Excavator, excavator control device, and excavator management system

Abstract

To provide an excavator capable of executing an autonomous soil release operation.SOLUTION: An excavator 100 includes:an undercarriage 1; an upper rotating body 3 rotatably mounted on the undercarriage 1; and a controller 30 placed on the upper rotating body 3. The controller 30 is configured to recognize the position of a dump truck DT and to generate a target trajectory TL for soil release 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 predetermined height along the bottom surface of the loading platform BD of the dump truck DT.SELECTED DRAWING: Figure 7A

Description

Technical Field

[0001] The present disclosure relates to an excavator.

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the above-described excavation control system assumes that the dumping operation is performed manually. Therefore, the above-described excavation control system cannot improve the efficiency of the dumping operation.

[0005] Therefore, it is desirable to provide an excavator capable of autonomously executing the dumping operation.

Means for Solving the Problems

[0006] An excavator according to an embodiment of the present invention includes a lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, and a control device provided on the upper slewing body. The control device is configured to recognize the position of a dump truck and generate a target trajectory related to the dumping operation.

Effects of the Invention

[0007] By the above means, an excavator capable of autonomously executing the dumping operation is provided.

Brief Description of the Drawings

[0008]

Figure 1A

Figure 1B

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4

Figure 5

Figure 6

Figure 7A

Figure 7B

Figure 7C

Figure 7D

Figure 8A

Figure 8B

Figure 8C

Figure 8D

Figure 8E

Figure 9A

Figure 9B

Figure 9C

Figure 9D

Figure 9E

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

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

[0010] In the present embodiment, the lower traveling body 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 body 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] The upper swing body 3 is mounted on the lower traveling body 1 so as to be swingable via a swing mechanism 2. The swing mechanism 2 is driven by a swing hydraulic motor 2A mounted on the upper swing body 3. However, the swing hydraulic motor 2A may be a swing electric generator as an electric actuator.

[0012] A boom 4 is attached to the upper swing body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 as an end attachment is attached to the tip of the arm 5. The boom 4, the arm 5, and the bucket 6 constitute 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 by the upper swing body 3 so as to be pivotable vertically. 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 rising angle from the state where the boom 4 is lowered most. Therefore, the boom angle β1 becomes maximum when the boom 4 is raised most.

[0014] The arm 5 is supported by the boom 4 so as to be pivotable. 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 from the state where the arm 5 is closed most. Therefore, the arm angle β2 becomes maximum when the arm 5 is opened most.

[0015] The bucket 6 is supported by the arm 5 so as to be pivotable. 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 from the state where the bucket 6 is closed most. Therefore, the bucket angle β3 becomes maximum when the bucket 6 is opened most.

[0016] In the embodiments shown in FIGS. 1A and 1B, each of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 is composed of a combination of an acceleration sensor and a gyro sensor. However, each of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 may be composed of only an acceleration sensor. Further, 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 swing body 3 is provided with a cabin 10 as an operator's cab, and is equipped with one or more power sources. In the present embodiment, the upper swing body 3 is equipped with an engine 11 as a power source. Further, an object detection device 70, an imaging device 80, a machine body inclination sensor S4, a swing angular velocity sensor S5, etc. are attached to the upper swing body 3. Inside the cabin 10, an operation device 26, a controller 30, a display device D1, a sound output device D2, etc. are provided. In this document, for convenience, the side of the upper swing body 3 where the excavation attachment AT is attached is defined as the front side, and the side where the counterweight is attached is defined as the rear side.

[0018] The object detection device 70 is an example of a space recognition device, and is configured to detect an object existing around the excavator 100. The object is, for example, a person, an animal, a vehicle, a construction machine, a building, a wall, a fence, or a hole. 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 the present embodiment, the object detection device 70 includes a front sensor 70F attached to the front end of the upper surface of the cabin 10, a rear sensor 70B attached to the rear end of the upper surface of the upper swing body 3, a left sensor 70L attached to the left end of the upper surface of the upper swing body 3, and a right sensor 70R attached to the right end of the upper surface of the upper swing body 3. Each sensor is composed of a LIDAR.

[0019] The object detection device 70 may be configured to detect a predetermined object within a predetermined area set around the excavator 100. That is, the object detection device 70 may be configured to be able to identify the type of the object. For example, the object detection device 70 may be configured to be able to distinguish between a person and an object other than a person. The object detection device 70 may be configured to calculate the distance from the object detection device 70 or the excavator 100 to the recognized object.

[0020] And, when it is determined by the space recognition device (object detection device 70) that a person exists within a range (predetermined range) of a predetermined distance from the excavator 100 before the actuator operates, the controller 30 may disable the actuator or set it to a very slow state even if an operation command has already been output. The actuator is, for example, a hydraulic actuator or an electric actuator or the like. The hydraulic actuator is, for example, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the like.

[0021] Specifically, when it is determined that a person is present within a 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 operation lever, the controller 30 can disable the actuator by invalidating the signal from the controller 30 to the operation control valve. When setting the actuator to a very low speed state, the controller 30 may, for example, reduce the signal from the controller 30 to the operation control valve. Thus, when it is determined that a person is present within a predetermined range, even if the controller 30 has already generated an operation command, the controller 30 does not drive the actuator or drives it at a very low speed. Further, when it is determined that a person is present within a predetermined range while the operator is operating the operation lever, the controller 30 may stop or decelerate the operation of the actuator regardless of the operator's operation. Specifically, when it is determined that a person is present within a 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 using the operation control valve, the controller 30 can disable the actuator or set it to a very low speed state by invalidating the signal to the operation control valve or 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. Also, when 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. Thus, the controller 30 can appropriately control the movement of the actuator based on the type of the detected object.

[0022] The imaging device 80 is configured to image 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 slewing body 3, a front camera 80F attached to the front end of the upper surface of the cab 10, a left camera 80L attached to the left end of the upper surface of the upper slewing body 3, and a right camera 80R attached to the right end of the upper surface of the upper slewing body 3.

[0023] The rear camera 80B is arranged adjacent to the rear sensor 70B, the front camera 80F is arranged adjacent to the front sensor 70F, the left camera 80L is arranged adjacent to the left sensor 70L, and the right camera 80R is arranged 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 conversion image such as an aerial view image on the display device D1. The aerial view image is generated, for example, by synthesizing the images output by the rear camera 80B, the left camera 80L, and the right camera 80R respectively.

[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 body tilt sensor S4 is configured to detect the tilt of the upper slewing body 3 with respect to a predetermined plane. In this embodiment, the body tilt sensor S4 is an acceleration sensor that detects the tilt angle around the front-rear axis and the tilt angle around the left-right axis of the upper slewing body 3 with respect to the virtual horizontal plane. The front-rear axis and the left-right axis of the upper slewing body 3 pass through, for example, a point on the slewing axis of the excavator 100 that is the excavator center point and are perpendicular to each other.

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

[0028] Hereinafter, each of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the body inclination sensor S4, and the turning angular velocity sensor S5 is also referred to as an attitude detection device.

[0029] The display device D1 is a device for displaying information. The sound output device D2 is a device for outputting sound. The operation device 26 is a device used by an operator for operating the actuator.

[0030] The controller 30 is a control device for controlling the excavator 100. In the present embodiment, the controller 30 is composed of a computer including a CPU, a volatile memory device, a non-volatile memory device, and the like. Then, the controller 30 reads out a program corresponding to each function from the non-volatile memory device and loads it into the volatile memory device, and causes the CPU to execute the corresponding process. Each function includes, for example, a machine guidance function for guiding (guiding) the manual operation of the excavator 100 by the operator, and a machine control function for automatically assisting the manual operation of the excavator 100 by the operator.

[0031] Next, with reference to FIG. 2, a configuration example of the hydraulic system mounted on the excavator 100 will be described. FIG. 2 is a diagram showing a configuration example of the hydraulic system mounted on the excavator 100. FIG. 2 shows the mechanical power transmission line, the hydraulic oil line, the pilot line, and the electric control line with double lines, solid lines, broken 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 operation device 26, a discharge pressure sensor 28, an operation pressure sensor 29, and a controller 30, and the like.

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

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

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

[0036] The regulator 13 is configured to control the discharge amount (push-back volume) of the main pump 14. In the present embodiment, the regulator 13 controls the discharge amount (push-back volume) of the main pump 14 by adjusting the swash plate tilt angle of the main pump 14 according to a control command from the controller 30.

[0037] The pilot pump 15 is configured to supply hydraulic oil to hydraulic control equipment including the operating device 26 via a pilot line. In the present embodiment, the pilot pump 15 is a fixed displacement hydraulic pump. However, the pilot pump 15 may be omitted. In this case, the function that the pilot pump 15 has assumed may be realized by the main pump 14. That is, the main pump 14 may be provided with a function of supplying hydraulic oil to the operating device 26 etc. 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 the present 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 the hydraulic oil discharged by the main pump 14 to one or a plurality of hydraulic actuators through the control valves 171 to 176. The control valves 171 to 176 control the flow rate of the hydraulic oil flowing from the main pump 14 to the hydraulic actuator and the flow rate of the hydraulic oil flowing from the hydraulic actuator to the hydraulic oil tank. The hydraulic actuators include a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left travel hydraulic motor 2ML, a right travel hydraulic motor 2MR, and a swing hydraulic motor 2A.

[0039] The operating device 26 is a device used by the operator for operating the actuator. The actuator includes at least one of a hydraulic actuator and an electric actuator. In the present embodiment, the operating device 26 supplies, via a pilot line, the hydraulic oil discharged by the pilot pump 15 to the pilot ports of the corresponding control valves in the control valve unit 17. The pressure of the hydraulic oil (pilot pressure) supplied to each of the pilot ports is a pressure corresponding to the operation direction and operation amount of a lever or pedal (not shown) of the operating device 26 corresponding to each of the hydraulic actuators. However, the operating device 26 may be an electric operating device instead of the hydraulic operating device as 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 the present 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 content of the operation of the operating device 26 by the operator. In the present embodiment, the operation pressure sensor 29 detects the operation direction and operation amount of the operating device 26 corresponding to each actuator in the form of pressure (operation pressure), and outputs the detected value to the controller 30 as operation data. The content of the operation of the operating device 26 may be detected using other sensors 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 the hydraulic oil to the hydraulic oil tank through the left center bypass pipeline 40L or the left parallel pipeline 42L. The right main pump 14R is configured to circulate the hydraulic oil to the hydraulic oil tank through the right center bypass pipeline 40R or the right parallel pipeline 42R.

[0043] The left center bypass pipeline 40L is a hydraulic oil line passing through the control valves 171, 173, 175L, and 176L arranged in the control valve unit 17. The right center bypass pipeline 40R is a hydraulic oil line passing through the 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 from the left main pump 14L to the left traveling hydraulic motor 2ML and to discharge the hydraulic oil discharged from 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 from the right main pump 14R to the right traveling hydraulic motor 2MR and to discharge the hydraulic oil discharged from 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 from the left main pump 14L to the swing hydraulic motor 2A and to discharge the hydraulic oil discharged from 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 from 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 from 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 from 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 from 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 from 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 pipeline 42L is a hydraulic oil line parallel to the left center bypass pipeline 40L. When the flow of hydraulic oil through the left center bypass pipeline 40L is restricted or blocked by any one of the control valves 171, 173, or 175L, the left parallel pipeline 42L can supply hydraulic oil to the downstream control valve. The right parallel pipeline 42R is a hydraulic oil line parallel to the right center bypass pipeline 40R. When the flow of hydraulic oil through the right center bypass pipeline 40R is restricted or blocked by any one of the control valves 172, 174, or 175R, the right parallel pipeline 42R can supply hydraulic oil to the downstream control valve.

[0052] The regulator 13 includes a left regulator 13L and a right regulator 13R. The left regulator 13L controls the discharge volume of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L according to the discharge pressure of the left main pump 14L. Specifically, for example, the left regulator 13L adjusts the swash plate tilt angle of the left main pump 14L in response to an increase in the discharge pressure of the left main pump 14L to reduce the discharge volume. The same applies to the right regulator 13R. This is to ensure that the absorption power (e.g., absorption horsepower) of the main pump 14, which is represented by the product of the discharge pressure and the discharge volume, does not exceed 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 traveling lever 26D. The traveling lever 26D includes a left traveling lever 26DL and a right traveling lever 26DR.

[0054] The left operating lever 26L is used for the turning operation and the operation of the arm 5. When the left operating lever 26L is operated in the front-rear direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and applies a control pressure corresponding to the lever operation amount to the pilot port of the control valve 176. When it is operated in the left-right direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and applies a control pressure corresponding to the lever operation amount to the pilot port of the control valve 173.

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

[0056] The right operation lever 26R is used for the operation of the boom 4 and the operation of the bucket 6. When the right operation lever 26R is operated in the front-rear direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and applies a control pressure corresponding to the lever operation amount to the pilot port of the control valve 175. Also, when it is operated in the left-right direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and applies a control pressure corresponding to the lever operation amount to the pilot port of the control valve 174.

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

[0058] The traveling lever 26D is used for the operation of the crawler 1C. Specifically, the left traveling lever 26DL is used for the operation of the left crawler 1CL. The left traveling lever 26DL may be configured to be interlocked with the left traveling pedal. When the left traveling lever 26DL is operated in the front-rear direction, it uses the hydraulic oil discharged from the pilot pump 15 and applies a control pressure corresponding to the lever operation amount to the pilot port of the control valve 171. The right traveling lever 26DR is used for the operation of the right crawler 1CR. The right traveling lever 26DR may be configured to be interlocked with the right traveling pedal. When the right traveling lever 26DR is operated in the front-rear direction, it uses the hydraulic oil discharged from the pilot pump 15 and applies 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, in the form of pressure, the content of the front-rear direction operation on the left operation lever 26L by the operator and outputs the detected value to the controller 30. The content of the operation is, for example, the lever operation direction and the lever operation amount (lever operation angle), etc.

[0061] Similarly, the operation pressure sensor 29LB detects, in the form of pressure, the content of the left - right direction operation on the left operation lever 26L by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29RA detects, in the form of pressure, the content of the front - rear direction operation on the right operation lever 26R by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29RB detects, in the form of pressure, the content of the left - right direction operation on the right operation lever 26R by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29DL detects, in the form of pressure, the content of the front - rear direction operation on the left travel lever 26DL by the operator, and outputs the detected value to the controller 30. The operation pressure sensor 29DR detects, in the form of pressure, the content of the front - rear direction operation on the right travel lever 26DR by the operator, and outputs the detected value to the controller 30.

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

[0063] In the left center bypass pipeline 40L, a left throttle valve 18L is arranged between the most downstream control valve 176L and the hydraulic oil tank. Therefore, the flow of the hydraulic oil discharged by the left main pump 14L is restricted by the left throttle valve 18L. And the left throttle valve 18L generates a control pressure for controlling the left regulator 13L. The left control pressure sensor 19L is a sensor for detecting this control pressure and outputs the detected value to the controller 30. The controller 30 controls the discharge amount of the left main pump 14L by adjusting the swash plate tilt angle of the left main pump 14L according to this control pressure. The controller 30 decreases the discharge amount of the left main pump 14L as this control pressure increases, and increases the discharge amount of the left main pump 14L as this control pressure decreases. The discharge amount of the right main pump 14R is controlled in the same way.

[0064] Specifically, as shown in FIG. 2, when the hydraulic actuators in the excavator 100 are all in the standby state where none of them are operated, the hydraulic oil discharged by the left main pump 14L reaches the left throttle valve 18L through the left center bypass pipeline 40L. And the flow of the hydraulic oil discharged by the left main pump 14L increases the control pressure generated upstream of the left throttle valve 18L. As a result, the controller 30 decreases the discharge amount of the left main pump 14L to the allowable minimum discharge amount and suppresses the pressure loss (pumping loss) when the hydraulic oil discharged by the left main pump 14L passes through the left center bypass pipeline 40L. On the other hand, when any of the hydraulic actuators is operated, the hydraulic oil discharged by the left main pump 14L flows into the hydraulic actuator to be operated through the control valve corresponding to the hydraulic actuator to be operated. And the flow of the hydraulic oil discharged by the left main pump 14L decreases or disappears the amount reaching the left throttle valve 18L and decreases the control pressure generated upstream of the left throttle valve 18L. As a result, the controller 30 increases the discharge amount of the left main pump 14L, allows sufficient hydraulic oil to flow into the hydraulic actuator to be operated, and ensures the driving of the hydraulic actuator to be operated. Note that the controller 30 controls the discharge amount of the right main pump 14R in the same way.

[0065] With the above configuration, the hydraulic system in FIG. 2 can suppress unnecessary energy consumption related to the main pump 14 in the standby state. The unnecessary energy consumption includes the pumping loss generated by the hydraulic oil discharged from the main pump 14 in the center bypass pipeline 40. Further, when operating the hydraulic actuator, the hydraulic system in FIG. 2 can reliably supply sufficient hydraulic oil from the main pump 14 to the hydraulic actuator to be operated.

[0066] Next, referring to FIGS. 3A to 3D, the configuration for the controller 30 to automatically operate the actuator by the machine control function will be described. FIGS. 3A to 3D are partial views of the hydraulic system. Specifically, FIG. 3A is a partial view of the hydraulic system related to the operation of the arm cylinder 8, and FIG. 3B is a partial view of the hydraulic system related to the operation of the swing hydraulic motor 2A. Further, FIG. 3C is a partial view of the hydraulic system related to the operation of the boom cylinder 7, and FIG. 3D is a partial view of the hydraulic system related to the operation of the bucket cylinder 9.

[0067] As shown in FIGS. 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 arranged in the pipeline connecting the pilot pump 15 and the shuttle valve 32, and is configured to be able to change the flow area of the pipeline. In the present embodiment, the proportional valve 31 operates according to the control command output by the controller 30. Therefore, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17 via the proportional valve 31 and the shuttle valve 32, regardless of the operation of the operation 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 one of the pilot pressure generated by the operating device 26 and the pilot pressure generated by the proportional valve 31 to the pilot port of the corresponding control valve.

[0070] Similar to the proportional valve 31, the proportional valve 33 functions as a control valve for machine control. The proportional valve 33 is arranged in the pipeline connecting the operating device 26 and the shuttle valve 32 and is configured to be able to change the flow passage area of the pipeline. In this embodiment, the proportional valve 33 operates according to the control command output by the controller 30. Therefore, the controller 30 can depressurize 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 the specific operating device 26 even when no operation on the specific operating device 26 is being performed. Also, the controller 30 can forcibly stop the operation of the hydraulic actuator corresponding to the specific operating device 26 even when an operation on the specific operating device 26 is being performed.

[0072] For example, as shown in FIG. 3A, the left operation lever 26L is used to operate the arm 5. Specifically, the left operation lever 26L utilizes the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the operation in the front-rear direction to the pilot port of the control valve 176. More specifically, when the left operation lever 26L is operated in the arm closing direction (rear direction), a pilot pressure corresponding to the operation amount is applied to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R. Also, when the left operation lever 26L is operated in the arm opening direction (front direction), a pilot pressure corresponding to the operation amount is applied to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R.

[0073] A switch NS is provided on the left operation lever 26L. In the present embodiment, the switch NS is a push button switch. The operator can operate the left operation lever 26L by hand while pressing the switch NS with a finger. The switch NS may be provided on the right operation lever 26R or at other positions within the cabin 10.

[0074] The operation pressure sensor 29LA detects the content of the front-rear direction operation of the left operation lever 26L by the operator in the form of pressure and outputs the detected value to the controller 30.

[0075] The proportional valve 31AL operates according to the current command output by the controller 30. Then, the proportional valve 31AL adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the proportional valve 31AL and the shuttle valve 32AL. The proportional valve 31AR operates according to the current command output by the controller 30. Then, the proportional valve 31AR adjusts the pilot pressure by the 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 an arbitrary valve position. Also, the proportional valve 31AR can adjust the pilot pressure so that the control valve 176R can be stopped at an arbitrary 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. Also, 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 according to a control command (current command) output by the controller 30. Then, the pilot pressure generated by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R via the left operation lever 26L, the proportional valve 33AL, and the shuttle valve 32AL is reduced. The proportional valve 33AR operates according to a control command (current command) output by the controller 30. Then, the pilot pressure generated by the 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 operation lever 26L, the proportional valve 33AR, and the shuttle valve 32AR is reduced. The proportional valves 33AL and 33AR can adjust the pilot pressure so that the control valves 176L and 176R can be stopped at arbitrary valve positions, respectively.

[0078] With this configuration, even when the operator performs an arm closing operation, the controller 30 can, if 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), and forcibly stop the closing operation of the arm 5. The same applies when forcibly stopping the opening operation of the arm 5 when the operator performs an arm opening operation.

[0079] Alternatively, even when the operator performs an arm closing operation, the controller 30 can, if necessary, control the proportional valve 31AR 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), which are on the opposite side of the closing-side pilot ports of the control valve 176, and forcibly return 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 when forcibly stopping the opening operation of the arm 5 when the operator performs an arm opening operation.

[0080] Also, although the description with reference to FIGS. 3B to 3D below is omitted, when the slewing operation of the upper slewing body 3 is forcibly stopped when the operator performs a slewing operation, when the boom raising operation or the boom lowering operation by the operator is being performed and the operation of the boom 4 is forcibly stopped, and when the bucket closing operation or the bucket opening operation by the operator is being performed and the operation of the bucket 6 is forcibly stopped, the same applies. Also, the same applies when the traveling operation of the lower traveling body 1 is forcibly stopped when the operator performs a traveling operation.

[0081] Also, as shown in FIG. 3B, the left operation lever 26L is also used to operate the slewing mechanism 2. Specifically, the left operation lever 26L uses the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the left-right direction operation to the pilot port of the control valve 173. More specifically, when the left operation lever 26L is operated in the left slewing direction (left direction), it applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 173. Also, when the left operation lever 26L is operated in the right slewing direction (right direction), it 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 content of the left-right direction operation on the left operation lever 26L by the operator in the form of pressure and outputs the detected value to the controller 30.

[0083] The proportional valve 31BL operates according to the current command output by the controller 30. Then, the proportional valve 31BL adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31BL and the shuttle valve 32BL. The proportional valve 31BR operates according to the current command output by the controller 30. Then, the proportional valve 31BR adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31BR and the shuttle valve 32BR. The proportional valves 31BL and 31BR can adjust the pilot pressure so that the control valve 173 can be stopped at an arbitrary 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 turn operation by the operator. That is, the controller 30 can automatically turn the slewing mechanism 2 to the left. Also, 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 turn operation by the operator. That is, the controller 30 can automatically turn the slewing mechanism 2 to the right.

[0085] Also, as shown in FIG. 3C, the right operation lever 26R is used to operate the boom 4. Specifically, the right operation lever 26R utilizes the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the operation in the front-rear direction to the pilot port of the control valve 175. More specifically, when the right operation lever 26R is operated in the boom raising direction (rear direction), 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. Also, when the right operation lever 26R is operated in the boom lowering direction (front direction), 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, in the form of pressure, the content of the operation in the front - rear direction of the right operation lever 26R by the operator, and outputs the detected value to the controller 30.

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

[0088] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right - hand pilot port of the control valve 175L and the left - hand 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. Also, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right - hand 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] Also, as shown in FIG. 3D, the right operation lever 26R is also used to operate the bucket 6. Specifically, the right operation lever 26R utilizes the hydraulic oil discharged by the pilot pump 15 and applies a pilot pressure corresponding to the operation in the left - right direction to the pilot port of the control valve 174. More specifically, when the right operation lever 26R is operated in the bucket closing direction (left direction), it applies a pilot pressure corresponding to the operation amount to the left - hand pilot port of the control valve 174. Also, when the right operation lever 26R is operated in the bucket opening direction (right direction), it applies a pilot pressure corresponding to the operation amount to the right - hand pilot port of the control valve 174.

[0090] The operation pressure sensor 29RB detects the content of the left - right direction operation on the right operation lever 26R 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 the current command output by the controller 30. And the proportional valve 31DL adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 through the proportional valve 31DL and the shuttle valve 32DL to the left - hand pilot port of the control valve 174. The proportional valve 31DR operates in response to the current command output by the controller 30. And the proportional valve 31DR adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 through the proportional valve 31DR and the shuttle valve 32DR to the right - hand pilot port of the control valve 174. The proportional valves 31DL, 31DR can adjust the pilot pressure so that the control valve 174 can be stopped at an arbitrary valve position.

[0092] 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 174 via the proportional valve 31DL and the shuttle valve 32DL, regardless of the bucket closing operation by the operator. That is, the controller 30 can automatically close the bucket 6. Also, the controller 30 can supply the hydraulic oil discharged by the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31DR and the shuttle valve 32DR, regardless of the bucket opening operation by the operator. That is, the controller 30 can automatically open the bucket 6.

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

[0094] Next, with reference to FIG. 4, the functions of the controller 30 will be described. 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 an attitude detection device, an operation device 26, an object detection device 70, an imaging device 80, a switch NS, etc., execute various calculations, and output control commands to the proportional valve 31, a display device D1, a 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 body inclination sensor S4, and a turning 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 by hardware or may be configured by software.

[0095] The trajectory generation unit 30A is configured to generate a target trajectory, which is a trajectory traced by a predetermined part of the excavator 100 when the excavator 100 operates autonomously. The predetermined part is, for example, the tip of the bucket 6 or a predetermined point on the back surface of the bucket 6. In the present embodiment, the trajectory generation unit 30A generates a target trajectory to be used when the autonomous control unit 30B operates the excavator 100 autonomously. Specifically, the trajectory generation unit 30A generates a 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 operate the excavator 100 autonomously. In the present embodiment, the autonomous control unit 30B is configured to move a predetermined part of the excavator 100 along the target trajectory generated by the trajectory generation unit 30A when a predetermined start condition is satisfied. Specifically, the autonomous control unit 30B operates the excavator 100 autonomously so that a predetermined part of the excavator 100 moves along the target trajectory when the operating device 26 is operated while the switch NS is pressed. For example, when the left operation lever 26L is operated in the arm opening direction while the switch NS is pressed, the autonomous control unit 30B operates the excavation attachment AT so that the tip of the bucket 6 moves along the target trajectory.

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

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

[0099] Thereafter, the controller 30 calculates the three-dimensional coordinates (Xer, Yer, Zer) of the control reference point after the elapse of a unit time 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 the elapse of a unit time are, for example, coordinates on the target trajectory. The unit time is, for example, a time corresponding to an integer multiple of the control cycle.

[0100] The target trajectory may be, for example, a target trajectory related to the dumping operation (soil discharging operation) executed in the loading operation which is an operation for realizing the loading of earth and sand or the like onto the dump truck. The dumping operation includes an operation of dumping (lowering) the excavated material such as earth and sand taken into the bucket 6 onto the loading platform of the dump truck. Typically, the dumping operation is a combined operation including a bucket opening operation and an arm opening operation. In this case, the target trajectory may be calculated based on at least one of, for example, the shape of the dump truck (for example, the length in the front-rear direction of the loading platform of the dump truck and the orientation of the loading platform), the shape of the loaded material such as earth and sand already loaded on the loading platform of the dump truck, and the volume of the excavated material taken into the bucket 6. Note that the shape of the dump truck, the shape of the loaded material, and the volume of the excavated material taken into 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.

[0101] For example, the target trajectory is set such that when the excavated material taken into the bucket 6 is dumped onto the loading platform of the dump truck, the height of the newly formed loaded material by the excavated material becomes substantially constant. Specifically, the target trajectory is set such that a substantially rectangular parallelepiped loaded material having a width Wt, a length Lt, and a height Ht is formed.

[0102] The target trajectory is typically calculated before the earthmoving operation starts and is not changed until the earthmoving operation ends. However, the target trajectory may be changed during the execution of the earthmoving operation. For example, the target trajectory may be adjusted downward 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 be feedback-controlled according to the height of the newly formed load. Note that the height of the newly formed load is calculated based on the output of at least one of, for example, the object detection device 70 and the imaging device 80.

[0103] Thereafter, based on the calculated three-dimensional coordinates (Xer, Yer, Zer), the controller 30 determines command values β 1r , β 2r , and β 3r for the rotation of the boom 4, the arm 5, and the bucket 6, and a command value α 1r for the rotation of the upper swing body 3. The command value β 1r represents, for example, 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), 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 swing angle α1 when the control reference point can be aligned with the three-dimensional coordinates (Xer, Yer, Zer).

[0104] The command value β 3r for the rotation of the bucket 6 may be changed during the execution of the earthmoving operation. For example, the command value β 3r may be adjusted downward if the height of the newly formed load is greater than the desired height. That is, the command value β 3r is typically controlled by open-loop control, but may be feedback-controlled according to the height of the newly formed load.

[0105] When a target trajectory regarding the soil discharging operation is calculated, typically, the generation of the command value α 1r is omitted. This is because the soil discharging operation is typically performed with the swing angle α1 fixed.

[0106] Thereafter, as shown in FIG. 6, the controller 30 operates the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the swing hydraulic motor 2A so that each of the boom angle β1, the arm angle β2, the bucket angle β3, and the swing angle α1 becomes the generated command values β1r, β2r, β3r, and α1r. Note that 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 measured in advance and input.

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

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

[0109] At this time, the controller 30 may generate a boom spool control command based on the spool displacement amount of the control valve 175 detected by the boom spool displacement sensor S7. The boom spool displacement sensor S7 is a sensor that detects the displacement amount of the spool constituting the control valve 175. Then, the controller 30 may output a control current corresponding to the boom spool control command to the boom control mechanism 31C. In this case, the boom control mechanism 31C acts on the control valve 175 with a pilot pressure corresponding to the control current corresponding to the boom spool control command.

[0110] The boom cylinder 7 expands and contracts by the hydraulic oil supplied through the control valve 175. The boom angle sensor S1 detects the boom angle β1 of the boom 4 moved by the expanding and contracting boom cylinder 7.

[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 used when generating the boom cylinder pilot pressure command.

[0112] The above description relates to the operation of the boom 4 based on the command value β1r, but it is similarly applicable 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 slewing operation of the upper slewing body 3 based on the command value α1r. Note that the arm control mechanism 31A is configured to be able to apply a pilot pressure corresponding to the control current corresponding to the arm cylinder pilot pressure command to the control valve 176 as the arm control valve. The arm control mechanism 31A may be, for example, the proportional valves 31AL and 31AR in FIG. 3A. Also, the bucket control mechanism 31D is configured to be able to apply a pilot pressure corresponding to the control current corresponding to the bucket cylinder pilot pressure command to the control valve 174 as the bucket control valve. The bucket control mechanism 31D may be, for example, the proportional valves 31DL and 31DR in FIG. 3D. Also, the slewing control mechanism 31B is configured to be able to apply a pilot pressure corresponding to the control current corresponding to the slewing hydraulic motor pilot pressure command to the control valve 173 as the slewing control valve. The slewing control mechanism 31B may be, for example, the proportional valves 31BL and 31BR in FIG. 3B. Also, the arm spool displacement sensor S8 is a sensor that detects the displacement amount of the spool constituting the control valve 176, the bucket spool displacement sensor S9 is a sensor that detects the displacement amount of the spool constituting the control valve 174, and the slewing spool displacement sensor S6 is a sensor that detects the displacement amount of the spool constituting the control valve 173.

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

[0114] In this way, the controller 30 can simultaneously execute the opening control of each of the control valve 175 as the boom control valve, the control valve 176 as the arm control valve, the control valve 174 as the bucket control valve, and the control valve 173 as the swing control valve, and the control of the discharge amount 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] Further, the controller 30 calculates the three-dimensional coordinates (Xer, Yer, Zer) and the command value β 1r , β 2r , β 3r , and α 1rThe generation and the determination of the discharge amount of the main pump 14 are regarded as one control cycle, and autonomous control is executed by repeating this control cycle. Further, the controller 30 can improve the accuracy of autonomous control by performing feedback control on 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 turning angular velocity sensor S5. Specifically, the controller 30 can improve the accuracy of autonomous control by performing feedback control on the flow rate of the hydraulic oil flowing into each of the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the turning hydraulic motor 2A.

[0116] Further, when the controller 30 executes autonomous control related to the soil discharging operation, it 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. For example, when the controller 30 determines based on the outputs 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 is less than a predetermined value, or when it determines that the distance between the tip of the bucket 6 and the bottom surface of the loading platform of the dump truck is less than a predetermined value, the movement of the excavation attachment AT may be stopped.

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

[0118] For clarity, FIGS. 7A to 7C show the front panel FR and the rear gate RG of the dump truck DT while omitting the illustration of the left and right side gates. For clarity, FIG. 7D shows the left side gate LSG and the right side gate RSG while omitting the illustration of the front panel FR and the rear gate RG. Further, in FIGS. 7B to 7D, the illustration of the overall image of the dump truck DT is omitted.

[0119] Specifically, FIG. 7A shows the state of the loading platform BD of the dump truck DT in a state where no excavated material such as earth and sand is loaded. Further, FIG. 7A shows the bucket 6 in a state where the excavated material is taken in and positioned above the loading platform BD by manual operation or autonomous control as the bucket 6a. Further, the bucket 6a shows the state of the bucket 6 when the boom raising and slewing operation executed after the excavation operation is completed. And the point Pa represents the tip position of the bucket 6 when the boom raising and slewing operation is 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 dumping start point Ps1 and a dumping end point Pe1 are set. Then, a target trajectory TL is obtained as a virtual line segment connecting the dumping start point Ps1 and the dumping end point Pe1. And an opening angle of the bucket 6 is calculated so as to correspond to the position of this target trajectory TL. Thereby, corresponding to the arm opening control started when the tip of the bucket 6 is at the dumping start point Ps1, boom raising control and bucket opening control are executed so that the tip of the bucket 6 follows the target trajectory TL. Then, when the arm 5 becomes perpendicular to the bed BD, the boom raising control switches to boom lowering control. That is, when the arm opening control is executed at a predetermined speed as master control, the boom control and the bucket control are executed as slave control accordingly. In this way, the movement of the tip of the bucket 6 is controlled to follow the target trajectory TL. Bucket opening control may be executed as master control. In this case, the arm control and the boom control are executed as slave control. 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 learning data for each earth and sand characteristic and working environment, etc.

[0121] The target trajectory TL1 regarding the first dumping operation is an example of the target trajectory TL, and is represented as a virtual line segment connecting the dumping start point Ps1 and the dumping end point Pe1, which is at a height H1 from the bottom surface of the bed BD.

[0122] The dumping start point Ps1 is the starting point of the target trajectory TL1. The dumping start point Ps1 is set at a position separated forward by an interval RS from the rear gate RG. The value of the interval RS is, for example, stored in advance in the non-volatile memory device. Also, the dumping start point Ps1 is set so as to pass through the center of the width of the bed BD.

[0123] The soil discharge end point Pe1 is the end point of the target trajectory TL1. The soil discharge end point Pe1 is set at a position that is separated rearward from the front panel FR by an interval FS. The value of the interval FS is, for example, prestored in a nonvolatile memory device. Also, the soil discharge end point Pe1 is set so as 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 soil discharge start point Ps1 and the soil discharge end point Pe1, is an example of the length Lt, and is a value obtained by subtracting the interval RS and the interval FS from the loading platform length Lb of the dump truck DT.

[0125] The height H1 is an example of the height Ht, and is calculated based on, for example, the volume of the excavated material taken into the bucket 6a. Specifically, the height H1 is calculated such that the volume of the rectangular parallelepiped represented by the product of the length Lt (L1), the height Ht (H1), and the width Wt is equal to the volume of the excavated material taken into 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 prestored in a nonvolatile memory device. The volume of the excavated material taken into the bucket 6a is calculated based on the output of at least one of the object detection device 70 and the imaging device 80, for example.

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

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

[0128] Typically, the controller 30 executes bucket opening control such that the bucket angle β3 increases as the tip of the bucket 6 approaches the soil discharge end point Pe1. When determining the bucket angle β3, the controller 30 may consider the characteristics of the material to be excavated, such as the viscosity of the soil and sand. The characteristics of the material to be excavated may be dynamically calculated based on the output of at least one of the object detection device 70 and the imaging device 80, or may be pre-stored in the non-volatile memory device.

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

[0130] In the example shown in FIGS. 7A to 7D, the controller 30 executes bucket opening control such that the rear surface BF of the bucket 6 is parallel to the front panel FR when the tip of the bucket 6 is located at the soil discharge end point Pe1, or such that the bucket angle β3 is larger than the angle θ4 when the rear surface BF of the bucket 6 is 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 soil discharging operation. Specifically, Figure 7B shows the shape of the loaded material LD formed when the controller 30 executes the bucket opening control while moving the tip of the bucket 6 along the target trajectory TL1, that is, the shape of the loaded material LD1 formed by the first soil discharging operation. The loaded material LD1 has substantially the same shape as a rectangular parallelepiped with a length L1, a width Wt, and a height H1. Figure 7B shows the shape of the loaded material LD1 formed by the first soil discharging operation in a cross pattern.

[0132] The target trajectory TL2 for the second soil discharging operation is an example of the target trajectory TL, and is represented as a virtual line segment connecting the soil discharging start point Ps2 and the soil discharging end point Pe2, which is at a height H2 from the upper surface of the loaded material LD1.

[0133] The height of the upper surface of the loaded material LD1 with respect to the bottom surface of the loading platform BD is calculated based on, for example, 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 loaded material LD1 may be the height H1 calculated immediately before the first soil discharging operation.

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

[0135] The soil discharging end point Pe2 is the end point of the target trajectory TL2. The soil discharging end point Pe2 is set at a position separated rearward by a distance FS 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 soil discharging start point Ps2 and the soil discharging end point Pe2, is an example of the length Lt, and is a value obtained by subtracting the distance RS and the distance FS from the loading platform length Lb of the dump truck DT.

[0137] The height H2 is an example of the height Ht, and is calculated based on, for example, the volume of the excavated material taken into the bucket 6 immediately before the second dumping operation is performed. Specifically, the height H2 is calculated such that the volume of the rectangular parallelepiped represented by the product of the length Lt (L2), the height Ht (H2), and the width Wt is equal to the volume of the excavated material taken into the bucket 6 immediately before the second dumping operation is performed.

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

[0139] Figures 7C and 7D show the state of the loading platform BD immediately after the second dumping operation is performed. Specifically, Figures 7C and 7D show the shape of the load LD formed when the controller 30 executes bucket opening control while moving the tip of the bucket 6 along the target trajectory TL2, that is, the combination of the load LD1 formed by the first dumping operation and the load LD2 formed by the second dumping operation. The load LD2 has substantially the same shape as a rectangular parallelepiped with a length L2, a width Wt, and a height H2. Figures 7C and 7D show the shape of the load LD2 formed by the second dumping operation with a downward-sloping diagonal pattern.

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

[0141] Further, the controller 30 may generate a virtual line segment connecting the point Pa and the dumping start point Ps1 as an approach trajectory TLa that is a part of the target trajectory TL. The point Pa represents the tip position of the bucket 6 when the boom raising and slewing operation is completed.

[0142] Further, the controller 30 may generate a virtual line segment connecting the dumping end point Pe1 and the point Pf as a retreat trajectory TLw that is another part of the target trajectory TL. The point Pf represents the tip position of the bucket 6 when the boom lowering and slewing operation starts.

[0143] Further, the controller 30 may be configured to set the end position of the boom raising and slewing operation, the target trajectory TL for the dumping operation, etc. between the left side gate LSG and the right side gate RSG. Also, when the control reference point is set at the center of the bucket 6 in the left-right direction, the controller 30 may be configured to set the target trajectory TL for the dumping operation at the middle 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 dumping operation. Therefore, even if the operator of the excavator 100 is not skilled in the dumping operation, the operator can perform the dumping operation in the same manner as a skilled operator. Accordingly, the controller 30 can improve the working efficiency of the excavator 100. Further, the controller 30 can prevent a situation in which, for example, the excavated material is dumped from a high position onto the loading platform BD of the dump truck DT by an unskilled operator and the excavated material spills from the loading platform BD.

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

[0146] For clarity, FIGS. 8A to 8E show the front panel FR and the rear gate RG of the dump truck DT while omitting the illustration of the left side gate and the right side gate. Further, FIGS. 8A to 8E omit the illustration of the overall image of the dump truck DT as in FIGS. 7B and 7C.

[0147] FIG. 8A shows the loading platform BD of the dump truck DT in a state where no excavated material such as earth and sand is loaded. The target trajectory TL1 related to the first dumping operation shown in FIG. 8A is an example of the target trajectory TL and is represented as a virtual line segment connecting the dumping start point Ps1 and the dumping end point Pe1, which is at a height H1 from the bottom surface of the loading platform BD.

[0148] The height H1 is an example of the height Ht, and is calculated based on, for example, the volume of the excavated material taken into the bucket 6 immediately before the first dumping operation. Specifically, the height H1 is calculated such that the volume of the rectangular parallelepiped represented by the product of the length Lt (L1), the height Ht (H1), and the width Wt is equal to the volume of the excavated material taken into the bucket 6 immediately before the first dumping operation. The width Wt is a value corresponding to the width of the bucket 6 and is, for example, stored in advance in a non-volatile memory device.

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

[0150] FIG. 8B shows the state of the loading platform BD immediately after the first dumping operation. Specifically, FIG. 8B shows the shape of the load LD1 formed by the first dumping operation in a cross pattern.

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

[0152] The height H2 is an example of the height Ht, and is calculated based on, for example, the volume of the excavated material taken into the bucket 6 immediately before the second dumping operation. Specifically, the height H2 is calculated such that the volume of the rectangular parallelepiped represented by the product of the length Lt (L2), the height Ht (H2), and the width Wt is equal to the volume of the excavated material taken into the bucket 6 immediately before the second dumping operation.

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

[0154] FIG. 8C shows the state of the loading platform BD immediately after the second dumping operation. Specifically, FIG. 8C shows the shape of the load LD2 formed by the second dumping operation with a downward-sloping diagonal pattern.

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

[0156] The height H3 is an example of the height Ht, and is calculated, for example, based on the volume of the excavated material taken into the bucket 6 immediately before the third dumping operation. Specifically, the height H3 is calculated such that the sum of the volume of a rectangular parallelepiped represented by the product of the length Lt (L3), the height Ht (H3), and the width Wt and the volume of the space SP1 is equal to the volume of the excavated material taken into the bucket 6 immediately before the third dumping operation.

[0157] The space SP1 is a space capable of accommodating the excavated material, which is between the load LD already loaded on the loading platform BD and the rear gate RG. 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 the non-volatile memory device.

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

[0159] Further, when the tip of the bucket 6 reaches the soil discharge start point Ps3, the controller 30 executes bucket swing control before moving the tip of the bucket 6 along the target trajectory TL3.

[0160] The bucket swing control is control to drop a part of the excavated material taken into the bucket 6 into the space SP1 and fill the space SP1 with the excavated material.

[0161] Specifically, the controller 30 slightly opens and closes the bucket 6 one or more times, that is, slightly extends and retracts the bucket cylinder 9 one or more times, so that a part of the excavated material lifted by the bucket 6 jumps out of the bucket 6.

[0162] The controller 30 may swing the bucket 6 by moving at least one of the boom 4, the arm 5, and the bucket 6 one or more times, so that a part of the excavated material lifted by the bucket 6 jumps out of the bucket 6.

[0163] In the present embodiment, regardless of whether the space SP1 is filled with a part of the excavated material lifted by the bucket 6, when the bucket 6 is swung a predetermined number of times, the controller 30 starts moving the tip of the bucket 6 along the target trajectory TL3. However, the controller 30 may continue to swing the bucket 6 until it is confirmed that the space SP1 is filled with a part of the excavated material. In this case, the controller 30 may determine whether the space SP1 is filled with a part of the excavated material 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 soil discharge operation. Specifically, FIG. 8D shows the shape of the loaded material LD3 formed by the third soil discharge operation in a dot pattern.

[0165] The target trajectory TL4 for the fourth earth-discharging operation is an example of the target trajectory TL, and is represented as a virtual line segment connecting a soil-discharging start point Ps4 and a soil-discharging end point Pe4, which is at a height H4 slightly lower than the upper surface of the load LD3. Note that the height H4 is the height from the bottom surface of the vehicle body BD.

[0166] The height H4 is an example of the height Ht and is calculated based on, for example, the height of the upper surface of the load LD3. Note that the fourth earth-discharging operation is performed to level the upper surface of the load LD already loaded on the vehicle body BD with the back surface of the bucket 6 and to push a part of the excavated material above the load LD with the back surface of the bucket 6 to drop a part of the excavated material into the space SP2 to fill the space SP2. Therefore, the fourth earth-discharging operation is performed with the bucket 6 in an empty state, that is, in a state where no excavated material is taken into the bucket 6.

[0167] The space SP2 is a space capable of accommodating the excavated material, which is between the load LD already loaded on the vehicle body BD and the front panel FR.

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

[0169] FIG. 8E shows the state of the vehicle body BD immediately after the fourth earth-discharging operation is performed. Specifically, FIG. 8E shows the shape of the load LD in a state where the upper surface is leveled and the space SP2 is filled with the excavated material by the fourth earth-discharging operation. 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 earth-discharging operation by the operator. Therefore, even when the operator of the excavator 100 is not skilled in the earth-discharging operation, the operator can perform the earth-discharging operation in the same manner as a skilled operator. Therefore, the controller 30 can improve the working efficiency of the excavator 100.

[0171] Next, with reference to FIGS. 9A to 9E, another example of autonomous control regarding the soil discharging operation will be described. FIGS. 9A to 9E are side views of the loading platform BD of the dump truck DT when the soil discharging operation is performed. Specifically, FIG. 9A is a side view of the loading platform BD immediately before the soil discharging operation is performed. FIG. 9B is a side view of the loading platform BD immediately after the first soil discharging operation is performed. FIG. 9C is a side view of the loading platform BD immediately after the second soil discharging operation is performed. FIG. 9D is a side view of the loading platform BD immediately after the third soil discharging operation is performed. FIG. 9E is a side view of the loading platform BD immediately after the fourth soil discharging operation is performed.

[0172] For clarity, FIGS. 9A to 9E show the front panel FR and the rear gate RG of the dump truck DT while omitting the illustration of the left side gate and the right side gate. Also, FIGS. 9A to 9E omit the illustration of the overall image of the dump truck DT, similar to FIGS. 7B, 7C, and 8A to 8E.

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

[0174] The height H1 is an example of the height Ht, and is calculated based on, for example, the volume of the excavated material taken into the bucket 6 immediately before the first soil discharging operation is performed. Specifically, the height H1 is calculated such that the volume of the rectangular parallelepiped represented by the product of the length Lt (L1), the height Ht (H1), and the width Wt is equal to the volume of the excavated material taken into the bucket 6 immediately before the first soil discharging operation is performed. The width Wt is a value corresponding to the width of the bucket 6 and is, for example, pre-stored in the non-volatile memory device.

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

[0176] FIG. 9B shows the state of the loading platform BD immediately after the first soil discharging operation. Specifically, FIG. 9B shows the shape of the load LD1 formed by the first soil discharging operation in a cross pattern.

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

[0178] The height H2 is an example of the height Ht, and is calculated based on, for example, the height of the upper surface of the load LD1. Note that the second soil discharging operation is performed to load the excavated material taken into the bucket 6 onto the loading platform BD, level the upper surface of the load LD1 already loaded on the loading platform BD with the back surface of the bucket 6, and push a part of the excavated material located above the load LD with the back surface of the bucket 6 to drop a part of the excavated material into the space SP3 and fill the space SP3.

[0179] The space SP3 is a space capable of accommodating the excavated material, which is between the load LD1 already loaded on the loading platform BD and the front panel FR.

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

[0181] Figure 9C shows the state of the loading platform BD immediately after the second dumping operation. Specifically, Figure 9C shows the shape of the load LD2 formed by the second dumping operation with a downward-sloping diagonal pattern.

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

[0183] The height H3 is an example of the height Ht, and is calculated based on, for example, the height of the upper surface of the load LD2. Note that the third dumping operation is performed to load the material to be excavated taken into the bucket 6 onto the loading platform BD, level the upper surface of the load LD2 already loaded on the loading platform BD with the back of the bucket 6, and push a part of the material to be excavated at the upper part of the load LD2 with the back of the bucket 6 to drop a part of the material to be excavated into the space SP4 to fill the space SP4.

[0184] The space SP4 is a space capable of accommodating the object to be excavated, which is between the load LD already loaded on the loading platform BD and the front panel FR.

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

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

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

[0188] The bucket swing control is control to drop a part of the object to be excavated taken into the bucket 6 into the space SP5 and fill the space SP5 with the object to be excavated.

[0189] The space SP5 is a space capable of accommodating the object to be excavated, which is between the load LD already loaded on the loading platform BD and the rear gate RG.

[0190] Specifically, the controller 30 slightly opens and closes the bucket 6 one or more times, that is, slightly extends and retracts the bucket cylinder 9 one or more times, so that a part of the object to be excavated lifted by the bucket 6 jumps out of the bucket 6.

[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, so that a part of the object to be excavated lifted by the bucket 6 jumps out of the bucket 6.

[0192] In this embodiment, regardless of whether the space SP5 is filled with a part of the excavated material taken into the bucket 6, when the bucket 6 is swung a predetermined number of times, the controller 30 starts the movement of the tip of the bucket 6 along the target trajectory TL3. However, the controller 30 may continue to swing the bucket 6 until it is confirmed that the space SP5 is filled with a part of the excavated material. In this case, the controller 30 may determine whether the space SP1 is filled with a part of the excavated material 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 dumping operation. Specifically, FIG. 9D shows the shape of the load LD3 formed by the third dumping operation in a dot pattern.

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

[0195] The height H4 is an example of the height Ht, and is calculated based on, for example, the height of the upper surface of the load LD3. The fourth dumping operation is performed to level the upper surface of the load LD3 already loaded on the loading platform BD with the back surface of the bucket 6, and to push a part of the excavated material above the load LD3 with the back surface of the bucket 6 so that a part of the excavated material falls into the space SP6 and fills the space SP6. Therefore, the fourth dumping operation is performed with the bucket 6 in an empty state, that is, a state in which no excavated material is taken into the bucket 6.

[0196] The space SP6 is a space capable of accommodating the excavated material, which is between the load LD already loaded on the loading platform BD and the front panel FR.

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

[0198] FIG. 9E shows the state of the loading platform BD immediately after the fourth dumping operation. Specifically, FIG. 9E shows the shape of the load LD in a state where the upper surface has been leveled by the fourth dumping operation and the space SP6 is filled with the excavated material. 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 dumping operation. Therefore, even if the operator of the excavator 100 is not skilled in the dumping operation, the operator can perform the dumping operation in the same manner as a skilled operator. Accordingly, the controller 30 can improve the working efficiency of the excavator 100.

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

[0201] The target trajectory TL is preferably set along the front-rear direction of the dump truck DT. Further, the target trajectory TL is set to a predetermined height along the bottom surface of the loading platform BD of the dump truck DT. With this configuration, the controller 30 can efficiently dump the excavated material taken into the bucket 6 onto the loading platform 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 cargo 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 cargo bed BD of the dump truck DT. With this configuration, the controller 30 can make the height of the load LD loaded on the cargo bed BD of the dump truck DT even 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 and the dump truck DT from coming into contact when performing autonomous control related to the soil discharging operation.

[0205] Here, the operation flow of the "excavation and loading operation" of the excavator 100 will be described with reference to FIG. 13. FIG. 13 is an explanatory diagram for explaining the operation flow of the "excavation and loading operation" of the excavator 100.

[0206] FIGS. 13(A) to 13(D) show a state in which the excavation operation is being performed. The section where the excavation operation is performed is referred to as the excavation operation section. The excavation operation is divided into the first half excavation operation in FIGS. 13(A) and 13(B) and the second half excavation operation in FIGS. 13(C) and 13(D).

[0207] As shown in Fig. 13(A), the controller 30 positions the tip of the bucket 6 so that the tip of the bucket 6 reaches a desired height position with respect to the excavation target (soil and sand in this example), and closes the arm 5 from the state where the arm 5 is open as shown in Fig. 13(A) until the arm 5 becomes substantially perpendicular to the ground as shown in Fig. 13(B). By this operation, soil and sand of a certain depth are excavated, and the soil and sand are scraped together until the arm 5 becomes substantially perpendicular to the ground surface. The above operations are referred to as the first half excavation operations, and this operation section is referred to as the first half excavation operation section.

[0208] Thereafter, as shown in Fig. 13(C), the controller 30 further closes the arm 5 to scrape the soil and sand further with the bucket 6. Then, as shown in Fig. 13(D), the controller 30 closes the bucket 6 until the upper edge becomes substantially horizontal to store the scraped soil and sand in the bucket 6. Also, the controller 30 raises the boom 4 to raise the bucket 6 to the position shown in Fig. 13(D). The above operations are referred to as the second half excavation operations, and this operation section is referred to as the second half 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 being substantially horizontal, the controller 30 raises the boom 4 until the bottom of the bucket 6 reaches a desired height from the ground as shown in Fig. 13(E). The desired height is, for example, a height equal to or higher than the height of the rear gate RG of the dump truck DT. The controller 30, following or simultaneously with this operation, rotates the upper swing body 3 as indicated by the arrow and moves the bucket 6 to the position for discharging the soil.

[0210] Thereafter, when the controller 30 completes the boom raising and swinging operation, next, as shown in Fig. 13(F), the controller 30 opens the arm 5 and the bucket 6 to discharge the soil in the bucket 6 onto the loading platform BD of the dump truck DT. In this soil discharging operation (dumping operation), the controller 30 may discharge the soil by opening only the bucket 6.

[0211] When the controller 30 completes the dumping operation, next, as shown in Fig. 13(G), the upper swing body 3 is swung as indicated by the arrow, and the bucket 6 is moved directly above the excavation position. At this time, the controller 30 lowers the boom 4 simultaneously with the swing and lowers the bucket 6 to a desired height from the excavation target. Then, the controller 30 lowers the bucket 6 to a desired height as shown in Fig. 13(A) and performs the excavation operation again.

[0212] The target trajectory TL may be set according to the progress of the work for each of the excavation operation section, the boom raising and swinging operation section, the dumping operation section, and the boom lowering and swinging operation section. For example, the controller 30 sets the target trajectory TL in the excavation operation section and the target trajectory TL in the dumping operation section, and calculates the target trajectory TL in the boom raising and swinging operation section so as to connect the start point of the dumping operation section and the end point of the excavation operation section, and calculates the target trajectory TL in the boom lowering and swinging 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 soil discharge start point Ps1 and the soil discharge end point Pe1 based on the position of the cargo bed BD of the dump truck DT recognized as described above. Then, the target trajectory TL in the dumping operation section is updated each time the 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 shape of the earth and sand (such as the terrain shape, the embankment shape, or the shape of the temporarily placed earth and sand mound) each time the excavation operation is performed. The controller 30 may calculate the shape of the earth and sand based on the trajectory of the bucket tip, or may calculate the shape of the earth and sand based on the detection value of a device capable of detecting the surface shape of the earth and sand, 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 response to the update of the shape of the earth and sand each time the excavation operation is performed. Further, the controller 30 may set the design surface used in the finish excavation as the target trajectory TL in the excavation operation section. The object detection device 70, the imaging device 80, etc. used to acquire the shape of the earth and sand may be installed independently of the excavator 100. Specifically, the object detection device 70, the imaging device 80, etc. may be attached to an aerial photography multi-copter or a tower installed at the work site. Then, the controller 30 may acquire information regarding the shape of the earth and sand at the work site based on an image representing the state when the work site is viewed from above. Also, the target trajectory TL in the excavation operation section may be calculated in consideration of the shape of the bucket 6, the characteristics of the earth and sand, etc. Further, the target trajectory TL in the excavation operation section may be calculated using reinforcement learning (machine learning) based on the shape of the earth and sand before excavation and the target construction surface (design surface). When reinforcement learning is used, the fuel consumption, the working time, etc. may be set as the reward.

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

[0216] The target trajectory TL in the boom raising and slewing operation range is set between the earth discharging start point Ps1 or the boom raising and slewing 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 and slewing operation range 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 advances the "excavation and loading operation" while repeating the cycle composed of the "front half excavation operation", the "rear half excavation operation", the "boom raising and slewing operation", the "dump operation", and the "boom lowering and slewing operation".

[0218] As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions etc. can be applied to the above-described embodiments without departing from the scope of the present invention. Also, the features described separately can be combined as long as no technical contradiction occurs.

[0219] For example, the excavator 100 may execute an autonomous control function as shown below and autonomously execute a combined operation such as an earth discharging 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 by software, may be configured by hardware, or may be configured by 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 the image captured by the imaging device 80 as a surrounding monitoring device. Note that the surrounding monitoring device may be the object detection device 70.

[0221] The function block FB is configured to calculate the height of the loaded material. In the example of FIG. 10, the function block FB calculates the height of the loaded material formed by the excavated material when the excavated material taken into the bucket 6 is dumped onto the loading platform 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 the image captured by the imaging device 80. And when the function block FC determines that the state of the imaging device 80 is abnormal, it outputs a command to the function block F4 described later to decelerate 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 the 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 the 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 at which the bucket 6 containing the excavated material has left the ground. This is to detect the end of the excavation operation.

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

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

[0228] The functional block FH is configured to calculate the total weight of the excavated material loaded on the dump truck DT. In the example of FIG. 10, the functional block FH calculates the total weight of the excavated material already loaded on the bed of the dump truck DT by integrating the weight of the excavated material excavated by each excavation operation, which is calculated by the functional block FG.

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

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

[0231] The functional block FK is configured to calculate the target excavation volume. In the example of FIG. 10, the functional block FK calculates the target excavation volume based on the target excavation weight output by the functional block FJ and the soil information input via the input device 43. The input device 43 is configured to allow the operator to input various information into 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 storage device. The functional block FK calculates the target excavation volume based on, for example, the target excavation weight and the density of the material to be excavated. The functional block FK calculates, for example, the target excavation volume corresponding to a target excavation weight of 3 tons. Basically, even if the target excavation weight is constant (e.g., 3 tons), the smaller the density of the material to be excavated, the larger the target excavation volume.

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

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

[0234] The functional block F1 is typically configured to calculate the target trajectory before each soil discharging operation is started. That is, the target trajectory is typically updated before each soil discharging operation is started. Specifically, the coordinates of the soil discharging start point, which is the start point of the target trajectory, and the coordinates of the soil discharging end point, which is the end point of the target trajectory, are updated before each soil discharging operation is started.

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

[0236] The functional block F1 may cause the display device D1 to display an image related to the target trajectory together with at least one of the rear monitoring image and the surrounding monitoring image. The rear monitoring image is an image for allowing the operator to monitor the rear of the excavator 100, and is generated, for example, based on the image captured by the rear camera 80B. The surrounding monitoring image is an image for allowing the operator to monitor the surroundings of the excavator 100, and is, for example, an overhead image as a viewpoint conversion image generated by synthesizing the images captured by the rear camera 80B, the left camera 80L, and the right camera 80R. The overhead image typically shows the state when the surroundings of the excavator 100 are viewed from a virtual viewpoint directly above. The functional block F1 may cause the display device D1 to display an image related to the target trajectory so as to be 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 regarding the setting state of the hydraulic excavator 100, which is information related to at least one of the engine speed mode, the traveling mode, the type of attachment, and the engine control state. Alternatively, the function block F1 may cause the display device D1 to display an image related to the target trajectory together with information regarding the operating state of the hydraulic excavator, which is information related to at least one of the remaining amount of aqueous urea solution, the remaining amount of fuel, the coolant water temperature, the engine operating time, and the cumulative operating time.

[0238] The function block F2 is configured to calculate the current bucket tip position. In the example of FIG. 10, the function block F2 calculates the coordinate point of the bucket tip of the bucket 6 as the current bucket tip 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 body inclination sensor S4 when calculating the current bucket tip position.

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

[0240] The function block F3 may determine whether the deviation between the current tip position and the target trajectory is within the allowable range. In the example of FIG. 10, the function block F3 determines whether the distance between the current tip position and the target trajectory is equal to or less than a predetermined value. And when 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 tip position. On the other hand, when the distance exceeds the predetermined value, the function block F3 determines that the deviation is not within the allowable range and decelerates 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 speed of the tip. In the example of FIG. 10, based on the current tip position calculated by the function block F2 and the next tip position calculated by the function block F3, the function block F4 calculates, as a command value related to the speed of the tip, the speed of the tip required to move the current tip position to the next tip position in a predetermined time.

[0242] The function block F5 is configured to limit the command value related to the speed of the tip. In the example of FIG. 10, when the function block F5 determines, based on the current tip position calculated by the function block F2 and the image captured by the imaging device 80 as a surrounding monitoring device, that the distance between the tip and a predetermined object such as the dump truck DT is less than a predetermined value, the function block F5 limits the command value related to the speed of the tip to a predetermined upper limit value. In this way, the controller 30 decelerates the speed of the tip when the tip approaches a predetermined object. The function block F5 may be configured to change the upper limit value based on the weight of the excavated material taken into the bucket 6. Alternatively, the function block F5 may be configured to change the upper limit value 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 functional block F6 is configured to calculate command values for operating the actuator. In the example of FIG. 10, the functional block F6 calculates command values β 1r for the boom angle β1, command values β 2r for the arm angle β2, command values β 3r for the bucket angle β3, and command values α 1r for the slewing angle α1 based on the target tip position calculated by the functional block F3 in order to move the current tip position to the target tip position. The functional block F6 calculates the command value β 1r as needed even when the boom 4 is not being operated. This is for automatically operating the boom 4. The same applies to the arm 5, the bucket 6, and the slewing mechanism 2.

[0244] Next, the functional blocks for operating the automatic driving type unmanned excavator will be described. The above-described functional blocks F1 to F6 and FA to FL are used in the same way when operating the automatic driving type unmanned excavator and when operating the manual driving type manned excavator.

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

[0246] The function block FM is configured to determine the start of work. In the example of FIG. 10, when the function block FM receives a start command from the communication device T1, it determines that the start of work is instructed, and is configured to output a start command to the function block FN. When the function block FM receives a start command from the communication device T1, it may be configured to output a start command to the function block FN when it can be determined based on the output of the imaging device 80 as the surrounding monitoring device that there is no object around the excavator 100. When the function block FM outputs a start command to the function block FN, it may output a command to the electromagnetic on-off valve arranged in the 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, based on the current bucket tip position calculated by the function block F2, it is configured to determine which operation among the excavation operation, boom raising and slewing operation, soil discharging operation, and boom lowering and slewing operation, etc. is currently being performed, or whether no operation is being performed. And when the function block FN determines based on the current bucket tip position calculated by the function block F2 that the boom raising and slewing operation has ended, it 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, when the function block FO receives a start command from the function block FN, it is configured to set operating conditions such as the soil discharging speed when the soil discharging operation by autonomous control is performed, and the bucket angle β3 at the start of soil discharging. And after setting the operating conditions, the function block FO is configured to output a start command to the function block FP.

[0249] The functional block FP is configured to determine the start of a predetermined operation. In the example of FIG. 10, when the functional block FP receives a start command from the functional block FO, it determines whether the dumping operation can be started based on the current bucket tip position 6 calculated by the functional block F2. Specifically, the functional block FP determines, based on the current bucket tip position, whether the boom raising and slewing operation has ended, whether the bucket tip of the bucket 6 has reached the dumping start point, and the like. Then, when the functional block FP determines that the boom raising and slewing operation has ended and the bucket tip of the bucket 6 has reached the dumping start point, it determines that the dumping operation can be started. And when the functional block FP determines that the dumping operation can be started, it causes the operation data automatically generated in the autonomous driving type unmanned excavator to be input to the functional block F3.

[0250] With this configuration, the controller 30 can execute the excavation operation by autonomous control in the autonomous driving type unmanned excavator in the same manner as in the manual driving type manned excavator.

[0251] Further, in the above-described embodiment, a hydraulic operation system including a hydraulic pilot circuit is disclosed. Specifically, in the hydraulic pilot circuit related to the operation of the arm 5, the hydraulic oil supplied from the pilot pump 15 to the remote control valve of the left operation lever 26L is transmitted to the pilot port of the control valve 176 as the arm control valve at a flow rate corresponding to the opening degree of the remote control valve that is opened and closed by the operation of the left operation lever in the front-rear direction.

[0252] However, instead of a hydraulic operation system equipped with such a hydraulic pilot circuit, an electric operation system including an electric operation lever equipped with an electric pilot circuit may be adopted. In this case, the lever operation amount of the electric operation lever is input to the controller 30 as an electric signal. Also, 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 according to an electric signal from the controller 30. With this configuration, when a manual operation using the electric operation lever is performed, the controller 30 can control the solenoid valve by 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 constituted by an electromagnetic spool valve. In this case, the electromagnetic spool valve operates according to an electric signal from the controller 30 corresponding to the lever operation amount of the electric operation lever.

[0253] When an electric operation system including an electric operation lever is adopted, the controller 30 can more easily execute an autonomous control function compared to the case where a hydraulic operation system including a hydraulic operation lever is adopted. FIG. 11 shows a configuration example of the electric operation system. Specifically, the electric operation system in FIG. 11 is an example of a boom operation system and mainly includes a control valve unit 17 of a pilot pressure operation type, 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 in FIG. 11 can be similarly applied to an arm operation system, a bucket operation system, and the like.

[0254] The pilot pressure-operated control valve unit 17 includes a control valve 175 (see FIG. 2) for the boom cylinder 7, a control valve 176 (see FIG. 2) for the arm cylinder 8, a control valve 174 (see FIG. 2) for the bucket cylinder 9, and the like. The solenoid valve 65 is configured to be able to adjust the flow passage area of the pipeline connecting the pilot pump 15 and the raising-side pilot port of the control valve 175. The solenoid valve 66 is configured to be able to adjust the flow passage area of the pipeline connecting the pilot pump 15 and the lowering-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) according to the operation signal (electrical signal) output by the operation signal generation unit of the right operation lever 26R. The operation signal output by the operation signal generation unit of the right operation lever 26R is an electrical signal that changes according to the operation amount and operation direction of the right operation lever 26R.

[0256] Specifically, when the right operation lever 26R is operated in the boom raising 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 passage area according to the boom raising operation signal (electrical signal) and controls the pilot pressure as a boom raising operation signal (pressure signal) acting on the raising-side pilot port of the control valve 175. Similarly, when the right operation 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 passage area according to the boom lowering operation signal (electrical signal) and controls the pilot pressure as a boom lowering operation signal (pressure signal) acting on the 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 the autonomous control signal generation unit, instead of in response to an operation signal (electrical signal) output by the operation signal generation unit of the right operation lever 26R, for example. The autonomous control signal may be an electrical signal generated by the controller 30, or may be an electrical signal generated by an external control device or the like other than the controller 30.

[0258] The information acquired by the excavator 100 may be shared with the administrator and operators of other excavators, etc. through an excavator management system SYS as shown in FIG. 12. FIG. 12 is a schematic diagram showing a configuration example of the excavator management system SYS. The management system SYS is a system for managing one or more excavators 100. In the present embodiment, the management system SYS mainly includes an excavator 100, a support device 200, and a management device 300. Each of the excavator 100, the support device 200, and the management device 300 constituting the management system SYS may be one unit or a plurality of units. In the example of FIG. 12, the management system SYS includes one excavator 100, one support device 200, and one management device 300.

[0259] The support device 200 is typically a portable terminal device, such as a notebook PC, a tablet PC, or a smartphone carried by a worker at a construction site, etc. The support device 200 may be a computer carried by the operator of the excavator 100. The support device 200 may 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. The management device 300 may be a portable computer (e.g., a portable terminal device such as a notebook PC, a tablet PC, or a smartphone).

[0261] At least one of the support device 200 and the management device 300 may include a monitor and an operating device for remote operation. In this case, the operator may operate the excavator 100 while using the operating device for remote operation. The operating device for remote operation is connected to the controller 30 through a communication network such as a wireless communication network, for example. Hereinafter, the exchange of information between the excavator 100 and the management device 300 will be described, but the following description is equally applicable to the exchange of information between the excavator 100 and the support device 200.

[0262] In the management system SYS of the excavator 100 as described above, the controller 30 of the excavator 100 may transmit information regarding at least one of the time and location when autonomous control is started or stopped, the target trajectory used during autonomous control, and the trajectory actually traced by a predetermined part during autonomous control to the management device 300. At this time, the controller 30 may transmit, for example, an image captured by the imaging device 80 as a surrounding monitoring device to the management device 300. The image may be a plurality of images captured during a predetermined period including the period during which autonomous control is executed. Further, the controller 30 may transmit information regarding at least one of data regarding the work content of the excavator 100, data regarding the posture of the excavator 100, and data regarding the posture of the excavation attachment AT during a predetermined period including the period during which autonomous control is executed to the management device 300. This is to enable the administrator using the management device 300 to obtain information regarding the work site. The data regarding the work content of the excavator 100 is, for example, at least one of the number of loading operations, which is the number of times the dumping operation is performed, information regarding the excavated material such as the earth and sand loaded on the loading platform of the dump truck DT, the type of the dump truck DT regarding the loading operation, information regarding the position of the excavator 100 when the loading operation is performed, information regarding the work environment, and information regarding the operation of the excavator 100 when the loading operation is being performed. The information regarding the excavated material is, for example, at least one of the weight and type of the excavated material excavated in each excavation operation, the weight and type of the excavated material loaded on the dump truck DT, and the weight and type of the excavated material loaded in the daily loading operation. The information regarding the work environment is, for example, information regarding the slope of the ground around the excavator 100 or information regarding the weather around the work site. The information regarding the operation of the excavator 100 is, for example, at least one of the output of the operation pressure sensor 29 and the output of the cylinder pressure sensor S10.

[0263] In addition, in the above-described embodiment, the autonomous control unit 30B is configured to autonomously assist the manual operation of the excavator 100 by the operator. 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 tip of the bucket 6 coincides with the target trajectory. However, the present invention is not limited to this configuration. For example, 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 tip of the bucket 6 coincides with the target trajectory when the operator is not operating the operation device 26. That is, the autonomous control unit 30B may autonomously move the excavation attachment AT regardless of the operation 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] Further, the controller 30 may be configured to calculate the weight of the excavated material such as earth and sand during the boom raising and slewing operation. For example, the controller 30 calculates the weight of the excavated material based on the balance of two torques around the boom foot pin acting on the boom 4. The two torques are an upward torque (holding torque) acting in the direction of raising the boom 4 and a downward torque (gravity torque) acting in the direction of lowering the boom 4. The holding torque is calculated based on the thrust of the extending boom cylinder 7, and the larger the thrust, the larger the holding torque. The thrust 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 the torque due to the self-weight of the excavation attachment AT and the torque due to the weight of the excavated material. The torque due to the self-weight of the excavation attachment AT is calculated based on the distance between the center of gravity position of the excavation attachment AT and the boom foot pin which is the rotation center of the boom 4 and the self-weight of the excavation attachment AT. The torque due to the weight of the excavated material is calculated based on the distance between the center of gravity position of the excavated material and the boom foot pin and the weight of the excavated material. The center of gravity position of the excavation attachment AT is derived from the posture of the excavation attachment AT. The controller 30 may derive the center of gravity position of the excavation attachment AT by referring to a reference table defining the correspondence between the posture of the excavation attachment AT and the center of gravity position stored in a non-volatile memory device, for example. The posture of the excavation attachment AT is derived based on the output of the posture detection device. The self-weight of the excavation 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 self-weight of the excavation attachment AT by referring to a reference table defining the correspondence between the posture of the excavation attachment AT and the torque due to the self-weight of the excavation attachment AT.

[0265] Then, the controller 30 may calculate, as the torque due to the weight of the material to be excavated among the gravitational torques, the amount obtained by subtracting the torque due to the self-weight of the excavation attachment AT from the magnitude of the holding torque. This is because the magnitude of the holding torque balances the magnitude of the gravitational torque. Further, this is because the gravitational torque is the sum of the torque due to the self-weight of the excavation attachment AT and the torque due to the weight of the material to be excavated.

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

[0267] In the present embodiment, the controller 30 is configured to calculate the weight of the material to be excavated each time the excavation operation ends and the boom-raising swing operation starts. Then, while loading is being performed on the same dump truck DT, the controller 30 integrates the weights of the material to be excavated calculated each time the boom-raising swing operation starts to calculate the total weight of the material to be excavated loaded on the loading platform of the dump truck DT. When the dump truck DT to be loaded is switched, the total weight of the material to be excavated is reset to zero.

[0268] If there is a possibility that the sum of the weight of the material to be excavated actually taken into the bucket 6 and the total weight of the material to be excavated already loaded on the loading platform of the dump truck DT exceeds the maximum loading capacity of the dump truck DT, the controller 30 may interrupt the dumping 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, then calculate the volume of the excess material to be excavated, and interrupt the dumping operation midway so that the material to be excavated of that volume remains in the bucket 6. Then, the controller 30 may execute a leveling operation using the back surface of the bucket 6 while 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, and the entire contents of this Japanese patent application are incorporated herein by reference.

Description of Reference Numerals

[0270] 1 ··· Lower traveling body 1C ··· Crawler 1CL ··· Left crawler 1CR ··· Right crawler 2 ··· Slewing mechanism 2A ··· Slewing hydraulic motor 2M ··· Traveling hydraulic motor 2ML ··· Left traveling hydraulic motor 2MR ··· Right traveling hydraulic motor 3 ··· Upper slewing 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 operation lever 26R ··· Right operation lever 28 ··· Discharge pressure sensor 29, 29DL, 29DR, 29LA, 29LB, 29RA, 29RB ··· Operating pressure sensors 30 ··· Controller 30A ··· Trajectory generation unit 30B ··· Autonomous control unit 31, 31AL~31DL, 31AR~31DR ··· Proportional valve 32, 32AL~32DL, 32AR~32DR ··· Shuttle valve 33, 33AL~33DL, 33AR~33DR ··· Proportional valve 40 ··· Center bypass pipeline 42 ··· Parallel pipeline 43 ··· Input device 65, 66 ··· Solenoid valve 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 ··· Excavator 171~176 ··· Control valve 200 ··· Support device 300 ··· Management device AT ··· Excavation attachment BD ··· Loading platform D1 ··· Display device D2 ··· Sound output device DT ··· Dump truck F1~F6, FA~FP ··· Functional 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 body 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~SP6 ··· Space SYS ··· Management System T1 ··· Communication Device TL, TL1~TL4 ··· Target Orbit

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 a position of the dump truck and generate a target trajectory for the earth-releasing operation, At least a portion of the target trajectory is set at a position lower than the height of a rear gate of the dump truck, The soil-releasing operation is a composite operation including a bucket-opening operation and an arm-opening operation, a start point of the target trajectory is set to a position forward of the release start point, higher than the rear gate, and spaced a predetermined distance forward from the rear gate; The end point of the target trajectory is set to be behind the release end point and higher than the rear gate. Shovel.

2. The target trajectory is set along the longitudinal direction of the dump truck and includes a section extending linearly, The length of the section is greater than the length of the bucket in the front-to-rear direction. The shovel according to claim 1.

3. The target trajectory is set at a predetermined height along the bottom surface of the bed of the dump truck, a height of the target trajectory relative to a bottom surface of the bed of the dump truck or a top surface of a load loaded on the bed of the dump truck is smaller than a depth of an accommodation space of a bucket; The shovel according to claim 1 or 2.

4. The control device sets a bucket angle corresponding to each point on the target trajectory. The shovel according to any one of claims 1 to 3.

5. The control device performs bucket swing control before moving the bucket along the target trajectory, and controls the bucket angle based on the shape of the load loaded on the bed of the dump truck. The shovel according to any one of claims 1 to 4.

6. The control device detects the distance between the back of the bucket and the dump truck. The shovel according to any one of claims 1 to 5.

7. The control device changes the target trajectory for each soil-releasing operation, or determines the height of a newly formed load for each soil-releasing operation. The shovel according to any one of claims 1 to 6.

8. The control device determines the width of the newly formed load for each soil release operation. The shovel according to any one of claims 1 to 7.

9. The control device sets the soil discharge end point to a position a predetermined distance rearward from the front panel. A shovel according to any one of claims 1 to 8.

10. A control device for a shovel having a lower running body and an upper rotating body rotatably mounted on the lower running body, The system is configured to recognize the position of the dump truck and generate a target trajectory for the earth-releasing operation, At least a portion of the target trajectory is set at a position lower than the height of a rear gate of the dump truck, The soil-releasing operation is a composite operation including a bucket-opening operation and an arm-opening operation, a start point of the target trajectory is set to a position forward of the release start point, higher than the rear gate, and spaced a predetermined distance forward from the rear gate; The end point of the target trajectory is set to a position rearward of the release end point and higher than the rear gate. Excavator control device.

11. The target trajectory is changed for each soil-releasing operation, or the height of the newly formed load is determined for each soil-releasing operation. The control device for a shovel according to claim 10.

12. A shovel comprising a lower running body and an upper rotating body rotatably mounted on the lower running 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, At least a portion of the target trajectory is set at a position lower than the height of a rear gate of the dump truck, The soil-releasing operation is a composite operation including a bucket-opening operation and an arm-opening operation, a start point of the target trajectory is set to a position forward of the release start point, higher than the rear gate, and spaced a predetermined distance forward from the rear gate; The end point of the target trajectory is set to a position rearward of the release end point and higher than the rear gate. Excavator management system.

Images