JP2017172316A - Shovel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shovel capable of achieving efficient drilling work by measuring sediment pile ranging from inside to outside of a bucket.SOLUTION: A shovel comprises: a lower machinery; an upper machinery that is rotatably mounted on the lower machinery; an attachment, which includes a boom, an arm and a bucket fitted to the upper machinery; a position detection part, which detects a toe position of the bucket; a sediment shape calculation part, which calculates the shape of the sediment drilled by the bucket; and a control part, which calculates a presumed volume based on the toe position of the bucket calculated by the position detection part and the sediment shape calculated by the sediment shape calculation part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an excavator.

  An excavator that detects the amount of earth and sand in a bucket by a rotatable detection plate arranged in the bucket is known (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 3-208920

  When excavating excavation of earth and sand, if the excavator tries to excavate a certain amount or more of earth and sand at a time, the reaction force applied to the bucket may increase, and the excavation work may be stopped. The reaction force applied to the bucket affects not only the earth and sand in the bucket but also the earth and sand pile outside the bucket located in the excavation direction of the bucket.

  However, the excavator according to Patent Document 1 is configured to detect only the amount of sediment in the bucket, and does not consider the sediments outside the bucket that are located in the bucket excavation direction.

  In view of the above problems, it is desirable to provide an excavator capable of measuring an earth and sand pile extending from the inside of the bucket to the outside of the bucket to realize an efficient excavation work.

An excavator according to an embodiment of the present invention is:
A lower traveling body,
An upper swing body mounted so as to be rotatable with respect to the lower traveling body;
An attachment including a boom, an arm, and a bucket attached to the upper swing body;
A position calculating unit for calculating the toe position of the bucket;
An earth and sand shape calculating unit for calculating an earth and sand shape of the ground excavated by the bucket;
A controller that calculates an estimated volume based on the toe position of the bucket calculated by the position calculator and the earth and sand shape calculated by the earth and sand shape calculator.

  By the above-described means, an excavator capable of realizing an efficient excavation work by measuring a sand pile extending from the inside of the bucket to the outside of the bucket can be provided.

It is a side view of the shovel which concerns on the Example of this invention. It is a figure which shows the structural example of a controller. It is a figure explaining an estimated volume. It is a flowchart which shows the excavation control process of the shovel which concerns on the Example of this invention. It is a schematic diagram of an excavator. It is a figure which shows an example of a distance image. It is a figure which shows the relationship between the direction (theta) seen from the stereo camera, and the distance T to the terrestrial feature which exists in the direction (theta). It is a side view of an excavator. It is a side view of an excavator.

  FIG. 1 is a side view showing an excavator according to an embodiment of the present invention.

  The excavator has a crawler-type lower traveling body 1 capable of self-propelling and an upper revolving body 3 mounted on the lower traveling body 1 through a revolving mechanism 2 so as to be capable of revolving.

  A boom 4 is attached to the upper swing body 3. An arm 5 is attached to the tip of the boom 4, and a bucket 6 as an end attachment is attached to the tip of the arm 5.

  The boom 4, the arm 5, and the bucket 6 constitute an attachment, and are hydraulically driven by the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, respectively. A boom angle sensor S1 as a position detector is attached to the boom 4, an arm angle sensor S2 as a position detector is attached to the arm 5, and a bucket angle sensor S3 as a position detector is attached to the bucket 6. .

  The boom angle sensor S1 measures the posture of the boom 4. In the present embodiment, the boom angle sensor S <b> 1 is an acceleration sensor that detects a tilt angle with respect to the horizontal plane and detects a rotation angle of the boom 4 with respect to the upper swing body 3.

  The arm angle sensor S2 measures the posture of the arm 5. In the present embodiment, the arm angle sensor S <b> 2 is an acceleration sensor that detects the rotation angle of the arm 5 relative to the boom 4 by detecting the inclination with respect to the horizontal plane.

  Bucket angle sensor S3 measures the attitude of bucket 6. In the present embodiment, the bucket angle sensor S3 is an acceleration sensor that detects the rotation angle of the bucket 6 with respect to the arm 5 by detecting the inclination with respect to the horizontal plane.

  The boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 are a potentiometer using a variable resistor, a stroke sensor that detects a stroke amount of a corresponding hydraulic cylinder, and a rotary encoder that detects a rotation angle around a connecting pin. Etc.

  The boom 4 is provided with a distance measuring device. The distance measuring device measures the shape of the earth and sand on the ground on which the bucket 6 is excavated by measuring the distance to surrounding features such as the ground. Stereo camera S4 is an example of a distance measuring device. The stereo camera S4 is a camera that can measure the distance to an object by simultaneously photographing the object from a plurality of different directions. In the present embodiment, the stereo camera S4 is attached to the abdominal surface of the boom 4, for example. Then, the earth and sand shape of the earth and sand mountain is measured based on parallax information between two images obtained by simultaneously photographing the earth and sand mountains existing on the surface of the measurement object from two different directions. Specifically, the stereo camera S4 outputs a distance image that represents the difference in distance from the stereo camera S4 by color, brightness, and the like. The distance measuring device may be a range sensor such as a laser range finder, a laser range finder, or a range image sensor. Stereo camera S4 may be provided on arm 5 (typically its abdominal surface). Further, the stereo camera S4 may be provided on both the boom 4 (typically its abdominal surface) and the arm 5 (typically its abdominal surface). In addition to the boom 4, the distance measuring device may be attached to the arm 5 or the bucket 6. The distance measuring device may be attached to the upper part outside the cabin 10 or may be attached to the ceiling inside the cabin 10.

  The upper swing body 3 is provided with a cabin 10 as a cab and is mounted with a power source such as an engine 11. The cabin 10 is provided with a communication device S5.

  In addition to the engine 11, a hydraulic control device such as a hydraulic pump and a control valve, and a pressure sensor 40 as a load detection unit that detects a load applied to the attachment are mounted on the upper swing body 3. The pressure sensor 40 is connected to a hydraulic pump, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, and the like.

  The communication device S5 is a device that controls communication between the shovel and the outside. The communication device S5 controls, for example, wireless communication between a management device at another location and a shovel.

  In the cabin 10, an input device D1, an audio output device D2, a display device D3, and a controller 30 as a control unit are installed.

  The controller 30 functions as a main control unit that performs drive control of the shovel. In this embodiment, the controller 30 is composed of an arithmetic processing unit including a CPU and an internal memory. Various functions of the controller 30 are realized by the CPU executing programs stored in the internal memory.

  The input device D1 is a device for an excavator operator to input various information to the controller 30 and the like. In this embodiment, the input device D1 is a membrane switch attached around the display device D3. A touch panel or the like may be used as the input device D1.

  The audio output device D2 outputs various audio information in response to an audio output command from the controller 30 or the like. In this embodiment, an in-vehicle speaker that is directly connected to the controller 30 is used as the audio output device D2. An alarm device such as a buzzer may be used as the audio output device D2.

  The display device D3 outputs various image information in response to a command from the controller 30. In the present embodiment, an in-vehicle liquid crystal display directly connected to the controller 30 is used as the display device D3 attached to the driver's seat in the cabin 10.

  Next, various functional elements of the controller 30 will be described with reference to FIG. FIG. 2 is a functional block diagram illustrating a configuration example of the controller 30.

  In the present embodiment, the controller 30 estimates the estimated volume of the earth and sand mountain extending from the inside of the bucket 6 to the outside of the bucket 6 in addition to controlling the operation of the entire shovel, comparing the estimated volume with the volume threshold value, and the pressure value. Based on the comparison with the pressure threshold, warning or attachment control is performed.

  The controller 30 includes functional units that perform various functions. In the present embodiment, the controller 30 includes an earth and sand shape calculation unit 31, a toe position calculation unit 32, an estimated volume calculation unit 33, and a determination unit 34.

  The earth and sand shape calculating unit 31 is a functional element that calculates the earth and sand shape of the ground that the bucket 6 is excavating. The earth and sand shape calculating unit 31 calculates the earth and sand shape of the earth and sand mountain extending from the inside of the bucket 6 to the outside of the bucket 6, for example, based on the measurement information from the stereo camera S4. The measurement information of the stereo camera S4 is, for example, luminance data. The luminance data is, for example, luminance data in a distance image, and the larger the value, the closer the distance from the stereo camera S4. The reaction force during excavation is affected not only by the earth and sand in the bucket 6 but also by the earth and sand outside the bucket 6. For example, earth and sand that overflows from the bucket 6 when the excavation operation is completed is also affected. The “sand pile extending from the inside of the bucket 6 to the outside of the bucket 6” of the present embodiment includes the earth and sand that overflows from the bucket 6 when the excavation operation is completed under the running conditions. Therefore, the “sand pile extending from the inside of the bucket 6 to the outside of the bucket 6” in this embodiment is the earth and sand that is estimated to become a digging load in the excavation operation being performed. Hereinafter, the description “sediment mountain extending from the inside of the bucket 6 to the outside of the bucket 6” is also referred to as estimated load earth and sand.

  The toe position calculation unit 32 calculates the toe position of the bucket 6 based on the detection values from the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3. The toe position calculation unit 32 may calculate not only the toe position but also the attitude of the bucket 6.

  The estimated volume calculation unit 33 calculates the estimated volume of the estimated load sediment based on the earth and sand shape information calculated by the earth and sand shape calculation unit 31 and the toe position information of the bucket 6 calculated by the toe position calculation unit 32.

  The determination unit 34 monitors the estimated volume calculated by the estimated volume calculation unit 33 and the pressure value output from the pressure sensor 40 to determine whether or not to perform warning or attachment control. In this embodiment, a cylinder pressure from a pressure sensor connected to the bucket cylinder 9 may be used as the pressure value. The determination unit 34 determines whether or not to perform warning or attachment control based on the comparison between the estimated volume and the volume threshold value and the comparison between the pressure value and the pressure threshold value.

Next, the estimated volume will be described with reference to FIG. FIG. 3 is a diagram illustrating the estimated volume. The estimated load earth and sand K includes earth and sand K1 in the bucket 6 and earth and sand K2 located near the outside of the bucket 6 located in the excavation direction of the bucket 6. Estimated volume V includes a sediment volume _{V 1} of the sediment K1, and a sediment volume _{V 2} of the sediment K2. X is the toe position of the bucket 6. The earth and sand K2 located in the vicinity outside the bucket 6 of the present embodiment is raised from the ground surface G by excavation operation. The earth and sand K2 is earth and sand estimated to be scooped up by the bucket 6 when the excavation operation is continued as it is. The ground surface G refers to the ground surface at the excavation position before excavation.

  The estimated volume calculator 33 can calculate the estimated volume V based on the earth and sand shape of the estimated load earth and sand K calculated by the earth and sand shape calculator 31 and the toe position of the bucket 6 calculated by the toe position calculator 32.

  The estimated volume V calculated by the estimated volume calculation unit 33 is volume information and does not include information on weight. The excavation reaction force greatly depends on the volume and weight of the earth and sand to be excavated. Therefore, the controller 30 of the present embodiment performs control based on the estimated volume V and the pressure value (cylinder pressure) of the pressure sensor 40 at that time. This point will be described later.

  In the present embodiment, the following method may be used as a method for calculating the volume of excavated earth and sand.

  In the first method, the controller 30 first determines the excavation start determination based on the load applied to the bucket 6. In this case, bucket cylinder pressure or the like is used. Thereafter, it is determined that excavation is continued while a load is applied to the bucket 6. Then, the volume of earth and sand to be excavated is calculated based on the shape of the ground surface G and the trajectory information of the tip of the bucket 6. The shape of the ground surface G may be obtained by the stereo camera S4, or may be calculated from a toe trajectory at the previous excavation.

  In the second method, as shown in FIG. 3, the controller 30 calculates a change in the shape of the excavation target ground using the stereo camera S4. After that, the volume of excavated earth and sand is calculated from the toe position of the bucket 6, the angle (posture) of the bucket 6, and the change in the shape of the excavation target ground calculated by the stereo camera S4.

  In the present embodiment, the shape of the earth and sand K2 is estimated by the stereo camera S4 based on the measured value and the position of the tip of the bucket.

  Next, the excavation control process of the present embodiment executed by the controller 30 will be described with reference to FIG. FIG. 4 is a flowchart of the excavation control process. This process may be executed once in a predetermined bucket posture, or may be repeatedly executed in a plurality of bucket postures.

  When the excavation work is started and the predetermined bucket posture is reached, the estimated volume calculation unit 33 of the controller 30 is a step (hereinafter abbreviated as ST) 1 and a sand pile extending from the bucket 6 to the outside of the bucket 6 (estimated load sediment K). The estimated volume V is calculated. Specifically, the estimated volume calculation unit 33 calculates the estimated load earth and sand K based on the earth and sand shape of the estimated load earth and sand K calculated by the earth and sand shape calculation part 31 and the toe position of the bucket 6 calculated by the toe position calculation part 32. The estimated volume V is calculated.

  The controller 30 acquires the cylinder pressure P from the pressure sensor 40 connected to the bucket cylinder 9 in ST2.

Thereafter, the determination unit 34 of the controller 30 determines whether the estimated volume V calculated by the estimated volume calculation unit 33 is greater than or equal to a predetermined value V _TH1 as the first volume threshold (ST3). The predetermined value V _TH1 of this embodiment is set to a volume that is two to three times the bucket volume.

When the estimated volume V is equal to or greater than the predetermined value V _TH1 (Y in step ST3), the determination unit 34 determines whether the cylinder pressure P acquired from the pressure sensor 40 is equal to or greater than the predetermined value P _TH1 as the pressure threshold ( ST4).

When the cylinder pressure P is greater than or equal to the predetermined value _PTH1 (Y in step ST4), the determination unit 34 outputs a warning signal to the sound output device D2 (ST5). The determination unit 34 may output a warning signal to the display device D3 and display it on the screen. In addition, the determination unit 34 controls the attachment and outputs a signal for performing a reduction operation control for reducing a load applied to the attachment. In the present embodiment, the controller 30 performs operation control for raising the boom 4. At this time, the controller 30 preferably performs control to raise the boom 4 by flowing hydraulic oil into the boom cylinder 7.

On the other hand, when it is determined in ST3 that the estimated volume V is less than the predetermined value V _TH1 (N in step ST3), the determination unit 34 determines whether the cylinder pressure P is greater than or equal to the predetermined value P _{TH2 in} ST6. The relationship between the predetermined value P _TH2 and the predetermined value P _TH1 is “P _TH2 > P _TH1 ”.

When the cylinder pressure P is less than the predetermined value _PTH2 (N in step ST6), the controller 30 ends the process without executing ST5.

If the cylinder pressure P is greater than or equal to the predetermined value _PTH2 (Y in step ST6), the determination unit 34 outputs a warning signal to the sound output device D2 (ST5). In addition, the determination unit 34 performs a reduction operation control that controls the attachment and reduces the load applied to the attachment. In the present embodiment, the controller 30 performs operation control for raising the boom 4.

When the cylinder pressure P is less than the predetermined value _{PTH1 in} ST4 (N in step ST4), the determination unit 34 uses the estimated volume V calculated by the estimated volume calculation unit 33 in ST1 as a second volume threshold. It is determined whether or not the value is V _TH2 or more (ST7). The relationship between the predetermined value V _TH2 and the predetermined value V _TH1 is “V _TH2 > V _TH1 ”.

When the estimated volume V is less than the predetermined value V _TH2 (N in step ST7), the controller 30 ends the process without executing ST5.

On the other hand, when the estimated volume V is greater than or equal to the predetermined value V _TH2 (Y in step ST7), the determination unit 34 outputs a warning signal to the audio output device D2 (ST5). In addition, the determination unit 34 performs a reduction operation control that controls the attachment and reduces the load applied to the attachment. In the present embodiment, the controller 30 performs operation control for raising the boom 4.

  As described above, since the excavator of the present embodiment has the stereo camera S4 attached to the boom 4 as an attachment, the earth and sand shape of the earth and sand mountain extending from the inside of the bucket 6 to the outside of the bucket 6 can be detected. In addition, the controller 30 of this embodiment is configured to perform a reduction operation control that reduces the warning or attachment load based on the comparison between the estimated volume and the volume threshold and the comparison between the pressure value and the pressure threshold. Therefore, the excavator of the present invention can always excavate an appropriate amount of soil and improve the efficiency of excavation work.

  In the above-described embodiment, the earth and sand shape calculating unit 31 calculates the earth and sand shape of the ground excavated by the bucket 6 based on the output of the stereo camera S4. The earth and sand shape calculating unit 31 recognizes the shape of the excavation target ground based on the distance image output from the stereo camera S4, for example.

  However, the earth and sand shape calculation unit 31 may not be able to distinguish between the shape of the attachment and the shape of the excavation target ground. This is because when the tip of the attachment is buried in the excavation target ground, both are integrated. Specifically, this is because the distance from the stereo camera S4 to the tip of the attachment is substantially equal to the distance from the stereo camera S4 to the excavation target ground. When the shape of the attachment and the shape of the ground to be excavated cannot be distinguished, the earth and sand shape calculating unit 31 recognizes a part of the shape of the attachment as the shape of the earth and sand, for example, and the earth and sand of the ground on which the bucket 6 is excavating. There is a possibility that the shape of this cannot be calculated accurately.

  Therefore, the earth and sand shape calculation unit 31 distinguishes between the shape of the attachment and the shape of the excavation target ground based on the output of the stereo camera S4 as the distance measuring device.

  Here, with reference to FIGS. 5-7, the process which distinguishes the shape of an attachment and the shape of the excavation target ground is demonstrated. 5A and 5B are schematic diagrams of the shovel, in which FIG. 5A shows a side view and FIG. 5B shows a top view. FIG. 6 shows a distance image GD output from the stereo camera S4. FIG. 7 is a diagram illustrating a relationship between the direction θ viewed from the stereo camera S4 and the distance T to the feature existing in the direction θ.

  The stereo camera S4 is attached to the abdominal surface of the boom 4 as shown in FIG. A region R represented by dot hatching in FIGS. 5A and 5B indicates a photographing range of the stereo camera S4.

  The distance image GD output from the stereo camera S4 is, for example, an image of 320 horizontal pixels × 240 vertical pixels. Based on the value of each pixel of the distance image GD, the controller 30 can calculate the distance between the stereo camera S4 and the subject (feature) reflected in each pixel. In this embodiment, the subject (feature) includes the abdominal surface of the attachment and the excavation target ground.

  Stereo camera S4 acquires the distance to each point on intersection line IL between virtual vertical plane VP (see FIG. 5B) that cuts through the attachment and the abdominal surface of the attachment and each of the ground to be excavated. A dashed line in FIG. 5A indicates a part of the intersection line IL, and each point on the intersection line IL includes a point P0 to a point P3.

  The point P0 is a point on the abdominal surface of the arm 5 and corresponds to the pixel G0 located at the top of the vertical pixel row GL including the center pixel GC of the distance image GD as shown in FIG. The controller 30 can calculate the distance T0 between the stereo camera S4 and the point P0 based on the pixel value of the pixel G0.

  The point P1 is a point on the boundary between the attachment and the excavation target ground (hereinafter referred to as “boundary point”), and corresponds to the pixel G1 above the central pixel GC as shown in FIG. Yes. The controller 30 can calculate the distance T1 between the stereo camera S4 and the point P1 based on the pixel value of the pixel G1. The angle θ1 is an angle formed between the line segment S4-P0 and the line segment S4-P1, and is associated with the pixel G1 in advance.

  The point P2 is a point on the excavation target ground, and corresponds to a pixel G2 below the center pixel GC as shown in FIG. The controller 30 can calculate the distance T2 between the stereo camera S4 and the point P2 based on the pixel value of the pixel G2. The angle θ2 is an angle formed between the line segment S4-P0 and the line segment S4-P2, and is associated with the pixel G2 in advance.

  The point P3 is a point on the excavation target ground, and corresponds to the pixel G3 positioned at the bottom of the vertical pixel row GL including the center pixel GC of the distance image GD as shown in FIG. The controller 30 can calculate the distance T3 between the stereo camera S4 and the point P3 based on the pixel value of the pixel G3.

FIG. 7A is a graph showing the relationship between the angle θ and the distance T. The angle θ is an angle formed between the line segment S4-P0 and the line segment S4-Pn (a line segment connecting the stereo camera S4 and an arbitrary point Pn on the intersection line IL). FIG. 7B is a graph showing the relationship between the angle θ and the value (dT / dθ) obtained by differentiating the distance T once with the angle θ. FIG. 7C is a graph showing the relationship between the angle θ and the absolute value (| d ² T / dθ ² |) of the value obtained by differentiating the distance T twice by the angle θ.

  As shown in FIG. 7A, the earth and sand shape calculating unit 31 obtains the distance T to each point on the intersection line IL at a predetermined angular interval Δθ. Specifically, the pixel value of each pixel in the pixel row GL in FIG. 6 is acquired. By arranging the pixel values of each pixel in the pixel row GL in order from the top, the earth and sand shape calculating unit 31 can acquire the transition of the distance T corresponding to each pixel as shown in FIG.

  Thereafter, the earth and sand shape calculation unit 31 calculates a value (dT / dθ) obtained by differentiating the distance T once by the angle θ. Specifically, the difference between adjacent pixel values (distance T) in the pixel row GL is calculated as a once differentiated value (dT / dθ). Thereby, the earth and sand shape calculation part 31 can acquire transition of 1 time differential value (dT / d (theta)) as shown in FIG.7 (B).

Then, the earth and sand shape calculation part 31 calculates the absolute value (| d ² T / dθ ² |) of the value obtained by differentiating the distance T twice by the angle θ. Specifically, the absolute value of the difference between adjacent one-time differential values (dT / dθ) is calculated as a second-time differential absolute value (| d ² T / dθ ² |). Thus, earth and sand shape calculating unit 31, FIG. 7 second derivative absolute value as shown in (C) can be obtained a transition of ^{(| | d 2 T / dθ} 2).

Thereafter, the earth and sand shape calculating unit 31 compares the second-order differential absolute value (| d ² T / dθ ² |) with a predetermined threshold TH1, and the second-order differential absolute value (| d ² T / dθ ² |) is A point corresponding to the angle θ when the threshold value TH1 is exceeded is derived as a boundary point. In the present embodiment, the earth and sand shape calculation unit 31 derives a point P1 corresponding to the angle θ1 as a boundary point.

In this way, the earth and sand shape calculating unit 31 acquires the distance T to each point on the intersection line IL between the virtual vertical plane VP that cuts through the attachment and the abdomen and the ground of the attachment. And an attachment and the ground which the bucket 6 is excavating are distinguished based on the change of the distance T of each point arranged in order along the intersection line IL. For example, a point where the rate of change of the distance T with respect to the angle θ changes suddenly is derived as a boundary point between the attachment and the ground. In the present embodiment, the rate of change of the distance T with respect to the angle θ changes abruptly at a point on the intersection line IL corresponding to the angle when the double differential absolute value (| d ² T / dθ ² |) exceeds the threshold value TH1. Derived as a place to do. However, the earth and sand shape calculation unit 31 may derive the place where the change rate of the distance T with respect to the angle θ changes suddenly by another method.

  Then, the earth and sand shape calculation part 31 calculates the shape of the earth and sand of the ground which the bucket 6 is excavating by deriving each point corresponding to an angle of the angle θ1 or more as a point representing the ground. In the present embodiment, the points corresponding to the angle θ1 or more are derived as points representing the ground, and then the shape of the earth and sand on which the bucket 6 is excavated is calculated.

  Thereafter, the earth and sand shape calculating unit 31 may display the calculated earth and sand shape on the display device D3. The earth and sand shape calculation unit 31 displays the shape of the excavation target ground on the display device D3 based on the excavator center point based on, for example, the posture of the attachment, the attachment position of the stereo camera S4 on the attachment, the direction θ, and the distance T. The excavator center point is, for example, the intersection of the excavator's pivot axis and the excavator's virtual ground plane. The earth and sand shape calculation unit 31 may display the shape of the excavation target ground three-dimensionally and may display a cross section of the virtual vertical plane VP two-dimensionally. FIG. 7D shows a display example of a cross section in the virtual vertical plane VP. The origin O corresponds to the excavator center point, the Z axis corresponds to the vertical axis, and the X axis corresponds to the horizontal axis extending in the extension direction of the attachment. The alternate long and short dash line represents the shape of the ground, and the broken line represents the shape of the attachment.

Also, sediment shape calculating unit 31, the second derivative absolute value is compared to a threshold TH1 may limit the number of ^{(| | d 2 T / dθ} 2). This is because the boundary point is considered to exist near the tip of the attachment. Moreover, it is for avoiding useless calculation processing. For example, the earth and sand shape calculating unit 31 compares the second-order differential absolute value (| d ² T / dθ ² |) corresponding to each of the angles θ in the angle range W with the threshold value TH1, and the angle outside the angle range W The comparison between the absolute value of the second derivative (| d ² T / dθ ² |) corresponding to each θ and the threshold value TH1 is omitted. The earth and sand shape calculation unit 31 may change the angle range W according to the posture of the attachment derived based on the outputs of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3. Moreover, the earth-and-sand shape calculation part 31 may derive | lead-out the boundary point of the boom 4 and the arm 5, and the boundary point of the arm 5 and the bucket 6 by the same method.

  Next, another process for distinguishing between the shape of the attachment and the shape of the excavation target ground will be described with reference to FIG. FIG. 8 is a side view of the shovel and corresponds to FIG. The configuration of FIG. 8 is different from the configuration of FIG. 5A in which the laser range finder S4A is adopted as the distance measuring device and the stereo camera S4 is adopted as the distance measuring device, but is common in other points. To do. Therefore, the description of the common part is omitted, and the different part is described in detail.

  The laser range finder S4A is attached to the abdominal surface of the boom 4 as shown in FIG. The laser range finder S4A emits a laser while changing the emission direction θ at a predetermined angular interval Δθ, and measures the distance T to the feature that reflects the laser light.

  The earth and sand shape calculation unit 31 acquires the distance T to each point on the intersection line IL at a predetermined angular interval Δθ based on the output of the laser range finder S4A. By arranging the acquired distances T in time series, the earth and sand shape calculation unit 31 can acquire the transition of the distances T as shown in FIG. 7A, similarly to the case where the stereo camera S4 is employed.

  With this configuration, the earth and sand shape calculating unit 31 can derive the boundary points in the same manner as when the stereo camera S4 is employed. And earth and sand shape calculation part 31 derives each point corresponding to an angle more than an angle corresponding to a boundary point as a point showing the ground. Thereby, distinguishing from the shape of an attachment, the shape of the earth and sand of the ground which the bucket 6 is excavating can be derived.

  Next, still another process for distinguishing the shape of the attachment from the shape of the excavation target ground will be described with reference to FIG. FIG. 9 is a side view of the shovel and corresponds to FIG. The configuration of FIG. 9 differs from the configuration of FIG. 5A in terms of the shooting range of the stereo camera S4, but is common in other respects. Therefore, the description of the common part is omitted, and the different part is described in detail.

  In FIG. 9, the stereo camera S4 is attached to the abdominal surface of the boom 4 so that a part of the abdominal surface on the tip side of the boom 4, the abdominal surface of the arm 5, the abdominal surface (inner surface) of the bucket 6, and the ground can be photographed. A region R represented by dot hatching in FIG. 9 indicates a shooting range of the stereo camera S4.

  With this configuration, the earth and sand shape calculating unit 31 can derive not only the boundary point between the bucket 6 and the excavation target ground but also the boundary point between the boom 4 and the arm 5 and the boundary point between the arm 5 and the bucket 6. The same applies to the case where a laser range finder S4A is employed instead of the stereo camera S4.

  As described above, the earth and sand shape calculation unit 31 distinguishes between the attachment and the ground on which the bucket 6 is excavated, and derives the shape of the earth and sand on the ground on which the bucket 6 is excavated. Therefore, it can prevent that the shape of an attachment is recognized as the shape of earth and sand. Or it can prevent that the shape of earth and sand is recognized as the shape of an attachment. As a result, the earth and sand shape calculation unit 31 can accurately derive the earth and sand shape.

  Moreover, in the above-mentioned Example, the controller 30 estimated volume of estimated load earth and sand based on the earth and sand shape information which the earth and sand shape calculation part 31 calculated, and the toe position information of the bucket 6 which the toe position calculation part 32 calculated. Is calculated. Then, the controller 30 monitors the estimated volume calculated by the estimated volume calculation unit 33 and the pressure value output from the pressure sensor 40, and determines whether to perform warning or attachment control. However, the controller 30 may use the earth and sand shape information calculated by the earth and sand shape calculating unit 31 for other uses such as calculation of excavation load.

  Moreover, the earth-and-sand shape calculation part 31 can distinguish the attachment and the ground which the bucket 6 is excavating based on the output of distance measuring devices, such as stereo camera S4 and laser range finder S4A. Therefore, the distance measuring device does not need to avoid the attachment entering the measurement range. Therefore, the mounting position of the distance measuring device is not excessively limited. Therefore, the distance measuring device may be attached to the upper swing body 3 so that, for example, the abdominal surface of the attachment and the excavation target ground can be photographed.

  Moreover, the earth and sand shape calculation part 31 may recognize the attitude | position of an attachment by the method similar to when distinguishing an attachment and the ground. For example, the boundary point between the upper swing body 3 and the boom 4, the boundary point between the boom 4 and the arm 5, the boundary point between the arm 5 and the bucket 6 and the like may be derived based on the output of the distance measuring device. Moreover, the earth and sand shape calculation part 31 may derive | lead-out the angle of the boom 4 with respect to the upper turning body 3, the angle of the arm 5 with respect to the boom 4, the angle of the bucket 6 with respect to the arm 5, etc.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  DESCRIPTION OF SYMBOLS 1 ... Lower traveling body 2 ... Turning mechanism 3 ... Upper turning body 4 ... Boom 5 ... Arm 7 ... Boom cylinder 8 ... Arm cylinder 9 ... Bucket cylinder 10. ..Cabin 11 ... Engine 30 ... Controller 31 ... Sediment shape calculation unit 32 ... Toe position calculation unit 33 ... Estimated volume calculation unit 34 ... Determination unit S1 ... Boom angle sensor S2 ... Arm angle sensor S3 ... Bucket angle sensor S4 ... Stereo camera S4A ... Laser range finder S5 ... Communication device D1 ... Input device D2 ... Audio output device D3 ... Display device GD ... Distance image

Claims (8)

A lower traveling body,
An upper swing body mounted so as to be rotatable with respect to the lower traveling body;
An attachment including a boom, an arm, and a bucket attached to the upper swing body;
A position calculating unit for calculating the toe position of the bucket;
An earth and sand shape calculating unit for calculating an earth and sand shape of the ground excavated by the bucket based on an output of a distance measuring device;
An excavator comprising: a control unit that calculates an estimated volume based on the toe position of the bucket calculated by the position calculation unit and the shape of the earth and sand calculated by the earth and sand shape calculation unit. A load detection unit for detecting a load applied to the attachment;
The control unit performs warning or load reduction operation control when the calculated estimated volume is equal to or greater than a first volume threshold and the load detected by the load detection unit is equal to or greater than a predetermined pressure threshold. The excavator according to claim 1.   The excavator according to claim 2, wherein the control unit performs warning or load reduction operation control when the calculated estimated volume is equal to or greater than a second volume threshold. The earth and sand shape calculating unit calculates the earth and sand shape of the ground that the bucket is excavating by distinguishing the attachment and the ground that the bucket is excavating.
The excavator according to any one of claims 1 to 3. A lower traveling body,
An upper swing body mounted so as to be rotatable with respect to the lower traveling body;
An attachment including a boom, an arm, and a bucket attached to the upper swing body;
A sand and sand shape calculating unit that calculates the shape of the earth and sand on which the bucket is excavating based on the output of the distance measuring device,
The earth and sand shape calculating unit calculates the earth and sand shape of the ground that the bucket is excavating by distinguishing the attachment and the ground that the bucket is excavating.
Excavator. The earth and sand shape calculation unit displays the calculated earth and sand shape on a display device.
The excavator according to any one of claims 1 to 5. The earth and sand shape calculation unit is based on the output of the distance measuring device attached to the abdominal surface of the attachment, up to each point on the intersection line between the virtual vertical surface that cuts through the attachment, the abdominal surface of the attachment, and each of the ground. Obtaining a distance, and distinguishing the attachment and the ground on which the bucket is excavated based on a change in the distance of each point arranged in order along the intersecting line;
The excavator according to any one of claims 4 to 6. The distance measuring device is at least one of a stereo camera, a laser range finder, and a distance image sensor.
The excavator according to any one of claims 1 to 6.

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