the bucket 6 to the desired height above the excavation target. This movement of the shovel is called the boom lowering and slewing operation, and this operation section is called the boom lowering and slewing operation section.

[0199] The operator carries out the excavation and loading operations by repeating a cycle consisting of "excavation," "boom raising and slewing," "dumping," and "boom lowering and slewing."

[0200] Next, an example of the process for determining the weight of the cargo will be explained using Figure 8. Figure 8 is a flowchart showing an example of the process for determining the weight of the cargo.

[0201] The process shown in Figure 8 may be mainly performed during the boom raising and slewing motion section shown in Figure 7(C).

[0202] The shovel 100 excavates soil with the bucket 6 and begins the boom raising operation (step S801). When the height of the bucket 6 reaches the lower end of the measurement section, the load weight calculation unit 63 of the controller 30 begins calculating the weight of the soil and other materials loaded in the bucket 6.

[0203] Next, the sediment load processing unit 60 uses the area determination unit 62 to determine whether or not the piston member of the boom cylinder 7 is within the cushion area at the start of the boom raising operation (step S802).

[0204] In other words, the area determination unit 62 determines whether the state of the shovel 100 at the point when it is determined that the piston member of the boom cylinder 7 has reached the cushion area is the start of the boom raising operation.

[0205] In step S802, if it is determined that the piston member of the boom cylinder 7 is within the cushion area, the controller 30 waits until the piston member of the boom cylinder 7 moves outside the cushion area. Therefore, at this time, there are no measurement results to be adopted by the weight determination unit 67, and no measurement results are acquired.

[0206] In step S802, if it is determined that the piston member of the boom cylinder 7 is not within the cushion area, the area determination unit 62 determines whether or not the piston member of the boom cylinder 7 has reached the cushion area (step S803).

[0207] If it is determined in step S803 that the piston member of the boom cylinder 7 has reached the cushion area, the soil load processing unit 60 proceeds to step S809, which will be described later. On the other hand, if it is determined in step S803 that the piston member of the boom cylinder 7 has not reached the cushion area, the confirmation condition determination unit 61 determines whether the detection signal related to the raising operation of the boom 4 satisfies all of the multiple confirmation conditions, satisfies some of them, or does not satisfy any of the confirmation conditions.

[0208] In step S804, if the detection signal related to the lifting operation of boom 4 is determined to satisfy all of the multiple confirmation conditions, the soil load processing unit 60 confirms the soil weight calculated at this point as the measured soil weight (step S805). Here, since all confirmation conditions are met, the measurement accuracy of the confirmed soil weight is considered to be high.

[0209] Next, the sediment load processing unit 60 notifies the operator that the confirmation conditions have been met (step S806). Specifically, the sediment load processing unit 60 uses the information transmission unit 53 to display the measurement accuracy determined by the confirmation condition determination unit 61 and the weight of the sediment calculated by the load weight calculation unit 63 on the display device 40.

[0210] Next, the sediment load processing unit 60 determines whether the condition of the shovel 100 meets the measurement completion conditions (step S807).

[0211] The measurement completion condition is that, in the case of the shovel 100, the soil in bucket 6 is dumped onto the bed of the dump truck, and the weight of the soil in bucket 6 calculated by the load weight calculation unit 63 is added to the total load amount (total weight), which is the total weight of soil loaded onto the bed of the dump truck.

[0212] In step S807, if it is determined that the measurement termination conditions are met, the sediment load processing unit 60 terminates the process. In step S807, if it is determined that the measurement termination conditions are not met, the sediment load processing unit 60 returns to step S802.

[0213] In step S804, if the detection signal related to the lifting operation of boom 4 is determined to satisfy some of the multiple confirmation conditions, the sediment load processing unit 60 confirms the sediment weight calculated at this point as the measurement result of the sediment weight (step S808), and proceeds to step S806. Here, since some of the multiple confirmation conditions are satisfied, the measurement accuracy of the confirmed sediment weight is set to medium accuracy (moderate precision).

[0214] Furthermore, the sediment load processing unit 60 may compare the accuracy of the measured sediment weight it holds with the accuracy of the sediment weight determined in step S808, and determine the one with the higher accuracy as the measured sediment weight result.

[0215] Specifically, for example, the sediment load processing unit 60 may compare the number of determination conditions that were met when the weight of the sediment being held was determined with the number of determination conditions that were met when the weight of the sediment was determined in step S808, and determine the weight of the sediment with the larger number of determination conditions that are met as the measurement result.

[0216] Furthermore, in this embodiment, a priority is assigned to each determination condition in advance, and the sediment load processing unit 60 may, for example, compare the priority of the determination condition that was met when the held sediment weight was determined with the priority of the determination condition that was met when the sediment weight was determined in step S808. The sediment load processing unit 60 may determine the sediment weight with the higher priority of the met determination condition as the measurement result.

[0217] Furthermore, if the measured weight of the soil and sediment held by the soil and sediment processing unit 60 has changed by more than a predetermined range from the soil and sediment weight calculated in step S808, the soil and sediment load processing unit 60 may determine the new soil and sediment weight as the measured result.

[0218] In step S804, if it is determined that the detection signal related to the raising operation of boom 4 does not satisfy any of the multiple confirmation conditions, the soil load processing unit 60 returns to step S802.

[0219] In step S803, if it is determined that the piston member of the boom cylinder 7 has reached the cushion area, the area determination unit 62 determines whether or not the weight of the soil has been determined by the weight determination unit 67 (step S809).

[0220] In other words, the weight determination unit 67 determines whether the state of the shovel 100 satisfies some or more of the multiple determination conditions between the start of the excavation and loading operation and the determination in step S803 that the piston member of the boom cylinder 7 has reached the cushion area.

[0221] If it is determined in step S809 that the weight of the soil has been determined, the weight determination unit 67 adopts the already determined weight of the soil as the measurement result (step S810).

[0222] If it is determined in step S809 that the weight of the soil has not been determined, the adopted weight determination unit 67 adopts the weight of the soil calculated by the load weight calculation unit 63 at the time it is determined in step S803 that the piston member of the boom cylinder 7 has reached the cushion area as the measurement result (step S811). At this time, the measurement result of the adopted weight of soil will have low accuracy because the state of the shovel 100 satisfies all of the multiple determination conditions.

[0223] Thus, in this embodiment, when it is determined that the piston member of the boom cylinder 7 has reached the cushion area, the value obtained as the measurement result is made different depending on the state of the shovel 100 at the time of determination.

[0224] Specifically, in this embodiment, if the state of the shovel 100 at the time it is determined that the piston member of the boom cylinder 7 has reached the cushion area is the same as the start of the boom lifting operation (when the measurement of the weight of the soil and sand begins), then an empty value is output as the measurement result. In other words, in this embodiment, if the state of the work machine at the time it is determined that the piston member of the boom cylinder 7 has reached the cushion area is the same as the start of the attachment lifting operation, then no measurement result is obtained.

[0225] In this embodiment, this prevents the calculated soil weight from being finalized as a measurement result when an error occurs in the torque around the base of the boom 4 due to entering the cushion area. At this time, the soil load processing unit 60 may display a notification on the display device 40 or the like instructing that the boom 4 be lowered and the measurement be performed again.

[0226] Furthermore, in this embodiment, if the state of the shovel 100 at the time it is determined that the piston member of the boom cylinder 7 has reached the cushion area is after the excavation and loading operation has started and the weight of the soil has been determined, the already determined weight of soil is used in the measurement result and the determined weight of soil is not updated.

[0227] In other words, in this embodiment, if the state of the work machine at the time it is determined that the piston member of the boom cylinder 7 has reached the cushion area is after the lifting operation of the attachment has started and the measurement result of the weight of the object has been obtained, the already determined weight of the soil is adopted as the measurement result and the determined weight of the soil is not updated.

[0228] Therefore, according to this embodiment, it is possible to prevent the use of soil weight calculated under conditions where an error occurs in the torque around the base of the boom 4 due to entering the cushion area, thereby improving the accuracy of soil weight measurement.

[0229] Furthermore, in this embodiment, if the state of the shovel 100 at the time it is determined that the piston member of the boom cylinder 7 has reached the cushion area is such that the weight of the soil has not yet been determined since the start of the excavation and loading operation, the weight of the soil calculated by the load weight calculation unit 63 is adopted as the measurement result at the time it is determined that the piston member of the boom cylinder 7 has reached the cushion area, thereby forcibly determining the weight of the soil.

[0230] In other words, in this embodiment, if the state of the work machine at the time it is determined that the piston member of the boom cylinder 7 has reached the cushion area is after the lifting operation of the attachment has started and the measurement result of the weight of the object has not yet been obtained, then at the time of determination, the weight of the soil calculated by the load weight calculation unit 63 is adopted as the measurement result, and the weight of the soil is forcibly determined.

[0231] Therefore, according to this embodiment, it is possible to provide the maximum possible measurement area for measuring the weight of soil and sand in a state unaffected by reaching the cushion area.

[0232] Furthermore, in this embodiment, the weight of the soil that has not been affected by entering the cushion area is measured at the point when it reaches the cushion area, thus allowing the weight of soil removed by one cycle of excavation and loading to be maintained with a certain degree of accuracy.

[0233] In this embodiment, the weight of cargo such as soil and scrap materials loaded onto the beds of dump trucks and trailers can be measured with high accuracy, improving the accuracy of calculating the remaining load. Therefore, according to this embodiment, rework in weighing and adjustment is reduced, improving work efficiency at loading sites, and contributing to improved transportation efficiency and the suppression of road damage due to overloading. [Explanation of Symbols]

[0234] 100 Shovel 30 controllers 60. Sediment Load Processing Section 61 Determined condition judgment section 62 Area determination unit 63 Load Weight Calculation Unit 64 Maximum load detection unit 65. Additional Load Calculation Unit 66. Remaining Load Calculation Unit 67 Adopted weight determination section

Claims

1. A work machine having an attachment mounted on the main body of the work machine and a work tool provided at the tip of the attachment, A work machine having a control unit that, after an object has been held in the work tool, determines, based on detection information regarding the lifting operation of the attachment, that the piston member of the cylinder that operates the attachment has reached a predetermined range, and then determines that the measured weight result of the object obtained differs according to the state of the work machine at the time the determination is made.

2. The control unit, If, at the time the above determination is made, the state of the work machine is after the lifting operation of the attachment has started and the measurement result of the weight of the object has not yet been obtained, the work machine according to claim 1, wherein at the time the above determination is made, the weight of the object calculated based on the detection information related to the lifting operation of the attachment is obtained as the measurement result.

3. The control unit, The work machine according to claim 1, wherein, at the time the determination is made, the state of the work machine is after the lifting operation of the attachment has started and the measurement result of the weight of the object has been obtained, the obtained measurement result is obtained as the measurement result of the weight of the object at the time the determination is made.

4. The control unit, The work machine according to claim 1, wherein it determines whether the piston member of the cylinder has reached the predetermined range based on the amount of change in the cylinder pressure of the cylinder.

5. The control unit, The work machine according to claim 1, wherein if the state of the work machine at the time the above determination is made is the state at the start of the lifting operation of the attachment, the measurement result is not acquired.

6. The control unit, The working machine according to claim 5, wherein if the bottom pressure on the bottom side of the cylinder at the start of the lifting operation of the attachment is greater than or equal to a predetermined value, the state of the working machine is determined to be the state at the start of the lifting operation of the attachment.

7. A work machine having an attachment mounted on the main body of the work machine and a work tool provided at the tip of the attachment, After the work tool has held an object, if it is determined, based on detection information regarding the lifting operation of the attachment, that the piston member of the cylinder that operates the attachment has reached a predetermined range, the control unit has a control unit that adjusts the measurement result of the weight of the object obtained according to the state of the work machine at the time the determination is made. The control unit, If, at the time the above determination is made, the state of the work machine is after the lifting operation of the attachment has started and the measurement result of the weight of the object has not yet been obtained, then at the time the above determination is made, the weight of the object calculated based on the detection information related to the lifting operation of the attachment is obtained as the measurement result. If, at the time the above determination is made, the state of the work machine is after the lifting operation of the attachment has started and the measurement result of the weight of the object has been obtained, the obtained measurement result is taken as the measurement result of the weight of the object at the time the above determination is made. If the state of the work machine at the time the above determination is made is the state at the start of the lifting operation of the attachment, the work machine does not acquire the measurement result.

8. A control device for a work machine, comprising an attachment mounted on the main body of the work machine and a work tool provided at the tip of the attachment, The control device is A control device for a work machine, which, after an object has been held in the work tool, determines, based on detection information regarding the lifting movement of the attachment, that the piston member of the cylinder that operates the attachment has reached a predetermined range, and has a control unit that causes the measurement result of the weight of the object to be obtained to differ according to the state of the work machine at the time the determination is made.

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