Shovel and shovel control device

Abstract

The invention provides a shovel and a control device of the shovel. The control device of the shovel can restrain buried objects from being damaged during digging work. A controller (30), which is a control device for a shovel (100) having a detection device for detecting information relating to a ground surface that swells due to excavation, estimates the presence or absence of an embedded object such as a water pipe (U1) on the basis of at least one of an excavation reaction force calculated when excavation is performed by an excavation attachment device (AT) of the shovel (100) and the information detected by the detection device. When it is estimated that there is an embedded object, the controller (30) can control the operation of the excavation attachment (AT) so as to be able to avoid contact between the embedded object and the excavation attachment (AT).

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-218208 filed on December 25, 2023. The entire content of the Japanese application is incorporated herein by reference. Technical Field

[0002] The present invention relates to an excavator and a control device for an excavator. Background Art

[0003] Conventionally, an excavator (see Patent Document 1) known as an earth-moving machine for excavating the ground has been known. This excavator is configured to be able to move an excavation attachment mounted on an upper swing body to excavate sand and soil.

[0004] Patent Document 1: International Publication No. 2015 / 194601

[0005] However, if excavation work is carried out by an excavator at a construction site where buried objects such as water pipes are buried underground, there is a possibility of accidentally damaging the buried objects. Summary of the Invention

[0006] In view of the above, it is desirable to provide a control device for an excavator that can suppress damage to buried objects during excavation work.

[0007] In the control device for an excavator according to an embodiment of the present invention, the excavator has a detection device that detects information related to the ground that bulges due to excavation, and the control device of the excavator infers the presence or absence of a buried object based on at least one of the excavation reaction force calculated during excavation by the excavation attachment of the excavator and the information detected by the detection device.

[0008] Advantages of the Invention

[0009] By the above method, a control device for an excavator that can suppress damage to buried objects during excavation work is provided. Brief Description of the Drawings

[0010] Figure 1 It is a side view of an excavator according to an embodiment of the present invention.

[0011] Figure 2 It shows Figure 1 a side view of an excavator showing the relationship between the excavation attachment of the excavator and various physical quantities.

[0012] Figure 3 It is a diagram showing Figure 1 an example of the structure of a basic system of an excavator mounted on

[0013] Figure 4 It is a diagram showing Figure 1A diagram of the structure example of the excavation control system of an excavator.

[0014] Figure 5 A diagram showing a cross-section of a foundation in which a water pipe is buried.

[0015] Figure 6 A graph showing the relationship between the excavation reaction force and the approach distance.

[0016] Figure 7 A diagram showing an example of the output image displayed on the image display unit.

[0017] Figure 8 A diagram showing another structural example of the excavation control system.

[0018] Figure 9 A diagram showing a cross-section of a foundation in which a water pipe is buried.

[0019] Figure 10 A top view of an excavation attachment that performs an excavation operation.

[0020] Figure 11 A schematic diagram showing a structural example of the control system of an excavator.

[0021] In the figure: 1 - Lower traveling body, 1A - Left traveling hydraulic motor, 1B - Right traveling hydraulic motor, 2 - Swing mechanism, 2A - Swing hydraulic motor, 3 - Upper swing body, 4 - Boom, 5 - Arm, 6 - Bucket, 7 - Boom cylinder, 8 - Arm cylinder, 9 - Bucket cylinder, 10 - Cab, 11 - Engine, 11a - Alternator, 11b - Starter, 11c - Water temperature sensor, 14 - Main pump, 14a - Regulator, 14b - Discharge pressure sensor, 14c - Oil temperature sensor, 15 - Pilot pump, 15a, 15b - Pilot pressure sensors, 16 - Working oil pipeline, 17 - Control valve unit, 25, 25a - Pilot pipelines, 26 - Operating device, 26A, 26B - Levers, 26C - Pedal, 30 - Controller, 30a - Temporary storage section, 31 - Excavation reaction force calculation section, 32 - Buried object detection section, 40 - Display device, 41 - Image display unit, 42 - Input section, 45 - Sound output device, 70 - Object detection device, 72 - Electrical fittings, 74 - Engine control device, 75 - Operating mode changeover switch, 76 - Buried object detection mode switch, 90 - Battery, 100 - Excavator, 200 - Support device, 300 - Management device, E1 - Control valve, M1 - Posture detection device, M1a - Boom angle sensor, M1b - Arm angle sensor, M1c - Bucket angle sensor, S1, S11~S18 - Excavation pressure sensors, SYS - Control system, U1 - Water pipe. Detailed implementation mode

[0022] First, refer to Figure 1 An excavator (excavator 100) as a construction machine according to an embodiment of the present invention will be described. Figure 1 FIG. 4 is a side view of the excavator 100 according to the embodiment of the present invention. In Figure 1 In the lower traveling body 1 of the excavator 100 shown, an upper slewing body 3 is rotatably mounted via a slewing mechanism 2. Further, a boom 4 is mounted on the upper slewing body 3, an arm 5 is mounted at the end of the boom 4, and a bucket 6 is mounted at the end of the arm 5. The boom 4, the arm 5, and the bucket 6 as working elements constitute an excavation attachment device AT as an example of an attachment device. 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. A cab 10 is provided on the upper slewing body 3, and a power source such as an engine 11 is mounted.

[0023] A posture detection device M1 is mounted on the excavation attachment device AT. The posture detection device M1 is an example of a detection device as a device for detecting information related to the excavation reaction force. Specifically, the posture detection device M1 is configured to be able to detect the posture of the excavation attachment device AT. In the illustrated example, the posture detection device M1 includes a boom angle sensor M1a, an arm angle sensor M1b, and a bucket angle sensor M1c.

[0024] The boom angle sensor M1a is a sensor for obtaining the boom angle. For example, a rotation angle sensor for detecting the rotation angle of the boom foot pin, a stroke sensor for detecting the stroke amount of the boom cylinder 7, an inclination (acceleration) sensor for detecting the inclination angle of the boom 4, and the like. The same applies to the arm angle sensor M1b and the bucket angle sensor M1c.

[0025] Further, a cab 10 as a driver's cab is provided on the upper slewing body 3, and a power source such as an engine 11 is mounted. The power source may also be an electric motor. Further, an object detection device 70 or the like is mounted on the upper slewing body 3. An operation device 26, a controller 30, a display device 40, a sound output device 45, and the like are provided inside the cab 10. In addition, in this specification, for convenience, the side of the upper slewing body 3 on which the boom 4 is mounted is defined as the front, and the side on which the counterweight is mounted is defined as the rear.

[0026] The object detection device 70 is configured to detect objects existing around the excavator 100. The objects are, for example, people, animals, vehicles, construction machinery, buildings, or pits. The object detection device 70 is, for example, an ultrasonic sensor, a millimeter-wave radar, a camera device, or an infrared sensor. The camera device is, for example, a monocular camera, a stereo camera, a LIDAR, or a distance image sensor. In the illustrated example, the object detection device 70 includes a rear camera 70B mounted at the rear end of the upper surface of the upper swing body 3, a front camera 70F mounted at the front end of the upper surface of the cab 10, a left camera 70L mounted at the left end of the upper surface of the upper swing body 3, and a right camera 70R mounted at the right end of the upper surface of the upper swing body 3.

[0027] The object detection device 70 may also be configured to be able to detect a specified object (for example, a person) within a specified area set around the excavator 100. For example, the object detection device 70 may be configured to be able to distinguish and detect a person and an object other than a person.

[0028] Figure 2 It is a side view of the excavator 100 showing various physical quantities related to the excavation attachment AT. The boom angle sensor M1a acquires, for example, the boom angle θ1. The boom angle θ1 is the angle of the line segment P1 - P2 connecting the boom foot pin position P1 and the bucket link pin position P2 with respect to the horizontal line in the XZ plane. The bucket arm angle sensor M1b acquires, for example, the bucket arm angle θ2. The bucket arm angle θ2 is the angle of the line segment P2 - P3 connecting the bucket link pin position P2 and the bucket tip link pin position P3 with respect to the horizontal line in the XZ plane. The bucket angle sensor M1c acquires, for example, the bucket angle θ3. The bucket angle θ3 is the angle of the line segment P3 - P4 connecting the bucket tip link pin position P3 and the bucket tip position P4 with respect to the horizontal line in the XZ plane. Additionally, the bucket angle θ3 may also be calculated based on the operation content of the operation device 26. For example, the bucket angle θ3 may be calculated based on the outputs of the pilot pressure sensors 15a, 15b, etc. In this case, the bucket angle sensor M1c may be omitted.

[0029] Next, referring to Figure 3 , the basic system of the excavator 100 will be described. The basic system of the excavator 100 mainly includes an engine 11, a main pump 14, a pilot pump 15, a control valve unit 17, an operation device 26, a controller 30, a display device 40, a sound output device 45, an engine control device 74, an operation mode changeover switch 75, a buried object detection mode switch 76, a posture detection device M1, and an excavation pressure sensor S1, etc.

[0030] The engine 11 is the drive source of the excavator 100. For example, it is a diesel engine that operates in a manner to maintain a specified 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.

[0031] The main pump 14 is a device that supplies working oil to the control valve unit 17 via the working oil pipeline 16, for example, an inclined plate type variable capacity hydraulic pump. In an inclined plate type variable capacity hydraulic pump, the stroke length of the piston that determines the displacement changes according to the change in the inclined plate deflection angle, so that the discharge flow rate per revolution changes. The inclined plate deflection angle is controlled by the regulator 14a. The regulator 14a changes the inclined plate deflection angle according to the change in the control current from the controller 30. For example, the regulator 14a increases the inclined plate deflection angle according to the increase in the control current, thereby increasing the discharge flow rate of the main pump 14. Or, the regulator 14a decreases the inclined plate deflection angle according to the decrease in the control current, thereby reducing the discharge flow rate of the main pump 14. The discharge pressure sensor 14b detects the discharge pressure of the main pump 14. The oil temperature sensor 14c detects the temperature of the working oil sucked by the main pump 14.

[0032] The pilot pump 15 is a hydraulic pump for supplying working oil to various hydraulic control devices such as the operating device 26 via the pilot pipeline 25, for example, a fixed capacity hydraulic pump.

[0033] The control valve unit 17 is configured to be able to control the flow of working oil related to the hydraulic actuator. In the illustrated example, the control valve unit 17 includes a plurality of flow control valves. The control valve unit 17 selectively supplies the working oil received from the main pump 14 through the working oil pipeline 16 to one or more hydraulic actuators according to the change in the pressure (pilot pressure) corresponding to the operation direction and operation amount of the operating device 26. The hydraulic actuators include, for example, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the left travel hydraulic motor 1A, the right travel hydraulic motor 1B, and the swing hydraulic motor 2A. In the illustrated example, the hydraulic motors (the left travel hydraulic motor 1A, the right travel hydraulic motor 1B, and the swing hydraulic motor 2A) are inclined plate type piston motors. However, at least one of the hydraulic motors can be an electric motor.

[0034] The operating device 26 is a device for the operator to operate the hydraulic actuator, including the lever 26A, the lever 26B, the pedal 26C, etc. The operating device 26 receives the supply of working oil from the pilot pump 15 via the pilot pipeline 25 and generates a pilot pressure. Moreover, the operating device 26 applies this pilot pressure to the pilot port of the corresponding flow control valve through the pilot pipeline 25a. The pilot pressure changes according to the operation direction and operation amount of the operating device 26. The operating device 26 can also be remotely operated. At this time, the operating device 26 generates a pilot pressure according to the information related to the operation direction and operation amount received via wireless communication.

[0035] The operating device 26 may also be an electric operating device instead of the hydraulic operating device described above. In this case, a solenoid valve for adjusting the pilot pressure may be arranged between the flow control valve in the control valve unit 17 and the pilot pump 15. Moreover, information related to the operating direction and operating amount of the electric operating device is sent to the controller 30 as an electric signal from the electric operating device. The controller 30 adjusts the opening area of the solenoid valve according to the electric signal received from the electric operating device, and thus can adjust the magnitude of the pilot pressure acting on the flow control valve.

[0036] The controller 30 is a control device for controlling the excavator 100. In the illustrated example, the controller 30 is composed of a computer having a CPU, a volatile storage device, a non-volatile storage device, and the like. The CPU of the controller 30 reads programs corresponding to various functions from the non-volatile storage device, loads them into the volatile storage device, and executes them, thereby implementing functions corresponding to each of these programs.

[0037] For example, the controller 30 implements a function of controlling the discharge flow rate of the main pump 14. Specifically, the controller 30 changes the magnitude of the control current relative to the regulator 14a according to the pressure of the working oil in the negative control valve, and controls the discharge flow rate of the main pump 14 via the regulator 14a.

[0038] The display device 40 is a device for displaying various information, and is arranged near the driver's seat in the cab 10. In the illustrated example, the display device 40 has an image display unit 41 and an input unit 42. The image display unit 41 is a liquid crystal display. The input unit 42 is a membrane switch. The operator can input information or instructions to the controller 30 by using the input unit 42. And the operator can grasp the operating condition or control information of the excavator 100 by observing the image display unit 41. The display device 40 is connected to the controller 30 via a communication network such as CAN. However, the display device 40 may also be connected to the controller 30 via a dedicated line.

[0039] The display device 40 operates by receiving power supply from the storage battery 90. In the illustrated example, the storage battery 90 is charged by the power generated by the alternator 11a. The power of the storage battery 90 is also supplied to other devices such as the electrical fittings 72 of the excavator 100 other than the controller 30 and the display device 40. The starter 11b of the engine 11 can be driven by the power from the storage battery 90 to start the engine 11.

[0040] The sound output device 45 is a device for outputting sound information. In the illustrated example, the sound output device 45 is a speaker arranged near the driver's seat in the cab 10. The sound output device 45 may be a buzzer.

[0041] The engine control device 74 is a device that controls the engine 11. The engine control device 74 controls, for example, the fuel injection amount and the like to achieve the engine speed set via the input device.

[0042] The engine 11 is controlled by the engine control device 74. The engine control device 74 sends various data indicating the state of the engine 11 (for example, data related to physical quantities such as data indicating the coolant water temperature detected by the water temperature sensor 11c) to the controller 30. The controller 30 stores this data in the temporary storage unit (memory) 30a and can send it to the display device 40 and the like as needed. The same applies to data indicating the swash plate deflection angle output by the regulator 14a, data indicating the discharge pressure of the main pump 14 output by the discharge pressure sensor 14b, data indicating the working oil temperature output by the oil temperature sensor 14c, and data indicating the pilot pressure output by the pilot pressure sensors 15a and 15b.

[0043] The operation mode changeover switch 75 is a switch for changing the operation mode of the excavator 100 and is provided in the cab 10. In the illustrated example, by operating the operation mode changeover switch 75, the operator can switch between the M (manual) mode and the SA (semi-automatic) mode. The controller 30 is configured, for example, to change the operation mode of the excavator 100 according to the output of the operation mode changeover switch 75. Figure 3 Indicates the state in which the SA mode is selected by the operation mode changeover switch 75.

[0044] The M mode is a mode in which the excavator 100 operates according to the content of the operation input by the operator to the operation device 26. For example, it is a mode in which the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, etc. operate according to the content of the operation input by the operator to the operation device 26. The SA mode is a mode in which the excavator 100 automatically operates regardless of the content of the operation input to the operation device 26 when a specified condition is satisfied. For example, when a specified condition is satisfied, at least one of the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 automatically operates regardless of the content of the operation input to the operation device 26. The operation mode changeover switch 75 may also be configured to be able to switch between three or more operation modes.

[0045] The buried object detection mode switch 76 is a switch for activating the buried object detection function, and is provided in the cab 10. The buried object detection function is a function for detecting buried objects existing in the ground of the excavation target. In the illustrated example, the buried object detection function is configured to detect the presence or absence of buried objects based on the excavation reaction force. Also, in the illustrated example, the operator can switch the activation and stop of the buried object detection function by operating the buried object detection mode switch 76. The controller 30 is configured to switch the activation and stop of the buried object detection function according to the output of the buried object detection mode switch 76, for example. Specifically, the controller 30 is configured to activate the buried object detection function according to the start instruction from the buried object detection mode switch 76, and to stop the buried object detection function according to the stop instruction from the buried object detection mode switch 76. However, when it is determined that the excavation operation is in progress regardless of the operation of the buried object detection mode switch 76, based on the posture of the excavation attachment AT or the like, the controller 30 may activate the buried object detection function. At this time, the controller 30 may continuously execute the buried object detection function, for example, from the start of the excavation operation until the moment when the boom lifting operation is performed.

[0046] The excavation pressure sensor S1 is an example of a detection device that detects information related to the excavation reaction force, and detects the pressure of the working oil in hydraulic cylinders such as the boom cylinder 7, and outputs the detected data to the controller 30. In the illustrated example, the excavation pressure sensor S1 includes excavation pressure sensors S11 to S18. Specifically, the excavation pressure sensor S11 detects the pressure of the working oil in the bottom oil chamber of the boom cylinder 7, that is, the boom bottom pressure. Also, the excavation pressure sensor S12 detects the pressure of the working oil in the rod side oil chamber of the boom cylinder 7, that is, the boom rod pressure. Similarly, the excavation pressure sensor S13 detects the stick bottom pressure, the excavation pressure sensor S14 detects the stick rod pressure, the excavation pressure sensor S15 detects the bucket bottom pressure, and the excavation pressure sensor S16 detects the bucket rod pressure. The excavation pressure sensor S17 detects the pressure of the working oil in the first port (left port) of the swing hydraulic motor 2A, that is, the left swing pressure, and the excavation pressure sensor S18 detects the pressure of the working oil in the second port (right port) of the swing hydraulic motor 2A, that is, the right swing pressure.

[0047] The control valve E1 is a valve that operates according to an instruction from the controller 30. In the illustrated example, the control valve E1 is used to forcibly operate the flow control valve related to a specified hydraulic cylinder regardless of the content of the operation input to the operation device 26. In the case of adopting the above-described electric operation device, the control valve E1 corresponds to an electromagnetic valve disposed between the flow control valve and the pilot pump 15.

[0048] Figure 4 It indicates being mounted on Figure 1The figure of the structural example of the excavation control system of the excavator 100. The excavation control system mainly consists of a posture detection device M1, an excavation pressure sensor S1, an operation mode changeover switch 75, an underground object detection mode switch 76, a controller 30, a control valve E1, a display device 40, and a sound output device 45. The controller 30 includes an excavation reaction force calculation unit 31 and an underground object detection unit 32.

[0049] The excavation reaction force calculation unit 31 is a functional component that calculates the excavation reaction force. The excavation reaction force calculation unit 31 is configured to calculate the excavation reaction force based at least on the output of the excavation pressure sensor S1. In the illustrated example, the excavation reaction force calculation unit 31 calculates the excavation reaction force based on the output of the excavation pressure sensor S1 and the posture of the excavation attachment AT detected by the posture detection device M1. The excavation reaction force calculation unit 31 may additionally use the output of a vehicle body inclination sensor. The vehicle body inclination sensor may be composed of, for example, an acceleration sensor or a gyro sensor.

[0050] The output of the excavation pressure sensor S1 includes, for example, at least one of the boom bottom pressure (P11), boom rod pressure (P12), arm bottom pressure (P13), arm rod pressure (P14), bucket bottom pressure (P15), and bucket rod pressure (P16) detected by the excavation pressure sensors S11 to S16.

[0051] The excavation reaction force calculation unit 31 may calculate the cylinder thrust based on the output of the excavation pressure sensor S1. The cylinder thrust is calculated, for example, based on the excavation pressure and the pressure receiving area of the piston sliding in the cylinder. The cylinder thrust includes, for example, the boom cylinder thrust (f1), the arm cylinder thrust (f2), and the bucket cylinder thrust (f3). Specifically, as Figure 2 shown, the boom cylinder thrust (f1) is represented by the difference (P11×A11 - P12×A12) between the cylinder extension force (i.e., the product of the boom bottom pressure (P11) and the pressure receiving area (A11) of the piston in the boom bottom oil chamber (P11×A11)) and the cylinder contraction force (i.e., the product of the boom rod pressure (P12) and the pressure receiving area (A12) of the piston in the boom rod side oil chamber (P12×A12)). The same applies to the arm cylinder thrust (f2) and the bucket cylinder thrust (f3).

[0052] The excavation reaction force calculation unit 31 may calculate the excavation torque based on the posture of the excavation attachment AT and the cylinder thrust. As Figure 2As shown, the magnitude of the bucket digging torque (τ3) is represented by the value obtained by multiplying the magnitude of the bucket cylinder thrust (f3) by the distance G3 between the line of action of the bucket cylinder thrust (f3) and the bucket connection pin position P3. The distance G3 is a function of the bucket angle θ3 and is an example of a link gain. The same applies to the boom digging torque (τ1) and the arm digging torque (τ2). Additionally, the distance G1 is the distance between the line of action of the boom cylinder thrust (f1) and the boom foot pin position P1, and the distance G2 is the distance between the line of action of the arm cylinder thrust (f2) and the arm connection pin position P2.

[0053] For example, as Figure 2 shown, the digging reaction force is calculated as the product of a mechanism function with the boom angle θ1, the arm angle θ2, and the bucket angle θ3 as independent variables and a function with the boom digging torque (τ1), the arm digging torque (τ2), and the bucket digging torque (τ3) as independent variables. The function with the boom digging torque (τ1), the arm digging torque (τ2), and the bucket digging torque (τ3) as independent variables can be a function with the boom cylinder thrust (f1), the arm cylinder thrust (f2), and the bucket cylinder thrust (f3) as independent variables.

[0054] The function with the boom angle θ1, the arm angle θ2, and the bucket angle θ3 as independent variables can be a function based on the force balance equation, a function based on the Jacobian matrix, or a function based on the principle of imaginary work.

[0055] In this way, the value of the digging reaction force is derived based on the detection values of various sensors at the current moment. However, the detection value of the digging pressure sensor S1 can also be directly used as the value of the digging reaction force. Or, the value of the cylinder thrust calculated based on the detection value of the digging pressure sensor S1 can be used as the value of the digging reaction force. Or, the value of the digging torque calculated from the value of the cylinder thrust calculated based on the detection value of the digging pressure sensor S1 and the value related to the posture of the digging attachment AT derived from the detection value of the posture detection device M1 can be used as the value of the digging reaction force.

[0056] The digging reaction force calculation unit 31 can calculate the digging reaction force acting in the turning direction based on the outputs of the digging pressure sensors S17 and S18. In the illustrated example, when the left turning pressure (P17) detected by the digging pressure sensor S17 is greater than the right turning pressure (P18) detected by the digging pressure sensor S18, the upper slewing body 3 attempts to turn to the left. Also, when the right turning pressure (P18) detected by the digging pressure sensor S18 is greater than the left turning pressure (P17) detected by the digging pressure sensor S17, the upper slewing body 3 attempts to turn to the right. The digging reaction force calculation unit 31 can, for example, calculate the left turning pressure (P17) when the left turning pressure (P17) is greater than the right turning pressure (P18) as the digging reaction force acting in the left turning direction. Also, the digging reaction force calculation unit 31 can, for example, calculate the right turning pressure (P18) when the right turning pressure (P18) is greater than the left turning pressure (P17) as the digging reaction force acting in the right turning direction. Further, in the case where a turning electric motor is mounted instead of the turning hydraulic motor 2A, the digging reaction force calculation unit 31 can also calculate the digging reaction force acting in the turning direction based on information related to electricity such as the direction and magnitude of the current supplied to the turning electric motor.

[0057] The buried object detection unit 32 is configured to be able to detect a buried object based on information related to the digging reaction force. In the illustrated example, the buried object detection unit 32 is configured to be able to infer (determine) the presence or absence of a buried object based on the digging reaction force calculated by the digging reaction force calculation unit 31.

[0058] Moreover, the buried object detection unit 32 outputs a control command to the control valve E1, for example, when it infers that a buried object is present.

[0059] The control valve E1 is configured such that when receiving a control instruction from the buried object detection unit 32, regardless of the content of the operation input to the operation device 26, it can forcibly operate the flow control valve associated with a specified hydraulic cylinder to forcibly extend or retract the specified hydraulic cylinder. In the illustrated example, the control valve E1 is configured such that even when the boom operation lever is not operated, it can forcibly extend the boom cylinder 7 by forcibly moving the flow control valve associated with the boom cylinder 7. As a result, the control valve E1 can make the excavation depth shallower by forcibly raising the boom 4. Alternatively, even when the arm operation lever is operated, the control valve E1 can forcibly stop the arm cylinder 8 by forcibly moving the flow control valve associated with the arm cylinder 8. At this time, the control valve E1 can suppress the bucket 6 from contacting the buried object by forcibly stopping the arm 5. Thus, the control valve E1 can, according to the control instruction from the buried object detection unit 32, forcibly extend, retract, or stop at least one of the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, thereby suppressing the excavation attachment AT from contacting the buried object.

[0060] When it is inferred that there is a buried object, the buried object detection unit 32 can output a control instruction to the display device 40. The display device 40 can be configured to display the inferred position of the buried object when receiving the control instruction from the buried object detection unit 32. For example, the display device 40 can display a virtual viewpoint image representing the state of the excavator 100 when viewed from a virtual viewpoint directly above the excavator 100, and superimpose a graphic related to the actually invisible buried object buried underground on this virtual viewpoint image. In the illustrated example, the virtual viewpoint image is generated based on the images acquired by the rear camera 70B, the left camera 70L, and the right camera 70R respectively. Additionally, when synthesizing the virtual viewpoint image, the image acquired by the front camera 70F can be additionally utilized. Alternatively, the display device 40 can display an image representing the cross-section of the ground where the excavator 100 is located, and superimpose a graphic related to the actually invisible buried object buried underground on this virtual viewpoint image.

[0061] When it is inferred that there is a buried object, the buried object detection unit 32 can output a control instruction to the sound output device 45. When receiving the control instruction from the buried object detection unit 32, the sound output device 45 can output a voice message for notifying the operator of the existence of the buried object. Alternatively, the sound output device 45 can output an alarm sound for notifying the operator of the existence of the buried object.

[0062] The controller 30 can be configured to activate the buried object detection function according to the activation instruction from the buried object detection mode switch 76. In the illustrated example, when the buried object detection function is activated, the buried object detection unit 32 can infer the presence or absence of a buried object based on the excavation reaction force calculated by the excavation reaction force calculation unit 31. On the other hand, the controller 30 can be configured to stop the buried object detection function according to the stop instruction from the buried object detection mode switch 76. In the illustrated example, when the buried object detection function is stopped, the buried object detection unit 32 does not infer the presence or absence of a buried object. This is to prevent erroneously inferring the presence of a buried object based on fluctuations in the excavation reaction force and outputting control instructions to the control valve E1, the display device 40, or the sound output device 45 when there is clearly no buried object.

[0063] When the buried object detection function is stopped, the excavation reaction force calculation unit 31 can be configured not to calculate the excavation reaction force. This is to reduce the computational load.

[0064] In the illustrated example, the buried object detection function is configured to execute regardless of whether the operating mode of the excavator 100 is the M (manual) mode or the SA (semi-automatic) mode. However, the buried object detection function can also be configured to execute only when the SA (semi-automatic) mode is selected. This is because when the SA (semi-automatic) mode is selected, the operator can move the excavation attachment AT along a pre-set target track, and as a result, the detection accuracy of buried objects can be improved. When the SA (semi-automatic) mode is selected, for example, a primary excavation operation (a series of actions from when the tip of the bucket 6 inserts into the ground until the bucket 6 separates from the ground) for finding buried objects can be automatically executed when the buried object detection mode switch 76 is operated. That is, each excavation operation can be automatically executed each time the buried object detection mode switch 76 is operated.

[0065] In addition, the target track is, for example, a track that a specified part of the excavation attachment AT should follow. The specified part of the excavation attachment AT is, for example, the tip of the bucket 6.

[0066] Next, referring to Figure 5 , the operation of the excavator 100 when the operator of the excavator 100 finds the water pipe U1 as a buried object will be described. Figure 5 Fig. shows a cross-section of the foundation in which the water pipe U1 is buried. The excavator 100 is located on this foundation.

[0067] In Figure 5In the example shown, the operator of the excavator 100 first operates the operation mode changeover switch 75 to change the operation mode of the excavator 100 to the SA (semi-automatic) mode. On this basis, the operator manually operates the operating device 26 to move the tip of the bucket 6 to a desired position. The desired position is, for example, a position directly above the location where the tip of the bucket 6 should penetrate. Moreover, after moving the tip of the bucket 6 to the desired position, the operator operates the buried object detection mode switch 76 to activate the buried object detection function.

[0068] In the illustrated example, in the SA (semi-automatic) mode, when the buried object detection function is activated, the controller 30 causes the excavation attachment AT to operate autonomously. Specifically, the controller 30 automatically extends and retracts at least one of the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 so that a specified part of the excavation attachment AT moves along a preset target track TP. However, the controller 30 may also be configured such that, even when the buried object detection function is activated, like in the case of the M (manual) mode, the excavation attachment AT does not operate autonomously. At this time, the excavation attachment AT operates according to the operation content of the operator on the operating device 26.

[0069] In Figure 5 the example shown, the operator activates the buried object detection function after moving the tip of the bucket 6 to the first position PS1. The first position PS1 is a position on the ground ES before excavation. Figure 5 The ground ES before excavation is shown by a dashed line in the figure. When the buried object detection function is activated, the controller 30 causes the excavation attachment AT to operate automatically so that the tip of the bucket 6 moves along a preset first target track TP1 (dotted-dashed line).

[0070] Moreover, when the tip of the bucket 6 moves along the first target track TP1, the excavation reaction force calculation unit 31 repeatedly calculates the excavation reaction force based on the output of the posture detection device M1 and the output of the excavation pressure sensor S1 at a specified control cycle.

[0071] And, when the tip of the bucket 6 moves along the first target track TP1, the buried object detection unit 32 repeatedly infers the presence or absence of a buried object based on the excavation reaction force calculated by the excavation reaction force calculation unit 31 at a specified control cycle.

[0072] When the tip of the bucket 6 reaches the terminal of the first target track TP1, the controller 30 stops the autonomous operation of the excavation attachment AT. This indicates that the buried object detection unit 32 has not detected a buried object until the tip of the bucket 6 reaches the terminal of the first target track TP1.

[0073] After that, the operator operates the buried object detection mode switch 76 to stop the buried object detection function. When the operator manually operates the operating device 26 to perform a boom lifting action or a boom lifting and slewing action, the controller 30 can stop the buried object detection function. After that, after the operator performs a soil discharging action and a boom lowering and slewing action, the operator moves the tip of the bucket 6 to the next desired position in order to perform the next excavation action. In Figure 5 In the example shown, the operator manually operates to discharge the sand in the bucket 6, and then moves the tip of the bucket 6 to the second position PS2. At least one of the discharging of the sand in the bucket 6 and the movement to the second position PS2 can be performed automatically. The second position PS2 is a position on the first exposed surface exposed by the previous excavation action. Specifically, the second position PS2 on the first exposed surface is located at a depth D1 from the ground ES before the start of excavation, and is a position directly below the first position PS1. After the operator moves the tip of the bucket 6 to the second position PS2, the buried object detection function is started. When the buried object detection function is started, the controller 30 automatically operates the excavation attachment AT so that the tip of the bucket 6 moves along a preset second target track TP2 (dotted line).

[0074] Moreover, when the tip of the bucket 6 moves along the second target track TP2, the excavation reaction force calculation unit 31 repeatedly calculates the excavation reaction force based on the output of the posture detection device M1 and the output of the excavation pressure sensor S1 at a prescribed control cycle.

[0075] And, when the tip of the bucket 6 moves along the second target track TP2, the buried object detection unit 32 repeatedly infers the presence or absence of a buried object based on the excavation reaction force calculated by the excavation reaction force calculation unit 31 at a prescribed control cycle.

[0076] When the tip of the bucket 6 reaches the end of the second target track TP2, the controller 30 stops the autonomous operation of the excavation attachment AT. This means that the buried object detection unit 32 has not detected a buried object until the tip of the bucket 6 reaches the end of the second target track TP2.

[0077] After that, the operator operates the buried object detection mode switch 76 to stop the buried object detection function. When the operator manually operates the operating device 26 to perform a boom lifting action or a boom lifting and slewing action, the controller 30 can stop the buried object detection function. After that, after the operator performs a soil discharging action and a boom lowering and slewing action, the operator moves the tip of the bucket 6 to the next desired position in order to perform the next excavation action. In Figure 5In the example shown, the operator moves the tip of the bucket 6 to the third position PS3. The third position PS3 is a position on the second exposed surface that was exposed by the previous excavation operation. Specifically, the third position PS3 on the second exposed surface is located at a depth D2 from the first exposed surface and is a position directly below the second position PS2. In Figure 5 the example shown, the depth D2 is the same as the depth D1. After the operator moves the tip of the bucket 6 to the third position PS3, the buried object detection function is activated. When the buried object detection function is activated, the controller 30 causes the excavation attachment AT to automatically operate so that the tip of the bucket 6 moves along a preset third target track TP3 (dotted line).

[0078] Moreover, when the tip of the bucket 6 moves along the third target track TP3, the excavation reaction force calculation unit 31 repeatedly calculates the excavation reaction force based on the output of the posture detection device M1 and the output of the excavation pressure sensor S1 at a prescribed control cycle.

[0079] And, when the tip of the bucket 6 moves along the third target track TP3, the buried object detection unit 32 repeatedly infers the presence or absence of a buried object based on the excavation reaction force calculated by the excavation reaction force calculation unit 31 at a prescribed control cycle.

[0080] In Figure 5 the example shown, the buried object detection unit 32 infers the presence of a buried object when the tip of the bucket 6 reaches the fourth position PS4. The fourth position PS4 is located at a depth D3 from the second exposed surface and is a position on the third target track TP3. In Figure 5 the example shown, the depth D3 is the same as the depth D1 and the depth D2, respectively. And, the fourth position PS4 is a position where the distance between the water pipe U1 and the tip of the bucket 6 in the direction of the third target track TP3 becomes a value AD1. Additionally, in Figure 5 the example shown, the direction along the third target track TP3 is the horizontal direction.

[0081] Here, with reference to Figure 6 , the detailed content of the process in which the buried object detection unit 32 infers the presence or absence of a buried object based on the output of the excavation reaction force calculation unit 31 will be described. Figure 6 is a graph showing the relationship between the excavation reaction force F and the approach distance AD. Figure 6 The vertical axis of Figure 6 corresponds to the excavation reaction force F calculated by the excavation reaction force calculation unit 31, Figure 5 and the horizontal axis of Figure 6 corresponds to the approach distance AD. In Figure 6 the example shown, the approach distance AD is the distance between the current position of the tip of the bucket 6 and the water pipe U1 in the direction of the target track TP. Figure 6It means that before the approach distance AD becomes zero, the approach distance AD decreases from the left side to the right side of the horizontal axis. That is, the tip of the bucket 6 when the approach distance AD is the value AD0 is located at a position farther from the water pipe U1 than when the approach distance AD is the value AD1.

[0082] Specifically, Figure 6 the first transition TL1 shown by the single-dashed line in represents the relationship between the excavation reaction force repeatedly calculated at a prescribed control cycle and the approach distance AD when the excavation attachment AT operates autonomously or semi-autonomously and the tip of the bucket 6 moves along the first target track TP1 (refer to Figure 5 .). And, Figure 6 the second transition TL2 shown by the dotted line in represents the relationship between the excavation reaction force repeatedly calculated at a prescribed control cycle and the approach distance AD when the excavation attachment AT operates autonomously or semi-autonomously and the tip of the bucket 6 moves along the second target track TP2 (refer to Figure 5 .). Moreover, Figure 6 the third transition TL3 shown by the solid line in represents the relationship between the excavation reaction force repeatedly calculated at a prescribed control cycle and the approach distance AD when the excavation attachment AT operates autonomously or semi-autonomously and the tip of the bucket 6 moves along the third target track TP3 (refer to Figure 5 .).

[0083] All of the first transition TL1 to the third transition TL3 represent a state where the excavation reaction force F increases with a substantially constant increase rate as the approach distance AD decreases. This is because as the bucket 6 approaches the machine body (the upper swing body 3), the amount of sandy soil entering the bucket 6 increases.

[0084] In the first transition TL1 and the second transition TL2, when the approach distance AD approaches zero and when the approach distance AD exceeds zero and moves away from zero, this increasing trend of the excavation reaction force F continues at substantially the same increase rate in either case. This is because there is no water pipe U1 on the target track TP (the first target track TP1 and the second target track TP2). In addition, the points (the values of the excavation reaction force F) on the first transition TL1 and the second transition TL2 when the approach distance AD is zero represent the values of the excavation reaction force F when the tip of the bucket 6 is directly above the water pipe U1.

[0085] On the other hand, at the moment when the approach distance AD becomes the value AD0 in the third transition TL3, its increase rate changes significantly (increases). This is because there is a water pipe U1 on the third target track TP3, and as the tip of the bucket 6 gets closer and closer to the water pipe U1, the sandy soil located between the bucket 6 and the water pipe U1 is compressed between the two.

[0086] Figure 6It shows a state where the excavation reaction force F becomes the value F0 when the approach distance AD is the value AD0, and the excavation reaction force F becomes the value F1 when the approach distance AD is the value AD1. Also, Figure 5 It shows a state where the approach distance AD becomes the value AD1 when the tip of the bucket 6 reaches the fourth position PS4 on the third target orbit TP3.

[0087] In the illustrated example, the buried object detection unit 32 is configured to infer the existence of a buried object when the value of the excavation reaction force F is greater than a specified excavation reaction force threshold Ft. The specified excavation reaction force threshold Ft is a value pre-stored in a non-volatile storage device or the like. However, the specified excavation reaction force threshold Ft can also be a dynamically set value. For example, the specified excavation reaction force threshold Ft can be derived based on the value of the excavation reaction force F calculated during a previous excavation operation.

[0088] Alternatively, the buried object detection unit 32 can be configured to infer the existence of a buried object when the average increase rate of the excavation reaction force F related to the approach distance AD is greater than a specified threshold.

[0089] Also, the buried object detection unit 32 can be configured to infer the presence or absence of a buried object based on the magnitude of the horizontal component or the vertical component of the excavation reaction force F.

[0090] Here, with reference to Figure 7 , an example of the output image displayed on the image display unit 41 of the display device 40 when the buried object detection unit 32 detects the water pipe U1 will be described. Figure 7 It is a diagram showing an example of the output image displayed on the image display unit 41. As Figure 7 shown, the image display unit 41 schematically shows the relationship between the bucket 6 and the buried object (water pipe U1). Buried objects such as the underground water pipe U1 are actually in an invisible state. Therefore, in Figure 7 the example shown, the controller 30 obtains the position information of the buried object from the construction information. The construction information is, for example, pre-stored in a non-volatile storage device or the like. The construction information can include two-dimensional or three-dimensional construction drawing data in addition to the position information of the buried object.

[0091] Specifically, Figure 7 the relationship between the excavation auxiliary device AT and the buried object when viewed from directly above is schematically shown by the bucket graphic G11, the arm graphic G12, the buried object graphic G13, and the approach limit line G14. Also, Figure 7 the output image shown represents the state at the beginning of the fourth excavation operation after the water pipe U1 is detected by the third excavation operation shown in Figure 5 shown. Also, Figure 7The output image shown indicates that the greater the density (thickness) of the dot pattern, the greater the excavation depth. Additionally, Figure 7 The output image shown is displayed full screen in the image display unit 41, but it may also be displayed in a part of the image display unit 41.

[0092] The bucket graphic G11 is a graphic representing the current state of the bucket 6. The arm graphic G12 is a graphic representing the current state of the arm 5. The display position, display shape, display size, etc. of the bucket graphic G11 and the arm graphic G12 are determined based on the output of the posture detection device M1 respectively. Additionally, the output image may include a boom graphic, which is a graphic representing the current state of the boom 4.

[0093] The buried object graphic G13 is a graphic representing the position and size of the buried object. In Figure 7 the example shown, the buried object graphic G13 includes a buried object graphic G13A generated based on the construction information and a buried object graphic G13B generated based on the detection result of the buried object detection unit 32.

[0094] The approach limit line G14 is a graphic representing the position and size of the approach limit area set around the buried object. In Figure 7 the example shown, similar to the buried object graphic G13, the approach limit line G14 includes an approach limit line G14A corresponding to the buried object graphic G13A generated based on the construction information and an approach limit line G14B corresponding to the buried object graphic G13B generated based on the detection result of the buried object detection unit 32.

[0095] Before the buried object is detected by the buried object detection unit 32, the display device 40 does not display the buried object graphic G13B and the approach limit line G14B. This is because the display device 40 cannot determine the display positions of the buried object graphic G13B and the approach limit line G14B respectively. On the other hand, after the buried object is detected by the buried object detection unit 32, the display device 40 may omit the display of the buried object graphic G13A and the approach limit line G14A. This is because it is inferred that the buried object represented by the buried object graphic G13A actually exists at the position represented by the buried object graphic G13B.

[0096] The approach limit area is an area that restricts the entry of a specified part of the excavation attachment AT. In Figure 7In the example shown, the proximity restricted area is a space that includes the space where buried objects are judged to exist. The controller 30 alerts the operator to prevent a specified part of the excavation attachment AT, for example, from entering the proximity restricted area. Specifically, the controller 30 can, for example, use intermittent sounds from the sound output device 45 to notify the operator of the magnitude of the distance between the tip of the bucket 6 and the buried object. At this time, the controller 30 can shorten the interval of the intermittent sounds as the distance decreases. Also, when the tip of the bucket 6 enters the proximity restricted area, the controller 30 can issue an alarm to the operator via the sound output device 45. The alarm is, for example, a sound significantly louder than the intermittent sound. Further, the controller 30 can also use a bar gauge to indicate to the operator the magnitude of the distance between the tip of the bucket 6 and the buried object.

[0097] Moreover, the controller 30 can also autonomously control the operation of the excavation attachment AT to prevent a specified part of the excavation attachment AT from entering the proximity restricted area. Specifically, for example, when the operator manually performs a boom closing operation and it is judged that the tip of the bucket 6 will enter the proximity restricted area if no action is taken, the controller 30 can invalidate the boom closing operation. Alternatively, the controller 30 can also automatically extend the boom cylinder 7 to raise the boom 4 so that the tip of the bucket 6 does not enter the proximity restricted area.

[0098] In addition, the controller 30 can also display the buried object graphic G13A and the buried object graphic G13B simultaneously. This is to clearly indicate to the operator the degree of deviation of the buried object from its initial position or how the buried object has deformed. By observing such images, the operator can infer the deviation of other buried objects buried nearby. Also, the operator can predict the possible deviation of the buried object in the future.

[0099] Furthermore, the controller 30 can display auxiliary information represented by, for example, a single-dot dash line and double-headed arrows. The auxiliary information can, for example, include a sub-window that displays the detailed content of the buried object data and an image of speech bubbles that displays information related to the excavated material that has entered the bucket 6. The sub-window can, for example, display the period when the buried object was buried, the type of the buried object, the material of the buried object, or the size of the buried object. The image of the speech bubbles can, for example, display the weight of the sand that has entered the bucket 6.

[0100] Further, the auxiliary information may include the vertical distance between the proximity restricted area and the ground thereabove, the vertical distance between the buried object and the ground thereabove, the vertical distance between the tip of the bucket 6 and the buried object, the horizontal distance between the buried object and the ground (wall surface) on the side of the excavator 100, the horizontal distance between the tip of the bucket 6 and the buried object, or the back angle of the bucket, etc. The back angle of the bucket is the angle formed between a hypothetical plane including the back of the bucket 6 and a hypothetical horizontal plane.

[0101] In addition, the auxiliary information may also include information related to the horizontal or vertical offset between the position of the buried object based on the construction information and the position of the buried object based on the detection result of the buried object detection unit 32.

[0102] Moreover, the controller 30 may use a projector installed on the upper swing body 3 to project the output image as shown in Figure 7 onto the ground. At this time, the output image is preferably projected with the display of the bucket graphic G11 and the arm graphic G12 omitted, and the display position of the buried object graphic G13 coincides with the actual position of the buried object.

[0103] Next, referring to Figure 8 , another structural example of the excavation control system that can be mounted on the Figure 1 excavator 100 will be described. Figure 8 is a diagram showing another structural example of the excavation control system. Figure 8 The excavation control system of differs mainly from the excavation control system of that detects buried objects based on the excavation reaction force in that the images acquired by the front camera 70F, one of the object detection devices 70, are used to detect buried objects. Figure 4 In the excavation control system of , the front camera 70F also functions as a detection device for detecting information related to the ground bulged due to excavation, i.e., a detection device. In addition, the front camera 70F may be a camera device installed on the side or ventral surface of the arm 5, etc., a camera device installed on the excavation attachment AT.

[0104] In Figure 8 the excavation control system, the buried object detection unit 32 is configured to be able to detect buried objects based on information related to the ground bulged due to excavation. In the example shown in , the buried object detection unit 32 is configured to be able to infer the presence or absence of buried objects based on the images acquired by the front camera 70F.

[0105] Here, referring to , an example of the process by which the buried object detection unit 32 infers the presence or absence of buried objects will be described. Figure 8 is a diagram showing a cross-section of the ground where a water pipe U1 as a buried object is buried.

[0106] Here, referring to , an example of the process by which the buried object detection unit 32 infers the presence or absence of buried objects will be described. Figure 9 is a diagram showing a cross-section of the ground where a water pipe U1 as a buried object is buried. Figure 9 is a diagram showing a cross-section of the ground where a water pipe U1 as a buried object is buried.Figure 9 The position indicated by the dashed circle PT1 represents the excavation start position. Figure 9 The position indicated by the dashed circle PT2 represents the position of the tip of the bucket. Figure 9 The position indicated by the dashed circle PT3 represents the position of the front end of the sand pile. Additionally, in Figure 9 , for clarification, a sparse dot pattern is marked on the cross-section of the foundation of the excavation target, and a dense dot pattern is marked on the cross-section of the sand pile formed by the raised ground.

[0107] The position of the tip of the bucket represents the position of the tip of the bucket 6. The buried object detection unit 32 can calculate the position of the tip of the bucket based on the output of the posture detection device M1. Additionally, the buried object detection unit 32 can also calculate the position of the tip of the bucket based on the image acquired by the front camera 70F.

[0108] The excavation start position represents the position where excavation starts. In the illustrated example, the excavation start position is the position of the tip of the bucket when the tip of the bucket 6 contacts the ground of the excavation target. The buried object detection unit 32 can determine whether the tip of the bucket 6 contacts the ground based on the output of the excavation pressure sensor S1. Additionally, the buried object detection unit 32 can also determine whether the tip of the bucket 6 contacts the ground based on the image acquired by the front camera 70F. And the buried object detection unit 32 can also calculate the excavation start position based on the image acquired by the front camera 70F.

[0109] Figure 9 The position indicated by the dashed circle PT3, i.e., the position of the front end of the sand pile, represents the position of the near-front edge of the ground raised by excavation. In the illustrated example, the buried object detection unit 32 can calculate the position of the front end of the sand pile based on the image acquired by the front camera 70F. At this time, the buried object detection unit 32 can, for example, determine the range of the ground raised by excavation (the range of the sand pile) based on the image of the ground before excavation and the image of the ground during excavation. For example, the buried object detection unit 32 can use the range where there is a change in the image due to excavation as the range of the sand pile. Or the buried object detection unit 32 can also calculate the distance between the front camera 70F and each point on the ground surface based on the image acquired by the front camera 70F. Moreover, the buried object detection unit 32 can use the part that has been raised by more than a specified height due to excavation as the range of the sand pile.

[0110] In the illustrated example, the buried object detection unit 32 repeatedly calculates the position of the tip of the bucket and the position of the front end of the sand pile at a specified calculation cycle. And the buried object detection unit 32 repeatedly calculates the distances DS1, DS2, and DS3 at a specified calculation cycle based on the calculated excavation start position, the position of the tip of the bucket, and the position of the front end of the sand pile. Additionally, the buried object detection unit 32 can also omit the calculation of the distance DS3.

[0111] The distance DS1 is the distance (horizontal distance) between the excavation start position and the bucket tip position in the front-rear direction, corresponding to the "excavation length". The front-rear direction is the direction parallel to the front-rear axis of the excavator 100. Moreover, the front-rear axis of the excavator 100 is an axis perpendicular to the rotation axis of the excavator 100 and perpendicular to the left-right axis of the excavator 100, and extends in the direction bisecting the excavation attachment AT when viewed from above. The left-right axis of the excavator 100 is an axis perpendicular to the rotation axis of the excavator 100 and perpendicular to the front-rear axis of the excavator 100. The distance DS2 is the distance (horizontal distance) between the bucket tip position and the front end position of the sand pile in the front-rear direction. The distance DS3 is the distance (vertical distance) between the excavation start position and the bucket tip position in the up-down direction, corresponding to the "excavation depth". The up-down direction is the direction parallel to the rotation axis of the excavator 100. Additionally, the bucket tip position for determining the distances DS1, DS2, and DS3 can be replaced by a monitoring position such as the position of the connecting pin connecting the arm 5 and the bucket 6 or the end position of the rod of the bucket cylinder 9. At this time, the buried object detection unit 32 can calculate the monitoring position based on the image acquired by the front camera 70F. This is because these monitoring positions are less likely to be buried underground compared to the bucket tip position.

[0112] Furthermore, the buried object detection unit 32 infers the presence or absence of a buried object based on the comparison result between the distance DS2 and a predetermined distance threshold. Specifically, the buried object detection unit 32 infers the presence of a buried object when the distance DS2 is less than the distance threshold. When there is a buried object in the traveling direction of the bucket 6, the ground heave is suppressed by the buried object, and the near-front edge of the ground heaving due to excavation (including Figure 9 the edge of the front end position of the sand pile indicated by the dashed circle PT3) is formed closer to the bucket 6 compared to the case where there is no buried object.

[0113] In the non-volatile storage device of the controller 30, the correspondence relationship between the distance DS1 and the distance threshold is pre-stored as a reference table. The buried object detection unit 32 can refer to this reference table and repeatedly derive the distance threshold corresponding to the calculated current distance DS1 at a prescribed calculation cycle. In the illustrated example, the distance threshold is set such that the larger the distance DS1, that is, the farther the bucket tip position is from the excavation start position, the larger the distance threshold. Additionally, in the non-volatile storage device of the controller 30, the correspondence relationship between the distance DS1, the distance DS3, and the distance threshold can be pre-stored as a reference table. At this time, the buried object detection unit 32 can repeatedly derive the distance threshold corresponding to the calculated current distance DS1 (excavation length) and the distance DS3 (excavation depth) at a prescribed calculation cycle. Moreover, considering differences such as the shape of the bucket 6, the characteristics of the sand (viscosity, etc.), or the type of sand, multiple reference tables can be selectively stored in the non-volatile storage device of the controller 30. At this time, information related to the shape of the bucket 6, the characteristics of the sand (viscosity, etc.), or the type of sand can be input to the controller 30 before excavation is performed.

[0114] The buried object detection unit 32 infers the presence or absence of a buried object by comparing the distance threshold derived by referring to the reference table with the current distance DS2. In the illustrated example, the buried object detection unit 32 repeatedly infers the presence or absence of a buried object at the same inference cycle as the prescribed calculation cycle from the moment the tip of the bucket 6 contacts the ground until the moment the tip of the bucket 6 separates from the ground. Additionally, the buried object detection unit 32 can, for example, determine that the tip of the bucket 6 has separated from the ground when the distance DS3 becomes zero.

[0115] And Figure 4 in the case of the excavation control system of Figure 8 the buried object detection unit 32 of the excavation control system can output a control command to the control valve E1, can also output a control command to the display device 40, and can also output a control command to the sound output device 45 when it is inferred that there is a buried object.

[0116] Moreover, Figure 8 the controller 30 of the excavation control system can be configured Figure 4 similarly to the case of the excavation control system of Figure 8 to start the buried object detection function according to a start instruction from the buried object detection mode switch 76. In the

[0117] In Figure 8 the illustrated example, when the buried object detection function is started, the buried object detection unit 32 can infer the presence or absence of a buried object based on the image acquired by the front camera 70F. On the other hand, the controller 30 can be configured to stop the buried object detection function according to a stop instruction from the buried object detection mode switch 76.

[0117] In Figure 8 the illustrated example, similar toFigure 4 Similarly, in the case of the excavation control system of the present invention, the buried object detection function can be configured to be executed regardless of whether the operation mode of the excavator 100 is the M (manual) mode or the SA (semi-automatic) mode. However, the buried object detection function can also be configured to be executed only when the SA (semi-automatic) mode is selected.

[0118] When SA (semi-automatic) mode is selected, Figure 4 Similarly, when the buried object detection mode switch 76 is operated, a digging action (a series of actions from the tip of the bucket 6 being inserted into the ground to the bucket 6 being separated from the ground) for finding the buried object is automatically executed. That is, each digging action can be automatically executed each time the buried object detection mode switch 76 is operated.

[0119] And, with Figure 4 Similarly, in the case of the excavation control system, the Figure 8 The controller 30 of the excavation control system may include an excavation reaction force calculation unit 31. At this time, the buried object detection unit 32 may infer that there is a buried object when the value of the excavation reaction force F calculated by the excavation reaction force calculation unit 31 is greater than a predetermined excavation reaction force threshold Ft and when the distance DS2 is less than the distance threshold.

[0120] Alternatively, when the value of the excavation reaction force F calculated by the excavation reaction force calculation unit 31 is greater than the excavation reaction force threshold value Ft, the buried object detection unit 32 may also start to derive the distance DS1, the distance DS2 and the distance threshold value. On this basis, when the distance DS2 is less than the distance threshold value, the buried object detection unit 32 may infer that there is a buried object. On the contrary, when the distance DS2 is less than the distance threshold value, the buried object detection unit 32 may start to calculate the excavation reaction force F. On this basis, when the value of the excavation reaction force F is greater than the excavation reaction force threshold value Ft, the buried object detection unit 32 may infer that there is a buried object. This is to reduce the computational load of the controller 30.

[0121] Next, refer to Figure 10 , an example of a process in which the buried object detection unit 32 estimates the configuration of the buried object is described. Figure 10 It is a top view of the excavation attachment AT during the excavation operation. Figure 10 The dotted rectangle in FIG. 1 represents the configuration of the buried object U which is actually invisible and buried underground. Figure 10 In the embodiment, the embedded object U is a horizontally extending rod-shaped member. Figure 10 In order to make it clear, the ground of the excavation object is marked with a sparse dot pattern, the sand pile formed by the raised ground is marked with a dense dot pattern, and the hole formed by the excavation is marked with a cross pattern. Specifically,Figure 10 The left figure shows the buried object U (buried object U11) buried in such a manner as to extend horizontally (perpendicular to the front-rear direction) in the vicinity of the front side of the bucket 6 when observed from the driver's seat in the cockpit 10. Figure 10 The central figure shows the buried object U (buried object U12) buried in such a manner that the left end is closer to the cockpit 10 than the right end (tilted with respect to the front-rear direction). Figure 10 The right figure shows the buried object U (buried object U13) buried in such a manner that the right end is closer to the cockpit 10 than the left end (tilted with respect to the front-rear direction).

[0122] The buried object detection unit 32 infers the configuration of the buried object U based on information related to the ground lifted by excavation. In the illustrated example, the buried object detection unit 32 repeatedly calculates the left front end position and the right front end position at a prescribed calculation cycle. The left front end position represents the position of the edge on the near front left side of the ground lifted by excavation (the position closest to the cockpit 10), and the right front end position represents the position of the edge on the near front right side of the ground lifted by excavation (the position closest to the cockpit 10). "Left side" means the left side of the center plane CP of the excavation attachment AT, and "right side" means the right side of the center plane CP of the excavation attachment AT. The center plane CP of the excavation attachment AT is a plane including the front-rear axis of the excavator 100 and including the rotation axis of the excavator 100. In the illustrated example, the buried object detection unit 32 can calculate the left front end position and the right front end position based on the image acquired by the front camera 70F. Further, the buried object detection unit 32 repeatedly calculates the distances DS2 (left side distance DS2L and right side distance DS2R) at a prescribed calculation cycle based on the calculated left front end position and right front end position.

[0123] The left side distance DS2L is the distance between the bucket tip position and the left front end position in the front-rear direction. The right side distance DS2R is the distance between the bucket tip position and the right front end position in the front-rear direction.

[0124] Moreover, when it is inferred that there is a buried object U based on the excavation reaction force or the like, the buried object detection unit 32 infers the configuration of the buried object U based on the comparison result between the left side distance DS2L and the right side distance DS2R. In addition, the buried object detection unit 32 can simultaneously determine the presence or absence of the buried object U and infer the configuration of the buried object U, can infer the configuration of the buried object U without determining the presence or absence of the buried object U, or can determine the presence or absence of the buried object U after inferring the configuration of the buried object U.

[0125] For example, as Figure 10As shown in the left figure, when the difference between the left-side distance DS2L and the right-side distance DS2R of the buried object detection unit 32 is less than the first threshold, the buried object detection unit 32 can infer that the buried object U11 is buried in a manner extending along the left-right direction. This is because, when a buried object U is buried along the left-right direction, the shape of the sand pile on the left side of the center plane CP is likely to become substantially the same as the shape of the sand pile on the right side of the center plane CP. In addition, the left-right direction is the direction parallel to the left-right axis of the excavator 100.

[0126] Or, as Figure 10 shown in the central figure, when the left-side distance DS2L is greater than the right-side distance DS2R and the difference between the left-side distance DS2L and the right-side distance DS2R is equal to or greater than the second threshold, the buried object detection unit 32 can also infer that the buried object U12 is buried in a manner where the left end is closer to the cab 10 (tilted with respect to the front-rear direction) than the right end. This is because, when the buried object U12 is buried as shown in the central figure, the sand pile on the left side of the center plane CP is likely to expand in the front-rear direction, and the sand pile on the right side of the center plane CP is less likely to expand in the front-rear direction. Figure 10 shown in the central figure, when the buried object U12 is buried as shown in the central figure, the sand pile on the left side of the center plane CP is likely to expand in the front-rear direction, and the sand pile on the right side of the center plane CP is less likely to expand in the front-rear direction.

[0127] Or, as Figure 10 shown in the right figure, when the right-side distance DS2R is greater than the left-side distance DS2L and the difference between the left-side distance DS2L and the right-side distance DS2R is equal to or greater than the third threshold, the buried object detection unit 32 can also infer that the buried object U13 is buried in a manner where the right end is closer to the cab 10 (tilted with respect to the front-rear direction) than the left end. This is because, when the buried object U13 is buried as shown in the right figure, the sand pile on the left side of the center plane CP is less likely to expand in the front-rear direction, and the sand pile on the right side of the center plane CP is likely to expand in the front-rear direction. In addition, the first threshold, the second threshold, and the third threshold may be the same value or different values from each other. Figure 10 shown in the right figure, when the buried object U13 is buried as shown in the right figure, the sand pile on the left side of the center plane CP is less likely to expand in the front-rear direction, and the sand pile on the right side of the center plane CP is likely to expand in the front-rear direction. In addition, the first threshold, the second threshold, and the third threshold may be the same value or different values from each other.

[0128] Or, the buried object detection unit 32 can repeatedly calculate the position of the left end of the sand pile and the position of the right end of the sand pile at a prescribed calculation cycle. The position of the left end of the sand pile represents the position of the left edge of the ground raised by excavation, and the position of the right end of the sand pile represents the position of the right edge of the ground raised by excavation. In the illustrated example, the buried object detection unit 32 can calculate the position of the left end of the sand pile and the position of the right end of the sand pile based on the image acquired by the front camera 70F. And, the buried object detection unit 32 repeatedly calculates the left-side width WDL and the right-side width WDR at a prescribed calculation cycle based on the calculated position of the left end of the sand pile and the position of the right end of the sand pile.

[0129] The left width WDL is the distance between the center plane CP of the excavation attachment device AT in the left-right direction and the left end position of the sand pile. The right width WDR is the distance between the center plane CP of the excavation attachment device AT in the left-right direction and the right end position of the sand pile.

[0130] Moreover, when it is inferred that there is a buried object U based on the excavation reaction force or the like, the buried object detection unit 32 can also infer the configuration of the buried object U based on the comparison result between the left width WDL and the right width WDR. In addition, the buried object detection unit 32 can simultaneously determine the presence or absence of the buried object U and infer the configuration of the buried object U, can also infer the configuration of the buried object U without determining the presence or absence of the buried object U, or can determine the presence or absence of the buried object U after inferring the configuration of the buried object U.

[0131] For example, as Figure 10 shown in the left figure of, the buried object detection unit 32 can infer that the buried object U11 is buried in a manner extending along the left-right direction when the difference between the left width WDL and the right width WDR is less than the first threshold. This is because when a buried object U is buried along the left-right direction, the shape of the sand pile on the left side of the center plane CP is likely to become substantially the same as the shape of the sand pile on the right side of the center plane CP.

[0132] Or, as Figure 10 shown in the central figure of, when the left width WDL is greater than the right width WDR and the difference between the left width WDL and the right width WDR is equal to or greater than the second threshold, the buried object detection unit 32 can also infer that the buried object U12 is buried in a manner such that the left end is closer to the cockpit 10 (tilted with respect to the front-rear direction) than the right end. This is because when the buried object U12 is buried as shown in the central figure of Figure 10 the left width WDL is greater than the right width WDR and the difference between the left width WDL and the right width WDR is equal to or greater than the second threshold, the buried object detection unit 32 can also infer that the buried object U12 is buried in a manner such that the left end is closer to the cockpit 10 (tilted with respect to the front-rear direction) than the right end. This is because when the buried object U12 is buried as shown in the central figure of, the sand pile on the left side of the center plane CP is likely to expand to the left, and the sand pile on the right side of the center plane CP is not likely to expand to the right.

[0133] Or, as Figure 10 shown in the right figure of, when the right width WDR is greater than the left width WDL and the difference between the left width WDL and the right width WDR is equal to or greater than the third threshold, the buried object detection unit 32 can also infer that the buried object U13 is buried in a manner such that the right end is closer to the cockpit 10 (tilted with respect to the front-rear direction) than the left end. This is because when the buried object U13 is buried as shown in the right figure of Figure 10 the right figure of, the sand pile on the left side of the center plane CP is not likely to expand to the left, and the sand pile on the right side of the center plane CP is likely to expand to the right. In addition, the first threshold, the second threshold, and the third threshold can be the same value or different values from each other.

[0134] Further, the buried object detection unit 32 may also infer the arrangement of the buried object U based on the comparison result between the left distance DS2L and the right distance DS2R and the comparison result between the left width WDL and the right width WDR.

[0135] Further, the buried object detection unit 32 may infer the arrangement of the buried object U based on information related to the excavation reaction force, or may also infer the arrangement of the buried object U based on information related to the ground lifted by excavation and information related to the excavation reaction force. For example, the buried object detection unit 32 may infer the arrangement of the buried object U based on the excavation reaction force acting in the turning direction calculated by the excavation reaction force calculation unit 31.

[0136] Specifically, when the excavation reaction force acting in the left turning direction is equal to or greater than the left turning threshold value, the buried object detection unit 32 may infer that the buried object U12 is buried in such a manner that the left end is closer to the cab 10 than the right end (tilted with respect to the front-rear direction). This is because, when the buried object U12 is buried as shown in the central figure of Figure 10 the excavation reaction force acting on the right half of the bucket 6 is greater than the excavation reaction force acting on the left half of the bucket 6, and a torque in the direction of the arrow AR1 acts on the bucket 6. In addition, in the illustrated example, the excavation reaction force acting in the left turning direction is the left turning pressure (P17) when the left turning pressure (P17) is greater than the right turning pressure (P18).

[0137] Similarly, when the excavation reaction force acting in the right turning direction is equal to or greater than the right turning threshold value, the buried object detection unit 32 may also infer that the buried object U13 is buried in such a manner that the right end is closer to the cab 10 than the left end (tilted with respect to the front-rear direction). This is because, when the buried object U13 is buried as shown in the central figure of Figure 10 the excavation reaction force acting on the left half of the bucket 6 is greater than the excavation reaction force acting on the right half of the bucket 6, and a torque in the direction of the arrow AR2 acts on the bucket 6. In addition, in the illustrated example, the excavation reaction force acting in the right turning direction is the right turning pressure (P18) when the right turning pressure (P18) is greater than the left turning pressure (P17). Further, the left turning threshold value and the right turning threshold value may be the same value or different values from each other.

[0138] Further, Figure 10An example is shown where there is an embedded object U in the traveling direction of the left half of the bucket 6 and also an embedded object U in the traveling direction of the right half of the bucket 6. However, the embedded object detection unit 32 can also infer, by the same method, that the embedded object U is buried in such a way that there is an embedded object U only in the traveling direction of the left half of the bucket 6 and there is no embedded object U in the traveling direction of the right half of the bucket 6. Further, the embedded object detection unit 32 can also infer, by the same method, that the embedded object U is buried in such a way that there is an embedded object U only in the traveling direction of the right half of the bucket 6 and there is no embedded object U in the traveling direction of the left half of the bucket 6.

[0139] Next, referring to Figure 11 , the control system SYS of the excavator will be described. Figure 11 is a diagram showing a structural example of the control system SYS of the excavator. The information acquired by the excavator 100 can be shared with managers, operators of other excavators, etc. through the control system SYS of the excavator as shown in Figure 11 .

[0140] The control system SYS is a system that controls the excavator 100. In the illustrated example, the control system SYS mainly consists of the excavator 100, the support device 200, and the management device 300. The excavator 100, the support device 200, and the management device 300 are each provided with a communication device and are directly or indirectly connected to each other via a mobile phone communication network, a satellite communication network, or a short-range wireless communication network, etc. The excavator 100, the support device 200, and the management device 300 that make up the control system SYS can each be one or multiple. In the Figure 11 example, the control system SYS includes one excavator 100, one support device 200, and one management device 300.

[0141] Typically, the support device 200 is a mobile terminal device, such as a computer like a notebook PC, a tablet PC, or a smart phone carried by a worker at a construction site, etc. The support device 200 can also be a computer carried by the operator of the excavator 100. However, the support device 200 can also be a fixed terminal device.

[0142] Typically, the management device 300 is a fixed terminal device, such as a server computer installed in a management center outside the construction site, etc. The management device 300 can also be a portable computer (e.g., a mobile terminal device like a notebook PC, a tablet PC, or a smart phone).

[0143] At least one of the support device 200 and the management device 300 may also be provided with a monitor and an operating device for remote operation. At this time, the excavator 100 and at least one of the support device 200 and the management device 300 constitute a remote operation system of the excavator. Moreover, the operator can operate the excavator 100 using the operating device for remote operation. The operating device for remote operation is connected to the controller 30 through a communication network such as a mobile phone communication network, a satellite communication network, or a short-range wireless communication network. The controller 30 may be included in the support device 200 or may be included in the management device 300. Also, all or part of the functions executed by the controller 30 may be executed by the support device 200 or may be executed by the management device 300. Also, the excavator 100 may be an unmanned excavator. At this time, the excavator 100 operates autonomously regardless of the operation of the operation device 26 (including the operation device for remote operation).

[0144] And, in Figure 11 In the example shown, the buried object detection mode switch 76 may be provided in the support device 200 or may be provided in the management device 300. Also, the buried object detection function may be executed by the support device 200 or may be executed by the management device 300.

[0145] As described above, the excavator 100 according to the embodiment of the present invention includes: a lower traveling body 1; an upper revolving body 3 mounted on the lower traveling body 1; a controller 30 mounted on the upper revolving body 3; an excavation attachment AT mounted on the upper revolving body 3; and a detection device that detects information related to at least one of the excavation reaction force when excavating with the excavation attachment AT and the ground heaving due to the excavation. The detection device that detects information related to the excavation reaction force is, for example, an excavation pressure sensor S1. The information related to the excavation reaction force is, for example, an analog value or a digital value indicating a physical quantity used to calculate the excavation reaction force. The detection device that detects information related to the excavation reaction force may include a posture detection device M1. The detection device that detects information related to the heaving ground is, for example, an object detection device 70. The information related to the heaving ground is, for example, the boundary line between the heaving ground and the non-heaving ground, the height of the heaving part, the shape of the heaving part, the volume of the heaving part, or the surface area of the heaving part. The object detection device 70 is, for example, an imaging device such as a monocular camera or LIDAR. The detection device that detects information related to the heaving ground may include at least one of the posture detection device M1 and the excavation pressure sensor S1. Moreover, the excavator 100 is configured to infer the presence or absence of a buried object based on the information detected by the detection device.

[0146] With this structure, the excavator 100 can infer the presence or absence of a buried object during excavation work, so that it is possible to prevent the excavation attachment AT from contacting the buried object and damaging the buried object during excavation work.

[0147] The excavator 100 may be provided with a controller 30 that controls the operation of the excavation attachment AT. At this time, the controller 30 may be configured to control the operation of the excavation attachment AT so as to avoid contact between the buried object and the excavation attachment AT when it is inferred that there is a buried object.

[0148] The controller 30 may be configured to calculate the excavation reaction force when excavating with the excavation attachment AT. At this time, the detection device may be configured to detect information related to the ground that bulges due to excavation. Moreover, the controller 30 may be configured to infer the presence or absence of a buried object based on at least one of the excavation reaction force and the information detected by the detection device.

[0149] With this configuration, even when the operator of the excavator 100 is manually operating to bring the excavation attachment AT close to the buried object, the controller 30 can move the excavation attachment AT away from the buried object or stop the operation of the excavation attachment AT. Therefore, the controller 30 can more reliably prevent the excavation attachment AT from contacting the buried object and damaging the buried object during the excavation work.

[0150] The excavator 100 may be configured to notify the outside of the presence of a buried object when it is inferred that there is a buried object. For example, as Figure 4 shown, when it is inferred that there is a buried object, the buried object detection unit 32 of the controller 30 may output a control command to at least one of the display device 40 and the sound output device 45 to visually or auditorily notify the operator of the excavator 100 that there is a buried object near the tip of the bucket 6.

[0151] With this configuration, the controller 30 can more reliably prevent the excavation attachment AT from contacting the buried object and damaging the buried object during the excavation work.

[0152] The excavator 100 can be configured to infer the presence or absence of buried objects based on at least one of the excavation reaction force calculated when moving a specified part of the excavation attachment device AT along a specified track for excavation and information related to the ground heaving due to the excavation. For example, the buried object detection unit 32 of the controller 30 can be configured to infer the presence or absence of buried objects based on the comparison result between the excavation reaction force calculated by the excavation reaction force calculation unit 31 when the tip of the bucket 6 moves along the target track TP and the excavation reaction force threshold. Alternatively, the buried object detection unit 32 can also be configured to infer the presence or absence of buried objects based on the comparison result between the distance DS2 calculated when the tip of the bucket 6 moves along the target track TP and the distance threshold. Alternatively, the buried object detection unit 32 can also be configured to infer the presence or absence of buried objects based on the comparison result between the excavation reaction force calculated when the tip of the bucket 6 moves along the target track TP and the excavation reaction force threshold and the comparison result between the distance DS2 calculated when the tip of the bucket 6 moves along the target track TP and the distance threshold.

[0153] The excavator 100 can be configured to infer the presence or absence of buried objects based on at least one of the excavation reaction force when moving the bucket 6 that constitutes the excavation attachment device AT in the direction closer to the upper swing body 3 for excavation and information related to the ground heaving due to the excavation. For example, as Figure 5 shown, the buried object detection unit 32 of the controller 30 can be configured to infer the presence of a buried object when the excavation reaction force F calculated when the tip of the bucket 6 moves along the target track TP toward the machine body side is greater than a specified excavation reaction force threshold Ft (refer to Figure 6 .). Alternatively, as Figure 9 shown, the buried object detection unit 32 can also be configured to infer the presence of a buried object when the distance DS2 calculated when the tip of the bucket 6 moves toward the machine body side is less than the distance threshold. Alternatively, the buried object detection unit 32 can further be configured to infer the presence of a buried object when the excavation reaction force F calculated when the tip of the bucket 6 moves along the target track TP toward the machine body side is greater than the excavation reaction force threshold Ft and when the distance DS2 calculated when the tip of the bucket 6 moves toward the machine body side is less than the distance threshold.

[0154] With this structure, the excavator 100 can accurately infer the presence or absence of buried objects, and thus can more reliably prevent the excavation attachment device AT from coming into contact with buried objects and damaging the buried objects during excavation work.

[0155] Further, in the above-described embodiment, the buried object detection unit 32 is configured to infer the presence or absence of a buried object based on the excavation reaction force calculated by the excavation reaction force calculation unit 31 when the tip of the bucket 6 moves along the target track TP. However, the buried object detection unit 32 may also be configured to infer the presence or absence of a buried object based on the excavation reaction force calculated by the excavation reaction force calculation unit 31 when the tip of the bucket 6 moves regardless of a prescribed track such as the target track TP.

[0156] Further, as Figure 1 shown, the excavator 100 according to the embodiment of the present invention includes: a lower traveling body 1; an upper swing body 3 mounted on the lower traveling body 1; an excavation attachment AT mounted on the upper swing body 3; and a detection device that detects information related to at least one of the excavation reaction force during excavation by the excavation attachment AT and the ground heaving due to excavation. The detection device that detects information related to the excavation reaction force is, for example, an excavation pressure sensor S1. The detection device that detects information related to the excavation reaction force may include an attitude detection device M1. The detection device that detects information related to the heaving ground is, for example, an object detection device 70. The object detection device 70 is, for example, an imaging device such as a monocular camera or LIDAR. Moreover, the excavator 100 is configured to infer the configuration of the buried object U based on the information detected by the detection device.

[0157] With this configuration, the excavator 100 can infer the configuration of the buried object U during the excavation work, and thus can prevent the excavation attachment AT from contacting the buried object U and damaging the buried object U during the excavation work.

[0158] Further, as Figure 10 shown, the information related to the ground heaving due to excavation may include information related to the range of the portion of the sand pile formed by the ground heaving due to excavation that is located on the left side of the center plane CP of the excavation attachment AT extending in the front-rear direction and information related to the range of the portion of the sand pile that is located on the right side of the center plane CP.

[0159] Further, the information related to the excavation reaction force during excavation by the excavation attachment AT may include information related to the excavation reaction force acting in the swing direction.

[0160] Based on these structures, the excavator 100 can more accurately infer the configuration of the buried object U buried underground. For example, the excavator 100 can infer whether the buried object U is buried obliquely with respect to the front-rear direction. Or, the excavator 100 can infer that the distance between the left end of the bucket 6 and the buried object U in the front-rear direction is larger or smaller than the distance between the right end of the bucket 6 and the buried object U in the front-rear direction. Or, the excavator 100 can infer that there is a buried object U in the traveling direction of the left half of the bucket 6, but there is no buried object in the traveling direction of the right half of the bucket 6.

[0161] As described above, the preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments, and various modifications and substitutions can be made to the above embodiments without departing from the scope of the present invention.

Claims

1. A control device for an excavator, the excavator having a detection device for detecting information related to ground surface raised by excavation, wherein: The control device of the shovel estimates the presence or absence of a buried object based on at least one of an excavation reaction force calculated when excavation is performed by an excavation attachment of the shovel and information detected by the detection device.

2. The control device for an excavator according to claim 1, wherein: When it is inferred that there is a buried object, the operation of the excavation attachment is controlled so as to avoid contact between the buried object and the excavation attachment.

3. The control device for an excavator according to claim 1, wherein: When it is estimated that a buried object exists, the existence of the buried object is notified to the outside.

4. The control device for an excavator according to claim 1, wherein: The presence or absence of buried objects is estimated based on at least one of an excavation reaction force calculated when excavation is performed by moving a predetermined portion of the excavation attachment along a predetermined track and information on ground surface that is raised by excavation.

5. The control device for an excavator according to claim 1, wherein: The presence or absence of buried objects is estimated based on at least one of an excavation reaction force when excavation is performed by moving a bucket constituting the excavation attachment in a direction approaching a body of the excavator and information on ground surface rising due to excavation.

6. A control device for an excavator, the excavator having a detection device for detecting information related to ground surface raised by excavation, wherein: The control device of the shovel estimates the arrangement of the buried object based on at least one of an excavation reaction force when excavating is performed by an excavation attachment of the shovel and information detected by the detection device.

7. The control device for an excavator according to claim 6, wherein: The information about the ground rising due to excavation includes information about the range of a portion of a pile of sand and soil formed by the ground rising due to excavation located to the left of a center plane of the excavation attachment extending in the front-rear direction and information about the range of a portion of the pile of sand and soil located to the right of the center plane.

8. The control device for an excavator according to claim 6, wherein: The excavation reaction force when excavating is performed by the excavation attachment includes an excavation reaction force acting in the swing direction.

9. An excavator, comprising: The control device according to any one of claims 1 to 8; Lower walking body; an upper rotating body mounted on the lower walking body; and The excavation attachment is mounted on the upper rotating body.

Images