Excavator

Abstract

A shovel (100) according to an embodiment of the present invention includes a lower traveling body (1), an upper rotating body (3) rotatably mounted on the lower traveling body (1), an excavating attachment (AT) provided on the upper rotating body (3), a plurality of actuators for operating the excavating attachment (AT), an operating device (26) provided on the upper rotating body (3), and a controller (30) configured to operate the plurality of actuators in response to operation of the operating device (26) in a first direction to move predetermined portions of the excavating attachment (AT) based on position information. The controller (30) operates the plurality of actuators in a first control mode and a second control mode based on the position information.

Description

Technical Field

[0001] The present disclosure relates to an excavator as a shovel.

Background Art

[0002] Conventionally, a shovel having an excavation control mode for moving a bucket cutting edge along a design surface is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the above-mentioned following excavation control mode is a control for adjusting the relative speed of the bucket cutting edge with respect to the design surface according to the distance between the bucket cutting edge and the design surface, and there is a possibility that the moving speed of the bucket cutting edge moving along the design surface while maintaining the distance between the bucket cutting edge and the design surface cannot be appropriately controlled.

[0005] Therefore, it is desirable to provide an excavator that can more appropriately control the movement of a predetermined part of an attachment along a predetermined trajectory.

Means for Solving the Problems

[0006] The excavator according to an embodiment of the present invention includes a lower traveling body, an upper revolving body rotatably mounted on the lower traveling body, an attachment provided on the upper revolving body, a plurality of actuators for operating the attachment, an operating device provided on the upper revolving body, and a control device configured to operate the plurality of actuators in response to an operation of the operating device in a first direction to move a predetermined part of the attachment based on position information. The control device When moving while aligning the predetermined part with a predetermined orbit,Based on the position information, a plurality of the actuators are operated in a first control mode and a second control mode. make .

Advantages of the Invention

[0007] By the above means, an excavator capable of more appropriately controlling the movement of a predetermined part of an attachment along a predetermined trajectory is provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 5

Figure 6

Figure 7A

Figure 7B

Figure 8

Figure 9A

Figure 9B

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0009] First, with reference to FIGS. 1 and 2, the excavator 100 as a construction machine according to an embodiment of the present invention will be described. FIG. 1 is a side view of the excavator 100, and FIG. 2 is a top view of the excavator 100.

[0010] In the present embodiment, the lower traveling body 1 of the excavator 100 includes crawlers 1C. The crawlers 1C are driven by a traveling hydraulic motor 2M as a traveling actuator mounted on the lower traveling body 1. Specifically, the crawlers 1C include 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 revolving body 3 is rotatably mounted on the lower traveling body 1 via a slewing mechanism 2. The slewing mechanism 2 is driven by a slewing hydraulic motor 2A as a slewing actuator mounted on the upper revolving body 3. However, the slewing actuator may be a slewing electric generator as an electric actuator.

[0012] A boom 4 is attached to the upper revolving 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. The boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 constitute an attachment actuator.

[0013] The boom 4 is supported so as to be rotatable vertically with respect to the upper slewing body 3. A boom angle sensor S1 is attached to the boom 4. The boom angle sensor S1 can detect a boom angle θ1 which is the rotation angle of the boom 4. The boom angle θ1 is, for example, the rising angle from the state where the boom 4 is lowered most. Therefore, the boom angle θ1 becomes maximum when the boom 4 is raised most.

[0014] The arm 5 is supported so as to be rotatable with respect to the boom 4. An arm angle sensor S2 is attached to the arm 5. The arm angle sensor S2 can detect an arm angle θ2 which is the rotation angle of the arm 5. The arm angle θ2 is, for example, the opening angle from the state where the arm 5 is closed most. Therefore, the arm angle θ2 becomes maximum when the arm 5 is opened most.

[0015] The bucket 6 is supported so as to be rotatable with respect to the arm 5. A bucket angle sensor S3 is attached to the bucket 6. The bucket angle sensor S3 can detect a bucket angle θ3 which is the rotation angle of the bucket 6. The bucket angle θ3 is the opening angle from the state where the bucket 6 is closed most. Therefore, the bucket angle θ3 becomes maximum when the bucket 6 is opened most.

[0016] In the embodiment of FIG. 1, each of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 is configured by a combination of an acceleration sensor and a gyro sensor. However, it may be configured by 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 device, 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 a power source such as an engine 11 is mounted thereon. Further, on the upper swing body 3, a space recognition device 70, an orientation detection device 71, a positioning device 73, a machine body inclination sensor S4, a swing angular velocity sensor S5, etc. are attached. Inside the cabin 10, an operation device 26, a controller 30, an information input device 72, a display device D1, a sound output device D2, etc. are provided. In this book, for convenience, the side of the upper swing body 3 where the excavation attachment AT is attached is defined as the front, and the side where the counterweight is attached is defined as the rear.

[0018] The space recognition device 70 is configured to recognize an object existing in the three-dimensional space around the excavator 100. Further, the space recognition device 70 may be configured to calculate the distance to the object recognized from the space recognition device 70 or the excavator 100. The space recognition device 70 includes, for example, an ultrasonic sensor, a millimeter-wave radar, a monocular camera, a stereo camera, LIDAR, a distance image sensor, an infrared sensor, etc. In the present embodiment, the space recognition 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. An upper sensor for recognizing an object existing in the space above the upper swing body 3 may be attached to the excavator 100.

[0019] The orientation detection device 71 is configured to detect information regarding the relative relationship between the orientation of the upper swing body 3 and the orientation of the lower traveling body 1. The orientation detection device 71 may be configured, for example, by a combination of a geomagnetic sensor attached to the lower traveling body 1 and a geomagnetic sensor attached to the upper swing body 3. Alternatively, the orientation detection device 71 may be configured by a combination of a GNSS receiver attached to the lower traveling body 1 and a GNSS receiver attached to the upper swing body 3. The orientation detection device 71 may be a rotary encoder, a rotary position sensor, or the like. In a configuration where the upper swing body 3 is swing-driven by a swing electric generator, the orientation detection device 71 may be configured by a resolver. The orientation detection device 71 may be attached, for example, to a center joint provided in relation to the swing mechanism 2 that realizes relative rotation between the lower traveling body 1 and the upper swing body 3.

[0020] The orientation detection device 71 may be configured by a camera attached to the upper swing body 3. In this case, the orientation detection device 71 performs known image processing on an image (input image) captured by the camera attached to the upper swing body 3 to detect an image of the lower traveling body 1 included in the input image. Then, the orientation detection device 71 uses a known image recognition technique to detect the image of the lower traveling body 1, thereby specifying the longitudinal direction of the lower traveling body 1. Then, an angle formed between the direction of the front-rear axis of the upper swing body 3 and the longitudinal direction of the lower traveling body 1 is derived. The direction of the front-rear axis of the upper swing body 3 is derived from the attachment position of the camera. In particular, since the crawler 1C protrudes from the upper swing body 3, the orientation detection device 71 can specify the longitudinal direction of the lower traveling body 1 by detecting an image of the crawler 1C. In this case, the orientation detection device 71 may be integrated with the controller 30.

[0021] The information input device 72 is configured such that the operator of the excavator can input information to the controller 30. In the present embodiment, the information input device 72 is a switch panel installed close to the display unit of the display device D1. However, the information input device 72 may be a touch panel disposed above the display unit of the display device D1, or may be a sound input device such as a microphone disposed within the cabin 10.

[0022] The positioning device 73 is configured to measure the position of the upper swing body 3. In the present embodiment, the positioning device 73 is a GNSS receiver, which detects the position of the upper swing body 3 and outputs the detected value to the controller 30. The positioning device 73 may be a GNSS compass. In this case, the positioning device 73 can detect the position and orientation of the upper swing body 3.

[0023] The body tilt sensor S4 detects the tilt of the upper swing body 3 with respect to a predetermined plane. In the present embodiment, the body tilt sensor S4 is an acceleration sensor that detects the tilt angles of the upper swing body 3 around the front-rear axis and the left-right axis with respect to the horizontal plane. The front-rear axis and the left-right axis of the upper swing body 3, for example, pass through the excavator center point, which is a point on the swing axis of the excavator 100 and is orthogonal to each other.

[0024] The swing angular velocity sensor S5 detects the swing angular velocity of the upper swing body 3. In the present embodiment, it is a gyro sensor. It may also be a resolver, a rotary encoder, etc. The swing angular velocity sensor S5 may detect the swing speed. The swing speed may be calculated from the swing angular velocity.

[0025] Hereinafter, at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the body tilt sensor S4, and the swing angular velocity sensor S5 is also referred to as an attitude detection device. The attitude of the excavation attachment AT is detected, for example, based on the respective outputs of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3.

[0026] The display device D1 is a device for displaying information. In the present embodiment, the display device D1 is a liquid crystal display installed in the cabin 10. However, the display device D1 may be a display of a portable terminal such as a smartphone.

[0027] The sound output device D2 is a device for outputting sound. The sound output device D2 includes at least one of a device for outputting sound toward an operator inside the cabin 10 and a device for outputting sound toward a worker outside the cabin 10. It may be a speaker of a portable terminal.

[0028] The operation device 26 is a device used by an operator for operating an actuator.

[0029] 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, etc. 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 processing. Each function includes, for example, a machine guidance function for guiding (guiding) the manual operation of the excavator 100 by an operator, and a machine control function for assisting the manual operation of the excavator 100 by an operator or operating the excavator 100 automatically or autonomously.

[0030] Next, referring to FIG. 3, a configuration example of the hydraulic system mounted on the excavator 100 will be described. FIG. 3 is a diagram showing a configuration example of the hydraulic system mounted on the excavator 100. FIG. 3 shows the mechanical power transmission system, the hydraulic oil line, the pilot line, and the electric control system with double lines, solid lines, broken lines, and dotted lines, respectively.

[0031] 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 17, an operation device 26, a discharge pressure sensor 28, an operation pressure sensor 29, a controller 30, etc.

[0032] In FIG. 3, the hydraulic system is configured to be able to circulate hydraulic oil from the main pump 14 driven by the engine 11 to the hydraulic oil tank via the center bypass pipeline 40 or the parallel pipeline 42.

[0033] The engine 11 is a drive source of the excavator 100. In this embodiment, the engine 11 is, for example, a diesel engine that operates to maintain a predetermined 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.

[0034] The main pump 14 is configured to be able to supply hydraulic oil to the control valve 17 via a hydraulic oil line. In this embodiment, the main pump 14 is a swash plate type variable displacement hydraulic pump.

[0035] The regulator 13 is configured to be able to control the discharge amount of the main pump 14. In this embodiment, the regulator 13 controls the discharge amount 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.

[0036] The pilot pump 15 is configured to be able to supply hydraulic oil to hydraulic control equipment including the operating device 26 via a pilot line. In this embodiment, the pilot pump 15 is a fixed displacement hydraulic pump. However, the pilot pump 15 may be omitted. In this case, the function originally performed by the pilot pump 15 may be realized by the main pump 14. That is, in addition to the function of supplying hydraulic oil to the control valve 17, 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 means of a throttle or the like.

[0037] The control valve 17 is a hydraulic control device that controls the hydraulic system in the excavator 100. In this embodiment, the control valve 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 1756. The control valve 17 is configured to selectively supply the hydraulic oil discharged from the main pump 14 to one or more hydraulic actuators through the control valves 171 to 176. The control valves 171 to 176 control, for example, 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 traveling hydraulic motor 2ML, a right traveling hydraulic motor 2MR, and a swing hydraulic motor 2A.

[0038] The operating device 26 is a device used by the operator for operating the actuator. The operating device 26 includes, for example, an operating lever and an operating pedal. The actuator includes at least one of a hydraulic actuator and an electric actuator. In this embodiment, the operating device 26 is configured to supply the hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via a pilot line. The pressure (pilot pressure) of the hydraulic oil supplied to each of the pilot ports is a pressure corresponding to the operating direction and operating amount of the operating device 26 corresponding to each of the hydraulic actuators. However, the operating device 26 may be an electric control type instead of the pilot pressure type as described above. In this case, the control valve in the control valve 17 may be an electromagnetic solenoid type spool valve.

[0039] The discharge pressure sensor 28 is configured to detect the discharge pressure of the main pump 14. In this embodiment, the discharge pressure sensor 28 outputs the detected value to the controller 30.

[0040] The operation pressure sensor 29 is configured to be able to detect the content of the operation of the operation device 26 by the operator. In the present embodiment, the operation pressure sensor 29 detects the operation direction and operation amount of the operation device 26 corresponding to each actuator in the form of pressure (operation pressure), and outputs the detected value to the controller 30. The content of the operation of the operation device 26 may be detected using other sensors other than the operation pressure sensor.

[0041] The main pump 14 includes a left main pump 14L and a right main pump 14R. The left main pump 14L circulates the hydraulic oil to the hydraulic oil tank through the left center bypass pipeline 40L or the left parallel pipeline 42L, and the right main pump 14R circulates the hydraulic oil to the hydraulic oil tank through the right center bypass pipeline 40R or the right parallel pipeline 42R.

[0042] The left center bypass pipeline 40L is a hydraulic oil line that passes through the control valves 171, 173, 175L, and 176L arranged in the control valve 17. The right center bypass pipeline 40R is a hydraulic oil line that passes through the control valves 172, 174, 175R, and 176R arranged in the control valve 17.

[0043] The control valve 171 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the left travel hydraulic motor 2ML and to discharge the hydraulic oil discharged by the left travel hydraulic motor 2ML to the hydraulic oil tank.

[0044] The control valve 172 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the right travel hydraulic motor 2MR and to discharge the hydraulic oil discharged by the right travel hydraulic motor 2MR to the hydraulic oil tank.

[0045] The control valve 173 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the swing hydraulic motor 2A and to discharge the hydraulic oil discharged by the swing hydraulic motor 2A to the hydraulic oil tank.

[0046] The control valve 174 is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the bucket cylinder 9 and to discharge the hydraulic oil in the bucket cylinder 9 to the hydraulic oil tank.

[0047] The control valve 175L is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the boom cylinder 7. The control valve 175R is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the right main pump 14R to the boom cylinder 7 and to discharge the hydraulic oil in the boom cylinder 7 to the hydraulic oil tank.

[0048] The control valve 176L is a spool valve that switches the flow of hydraulic oil to supply the hydraulic oil discharged by the left main pump 14L to the arm cylinder 8 and to discharge the hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.

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

[0050] The left parallel pipeline 42L is a hydraulic oil line parallel to the left center bypass pipeline 40L. The left parallel pipeline 42L can supply hydraulic oil to the downstream control valve 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, 175L. The right parallel pipeline 42R is a hydraulic oil line parallel to the right center bypass pipeline 40R. The right parallel pipeline 42R can supply hydraulic oil to the downstream control valve 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, 175R.

[0051] The regulator 13 includes a left regulator 13L and a right regulator 13R. The left regulator 13L 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 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 amount. The same applies to the right regulator 13R. This is to ensure that the absorbed horsepower of the main pump 14, represented by the product of the discharge pressure and the discharge amount, does not exceed the output horsepower of the engine 11.

[0052] The operating device 26 includes a left operating lever 26L, a right operating lever 26R, and a travel lever 26D. The travel lever 26D includes a left travel lever 26DL and a right travel lever 26DR.

[0053] 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 uses the hydraulic oil discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 176. When the left operating lever 26L is operated in the left-right direction, it uses the hydraulic oil discharged by the pilot pump 15 to introduce a control pressure corresponding to the lever operation amount into the pilot port of the control valve 173.

[0054] Specifically, when the left operating lever 26L is operated in the arm closing direction, it introduces hydraulic oil into the right pilot port of the control valve 176L and also into the left pilot port of the control valve 176R. When the left operating lever 26L is operated in the arm opening direction, it introduces hydraulic oil into the left pilot port of the control valve 176L and also into the right pilot port of the control valve 176R. When the left operating lever 26L is operated in the left turning direction, it introduces hydraulic oil into the left pilot port of the control valve 173, and when it is operated in the right turning direction, it introduces hydraulic oil into the right pilot port of the control valve 173.

[0055] The right operation lever 26R is used for the operation of the boom 4 and 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 introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 175. When the right operation lever 26R is operated in the left-right direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 174.

[0056] Specifically, when the right operation lever 26R is operated in the boom lowering direction, it introduces hydraulic oil into the left pilot port of the control valve 175R. When the right operation lever 26R is operated in the boom raising direction, it introduces hydraulic oil into the right pilot port of the control valve 175L and also into the left pilot port of the control valve 175R. When the right operation lever 26R is operated in the bucket closing direction, it introduces hydraulic oil into the right pilot port of the control valve 174, and when it is operated in the bucket opening direction, it introduces hydraulic oil into the left pilot port of the control valve 174.

[0057] The travel lever 26D is used for the operation of the crawler 1C. Specifically, the left travel lever 26DL is used for the operation of the left crawler 1CL. It may be configured to be interlocked with the left travel pedal. When the left travel lever 26DL is operated in the front-rear direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 171. The right travel lever 26DR is used for the operation of the right crawler 1CR. It may be configured to be interlocked with the right travel pedal. When the right travel lever 26DR is operated in the front-rear direction, it utilizes the hydraulic oil discharged by the pilot pump 15 and introduces a control pressure corresponding to the lever operation amount into the pilot port of the control valve 172.

[0058] 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.

[0059] 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 operation in the front-rear direction 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, the lever operation amount (lever operation angle), etc.

[0060] Similarly, the operation pressure sensor 29LB detects, in the form of pressure, the content of the operation in the left-right direction 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 operation in the front-rear direction 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 operation in the left-right direction 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 operation in the front-rear direction 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 operation in the front-rear direction on the right travel lever 26DR by the operator, and outputs the detected value to the controller 30.

[0061] The controller 30 receives the output of the operation pressure sensor 29, outputs a control command to the regulator 13 as necessary, and changes the discharge amount of the main pump 14. Further, the controller 30 receives the output of the control pressure sensor 19 provided upstream of the throttle 18, outputs a control command to the regulator 13 as necessary, and changes 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.

[0062] 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.

[0063] Specifically, as shown in FIG. 3, in the standby state where none of the hydraulic actuators in the excavator 100 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 discharged hydraulic oil passes through the left center bypass pipeline 40L. On the other hand, when any of the hydraulic actuators are operated, the hydraulic oil discharged by the left main pump 14L flows into the operated hydraulic actuator through the control valve corresponding to the operated hydraulic actuator. 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, circulates sufficient hydraulic oil to the operated hydraulic actuator, and ensures the driving of the operated hydraulic actuator. Note that the controller 30 controls the discharge amount of the right main pump 14R in the same way.

[0064] With the above configuration, in the standby state, the hydraulic system of FIG. 3 can suppress the wasteful energy consumption in the main pump 14. The wasteful 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 of FIG. 3 can surely supply the necessary and sufficient hydraulic oil from the main pump 14 to the hydraulic actuator to be operated.

[0065] Next, referring to FIGS. 4A to 4D, a configuration for the controller 30 to operate the actuator by the machine control function will be described. FIGS. 4A to 4D are partial views of the hydraulic system. Specifically, FIG. 4A is a partial view of the hydraulic system related to the operation of the arm cylinder 8, and FIG. 4B is a partial view of the hydraulic system related to the operation of the boom cylinder 7. FIG. 4C is a partial view of the hydraulic system related to the operation of the bucket cylinder 9, and FIG. 4D is a partial view of the hydraulic system related to the operation of the swing hydraulic motor 2A.

[0066] As shown in FIGS. 4A to 4D, the hydraulic system includes a proportional valve 31 and a shuttle valve 32. The proportional valve 31 includes proportional valves 31AL to 31DL and 31AR to 31DR, and the shuttle valve 32 includes shuttle valves 32AL to 32DL and 32AR to 32DR.

[0067] The proportional valve 31 functions 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 passage area of the pipeline. In this 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 17 via the proportional valve 31 and the shuttle valve 32, regardless of the operation of the operating device 26 by the operator.

[0068] 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 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.

[0069] With this configuration, the controller 30 can operate the hydraulic actuator corresponding to the specific operating device 26 even when an operation on the specific operating device 26 is not being performed.

[0070] For example, as shown in FIG. 4A, 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 (rearward), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 176L and the left pilot port of the control valve 176R. Also, when the left operation lever 26L is operated in the arm opening direction (forward), it applies a pilot pressure corresponding to the operation amount to the left pilot port of the control valve 176L and the right pilot port of the control valve 176R.

[0071] A switch NS is provided on the left operation lever 26L. In this embodiment, the switch NS is a push button switch provided at the tip of the left operation lever 26L. The operator can operate the left operation lever 26L while pressing the switch NS. The switch NS may be provided on the right operation lever 26R or at other positions within the cabin 10.

[0072] The operation pressure sensor 29LA detects the content of the front-rear 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.

[0073] The proportional valve 31AL operates according to the current command output by the controller 30. Then, it adjusts 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 proportional valve 31AL and the shuttle valve 32AL. The proportional valve 31AR operates according to the current command output by the controller 30. Then, it adjusts 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 proportional valve 31AR and the shuttle valve 32AR. The proportional valves 31AL and 31AR can adjust the pilot pressure so that the control valves 176L and 176R can be stopped at any valve position.

[0074] 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 arm 5 can be closed. 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 arm 5 can be opened.

[0075] Also, as shown in Fig. 4B, 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 (rearward), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. Also, when the right operation lever 26R is operated in the boom lowering direction (forward), it applies a pilot pressure corresponding to the operation amount to the right pilot port of the control valve 175R.

[0076] The operation pressure sensor 29RA detects the content of the front-rear 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.

[0077] The proportional valve 31BL operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R via the proportional valve 31BL and the shuttle valve 32BL. The proportional valve 31BR operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure by the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 175L and the right pilot port of the control valve 175R via the proportional valve 31BR and the shuttle valve 32BR. The proportional valves 31BL and 31BR can adjust the pilot pressure so that the control valves 175L and 175R can be stopped at any valve position.

[0078] 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 175L and the left pilot port of the control valve 175R via the proportional valve 31BL and the shuttle valve 32BL, regardless of the boom raising operation by the operator. That is, the boom 4 can be raised. Also, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 175R via the proportional valve 31BR and the shuttle valve 32BR, regardless of the boom lowering operation by the operator. That is, the boom 4 can be lowered.

[0079] Also, as shown in FIG. 4C, the right operation lever 26R is also used to operate the bucket 6. Specifically, the right operation lever 26R uses the hydraulic oil discharged from the pilot pump 15 and applies a pilot pressure corresponding to the left-right direction operation 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), a pilot pressure corresponding to the operation amount is applied to the left pilot port of the control valve 174. Also, when the right operation lever 26R is operated in the bucket opening direction (right direction), a pilot pressure corresponding to the operation amount is applied to the right pilot port of the control valve 174.

[0080] 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.

[0081] The proportional valve 31CL operates in response to the current command output by the controller 30. Then, it adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31CL and the shuttle valve 32CL. The proportional valve 31CR operates in response to the current command output by the controller 30. Then, it adjusts the pilot pressure of the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31CR and the shuttle valve 32CR. The proportional valves 31CL and 31CR can adjust the pilot pressure so that the control valve 174 can be stopped at an arbitrary valve position.

[0082] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 174 via the proportional valve 31CL and the shuttle valve 32CL, regardless of the bucket closing operation by the operator. That is, the bucket 6 can be closed. Also, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 174 via the proportional valve 31CR and the shuttle valve 32CR, regardless of the bucket opening operation by the operator. That is, the bucket 6 can be opened.

[0083] Also, as shown in FIG. 4D, the left operation lever 26L is also used to operate the slewing mechanism 2. Specifically, the left operation lever 26L utilizes the hydraulic oil discharged from the pilot pump 15 and applies a pilot pressure corresponding to the left-right 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.

[0084] The operation pressure sensor 29LB detects the content of the left-right operation on the left operation lever 26L by the operator in the form of pressure and outputs the detected value to the controller 30.

[0085] The proportional valve 31DL operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure generated by the hydraulic oil introduced from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31DL and the shuttle valve 32DL. The proportional valve 31DR operates according to the current command output by the controller 30. Then, it adjusts the pilot pressure generated by the hydraulic oil introduced from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31DR and the shuttle valve 32DR. The proportional valves 31DL and 31DR can adjust the pilot pressure so that the control valve 173 can be stopped at an arbitrary valve position.

[0086] With this configuration, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the left pilot port of the control valve 173 via the proportional valve 31DL and the shuttle valve 32DL, regardless of the left turn operation by the operator. That is, the slewing mechanism 2 can be turned to the left. Also, the controller 30 can supply the hydraulic oil discharged from the pilot pump 15 to the right pilot port of the control valve 173 via the proportional valve 31DR and the shuttle valve 32DR, regardless of the right turn operation by the operator. That is, the slewing mechanism 2 can be turned to the right.

[0087] The excavator 100 may be configured to automatically move the lower traveling body 1 forward and backward. In this case, the hydraulic system part related to the operation of the left traveling hydraulic motor 2ML and the hydraulic system part related to the operation of the right traveling hydraulic motor 2MR may be configured in the same way as the hydraulic system part related to the operation of the boom cylinder 7 and the like.

[0088] In addition, although the description of the hydraulic operation system equipped with a hydraulic pilot circuit has been given as the form of the operation device 26, an electric operation system equipped with an electric pilot circuit may be adopted instead of the hydraulic operation system. In this case, the lever operation amount of the electric operation lever in the electric operation system is input to the controller 30 as an electric signal. Further, a solenoid valve is arranged between the pilot pump 15 and the pilot ports of the respective control valves. 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 the respective control valves. Note that each control valve may be configured 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.

[0089] Next, with reference to FIG. 5, the functions of the controller 30 will be described. FIG. 5 is a functional block diagram of the controller 30. In the example of FIG. 5, the controller 30 receives signals output from at least one of a posture detection device, an operation device 26, a space recognition device 70, an orientation detection device 71, an information input device 72, a positioning device 73, a switch NS, etc., executes various calculations, and can output control commands to at least one of a proportional valve 31, a display device D1, a sound output device D2, etc. The posture detection device includes 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 position calculation unit 30A, a trajectory acquisition unit 30B, an autonomous control unit 30C, and a control mode switching unit 30D as functional elements. Each functional element may be configured by hardware or may be configured by software.

[0090] The position calculation unit 30A is configured to calculate the position of the positioning target. In the present embodiment, the position calculation unit 30A calculates the coordinate points in the reference coordinate system of a predetermined part of the attachment. The predetermined part is, for example, the tip of the bucket 6. The origin of the reference coordinate system is, for example, the intersection of the slewing axis and the ground contact surface of the excavator 100. The position calculation unit 30A calculates, for example, the coordinate points of the tip of the bucket 6 from the respective rotation angles of the boom 4, the arm 5, and the bucket 6. The position calculation unit 30A may calculate not only the central coordinate point of the tip of the bucket 6, but also the left-end coordinate point and the right-end coordinate point of the tip of the bucket 6. In this case, the position calculation unit 30A may utilize the output of the machine body inclination sensor S4.

[0091] The trajectory acquisition unit 30B is configured to acquire a target trajectory, which is the trajectory followed by a predetermined part of the attachment when the excavator 100 operates autonomously. In the present embodiment, the trajectory acquisition unit 30B acquires the target trajectory to be used when the autonomous control unit 30C operates the excavator 100 autonomously. Specifically, the trajectory acquisition unit 30B derives the target trajectory based on the data regarding the target construction surface stored in the non-volatile memory device. The trajectory acquisition unit 30B may also derive the target trajectory based on the information regarding the terrain around the excavator 100 recognized by the space recognition device 70. Alternatively, the trajectory acquisition unit 30B may derive information regarding the past trajectory of the tip of the bucket 6 from the past outputs of the attitude detection device stored in the volatile memory device, and derive the target trajectory based on that information. Or, the trajectory acquisition unit 30B may derive the target trajectory based on the current position of the predetermined part of the attachment and the data regarding the target construction surface.

[0092] The autonomous control unit 30C is configured to operate the excavator 100 autonomously. In the present embodiment, when a predetermined start condition is satisfied, it is configured to move a predetermined part of the attachment along the target trajectory acquired by the trajectory acquisition unit 30B. Specifically, when the operating device 26 is operated while the switch NS is pressed, the excavator 100 is operated autonomously so that the predetermined part moves along the target trajectory.

[0093] In this embodiment, the autonomous control unit 30C is configured to assist the manual operation of the excavator by the operator by autonomously operating the actuator. For example, when the operator is manually performing an arm closing operation while pressing the switch NS, the autonomous control unit 30C may autonomously extend and contract at least one of the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 so that the target trajectory coincides with the position of the tip of the bucket 6. In this case, the operator can close the arm 5 while making the tip of the bucket 6 coincide with the target trajectory by, for example, only operating the left operation lever 26L in the arm closing direction. In this example, the arm cylinder 8, which is the main operation target, is referred to as the "main actuator". Further, the boom cylinder 7 and the bucket cylinder 9, which are passive operation targets that move according to the movement of the main actuator, are referred to as "subordinate actuators".

[0094] In this embodiment, the autonomous control unit 30C can autonomously operate each actuator by giving a current command to the proportional valve 31 and individually adjusting the pilot pressure acting on the control valve corresponding to each actuator. For example, at least one of the boom cylinder 7 and the bucket cylinder 9 can be operated regardless of whether the right operation lever 26R is tilted.

[0095] The control mode switching unit 30D is configured to be able to switch the control mode. The control mode is a control method of the actuator that can be used by the controller 30 when the autonomous control unit 30C autonomously operates the excavator 100, and includes, for example, a normal control mode and a low-speed control mode. The normal control mode is, for example, a control mode set so that the moving speed of a predetermined part with respect to the operation amount of the operation device 26 is relatively large, and the low-speed control mode is, for example, a control mode set so that the moving speed of a predetermined part with respect to the operation amount of the operation device 26 is relatively small. The control mode may include an arm priority mode and a boom priority mode.

[0096] Each control mode is used when the operating device 26 is operated with the switch NS pressed. For example, the arm priority mode is a control mode in which the arm cylinder 8 is selected as the main actuator and the boom cylinder 7 and the bucket cylinder 9 are selected as subordinate actuators. In the arm priority mode, for example, when the left operation lever 26L is operated in the arm closing direction, the controller 30 actively extends the arm cylinder 8 at a speed corresponding to the operation amount of the left operation lever 26L. Then, the controller 30 passively expands and contracts at least one of the boom cylinder 7 and the bucket cylinder 9 so that the tip of the bucket 6 moves along the target trajectory. The boom priority mode is a control mode in which the boom cylinder 7 is selected as the main actuator and the arm cylinder 8 and the bucket cylinder 9 are selected as subordinate actuators. In the boom priority mode, for example, when the left operation lever 26L is operated in the arm closing direction, the controller 30 actively expands and contracts the boom cylinder 7 at a speed corresponding to the operation amount of the left operation lever 26L. Then, the controller 30 passively extends the arm cylinder 8 so that the tip of the bucket 6 moves along the target trajectory, and passively expands and contracts the bucket cylinder 9 as necessary. Note that the control mode may include a bucket priority mode. The bucket priority mode is a control mode in which the bucket cylinder 9 is selected as the main actuator and the boom cylinder 7 and the arm cylinder 8 are selected as subordinate actuators. In the bucket priority mode, for example, when the left operation lever 26L is operated in the arm closing direction, the controller 30 actively expands and contracts the bucket cylinder 9 at a speed corresponding to the operation amount of the left operation lever 26L. Then, the controller 30 passively extends the arm cylinder 8 so that the tip of the bucket 6 moves along the target trajectory, and passively expands and contracts the boom cylinder 7 as necessary.

[0097] The control mode switching unit 30D may be configured to automatically switch the control mode when a predetermined condition is satisfied. The predetermined condition may be set based on, for example, the shape of the target trajectory, the presence or absence of buried objects, the presence or absence of objects around the excavator 100, and the like.

[0098] When the autonomous control is started, for example, the controller 30 first adopts the first control mode. The first control mode is, for example, the normal control mode. Then, when it is determined that a predetermined condition is satisfied during the execution of the autonomous control in which the first control mode is adopted, the control mode switching unit 30D switches the control mode from the first control mode to the second control mode. The second control mode is, for example, the low-speed control mode. In this case, the controller 30 terminates the autonomous control in which the first control mode is adopted and starts the autonomous control in which the second control mode is adopted. In this example, the controller 30 executes the autonomous control by selecting one of the two control modes, but it may also execute the autonomous control by selecting one of three or more control modes.

[0099] Next, with reference to FIG. 6, an example of a process in which the control mode switching unit 30D automatically switches the control mode (hereinafter referred to as "control mode switching process") will be described. FIG. 6 shows a cross section of the ground to be excavated. The dashed-dotted line in the figure represents the target trajectory TP. Also, the bucket 6A drawn in solid line represents the current position and posture of the bucket 6, and each of the buckets 6B to 6D drawn in dotted line represents the subsequent position and posture of the bucket 6.

[0100] In the example of FIG. 6, when the left operation lever 26L is operated in the arm closing direction with the switch NS pressed, the controller 30 executes the autonomous control using the normal control mode so that the tip of the claw of the bucket 6 moves along the target trajectory TP.

[0101] When the distance DS1 between the point P1 on the target trajectory TP and the tip of the bucket 6 is less than the predetermined distance TH1, the controller 30 determines that the predetermined condition is satisfied and switches the control mode from the normal control mode to the low-speed control mode. The point P1 is the boundary point between the trajectory portion TP1 and the trajectory portion TP2 that constitute the target trajectory TP. The angle α is the angle formed between the extension line of the trajectory portion TP1 and the trajectory portion TP2. The bucket 6B represents the position and orientation of the bucket 6 when the control mode is switched from the normal control mode to the low-speed control mode. Thus, when the angle formed between the two trajectory portions (two target construction surfaces) is greater than or equal to a predetermined angle, the controller 30 can decelerate the moving speed of the bucket 6 when the tip of the bucket 6 approaches the boundary point.

[0102] In this example, when the magnitude of the angle α is greater than or equal to the predetermined angle α TH the controller 30 determines that the predetermined condition is satisfied when the distance DS1 between the point P1 and the tip of the bucket 6 is less than the predetermined distance TH1. Note that the predetermined distance TH1 may be zero.

[0103] Also, after the tip of the bucket 6 passes the point P1, when the distance DS2 between the point P1 and the tip of the bucket 6 exceeds the predetermined distance TH2, the controller 30 determines that the predetermined condition is satisfied and switches the control mode from the low-speed control mode to the normal control mode. Note that when the predetermined distance TH1 is not zero, the predetermined distance TH2 may be zero. The bucket 6C represents the position and orientation of the bucket 6 when the control mode is switched from the low-speed control mode to the normal control mode.

[0104] With this configuration, the controller 30 can change the control mode from the normal control mode to the low-speed control mode when the tip of the bucket 6 passes through a portion where the traveling direction of the target trajectory TP changes significantly. Also, after the tip of the bucket 6 passes through a portion where the traveling direction of the target trajectory TP changes significantly, the controller 30 can return the control mode to the normal control mode. Therefore, the controller 30 can make the tip of the bucket 6 follow the target trajectory TP more accurately.

[0105] In the above example, the case where the bucket 6 moves from the track portion TP1 to the track portion TP2 is shown. However, even when the bucket 6 moves from the track portion TP2 to the track portion TP1, similarly, when the tip of the bucket 6 approaches the boundary point, the controller 30 may decelerate the moving speed of the bucket 6.

[0106] Next, referring to FIGS. 7A and 7B, another example of the control mode switching process will be described. FIGS. 7A and 7B both show cross-sections of the ground to be excavated. The dashed-dotted line in each of FIGS. 7A and 7B represents the target trajectory TP. Also, the bucket 6A drawn in solid line represents the current position and orientation of the bucket 6, and each of the buckets 6B to 6F drawn in dotted line represents the subsequent position and orientation of the bucket 6.

[0107] Specifically, FIG. 7A shows an example of changing the control mode based on the angle formed between a predetermined reference plane RP (for example, a horizontal plane, the grounding surface of the excavator 100, etc.) and the target trajectory TP, and FIG. 7B shows an example of changing the control mode based on the angle formed between two adjacent track portions.

[0108] In the example of FIG. 7A, when the left operation lever 26L is operated in the arm closing direction with the switch NS pressed, the controller 30 executes autonomous control using the arm priority mode so that the tip of the bucket 6 moves along the target trajectory TP.

[0109] Then, when the distance between the boundary point P11 on the target trajectory TP and the tip of the bucket 6 falls below a predetermined distance TH3, the controller 30 determines that a predetermined condition is satisfied and switches the control mode from the arm priority mode to the boom priority mode. The boundary point P11 is the boundary point between the track portion TP11 and the track portion TP12 that constitute the target trajectory TP. The angle β1 is the angle formed between the horizontal plane, which is the reference plane RP, and the track portion TP12. The bucket 6B represents the position and orientation of the bucket 6 when the control mode switches from the arm priority mode to the boom priority mode.

[0110] In this example, when the magnitude of the angle β1 is greater than or equal to the predetermined angle β TH TH

[0111] Also, after the tip of the bucket 6 passes the boundary point P11, when the distance between the boundary point P12 on the target trajectory TP and the tip of the bucket 6 is less than the predetermined distance TH4, the controller 30 determines that the predetermined condition is satisfied and switches the control mode from the boom priority mode to the arm priority mode. The boundary point P12 is the boundary point between the trajectory portion TP12 and the trajectory portion TP13 that make up the target trajectory TP. The bucket 6C represents the position and orientation of the bucket 6 when the control mode switches from the boom priority mode to the arm priority mode.

[0112] In this example, when the magnitude of the angle formed between the horizontal plane, which is the reference plane RP, and the trajectory portion TP13 is less than the predetermined angle β TH TH TH and the distance between the boundary point P12, which is the starting point of the trajectory portion TP13, and the tip of the bucket 6 is less than the predetermined distance TH4, the controller 30 determines that the predetermined condition is satisfied. And because the magnitude of the angle formed between the horizontal plane and the trajectory portion TP13 is less than the predetermined angle β, when the bucket 6 reaches the position shown by the bucket 6C, the controller 30 determines that the predetermined condition is satisfied and switches the control mode from the boom priority mode to the arm priority mode.

[0113] After the tip of the bucket 6 passes the boundary point P12 and the distance between the boundary point P13 on the target trajectory TP and the tip of the bucket 6 becomes less than the predetermined distance TH5, the controller 30 determines that the predetermined condition is satisfied and switches the control mode from the arm priority mode to the boom priority mode. The boundary point P13 is the boundary point between the trajectory portion TP13 and the trajectory portion TP14 that constitute the target trajectory TP. The angle β2 is the angle formed between the horizontal plane which is the reference plane RP and the trajectory portion TP14. The bucket 6D represents the position and orientation of the bucket 6 when the control mode switches from the arm priority mode to the boom priority mode.

[0114] In this example, when the magnitude of the angle β2 is greater than or equal to the predetermined angle β TH and the distance between the boundary point P13, which is the starting point of the trajectory portion TP14, and the tip of the bucket 6 becomes less than the predetermined distance TH5, the controller 30 determines that the predetermined condition is satisfied.

[0115] Also, after the tip of the bucket 6 passes the boundary point P13, when the distance between the boundary point P14 on the target trajectory TP and the tip of the bucket 6 becomes less than the predetermined distance TH6, the controller 30 determines that the predetermined condition is satisfied and switches the control mode from the boom priority mode to the arm priority mode. The boundary point P14 is the boundary point between the trajectory portion TP14 and the trajectory portion TP15 that constitute the target trajectory TP. The bucket 6E represents the position and orientation of the bucket 6 when the control mode switches from the boom priority mode to the arm priority mode.

[0116] In this example, when the magnitude of the angle formed between the horizontal plane which is the reference plane RP and the trajectory portion TP15 is less than the predetermined angle β TH and the distance between the boundary point P14, which is the starting point of the trajectory portion TP15, and the tip of the bucket 6 becomes less than the predetermined distance TH6, the controller 30 determines that the predetermined condition is satisfied. And when the magnitude of the angle formed between the horizontal plane and the trajectory portion TP15 is less than the predetermined angle β THSince it is less than, when the bucket 6 reaches the position shown by the bucket 6E, the controller 30 determines that a predetermined condition is satisfied, and switches the control mode from the boom priority mode to the arm priority mode.

[0117] Note that the predetermined distances TH3 to TH6 may be different values or the same value. Also, at least one of the predetermined distances TH3 to TH6 may be zero.

[0118] With this configuration, when the tip of the bucket 6 passes through the track portion with a steep gradient where the inclination angle with respect to the reference plane in the target track TP is greater than or equal to the predetermined angle β TH the boom priority mode can be adopted as the control mode. Also, when the tip of the bucket 6 passes through the track portion with a gentle gradient where the inclination angle is less than the predetermined angle β TH the arm priority mode can be adopted as the control mode. Therefore, the controller 30 can make the tip of the bucket 6 follow the target track TP more accurately. When the arm priority mode is adopted when the tip of the bucket 6 passes through the track portion with a steep gradient, there is a risk of moving the arm 5 too much. However, when the boom priority mode is adopted, excessive movement of the arm 5 can be prevented. Also, when the boom priority mode is adopted when the tip of the bucket 6 passes through the track portion with a gentle gradient, there is a risk of moving the boom 4 too much. However, when the arm priority mode is adopted, excessive movement of the boom 4 can be prevented.

[0119] Also, when the inclination angle with respect to the reference plane in the target track TP is greater than or equal to the predetermined angle β THWhen the tip of the bucket 6 passes near the boundary points (for example, boundary points P11 to P14) of the above steep gradient track portion, a low-speed control mode may be adopted as the control mode. Specifically, when the distance between the boundary point and the tip of the bucket 6 falls below a predetermined distance V, the controller 30 may determine that a predetermined condition is satisfied and switch the control mode to the low-speed control mode. In this case, the predetermined distance V may be set as a distance different from each of the predetermined distances TH3 to TH6, or may be set as the same distance as each of the predetermined distances TH3 to TH6. For example, the predetermined distance V may be a distance greater than each of the predetermined distances TH3 to TH6.

[0120] In the example of FIG. 7B, when the left operation lever 26L is operated in the arm closing direction with the switch NS pressed, the controller 30 executes autonomous control using the arm priority mode so that the tip of the bucket 6 moves along the target track TP.

[0121] In this example, when the magnitude of the angle γ1 formed between the extension line of the track portion TP11 and the track portion TP12 is a predetermined angle γ TH In the above case, when the distance between the boundary point P11 and the tip of the bucket 6 falls below a predetermined distance TH7, it is determined that a predetermined condition is satisfied. Then, the control mode is switched from the arm priority mode to the boom priority mode. The bucket 6B represents the position and orientation of the bucket 6 when the control mode is switched from the arm priority mode to the boom priority mode.

[0122] Also, when the magnitude of the angle γ2 formed between the extension line of the track portion TP12 and the track portion TP13 is a predetermined angle γ TH In the above case, when the distance between the boundary point P12 on the target track TP and the tip of the bucket 6 falls below a predetermined distance TH8, it is determined that a predetermined condition is satisfied. Then, the control mode is switched from the boom priority mode to the arm priority mode. The bucket 6C represents the position and orientation of the bucket 6 when the control mode is switched from the boom priority mode to the arm priority mode.

[0123] When the magnitude of the angle γ3 formed between the extension line of the track portion TP13 and the track portion TP14 is a predetermined angle γ TH or more, when the distance between the boundary point P13 on the target track TP and the tip of the bucket 6 is less than a predetermined distance TH9, it is determined that a predetermined condition is satisfied. Then, the control mode is switched from the arm priority mode to the boom priority mode. The bucket 6D represents the position and orientation of the bucket 6 when the control mode is switched from the arm priority mode to the boom priority mode.

[0124] When the magnitude of the angle γ4 formed between the extension line of the track portion TP14 and the track portion TP15 is a predetermined angle γ TH or more, when the distance between the boundary point P14 on the target track TP and the tip of the bucket 6 is less than a predetermined distance TH10, it is determined that a predetermined condition is satisfied. Then, the control mode is switched from the boom priority mode to the arm priority mode. The bucket 6E represents the position and orientation of the bucket 6 when the control mode is switched from the boom priority mode to the arm priority mode.

[0125] Note that the predetermined distances TH7 to TH10 may be different values or the same value. Also, at least one of the predetermined distances TH7 to TH10 may be zero.

[0126] With this configuration, the controller 30 can select a control mode suitable for the subsequent track portion when the traveling direction of the target track TP changes significantly. For example, one of the boom priority mode and the arm priority mode can be switched to the other. Therefore, the controller 30 can make the tip of the bucket 6 follow the target track TP more accurately.

[0127] In addition, when the magnitude of the angle formed between two adjacent track portions is a predetermined angle γ THWhen the tip of the bucket 6 passes near the boundary points (for example, boundary points P11 to P14) of the above two orbital portions, a low-speed control mode may be adopted as the control mode. Specifically, when the distance between the boundary point and the tip of the bucket 6 is less than a predetermined distance W, the controller 30 may determine that a predetermined condition is satisfied and switch the control mode to the low-speed control mode. In this case, the predetermined distance W may be set as a distance different from each of the predetermined distances TH7 to TH10, or may be set as the same distance as each of the predetermined distances TH7 to TH10. For example, the predetermined distance W may be a distance greater than each of the predetermined distances TH7 to TH10.

[0128] Next, with reference to FIG. 8, another example of the control mode switching process will be described. FIG. 8 shows a cross-section of the ground to be excavated. The dashed line in the figure represents the target trajectory TP. The bucket 6A drawn in solid line represents the current position and attitude of the bucket 6, and each of the buckets 6B to 6D drawn in dotted line represents the subsequent position and attitude of the bucket 6. The striped pattern represents the cross-section of the buried object BM such as a water pipe.

[0129] In the example of FIG. 8, when the left operation lever 26L is operated in the arm closing direction with the switch NS pressed, the controller 30 executes autonomous control using the normal control mode so that the tip of the bucket 6 moves along the target trajectory TP.

[0130] When the distance between the point P21 on the target trajectory TP and the tip of the bucket 6 is less than a predetermined distance TH11, the controller 30 determines that a predetermined condition is satisfied and switches the control mode from the normal control mode to the low-speed control mode. The point P21 is a boundary point between the trajectory portion TP21 and the trajectory portion TP22 that constitute the target trajectory TP. The trajectory portion TP22 is a trajectory portion set near the buried object BM. In this example, the trajectory portion TP22 is a set of points on the target trajectory TP where the distance from the buried object BM is less than a predetermined distance X. Therefore, the distance between the point P21 and the buried object BM1 is equal to the predetermined distance X. The bucket 6B represents the position and orientation of the bucket 6 when the control mode is switched from the normal control mode to the low-speed control mode.

[0131] Further, when the distance between the point P22 on the target trajectory TP and the tip of the bucket 6 is less than a predetermined distance TH12, the controller 30 determines that a predetermined condition is satisfied and switches the control mode from the low-speed control mode to the normal control mode. The point P22 is a boundary point between the trajectory portion TP22 and the trajectory portion TP23 that constitute the target trajectory TP. The distance between the point P22 and the buried object BM2 is equal to the predetermined distance X. The bucket 6C represents the position and orientation of the bucket 6 when the control mode is switched from the low-speed control mode to the normal control mode.

[0132] Note that the predetermined distances TH11 and TH12 may be different values or the same value. Further, at least one of the predetermined distances TH11 and TH12 may be zero.

[0133] With this configuration, the controller 30 can change the control mode from the normal control mode to the low-speed control mode when the tip of the bucket 6 passes near the buried object BM. Also, the controller 30 can return the control mode to the normal control mode when the tip of the bucket 6 moves away from the buried object BM. Therefore, when the controller 30 moves the tip of the bucket 6 along the target trajectory TP, it can accurately control the tip of the bucket 6 at a low speed and prevent the buried object from being severely damaged by the tip of the bucket 6.

[0134] Next, referring to FIGS. 9A and 9B, another example of the control mode switching process will be described. FIGS. 9A and 9B are both top views of the ground to be excavated and the excavator 100. The dashed-dotted line in each of FIGS. 9A and 9B represents the target trajectory TP. The target trajectory TP is set to become deeper step by step between the current ground surface and the target construction surface so that, for example, the target construction surface is formed by a plurality of excavation operations. Also, the bucket 6A drawn in solid line represents the current position and posture of the bucket 6, and the bucket 6B drawn in dotted line represents the subsequent position and posture of the bucket 6. The finely shaded area represents the portion R1 (relatively deep portion) where the vertical distance between the currently set target trajectory TP and the target construction surface is relatively small, and the coarsely shaded area represents the portion R2 (relatively shallow portion) where the vertical distance between the currently set target trajectory TP and the target construction surface is relatively large.

[0135] In the example of FIG. 9A, when the left operation lever 26L is operated in the arm closing direction with the switch NS pressed, the controller 30 executes semi-automatic control so that the tip of the bucket 6 moves along the target trajectory TP31.

[0136] And when it is determined that the vertical distance between the target trajectory TP31 and the target construction surface falls below a predetermined distance Y, the controller 30 determines that a predetermined condition is satisfied and switches the control mode from the normal control mode to the low-speed control mode. The bucket 6A represents the position and posture of the bucket 6 when the control mode switches from the normal control mode to the low-speed control mode. The bucket 6B represents the position and posture of the bucket 6 when the tip of the bucket 6 reaches the end of the target trajectory TP.

[0137] In the example of FIG. 9B, the controller 30, as in the case of FIG. 9A, when the left operation lever 26L is operated in the arm closing direction with the switch NS pressed, performs semi-automatic control so that the tip of the bucket 6 moves along the target trajectory TP32. The operator of the excavator 100, for example, performs a left turning operation immediately after the excavation operation shown in FIG. 9A is completed to bring the direction of the excavation attachment AT to the state shown in FIG. 9B. Then, the operator starts the excavation operation shown in FIG. 9B. Therefore, the excavation operation shown in FIG. 9A and the excavation operation shown in FIG. 9B can be recognized as a series of excavation operations.

[0138] In the excavation operation shown in FIG. 9B, the controller 30 first determines whether the vertical distance between the target trajectory TP32 and the target construction surface is less than a predetermined distance Y. And when it is determined that the distance does not fall below the predetermined distance Y, it is determined that the predetermined condition is not satisfied. Therefore, the controller 30 performs semi-automatic control using the normal control mode as it is without switching the control mode from the normal control mode to the low-speed control mode.

[0139] In this way, when semi-automatic control is performed for the excavation of the portion R1, the controller 30 automatically selects the low-speed control mode, and when semi-automatic control is performed for the excavation of the portion R2, the controller 30 automatically selects the normal control mode. That is, the controller 30 automatically selects an appropriate control mode according to the state of the excavation target such as the vertical distance between the target construction surface and the target trajectory TP without forcing the operator of the excavator 100 to perform an operation to switch the control mode. Specifically, the finish mode (low-speed control mode) is selected for the portion R1, and the normal control mode is selected for the portion R2. Therefore, the working efficiency of the excavator 100 can be improved.

[0140] Next, referring to FIG. 10, the details of the semi-automatic control by the controller 30 will be described. FIG. 10 is a block diagram showing an example of the relationship between functional elements F1 to F6 related to the execution of semi-automatic control in the controller 30.

[0141] As shown in FIG. 10, the controller 30 has functional elements F1 to F6 related to the execution of semi-automatic control. The functional elements may be configured by software, may be configured by hardware, or may be configured by a combination of software and hardware.

[0142] The functional element F1 is configured to analyze an operation tendency, which is a tendency of manual operation by an operator. In the present embodiment, the functional element F1 analyzes the operation tendency based on the operation data output by the operation pressure sensor 29, and outputs the analysis result together with the operation data. The operation tendency is, for example, a tendency to move the tip of the bucket 6 linearly closer to the machine body, a tendency to move the tip of the bucket 6 linearly away from the machine body, a tendency to linearly raise the tip of the bucket 6, and a tendency to linearly lower the tip of the bucket 6. Then, the functional element F1 outputs, as an analysis result, which operation tendency the current operation tendency matches.

[0143] The functional element F2 is configured to generate a target trajectory. In the present embodiment, the functional element F2 corresponds to the trajectory acquisition unit 30B shown in FIG. 5. Specifically, the functional element F2 refers to the design data stored in the storage device 47 mounted on the excavator 100, and generates a trajectory that the tip of the bucket 6 should follow during excavation work or the like.

[0144] The storage device 47 is configured to store various information. The storage device 47 is, for example, a non-volatile storage medium such as a semiconductor memory. The storage device 47 may store information output by various devices during the operation of the excavator 100, or may store information acquired through various devices before the operation of the excavator 100 is started. The storage device 47 may store, for example, data related to a target construction surface acquired through a communication device or the like. The target construction surface may be set by the operator of the excavator 100, or may be set by a construction manager or the like.

[0145] The functional element F3 is configured to calculate the current bucket tip position. In the present embodiment, the functional element F3 corresponds to the position calculation unit 30A shown in FIG. 5. Specifically, the functional element F3 calculates the coordinate point of the bucket tip of the bucket 6 as the current bucket tip position based on the boom angle θ1 detected by the boom angle sensor S1, the arm angle θ2 detected by the arm angle sensor S2, and the bucket angle θ3 detected by the bucket angle sensor S3. The functional element F3 may utilize the output of the body inclination sensor S4 when calculating the current bucket tip position.

[0146] The functional element F4 is configured to calculate the next bucket tip position. In the present embodiment, the functional element F4 calculates the bucket tip position after a predetermined time as the target bucket tip position based on the operation data output by the functional element F1 and the analysis result of the operation tendency, the target trajectory generated by the functional element F2, and the current bucket tip position calculated by the functional element F3.

[0147] The functional element F5 is configured to switch the control mode. In the present embodiment, the functional element F5 corresponds to the control mode switching unit 30D shown in FIG. 5. Specifically, the functional element F5 refers to the control mode data stored in the storage device 47 and selects either the normal fresh fish mode or the low-speed control mode as the control mode.

[0148] The functional element F6 is configured to calculate a command value for operating the actuator. In the present embodiment, when the normal control mode is selected, the functional element F6 calculates at least one of the boom command value θ1 * , the arm command value θ2 * , and the bucket command value θ3 * based on the target bucket tip position calculated by the functional element F4 in order to move the current bucket tip position to the target bucket tip position at a relatively high moving speed.

[0149] Also, when the low-speed control mode is selected, the functional element F6 calculates at least one of the boom command value θ1 *, the boom command value θ2 * , and the bucket command value θ3 * Calculate at least one of them.

[0150] Next, referring to FIG. 11, the details of the functional element F6 will be described. FIG. 11 is a block diagram showing a configuration example of the functional element F6 that calculates various command values.

[0151] As shown in FIG. 11, the controller 30 further has functional elements F11 to F13, F21 to F23, and F31 to F33 related to the generation of command values. The functional elements may be configured by software, may be configured by hardware, or may be configured by a combination of software and hardware.

[0152] The functional elements F11 to F13 are functional elements related to the boom command value θ1 * , the functional elements F21 to F23 are functional elements related to the arm command value θ2 * , and the functional elements F31 to F33 are functional elements related to the bucket command value θ3 * .

[0153] The functional elements F11, F21, and F31 are configured to generate current commands output to the proportional valves 31. In this embodiment, the functional element F11 outputs a boom current command to the boom proportional valve 31B (see the proportional valves 31BL and 31BR in FIG. 4B), the functional element F21 outputs an arm current command to the arm proportional valve 31A (see the proportional valves 31AL and 31AR in FIG. 4A), and the functional element F31 outputs a bucket current command to the bucket proportional valve 31C (see the proportional valves 31CL and 31CR in FIG. 4C).

[0154] The functional elements F12, F22, and F32 are configured to calculate the displacement amount of the spool that constitutes the spool valve. In the present embodiment, the functional element F12 calculates the displacement amount of the boom spool that constitutes the control valve 175 related to the boom cylinder 7 based on the output of the boom spool displacement sensor S11. The functional element F22 calculates the displacement amount of the arm spool that constitutes the control valve 176 related to the arm cylinder 8 based on the output of the arm spool displacement sensor S12. The functional element F23 calculates the displacement amount of the bucket spool that constitutes the control valve 174 related to the bucket cylinder 9 based on the output of the bucket spool displacement sensor S13.

[0155] The functional elements F13, F23, and F33 are configured to calculate the rotation angle of the working body. In the present embodiment, the functional element F13 calculates the boom angle θ1 based on the output of the boom angle sensor S1. The functional element F23 calculates the arm angle θ2 based on the output of the arm angle sensor S2. The functional element F33 calculates the bucket angle θ3 based on the output of the bucket angle sensor S3.

[0156] Specifically, the functional element F11 basically generates a boom current command for the boom proportional valve 31B such that the difference between the boom command value θ1 generated by the functional element F6 * and the boom angle θ1 calculated by the functional element F13 becomes zero. At that time, the functional element F11 adjusts the boom current command such that the difference between the target boom spool displacement amount derived from the boom current command and the boom spool displacement amount calculated by the functional element F12 becomes zero. Then, the functional element F11 outputs the adjusted boom current command to the boom proportional valve 31B.

[0157] The boom proportional valve 31B changes the opening area according to the boom current command, and applies a pilot pressure corresponding to the magnitude of the boom command current to the pilot port of the control valve 175. The control valve 175 moves the boom spool according to the pilot pressure, and causes the hydraulic oil to flow into the boom cylinder 7. The boom spool displacement sensor S11 detects the displacement of the boom spool, and feeds back the detection result to the functional element F12 of the controller 30. The boom cylinder 7 expands and contracts according to the inflow of the hydraulic oil, and moves the boom 4 up and down. The boom angle sensor S1 detects the rotation angle of the boom 4 that moves up and down, and feeds back the detection result to the functional element F13 of the controller 30. The functional element F13 feeds back the calculated boom angle θ1 to the functional element F3.

[0158] The functional element F21 basically generates an arm current command for the arm proportional valve 31A so that the difference between the arm command value θ2 generated by the functional element F6 * and the arm angle θ2 calculated by the functional element F23 becomes zero. At that time, the functional element F21 adjusts the arm current command so that the difference between the target arm spool displacement amount derived from the arm current command and the arm spool displacement amount calculated by the functional element F22 becomes zero. Then, the functional element F21 outputs the adjusted arm current command to the arm proportional valve 31A.

[0159] The arm proportional valve 31A changes the opening area according to the arm current command, and applies a pilot pressure corresponding to the magnitude of the arm command current to the pilot port of the control valve 176. The control valve 176 moves the arm spool according to the pilot pressure, and causes the hydraulic oil to flow into the arm cylinder 8. The arm spool displacement sensor S12 detects the displacement of the arm spool, and feeds back the detection result to the functional element F22 of the controller 30. The arm cylinder 8 expands and contracts according to the inflow of the hydraulic oil, and opens and closes the arm 5. The arm angle sensor S2 detects the rotation angle of the arm 5 that opens and closes, and feeds back the detection result to the functional element F23 of the controller 30. The functional element F23 feeds back the calculated arm angle θ2 to the functional element F3.

[0160] Similarly, the functional element F31 basically generates a bucket current command for the bucket proportional valve 31C such that the difference between the bucket command value θ3 generated by the functional element F6 and the bucket angle θ3 calculated by the functional element F33 becomes zero. At this time, the functional element F31 adjusts the bucket current command such that the difference between the target bucket spool displacement amount derived from the bucket current command and the bucket spool displacement amount calculated by the functional element F32 becomes zero. Then, the functional element F31 outputs the adjusted bucket current command to the bucket proportional valve 31C. * The bucket proportional valve 31C changes the opening area according to the bucket current command and applies a pilot pressure corresponding to the magnitude of the bucket command current to the pilot port of the control valve 174. The control valve 174 moves the bucket spool according to the pilot pressure and allows the working oil to flow into the bucket cylinder 9. The bucket spool displacement sensor S13 detects the displacement of the bucket spool and feeds back the detection result to the functional element F32 of the controller 30. The bucket cylinder 9 expands and contracts according to the inflow of the working oil and opens and closes the bucket 6. The bucket angle sensor S3 detects the rotation angle of the opening and closing bucket 6 and feeds back the detection result to the functional element F33 of the controller 30. The functional element F33 feeds back the calculated bucket angle θ3 to the functional element F3.

[0161] As described above, the controller 30 constitutes a three-stage feedback loop for each working body. That is, the controller 30 constitutes a feedback loop regarding the spool displacement amount, a feedback loop regarding the rotation angle of the working body, and a feedback loop regarding the tip position of the claw. Therefore, the controller 30 can precisely control the movement of the tip of the bucket 6 during semi-automatic control.

[0162]

[0163] ​As described above, the excavator 100 according to claim 1 of the present application includes a lower traveling body 1, an upper swing body 3 rotatably mounted on the lower traveling body 1, an attachment provided on the upper swing body 3, a plurality of actuators for operating the attachment, an operating device 26 provided on the upper swing body 3, and a controller 30 as a control device configured to operate the plurality of actuators according to an operation of the operating device 26 in a first direction to move a predetermined portion of the attachment based on position information. The position information is, for example, at least one of information regarding the position of a target construction surface and information regarding the position of the tip of the bucket 6. The controller 30 is configured to operate the plurality of actuators in a first control mode and a second control mode based on the position information, for example. Typically, the controller 30 is configured to operate the plurality of actuators in a first control mode and a second control mode along a target trajectory TP as a predetermined trajectory derived from the position information.

[0164] Specifically, the plurality of actuators may be, for example, a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 for operating an excavation attachment AT. In this case, the controller 30 may operate the plurality of actuators according to an operation of a left operation lever 26L, which is an example of the operating device 26, in the arm closing direction to move the tip of the bucket 6, which is a predetermined portion of the excavation attachment AT, along the target trajectory TP. The target trajectory TP may include, for example, a trajectory portion TP11 as a first trajectory portion for operating the plurality of actuators in an arm priority mode as the first control mode and a trajectory portion TP12 as a second trajectory portion for operating the plurality of actuators in a boom priority mode as the second control mode, as shown in FIG. 7A.

[0165] With this configuration, the excavator 100 can more appropriately control the movement of a predetermined portion of the attachment along a predetermined trajectory.

[0166] Further, as shown in FIG. 6, the first control mode may be a normal control mode. In this case, the second control mode may be a low-speed control mode. That is, the moving speed of a predetermined part with respect to the operation amount of the operating device 26 in the first control mode may be set to be greater than the moving speed of the predetermined part with respect to the operation amount of the operating device 26 in the second control mode.

[0167] With this configuration, the excavator 100 can change the control mode from the normal control mode to the low-speed control mode, for example, when the tip of the bucket 6 passes through an orbital portion where the traveling direction of the target orbit TP changes significantly. Further, after the tip of the bucket 6 has passed through a portion where the traveling direction of the target orbit TP changes significantly, the controller 30 can return the control mode to the normal control mode. Therefore, the controller 30 can make the tip of the bucket 6 more accurately follow the target orbit TP.

[0168] Further, as shown in FIG. 7A, when the angle of the target orbit TP with respect to the reference plane is less than a predetermined angle β TH the controller 30 may operate a plurality of actuators in an arm priority mode as the first control mode, and when the angle of the target orbit TP with respect to the reference plane is greater than or equal to the predetermined angle β TH the controller 30 may operate a plurality of actuators in an arm priority mode as the second control mode.

[0169] With this configuration, the controller 30 can adopt a boom priority mode as the control mode when the tip of the bucket 6 passes through an orbit portion with a gentle slope where the inclination angle with respect to the reference plane of the target orbit TP is less than the predetermined angle β TH and can adopt an arm priority mode as the control mode when the tip of the bucket 6 passes through an orbit portion with a steep slope where the inclination angle is greater than or equal to the predetermined angle β TH Therefore, the controller 30 can make the tip of the bucket 6 more accurately follow the target orbit TP.

[0170] Further, as shown in FIG. 8, when the embedded object BM is not near the tip of the bucket 6, the controller 30 may operate a plurality of actuators in the normal control mode, and when the embedded object BM is near the tip of the bucket 6, the controller 30 may operate the plurality of actuators in the low-speed control mode.

[0171] With this configuration, when the tip of the bucket 6 passes near the embedded object BM, the controller 30 can change the control mode from the normal control mode to the low-speed control mode. Further, when the tip of the bucket 6 moves away from the embedded object BM, the controller 30 can return the control mode to the normal control mode. Therefore, when the controller 30 moves the tip of the bucket 6 along the target trajectory TP, it can prevent the embedded object from being severely damaged by the tip of the bucket 6.

[0172] Further, when the controller 30 recognizes an object around the excavator based on the output of the space recognition device 70 provided on the upper swing body 3, the controller 30 may operate a plurality of actuators in the low-speed control mode as the second control mode.

[0173] With this configuration, when an object such as an operator exists around the excavator 100, the controller 30 can change the control mode from the normal control mode to the low-speed control mode. Therefore, when the controller 30 moves the tip of the bucket 6 along the target trajectory TP, it can prevent a part of the excavator 100 from coming into contact with the object. This is because by slowing down the movement of the excavation attachment AT, the attention of the operator of the excavator 100 can be drawn, and also because time can be given to the operator to determine whether an operation is required to avoid contact between a part of the excavator 100 and the object.

[0174] Further, when the target trajectory TP is within a predetermined distance range from the excavator 100 and the angle with respect to the reference plane of the target trajectory TP is within a predetermined angle range, the controller 30 may operate the plurality of actuators in the first control mode, and in other cases, may operate the plurality of actuators in the second control mode. In this case, the first control mode may be one of the arm priority mode and the boom priority mode, and the second control mode may be the other of the arm priority mode and the boom priority mode. Whether the bucket 6 is within a predetermined distance range from the excavator 100 in the target trajectory TP is determined based on, for example, the detection value of the attitude detection device.

[0175] Further, the controller 30 may detect the attitude of the attachment based on the detection value from the attitude detection device, and further determine whether to operate the plurality of actuators in the first control mode or the second control mode based on the attitude of the attachment. For example, when the controller 30 determines that the attitude of the attachment is a predetermined attitude, the plurality of actuators may be operated in the first control mode, and in other cases, may be operated in the second control mode.

[0176] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments. Various modifications, 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 there is no technical contradiction.

[0177] For example, in the above-described embodiment, a hydraulic operation system including a hydraulic pilot circuit is adopted, but an electric operation system including an electric pilot circuit may be adopted. When the electric operation system is adopted, the controller 30 can easily switch between the manual control mode and the semi-automatic control mode. And when the controller 30 switches from the manual control mode to the semi-automatic control mode, the plurality of control valves may be separately controlled according to an electric signal corresponding to the lever operation amount of one electric operation lever.

[0178] FIG. 12 shows a configuration example of an electric operation system. Specifically, the electric operation system in FIG. 12 is an example of a boom operation system, and mainly includes a pilot pressure actuated control valve 17, a boom operation lever 26A as an electric operation lever, a controller 30, a solenoid valve 60 for boom raising operation, and a solenoid valve 62 for boom lowering operation. The electric operation system in FIG. 12 can be similarly applied to an arm operation system, a bucket operation system, etc.

[0179] The pilot pressure actuated control valve 17 includes a control valve 175 (see FIG. 3) for the boom cylinder 7, a control valve 176 (see FIG. 3) for the arm cylinder 8, a control valve 174 (see FIG. 3) for the bucket cylinder 9, etc. The solenoid valve 60 is configured to be able to adjust the flow passage area of a pipeline connecting the pilot pump 15 and the raising side pilot port of the control valve 175. The solenoid valve 62 is configured to be able to adjust the flow passage area of a pipeline connecting the pilot pump 15 and the lowering side pilot port of the control valve 175.

[0180] When manual operation is performed in the manual control mode, the controller 30 generates a boom raising operation signal (electrical signal) or a boom lowering operation signal (electrical signal) according to an operation signal (electrical signal) output by the operation signal generation unit of the boom operation lever 26A. The operation signal output by the operation signal generation unit of the boom operation lever 26A is an electrical signal that changes according to the operation amount and operation direction of the boom operation lever 26A.

[0181] Specifically, when the boom operation lever 26A 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 60. The solenoid valve 60 adjusts the flow passage area according to the boom raising operation signal (electrical signal) and controls the pilot pressure acting on the raising side pilot port of the control valve 175. Similarly, when the boom operation lever 26A 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 62. The solenoid valve 62 adjusts the flow passage area according to the boom lowering operation signal (electrical signal) and controls the pilot pressure acting on the lowering side pilot port of the control valve 175.

[0182] When performing semi-automatic control in the semi-automatic control mode, the controller 30 generates a boom raising operation signal (electrical signal) or a boom lowering operation signal (electrical signal) according to a correction operation signal (electrical signal), for example, instead of the operation signal output by the operation signal generation unit of the boom operation lever 26A. The correction operation signal may be an electrical signal generated by the controller 30 or an electrical signal generated by an external control device other than the controller 30.

[0183] This application claims priority based on Japanese Patent Application No. 2018-068048 filed on March 30, 2018, and the entire contents of this Japanese patent application are incorporated herein by reference.

Explanation of Reference Numerals

[0184] 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 18 ··· Throttle 19 ··· Control pressure sensor 26 ··· Operating device 26A ··· Boom operation lever 26D ··· Traveling lever 26DL ··· Left traveling lever 26DR ··· Right traveling 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 ··· Position calculation unit 30B ··· Orbit acquisition unit 30C ··· Autonomous control unit 30D ··· Control mode switching unit 31, 31AL~31DL, 31AR~31DR ··· Proportional valve 31A ··· Arm proportional valve 31B ··· Boom proportional valve 31C ··· Bucket proportional valve 32, 32AL~32DL, 32AR~32DR ··· Shuttle valve 40 ··· Center bypass pipeline 42 ··· Parallel pipeline 47 ··· Memory device 60, 62 ··· Solenoid valve 70 ··· Space recognition device 70F ··· Front sensor 70B ··· Rear sensor 70L ··· Left sensor 70R ··· Right sensor 71 ··· Direction detection device 72 ··· Information input device 73 ··· Positioning device 100 ··· Excavator 171~176 ··· Control valve AT ··· Excavation attachment D1 ··· Display device D2 ··· Sound output device F1~F6, F11~F13, F21~F23, F31~F33 ··· Functional elements NS ··· Switch S1 ··· Boom angle sensor S2 ··· Arm angle sensor S3 ··· Bucket angle sensor S4 ··· Machine body inclination sensor S5 ··· Slewing angular velocity sensor S11 ··· Boom spool displacement sensor S12 ··· Arm spool displacement sensor S13 ··· Bucket spool displacement sensor

Claims

1. A lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, an attachment provided on the upper slewing body, a plurality of actuators for operating the attachment, an operating device provided on the upper slewing body, and a control device configured to operate the plurality of actuators in response to an operation of the operating device in a first direction to move a predetermined part of the attachment based on position information. When moving the predetermined part while matching it with a predetermined orbit, the control device operates the plurality of actuators in a first control mode and a second control mode based on the position information. An excavator.

2. The moving speed of the predetermined part with respect to the operation amount of the operating device in the first control mode is greater than the moving speed of the predetermined part with respect to the operation amount of the operating device in the second control mode. The excavator according to Claim 1.

3. When the angle of the orbit with respect to the reference plane is less than a predetermined angle, the control device operates the plurality of actuators in the first control mode, and when the angle of the orbit with respect to the reference plane is equal to or greater than the predetermined angle, the control device operates the plurality of actuators in the second control mode. The excavator according to Claim 1.

4. When no buried object exists near the predetermined part, the control device operates the plurality of actuators in the first control mode, and when a buried object exists near the predetermined part, the control device operates the plurality of actuators in the second control mode. The excavator according to Claim 1.

5. In an orbit portion including a point where the direction of the orbit changes by a predetermined angle or more, the control device operates the plurality of actuators in the second control mode. The excavator according to Claim 1.

6. When the control device recognizes an object around the excavator based on the output of a space recognition device provided on the upper slewing body, the control device operates the plurality of actuators in the second control mode. The excavator according to Claim 1.

7. When the orbit is within a predetermined distance range from the excavator and the angle of the orbit with respect to the reference plane is within a predetermined angle range, the control device operates the plurality of actuators in the first control mode, and in other cases, the control device operates the plurality of actuators in the second control mode. The excavator according to Claim 1.

8. comprising a posture detection device for detecting the posture of the attachment, the control device detects the posture of the attachment based on the detection value from the posture detection device, and further determines whether to operate the plurality of actuators in the first control mode or the second control mode based on the posture of the attachment. The excavator according to claim 3.

9. The control device switches between the first control mode and the second control mode according to the portion of the excavation target. The excavator according to claim 1.

10. The trajectory is a target trajectory set before the predetermined portion follows it. The control device switches between the first control mode and the second control mode according to the change in the position information along the target trajectory. The excavator according to claim 1.

11. a lower traveling body, an upper slewing body rotatably mounted on the lower traveling body, an attachment including a boom and an arm provided on the upper slewing body, a plurality of actuators for operating the attachment, an operating device provided on the upper slewing body, and a control device configured to operate a plurality of the actuators in response to an operation of the operating device in a first direction to move a predetermined portion of the attachment along a predetermined trajectory set on the ground to be excavated based on position information. The plurality of actuators include a boom cylinder for moving the boom and an arm cylinder for moving the arm. The control device operates the arm to be subordinate to the boom. Excavator.

12. The trajectory is a target trajectory set before the predetermined portion follows it. The control device operates the arm to be subordinate to the boom along the target trajectory. The excavator according to claim 11.

13. The control device switches between an operation in which the arm is subordinate to the boom and an operation in which the boom is subordinate to the arm. The excavator according to claim 11.

Images