Excavator, excavator control device, and excavator management system

Abstract

An excavator (100) having a lower travel body (1), an upper turning body (3) mounted on the lower travel body (1) so as to be capable of turning, and a controller (30) provided to the upper turning body (3). The controller (30) is configured so as to recognize the position of a dump truck (DT) and generate a target trajectory (TL) relating to a soil discharge operation. The target trajectory (TL) is typically set along the longitudinal direction of the dump truck (DT). Moreover, the target trajectory (TL) is typically set at a prescribed height along the bottom surface of the load bed (BD) of the dump truck (DT).

Description

[Technical Field]

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

[0002] Conventionally, a hydraulic excavator equipped with a semi-autonomous excavation control system is known (see Patent Document 1). This excavation control system is configured to autonomously perform a boom raising and swinging operation when a predetermined condition is satisfied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2011-514456 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-described excavation control system is based on the premise that the earth dumping operation is performed manually, and therefore the above-described excavation control system cannot improve the efficiency of the earth dumping operation.

[0005] Therefore, it is desirable to provide an excavator that can autonomously perform the earth dumping operation. [Means for solving the problem]

[0006] A shovel according to an embodiment of the present invention includes a lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, and a control device provided on the upper rotating body, wherein the control device is configured to recognize the position of a dump truck and generate a target trajectory for an earth-discharging operation, When the height of a newly formed load exceeds a predetermined height, the bucket is operated so as to level the top surface of the load with the back surface of the bucket. . [Effects of the Invention]

[0007] The above-described means provide a shovel that can autonomously perform earth dumping operations. [Brief explanation of the drawings]

[0008] [Figure 1A] FIG. 1 is a side view of a shovel according to an embodiment of the present invention. [Figure 1B] FIG. 1 is a top view of a shovel according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a hydraulic system mounted on a shovel. [Figure 3A] FIG. 1 is a diagram of a portion of the hydraulic system for operating the arm cylinder. [Figure 3B] FIG. 1 is a diagram of a portion of a hydraulic system relating to the operation of a swing hydraulic motor. [Figure 3C] FIG. 1 is a diagram of a portion of a hydraulic system for operating a boom cylinder. [Figure 3D] FIG. 1 is a diagram of a portion of a hydraulic system for operation of a bucket cylinder. [Figure 4] FIG. 2 is a functional block diagram of a controller. [Figure 5] FIG. 2 is a block diagram of an autonomous control function. [Figure 6] FIG. 2 is a block diagram of an autonomous control function. [Figure 7A] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 7B] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 7C] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 7D] FIG. 10 is a rear view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 8A] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 8B] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 8C] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 8D] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 8E] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 9A] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 9B] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 9C] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 9D] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 9E] FIG. 10 is a side view of the loading platform of the dump truck when the soil discharging operation is performed. [Figure 10] FIG. 10 is a block diagram showing another example of the configuration of the autonomous control function. [Figure 11] FIG. 1 is a diagram illustrating a configuration example of an electric operation system. [Figure 12] FIG. 1 is a schematic diagram illustrating a configuration example of a shovel management system. [Figure 13] FIG. 1 is an explanatory diagram illustrating the work flow of the excavator's "digging and loading operation." DETAILED DESCRIPTION OF THE INVENTION

[0009] First, a shovel 100 as an excavator according to an embodiment of the present invention will be described with reference to Figures 1A and 1B. Figure 1A is a side view of the shovel 100, and Figure 1B is a top view of the shovel 100.

[0010] In this embodiment, the lower traveling structure 1 of the excavator 100 includes a crawler 1C. The crawler 1C is driven by a traveling hydraulic motor 2M mounted on the lower traveling structure 1. Specifically, the crawler 1C includes a left crawler 1CL and a right crawler 1CR. The left crawler 1CL is driven by a left traveling hydraulic motor 2ML, and the right crawler 1CR is driven by a right traveling hydraulic motor 2MR.

[0011] An upper rotating body 3 is rotatably mounted on the lower traveling body 1 via a rotating mechanism 2. The rotating mechanism 2 is driven by a hydraulic motor 2A for rotation mounted on the upper rotating body 3. However, the hydraulic motor 2A for rotation may be a motor-generator for rotation as an electric actuator.

[0012] A boom 4 is attached to the upper rotating body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 is attached to the tip of the arm 5 as an end attachment. The boom 4, arm 5, and bucket 6 together make up an excavation attachment AT, which is an example of an attachment. The boom 4 is driven by a boom cylinder 7, the arm 5 is driven by an arm cylinder 8, and the bucket 6 is driven by a bucket cylinder 9.

[0013] The boom 4 is supported on the upper rotating body 3 so as to be able to rotate up and down. A boom angle sensor S1 is attached to the boom 4. The boom angle sensor S1 can detect a boom angle β1, which is the rotation angle of the boom 4. The boom angle β1 is, for example, the angle of ascent from the state in which the boom 4 is lowered to its lowest point. Therefore, the boom angle β1 is maximum when the boom 4 is raised to its highest point.

[0014] The arm 5 is rotatably supported relative to the boom 4. An arm angle sensor S2 is attached to the arm 5. The arm angle sensor S2 can detect an arm angle β2, which is the rotation angle of the arm 5. The arm angle β2 is, for example, the opening angle of the arm 5 from its most closed state. Therefore, the arm angle β2 is maximum when the arm 5 is most open.

[0015] The bucket 6 is rotatably supported by the arm 5. A bucket angle sensor S3 is attached to the bucket 6. The bucket angle sensor S3 can detect a bucket angle β3, which is the rotation angle of the bucket 6. The bucket angle β3 is the opening angle of the bucket 6 from its fully closed state. Therefore, the bucket angle β3 is maximum when the bucket 6 is fully opened.

[0016] 1A and 1B, the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 are each configured with a combination of an acceleration sensor and a gyro sensor. However, the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 may each be configured with only an acceleration sensor. Furthermore, the boom angle sensor S1 may be a stroke sensor attached to the boom cylinder 7, or may be a rotary encoder, a potentiometer, an inertial measurement unit, or the like. The same applies to the arm angle sensor S2 and the bucket angle sensor S3.

[0017] The upper rotating body 3 is provided with a cabin 10 as a driver's cab, and is equipped with one or more power sources. In this embodiment, the upper rotating body 3 is equipped with an engine 11 as a power source. The upper rotating body 3 is also equipped with an object detection device 70, an imaging device 80, a machine body tilt sensor S4, a swing angular velocity sensor S5, etc. Inside the cabin 10, an operation device 26, a controller 30, a display device D1, a sound output device D2, etc. For convenience, in this specification, the side of the upper rotating body 3 to which the excavating attachment AT is attached will be referred to as the front side, and the side to which the counterweight is attached will be referred to as the rear side.

[0018] The object detection device 70 is an example of a spatial recognition device, and is configured to detect objects present around the excavator 100. Examples of objects include people, animals, vehicles, construction machinery, buildings, walls, fences, holes, etc. The object detection device 70 is, for example, an ultrasonic sensor, a millimeter-wave radar, a stereo camera, a LIDAR, a distance image sensor, or an infrared sensor. In this embodiment, the object detection device 70 includes a front sensor 70F attached to the front end of the top surface of the cabin 10, a rear sensor 70B attached to the rear end of the top surface of the upper rotating body 3, a left sensor 70L attached to the left end of the top surface of the upper rotating body 3, and a right sensor 70R attached to the right end of the top surface of the upper rotating body 3. Each sensor is configured by a LIDAR.

[0019] The object detection device 70 may be configured to detect a predetermined object within a predetermined area set around the shovel 100. In other words, the object detection device 70 may be configured to be able to identify the type of object. For example, the object detection device 70 may be configured to be able to distinguish between a human and a non-human object. The object detection device 70 may be configured to calculate the distance from the object detection device 70 or the shovel 100 to the recognized object.

[0020] Then, if the spatial recognition device (object detection device 70) determines that a person is present within a predetermined distance range (predetermined range) from the excavator 100 before the actuator operates, the controller 30 may disable the actuator or put it into a slow speed state even if an operation command has already been output. The actuator is, for example, a hydraulic actuator or an electric actuator. The hydraulic actuator is, for example, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, etc.

[0021] Specifically, when it is determined that a person is present within the predetermined range, the controller 30 can disable the actuator by locking a switching valve (such as a gate lock valve) arranged in the pilot circuit. In the case of an electric control lever, the controller 30 can disable the actuator by disabling a signal from the controller 30 to the operation control valve. To put the actuator into a slow speed state, the controller 30 may, for example, reduce the signal from the controller 30 to the operation control valve. In this way, when it is determined that a person is present within the predetermined range, the controller 30 does not drive the actuator or drives it at a slow speed even if an operation command has already been generated. Furthermore, when it is determined that a person is present within the predetermined range while the operator is operating the control lever, the controller 30 may stop or slow down the operation of the actuator regardless of the operator's operation. Specifically, when it is determined that a person is present within the predetermined range, the controller 30 stops the actuator by locking a switching valve (such as a gate lock valve) arranged in the pilot circuit. When an operation control valve is used, the controller 30 can disable the actuator or put it into a very slow speed state by disabling a signal to the operation control valve or by outputting a deceleration command to the operation control valve. The operation control valve is configured to output a pilot pressure corresponding to a control command from the controller 30 and apply the pilot pressure to the pilot port of the corresponding control valve in the control valve unit 17. Furthermore, if the object detected by the object detection device 70 is a dump truck, the controller 30 does not need to execute stop control. In this case, the controller 30 may control the movement of the actuator to avoid the detected dump truck. In this way, the controller 30 can appropriately control the movement of the actuator based on the type of object detected.

[0022] The imaging device 80 is configured to capture images of the surroundings of the excavator 100. In this embodiment, the imaging device 80 includes a rear camera 80B attached to the rear end of the upper surface of the upper rotating body 3, a front camera 80F attached to the front end of the upper surface of the cabin 10, a left camera 80L attached to the left end of the upper surface of the upper rotating body 3, and a right camera 80R attached to the right end of the upper surface of the upper rotating body 3.

[0023] The rear camera 80B is positioned adjacent to the rear sensor 70B, the front camera 80F is positioned adjacent to the front sensor 70F, the left camera 80L is positioned adjacent to the left sensor 70L, and the right camera 80R is positioned adjacent to the right sensor 70R.

[0024] The image captured by the imaging device 80 is displayed on the display device D1. The imaging device 80 may be configured to display a viewpoint converted image such as an overhead image on the display device D1. The overhead image is generated by combining images output by the rear camera 80B, the left camera 80L, and the right camera 80R, for example.

[0025] The imaging device 80 may be used as the object detection device 70. In this case, the object detection device 70 may be omitted.

[0026] The machine body inclination sensor S4 is configured to detect the inclination of the upper rotating body 3 with respect to a predetermined plane. In this embodiment, the machine body inclination sensor S4 is an acceleration sensor that detects the inclination angle about the longitudinal axis and the lateral axis of the upper rotating body 3 with respect to a virtual horizontal plane. The longitudinal axis and the lateral axis of the upper rotating body 3 are, for example, perpendicular to each other and pass through the shovel center point, which is a point on the rotation axis of the shovel 100.

[0027] The rotation angular velocity sensor S5 is configured to detect the rotation angular velocity of the upper rotating body 3. In this embodiment, the rotation angular velocity sensor S5 is a gyro sensor. The rotation angular velocity sensor S5 may be a resolver, a rotary encoder, or the like. The rotation angular velocity sensor S5 may detect a rotation speed. The rotation speed may be calculated from the rotation angular velocity.

[0028] Hereinafter, the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine body inclination sensor S4, and the turning angular velocity sensor S5 will also be referred to as attitude detection devices.

[0029] The display device D1 is a device that displays information. The sound output device D2 is a device that outputs sound. The operation device 26 is a device that an operator uses to operate the actuator.

[0030] The controller 30 is a control device for controlling the shovel 100. In this embodiment, the controller 30 is configured as a computer including a CPU, a volatile storage device, a nonvolatile storage device, and the like. The controller 30 reads out programs corresponding to each function from the nonvolatile storage device, loads them into the volatile storage device, and causes the CPU to execute the corresponding processing. Each function includes, for example, a machine guidance function that guides (provides guidance for) the operator in manually operating the shovel 100, and a machine control function that automatically assists the operator in manually operating the shovel 100.

[0031] Next, a configuration example of a hydraulic system mounted on the shovel 100 will be described with reference to Fig. 2. Fig. 2 is a diagram showing a configuration example of a hydraulic system mounted on the shovel 100. In Fig. 2, mechanical power transmission lines, hydraulic oil lines, pilot lines, and electrical control lines are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively.

[0032] The hydraulic system of the excavator 100 mainly includes an engine 11, a regulator 13, a main pump 14, a pilot pump 15, a control valve unit 17, an operating device 26, a discharge pressure sensor 28, an operating pressure sensor 29, a controller 30, and the like.

[0033] In FIG. 2, the hydraulic system circulates hydraulic oil from a main pump 14 driven by an engine 11 through a center bypass line 40 or a parallel line 42 to a hydraulic oil tank.

[0034] The engine 11 is a drive source of the excavator 100. In this embodiment, the engine 11 is, for example, a diesel engine that operates to maintain a predetermined rotation speed. An output shaft of the engine 11 is connected to the input shafts of the main pump 14 and the pilot pump 15.

[0035] The main pump 14 is configured to supply hydraulic oil via a hydraulic oil line to the control valve unit 17. In this embodiment, the main pump 14 is a swash plate type variable displacement hydraulic pump.

[0036] The regulator 13 is configured to control the discharge rate (displacement volume) of the main pump 14. In this embodiment, the regulator 13 controls the discharge rate (displacement volume) of the main pump 14 by adjusting the tilt angle of the swash plate of the main pump 14 in response to a control command from the controller 30.

[0037] The pilot pump 15 is configured to supply hydraulic oil to hydraulic control devices including the operating device 26 via a pilot line. In this embodiment, the pilot pump 15 is a fixed displacement hydraulic pump. However, the pilot pump 15 may be omitted. In this case, the function of the pilot pump 15 may be realized by the main pump 14. That is, the main pump 14 may have a function of supplying hydraulic oil to the operating device 26 and the like after reducing the pressure of the hydraulic oil by a throttle or the like, in addition to the function of supplying hydraulic oil to the control valve unit 17.

[0038] The control valve unit 17 is configured to control the flow of hydraulic oil in the hydraulic system. In this embodiment, the control valve unit 17 includes control valves 171 to 176. The control valve 175 includes a control valve 175L and a control valve 175R, and the control valve 176 includes a control valve 176L and a control valve 176R. The control valve unit 17 can selectively supply hydraulic oil discharged from the main pump 14 to one or more hydraulic actuators via the control valves 171 to 176. The control valves 171 to 176 control the flow rate of hydraulic oil flowing from the main pump 14 to the hydraulic actuators and the flow rate of hydraulic oil flowing from the hydraulic actuators to a hydraulic oil tank. The hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left traveling hydraulic motor 2ML, a right traveling hydraulic motor 2MR, and a swing hydraulic motor 2A.

[0039] The operating device 26 is a device used by an operator to operate the actuators. The actuators include at least one of hydraulic actuators and electric actuators. In this embodiment, the operating device 26 supplies hydraulic oil discharged from the pilot pump 15 to the pilot ports of the corresponding control valves in the control valve unit 17 via pilot lines. The pressure of the hydraulic oil supplied to each pilot port (pilot pressure) corresponds to the operation direction and operation amount of the lever or pedal (not shown) of the operating device 26 corresponding to each hydraulic actuator. However, the operating device 26 may be an electric operating device instead of the hydraulic operating device described above. In this case, the control valves in the control valve unit 17 may be electromagnetic spool valves.

[0040] The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In this embodiment, the discharge pressure sensor 28 outputs the detected value to the controller 30.

[0041] The operation pressure sensor 29 is configured to detect the operation of the operation device 26 by the operator. In this embodiment, the operation pressure sensor 29 detects the operation direction and operation amount of the operation device 26 corresponding to each actuator in the form of pressure (operation pressure), and outputs the detected value as operation data to the controller 30. The operation of the operation device 26 may be detected using a sensor other than the operation pressure sensor.

[0042] The main pump 14 includes a left main pump 14L and a right main pump 14R. The left main pump 14L is configured to circulate hydraulic oil to a hydraulic oil tank via a left center bypass line 40L or a left parallel line 42L. The right main pump 14R is configured to circulate hydraulic oil to a hydraulic oil tank via a right center bypass line 40R or a right parallel line 42R.

[0043] The left center bypass line 40L is a hydraulic oil line that passes through control valves 171, 173, 175L, and 176L arranged in the control valve unit 17. The right center bypass line 40R is a hydraulic oil line that passes through control valves 172, 174, 175R, and 176R arranged in the control valve unit 17.

[0044] The control valve 171 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the left traveling hydraulic motor 2ML and to discharge the hydraulic oil discharged by the left traveling hydraulic motor 2ML to the hydraulic oil tank.

[0045] The control valve 172 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the right traveling hydraulic motor 2MR and to discharge the hydraulic oil discharged by the right traveling hydraulic motor 2MR to the hydraulic oil tank.

[0046] The control valve 173 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the swing hydraulic motor 2A and to discharge the hydraulic oil discharged by the swing hydraulic motor 2A to the hydraulic oil tank.

[0047] The control valve 174 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the bucket cylinder 9 and to discharge the hydraulic oil in the bucket cylinder 9 to the hydraulic oil tank.

[0048] The control valve 175L is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the boom cylinder 7. The control valve 175R is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the boom cylinder 7 and to discharge the hydraulic oil in the boom cylinder 7 to the hydraulic oil tank.

[0049] The control valve 176L is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the arm cylinder 8 and to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0050] The control valve 176R is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the arm cylinder 8 and to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

[0051] The left parallel conduit 42L is a hydraulic oil line that runs parallel to the left center bypass conduit 40L. The left parallel conduit 42L can supply hydraulic oil to a downstream control valve when the flow of hydraulic oil through the left center bypass conduit 40L is restricted or blocked by any of the control valves 171, 173, or 175L. The right parallel conduit 42R is a hydraulic oil line that runs parallel to the right center bypass conduit 40R. The right parallel conduit 42R can supply hydraulic oil to a downstream control valve when the flow of hydraulic oil through the right center bypass conduit 40R is restricted or blocked by any of the control valves 172, 174, or 175R.

[0052] The regulator 13 includes a left regulator 13L and a right regulator 13R. The left regulator 13L controls the discharge rate of the left main pump 14L by adjusting the tilt angle of the swash plate of the left main pump 14L in accordance with the discharge pressure of the left main pump 14L. Specifically, for example, the left regulator 13L adjusts the tilt angle of the swash plate of the left main pump 14L in accordance with an increase in the discharge pressure of the left main pump 14L to reduce the discharge rate. The same applies to the right regulator 13R. This is to prevent the absorption power (e.g., absorption horsepower) of the main pump 14, which is expressed as the product of the discharge pressure and the discharge rate, from exceeding the output power (e.g., output horsepower) of the engine 11.

[0053] The operating device 26 includes a left operating lever 26L, a right operating lever 26R, and a travel lever 26D. The travel lever 26D includes a left traveling lever 26DL and a right traveling lever 26DR.

[0054] The left operating lever 26L is used for swing operation and operation of the arm 5. When the left operating lever 26L is operated in the forward / backward direction, it uses the hydraulic oil discharged from the pilot pump 15 to apply a control pressure corresponding to the amount of lever operation to the pilot port of the control valve 176. When it is operated in the left / right direction, it uses the hydraulic oil discharged from the pilot pump 15 to apply a control pressure corresponding to the amount of lever operation to the pilot port of the control valve 173.

[0055] Specifically, when the left operating lever 26L is operated in the arm closing direction, it introduces hydraulic oil into the right pilot port of the control valve 176L and introduces hydraulic oil into the left pilot port of the control valve 176R. When the left operating lever 26L is operated in the arm opening direction, it introduces hydraulic oil into the left pilot port of the control valve 176L and introduces hydraulic oil into the right pilot port of the control valve 176R. When the left operating lever 26L is operated in the left turning direction, it introduces hydraulic oil into the left pilot port of the control valve 173, and when operated in the right turning direction, it introduces hydraulic oil into the right pilot port of the control valve 173.

[0056] The right operating lever 26R is used to operate the boom 4 and the bucket 6. When the right operating lever 26R is operated in the forward / backward direction, it uses the hydraulic oil discharged by the pilot pump 15 to apply a control pressure corresponding to the amount of lever operation to the pilot port of the control valve 175. When it is operated in the left / right direction, it uses the hydraulic oil discharged by the pilot pump 15 to apply a control pressure corresponding to the amount of lever operation to the pilot port of the control valve 174.

[0057] Specifically, when the right operating lever 26R is operated in the boom-lowering direction, it introduces hydraulic oil into the right pilot port of the control valve 175R. When the right operating lever 26R is operated in the boom-raising direction, it introduces hydraulic oil into the right pilot port of the control valve 175R and also introduces hydraulic oil into the left pilot port of the control valve 175R. When the right operating lever 26R is operated in the bucket-closing direction, it introduces hydraulic oil into the left pilot port of the control valve 174, and when operated in the bucket-opening direction, it introduces hydraulic oil into the right pilot port of the control valve 174.

[0058] The travel lever 26D is used to operate the crawler 1C. Specifically, the left travel lever 26DL is used to operate the left crawler 1CL. The left travel lever 26DL may be configured to operate in conjunction with the left travel pedal. When the left travel lever 26DL is operated in the forward / backward direction, it uses hydraulic oil discharged from the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the control valve 171. The right travel lever 26DR is used to operate the right crawler 1CR. The right travel lever 26DR may be configured to operate in conjunction with the right travel pedal. When the right travel lever 26DR is operated in the forward / backward direction, it uses hydraulic oil discharged from the pilot pump 15 to apply a control pressure corresponding to the lever operation amount to the pilot port of the control valve 172.

[0059] The discharge pressure sensor 28 includes a discharge pressure sensor 28L and a discharge pressure sensor 28R. The discharge pressure sensor 28L detects the discharge pressure of the left main pump 14L and outputs the detected value to the controller 30. The same applies to the discharge pressure sensor 28R.

[0060] The operation pressure sensor 29 includes operation pressure sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. The operation pressure sensor 29LA detects the details of the forward / backward operation of the left operation lever 26L by the operator in the form of pressure, and outputs the detected value to the controller 30. The details of the operation include, for example, the lever operation direction and the lever operation amount (lever operation angle), etc.

[0061] Similarly, operating pressure sensor 29LB detects, in the form of pressure, the operation of left operating lever 26L by the operator in the left-right direction, and outputs the detected value to controller 30. Operating pressure sensor 29RA detects, in the form of pressure, the operation of right operating lever 26R by the operator in the forward-backward direction, and outputs the detected value to controller 30. Operating pressure sensor 29RB detects, in the form of pressure, the operation of right operating lever 26R by the operator in the left-right direction, and outputs the detected value to controller 30. Operating pressure sensor 29DL detects, in the form of pressure, the operation of left traveling lever 26DL by the operator in the forward-backward direction, and outputs the detected value to controller 30. Operating pressure sensor 29DR detects, in the form of pressure, the operation of right traveling lever 26DR by the operator in the forward-backward direction, and outputs the detected value to controller 30.

[0062] The controller 30 receives the output of the operating pressure sensor 29 and outputs a control command to the regulator 13 as necessary to change the discharge rate of the main pump 14. The controller 30 also receives the output of the control pressure sensor 19 provided upstream of the orifice 18 and outputs a control command to the regulator 13 as necessary to change the discharge rate of the main pump 14. The orifice 18 includes a left orifice 18L and a right orifice 18R, and the control pressure sensor 19 includes a left control pressure sensor 19L and a right control pressure sensor 19R.

[0063] A left throttle 18L is disposed in the left center bypass pipe 40L between the hydraulic oil tank and the control valve 176L, which is located most downstream. Therefore, the flow of hydraulic oil discharged from the left main pump 14L is restricted by the left throttle 18L. The left throttle 18L generates a control pressure for controlling the left regulator 13L. The left control pressure sensor 19L detects this control pressure and outputs the detected value to the controller 30. The controller 30 controls the discharge rate of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L in accordance with this control pressure. The controller 30 decreases the discharge rate of the left main pump 14L as this control pressure increases, and increases the discharge rate of the left main pump 14L as this control pressure decreases. The discharge rate of the right main pump 14R is controlled in a similar manner.

[0064] Specifically, as shown in FIG. 2 , when the excavator 100 is in a standby state in which none of the hydraulic actuators are operated, the hydraulic oil discharged from the left main pump 14L passes through the left center bypass pipe 40L and reaches the left throttle 18L. The flow of hydraulic oil discharged from the left main pump 14L increases the control pressure generated upstream of the left throttle 18L. As a result, the controller 30 reduces the discharge rate of the left main pump 14L to the minimum allowable discharge rate, thereby suppressing pressure loss (pumping loss) that occurs when the hydraulic oil discharged from the left main pump 14L passes through the left center bypass pipe 40L. On the other hand, when any hydraulic actuator is operated, the hydraulic oil discharged from the left main pump 14L flows into the hydraulic actuator to be operated via the control valve corresponding to the hydraulic actuator to be operated. The flow of hydraulic oil discharged from the left main pump 14L reduces or eliminates the amount of hydraulic oil reaching the left throttle 18L, thereby lowering the control pressure generated upstream of the left throttle 18L. As a result, the controller 30 increases the discharge rate of the left main pump 14L, allowing sufficient hydraulic oil to flow into the hydraulic actuator to be operated, ensuring reliable drive of the hydraulic actuator. The controller 30 also controls the discharge rate of the right main pump 14R in a similar manner.

[0065] With the above-described configuration, the hydraulic system of Fig. 2 can suppress unnecessary energy consumption related to the main pump 14 in a standby state. The unnecessary energy consumption includes pumping loss caused by the hydraulic oil discharged from the main pump 14 in the center bypass pipe 40. Furthermore, when operating a hydraulic actuator, the hydraulic system of Fig. 2 can reliably supply necessary and sufficient hydraulic oil from the main pump 14 to the hydraulic actuator to be operated.

[0066] Next, with reference to Fig. 3A to Fig. 3D, a configuration for the controller 30 to automatically operate the actuators using the machine control function will be described. Fig. 3A to Fig. 3D are diagrams of a portion of the hydraulic system. Specifically, Fig. 3A is a diagram of a portion of the hydraulic system related to the operation of the arm cylinder 8, and Fig. 3B is a diagram of a portion of the hydraulic system related to the operation of the swing hydraulic motor 2A. Furthermore, Fig. 3C is a diagram of a portion of the hydraulic system related to the operation of the boom cylinder 7, and Fig. 3D is a diagram of a portion of the hydraulic system related to the operation of the bucket cylinder 9.

[0067] 3A to 3D, the hydraulic system includes a proportional valve 31, a shuttle valve 32, and a proportional valve 33. The proportional valve 31 includes proportional valves 31AL to 31DL and 31AR to 31DR, the shuttle valve 32 includes shuttle valves 32AL to 32DL and 32AR to 32DR, and the proportional valve 33 includes proportional valves 33AL to 33DL and 33AR to 33DR.

[0068] The proportional valve 31 is configured to function as a control valve for machine control. The proportional valve 31 is disposed in a pipe connecting the pilot pump 15 and the shuttle valve 32, and is configured to be able to change the flow path area of the pipe. In this embodiment, the proportional valve 31 operates in response to a control command output by the controller 30. Therefore, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17 via the proportional valve 31 and the shuttle valve 32, regardless of the operation of the operating device 26 by the operator.

[0069] The shuttle valve 32 has two inlet ports and one outlet port. One of the two inlet ports is connected to the operating device 26, and the other is connected to the proportional valve 31. The outlet port is connected to the pilot port of the corresponding control valve in the control valve unit 17. Therefore, the shuttle valve 32 can apply the higher of the pilot pressure generated by the operating device 26 or the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve.

[0070] The proportional valve 33 functions as a control valve for machine control, similar to the proportional valve 31. The proportional valve 33 is disposed in a pipe connecting the operating device 26 and the shuttle valve 32, and is configured so that the flow path area of the pipe can be changed. In this embodiment, the proportional valve 33 operates in response to a control command output by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic oil discharged by the operating device 26 and supply it to the pilot port of the corresponding control valve in the control valve unit 17 via the shuttle valve 32, regardless of the operation of the operating device 26 by the operator.

[0071] With this configuration, the controller 30 can operate the hydraulic actuator corresponding to a specific operating device 26 even when no operation is being performed on that specific operating device 26. Furthermore, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to that specific operating device 26 even when an operation is being performed on that specific operating device 26.

[0072] For example, as shown in FIG. 3A, the left operating lever 26L is used to operate the arm 5. Specifically, the left operating lever 26L uses hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure corresponding to its operation in the forward / backward direction to the pilot port of the control valve 176. More specifically, when the left operating lever 26L is operated in the arm closing direction (rearward), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R. Furthermore, when the left operating lever 26L is operated in the arm opening direction (forward), it applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R.

[0073] The left operating lever 26L is provided with a switch NS. In this embodiment, the switch NS is a push button switch. The operator can operate the left operating lever 26L with their hand while pressing the switch NS with their finger. The switch NS may be provided on the right operating lever 26R or at another position within the cabin 10.

[0074] The operation pressure sensor 29LA detects the operation of the left operation lever 26L in the forward and backward directions by the operator in the form of pressure, and outputs the detected value to the controller 30.

[0075] The proportional valve 31AL operates in response to a current command output by the controller 30. The proportional valve 31AL adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL and the shuttle valve 32AL. The proportional valve 31AR operates in response to a current command output by the controller 30. The proportional valve 31AR adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR and the shuttle valve 32AR. The proportional valve 31AL can adjust the pilot pressure so that the control valve 176L can be stopped at any valve position. The proportional valve 31AR can adjust the pilot pressure so that the control valve 176R can be stopped at any valve position.

[0076] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL and the shuttle valve 32AL, regardless of the arm closing operation by the operator. That is, the controller 30 can automatically close the arm 5. Furthermore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the proportional valve 31AR and the shuttle valve 32AR, regardless of the arm opening operation by the operator. That is, the controller 30 can automatically open the arm 5.

[0077] The proportional valve 33AL operates in response to a control command (current command) output by the controller 30. It reduces the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the left operating lever 26L, proportional valve 33AL, and shuttle valve 32AL. The proportional valve 33AR operates in response to a control command (current command) output by the controller 30. It reduces the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R via the left operating lever 26L, proportional valve 33AR, and shuttle valve 32AR. The proportional valves 33AL and 33AR are capable of adjusting the pilot pressure so that the control valves 176L and 176R can be stopped at any valve position.

[0078] With this configuration, even when the operator is performing an arm closing operation, the controller 30 can, as necessary, reduce the pilot pressure acting on the closing side pilot ports of the control valve 176 (the left pilot port of the control valve 176L and the right pilot port of the control valve 176R) to forcibly stop the closing operation of the arm 5. The same applies to the case where the opening operation of the arm 5 is forcibly stopped when the operator is performing an arm opening operation.

[0079] Alternatively, even when the operator is performing an arm closing operation, the controller 30 may control the proportional valve 31AR as necessary to increase the pilot pressure acting on the opening-side pilot ports of the control valve 176 (the right pilot port of the control valve 176L and the left pilot port of the control valve 176R) that are located opposite the closing-side pilot port of the control valve 176, thereby forcibly returning the control valve 176 to the neutral position, thereby forcibly stopping the closing operation of the arm 5. In this case, the proportional valve 33AL may be omitted. The same applies to the case where the opening operation of the arm 5 is forcibly stopped when the operator is performing an arm-opening operation.

[0080] 3B to 3D, the same applies to the case where the rotation operation of the upper rotating body 3 is forcibly stopped when the operator is performing a rotation operation, the case where the operation of the boom 4 is forcibly stopped when the operator is performing a boom-up operation or a boom-down operation, and the case where the operation of the bucket 6 is forcibly stopped when the operator is performing a bucket-closing operation or a bucket-opening operation. The same applies to the case where the traveling operation of the lower traveling body 1 is forcibly stopped when the operator is performing a traveling operation.

[0081] 3B, the left operating lever 26L is also used to operate the swing mechanism 2. Specifically, the left operating lever 26L uses hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure corresponding to operation in the left or right direction to the pilot port of the control valve 173. More specifically, when the left operating lever 26L is operated in the left swing direction (leftward), the left operating lever 26L applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 173. When the left operating lever 26L is operated in the right swing direction (rightward), the left operating lever 26L applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 173.

[0082] The operation pressure sensor 29LB detects the operation of the left operation lever 26L by the operator in the left and right directions in the form of pressure, and outputs the detected value to the controller 30.

[0083] The proportional valve 31BL operates in response to a current command output by the controller 30. The proportional valve 31BL adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31BL and shuttle valve 32BL. The proportional valve 31BR operates in response to a current command output by the controller 30. The proportional valve 31BR adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31BR and shuttle valve 32BR. The proportional valves 31BL and 31BR can adjust the pilot pressure so that the control valve 173 can be stopped at any valve position.

[0084] With this configuration, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31BL and the shuttle valve 32BL, regardless of the left rotation operation by the operator. That is, the controller 30 can automatically rotate the rotation mechanism 2 to the left. Furthermore, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31BR and the shuttle valve 32BR, regardless of the right rotation operation by the operator. That is, the controller 30 can automatically rotate the rotation mechanism 2 to the right.

[0085] 3C, the right operating lever 26R is used to operate the boom 4. Specifically, the right operating lever 26R uses hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure corresponding to its operation in the forward / backward direction to the pilot port of the control valve 175. More specifically, when the right operating lever 26R is operated in the boom-up direction (rearward), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. When the right operating lever 26R is operated in the boom-down direction (forward), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 175R.

[0086] The operation pressure sensor 29RA detects the operation of the right operation lever 26R in the forward and backward directions by the operator in the form of pressure, and outputs the detected value to the controller 30.

[0087] The proportional valve 31CL operates in response to a current command output by the controller 30. The proportional valve 31CL adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31CL and the shuttle valve 32CL. The proportional valve 31CR operates in response to a current command output by the controller 30. The proportional valve 31CR adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 175L and the right pilot port of the control valve 175R via the proportional valve 31CR and the shuttle valve 32CR. The proportional valve 31CL can adjust the pilot pressure so that the control valve 175L can be stopped at any valve position. The proportional valve 31CR can adjust the pilot pressure so that the control valve 175R can be stopped at any valve position.

[0088] With this configuration, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31CL and the shuttle valve 32CL, regardless of the boom-raising operation by the operator. That is, the controller 30 can automatically raise the boom 4. Furthermore, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31CR and the shuttle valve 32CR, regardless of the boom-lowering operation by the operator. That is, the controller 30 can automatically lower the boom 4.

[0089] 3D, the right operating lever 26R is also used to operate the bucket 6. Specifically, the right operating lever 26R uses hydraulic oil discharged from the pilot pump 15 to apply a pilot pressure corresponding to operation in the left or right direction to the pilot port of the control valve 174. More specifically, when the right operating lever 26R is operated in the bucket closing direction (leftward), the right operating lever 26R applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 174. When the right operating lever 26R is operated in the bucket opening direction (rightward), the right operating lever 26R applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 174.

[0090] The operation pressure sensor 29RB detects the operation of the right operation lever 26R in the left and right direction by the operator in the form of pressure, and outputs the detected value to the controller 30.

[0091] The proportional valve 31DL operates in response to a current command output by the controller 30. The proportional valve 31DL adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31DL and shuttle valve 32DL. The proportional valve 31DR operates in response to a current command output by the controller 30. The proportional valve 31DR adjusts the pilot pressure of hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31DR and shuttle valve 32DR. The proportional valves 31DL and 31DR can adjust the pilot pressure so that the control valve 174 can be stopped at any valve position.

[0092] With this configuration, controller 30 can supply hydraulic oil discharged from pilot pump 15 to the left pilot port of control valve 174 via proportional valve 31DL and shuttle valve 32DL, regardless of the bucket closing operation by the operator. In other words, controller 30 can automatically close bucket 6. Furthermore, controller 30 can supply hydraulic oil discharged from pilot pump 15 to the right pilot port of control valve 174 via proportional valve 31DR and shuttle valve 32DR, regardless of the bucket opening operation by the operator. In other words, controller 30 can automatically open bucket 6.

[0093] The excavator 100 may be configured to automatically move the lower traveling structure 1 forward and backward. In this case, the parts of the hydraulic system related to the operation of the left traveling hydraulic motor 2ML and the right traveling hydraulic motor 2MR may be configured in the same manner as the parts related to the operation of the boom cylinder 7, etc.

[0094] Next, the functions of the controller 30 will be described with reference to FIG. 4. FIG. 4 is a functional block diagram of the controller 30. In the example of FIG. 4, the controller 30 is configured to receive signals output from the attitude detection device, the operation device 26, the object detection device 70, the imaging device 80, the switch NS, etc., perform various calculations, and output control commands to the proportional valve 31, the display device D1, the sound output device D2, etc. The attitude detection device includes, for example, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body inclination sensor S4, and a swing angular velocity sensor S5. The controller 30 has a trajectory generation unit 30A and an autonomous control unit 30B as functional blocks. Each functional block may be configured as hardware or software.

[0095] The trajectory generating unit 30A is configured to generate a target trajectory, which is a trajectory that a predetermined portion of the shovel 100 follows when the shovel 100 is operated autonomously. The predetermined portion is, for example, the tip of the bucket 6 or a predetermined point on the back surface of the bucket 6. In this embodiment, the trajectory generating unit 30A generates a target trajectory that is used when the autonomous control unit 30B operates the shovel 100 autonomously. Specifically, the trajectory generating unit 30A generates the target trajectory based on the output of at least one of the object detection device 70 and the imaging device 80.

[0096] The autonomous control unit 30B is configured to autonomously operate the shovel 100. In this embodiment, the autonomous control unit 30B is configured to move a predetermined portion of the shovel 100 along the target trajectory generated by the trajectory generating unit 30A when a predetermined start condition is satisfied. Specifically, when the operating device 26 is operated with the switch NS pressed, the autonomous control unit 30B autonomously operates the shovel 100 so that a predetermined portion of the shovel 100 moves along the target trajectory. For example, when the left operating lever 26L is operated in the arm opening direction with the switch NS pressed, the autonomous control unit 30B autonomously operates the excavation attachment AT so that the toe of the bucket 6 moves along the target trajectory.

[0097] Next, an example of a function of the controller 30 to autonomously control the movement of the attachment (hereinafter referred to as "autonomous control function") will be described with reference to Figures 5 and 6. Figures 5 and 6 are block diagrams of the autonomous control function.

[0098] First, the controller 30 determines a target movement speed and a target movement direction based on the operation tendency, as shown in Fig. 5. The operation tendency is determined based on, for example, the lever operation amount. The target movement speed is a target value of the movement speed of the control reference point, and the target movement direction is a target value of the movement direction of the control reference point. The control reference point is, for example, the tip of the bucket 6, a predetermined point on the back of the bucket 6, or a predetermined point on the bucket pin (the connection between the arm 5 and the bucket 6). The control reference point is, for example, a predetermined point on the boom angle β 1、Arm angle β 2、 It is calculated based on the bucket angle β3 and the swing angle α1.

[0099] Thereafter, the controller 30 calculates the three-dimensional coordinates (Xer, Yer, Zer) of the control reference point after a unit time has elapsed based on the target movement speed, the target movement direction, and the three-dimensional coordinates (Xe, Ye, Ze) of the control reference point. The three-dimensional coordinates (Xer, Yer, Zer) of the control reference point after a unit time has elapsed are, for example, coordinates on the target trajectory. The unit time is, for example, a time corresponding to an integer multiple of the control period.

[0100] The target trajectory may be, for example, a target trajectory for an earth-discharging operation (earth-removing operation) performed in a loading operation that loads earth and sand into a dump truck. The earth-discharging operation includes an operation of dumping (unloading) the excavated material, such as earth and sand, held in the bucket 6 onto the bed of the dump truck. Typically, the earth-discharging operation is a combined operation that includes a bucket-opening operation and an arm-opening operation. In this case, the target trajectory may be calculated based on at least one of the shape of the dump truck (e.g., the length of the dump truck bed in the front-to-rear direction and the orientation of the bed), the shape of the load, such as earth and sand, already loaded on the bed of the dump truck, and the volume of the excavated material held in the bucket 6. Note that the shape of the dump truck, the shape of the load, and the volume of the excavated material held in the bucket 6 may be derived based on the output of at least one of the object detection device 70 and the imaging device 80, for example.

[0101] For example, the target trajectory is set so that when the material to be excavated taken into the bucket 6 is dumped onto the bed of the dump truck, the height of the load newly formed by the material to be excavated will be approximately constant. Specifically, the target trajectory is set so that a substantially rectangular parallelepiped load having a width Wt, a length Lt, and a height Ht will be formed.

[0102] The target trajectory is typically calculated before the dumping operation is started and is not changed until the dumping operation is completed. However, the target trajectory may be changed while the dumping operation is being performed. For example, the target trajectory may be adjusted to be lower if the height of the newly formed load is greater than the desired height. That is, the target trajectory is typically controlled by open-loop control, but may also be feedback-controlled according to the height of the newly formed load. The height of the newly formed load is calculated based on the output of at least one of the object detection device 70 and the imaging device 80, for example.

[0103] Thereafter, the controller 30 calculates a command value β related to the rotation of the boom 4, the arm 5, and the bucket 6 based on the calculated three-dimensional coordinates (Xer, Yer, Zer). 1r , β 2r , and β 3r and a command value α related to the rotation of the upper rotating body 3. 1r The command value β 1r represents the boom angle β1 when the control reference point can be aligned with the three-dimensional coordinates (Xer, Yer, Zer). Similarly, the command value β 2r represents the arm angle β2 when the control reference point can be aligned with the three-dimensional coordinates (Xer, Yer, Zer), and the command value β 3r represents the bucket angle β3 when the control reference point can be aligned with the three-dimensional coordinates (Xer, Yer, Zer), and the command value α 1r represents the turning angle α1 when the control reference point can be aligned with the three-dimensional coordinates (Xer, Yer, Zer).

[0104] Command value β for the rotation of bucket 6 3r may be changed during the soil releasing operation. For example, the command value β 3r may be adjusted to be smaller if the height of the newly formed load is greater than the desired height. 3r is typically controlled by open loop control, but may also be feedback controlled depending on the height of the newly formed load.

[0105] When the target trajectory for the soil releasing operation is calculated, typically, the command value α 1r is omitted because the earth releasing operation is typically performed with the rotation angle α1 fixed.

[0106] Thereafter, the controller 30 operates the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the swing hydraulic motor 2A so that the boom angle β1, the arm angle β2, the bucket angle β3, and the swing angle α1 become the generated command values β1r, β2r, β3r, and α1r, respectively, as shown in Fig. 6. The swing angle α1 is calculated based on, for example, the output of the swing angular velocity sensor S5 and the dimensions of each part of the excavator 100 that have been measured and input in advance.

[0107] Specifically, controller 30 generates a boom cylinder pilot pressure command corresponding to the difference Δβ1 between the current value of boom angle β1 and the command value β1r. Then, controller 30 outputs a control current corresponding to the boom cylinder pilot pressure command to boom control mechanism 31C. Boom control mechanism 31C is configured to apply a pilot pressure corresponding to the control current corresponding to the boom cylinder pilot pressure command to control valve 175, which serves as a boom control valve. Boom control mechanism 31C may be, for example, proportional valves 31CL and 31CR in FIG. 3C.

[0108] Thereafter, the control valve 175 receives the pilot pressure generated by the boom control mechanism 31C and causes the hydraulic oil discharged by the main pump 14 to flow into the boom cylinder 7 in a flow direction and at a flow rate corresponding to the pilot pressure.

[0109] At this time, controller 30 may generate a boom spool control command based on the amount of spool displacement of control valve 175 detected by boom spool displacement sensor S7. Boom spool displacement sensor S7 is a sensor that detects the amount of displacement of a spool that constitutes control valve 175. Controller 30 may then output a control current corresponding to the boom spool control command to boom control mechanism 31C. In this case, boom control mechanism 31C applies a pilot pressure to control valve 175 that corresponds to the control current corresponding to the boom spool control command.

[0110] The boom cylinder 7 extends and retracts by hydraulic oil supplied via a control valve 175. The boom angle sensor S1 detects a boom angle β1 of the boom 4 moved by the boom cylinder 7 that extends and retracts.

[0111] Thereafter, the controller 30 feeds back the boom angle β1 detected by the boom angle sensor S1 as the current value of the boom angle β1 to be used when generating a boom cylinder pilot pressure command.

[0112] While the above description relates to the operation of the boom 4 based on the command value β1r, it similarly applies to the operation of the arm 5 based on the command value β2r, the operation of the bucket 6 based on the command value β3r, and the swing operation of the upper swing structure 3 based on the command value α1r. The arm control mechanism 31A is configured to apply a pilot pressure corresponding to a control current corresponding to an arm cylinder pilot pressure command to a control valve 176 serving as an arm control valve. The arm control mechanism 31A may be, for example, the proportional valve 31AL and the proportional valve 31AR in FIG. 3A. The bucket control mechanism 31D is configured to apply a pilot pressure corresponding to a control current corresponding to a bucket cylinder pilot pressure command to a control valve 174 serving as a bucket control valve. The bucket control mechanism 31D may be, for example, the proportional valve 31DL and the proportional valve 31DR in FIG. 3D. The swing control mechanism 31B is configured to apply a pilot pressure corresponding to a control current corresponding to a swing hydraulic motor pilot pressure command to a control valve 173 serving as a swing control valve. 3B. The arm spool displacement sensor S8 is a sensor that detects the displacement amount of a spool that constitutes the control valve 176. The bucket spool displacement sensor S9 is a sensor that detects the displacement amount of a spool that constitutes the control valve 174. The swing spool displacement sensor S6 is a sensor that detects the displacement amount of a spool that constitutes the control valve 173.

[0113] As shown in FIG. 5, the controller 30 may use pump discharge rate derivation units CP1, CP2, CP3, and CP4 to derive the pump discharge rates from the command values β1r, β2r, β3r, and α1r. In this embodiment, the pump discharge rate derivation units CP1, CP2, CP3, and CP4 derive the pump discharge rates from the command values β1r, β2r, β3r, and α1r using a pre-registered lookup table or the like. The pump discharge rates derived by the pump discharge rate derivation units CP1, CP2, CP3, and CP4 are summed and input to the pump flow rate calculation unit as a total pump discharge rate. The pump flow rate calculation unit controls the discharge rate of the main pump 14 based on the input total pump discharge rate. In this embodiment, the pump flow rate calculation unit controls the discharge rate of the main pump 14 by changing the swash plate tilt angle of the main pump 14 in accordance with the total pump discharge rate.

[0114] In this way, the controller 30 can simultaneously control the opening of each of the control valve 175 as a boom control valve, the control valve 176 as an arm control valve, the control valve 174 as a bucket control valve, and the control valve 173 as a swing control valve, and control the discharge rate of the main pump 14. Therefore, the controller 30 can supply an appropriate amount of hydraulic oil to each of the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the swing hydraulic motor 2A.

[0115] The controller 30 also calculates three-dimensional coordinates (Xer, Yer, Zer) and a command value β 1r , β 2r , β 3r , and α 1rand determining the discharge rate of the main pump 14 constitute one control cycle, and autonomous control is performed by repeating this control cycle. Furthermore, the controller 30 can improve the accuracy of the autonomous control by feedback-controlling the control reference point based on the outputs of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the swing angular velocity sensor S5. Specifically, the controller 30 can improve the accuracy of the autonomous control by feedback-controlling the flow rates of the hydraulic oil flowing into the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the swing hydraulic motor 2A.

[0116] Furthermore, when performing autonomous control of the soil-discharging operation, the controller 30 may be configured to monitor the distance between the bucket 6 and the dump truck so that the bucket 6 and the dump truck do not come into contact with each other. For example, the controller 30 may stop the movement of the excavation attachment AT when it determines, based on the output of the attitude detection device and the object detection device 70, that the distance between each of one or more predetermined points on the back surface of the bucket 6 and the front panel of the dump truck has fallen below a predetermined value, or when it determines that the distance between the toe of the bucket 6 and the bottom surface of the bed of the dump truck has fallen below a predetermined value.

[0117] Next, an example of autonomous control related to the earth dumping operation will be described with reference to Fig. 7A to Fig. 7D. Fig. 7A to Fig. 7C are side views of the bed BD of the dump truck DT when the earth dumping operation is performed, and Fig. 7D is a rear view of the bed BD. Specifically, Fig. 7A is a side view of the bed BD immediately before the earth dumping operation is performed. Fig. 7B is a side view of the bed BD immediately after the first earth dumping operation is performed. Fig. 7C is a side view of the bed BD immediately after the second earth dumping operation is performed. Fig. 7D is a rear view of the bed BD immediately after the second earth dumping operation is performed.

[0118] For clarity, Figures 7A to 7C show the front panel FR and rear gate RG of the dump truck DT, but omit the left and right side gates. For clarity, Figure 7D shows the left and right side gates LSG and RSG, but omits the front panel FR and rear gate RG. Also, Figures 7B to 7D omit the overall image of the dump truck DT.

[0119] Specifically, Fig. 7A shows the state of the bed BD of the dump truck DT when no material to be excavated, such as earth and sand, has been loaded onto it. Fig. 7A also shows the bucket 6 as bucket 6a, which has been positioned above the bed BD by manual operation or autonomous control and has loaded the material to be excavated. Bucket 6a also shows the state of the bucket 6 when the boom-raising and swinging operation performed after the excavation operation has been completed. Point Pa represents the position of the toe of the bucket 6 when the boom-raising and swinging operation has been completed.

[0120] When the bed BD of the dump truck DT is recognized based on the output of at least one of the object detection device 70 and the imaging device 80, a release start point Ps1 and a release end point Pe1 are set. Then, a target trajectory TL is determined as a virtual line segment connecting the release start point Ps1 and the release end point Pe1. Then, the opening angle of the bucket 6 is calculated so as to correspond to the position of this target trajectory TL. As a result, boom raising control and bucket opening control are executed so that the tip of the bucket 6 follows the target trajectory TL, corresponding to the arm opening control that is started when the tip of the bucket 6 is at the release start point Ps1. Then, when the arm 5 becomes perpendicular to the bed BD, the boom raising control switches to boom lowering control. In other words, when the arm opening control is executed at a predetermined speed as master control, the boom control and bucket control are executed accordingly as slave controls. In this way, the movement of the tip of the bucket 6 is controlled so as to follow the target trajectory TL. Bucket opening control may be executed as master control. In this case, the arm control and boom control are executed as slave controls. At least one of the opening speed of the arm 5 and the opening speed of the bucket 6 may be changed based on at least one of the characteristics of soil and sand, learning data for each work environment, and the like.

[0121] The target trajectory TL1 for the first earth-releasing operation is an example of the target trajectory TL, and is represented as a virtual line segment connecting the earth-releasing start point Ps1 and the earth-releasing end point Pe1, which are located at a height H1 from the bottom surface of the loading platform BD.

[0122] The release start point Ps1 is the starting point of the target trajectory TL1. The release start point Ps1 is set at a position spaced a distance RS forward from the rear gate RG. The value of the distance RS is stored in advance in, for example, a nonvolatile storage device. The release start point Ps1 is also set to pass through the center of the width of the loading platform BD.

[0123] The release end point Pe1 is the end point of the target trajectory TL1. The release end point Pe1 is set at a position spaced a distance FS rearward from the front panel FR. The value of the distance FS is stored in advance in, for example, a nonvolatile storage device. The release end point Pe1 is also set to pass through the center of the width of the loading platform BD.

[0124] The length L1 of the target trajectory TL1, which is the distance between the release start point Ps1 and the release end point Pe1, is an example of the length Lt, and is the value obtained by subtracting the intervals RS and FS from the bed length Lb of the dump truck DT.

[0125] The height H1 is an example of the height Ht, and is calculated, for example, based on the volume of the material to be excavated held in the bucket 6a. Specifically, the height H1 is calculated so that the volume of a rectangular parallelepiped expressed by the product of the length Lt (L1), the height Ht (H1), and the width Wt is equal to the volume of the material to be excavated held in the bucket 6a. The width Wt is a value corresponding to the width of the bucket 6. The length Lt (L1) and the width Wt are calculated based on the output of at least one of the object detection device 70 and the imaging device 80. The length Lt (L1) and the width Wt may be stored in advance in a non-volatile memory device. The volume of the material to be excavated held in the bucket 6a is calculated, for example, based on the output of at least one of the object detection device 70 and the imaging device 80.

[0126] The controller 30 autonomously operates the excavation attachment AT so that the toe of the bucket 6, which serves as a control reference point, moves along the target trajectory TL1 calculated in this manner. The controller 30 also executes bucket opening control in accordance with the movement of the toe of the bucket 6 along the target trajectory TL1.

[0127] Bucket opening control is a control that changes the bucket angle β3 so that the height of the load (a rectangular parallelepiped extending along the target trajectory TL1) newly formed by the excavated material taken into the bucket 6 is maintained at height H1.

[0128] Controller 30 typically executes bucket opening control so that bucket angle β3 increases as the toe of bucket 6 approaches release end point Pe1. Controller 30 may take into consideration the characteristics of the material to be excavated, such as the viscosity of the soil, when determining bucket angle β3. The characteristics of the material to be excavated may be dynamically calculated based on the output of at least one of object detection device 70 and imaging device 80, or may be stored in advance in a non-volatile storage device.

[0129] Bucket 6b shows the state of the bucket 6 when the toe of the bucket 6 is located at the soil-release start point Ps1. The bucket angle β3 at this time is angle θ1. Bucket 6c shows the state of the bucket 6 when the toe of the bucket 6 is located at point P1 on the target trajectory TL1. The bucket angle β3 at this time is angle θ2 (>θ1). Bucket 6d shows the state of the bucket 6 when the toe of the bucket 6 is located at point P2 on the target trajectory TL1. The bucket angle β3 at this time is angle θ3 (>θ2). Bucket 6e shows the state of the bucket 6 when the toe of the bucket 6 is located at the soil-release end point Pe1. The bucket angle β3 at this time is angle θ4 (>θ3). Bucket 6f shows the state of the bucket 6 when the boom-lowering swing operation, which is executed after the soil-release operation, starts. Furthermore, point Pf represents the position of the toe of the bucket 6 when the boom-lowering swing operation starts.

[0130] 7A to 7D, the controller 30 executes bucket opening control so that the back surface BF of the bucket 6 becomes parallel to the front panel FR when the toe of the bucket 6 is positioned at the discharge end point Pe1, or so that the bucket angle β3 becomes larger than the angle θ4 when the back surface BF of the bucket 6 becomes parallel to the front panel FR. This is to more reliably prevent contact between the bucket 6 and the front panel FR.

[0131] Figure 7B shows the state of the loading platform BD immediately after the first dumping operation. Specifically, Figure 7B shows the shape of the load LD formed when the controller 30 executes bucket opening control while moving the toe of the bucket 6 along the target trajectory TL1, i.e., the shape of the load LD1 formed by the first dumping operation. The load LD1 has a shape that is approximately the same as a rectangular parallelepiped with a length L1, a width Wt, and a height H1. Figure 7B shows the shape of the load LD1 formed by the first dumping operation as a cross pattern.

[0132] The target trajectory TL2 for the second earth-releasing operation is an example of the target trajectory TL, and is represented as a virtual line segment connecting the earth-releasing start point Ps2 and the earth-releasing end point Pe2, which are located at a height H2 from the top surface of the load LD1.

[0133] The height of the upper surface of the load LD1 relative to the bottom surface of the loading platform BD is calculated, for example, based on the output of at least one of the object detection device 70 and the imaging device 80. The height of the upper surface of the load LD1 may be the height H1 calculated immediately before the first earth-releasing operation.

[0134] The release start point Ps2 is the starting point of the target trajectory TL2. The release start point Ps2 is set at a position spaced forward from the rear gate RG by a distance RS. The distance RS for the target trajectory TL2 may be a different value from the distance RS for the target trajectory TL1.

[0135] The release end point Pe2 is the end point of the target trajectory TL2. The release end point Pe2 is set at a position spaced a distance FS rearward from the front panel FR. The distance FS for the target trajectory TL2 may be a value different from the distance FS for the target trajectory TL2.

[0136] The length L2 of the target trajectory TL2, which is the distance between the release start point Ps2 and the release end point Pe2, is an example of the length Lt, and is the value obtained by subtracting the intervals RS and FS from the bed length Lb of the dump truck DT.

[0137] Height H2 is an example of height Ht, and is calculated, for example, based on the volume of the material to be excavated held in bucket 6 immediately before the second earth-discharging operation is performed. Specifically, height H2 is calculated so that the volume of a rectangular parallelepiped expressed as the product of length Lt (L2), height Ht (H2), and width Wt is equal to the volume of the material to be excavated held in bucket 6 immediately before the second earth-discharging operation is performed.

[0138] The controller 30 autonomously operates the excavation attachment AT so that the toe of the bucket 6 moves along the target trajectory TL2 calculated in this manner. The controller 30 also executes bucket opening control in accordance with the movement of the toe of the bucket 6 along the target trajectory TL2.

[0139] 7C and 7D show the state of the loading platform BD immediately after the second dumping operation. Specifically, FIGS. 7C and 7D show the shape of the load LD formed when the controller 30 executes bucket opening control while moving the toe of the bucket 6 along the target trajectory TL2, i.e., the combined shape of the load LD1 formed by the first dumping operation and the load LD2 formed by the second dumping operation. The load LD2 has a shape roughly equivalent to a rectangular parallelepiped with a length L2, a width Wt, and a height H2. In FIGS. 7C and 7D, the shape of the load LD2 formed by the second dumping operation is indicated by a diagonal line pattern sloping downward to the right.

[0140] The controller 30 similarly generates a target trajectory TL for the third and subsequent earth-discharging operations. Specifically, if the total weight of the material currently being excavated in the bucket 6 and the weight of the load LD already loaded in the bed BD of the dump truck DT is equal to or less than the maximum load capacity of the dump truck DT, the controller 30 generates a target trajectory TL for the next earth-discharging operation. On the other hand, if the total weight exceeds the maximum load capacity of the dump truck DT, the controller 30 does not calculate a target trajectory for the next earth-discharging operation. In other words, the controller 30 does not execute autonomous control for the next earth-discharging operation. This is because if the next earth-discharging operation is performed, the final weight of the load LD will exceed the maximum load capacity of the dump truck DT. In this case, the controller 30 may notify the operator of this using at least one of the display device D1 and the sound output device D2. The maximum load capacity of the dump truck DT may be a value input in advance or may be a value derived based on the output of at least one of the object detection device 70 and the imaging device 80.

[0141] Furthermore, the controller 30 may generate an imaginary line segment connecting the point Pa and the release start point Ps1 as an approach trajectory TLa, which is part of the target trajectory TL. The point Pa represents the position of the tip of the bucket 6 when the boom raising swing operation is completed.

[0142] Furthermore, the controller 30 may generate an imaginary line segment connecting the release end point Pe1 and point Pf as an escape trajectory TLw, which is another part of the target trajectory TL. Point Pf represents the toe position of the bucket 6 when the boom lowering swing operation starts.

[0143] The controller 30 may also be configured to set the end position of the boom-raising swing operation and the target trajectory TL for the earth-discharging operation between the left side gate LSG and the right side gate RSG. When the control reference point is set to the center of the bucket 6 in the left-right direction, the controller 30 may also be configured to set the target trajectory TL for the earth-discharging operation midway between the left side gate LSG and the right side gate RSG.

[0144] With the above configuration, the controller 30 can assist the operator in the earth dumping operation. Therefore, even if the operator of the shovel 100 is not skilled in the earth dumping operation, he or she can perform the earth dumping operation in the same way as a skilled operator. Therefore, the controller 30 can improve the work efficiency of the shovel 100. Furthermore, the controller 30 can prevent the occurrence of a situation in which, for example, an unskilled operator dumps excavated materials onto the bed BD of the dump truck DT from a high position, causing the excavated materials to spill out of the bed BD.

[0145] Next, another example of autonomous control related to the earth dumping operation will be described with reference to Fig. 8A to Fig. 8E. Fig. 8A to Fig. 8E are side views of the bed BD of the dump truck DT when the earth dumping operation is performed. Specifically, Fig. 8A is a side view of the bed BD immediately before the earth dumping operation is performed. Fig. 8B is a side view of the bed BD immediately after the first earth dumping operation is performed. Fig. 8C is a side view of the bed BD immediately after the second earth dumping operation is performed. Fig. 8D is a side view of the bed BD immediately after the third earth dumping operation is performed. Fig. 8E is a side view of the bed BD immediately after the fourth earth dumping operation is performed.

[0146] 8A to 8E show the front panel FR and rear gate RG of the dump truck DT, but omit the left and right side gates for clarity. Also, like in FIGS. 7B and 7C, in FIGS. 8A to 8E, the entire image of the dump truck DT is omitted.

[0147] Fig. 8A shows the loading platform BD of the dump truck DT in a state where no excavated material such as earth or sand has been loaded on it. The target trajectory TL1 for the first earth-discharging operation shown in Fig. 8A is an example of the target trajectory TL, and is represented as a virtual line segment connecting an earth-discharging start point Ps1 and an earth-discharging end point Pe1, which are located at a height H1 from the bottom surface of the loading platform BD.

[0148] Height H1 is an example of height Ht, and is calculated, for example, based on the volume of the material held in the bucket 6 immediately before the first earth-discharging operation is performed. Specifically, height H1 is calculated so that the volume of a rectangular parallelepiped expressed as the product of length Lt (L1), height Ht (H1), and width Wt is equal to the volume of the material held in the bucket 6 immediately before the first earth-discharging operation is performed. Width Wt is a value corresponding to the width of the bucket 6, and is stored in advance in, for example, a non-volatile storage device.

[0149] The controller 30 autonomously operates the excavation attachment AT so that the toe of the bucket 6, which serves as a control reference point, moves along the target trajectory TL1. The controller 30 also executes bucket opening control in accordance with the movement of the toe of the bucket 6 along the target trajectory TL1.

[0150] Fig. 8B shows the state of the loading platform BD immediately after the first earth-discharging operation has been performed. Specifically, Fig. 8B shows the shape of the load LD1 formed by the first earth-discharging operation in a cross pattern.

[0151] The target trajectory TL2 for the second earth-releasing operation is an example of the target trajectory TL, and is represented as a virtual line segment connecting the earth-releasing start point Ps2 and the earth-releasing end point Pe2, which are located at a height H2 from the top surface of the load LD1.

[0152] Height H2 is an example of height Ht, and is calculated, for example, based on the volume of the material to be excavated held in bucket 6 immediately before the second earth-discharging operation is performed. Specifically, height H2 is calculated so that the volume of a rectangular parallelepiped expressed as the product of length Lt (L2), height Ht (H2), and width Wt is equal to the volume of the material to be excavated held in bucket 6 immediately before the second earth-discharging operation is performed.

[0153] The controller 30 autonomously operates the excavation attachment AT so that the toe of the bucket 6 moves along the target trajectory TL2 calculated in this manner. The controller 30 also executes bucket opening control in accordance with the movement of the toe of the bucket 6 along the target trajectory TL2.

[0154] Fig. 8C shows the state of the loading platform BD immediately after the second earth-discharging operation is performed. Specifically, Fig. 8C shows the shape of the load LD2 formed by the second earth-discharging operation with a diagonal line pattern sloping downward to the right.

[0155] The target trajectory TL3 for the third earth-releasing operation is an example of the target trajectory TL, and is represented as a virtual line segment connecting the earth-releasing start point Ps3 and the earth-releasing end point Pe3, which are located at a height H3 from the top surface of the load LD2.

[0156] Height H3 is an example of height Ht, and is calculated, for example, based on the volume of the material to be excavated held in the bucket 6 immediately before the third earth-discharging operation is performed. Specifically, height H3 is calculated so that the sum of the volume of the rectangular parallelepiped expressed by the product of length Lt (L3), height Ht (H3), and width Wt, and the volume of space SP1 is equal to the volume of the material to be excavated held in the bucket 6 immediately before the third earth-discharging operation is performed.

[0157] The space SP1 is a space between the cargo LD already loaded on the loading platform BD and the rear gate RG, and is capable of accommodating an object to be excavated. The volume of the space SP1 is derived, for example, based on the output of at least one of the object detection device 70 and the imaging device 80. The volume of the space SP1 may be a value pre-stored in a non-volatile memory device.

[0158] The controller 30 autonomously operates the excavation attachment AT so that the toe of the bucket 6 moves along the target trajectory TL3 calculated in this manner. The controller 30 also executes bucket opening control in accordance with the movement of the toe of the bucket 6 along the target trajectory TL3.

[0159] Furthermore, when the toe of the bucket 6 reaches the release start point Ps3, the controller 30 executes bucket swing control before moving the toe of the bucket 6 along the target trajectory TL3.

[0160] The bucket swing control is a control for dropping a part of the material to be excavated that has been taken into the bucket 6 into the space SP1, thereby filling the space SP1 with the material to be excavated.

[0161] Specifically, the controller 30 causes a portion of the object being excavated that is being lifted by the bucket 6 to fly out of the bucket 6 by slightly opening and closing the bucket 6 one or more times, i.e., by slightly extending and contracting the bucket cylinder 9 one or more times.

[0162] The controller 30 may move at least one of the boom 4, the arm 5, and the bucket 6 one or more times to swing the bucket 6, thereby causing a portion of the object being excavated by the bucket 6 to fly out of the bucket 6.

[0163] In this embodiment, the controller 30 starts moving the toe of the bucket 6 along the target trajectory TL3 when the bucket 6 has been swung a predetermined number of times, regardless of whether the space SP1 has been filled with part of the material to be excavated that has been lifted by the bucket 6. However, the controller 30 may continue to swing the bucket 6 until it is confirmed that the space SP1 has been filled with part of the material to be excavated. In this case, the controller 30 may determine whether the space SP1 has been filled with part of the material to be excavated based on the output of at least one of the object detection device 70 and the imaging device 80.

[0164] Fig. 8D shows the state of the loading platform BD immediately after the third earth-discharging operation has been performed. Specifically, Fig. 8D shows the shape of the load LD3 formed by the third earth-discharging operation using a dot pattern.

[0165] The target trajectory TL4 for the fourth release operation is an example of the target trajectory TL, and is represented as an imaginary line segment connecting the release start point Ps4 and the release end point Pe4, which are located at a height H4 slightly lower than the top surface of the load LD3. Note that the height H4 is the height from the bottom surface of the loading platform BD.

[0166] Height H4 is an example of height Ht, and is calculated, for example, based on the height of the upper surface of load LD3. The fourth earth-discharging operation is performed to level the upper surface of load LD, which has already been loaded onto platform BD, with the back surface of bucket 6, and to drop some of the material to be excavated on top of load LD into space SP2 and fill space SP2 by pushing the back surface of bucket 6. Therefore, the fourth earth-discharging operation is performed when bucket 6 is empty, that is, when no material to be excavated has been taken into bucket 6.

[0167] The space SP2 is a space that can accommodate an object to be excavated, and is located between the load LD already loaded on the loading platform BD and the front panel FR.

[0168] Specifically, height H4 is set to a height that is a predetermined distance lower than the upper surface of the load LD3. Then, controller 30 autonomously operates excavation attachment AT so that the toe of bucket 6 moves along target trajectory TL4.

[0169] Fig. 8E shows the state of the loading platform BD immediately after the fourth earth-discharging operation has been performed. Specifically, Fig. 8E shows the shape of the load LD after the top surface has been leveled by the fourth earth-discharging operation and the space SP2 has been filled with the material to be excavated. Note that in the leveling operation, the control reference point may be switched from the tip of the bucket 6 to a predetermined point on the back surface of the bucket 6.

[0170] With the above configuration, the controller 30 can assist the operator in the earth dumping operation. Therefore, even if the operator of the shovel 100 is not skilled in the earth dumping operation, he or she can perform the earth dumping operation in the same way as a skilled operator. Therefore, the controller 30 can improve the work efficiency of the shovel 100.

[0171] Next, with reference to Fig. 9A to Fig. 9E, yet another example of autonomous control related to the earth dumping operation will be described. Fig. 9A to Fig. 9E are side views of the bed BD of the dump truck DT when the earth dumping operation is performed. Specifically, Fig. 9A is a side view of the bed BD immediately before the earth dumping operation is performed. Fig. 9B is a side view of the bed BD immediately after the first earth dumping operation is performed. Fig. 9C is a side view of the bed BD immediately after the second earth dumping operation is performed. Fig. 9D is a side view of the bed BD immediately after the third earth dumping operation is performed. Fig. 9E is a side view of the bed BD immediately after the fourth earth dumping operation is performed.

[0172] 9A to 9E show the front panel FR and rear gate RG of the dump truck DT, but omit the left and right side gates for clarity. Also, like Fig. 7B, Fig. 7C, and Fig. 8A to Fig. 8E, Fig. 9A to Fig. 9E omit the illustration of the entire image of the dump truck DT.

[0173] Fig. 9A shows the loading platform BD of the dump truck DT in a state where no excavated material such as earth or sand has been loaded on it. The target trajectory TL1 for the first earth-discharging operation shown in Fig. 9A is an example of the target trajectory TL, and is represented as a virtual line segment connecting an earth-discharging start point Ps1 and an earth-discharging end point Pe1, which are located at a height H1 from the bottom surface of the loading platform BD.

[0174] Height H1 is an example of height Ht, and is calculated, for example, based on the volume of the material held in the bucket 6 immediately before the first earth-discharging operation is performed. Specifically, height H1 is calculated so that the volume of a rectangular parallelepiped expressed as the product of length Lt (L1), height Ht (H1), and width Wt is equal to the volume of the material held in the bucket 6 immediately before the first earth-discharging operation is performed. Width Wt is a value corresponding to the width of the bucket 6, and is stored in advance in, for example, a non-volatile storage device.

[0175] The controller 30 autonomously operates the excavation attachment AT so that the toe of the bucket 6, which serves as a control reference point, moves along the target trajectory TL1. The controller 30 also executes bucket opening control in accordance with the movement of the toe of the bucket 6 along the target trajectory TL1.

[0176] Fig. 9B shows the state of the loading platform BD immediately after the first earth-discharging operation has been performed. Specifically, Fig. 9B shows the shape of the load LD1 formed by the first earth-discharging operation in a cross pattern.

[0177] The target trajectory TL2 for the second earth-releasing operation is an example of the target trajectory TL, and is represented as an imaginary line segment connecting the earth-releasing start point Ps2 and the earth-releasing end point Pe2, which are located at a height H2 slightly lower than the top surface of the load LD1. Note that the height H2 is the height from the bottom surface of the loading platform BD.

[0178] Height H2 is an example of height Ht, and is calculated, for example, based on the height of the upper surface of load LD1. The second earth-discharging operation is performed to load the excavated material taken into bucket 6 onto loading platform BD, level the upper surface of load LD1 already loaded onto loading platform BD with the back surface of bucket 6, and push part of the excavated material on top of load LD with the back surface of bucket 6, thereby dropping part of the excavated material into space SP3 and filling space SP3.

[0179] The space SP3 is a space that can accommodate an object to be excavated, and is located between the load LD1 already loaded on the loading platform BD and the front panel FR.

[0180] Specifically, height H2 is set to a height that is a predetermined distance lower than the top surface of the load LD1. Then, controller 30 autonomously operates excavation attachment AT so that the toe of bucket 6 moves along target trajectory TL2. That is, controller 30 breaks down the upper portion of load LD1 formed in the first dumping operation, which is the previous dumping operation, while forming a new layer of load LD2 with the newly loaded material to be excavated in the second dumping operation, which is the current dumping operation. Furthermore, controller 30 executes bucket opening control in accordance with the movement of the toe of bucket 6 along target trajectory TL2. In bucket opening control, controller 30 changes bucket angle β3 so that the height of the load newly formed by the material to be excavated taken into bucket 6 becomes the desired height. The desired height is typically determined based on the length of target trajectory TL2 and the volume of the material to be excavated taken into bucket 6.

[0181] Fig. 9C shows the state of the loading platform BD immediately after the second earth-discharging operation is performed. Specifically, Fig. 9C shows the shape of the load LD2 formed by the second earth-discharging operation with a diagonal line pattern sloping downward to the right.

[0182] The target trajectory TL3 for the third release operation is an example of the target trajectory TL, and is represented as an imaginary line segment connecting the release start point Ps3 and the release end point Pe3, which are located at a height H3 slightly lower than the top surface of the load LD2. Note that the height H3 is the height from the bottom surface of the loading platform BD.

[0183] Height H3 is an example of height Ht, and is calculated, for example, based on the height of the upper surface of load LD2. The third discharge operation is performed to load the excavated material taken into bucket 6 onto platform BD, level the upper surface of load LD2 already loaded onto platform BD with the back surface of bucket 6, and push part of the excavated material on top of load LD2 with the back surface of bucket 6, thereby dropping part of the excavated material into space SP4 and filling space SP4.

[0184] The space SP4 is a space that can accommodate an object to be excavated, and is located between the load LD already loaded on the loading platform BD and the front panel FR.

[0185] Specifically, height H3 is set to a height that is a predetermined distance lower than the upper surface of load LD2. Then, controller 30 autonomously operates excavation attachment AT so that the toe of bucket 6 moves along target trajectory TL3.

[0186] The controller 30 autonomously operates the excavation attachment AT so that the toe of the bucket 6 moves along the target trajectory TL3 calculated in this manner. The controller 30 also executes bucket opening control in accordance with the movement of the toe of the bucket 6 along the target trajectory TL3.

[0187] Furthermore, when the toe of the bucket 6 reaches the release start point Ps3, the controller 30 executes bucket swing control before moving the toe of the bucket 6 along the target trajectory TL3.

[0188] The bucket swing control is a control for dropping a part of the material to be excavated that has been taken into the bucket 6 into the space SP5, thereby filling the space SP5 with the material to be excavated.

[0189] The space SP5 is a space that can accommodate objects to be excavated and is located between the cargo LD that has already been loaded on the loading platform BD and the rear gate RG.

[0190] Specifically, the controller 30 causes a portion of the object being excavated that is being lifted by the bucket 6 to fly out of the bucket 6 by slightly opening and closing the bucket 6 one or more times, i.e., by slightly extending and contracting the bucket cylinder 9 one or more times.

[0191] The controller 30 may move at least one of the boom 4, the arm 5, and the bucket 6 one or more times to swing the bucket 6, thereby causing a portion of the object being excavated by the bucket 6 to fly out of the bucket 6.

[0192] In this embodiment, the controller 30 starts moving the toe of the bucket 6 along the target trajectory TL3 when the bucket 6 has been swung a predetermined number of times, regardless of whether the space SP5 has been filled with part of the material to be excavated that had been taken into the bucket 6. However, the controller 30 may continue to swing the bucket 6 until it is confirmed that the space SP5 has been filled with part of the material to be excavated. In this case, the controller 30 may determine whether the space SP1 has been filled with part of the material to be excavated based on the output of at least one of the object detection device 70 and the imaging device 80.

[0193] Fig. 9D shows the state of the loading platform BD immediately after the third earth-discharging operation has been performed. Specifically, Fig. 9D shows the shape of the load LD3 formed by the third earth-discharging operation using a dot pattern.

[0194] The target trajectory TL4 for the fourth release operation is an example of the target trajectory TL, and is represented as an imaginary line segment connecting the release start point Ps4 and the release end point Pe4, which are located at a height H4 slightly lower than the top surface of the load LD3. Note that the height H4 is the height from the bottom surface of the loading platform BD.

[0195] Height H4 is an example of height Ht, and is calculated, for example, based on the height of the upper surface of load LD3. The fourth earth-discharging operation is performed to level the upper surface of load LD3, which has already been loaded onto platform BD, with the back surface of bucket 6, and to drop part of the material to be excavated on top of load LD3 into space SP6 and fill space SP6 by pushing the back surface of bucket 6. Therefore, the fourth earth-discharging operation is performed when bucket 6 is empty, that is, when no material to be excavated has been taken into bucket 6.

[0196] The space SP6 is a space that can accommodate an object to be excavated, and is located between the load LD already loaded on the loading platform BD and the front panel FR.

[0197] Specifically, height H4 is set to a height that is a predetermined distance lower than the upper surface of the load LD3. Then, controller 30 autonomously operates excavation attachment AT so that the toe of bucket 6 moves along target trajectory TL4.

[0198] Fig. 9E shows the state of the loading platform BD immediately after the fourth earth-discharging operation has been performed. Specifically, Fig. 9E shows the shape of the load LD after the top surface has been leveled by the fourth earth-discharging operation and the space SP6 has been filled with the material to be excavated. Note that in the leveling operation, the control reference point may be switched from the tip of the bucket 6 to a predetermined point on the back surface of the bucket 6.

[0199] With the above configuration, the controller 30 can assist the operator in the earth dumping operation. Therefore, even if the operator of the shovel 100 is not skilled in the earth dumping operation, he or she can perform the earth dumping operation in the same way as a skilled operator. Therefore, the controller 30 can improve the work efficiency of the shovel 100.

[0200] As described above, the excavator 100 according to an embodiment of the present invention has the lower traveling body 1, the upper rotating body 3 rotatably mounted on the lower traveling body 1, and the controller 30 as a control device provided on the upper rotating body 3. The controller 30 is configured to recognize the position of the dump truck DT and generate a target trajectory TL for the earth dumping operation. With this configuration, the excavator 100 can autonomously perform the earth dumping operation.

[0201] The target trajectory TL is preferably set along the front-rear direction of the dump truck DT. The target trajectory TL is also set at a predetermined height along the bottom surface of the bed BD of the dump truck DT. With this configuration, the controller 30 can efficiently dump the material to be excavated taken into the bucket 6 onto the bed BD of the dump truck DT.

[0202] The controller 30 is preferably configured to set the bucket angle β3 corresponding to each point on the target trajectory TL. With this configuration, the controller 30 can make the height of the load LD loaded on the bed BD of the dump truck DT uniform.

[0203] The controller 30 may be configured to control the bucket angle β3 based on the shape of the load LD loaded on the bed BD of the dump truck DT. With this configuration, the controller 30 can make the height of the load LD loaded on the bed BD of the dump truck DT more uniform.

[0204] The controller 30 is preferably configured to detect the distance between the back surface of the bucket 6 and the dump truck DT. With this configuration, the controller 30 can prevent the bucket 6 from coming into contact with the dump truck DT when executing autonomous control related to the soil-discharging operation.

[0205] Here, the workflow of the "digging and loading operation" of the shovel 100 will be described with reference to Fig. 13. Fig. 13 is an explanatory diagram for explaining the workflow of the "digging and loading operation" of the shovel 100.

[0206] Figures 13(A) to 13(D) show the state in which the excavation operation is being performed. The section in which the excavation operation is performed is called the excavation operation section. The excavation operation is divided into the first half of the excavation operation shown in Figures 13(A) and 13(B) and the second half of the excavation operation shown in Figures 13(C) and 13(D).

[0207] As shown in Fig. 13(A), controller 30 positions the tip of bucket 6 so that the tip is at a desired height relative to the excavation target (earth and sand in this example), and then closes arm 5 from the open state shown in Fig. 13(A) until arm 5 becomes approximately perpendicular to the ground surface as shown in Fig. 13(B). This operation excavates earth and sand to a certain depth, and the earth and sand are raked up by the time arm 5 becomes approximately perpendicular to the ground surface. The above operation is called the first half of the excavation operation, and this operation section is called the first half of the excavation operation section.

[0208] Thereafter, as shown in FIG. 13(C), the controller 30 further closes the arm 5 to cause the bucket 6 to further scrape up earth and sand. Then, as shown in FIG. 13(D), the controller 30 closes the bucket 6 until the upper edge is approximately horizontal, and stores the scraped up earth and sand into the bucket 6. The controller 30 also raises the boom 4 to raise the bucket 6 to the position shown in FIG. 13(D). The above operation is called the latter half of the excavation operation, and this operation section is called the latter half of the excavation operation section. The operation in FIG. 13(C) may be a combined operation of the arm 5 and the bucket 6.

[0209] Next, with the upper edge of the bucket 6 held approximately horizontal, the controller 30 raises the boom 4 until the bottom of the bucket 6 is at a desired height from the ground, as shown in Figure 13(E). The desired height is, for example, a height equal to or greater than the height of the rear gate RG of the dump truck DT. Following or simultaneously with this operation, the controller 30 rotates the upper rotating body 3 as shown by the arrow, and moves the bucket 6 to a position from which soil will be discharged.

[0210] After that, when the controller 30 completes the boom raising and swinging operation, it then opens the arm 5 and the bucket 6 as shown in Fig. 13(F) and discharges the soil in the bucket 6 into the bed BD of the dump truck DT. In this soil discharging operation (dumping operation), the controller 30 may open only the bucket 6 to discharge the soil.

[0211] After completing the dumping operation, the controller 30 then rotates the upper rotating body 3 as shown by the arrow in Figure 13(G), and moves the bucket 6 to directly above the excavation position. At this time, the controller 30 lowers the boom 4 simultaneously with the rotation, and lowers the bucket 6 to a desired height above the excavation target. Thereafter, the controller 30 lowers the bucket 6 to the desired height as shown in Figure 13(A), and performs the excavation operation again.

[0212] The target trajectory TL may be set for each of the excavation operation section, the boom-raising swing operation section, the dumping operation section, and the boom-lowering swing operation section according to the progress of the work. For example, the controller 30 may set a target trajectory TL for the excavation operation section and a target trajectory TL for the dumping operation section, calculate a target trajectory TL for the boom-raising swing operation section so as to connect the start point of the dumping operation section and the end point of the excavation operation section, and calculate a target trajectory TL for the boom-lowering swing operation section so as to connect the start point of the excavation operation section and the end point of the dumping operation section.

[0213] The target trajectory TL in the dumping operation section is set between the release start point Ps1 and the release end point Pe1 based on the position of the bed BD of the dump truck DT recognized as described above. Then, the target trajectory TL in the dumping operation section is updated every time a dumping operation is performed as described above.

[0214] The target trajectory TL in the excavation operation section is set between the excavation start position and the excavation end position. The target trajectory TL in the excavation operation section is set based on the soil shape (such as the shape of the terrain, the shape of the mound, or the shape of the temporarily stored pile of soil) each time an excavation operation is performed. The controller 30 may calculate the soil shape based on the trajectory of the bucket tip, or may calculate the soil shape based on the detection value of a device capable of detecting the surface shape of the soil, such as the object detection device 70 or the imaging device 80. In this way, the target trajectory TL in the excavation operation section is updated in accordance with an update of the soil shape each time an excavation operation is performed. Furthermore, the controller 30 may set the design surface used during finish excavation as the target trajectory TL in the excavation operation section. The object detection device 70, the imaging device 80, or the like used to acquire the soil shape may be installed independently of the excavator 100. Specifically, the object detection device 70, the imaging device 80, or the like may be attached to an aerial photography multicopter or a steel tower installed at the work site. The controller 30 may acquire information about the shape of the soil at the work site based on an image showing the state of the work site as viewed from above. The target trajectory TL in the excavation operation section may be calculated taking into consideration the shape of the bucket 6, soil characteristics, etc. The target trajectory TL in the excavation operation section may be calculated using reinforcement learning (machine learning) based on the soil shape before excavation and a target construction surface (design surface). When reinforcement learning is used, fuel consumption, work time, etc. may be set as the reward.

[0215] The target trajectory TL in the boom lowering swing operation section is set between the discharge end point Pe1 or the boom lowering swing start position (for example, point Pf in FIG. 7A) set above the bed BD of the dump truck DT and the excavation start position. Here, when the target trajectory TL in the boom lowering swing operation section is set between the discharge end point Pe1 and the excavation start position, it may include the escape trajectory TLw.

[0216] The target trajectory TL in the boom raising swing operation section is set between the earth-discharging start point Ps1 or the boom raising swing end position (for example, point Pa in FIG. 7A) set above the loading platform BD and the excavation end position. Here, when the target trajectory TL in the boom raising swing operation section is set between the excavation end position and the earth-discharging start point Ps1, it may include the approach trajectory TLa.

[0217] In this way, the controller 30 proceeds with the "digging and loading operation" by repeating a cycle consisting of "first half excavation operation," "second half excavation operation," "boom raising and swinging operation," "dumping operation," and "boom lowering and swinging operation."

[0218] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions may be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, features described separately may be combined unless technical contradictions arise.

[0219] For example, the excavator 100 may execute an autonomous control function as described below to autonomously perform a composite operation such as an earth dumping operation. FIG. 10 is a block diagram showing a configuration example of the autonomous control function. In the example of FIG. 10, the controller 30 has function blocks FA to FP and F1 to F6 related to the execution of autonomous control. The function blocks may be configured with software, may be configured with hardware, or may be configured with a combination of software and hardware.

[0220] The function block FA is configured to measure the loading platform of the dump truck DT. In the example of Fig. 10, the function block FA measures the loading platform of the dump truck DT based on an image captured by an imaging device 80 serving as a surroundings monitoring device. The surroundings monitoring device may be the object detection device 70.

[0221] The function block FB is configured to calculate the height of the load. In the example of Fig. 10, the function block FB calculates the height of the load formed by the excavated material taken into the bucket 6 when the excavated material is dumped onto the bed of the dump truck DT, based on the image captured by the imaging device 80.

[0222] The function block FC is configured to determine the presence or absence of various abnormalities. In the example of Fig. 10, the function block FC is configured to determine the presence or absence of an abnormality in the imaging device 80 based on an image captured by the imaging device 80. When the function block FC determines that the state of the imaging device 80 is abnormal, it outputs a command to a function block F4 (described later) to slow down or stop the movement of the excavator 100.

[0223] The function block FD is configured to detect the dump truck DT. In the example of Fig. 10, the function block FD detects the dump truck DT based on an image captured by the imaging device 80.

[0224] The function block FE is configured to derive the maximum load capacity of the dump truck DT detected by the function block FD. In the example of Fig. 10, the function block FE derives the maximum load capacity of the dump truck DT based on an image captured by the imaging device 80. The function block FE derives the maximum load capacity of the dump truck DT, for example, by identifying whether the dump truck DT is a 10-ton truck.

[0225] The function block FF is configured to determine the state of the boom 4. In the example of Fig. 10, the function block FF determines whether the boom 4 has risen to a height where the bucket 6, which has taken in the object to be excavated, is separated from the ground. This is to detect that the excavation operation has ended.

[0226] Specifically, the function block FF determines whether the boom 4 has risen to a height at which the bucket 6, which has taken in the material to be excavated, is clear of the ground, based on the current toe position of the bucket 6 calculated by a function block F2 described below. The function block FF may also determine whether the boom 4 has risen to a height at which the bucket 6, which has taken in the material to be excavated, is clear of the ground, based on an image captured by the imaging device 80.

[0227] Function block FG is configured to calculate the weight of the material to be excavated that has been taken into the bucket 6. In the example of FIG. 10 , when function block FF determines that the boom 4 has risen to a height at which the bucket 6, which has taken in the material to be excavated, is clear of the ground, function block FG calculates the weight of the material to be excavated that has been taken into the bucket 6 based on the output of cylinder pressure sensor S10. Cylinder pressure sensor S10 includes at least one of, for example, a boom bottom pressure sensor that detects a boom bottom pressure that is the pressure of hydraulic oil in a bottom-side oil chamber of boom cylinder 7, a boom rod pressure sensor that detects a boom rod pressure that is the pressure of hydraulic oil in a rod-side oil chamber of boom cylinder 7, an arm bottom pressure sensor that detects an arm bottom pressure that is the pressure of hydraulic oil in a bottom-side oil chamber of arm cylinder 8, an arm rod pressure sensor that detects an arm rod pressure that is the pressure of hydraulic oil in a rod-side oil chamber of arm cylinder 8, a bucket bottom pressure sensor that detects a bucket bottom pressure that is the pressure of hydraulic oil in a bottom-side oil chamber of bucket cylinder 9, and a bucket rod pressure sensor that detects a bucket rod pressure that is the pressure of hydraulic oil in a rod-side oil chamber of bucket cylinder 9. The function block FG may calculate the weight of the object to be excavated taken into the bucket 6 based on the attitude of the excavation attachment AT calculated by a function block F2 described below and the output of the cylinder pressure sensor S10.

[0228] The function block FH is configured to calculate the total weight of the materials to be excavated that have been loaded onto the dump truck DT. In the example of Fig. 10, the function block FH calculates the total weight of the materials to be excavated that have already been loaded onto the bed of the dump truck DT by accumulating the weights of the materials to be excavated by each excavation operation that have been calculated by the function block FG.

[0229] The function block FI is configured to calculate the remaining loading weight. In the example of Fig. 10, the function block FI calculates the remaining loading weight by subtracting the total weight of the materials to be excavated calculated by the function block FH from the maximum loading capacity calculated by the function block FE. For example, if the maximum loading capacity is 10 tons and the total weight of the materials to be excavated already loaded on the bed of the dump truck DT is 6 tons, the function block FH calculates the remaining loading weight as 4 tons.

[0230] The function block FJ is configured to acquire a target excavation weight, which is the weight of the material to be loaded into the bucket 6 in the next excavation operation, and to limit the acquired value as necessary. In the example of FIG. 10, the function block FJ reads and acquires the maximum excavation weight, which is the maximum amount of material that can be excavated in one excavation operation, from a non-volatile storage device. Then, if the remaining loading weight calculated by the function block FI is greater than the maximum excavation weight, the function block FJ limits the target excavation weight to the maximum excavation weight. For example, if the remaining loading weight is 4 tons but the maximum excavation weight is 3 tons, the function block FJ outputs 3 tons as the target excavation weight. Note that the maximum excavation weight may be a value that is dynamically input or calculated.

[0231] The function block FK is configured to calculate a target excavation volume. In the example of FIG. 10, the function block FK calculates the target excavation volume based on the target excavation weight output by the function block FJ and soil information input via the input device 43. The input device 43 is configured to allow an operator to input various information to the controller 30. The input device 43 is, for example, at least one of a touch panel, a microphone, a knob switch, and a membrane switch installed in the cabin 10. The soil information is, for example, information regarding the density or hardness of the material to be excavated. The soil information may be information pre-stored in a non-volatile memory device. The function block FK calculates the target excavation volume based on, for example, the target excavation weight and the density of the material to be excavated. For example, the function block FK calculates the target excavation volume corresponding to a target excavation weight of 3 tons. Basically, even if the target excavation weight is constant (for example, 3 tons), the smaller the density of the material to be excavated, the larger the target excavation volume.

[0232] The function block FL is configured to limit the target excavation volume. In the example of FIG. 10, if the target excavation volume calculated by the function block FK is larger than the maximum excavation volume, the function block FL limits the target excavation volume to the maximum excavation volume. For example, if the target excavation volume is 3 cubic meters but the maximum excavation volume is 2 cubic meters, the function block FL outputs 2 cubic meters as the target excavation volume. In this way, the controller 30 limits the target excavation volume as necessary to prevent the material taken into the bucket 6 from spilling out during subsequent swing operations, etc. Note that the maximum excavation volume may be a value that is dynamically input or calculated.

[0233] The function block F1 is configured to generate a target trajectory. In the example of FIG. 10 , the function block F1 generates a trajectory that the toe of the bucket 6 should follow during the earth-discharging operation as a target trajectory, based on information about earth-discharging input via the input device 43, the shape of the bed of the dump truck DT measured by the function block FA, and the height of the load calculated by the function block FB. The information about earth-discharging is, for example, information about a predetermined earth-discharging start point and earth-discharging end point. The information about the earth-discharging start point includes the distance between the earth-discharging start point and the rear gate of the dump truck DT, and the information about the earth-discharging end point includes the distance between the earth-discharging end point and the front panel of the dump truck DT.

[0234] The function block F1 is typically configured to calculate a target trajectory before each earth-releasing operation is started. That is, the target trajectory is typically updated before each earth-releasing operation is started. Specifically, the coordinates of the earth-releasing start point, which is the start point of the target trajectory, and the coordinates of the earth-releasing end point, which is the end point of the target trajectory, are updated before each earth-releasing operation is started.

[0235] The functional block F1 may be configured to display an image relating to the generated target trajectory on the display device D1.

[0236] The function block F1 may cause the display device D1 to display an image related to the target trajectory together with at least one of a rear monitoring image and a surrounding monitoring image. The rear monitoring image is an image that allows the operator to monitor the area behind the shovel 100, and is generated, for example, based on an image captured by the rear camera 80B. The surrounding monitoring image is an image that allows the operator to monitor the area around the shovel 100, and is, for example, an overhead image as a viewpoint conversion image that is generated by combining images captured by the rear camera 80B, the left camera 80L, and the right camera 80R. The overhead image is typically an image that shows the area around the shovel 100 as viewed from a virtual viewpoint directly above. The function block F1 may cause the display device D1 to display an image related to the target trajectory adjacent to at least one of the rear monitoring image and the surrounding monitoring image, for example.

[0237] Alternatively, the function block F1 may cause the display device D1 to display an image related to the target trajectory together with information related to the setting state of the shovel 100, which is information related to at least one of the engine rotation speed mode, the traveling mode, the type of attachment, the engine control state, etc. Alternatively, the function block F1 may cause the display device D1 to display an image related to the target trajectory together with information related to the operating state of the shovel, which is information related to at least one of the remaining amount of urea water, the remaining amount of fuel, the coolant temperature, the engine operating time, and the accumulated operating time.

[0238] The function block F2 is configured to calculate the current toe position. In the example of Fig. 10, the function block F2 calculates the coordinate point of the toe of the bucket 6 as the current toe position based on the boom angle β1 detected by the boom angle sensor S1, the arm angle β2 detected by the arm angle sensor S2, the bucket angle β3 detected by the bucket angle sensor S3, and the swing angle α1 detected by the swing angular velocity sensor S5. The function block F2 may use the output of the machine body tilt sensor S4 when calculating the current toe position.

[0239] The function block F3 is configured to calculate the next toe position. In the example of Fig. 10, in a manually operated manned excavator, the function block F3 calculates the toe position after a predetermined time as a target toe position based on the operation data output by the operating pressure sensor 29, the target trajectory generated by the function block F1, and the current toe position calculated by the function block F2. The processing flow in an automatically operated unmanned excavator will be described later.

[0240] The function block F3 may determine whether the deviation between the current toe position and the target trajectory is within an allowable range. In the example of FIG. 10, the function block F3 determines whether the distance between the current toe position and the target trajectory is equal to or less than a predetermined value. If the distance is equal to or less than the predetermined value, the function block F3 determines that the deviation is within the allowable range and calculates the target toe position. On the other hand, if the distance is greater than the predetermined value, the function block F3 determines that the deviation is not within the allowable range and slows down or stops the movement of the actuator regardless of the lever operation amount.

[0241] The function block F4 is configured to generate a command value related to the toe velocity. In the example of Fig. 10, the function block F4 calculates, as the command value related to the toe velocity, the toe velocity required to move the current toe position to the next toe position in a predetermined time based on the current toe position calculated by the function block F2 and the next toe position calculated by the function block F3.

[0242] The function block F5 is configured to limit the command value for the toe speed. In the example of FIG. 10 , when the function block F5 determines that the distance between the toe and a predetermined object, such as a dump truck DT, is less than a predetermined value based on the current toe position calculated by the function block F2 and an image captured by the imaging device 80 serving as a surroundings monitoring device, the function block F5 limits the command value for the toe speed to a predetermined upper limit. In this way, the controller 30 decelerates the toe speed when the toe approaches the predetermined object. The function block F5 may be configured to change the upper limit based on the weight of the material to be excavated taken into the bucket 6. Alternatively, the function block F5 may be configured to change the upper limit based on the turning radius of the excavation attachment AT. The turning radius of the excavation attachment AT may be calculated by the function block F2 or may be calculated by the function block F5 based on the output of the function block F2.

[0243] The function block F6 is configured to calculate a command value for operating the actuator. In the example of Fig. 10, the function block F6 calculates a command value β for the boom angle β1 based on the target toe position calculated by the function block F3 in order to move the current toe position to the target toe position. 1r , command value β for arm angle β 2r , command value β for bucket angle β 3r , and the command value α for the turning angle α 1r The function block F6 calculates the command value β as needed even when the boom 4 is not being operated. 1r This is to automatically operate the boom 4. The same applies to the arm 5, the bucket 6, and the rotation mechanism 2.

[0244] Next, the functional blocks for operating an autonomously operated unmanned excavator will be described. The above-mentioned functional blocks F1 to F6 and FA to FL are used in the same way when operating an autonomously operated unmanned excavator and when operating a manually operated manned excavator.

[0245] The communication device T1 is configured to control communication between the shovel 100 and an external device outside the shovel 100. In the example of FIG. 10 , the communication device T1 is configured to output a start command to the function block FM based on a signal received from the external device. The communication device T1 may also be configured to output operation data to the function block FM based on a signal received from the external device. However, the communication device T1 may also be an input device 43 mounted on the shovel 100.

[0246] The function block FM is configured to determine the start of work. In the example of FIG. 10 , when a start command is received from the communication device T1, the function block FM is configured to determine that an instruction to start work has been issued and to output a start command to the function block FN. When the start command is received from the communication device T1, the function block FM may be configured to output the start command to the function block FN when it is determined that no object is present around the excavator 100 based on the output of the imaging device 80 serving as a periphery monitoring device. When outputting the start command to the function block FN, the function block FM may output a command to an electromagnetic on-off valve arranged in a pilot line connecting the pilot pump 15 and the control valve unit 17 to open the pilot line.

[0247] The function block FN is configured to determine the content of the operation. In the example of Fig. 10, when the function block FN receives a start command from the function block FM, the function block FN is configured to determine, based on the current toe position calculated by the function block F2, whether an operation such as an excavation operation, a boom raising and swinging operation, an earth dumping operation, or a boom lowering and swinging operation is currently being performed, or whether none of the operations is being performed. Then, when the function block FN determines that the boom raising and swinging operation has ended based on the current toe position calculated by the function block F2, the function block FN is configured to output a start command to the function block FO.

[0248] The function block FO is configured to set the operating conditions of the excavator 100. In the example of Fig. 10, the function block FO is configured to set operating conditions such as the earth-discharging speed when the earth-discharging operation is performed by autonomous control and the bucket angle β3 at the start of earth-discharging when a start command is received from the function block FN. After setting the operating conditions, the function block FO is configured to output a start command to the function block FP.

[0249] The function block FP is configured to determine the start of a predetermined operation. In the example of FIG. 10 , when the function block FP receives a start command from the function block FO, it determines whether or not the earth-releasing operation can be started based on the current toe position of the bucket 6 calculated by the function block F2. Specifically, the function block FP determines whether or not the boom-raising and swinging operation has ended and whether or not the toe of the bucket 6 has reached the earth-releasing start point, based on the current toe position. Then, when the function block FP determines that the boom-raising and swinging operation has ended and that the toe of the bucket 6 has reached the earth-releasing start point, it determines that the earth-releasing operation can be started. Then, when it determines that the earth-releasing operation can be started, the function block FP causes operation data automatically generated in the autonomous unmanned excavator to be input to the function block F3.

[0250] With this configuration, the controller 30 can perform excavation operations by autonomous control in an automatically operated unmanned excavator in the same way as in a manually operated manned excavator.

[0251] Furthermore, the above-described embodiment discloses a hydraulic operation system equipped with a hydraulic pilot circuit. Specifically, in the hydraulic pilot circuit related to the operation of the arm 5, hydraulic oil supplied from the pilot pump 15 to the remote control valve of the left operating lever 26L is transmitted to the pilot port of the control valve 176, which serves as an arm control valve, at a flow rate corresponding to the degree of opening of the remote control valve, which is opened or closed by operating the left operating lever forward or backward.

[0252] However, instead of a hydraulic operation system with such a hydraulic pilot circuit, an electric operation system including an electric control lever with an electric pilot circuit may be employed. In this case, the lever operation amount of the electric control lever is input as an electric signal to the controller 30. A solenoid valve is disposed between the pilot pump 15 and the pilot port of each control valve. The solenoid valve is configured to operate in response to an electric signal from the controller 30. With this configuration, when manual operation is performed using the electric control lever, the controller 30 controls the solenoid valve with an electric signal corresponding to the lever operation amount to increase or decrease the pilot pressure, thereby moving each control valve within the control valve unit 17. Each control valve may be configured as a solenoid spool valve. In this case, the solenoid spool valve operates in response to an electric signal from the controller 30 corresponding to the lever operation amount of the electric control lever.

[0253] When an electric operation system including an electric operation lever is employed, the controller 30 can more easily execute the autonomous control function than when a hydraulic operation system including a hydraulic operation lever is employed. FIG. 11 shows an example of the configuration of an electric operation system. Specifically, the electric operation system of FIG. 11 is an example of a boom operation system, and is mainly composed of a pilot pressure operated control valve unit 17, a right operation lever 26R as an electric operation lever, a controller 30, a solenoid valve 65 for boom-raising operation, and a solenoid valve 66 for boom-lowering operation. The electric operation system of FIG. 11 can also be applied to arm operation systems, bucket operation systems, etc.

[0254] The pilot pressure operated control valve unit 17 includes a control valve 175 (see Figure 2) for the boom cylinder 7, a control valve 176 (see Figure 2) for the arm cylinder 8, and a control valve 174 (see Figure 2) for the bucket cylinder 9. The solenoid valve 65 is configured to be able to adjust the flow path area of the pipe connecting the pilot pump 15 and the up-side pilot port of the control valve 175. The solenoid valve 66 is configured to be able to adjust the flow path area of the pipe connecting the pilot pump 15 and the down-side pilot port of the control valve 175.

[0255] When manual operation is performed, the controller 30 generates a boom-raising operation signal (electrical signal) or a boom-lowering operation signal (electrical signal) in response to an operation signal (electrical signal) output by an operation signal generating section of the right operation lever 26R. The operation signal output by the operation signal generating section of the right operation lever 26R is an electric signal that changes in response to the amount and direction of operation of the right operation lever 26R.

[0256] Specifically, when the right operating lever 26R is operated in the boom-up direction, the controller 30 outputs a boom-raising operation signal (electrical signal) corresponding to the lever operation amount to the solenoid valve 65. The solenoid valve 65 adjusts the flow path area in accordance with the boom-raising operation signal (electrical signal) and controls the pilot pressure as a boom-raising operation signal (pressure signal) acting on a raising-side pilot port of the control valve 175. Similarly, when the right operating lever 26R is operated in the boom-lowering direction, the controller 30 outputs a boom-lowering operation signal (electrical signal) corresponding to the lever operation amount to the solenoid valve 66. The solenoid valve 66 adjusts the flow path area in accordance with the boom-lowering operation signal (electrical signal) and controls the pilot pressure as a boom-lowering operation signal (pressure signal) acting on a lowering-side pilot port of the control valve 175.

[0257] When performing autonomous control, the controller 30 generates a boom-raising operation signal (electrical signal) or a boom-lowering operation signal (electrical signal) in response to an autonomous control signal (electrical signal) output by an autonomous control signal generator, instead of responding to an operation signal (electrical signal) output by an operation signal generator of the right operation lever 26R. The autonomous control signal may be an electric signal generated by the controller 30, or may be an electric signal generated by an external control device other than the controller 30.

[0258] Information acquired by the shovel 100 may be shared with an administrator, operators of other shovels, etc. through an shovel management system SYS as shown in FIG. 12. FIG. 12 is a schematic diagram showing an example configuration of an shovel management system SYS. The management system SYS is a system that manages one or more shovels 100. In this embodiment, the management system SYS is mainly composed of an shovel 100, a support device 200, and a management device 300. The shovel 100, the support device 200, and the management device 300 that make up the management system SYS may each be one unit or multiple units. In the example of FIG. 12, the management system SYS includes one shovel 100, one support device 200, and one management device 300.

[0259] The support device 200 is typically a mobile terminal device, such as a notebook PC, tablet PC, or smartphone carried by a worker or the like at a construction site. The support device 200 may also be a computer carried by the operator of the shovel 100. The support device 200 may also be a fixed terminal device.

[0260] The management device 300 is typically a fixed terminal device, such as a server computer installed in a management center outside the construction site, etc. The management device 300 may also be a portable computer (for example, a notebook PC, a tablet PC, or a mobile terminal device such as a smartphone).

[0261] At least one of the support device 200 and the management device 300 may be equipped with a monitor and an operation device for remote operation. In this case, the operator may operate the shovel 100 while using the operation device for remote operation. The operation device for remote operation is connected to the controller 30 via a communication network such as a wireless communication network, for example. The following describes the exchange of information between the shovel 100 and the management device 300, but the following description also applies to the exchange of information between the shovel 100 and the support device 200.

[0262] In the management system SYS for the shovel 100 described above, the controller 30 of the shovel 100 may transmit to the management device 300 information relating to at least one of the time and location when autonomous control was started or stopped, the target trajectory used during autonomous control, and the trajectory actually followed by a predetermined portion during autonomous control. In this case, the controller 30 may transmit to the management device 300, for example, images captured by the imaging device 80 serving as a surroundings monitoring device. The images may be multiple images captured during a predetermined period including the period during which autonomous control was executed. Furthermore, the controller 30 may transmit to the management device 300 information relating to at least one of data relating to the work content of the shovel 100, data relating to the attitude of the shovel 100, and data relating to the attitude of the excavating attachment AT during the predetermined period including the period during which autonomous control was executed. This is to enable the manager using the management device 300 to obtain information about the work site. The data relating to the work content of the shovel 100 is, for example, at least one of the following: the number of loading operations, which is the number of times the earth-discharging operation has been performed; information about the excavated material, such as earth and sand, loaded onto the bed of the dump truck DT; the type of dump truck DT related to the loading operation; information about the position of the shovel 100 when the loading operation was performed; information about the work environment; and information about the operation of the shovel 100 when the loading operation was performed. The information about the excavated material is, for example, at least one of the weight and type of the material excavated in each excavation operation, the weight and type of the material loaded onto the dump truck DT, and the weight and type of the material loaded in one day's loading operation. The information about the work environment is, for example, information about the slope of the ground around the shovel 100 or information about the weather around the work site. The information about the operation of the shovel 100 is, for example, at least one of the output of the operating pressure sensor 29 and the output of the cylinder pressure sensor S10.

[0263] Furthermore, in the above-described embodiment, the autonomous control unit 30B is configured to autonomously assist the operator in manually operating the excavator 100. For example, when the operator is manually performing an arm closing operation, the autonomous control unit 30B operates at least one of the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the swing hydraulic motor 2A so that the trajectory of the toe of the bucket 6 matches the target trajectory. However, the present invention is not limited to this configuration. For example, when the operator is not operating the control device 26, the autonomous control unit 30B may operate at least one of the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the swing hydraulic motor 2A so that the trajectory of the toe of the bucket 6 matches the target trajectory. In other words, the autonomous control unit 30B may autonomously move the excavation attachment AT without being operated by the operator. In this case, the autonomous control unit 30B may be configured to appropriately move the excavation attachment AT using artificial intelligence technology.

[0264] The controller 30 may also be configured to calculate the weight of the material to be excavated, such as soil and sand, during the boom-raising and swinging operation. The controller 30 calculates the weight of the material to be excavated, for example, based on the balance of two torques acting on the boom 4 around the boom foot pin. The two torques are an ascending torque (holding torque) acting in a direction to raise the boom 4 and a descending torque (gravity torque) acting in a direction to lower the boom 4. The holding torque is calculated based on the thrust force of the extending boom cylinder 7, and increases as the thrust force increases. The thrust force of the extending boom cylinder 7 is calculated based on the outputs of the boom rod pressure sensor and the boom bottom pressure sensor. The gravity torque includes torque due to the weight of the excavation attachment AT and torque due to the weight of the material to be excavated. The torque due to the weight of the excavation attachment AT is calculated based on the distance between the center of gravity of the excavation attachment AT and the boom foot pin, which is the center of rotation of the boom 4, and the weight of the excavation attachment AT. The torque due to the weight of the object to be excavated is calculated based on the distance between the center of gravity of the object to be excavated and the boom foot pin, and the weight of the object to be excavated. The center of gravity of the digging attachment AT is derived from the attitude of the digging attachment AT. The controller 30 may derive the center of gravity of the digging attachment AT by referring to a reference table stored in a non-volatile memory device, for example, that defines the correspondence between the attitude of the digging attachment AT and the center of gravity position. The attitude of the digging attachment AT is derived based on the output of the attitude detection device. The weight of the digging attachment AT is known and may be stored in advance in a non-volatile memory device. The controller 30 may derive the torque due to the weight of the digging attachment AT by referring to a reference table that defines the correspondence between the attitude of the digging attachment AT and the torque due to the weight of the digging attachment AT.

[0265] The controller 30 may then subtract the magnitude of the gravity torque due to the weight of the excavation attachment AT from the magnitude of the holding torque to calculate the gravity torque due to the weight of the object being excavated. This is because the magnitude of the holding torque is balanced with the magnitude of the gravity torque. Also, the gravity torque is the sum of the torque due to the weight of the excavation attachment AT and the torque due to the weight of the object being excavated.

[0266] Then, the controller 30 can calculate the gravity of the object to be excavated based on the magnitude of the gravitational torque due to the weight of the object and the position of the center of gravity of the object to be excavated. The position of the center of gravity of the object to be excavated is calculated, for example, from the shape of the object to be excavated derived based on the output of the object detection device 70. The position of the center of gravity of the object to be excavated may be preset as a predetermined point within the bucket 6.

[0267] In this embodiment, the controller 30 is configured to calculate the weight of the material to be excavated each time an excavation operation is completed and a boom raising and swinging operation is started. Then, while loading is being performed on the same dump truck DT, the controller 30 adds up the weight of the material to be excavated calculated each time a boom raising and swinging operation is started to calculate the total weight of the material to be excavated loaded on the bed of the dump truck DT. When the dump truck DT to be loaded is replaced, the total weight of the material to be excavated is reset to zero.

[0268] If there is a risk that the sum of the weight of the material to be excavated currently taken into the bucket 6 and the total weight of the material to be excavated already loaded on the bed of the dump truck DT will exceed the maximum load capacity of the dump truck DT, the controller 30 may interrupt the discharging operation midway without discharging the material to be excavated in the bucket 6. In this case, the controller 30 may calculate the weight of the excess material to be excavated, and then calculate the volume of the excess material to be excavated, and interrupt the discharging operation midway so that material to be excavated of that volume remains in the bucket 6. Then, the controller 30 may execute a leveling operation with the back surface of the bucket 6, leaving the material to be excavated in the bucket 6.

[0269] This application claims priority based on Japanese Patent Application No. 2019-169178, filed on September 18, 2019, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0270] 1···Undercarriage 1C···Crawler 1CL··Left crawler 1CR···Right crawler 2···Slewing mechanism 2A···Slewing hydraulic motor 2M···Travel hydraulic motor 2ML···Left travel hydraulic motor 2MR···Right travel hydraulic motor 3···Upper rotating body 4···Boom 5···Arm 6···Bucket 7···Boom cylinder 8···Arm cylinder 9···Bucket cylinder 10···Cabin 11··Engine 13···Regulator 14···Main pump 15···Pilot pump 17···Control valve unit 18···Throttle 19···Control pressure sensor 26···Operating device 26D···Travel lever 26DL···Left travel lever 26DR···Right travel lever 26L···Left operating lever 26R Right operating lever 28 Discharge pressure sensor 29, 29DL, 29DR, 29LA, 29LB, 29RA, 29RB Operating pressure sensor 30 Controller 30A Trajectory generating unit 30B Autonomous control unit 31, 31AL to 31DL, 31AR to 31DR Proportional valve 32, 32AL to 32DL, 32AR to 32DR Shuttle valve 33, 33AL to 33DL, 33AR to 33DR Proportional valve 40 Center bypass pipe 42 Parallel pipe 43 Input device 65, 66 Solenoid valves 70 Object detection device 70F Front sensor 70B Rear sensor 70L Left sensor 70R Right sensor 80 Imaging device 80B···Rear camera 80F···Front camera 80L···Left camera 80R···Right camera 100···Shovel 171~176···Control valve 200···Support device 300···Management device AT···Digging attachment BD···Loading platform D1···Display device D2···Sound output device DT···Dump truck F1~F6, FA~FP···Function block FR···Front panel LD, LD1~LD3···Load NS···Switch RG···Rear gate S1···Boom angle sensor S2···Arm angle sensor S3···Bucket angle sensor S4···Machine tilt sensor S5···Slewing angular velocity sensor S6···Slewing spool displacement sensor S7···Boom spool displacement sensor S8···Arm spool displacement sensorS9: Bucket spool displacement sensor S10: Cylinder pressure sensor SP1 to SP6: Space SYS: Management system T1: Communication device TL, TL1 to TL4: Target trajectory

Claims

1. a lower running body; an upper rotating body rotatably mounted on the lower traveling body; a control device provided on the upper rotating body, The control device is configured to recognize the position of the dump truck and generate a target trajectory for the earth-releasing operation, and when the height of the newly formed load exceeds a predetermined height, the control device operates the bucket so as to level the upper surface of the load with the back surface of the bucket. Shovel.

2. A control device for a shovel having a lower traveling body and an upper rotating body rotatably mounted on the lower traveling body, The system is configured to recognize the position of the dump truck and generate a target trajectory for the earth-releasing operation, and when the height of the newly formed load exceeds a predetermined height, the system operates the bucket so as to level the upper surface of the load with the back surface of the bucket. Excavator control device.

3. a shovel including a lower traveling body and an upper rotating body rotatably mounted on the lower traveling body; an operating device for remote operation connected to the shovel via a communication network; a control device for the shovel, The control device is configured to recognize the position of the dump truck and generate a target trajectory for the earth-releasing operation, and when the height of the newly formed load exceeds a predetermined height, the control device operates the bucket so as to level the upper surface of the load with the back surface of the bucket. Excavator management system.

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