JP2024055125A - Work Machine - Google Patents

Abstract

[Problem] To provide a work machine capable of suppressing the occurrence of depressions in the roadway for transport vehicles after excavation and suppressing the time required for leveling work. [Solution] The work machine includes a work device for excavating an excavation target object and discharging the soil at a predetermined soil discharge position, and a control device for controlling the work device to move on a predetermined excavation target surface of the excavation target object and within an area above it, and further includes an external environment recognition device for recognizing the surrounding environment, and the control device measures a bench height, which is the height from a design surface that defines the target shape of the excavation target object after excavation to the top surface of the excavation target object on which the work machine is riding, based on the recognition result of the external environment recognition device, and sets the excavation target surface to be higher than the design surface based on the bench height and information on the site environment acquired in advance. [Selected Figure] Figure 6

Description

The present invention relates to a work machine.

One known technology relating to a work machine that automatically performs various tasks is described in, for example, Patent Document 1. Patent Document 1 describes a work support system for a self-propelled work machine, which determines an area in which an estimated excavation volume can be obtained from an excavation target by one excavation operation of the work machine as an excavation area based on an estimated excavation volume by one excavation operation of the work machine, calculates the work position of the work machine when performing the next excavation operation based on the excavation area, and displays information about the work position on a display device.

JP 2017-14726 A

In the above-mentioned conventional technology, when a work machine performs an excavation operation by extending the front working implement downward from the edge of the top surface of the excavation target above the excavation target, in order to maintain the excavation amount in relation to the change in the height direction of the excavation target by changing the distance from the top surface of the excavation target to the travel path, the height of the excavation target (the distance from the top surface of the excavation target to the travel path) is set as the excavation height (limiting height) and the attitude of the front working implement of the work machine is guided.

However, when the excavation height is fixed to the height of the object to be excavated, there is almost no height margin when leveling the travel path, and errors may occur with respect to the design value of the travel path. For example, depressions may occur in the design value of the travel path, in which case filling work is necessary, which increases the time required for leveling work. Specifically, when a travel path with no margin from the design value is set, large depressions such as scraping and sinking caused by dump truck travel will occur, and it will be necessary to fill them in the leveling work. In some cases, it may be necessary to temporarily suspend work by the work machine. In addition, it is possible that a transport vehicle will become stuck if a depression occurs in the travel path.

The present invention has been made in consideration of the above, and aims to provide a work machine that can prevent the occurrence of depressions in the roadway for transport vehicles after excavation, and can reduce the time required for leveling work.

The present application includes multiple means for solving the above problems, and one example is a work machine equipped with a working device for excavating an excavation target object and discharging the soil at a predetermined soil discharge position, and a control device for controlling the working device to move on a predetermined excavation target surface for the excavation target object and within an area above the surface, further comprising an external environment recognition device for recognizing the surrounding environment, and the control device measures a bench height, which is the height from a design surface that determines the target shape of the excavation target object after excavation to the top surface of the excavation target object on which the work machine is mounted, based on the recognition results of the external environment recognition device, and sets the excavation target surface to be higher than the design surface based on the bench height and information related to the site environment obtained in advance.

The present invention can prevent the occurrence of depressions in the roadway for transport vehicles after excavation, thereby preventing the occurrence of transport vehicles getting stuck and the time required for leveling work to backfill depressions.

1 is a diagram showing a schematic external view of a hydraulic excavator, which is an example of a work machine. FIG. 2 is a side view showing a schematic view of a hydraulic excavator and its surroundings at a work site. FIG. 2 is a diagram illustrating a controller of the hydraulic excavator together with a hydraulic drive unit. FIG. 3 is a diagram showing details of a solenoid valve unit in FIG. 2 . FIG. 2 is a hardware configuration diagram showing an overview of the control system. FIG. 4 is a functional block diagram showing the processing contents of a controller. 10 is a flowchart showing the contents of a bench height measurement process in a bench height measurement unit. 10 is a flowchart showing the contents of a dump load measurement process in a dump load measurement unit. 13 is a flowchart showing the contents of a target height gradient calculation process in a target height gradient calculation unit. FIG. 13 is a diagram showing an example of a map used in a target height gradient calculation unit. 10 is a flowchart showing the contents of a target height calculation process in a target height calculation unit. FIG. 13 is a diagram showing an example of a map used in a target height calculation unit. FIG. 11 is a functional block diagram showing the processing contents of a controller according to a second embodiment. 10 is a flowchart showing the contents of a dump truck wheel height measurement process in a dump truck wheel height measurement unit. 13 is a flowchart showing the contents of a target height gradient calculation process in a target height gradient calculation unit. 13 is a flowchart showing the contents of a target height calculation process in a target height calculation unit. FIG. 13 is a diagram showing an example of a map used in a target height calculation unit.

The following describes an embodiment of the present invention with reference to the drawings. In this embodiment, a hydraulic excavator with a bucket as a working tool at the tip of the working device is used as an example of a working machine, but the present invention can also be applied to other working machines as long as they have a multi-joint working device that is configured by connecting multiple link members (attachments, arms, booms, etc.).

In addition, in the following description, when there are multiple identical components, an alphabet may be added to the end of the reference symbol (number), but the alphabet may be omitted to refer to the multiple components collectively. For example, when there are one traveling hydraulic motor 4a and one traveling hydraulic motor 4b on the left and one on the right, these may be collectively referred to as traveling hydraulic motor 4.

First Embodiment
A first embodiment of the present invention will be described with reference to FIGS.

Figure 1 is a diagram showing the appearance of a hydraulic excavator, which is an example of a work machine according to this embodiment, and Figure 2 is a side view showing the hydraulic excavator and its surroundings at a work site. Figure 3 is a diagram showing the controller of the hydraulic excavator together with the hydraulic drive system, and Figure 4 is a diagram showing the details of the solenoid valve unit in Figure 2.

In FIG. 1, the hydraulic excavator 1 is composed of an articulated work front 2 and a traveling body 3. The traveling body 3 is composed of a lower traveling section 3a that travels using a pair of left and right traveling hydraulic motors 4b (4a), and an upper rotating section 3b that is attached to the lower traveling section 3a and rotates using a rotating hydraulic motor 5. Note that in FIG. 1, only one of the pair of left and right traveling hydraulic motors 4b is shown, and the other traveling hydraulic motor 4a is indicated by a reference number in parentheses.

The work front 2 (working device) is a multi-jointed working device configured by connecting multiple driven members (boom 6, arm 7, and bucket 8) that each rotate vertically. The base end of the boom 6 is rotatably supported via a boom pin at the front of the upper rotating section 3b. The arm 7 is rotatably connected to the tip of the boom 6 via an arm pin, and the bucket 8 is rotatably connected to the tip of the arm 7 via a bucket pin. The boom 6 is driven by a boom cylinder 61, the arm 7 is driven by an arm cylinder 71, and the bucket 8 is driven by a bucket cylinder 81.

To enable measurement of the rotation of the boom 6, arm 7, and bucket 8, a boom angle sensor 62 is attached to the boom pin, an arm angle sensor 72 is attached to the arm pin, and a bucket angle sensor 82 is attached to the bucket link 9, and a vehicle tilt angle sensor 31 is attached to the upper rotating part 3b to detect the tilt angle of the upper rotating part 3b relative to a reference plane (e.g., a horizontal plane). Note that the angle sensors 62, 72, and 82 can each be replaced with an angle sensor relative to a reference plane (e.g., a horizontal plane).

A rotation angle sensor 32 is attached to the central axis of rotation so that the relative angle between the upper rotating part 3b and the lower running part 3a can be measured.

An operating device 10 for operating the hydraulic excavator is installed in the cab 13 provided in the upper rotating part 3b. The operating device 10 is composed of a right operating lever 10a for operating the boom cylinder 61 (boom 6) and the bucket cylinder 81 (bucket 8), a left operating lever 10b for operating the arm cylinder 71 (arm 7) and the swing hydraulic motor 5 (upper rotating part 3b), a right operating lever 10c for operating the right traveling hydraulic motor 4a (lower traveling part 3a), and a left operating lever 10d for operating the left traveling hydraulic motor 4b (lower traveling part 3a). In the following, the right operating lever 10a, the left operating lever 10b, the right traveling lever 10c, and the left traveling lever 10d may be collectively referred to as the operating device 10.

As shown in FIG. 2, an external environment recognition device 610 (described later) is provided for acquiring information about the surroundings of the hydraulic excavator 1. The external environment recognition device 610 is, for example, a LiDAR (Light Detection and Ranging) or a camera (including a stereo camera, etc.), and can acquire topographical information about the surroundings of the hydraulic excavator 1 and information about other work machines (including transport vehicles).

The upper rotating section 3b is equipped with an engine 11, which is a prime mover. As shown in FIG. 3, the engine 11 drives hydraulic pumps 20a, 20b and a pilot pump 30. The hydraulic pumps 20a, 20b are variable displacement pumps whose displacements are controlled by regulators 20aa, 20ba, and the pilot pump 30 is a fixed displacement pump. The hydraulic pump 20 and the pilot pump 30 draw hydraulic oil from a tank 200. In this embodiment, a control signal output from a controller 40 is input to the regulators 20aa, 20ba. Although detailed configurations of the regulators 20aa, 20ba are omitted, the discharge flow rates of the hydraulic pumps 20a, 20b are controlled in response to the control signal.

The pump line 148a, which is the discharge pipe of the pilot pump 30, passes through the lock valve 39 and is then connected to each solenoid valve in the solenoid valve unit 160. The lock valve 39 is, for example, an electromagnetic switching valve, and its electromagnetic drive unit is electrically connected to a gate lock lever position detector 12 arranged in the driver's cab 13. The position of the gate lock lever is detected by the position detector 12, and a signal corresponding to the position of the gate lock lever is input from the position detector 12 to the lock valve 39. If the gate lock lever is in the locked position, the lock valve 39 closes and the pump line 148a is cut off, and if it is in the unlocked position, the lock valve 39 opens and the pump line 148a is opened. In other words, when the pump line 148a is cut off, operation by the operating device 10 is disabled, and operations such as traveling, turning, and excavation are prohibited.

The operating device 10 is an electric lever type that generates an electric signal according to the amount and direction of operation by the operator. The electric signal thus generated is input to the controller 40, and the controller 40 outputs an electric signal to the solenoid valve unit 160 to drive the solenoid proportional valves 54, 55, 56, 57, 58, and 59 according to the operation input to the operating device 10. The proportional solenoid valves 54, 55, 56, 57, 58, and 59 are supplied to the hydraulic actuators 150a, 150b, 151a, 151b, 152a, 152b, 153a, 153b, 154a, 154b, 155a, and 155b (hereinafter, hydraulic actuators 150a and 155b) of the corresponding flow control valves 15a, 15b, 15c, 15d, 15e, and 15f in response to the input electrical signals via pilot lines 144a, 144b, 145a, 145b, 146a, 146b, 147a, 147b, 148a, 148b, 149a, and 149b, and are used as control signals to drive the flow control valves 15a, 15b, 15c, 15d, 15e, and 15f.

The pressure oil discharged from the hydraulic pump 20 is supplied to the right traveling hydraulic motor 4a, the left traveling hydraulic motor 4b, the swing hydraulic motor 5, the boom cylinder 61, the arm cylinder 71, and the bucket cylinder 81 via the flow control valves 15a, 15b, 15c, 15d, 15e, and 15f. The supplied pressure oil causes the boom cylinder 61, the arm cylinder 71, and the bucket cylinder 81 to expand and contract, causing the boom 6, the arm 7, and the bucket 8 to rotate, and the position and attitude of the bucket 8 to change. In addition, the supplied pressure oil causes the swing hydraulic motor 5 to rotate, causing the upper swing part 3b to swing relative to the lower traveling part 3a. The supplied pressure oil causes the right traveling hydraulic motor 4a and the left traveling hydraulic motor 4b to rotate, causing the lower traveling part 3a to travel.

The boom cylinder 61, arm cylinder 71, and bucket cylinder 81 are provided with load detection devices 16a, 16b, 16c, 16e, and 16f so that their cylinder pressures can be detected. The load detection device 16 is, for example, a pressure sensor that detects the pressure on the bottom side and the pressure on the rod side of each of the boom cylinder 61, arm cylinder 71, and bucket cylinder 81, and outputs the pressure as an electrical signal to the controller 40.

As shown in FIG. 4, the front control hydraulic unit 160 includes solenoid proportional valves 54a, 54b, 55a, 55b, 56a, and 56b whose primary port side is connected to the pilot pump 30 via pump line 148a and which reduce the pilot pressure from the pilot pump 30 and output it to pilot lines 144a, 144b, 145a, 145b, 146a, and 146b, and solenoid proportional valves 57a, 57b, 58a, 58b, 59a, and 59b (see FIG. 3) which similarly reduce the pilot pressure from the pilot pump 30 and output it to pilot lines 147a, 147b, 148a, 148b, 149a, and 149b.

The electromagnetic proportional valves 54a, 54b, 55a, 55b, 56a, 56b, 57a, 57b, 58a, 58b, 59a, 59b are at a minimum opening when not energized, and the opening increases as the current, which is the control signal from the controller 40, increases. In this way, the opening of each electromagnetic proportional valve 54a, 54b, 55a, 55b, 56a, 56b, 57a, 57b, 58a, 58b, 59a, 59b corresponds to the control signal from the controller 40.

In the control hydraulic unit 160 configured as described above, when a control signal is output from the controller 40 to drive the electromagnetic proportional valves 54a, 54b, 55a, 55b, 56a, 56b, 57a, 57b, 58a, 58b, 59a, 59b, pilot pressure can be generated even when the corresponding operating device 10 is not operated by an operator, so that the operation of each actuator 4, 5, 61, 71, 81 can be forcibly generated.

Figure 5 is a hardware configuration diagram showing an overview of the control system.

In FIG. 5, the control system includes a posture detection device 50, an operation device 10, a display device (e.g., a liquid crystal display) 53 installed in the cab 13 and capable of displaying the current operation mode for the operation modes described below, an input device (e.g., a touch panel display) installed in the cab 13 for inputting changes to the operation mode described below, a load detection device 16 which is a pressure sensor provided on the boom cylinder 61, arm cylinder 71, and bucket cylinder 81, and a controller (control device) 40 which is a computer that manages control.

The posture detection device 50 is composed of a vehicle body inclination angle sensor 31, a rotation angle sensor 32, a boom angle sensor 62, an arm angle sensor 72, and a bucket angle sensor 82. These angle sensors 32, 62, 72, and 82 function as posture sensors for the work front 2.

The controller 40 has an input interface unit 91, a central processing unit (CPU) 92 which is a processor, a read-only memory (ROM) 93 and a random access memory (RAM) 94 which are storage devices, and an output interface unit 95. The input interface unit 91 inputs signals from the angle sensors 32, 62, 72, 82 and the tilt angle sensor 31 which are the attitude detection device 50, a signal indicating the amount of operation from the operation device 10, signals from the pressure sensors 16a, 16b, 16c, 16d, 16e, 16f of the load detection device 16 provided on each cylinder 61, 71, 81 which is the load detection device 16, a signal from the communication device 600 which acquires information on transport vehicles such as dump trucks from the control center, and a signal from the external environment recognition device 610 which acquires information on the surrounding environment of the work machine, and converts them so that the CPU 92 can perform calculations. The ROM 93 is a recording medium that stores a control program for executing the control contents including the processing related to the flowchart described later, and various information required for executing the flowchart, and the CPU 92 performs a predetermined calculation process on the signals taken in from the input unit 91 and memories 93 and 94 according to the control program stored in the ROM 93. The output interface unit 95 creates an output signal according to the calculation result in the CPU 92, and outputs the signal to the solenoid proportional valves 54, 55, 56, 57, 58, 59 or the display device 53 to drive and control the hydraulic actuators 4, 5, 61, 71, 81, or display a guidance operation for estimating parameters described later on the screen of the display device 53.

Note that the controller 40 in FIG. 4 includes semiconductor memories ROM 93 and RAM 94 as storage devices, but any other storage device may be substituted, and may include, for example, a magnetic storage device such as a hard disk drive.

Figure 6 is a functional block diagram showing the processing contents of the controller.

In FIG. 6, the controller 40 includes an electromagnetic proportional valve control unit 41, a display control unit 42, an automatic driving control unit 43, and a target height calculation unit 400.

The solenoid proportional valve control unit 41 outputs control commands to the solenoid proportional valves 54, 55, 56, 57, 58, and 59 in response to signals output from the automatic operation control unit 43.

The display control unit 42 is a part that controls the display device 53 according to the excavation surface output from the target height calculation unit 400. The display control unit 42 is equipped with a display ROM in which a large amount of display-related data including images and icons of the hydraulic excavator 1 is stored, and the display control unit 42 reads out a predetermined program based on a flag included in the input information and controls the display on the display device 53.

The automatic driving control unit 43 outputs the calculation result to the solenoid proportional valve control unit 41 based on the posture information of the work front 2 output from the posture detection device 50 and the signal output from the target height calculation unit 404. For example, it calculates the movement amount of the boom cylinder 61, arm cylinder 71, and bucket cylinder 81 for rotating the boom 6, arm 7, and bucket 8, respectively, to align the bucket toe height with the excavation surface indicating the bucket toe height range of the excavation target, and outputs the calculation result to the solenoid proportional valve control unit 41. However, the specific configuration of the automatic driving control unit 43 is not limited to this, and may be realized by other means.

The target height calculation unit 400 includes a bench height measurement unit 401, a dump load measurement unit 402, a target height gradient calculation unit 403, and a target height calculation unit 404.

The bench height measuring unit 401 calculates the bench height based on input from the external environment recognition device 610. The calculated bench height is output to the target height calculation unit 404. For example, from the signal from the external environment recognition device 610, the top surface of the excavation target on which the work machine rests during excavation work, the downward sloping excavation target surface that connects to the top surface of the excavation target, and the end point where the slope of the excavation target surface ends are detected, and the vertical distance between the top surface of the excavation target and the end point is measured as the bench height. However, the specific configuration of the bench height measuring unit 401 is not limited to this, and may be realized by other means.

The dump load measurement unit 402 measures the maximum dump load based on input from the external environment recognition device 610 or the communication device 600. The measured maximum dump load is output to the target height calculation unit 404. For example, the dump tray size of the loading target is detected from the signal from the external environment recognition device 610, the dump size is estimated, and the maximum dump load is measured. Alternatively, dump information of the loading target is obtained from the signal from the communication device 600, and the maximum dump load is measured. However, the specific configuration of the dump load measurement unit 402 is not limited to this, and may be realized by other means.

The target height gradient calculation unit 403 calculates the gradient based on the input from the attitude detection device 50. The calculated gradient is output to the target height calculation unit 404. For example, the bucket toe position is calculated from the signal from the attitude detection device 50, and the bucket toe position where the distance from the center of rotation of the work machine to the bucket toe position is equal to or greater than a predetermined value is set as the reference position. The gradient is calculated to increase according to the distance by which the bucket toe position approaches the center of rotation from the reference position. However, the specific configuration of the target height gradient calculation unit 403 is not limited to this, and may be realized by other means.

The target height calculation unit 404 calculates the excavation surface based on inputs from the bench height measurement unit 401, the dump load measurement unit 402, and the target height gradient calculation unit 403. The calculated excavation surface is output to the automatic driving control unit 43. For example, the target height is calculated by subtracting a height margin for the maximum dump load of the dump load measurement unit 402 from the bench height of the bench height measurement unit 401. The bucket tip range is calculated by multiplying the calculated target height by a gradient according to the bucket tip distance of the target height gradient calculation unit 403, and is output as the target excavation surface. However, the specific configuration of the target height calculation unit 404 is not limited to this, and may be realized by other means.

Figure 7 is a flowchart showing the contents of the bench height measurement process in the bench height measurement unit.

The processing of the flowchart shown in FIG. 7 is performed by inputting information from the external environment recognition device 610.

The bench height measurement unit 401 first detects an input signal from the external environment recognition device 610 (step S100), and then detects from the detected signal the top surface of the excavation target on which the work machine rests during excavation work, the downward sloping excavation target surface that connects to the top surface of the excavation target, and the end point where the slope of the excavation target surface ends (step S110).

Next, the difference in vertical distance between the top surface of the excavation object and the end point is calculated, and the difference in distance is output as the bench height (step S120), and the process ends.

Figure 8 is a flowchart showing the contents of the dump load measurement process in the dump load measurement unit.

The processing of the flowchart shown in FIG. 8 is performed by inputting information from the external environment recognition device 610 or the communication device 600.

The dump truck load measurement unit 402 first detects an input signal from the external environment recognition device 610 or the communication device 600 (step S200), and determines whether the detected input signal is a signal from the external environment recognition device 610 (step S210).

If the determination result in step S210 is YES, the dump truck size is detected from the recognition result based on the input signal from the external environment recognition device 610 (step S221), the maximum dump truck load is calculated from the acquired dump truck size, and this is output as the maximum dump truck load (step S230), and the process ends.

Also, if the determination result in step S210 is NO, the dump size is obtained from the dump information based on the input signal from the detected communication device 600 (step S220), the maximum load capacity of the dump is calculated from the obtained dump size, and this is output as the maximum load capacity of the dump (step S230), and the process ends.

Figure 9 is a flowchart showing the contents of the target height gradient calculation process in the target height gradient calculation unit.

The processing of the flowchart shown in FIG. 9 is performed by inputting information from the posture detection device 50.

The target height gradient calculation unit 403 first detects the input signal from the attitude detection device 50 (step S300) and calculates the position of the bucket tip from the detected signal (step S310).

Next, it is determined whether the bucket tip position calculated in step S310 is greater than a predetermined value (e.g., 15 m forward) (step S320), and if the determination result is YES, a numerical value without gradient is output (step S330), and the process ends.

If the determination result in step S320 is NO, the gradient value according to the distance by which the bucket tip position approaches the turning center is output (step S331), and the process ends.

Figure 10 shows an example of a map used by the target height gradient calculation unit.

In FIG. 10, the map shows the relationship between the distance from the shovel and the height margin, and in the processing in the target height gradient calculation unit 403 (see step S331), the height margin (numerical value of the gradient) is calculated according to the distance from the shovel in accordance with the map.

Figure 11 is a flowchart showing the contents of the target height calculation process in the target height calculation unit.

The processing of the flowchart shown in FIG. 11 is performed by inputting information from the bench height measurement unit 401, the dump truck load measurement unit 402, and the target height gradient calculation unit 403.

The target height calculation unit 404 first detects input signals from the bench height measurement unit 401, the dump load measurement unit 402, and the target height gradient calculation unit 403 (step S400), calculates the target height by subtracting the height corresponding to the maximum dump load from the bench height based on the detected signals from the bench height measurement unit 401 and the dump load measurement unit 402 (step S410), calculates the bucket toe range from the gradient of the target height gradient calculation unit 403 detected in step S400 and the target height calculated in step S410, outputs the calculated bucket toe range as the target excavation surface (step S420), and ends the process.

Figure 12 shows an example of a map used by the target height calculation unit.

In FIG. 12, the map shows the relationship between the maximum load capacity of the dump truck and the height margin, and in the processing in the target height calculation unit 404 (see step S410), the height margin (subtraction amount) is calculated from the maximum load capacity of the dump truck according to the map.

In this embodiment configured as described above, automatic excavation work can be performed along a target excavation surface that ensures the leveling of the excavation work marks. Furthermore, even if depressions occur in the marks left by the automatic excavation work, there is a margin of soil for the leveling work to fill them in, so the leveling work time can be reduced. Even if scraping or sinking occurs due to dump truck travel, there is a margin of soil for the leveling work to fill them in, so the leveling work time can be reduced. Furthermore, because the excavation work marks have a slope, depending on the direction in which the dump truck is stopped, it can be diverted to a travel path where the dump truck will not get stuck without leveling work, so the leveling work time can be reduced.

Second Embodiment
A second embodiment of the present invention will be described with reference to FIGS.

In this embodiment, processing is performed using dump information obtained via a communication device. Note that in this embodiment, the same components and functions as in the first embodiment are given the same reference numerals, and descriptions are omitted as appropriate.

Figure 13 is a functional block diagram showing the processing contents of the controller in this embodiment.

In FIG. 13, the target height calculation unit 400A of the controller 40A has a bench height measurement unit 401, a dump truck wheel height measurement unit 402A, a target height gradient calculation unit 403A, and a target height calculation unit 404A.

The dump truck rut height measurement unit 402A measures the rut height of the dump truck based on input from the external environment recognition device 610. The measured dump truck rut height is output to the target height calculation unit 404A. For example, the dump truck rut height measurement unit 402A detects the road and ruts of the dump truck to be loaded from the signal of the external environment recognition device 610 and measures the rut height relative to the road. However, the specific configuration of the dump truck rut height measurement unit 402A is not limited to this and may be realized by other means.

The target height gradient calculation unit 403A calculates the gradient based on input from the external environment recognition device 610 or the communication device 600. The calculated gradient is output to the target height calculation unit 404A. For example, an approaching dump truck is detected from a signal from the external environment recognition device 610, the direction of travel is estimated, and the dump truck travel direction is obtained. A gradient is calculated according to the distance away from the work machine in the obtained dump truck travel direction. Alternatively, travel path information of the dump truck to be loaded is obtained from a signal from the communication device 600, and the dump truck travel direction is obtained. A gradient is calculated to decrease according to the distance away from the work machine in the obtained dump truck travel direction. However, the specific configuration of the target height gradient calculation unit 403A is not limited to this, and may be realized by other means.

The target height calculation unit 404A calculates the excavation surface based on inputs from the bench height measurement unit 401, the dump truck rut height measurement unit 402A, and the target height gradient calculation unit 403A. The calculated excavation surface is output to the automatic driving control unit 43. For example, the target height is calculated by subtracting a height margin for the dump truck rut height measured by the dump truck rut height measurement unit 402A from the bench height measured by the bench height measurement unit 401. The bucket toe range is calculated by multiplying the calculated target height by the gradient in the dump truck travel direction measured by the target height gradient calculation unit 403A, and is output as the target excavation surface. However, the specific configuration of the target height calculation unit 404A is not limited to this, and may be realized by other means.

Figure 14 is a flowchart showing the contents of the dump truck wheel height measurement process in the dump truck wheel height measurement unit.

The processing of the flowchart shown in FIG. 14 is performed by inputting information from the external environment recognition device 610.

The dump truck rut height measurement unit 402A first detects an input signal from the external environment recognition device 610 (step S500), detects the driving path and ruts of the dump truck to be loaded from the detected signal (step S510), calculates the height of the ruts relative to the driving path from the detected driving path and ruts of the dump truck to be loaded, outputs the dump truck rut height (step S520), and ends the process.

Figure 15 is a flowchart showing the contents of the target height gradient calculation process in the target height gradient calculation unit.

The processing of the flowchart shown in FIG. 15 is performed by inputting information from the external environment recognition device 610 or the communication device 600.

The target height gradient calculation unit 403A first detects an input signal from the external environment recognition device 610 or the communication device 600 (step S600), and determines whether the detected input signal is a signal from the external environment recognition device 610 (step S610).

If the determination result in step S610 is YES, the dump truck travel direction is detected from the recognition result based on the input signal from the external environment recognition device 610 detected in step S600 (step S621), and the gradient is calculated to decrease according to the distance away from the work machine with respect to the acquired dump truck travel direction, and this is output as the maximum dump truck load (step S630), and the process ends.

If the determination result in step S610 is NO, the dump truck travel direction is obtained from the dump truck information based on the input signal from the communication device 600 detected in step S600 (step S620), and the gradient is calculated to decrease according to the distance away from the work machine with respect to the obtained dump truck travel direction, and this is output as the maximum dump truck load (step S630), and the process ends.

Figure 16 is a flowchart showing the contents of the target height calculation process in the target height calculation unit.

The processing of the flowchart shown in FIG. 16 is performed by inputting information from the bench height measurement unit 401, the dump truck wheel height measurement unit 402A, and the target height gradient calculation unit 403A.

The target height calculation unit 404A first detects input signals from the bench height measurement unit 401, the dump truck rut height measurement unit 402A, and the target height gradient calculation unit 403A (step S700), calculates the target height by subtracting the dump truck rut height from the bench height based on the detected signals from the bench height measurement unit 401 and the dump truck rut height measurement unit 402A (step S710), calculates the bucket toe range from the gradient from the target height gradient calculation unit 403A detected in step S700 and the target height calculated in step S710, outputs the calculated bucket toe range as the target excavation surface (step S720), and ends the process.

Figure 17 shows an example of a map used by the target height calculation unit.

In FIG. 17, the map shows the relationship between the rut height of the dump truck and the height margin, and in the processing of the target height calculation unit 404A (see step S710), the height margin (subtraction amount) is calculated from the rut height of the dump truck according to the map.

The rest of the configuration is the same as in the first embodiment.

The present embodiment, configured as described above, can achieve the same effects as the first embodiment.

Even if the surrounding environment changes due to weather, etc., automatic excavation work can be performed along a target excavation surface that ensures the leveling of the excavation work site. Even if significant erosion or sinking occurs due to dump truck driving in rainy weather, the soil margin for filling and leveling work can be adjusted, so the leveling work time can be reduced. Furthermore, by giving a slope to the excavation work site according to the direction in which the dump truck is stopped, it can be converted into a driving road where the dump truck will not get stuck without leveling work, so the leveling work time can be reduced.

<Additional Notes>
The present invention is not limited to the above-described embodiment, but includes various modifications and combinations within the scope of the invention.

For example, in the above embodiment, angle sensors are used to detect the angles of the boom 6, arm 7, and bucket 8, but it is also possible to calculate the posture information of the shovel using a cylinder stroke sensor instead of an angle sensor. Also, while an example has been described in which the operating device 10 is an electric lever type shovel, if the shovel is a hydraulic pilot type shovel, it may be configured to control the command pilot pressure generated by the hydraulic pilot.

The present invention is not limited to having all of the configurations described in the above embodiments, but also includes configurations in which some of the configurations are omitted. Each of the above configurations, functions, etc. may be realized in part or in whole by designing, for example, an integrated circuit. Each of the above configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function.

1...hydraulic excavator, 2...work front, 3a...lower traveling section, 3b...upper slewing section, 4...travel hydraulic motor, 5...slewing hydraulic motor, 6...boom, 7...arm, 8...bucket, 9...bucket link, 10...operating device, 11...engine, 12...position detector, 13...operator's cab, 20...hydraulic pump, 31...vehicle body inclination angle sensor, 32...slewing angle sensor, 39...lock valve, 40, 40A...controller (control device), 41...electromagnetic proportional valve control section, 42...display control section, 43...automatic driving control section, 50...posture detection device, 53...display device, 54, ..., 59...electromagnetic proportional valve, 61... Boom cylinder, 62...boom angle sensor, 71...arm cylinder, 72...arm angle sensor, 81...bucket cylinder, 82...bucket angle sensor, 91...input unit, 91...input interface unit, 92...central processing unit (CPU), 93, 94...memory, 95...output interface unit, 400, 400A...target height calculation unit, 401...bench height measurement unit, 402...dump truck load measurement unit, 402A...dump truck rut height measurement unit, 403, 403A...target height gradient calculation unit, 404, 404A...target height calculation unit, 600...communication device, 610...external environment recognition device

Claims (8)

A working device for excavating the excavation target and discharging the soil at a predetermined soil discharging position;
A control device that controls the working device to move on a predetermined excavation target surface of the excavation target object and within an area above the surface.
Further comprising an external environment recognition device that recognizes the surrounding environment;
The control device includes:
Based on the recognition result of the external environment recognition device, a bench height is measured, which is the height from a design surface that defines a target shape after excavation of the excavation object to an upper surface of the excavation object on which the work machine is placed;
A work machine characterized in that the excavation target surface is set to be higher than the design surface based on the bench height and information related to the site environment acquired in advance. 2. The work machine according to claim 1,
The control device includes:
Calculate the maximum load capacity of the transport vehicle that will be the predetermined soil release position based on the recognition result of the external environment recognition device;
A work machine characterized in that the excavation target surface is set so that the difference in height between the excavation target surface and the design surface becomes greater as the calculated maximum load capacity of the transport vehicle increases. 2. The work machine according to claim 1,
A communication device for acquiring information is further provided.
The control device includes:
Calculating the maximum load capacity of the transport vehicle that will be the predetermined soil release position based on the information acquired via the communication device;
A work machine characterized in that the excavation target surface is set so that the difference in height between the excavation target surface and the design surface becomes greater as the calculated maximum load capacity of the transport vehicle increases. 2. The work machine according to claim 1,
The control device includes:
Measure the height of tracks caused by the travel of a transport vehicle that will be the predetermined soil release position based on the recognition result of the external environment recognition device;
A work machine characterized in that the excavation target surface is set so that the difference in height between the excavation target surface and the design surface increases as the rut height increases. 2. The work machine according to claim 1,
The control device includes:
A work machine characterized in that the excavation target surface is set with a gradient so that the difference in height between the excavation target surface and the design surface becomes greater the closer the excavation target surface is to the work machine. 2. The work machine according to claim 1,
The control device includes:
Recognizing the traveling direction of the transport vehicle that will be the predetermined soil release position based on the recognition result of the external environment recognition device;
A work machine characterized in that the excavation target surface is set with a gradient so that the difference in height between the excavation target surface and the design surface becomes smaller the further the excavation target surface advances in the travel direction of the transport vehicle. 2. The work machine according to claim 1,
A communication device for acquiring information is further provided.
The control device includes:
Recognizing the traveling direction of the transport vehicle that will be the predetermined soil release position based on the information acquired via the communication device;
A work machine characterized in that the excavation target surface is set with a gradient so that the difference in height between the excavation target surface and the design surface becomes smaller the further the excavation target surface advances in the travel direction of the transport vehicle. 2. The work machine according to claim 1,
The control device includes:
A work machine characterized in that the height from a point below a downwardly sloping surface connected to the upper surface of the excavation object where the slope ends to the upper surface of the excavation object is defined as a bench height.

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