JP2020045687A - Work machine - Google Patents

Abstract

To provide a work machine capable of improving calibration accuracy while suppressing increase in labor and time in calibration.SOLUTION: A controller 12 forming on the basis of a synthesis condition and outputting a synthetic image on a display device 17: stores shapes of predetermined calibration markers 20 used for calibration processing; identifies positions of calibration markers 20 in images captured by a plurality of cameras 11a to 11d; calculates distances from the plurality of cameras 11a to 11d to a plurality of characteristic points in the calibration markers 20 based on the images captured by the plurality of cameras 11a to 11d; calculates attachment positions and attachment angles of the plurality of cameras 11a to 11d with respect to the calibration markers 20 based on the calculated distances; and identifies synthesis conditions in forming a synthetic image based on the calculated attachment positions and attachment angles.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a working machine.

  In recent years, computerization and computerization of work machines have progressed, and many electronic devices have been mounted. For example, on a work machine such as a hydraulic excavator, an image of the periphery of a vehicle body is taken by a plurality of cameras, and an image of the image is displayed on a display unit in the cab, so that a worker in the cab can take an image while sitting in a driver's seat. Some of them can be checked and the situation around the vehicle body can be known. In particular, in a working machine such as a hydraulic excavator, the visibility of the worker in the cab around the vehicle body is likely to be limited due to structural reasons. Technology that can accurately grasp is important.

  As a conventional technique for assisting the field of view of a worker in such a cab, for example, Patent Literature 1 discloses a technique in which a plurality of cameras mounted on a vehicle body capture images of the periphery of the vehicle body, and the captured images are synthesized. A technology is disclosed in which a video (hereinafter, referred to as a bird's-eye video for convenience) generated by capturing an overhead view of a vehicle and surroundings from above the vehicle is displayed on a display unit in a cab.

JP 2014-125865 A

  When a bird's-eye view image or the like synthesized from a plurality of images is displayed on the display unit as in the above-described related art, an error from a design value (set value) of a camera mounting position or a mounting angle (hereinafter, mounting position error and (Referred to as “mounting angle error”), a lap or a shift occurs in the synthesized bird's-eye view image. Therefore, it is necessary to correct the mounting position error and the mounting angle error of the camera (that is, perform calibration). As a method for calibrating the mounting position error and the mounting angle error of each camera, for example, a camera (marker) is set in a predetermined range of the shooting range of each camera, and then an image taken by each camera is set. There is a method of calculating a correction value that corrects the lap or shift between each camera (each image) using the marker inside as a reference point, and the lap or shift is suppressed by applying the correction value to the overhead view image generation processing. doing.

  However, when calibrating a plurality of cameras, it is necessary to arrange a plurality of markers around the vehicle, so that the time required for calibration preparation such as marker arrangement and the time required for the calibration itself increase. It is possible to do it. Suppressing the increase in the time required for such calibration is an important issue in actual operation. In particular, when time constraints are severe, such as when assembling machines on a production line such as mass production equipment at a factory or when the camera mounting position of a machine being operated at the operation site has shifted, calibration is It is even more important to suppress an increase in labor and time required for the application.

  The present invention has been made in view of the above, and an object of the present invention is to provide a working machine capable of improving the accuracy of calibration while suppressing an increase in labor and time in calibration.

  The present application includes a plurality of means for solving the above-mentioned problems, but to give an example, a lower traveling body, an upper revolving body provided to be able to pivot with respect to the lower traveling body, and an upper revolving body. A plurality of cameras arranged to photograph the periphery of the vehicle body formed by the lower traveling structure and the upper revolving structure, and a display device that displays a composite image synthesized from images captured by the plurality of cameras, A working machine including a controller that generates the synthesized image based on the synthesizing condition and outputs the synthesized image to the display device, wherein the controller has a predetermined shape to be used for a calibration process in the images captured by the plurality of cameras. Specify the position of the calibration marker, based on the video captured by the plurality of cameras, from the plurality of cameras in the calibration marker Calculating the distances to the number of feature points, calculating the mounting positions and mounting angles of the plurality of cameras with respect to the calibration marker based on the calculated distances, and calculating the combination based on the calculated mounting positions and mounting angles. It is assumed that the synthesis condition when generating the video is specified, the synthesized video is synthesized based on the specified synthesis condition, and the synthesized video is output to the display device.

  According to the present invention, it is possible to improve the accuracy of calibration while suppressing an increase in labor and time in calibration.

FIG. 1 is a side view schematically illustrating a configuration of a hydraulic shovel as an example of a work machine according to an embodiment of the present invention. FIG. 1 is a top view schematically illustrating a configuration of a hydraulic shovel as an example of a work machine according to an embodiment of the present invention. It is a figure which shows the periphery display device of a working machine typically. FIG. 4 is a functional block diagram illustrating processing functions of a video compositing unit of the controller. It is a flowchart which shows a calibration process. It is a figure showing a situation of a calibration marker reflected on a picture. It is a figure showing signs that a calibration marker is located in an overlapped range of a photography range of an adjacent camera. FIG. 9 is a diagram illustrating a state in which a distance from a camera to a calibration marker is calculated. FIG. 3 is a diagram illustrating yaw, roll, and pitch of a camera. FIG. 3 is a diagram illustrating a positional relationship between adjacent cameras. It is a figure showing signs that a calibration marker is arranged at the rear left. FIG. 3 is a diagram illustrating a positional relationship between adjacent cameras. It is a figure showing signs that a calibration marker is arranged at the rear right. FIG. 3 is a diagram illustrating a positional relationship between adjacent cameras. It is a figure showing signs that a calibration marker is arranged at the front left. FIG. 3 is a diagram illustrating a positional relationship between adjacent cameras. It is a figure showing signs that a calibration marker is arranged at the front right. FIG. 3 is a diagram illustrating a positional relationship between adjacent cameras. FIG. 3 is a diagram illustrating a positional relationship between a calibration marker and a camera. FIG. 3 is a diagram illustrating an example of a video synthesis position in a video of a camera. It is a figure which shows typically the mode of the bird's-eye view image synthesized using the image synthesis position.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a hydraulic excavator that forms a vehicle body with a crawler type lower traveling body and an upper revolving superstructure as an example of a work machine will be described. The present invention can be applied to any work machine having an upper swing body that performs a swing operation, regardless of a drive system such as a hydraulic drive type or an electric drive type.

  FIG. 1 is a side view schematically showing a configuration of a hydraulic shovel as an example of a working machine according to the present embodiment, and FIG. 2 is a top view.

  In FIG. 1, a hydraulic excavator 1 supports an upper swing body 3, a multi-joint type front work machine 4 supported on the front side of the upper swing body 3 so as to be able to move up and down, and a swingable upper swing body 3. And a self-propelled crawler-type lower traveling body 2. The upper revolving unit 3 and the lower traveling unit 2 constitute a vehicle body of the excavator 1.

  The upper swing body 3 has a swing frame 5 as a support structure, and a base end of the front work machine 4 is rotatably supported on the front side of the swing frame 5. Further, a counterweight 10 for balancing the weight with the front work machine 4 is attached to the rear side of the turning frame 5. A cab 6 is provided on the left front side of the turning frame 5 so that an operator operating the excavator 1 can get on the cab.

  The cab 6 includes a seat on which an operator sits, and operating devices (not shown) for performing a driving operation of the front work machine 4, a turning operation of the upper revolving unit 3, a traveling operation of the lower traveling unit 2, and the like. The display device 17 is disposed at a position where the operator sitting on the seat is easy to see and does not hinder the external visual field by the operator.

  In addition, a building cover 7 is provided in front of the counterweight 10 to house mounted equipment (both not shown) such as an engine, a hydraulic pump, and a heat exchanger. The building cover 7 is roughly composed of left and right side plates 7A located on the left and right sides of the revolving frame 5 and extending in the front-rear direction, and upper plates 7B extending in the horizontal direction connecting between upper end portions of the respective side plates 7A. The rear side of the building cover 7 is closed by a counterweight 10. An engine cover 8 is provided on the upper surface plate 7B of the building cover 7 to cover the mounted devices housed in the building cover 7 from above.

  A front upper portion of the cab 6 on the front side of the upper revolving unit 3, and upper portions on the left and right of the upper revolving unit 3 (that is, the left and right ends of the upper surface plate 7B of the building cover 7) near the center in the front and rear direction; Cameras 11a to 11d are disposed at the left and right center positions of the camera 10, respectively, such that the periphery of the vehicle body including the vicinity of the vehicle body is a shooting range.

  FIGS. 1 and 2 show an example in which the calibration marker 20 is disposed rearward as viewed from the cab 6. The calibration marker 20 is used for a calibration process of the peripheral display device in the present embodiment, and is, for example, a predetermined shape drawn on a sheet-like member (hereinafter, the shape includes a shape and a size. ). That is, when the calibration marker 20 is photographed by the cameras 11a to 11d of known performance, the calibration marker 20 is determined from the shape of the calibration marker 20 in the video and the shape of the predetermined calibration marker 20. The positional relationship between the camera and the cameras 11a to 11d can be obtained. This will be described later in detail.

  FIG. 3 is a diagram schematically illustrating a peripheral display device of the work machine according to the present embodiment.

  In FIG. 3, the surrounding display device is a display such as a plurality of (for example, four in the present embodiment) cameras 11a to 11d and a monitor (liquid crystal monitor) that displays images captured by the plurality of cameras 11a to 11d. The system includes a device 17, a controller 12 for controlling the overall operation of the surrounding display device, and a personal computer 13 for performing various controls in cooperation with the controller 12.

  The display device 17 displays images taken by the cameras 11a to 11d, images obtained by changing the viewpoints of the images as if they were taken vertically from above (that is, as an upper viewpoint), or each of the cameras 11a to 11d. A screen 15 for displaying an overhead image 18 (composite image obtained by artificially synthesizing an image of the vehicle and its surroundings from the sky above the vehicle in a bird's eye view) generated by synthesizing the images 18a to 18d captured in 11d. Is provided.

  The example illustrated in FIG. 3 illustrates a case where the bird's-eye view video 18 is displayed on the screen 15 of the display device 17. The bird's-eye view image 18 has, for example, a vehicle icon 16 schematically indicating the shape and size of the vehicle in the bird's-eye view image 18 arranged in the center, and cameras 11a, 11c, 11b, and 11d above, below, left, and right of the vehicle icon 16. It is formed by converting the photographed image into images 18a, 18c, 18b, 18d of the upper viewpoint such that the own vehicle is the center, and arranging them. The controller 12 is connected to a video changeover switch 14 for switching the type of video displayed on the screen 15.

  The present invention is applied to the work machine configured as described above, and the controller 12 of the peripheral display device of the work machine according to the present embodiment uses the images displayed on the display device 17 from the images of the cameras 11a to 11d. Is generated.

  FIG. 4 is a functional block diagram showing the processing functions of the video compositing unit of the controller.

  In FIG. 4, a composite image generation unit 120 of the controller 12 includes an image acquisition unit 121 that acquires images captured by the cameras 11a to 11d, a marker shape storage unit 127 that stores a predetermined shape of the calibration marker 20, and A video marker position specifying unit 122 for specifying the position of the calibration marker 20 in the video captured by the plurality of cameras 11a to 11d, and a plurality of cameras 11a to 11d based on the video captured by the plurality of cameras 11a to 11d. A marker distance calculation unit 123 that calculates distances to a plurality of feature points in the calibration marker 20, and mounting positions and mounting of the cameras 11a to 11d with respect to the calibration marker 20 based on the calculation results of the marker distance calculation unit 123. Camera mounting position for calculating the angle The specifying unit 124, a video combining position specifying unit 125 that specifies a combining condition when generating a combined video based on the calculation result of the camera attachment position specifying unit 124, and a combining condition specified by the video combining position specifying unit 125. A video synthesizing unit 126 for synthesizing the synthesized video (overhead video 18) from the cameras 11a to 11d acquired by the video acquiring unit 121 and outputting the synthesized video to the display device 17.

  The marker shape storage unit 127 stores the shape (shape and size) of the calibration marker 20 used for the calibration process. The shape of the calibration marker 20 stored in the marker shape storage unit 127 is set in advance by the marker shape setting unit 130. The marker shape setting unit 130 is, for example, for setting the calibration marker 20 used by the operator for the calibration process from a plurality of calibration marker candidates, and the personal computer 13 may have the function. Alternatively, a setting device (not shown) may be provided in the controller 12.

  FIG. 5 is a flowchart showing the calibration processing.

  In FIG. 5, the image acquisition unit 121 of the composite image generation unit 120 in the controller 12 first acquires images from the cameras 11a to 11d (step S100). Subsequently, when the start of the calibration process is instructed by an input device (not shown) or the like, the video marker position specifying unit 122 determines the shape (shape and size) of the calibration marker 20 stored in the marker shape storage unit 127. Then, the position of the calibration marker 20 in the acquired video is specified (step S110).

  For example, as shown in FIG. 2, when the calibration marker 20 is arranged in the shooting range of the camera 11c behind the upper revolving unit 3, as shown in FIG. The calibration marker 20 appears, and the position of the calibration marker 20 in the video 112c is specified. The method for specifying the position of the calibration marker 20 is not particularly limited, and any method may be used as long as the position of the calibration marker 20 in the video can be specified using a technique such as pattern matching.

  Subsequently, the video marker position specifying unit 122 determines whether the same calibration marker 20 is reflected in the two cameras to be calibrated, that is, the calibration marker 20 is reflected in a position where the photographing ranges of the adjacent cameras overlap. It is determined whether or not there is (Step S120). If the determination result is NO, the processes of Steps S100 and S110 are repeated until the determination result becomes YES.

  In the present embodiment, as shown in FIG. 7, the calibration marker 20 is arranged, for example, so as to be located in the overlapping range of the photographing ranges 111c and 111d of the adjacent cameras 11c and 11d. That is, similarly, calibration is performed on each of the overlapping range of the shooting range of the adjacent cameras 11a and 11b, the overlapping range of the shooting range of the adjacent cameras 11b and 11c, and the overlapping range of the shooting range of the adjacent cameras 11a and 11d. Photographing is performed with the marker 20 positioned so as to be positioned. It is not necessary to photograph the calibration marker 20 simultaneously in a plurality of overlapping ranges, and the calibration marker 20 is photographed at least once in each overlapping range (that is, the position is specified by the video marker position specifying unit 122). I just need.

  Therefore, instead of individually arranging the calibration markers 20 in each overlapping range, for example, one calibration marker 20 is arranged around the vehicle body, and the upper revolving unit 3 is turned with respect to the lower traveling unit 2, The calibration marker 20 may be photographed in each overlapping range of the photographing range. At this time, it is not necessary to photograph the calibration marker 20 in all overlapping ranges in a single swing operation of the upper swing body 3. That is, when there is an overlapping range in which the calibration marker 20 cannot be photographed, it is sufficient that the position of the calibration marker 20 is moved only in the overlapping range so that the calibration marker 20 can be photographed.

  Subsequently, when the determination result in step S120 is YES, that is, when the calibration marker 20 is photographed at least once in all the overlapping ranges and the position in the video is specified, the marker distance calculating unit 123 Then, the distance from each of the plurality of cameras 11a to 11d to the calibration marker 20 is calculated (step S130).

  That is, as shown in FIG. 8, the marker distance calculation unit 123 arranges the calibration markers 21 (here, arranged on the ground 101 in the images 112 a to 112 d (also referred to as camera projection planes) captured by the cameras 11 a to 11 d, respectively. Based on the position and shape (shape and size) of each of the calibration markers 20 shown on the calibration marker 20 from the center (View Point) of each of the cameras 11a to 11d. Calculate the distance to the point. There is no particular limitation on the direction in which the distance is calculated, and for example, a VIO (Visual Inertial Odometry) function or the like can be used. The marker distance calculation unit 123 measures, for example, three or more end points as feature points in order from the camera 11a to 11d on the calibration marker 20.

  Subsequently, the camera attachment position specifying unit 124 attaches the plurality of cameras 11a to 11d to the calibration marker 20 (for example, the x-axis, the y-axis Then, a relative position in the xyz coordinate system defined by the z axis and a mounting angle (yaw, roll, and pitch in the xyz coordinate system as shown in FIG. 9) are calculated (step S140). Since the camera attachment position specifying unit 124 uses the distances to three or more feature points on the calibration marker 20 obtained by the marker distance calculating unit 123, the positional relationship between the plurality of cameras 11a to 11d and the calibration marker 20 is used. (The mounting position and the mounting angle) can be uniquely obtained.

  Further, the camera mounting position specifying unit 124 specifies the positional relationship between the adjacent cameras 11a to 11d based on the positional relationship between the cameras 11a to 11d and the calibration marker 20 based on the calibration markers imaged simultaneously in the same scene. (Step S150). That is, for example, as shown in FIG. 11, the calibration marker 20 is located on the left rear side of the upper revolving unit 3, and an image obtained by photographing the calibration marker 20 in the overlapping photographing range of the adjacent cameras 11 c and 11 d is used. From the obtained positional relationship between the cameras 11c and 11d and the calibration marker 20, the positional relationship between the adjacent cameras 11c and 11d is specified as shown in FIG.

  Similarly, as shown in FIG. 13, the calibration marker 20 is located at the right rear of the upper revolving unit 3, and the calibration marker 20 is obtained by using an image obtained by photographing the calibration marker 20 in the overlapping photographing range of the adjacent cameras 11 b and 11 c. From the positional relationship between each of the cameras 11b and 11c and the calibration marker 20, the positional relationship between the adjacent cameras 11b and 11c is specified as shown in FIG. Similarly, as shown in FIG. 15, the calibration marker 20 is located at the front left of the upper revolving unit 3, and an image obtained by photographing the calibration marker 20 in the overlapping photographing range of the adjacent cameras 11 a and 11 d is used. From the positional relationship between each of the cameras 11a and 11d and the calibration marker 20, the positional relationship between the adjacent cameras 11a and 11d is specified as shown in FIG. Similarly, as shown in FIG. 17, the calibration marker 20 is located at the front right of the upper revolving unit 3, and an image obtained by photographing the calibration marker 20 in the overlapping photographing range of the adjacent cameras 11 a and 11 b is used. From the positional relationship between each of the cameras 11a and 11b and the calibration marker 20, the positional relationship between the adjacent cameras 11a and 11b is specified as shown in FIG.

  In this way, as shown in FIG. 19, the positions of the cameras 11a to 11d and the calibration markers 20 obtained by using the images obtained by photographing the calibration markers 20 in the overlapping shooting ranges of the adjacent cameras 11a to 11d. From the relationship, as shown in FIG. 18, the positional relationship between the adjacent cameras 11a to 11d can be specified.

  Subsequently, the video combining position specifying unit 125 specifies a video combining position as a combining condition when generating a combined video based on the calculation result of the camera attachment position specifying unit 124, and outputs it to the video combining unit 126 ( Step S160), and the process ends.

  FIG. 20 is a diagram illustrating an example of a video synthesis position in a video of a camera. FIG. 21 is a diagram schematically illustrating a state of a bird's-eye view video synthesized using the video synthesis position.

  As shown in FIG. 20, the video synthesis position specifying unit 125 specifies a video synthesis position as a synthesis condition when generating the overhead view video 18 based on the calculation result of the camera attachment position specification unit 124. Here, the image combining position is a point (combining point) at which the positions of images captured by two adjacent cameras are adjusted when the overhead view image 18 is generated. For example, the image combining position of the image 112a of the camera 11a and the image 112b of the camera 11b shown in FIGS. 20 and 21 is the bonding point A, A ′, A ″. Further, the image combining position of the image 112a of the camera 11a with the image 112d of the camera 11d is the bonding point B, B ', B' '. In the present embodiment, the case where the bonding point is obtained from the positional relationship between the adjacent cameras 11a to 11d specified by the camera mounting position specifying unit 124 has been described as an example. For example, three or more characteristic points on the calibration marker 20 used in the above-described method can be used as bonding points.

  The video synthesis position specified as the synthesis condition by the video synthesis position specifying unit 125 is sent to the video synthesis unit 126 and stored. That is, the video synthesizing unit 126 stores and uses the video synthesizing position (bonding point) specified as the synthesizing condition by the video synthesizing position specifying unit 125 in the calibration processing, so that the image around the entire vehicle body can be more accurately viewed. The image 18 can be synthesized. When the calibration process from the video marker position specifying unit 122 to the video combining position specifying unit 125 is not performed, the video combining position specifying unit 125 combines the overhead view video 18 using the stored combining condition.

  Effects of the present embodiment configured as described above will be described.

  When calibrating a plurality of cameras, it is necessary to arrange a plurality of markers around the vehicle, so that the labor involved in preparing for calibration, such as arranging the markers, and the time required for the calibration itself increase. It is possible that Suppressing the increase in the time required for such calibration is an important issue in actual operation. In particular, when time constraints are severe, such as when assembling machines on a production line such as mass production equipment at a factory or when the camera mounting position of a machine being operated at the operation site has shifted, calibration is It is even more important to suppress an increase in labor and time required for the application.

  On the other hand, in the present embodiment, the lower traveling unit 2, the upper revolving unit 3 that is provided to be pivotable with respect to the lower traveling unit 2, and the upper revolving unit 3 are disposed on the lower traveling unit 2 and the upper traveling unit 2. A display for displaying a plurality of cameras 11a to 11d for photographing the periphery of a vehicle body constituted by the revolving superstructure 3 and a combined image (for example, an overhead view image 18) synthesized from images captured by the plurality of cameras 11a to 11d. In a working machine (e.g., the excavator 1) including the device 17 and the controller 12 that generates a synthesized image based on the synthesizing condition and outputs the synthesized image to the display device 17, the controller 12 performs a predetermined calibration used in the calibration process. A marker shape storage unit 127 for storing the shape of the calibration marker 20, and a calibration marker 20 for images captured by the plurality of cameras 11a to 11d. A marker distance for calculating a distance from a plurality of cameras 11a to 11d to a plurality of feature points in a calibration marker 20 based on images captured by a plurality of cameras 11a to 11d and a video marker position specifying unit 122 for specifying a position. A calculating unit 123; a camera mounting position specifying unit 124 that calculates mounting positions and mounting angles of the plurality of cameras 11a to 11d with respect to the calibration marker 20 based on the calculation results of the marker distance calculating unit 123; Based on the calculation result of 124, the image synthesis position specifying unit 125 that specifies the synthesis condition when generating the synthesized image is configured, so that the calibration can be performed while suppressing an increase in labor and time in the calibration. Accuracy can be improved.

  Next, the features of the above embodiments will be described.

  (1) In the above embodiment, the lower traveling unit 2, the upper revolving unit 3 provided to be able to pivot with respect to the lower traveling unit, and the lower traveling unit and the upper A plurality of cameras 11a to 11d for photographing the periphery of the vehicle body constituted by the revolving body, and a display device 17 for displaying a composite image (for example, a bird's-eye image 18) synthesized from images captured by the plurality of cameras. A working machine (e.g., a hydraulic shovel 1) including a controller 12 that generates the synthesized video based on the synthesis condition and outputs the synthesized video to the display device, wherein the controller uses a predetermined calibration marker used in a calibration process. A marker shape storage unit 127 that stores the shape of the calibration marker 20; and a position of the calibration marker in an image captured by the plurality of cameras. An image marker position specifying unit 122; a marker distance calculating unit 123 that calculates distances from the plurality of cameras to a plurality of feature points in the calibration marker based on images captured by the plurality of cameras; A camera mounting position specifying unit that calculates mounting positions and mounting angles of the plurality of cameras with respect to the calibration marker based on a calculation result of the calculating unit; and the combining based on a calculation result of the camera mounting position specifying unit. An image synthesizing position specifying unit 125 for specifying the synthesizing conditions when generating an image is provided.

  Thus, it is possible to improve the accuracy of the calibration while suppressing an increase in labor and time in the calibration.

  (2) In the above-described embodiment, in the work machine according to (1), the composite image includes a view of the vehicle body and surroundings from above the vehicle body including the upper revolving unit 3 and the lower traveling unit 2. The overhead image 18 is a bird's-eye view image 18 obtained by pseudo-synthesizing a video shot in a bird's-eye view. The video synthesis position specifying unit 125 is configured to generate the bird's-eye view video from a plurality of videos captured by the cameras 11a to 11d. Are specified.

  (3) In the above embodiment, in the work machine of (1), the camera attachment position specifying unit 124 determines at least three or more characteristic points in the calibration marker 20 from the plurality of cameras 11a to 11d. The video compositing position specifying unit 125 calculates the mounting positions and the mounting angles of the plurality of cameras based on the distances to the three or more points of the calibration markers in the video captured by the plurality of cameras. The synthesis condition is specified based on the position of the point.

<Appendix>
Note that the present invention is not limited to the above-described embodiment, and includes various modifications and combinations without departing from the gist of the present invention. In addition, the present invention is not limited to the configuration including all the configurations described in the above embodiment, and includes a configuration in which a part of the configuration is deleted. In addition, each of the above-described configurations, functions, and the like may be realized by designing a part or all of them, for example, using an integrated circuit. In addition, the above-described configurations, functions, and the like may be realized by software by a processor interpreting and executing a program that realizes each function.

  DESCRIPTION OF SYMBOLS 1 ... Hydraulic excavator, 2 ... Lower traveling body, 3 ... Upper revolving superstructure, 4 ... Front work machine, 5 ... Revolving frame, 6 ... Cab, 7 ... Building cover, 7A ... Side plate, 7B ... Top plate, 8 ... Engine Cover: 10: counter weight, 11a to 11d: camera, 12: controller, 13: personal computer, 14: video changeover switch, 15: screen, 16: own vehicle icon, 17: display device, 18: overhead view video, 18a to 18d ... Video, 20, 21 Calibration marker, 101 Ground, 111c, 111d Shooting range, 112a to 112d Video, 120 Synthetic video generation unit, 121 Video acquisition unit, 122 Image marker position identification unit, 123 ... Marker distance calculation unit, 124 ... Camera mounting position specification unit, 125 ... Video synthesis position specification unit, 126 ... Video synthesis unit, 127 ... Marker shape storage , 130 ... marker shape setting unit

Claims (3)

An undercarriage,
An upper revolving structure provided so as to be rotatable with respect to the lower traveling structure,
A plurality of cameras arranged on the upper revolving unit and photographing the periphery of a vehicle body formed by the lower traveling unit and the upper revolving unit,
A display device that displays a composite image synthesized from images captured by the plurality of cameras,
A work machine comprising: a controller that generates the synthesized video based on the synthesis condition and outputs the synthesized video to the display device.
The controller specifies the position of a calibration marker having a predetermined shape used in the calibration process in the images captured by the plurality of cameras, and based on the images captured by the plurality of cameras, Calculating distances to a plurality of feature points in the calibration marker, calculating mounting positions and mounting angles of the plurality of cameras with respect to the calibration markers based on the calculated distances, based on the calculated mounting positions and mounting angles. A work machine configured to specify the combination condition when the combined image is generated, to combine the combined image based on the specified combination condition, and to output the combined image to the display device. The work machine according to claim 1,
The synthesized image is a bird's-eye view image obtained by pseudo-synthesizing an image of the vehicle body and surrounding conditions taken from above the vehicle body consisting of the upper revolving structure and the lower traveling structure.
The work machine according to claim 1, wherein the controller specifies a synthesis condition when the overhead view video is generated from a plurality of videos captured by the plurality of cameras. The work machine according to claim 2,
The controller calculates an attachment position and an attachment angle of each of the plurality of cameras based on a distance from the plurality of cameras to at least three or more characteristic points in the calibration marker, and captures images with the plurality of cameras. A work machine characterized in that the combination condition is specified based on positions of three or more feature points of the calibration marker in a video.

Images