JP2017053627A - Angle detecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction machinery angle detecting apparatus that can be easily fitted after other items, is free from worry about trouble, and can detect the angles of a revolving body relative to a running body accurately and in a timely way.SOLUTION: An detecting apparatus 1 is equipped with a camera 4 installed on a revolving body 3 that can revolve relative to a running body 2 and photograph a working apparatus W, which is another link than the revolving body 3; an angle detector 5 that detects a relative angle between each pair of adjoining links on the basis of images photographed by the camera 4; and an attitude identifier 6 that identifies the attitude of the working apparatus W relative to the revolving body 3 on the basis of the angles detected by the angle detector 5. The apparatus extracts edges of a boom 7, an arm 8 and an attachment 9, which are links of the working apparatus W, and figures out the relative angle of each.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an angle detection device.

  A construction machine used for civil engineering construction work includes a traveling body that can travel with a crawler, a revolving body that is turnably attached to the traveling body, and a boom that is swingably connected to the revolving body in a vertical direction. An arm that is connected to a boom so as to be swingable in the vertical direction and an attachment that is connected to the tip of the arm so as to be swingable in the vertical direction are known.

  In such a construction machine, since the civil engineering construction work is performed while changing the posture of the swinging body, boom, arm and attachment attached on the traveling body, the center of gravity of the traveling vehicle is reduced when an unreasonable operation is performed. There is a risk of falling out of balance and falling.

  In recent years, safety devices that utilize zero moment points (hereinafter simply referred to as “ZMP”) have been developed to prevent falling. ZMP is a point on the ground where the moment due to inertial force, gravity and external force acting on the object becomes zero, and when the ZMP is located near the center of the traveling body in plan view, the traveling vehicle is overturned. Such a moment does not occur. Therefore, when the ZMP is located in the vicinity of the center of the traveling body viewed in plan, the traveling vehicle is less likely to fall, and the closer the ZMP is to the end of the traveling body viewed in plan, the easier the traveling vehicle falls. . Therefore, if it is determined where the ZMP is located, it is possible to evaluate the ease with which the traveling vehicle falls.

  To obtain the ZMP, the world coordinates of the swivel body, boom, arm, and attachment are required. In order to obtain this, the posture of the swinging body relative to the traveling body, the posture of the boom relative to the swinging body, the posture of the arm relative to the boom, and the posture of the attachment relative to the arm must be specified.

  Conventionally, as an apparatus for specifying the posture of a swinging body, a boom, an arm and an attachment, an angle sensor is used to determine the angle of the swinging body with respect to the traveling body, the angle of the boom with respect to the swinging body, the angle of the arm with respect to the boom, and the attachment angle with respect to the arm. (For example, refer to Patent Document 1).

  Further, as another device for specifying the posture of the swinging body, boom, arm, and attachment, a marker provided on the boom and arm is photographed with a camera to obtain the coordinates of the marker, and the coordinates of the obtained marker and the marker held in advance An apparatus for identifying these postures by collating with position data has also been developed (see, for example, Patent Document 2).

JP 2014-001596 A JP 2008-063774 A

  However, in the apparatus disclosed in Patent Document 1, an angle sensor is used to detect the angle of a swiveling body or the like, and it is necessary to consider the protection of the angle sensor and the handling of wiring so that it can withstand harsh usage environments. It becomes.

  In addition, the apparatus disclosed in Patent Document 2 does not require an angle sensor and can solve the above problem by installing the camera in a safe place (cab). It is necessary to collate the coordinates. For this reason, the apparatus of Patent Document 2 needs to have a large amount of marker position data, which requires a large-capacity memory and increases the cost.

  Accordingly, the present invention has been devised to solve the above-mentioned problems, and its object is to provide an angle detection device that does not require a sensor, has no problem of sensor protection, and can reduce the cost. .

  In order to achieve the above object, an angle detection device for a construction machine according to the present invention photographs other links with a camera attached to the end link of the movable member, and determines the relative angles of the other links from the captured images. Ask. In this way, the angle detection device does not use sensors, so there is no worry about sensor failure, and the camera can be installed in a safe place with a high degree of freedom, so it can withstand harsh usage environments, It is not necessary to store a huge amount of map position data, and a large capacity memory is not required, so the cost can be reduced.

  In addition, since the angle detection device according to the second aspect includes a posture specifying unit that specifies the posture of another link from the obtained relative angle, it is necessary for ZMP calculation of a construction machine or the like to which the angle detection device is applied. Angle information is obtained.

  Furthermore, in the angle detection device according to claim 3, the movable member has three or more links, and the angle detection unit obtains the relative angle of the link closest to the end link, and the second and subsequent close from the end link. For the link, the relative angle is obtained based on the posture of the immediately preceding link specified by the posture specifying unit. Therefore, in this angle detection device, even when the movable member has a large number of links, the relative angles of all the links can be easily detected.

  In the angle detection device according to the fourth aspect, the angle detection unit processes the image captured by the camera, detects an edge of another link, and obtains a relative angle. Furthermore, in the angle detection device according to claim 5, the angle detection unit processes the image captured by the camera, extracts a predetermined portion of another link from the image captured by the camera, and A straight line connecting the rotation center in another link is obtained, and a relative angle is obtained based on this straight line. Therefore, the angle detection device configured in this way can detect the relative angle from one image, not from the continuous images taken by the camera, and can detect the angle in a timely manner without taking time.

  Further, in the angle detection device according to claim 6, the link at the end of the movable member is used as a revolving body of the construction machine, and the other link is a working device rotatably connected to the revolving body of the construction machine, It is designed to be installed in the revolving body cabin. As described above, since the camera that captures an image necessary for detecting the relative angle is accommodated in the cabin, the camera is protected from the external environment of the construction machine. Therefore, in the angle detection device according to the sixth aspect, the camera is not exposed to wind and rain, and is protected from the flying of stones and earth and sand during civil engineering work, so that stable relative angle detection is possible.

  The angle detection device of the present invention does not require a sensor, and there is no problem of sensor protection, and the cost can be reduced.

It is the figure which showed an example of the system configuration | structure of the angle detection apparatus in 1st embodiment. It is the figure which applied the angle detection apparatus in 1st embodiment to the construction machine. It is a figure which shows the image which the camera of the angle detection apparatus in 1st embodiment image | photographed. It is a figure which shows the image after the edge image process of the image image | photographed with the camera. It is a figure which shows the image which carried out the projective transformation process of the image of FIG. It is a figure which shows the relationship between the connection axis | shaft of a link, and an edge. It is a figure explaining the process which extracts an edge. It is a figure explaining the process which extracts an edge. It is a figure explaining the process which calculates | requires an angle from the edge of the image image | photographed with the camera. It is a figure explaining the process which calculates | requires an angle from the edge of the image image | photographed with the camera. It is the figure which showed the structural example of the hardware resource of the angle detection apparatus in 1st embodiment. It is the flowchart which showed the process sequence of the angle detection in the angle detection apparatus in 1st embodiment. It is the figure which showed an example of the system configuration | structure of the angle detection apparatus in 2nd embodiment. It is a figure which shows the image which carried out the projective transformation process of the image image | photographed with the camera. It is the flowchart which showed the process sequence of the angle detection in the angle detection apparatus in 2nd embodiment.

<First embodiment>
The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, the angle detection device 1 according to the present embodiment is applied to the construction machine C so as to detect the angle of each part of the work device W in the construction machine C. The angle detection device 1 can be used to detect the relative angle of a link in a device or machine other than the construction machine C.

  Specifically, the angle detection device 1 is attached to the swivel body 3 that is the link at the end of the movable member M, and can capture the work device W that is a link other than the swivel body 3. An angle detection unit 5 that detects a relative angle between adjacent links based on an image taken by the camera, and an attitude that specifies the posture of the working device W with respect to the revolving structure 3 based on the angle detected by the angle detection unit 5 The specific part 6 is provided.

  The construction machine C includes a traveling body 2 including a crawler 2a and capable of traveling, and a movable member M connected to the traveling body 2 so as to be able to turn. The movable member M includes a revolving body 3 that is pivotably coupled to the traveling body 2 and a work device W that is coupled to the revolving body 3 so as to be swingable in the vertical direction. In this example, the work device W includes a boom 7 connected to the swing body 3 so as to be swingable in the vertical direction, an arm 8 connected to the boom 7 so as to be swingable in the vertical direction, and a swinging motion to the arm 8 in the vertical direction. And an attachment 9 which is movably connected.

  In the illustrated construction machine C, the attachment 9 is a bucket. However, in addition to the bucket, the construction machine C can be changed to a breaker, a cutter, a grapple or the like according to the use of work. The movable member M is configured as an articulated link mechanism in which each of the revolving body 3, the boom 7, the arm 8, and the attachment 9 is used as a link, and these are connected in series so as to be relatively rotatable. And the movable member M uses the revolving body 3 as a terminal link, and uses the boom 7, the arm 8, and the attachment 9 which are the other working devices W as other links.

  The number of links constituting the movable member M may be two or more. The movable member M is a swivel body, the working device W is a crane, and the construction machine C is composed of two links. It may be a crane truck. Further, in this example, the angle detection device 1 is used for detecting the relative angle of the movable member M in the construction machine C. However, the movable member M is not limited to the upper structure of the construction machine C, and is connected so as to be relatively rotatable in series. What is necessary is just to be comprised by the some link made.

  The camera 4 is configured as a CCD camera including a CCD (charge coupled device, not shown), a lens (not shown), and a focus adjustment unit (not shown). In this example, the camera 4 is located in the cabin 3a of the swivel body 3. It is installed so that the whole working device W can be photographed. Specifically, the camera 4 is attached to the revolving unit 3 so that the side of the working device W can be photographed as shown in FIG. In addition, the camera 4 may be installed so that the revolving body 3 that is a link at the end of the movable member M can also be photographed partially or entirely, or may be attached outside the cabin 3a of the revolving body 3.

  In addition, the camera 4 continuously captures a preset capturing range at a predetermined frame rate, converts the captured image into an electrical signal, and outputs the electrical signal to the angle detection unit 5. The camera 4 may be a camera using a CMOS (Complementary Metal Oxide Semiconductor) in addition to being configured as a CCD camera.

  The angle detection unit 5 performs binarization processing after converting the image captured by the camera 4 into a grayscale image, and obtains an edge image, and the edge obtained by the processing of the edge image acquisition unit 51 Projection conversion unit 52 that converts the coordinate system of the image into the coordinate system of the image of work device W as viewed from the side, and each link of work device W after the Hough transform of the converted image converted by projection conversion unit 52. The edge extraction unit 53 that extracts the edges of the boom 7, the arm 8, and the attachment 9, the relative angle θ 1 (see FIG. 7) of the boom 7 with respect to the swing body 3 from the edge extracted by the edge extraction unit 53, An angle calculation unit 54 is provided to obtain the relative angle θ2 and the relative angle θ3 of the attachment 9 with respect to the arm 8.

  First, the angle detection unit 5 acquires an image photographed by the camera 4 and calibrated by a calibration process for distortion caused by lens distortion or the like of the camera 4 and processed by the edge image acquisition unit 51. The edge image acquisition unit 51 converts an image captured by the camera 4 into a gray scale image expressed by, for example, 256 gradation luminance values, and further binarizes the image to obtain a binary image. Edge image processing is performed to obtain an edge image. When the image of the working device W shown in FIG. 3 taken by the camera 4 is processed by the edge image acquisition unit 51, an image represented only by the edges shown in FIG. 4 is obtained.

  The projection conversion unit 52 converts the coordinate system of the edge image obtained by the processing of the edge image acquisition unit 51 into the coordinate system of the side image when the working device W is viewed from the side. When the projection converter 52 processes the edge image shown in FIG. 4, the working surface of the boom 7, the arm 8, and the attachment 9 of the work device W, that is, the direction passing through the plane on which the boom 7, the arm 8, and the attachment 9 operate. The image shown in FIG. 5 viewed from the side is obtained. Note that even if the edge image is coordinate-converted, an image whose edge is indicated by a white line can be obtained. However, for convenience of explanation, in FIG. This is described as inversion, and the same applies to FIGS. 6, 7, 8, 9, and 14.

  In the projective conversion process of the projective conversion unit 52, it is not necessary to actually obtain an image, and it is only necessary to obtain coordinate information of the edge after conversion. Specifically, the projective transformation unit 52 processes the image coordinates captured by the camera 4 using a projective transformation matrix. This coordinate transformation matrix is obtained by projecting the working device W with the camera 4 in advance. A matrix may be obtained in advance.

  The edge extraction unit 53 extracts the edges of the boom 7, the arm 8, and the attachment 9 by Hough conversion of the edge image after the coordinate conversion. The edge extraction unit 53 first extracts an edge only for the boom 7. Subsequently, the relative angle θ1 of the boom 7 with respect to the swing body 3 is obtained from the edge of the boom 7 thus obtained by the processing in the angle calculation unit 54, and the posture specifying unit 6 specifies the posture of the boom 7. After the posture of the boom 7 is specified, the edge extraction unit 53 extracts the edge of the arm 8 based on the posture of the boom 7. Then, after the posture of the arm 8 is specified as described above, the edge extraction unit 53 extracts the edge of the attachment 9. That is, in this example, the angle detection unit 5 obtains the relative angle in order from the link close to the revolving structure 3 that is the end link of the movable member M, and when the posture is specified by the processing of the posture specifying unit 6, The relative angle of the link is calculated.

  Therefore, first, the edge extraction unit 53 extracts the edge of the boom 7. The boom 7 is connected to the swing body 3 so as to be swingable in the vertical direction, and the boom 7 is swingable to the swing body 3 about the connecting shaft 7a. Then, the lower edge E1 of the end of the boom 7 on the side of the connecting shaft 7a is always at a constant radius from the connecting shaft 7a by rotation about the connecting shaft 7a with respect to the swing body 3 of the boom 7, as shown by a thick line in FIG. It should be located away by R1. That is, the length of the perpendicular line hanging from the center of the connecting shaft 7a to the virtual line obtained by extending the edge E1 is always R1. Further, since the shooting range of the camera 4 is fixed, the position of the connecting shaft 7a is outside the shooting range and is a fixed position even if it is not shot. Even if it is in the coordinate system after the projective transformation, the coordinates are fixed. It is. Even if the connecting shaft 7a is not photographed from the image photographed by the camera 4, the position of the connecting shaft 7a that is the rotation center of the boom 7 can be known in advance from the positional relationship between the boom 7 and the revolving structure 3, and the connecting shaft 7a The coordinates after projective transformation are known. As shown in FIG. 7, when the x-axis and the y-axis are taken on the working surface of the boom 7, the height of the connecting shaft 7a is given by assuming that the intersection of the perpendicular line hanging from the connecting shaft 7a to the ground is the origin O. Since it is a design value and known, if the height is L0, the center coordinate of the connecting shaft 7a is (L0, 0). Even if a plurality of straight edges of the boom 7 are obtained by the Hough transform of the edge image after the projective transformation, the distance between the edges or the straight line obtained by extending these edges and the central coordinate of the connecting shaft 7a is the same. If an edge equal to the radius R1 is selected, the edge of the boom 7 can be extracted.

  As described above, the radius R1 is a design value, and an edge can be extracted using this design value. However, the center coordinate of the connecting shaft 7a and the radius R1 to the edge may be set by the following procedure. . First, the relative angle between the boom 7 and the revolving unit 3 is changed to obtain at least three images of the boom 7 taken by the camera 4, and the edge of the boom 7 after coordinate conversion is obtained from these three images. The inscribed circles of these three edges may be obtained, the radius of this inscribed circle may be set as the radius R1 for edge extraction, and the center coordinates of the inscribed circle may be set as the center coordinates of the connecting axis 7a. As described above, when the image captured by the camera 4 is processed and the center coordinates of the connecting shaft 7a and the radius R1 for edge extraction are set, the edge of the boom 7 can be extracted more precisely.

  Further, in this example, when the construction machine C is traveling or the revolving unit 3 and the work device W are being driven, the construction machine C vibrates and vibrations are transmitted to the camera 4. Then, the position of the boom 7 in the image in the case where the camera 4 that is vibrating is shooting the boom 7 with respect to the image in which the camera 4 is shooting the boom 7 without vibration may be offset. Therefore, a threshold value Δr1 is set for the radius R1, and as shown in FIG. 8, a range in which the distance from the center coordinate of the connecting shaft 7a to the edge or the extended line of the edge is set by the threshold value Δr1 with the radius R1 as the center. Select an edge within R1 ± Δr1. And the longest edge is extracted as the edge E1 of the boom 7 among the extracted edges. In this way, in this example, the edge whose distance from the center coordinate of the connecting shaft 7a to the edge is within the range R1 ± Δr1 set by the threshold value Δr1 around the radius R1 is extracted as the edge of the boom 7. Therefore, even if the camera 4 vibrates by absorbing the offset due to the vibration with the threshold Δr1, the edge of the boom 7 can be accurately extracted. Further, the edge extraction unit 53 extracts the longest edge as the edge of the boom 7 when there are a plurality of edges within the range R1 ± Δr1 whose distance to the edge is set with the threshold value Δr1 with the radius R1 as the center. . If the longest edge is extracted as the edge of the boom 7, it is possible to prevent erroneous extraction of the edge of the boom 7, and the edge of the boom 7 can be extracted more reliably. That is, when the processing of the edge extraction unit 53 described above is performed, the edge E1 of the boom 7 used for angle detection can be extracted with high accuracy.

Subsequently, the angle calculation unit 54 detects the relative angle θ1 of the boom 7 with respect to the revolving structure 3 from the edge E1 selected by the edge extraction unit 53. Specifically, as shown in FIG. 9, the angle calculator 54 obtains an angle θ1 ′ between the horizontal axis H of the image and the edge E1 when viewed clockwise. In FIG. 9, when the edge is extended, the height y and the width x in the image of the extended edge are obtained by the intersection of the extended edge and the edge of the image. Therefore, θ1 ′ is obtained from the height y and the width x. = Tan ⁻¹ (y / x) is calculated to obtain θ1 ′. The angle θ1 ′ is obtained as 0 degree when the edge is horizontal in the image with respect to the revolving unit 3. The edge E1 of the boom 7 is an edge at the lower end of the revolving structure 3 side, and a straight line connecting the connecting shaft 8a and the connecting shaft 7a that rotatably connects the boom 7 and the arm 8 is not parallel to the edge E1. Since the relative angle θ1 of the boom 7 with respect to the swing body 3 is an angle formed by the straight line and the swing body 3, the angle θ1 ′ is obtained, and then the angle θ1 ′ is converted to the relative angle θ1. The angle θ1 ′ and the relative angle θ1 are shifted by a predetermined angle difference and are design values. Therefore, the angle difference is known. If the angle θ1 ′ is known, the relative angle θ1 can be uniquely determined. In this example, the relationship between the angle θ1 ′ and the relative angle θ1 is tabulated, and the angle calculator 54 obtains the angle θ1 ′ and then obtains the relative angle θ1 with reference to the table, but the angle difference is known. Therefore, the relative angle θ1 may be obtained by adding an angle difference to the angle θ1 ′. The relative angle θ1 treats the angle at which the straight line connecting the connecting shaft 7a and the connecting shaft 8a is horizontal with respect to the ground as 0 degrees.

  The posture specifying unit 6 specifies the posture of the boom 7 by obtaining the center coordinates of the connecting shaft 8a from the relative angle θ1 of the boom 7 to the swing body 3 detected by the angle detecting unit 5 described above. The distance L1 from the connecting shaft 7a of the boom 7 to the connecting shaft 8a is known because it is a design value. Since the relative angle θ1 is detected by the angle detection unit 5, assuming that the center coordinates of the connecting shaft 8a are (x2, y2) on the operating surface of the boom 7, the known center coordinates of the connecting shaft 7a. (L0, 0). Then, x2 = L0 + L1 · cos θ1, and y2 = L1 · sin θ1. Therefore, the posture specifying unit 6 can determine the center coordinates of the connecting shaft 8a by specifying the posture of the boom 7 using the relative angle θ1 and the distance L1. When the connecting shaft 8a is obtained in this way, the edge extracting unit 53 of the angle detecting unit 5 performs the same process as the process of extracting the edge of the boom 7 using the center coordinates of the connecting shaft 8a, and the edge of the arm 8 is obtained. Is detected. In addition, the attitude | position specific part 6 may obtain | require not only the center coordinate of the connection axis | shaft 8a but the gravity center coordinate of the boom 7. FIG. Since the distance from the center of gravity of the boom 7 to the connecting shaft 7a is a design value and is known, it can be obtained in the same manner as the center coordinates of the connecting shaft 8a.

  The edge extraction unit 53 extracts the edge of the arm 8 using the center coordinates of the connecting shaft 8a. The arm 8 is connected to the boom 7 so as to be swingable in the vertical direction, and the arm 8 is swingable to the boom 7 about the connecting shaft 8a. The lower end edge E2 of the end of the arm 8 on the side of the connecting shaft 8a is always at a constant radius R2 from the connecting shaft 8a by the rotation of the arm 8 around the connecting shaft 8a with respect to the boom 7 as shown by the thick line in FIG. Located just away. In other words, the length of the perpendicular line hanging from the center of the connecting shaft 8a to the virtual line obtained by extending the edge E2 is always R2. Therefore, similarly to the process of detecting the edge of the boom 7, the edge extraction unit 53 extends these edges or the edges even if a plurality of straight edges of the arm 8 are obtained from the edge image after the Hough transform. The edge of the arm 8 can be extracted by selecting an edge whose distance from the straight line obtained in this way and the center coordinate of the connecting shaft 8a is equal to the radius R2. As for the central coordinates and radius R2 of the connecting shaft 8a used in this processing, three or more images obtained by changing the relative angle between the arm 8 and the boom 7 are acquired as described above. A tangent circle may be obtained and set. In this example, similarly to the previous case, the threshold value Δr2 is set for the radius R2 so that the edge E2 can be extracted even if the edge due to the vibration of the camera 4 is offset in the image. Therefore, an edge is selected in which the distance from the center coordinate of the connecting shaft 8a to the edge or the extended line of the edge is within the range R2 ± Δr2 set by the threshold Δr2 with the radius R2 as the center.

When there are a plurality of edges selected in this way, the edge length, the distance between the edge or the extension line of the edge and the center coordinate of the connecting shaft 8a and the radius R2, the distance between the edge end and the center coordinate of the connecting shaft 8a The edge E2 is extracted by evaluating with three measures of distance. Specifically, for each edge, the longer the edge length, the better the score, the smaller the shift amount, the better the score, and the shorter the distance to the edge, the better the score, the total of these scores The edge having the highest number of points is extracted as the edge E2. Thus, if the evaluation by scoring is performed and the edge E2 of the arm 8 is extracted, the edge E2 of the true arm 8 can be extracted with high accuracy. Note that the edge E2 of the arm 8 may be extracted by the same process as the edge extraction of the boom 7 without performing the evaluation by scoring. The edge extraction unit 53 extracts the lower end of the edge E1 ₂ of nearby boom 7 of the connecting shaft 8a.

Then, the angle calculating unit 54 detects the relative angle θ2 of the arm 8 from the edge E1 ₂ edge E2 and the boom 7 of the arm 8 with respect to the boom 7. Specifically, the angle calculating unit 54, as shown in FIG. 9, the edge E2 and the edge E1 ₂ is a straight line, a angle of both at the intersection of both, as viewed from the edge E1 ₂ clockwise An angle θ2 ′ formed by both is obtained. Since the edge E2 and the edge E1 ₂ coordinates and slope data are obtained in Figure 9, from the information .theta.2 'is obtained. Angle .theta.2 'is the angle of the edge E2 of edge E1 ₂ and the arm 8 of the boom 7, in this embodiment, the edge E2 is connecting shaft 8a and the connecting shaft 9a for rotatably connecting the arm 8 and the attachment 9 not parallel to the straight line connecting the bets, the edge E1 ₂ are not parallel even line connecting the connection shaft 7a and the connecting shaft 8a. Therefore, the relative angle θ2 of the arm 8 with respect to the boom 7 is an angle formed by a straight line connecting the connecting shaft 9a and the connecting shaft 8a and a straight line connecting the connecting shaft 8a and the connecting shaft 7a. After that, the angle θ2 ′ is converted into the relative angle θ2. The angle θ2 ′ and the relative angle θ2 are shifted by a predetermined angle difference and are design values. Therefore, the angle difference is known, and if the angle θ2 ′ is known, the relative angle θ2 can be uniquely determined. In this example, the relationship between the angle θ2 ′ and the relative angle θ2 is tabulated, and the angle calculator 54 obtains the angle θ2 ′ and then obtains the relative angle θ2 with reference to the table, but the angle difference is known. Therefore, the relative angle θ2 may be obtained by adding an angle difference to the angle θ2 ′.

  When the relative angle θ2 is obtained in this way, the posture specifying unit 6 determines the center coordinates of the connecting shaft 9a from the relative angle θ2 and specifies the posture of the arm 8. The distance L2 from the connecting shaft 9a of the arm 8 to the connecting shaft 8a is known because it is a design value. Since the relative angle θ2 is detected by the angle detection unit 5, assuming that the center coordinate of the connecting shaft 9a is (x3, y3) on the operating surface of the arm 8, the known center coordinate of the connecting shaft 8a Let (x2, y2). Then, x3 = x2 + L2 · cos (θ1 + θ2) and y2 = y2−L2 · sin (θ1 + θ2). Therefore, the posture specifying unit 6 can determine the center coordinates of the connecting shaft 9a by specifying the posture of the arm 8 using the relative angle θ2 and the distance L2. In addition, the posture specifying unit 6 obtains center coordinates of a connecting shaft 10 a that rotatably connects the arm 10 and the lever 10 for driving the attachment 9 to the arm 8. Note that the posture specifying unit 6 may obtain not only the center coordinates of the connecting shaft 9 a but also the center-of-gravity coordinates of the arm 8. Since the distance from the center of gravity of the arm 8 to the connecting shaft 8a is a design value and is known, it can be obtained in the same manner as the central coordinates of the connecting shaft 9a.

When the center coordinates of the connecting shaft 10a are obtained, the edge extracting unit 53 extracts the edge of the attachment 9 in order to obtain the relative angle θ3 between the attachment 9 and the arm 8 using the center coordinates of the connecting shaft 10a. In this example, when the relative angle θ3 is obtained, an edge image before projective transformation is used. In this case, the attachment 9 is a bucket, and the edge extraction unit 53 extracts the upper and lower edges E3 ₁ and E3 ₂ of the attachment 9 as shown by bold lines in FIG.

Subsequently, the angle calculation unit 54 first obtains vertical distances H2 and H3 from the connecting shaft 10a to the edges E3 ₁ and E3 ₂ to detect a relative angle θ3 of the attachment 9 with respect to the arm 8. Angle calculating unit 54, the distance H2 of the connecting shaft 10a and the edge E3 _1, for the combination of the values of the distance H3 of the the connecting shaft 10a and the edge E3 _2, relative angle θ3 is in one-to-one relationship, these The relative angle θ3 is obtained from the distances H2 and H3. The length of the attachment 9 is known, and if the distances H2 and H3 in the vertical direction with respect to the connecting shaft 10a are obtained, the relative angle θ3 of the arm 8 of the attachment 9 can be known. Further, in this example, the attachment 9 is a bucket and the upper end outer shape is circular when viewed from the side, so that the attachment 9 can be connected even if the posture is changed so that the relative angle θ3 changes with respect to the arm 8. in some cases the shaft 10a and the edge E3 ₁ distance H2 of the upper end of the attachment 9 is not changed. On the other hand, the distance H3 of the edge E3 ₂ of the lower end of the connecting shaft 10a and the attachment 9 with changes in posture so that the relative angle θ3 is changed with respect to the attachment 9 arm 8 is always changing. However, the attachment 9, for example, a tilted 30 degrees to the pivot side from vertically downward, in the vertically downward and tilted 30 degrees in the counter-pivot side edge E3 ₂ of the lower end is located the same height. Therefore, when detecting the relative angle θ3 only the lower end edge E3 ₂ distance H3 of the attachment 9, do not know is inclined to the or counterclockwise pivoting side attachment 9 is inclined to the pivot side. Therefore, in this example, the relative angle θ3 is obtained from the two vertical distances H2 and H3 from the connecting shaft 10a to the edges E3 ₁ and E3 ₂ , so when the attachment 9 changes its posture and the relative angle θ3 changes. Can be detected accurately. In the case where the attachment 9 is not a bucket and the relative angle θ3 can be detected by extracting both edges of the attachment 9 and the arm 8 as in the detection process of the relative angle θ2 between the arm 8 and the boom 7, A process similar to the process for detecting the relative angle θ2 of the boom 7 may be performed. Thus, a straight edge E3 ₃ lateral upper end of the bucket attachment 9 in Fig. 6, may be obtained relative angle θ3 seeking these angle by extracting an edge E2 ₂ arms 8.

  When the relative angle θ3 is obtained in this way, the posture specifying unit 6 can specify the posture of the attachment 9 from the relative angle θ3, and can grasp the center of gravity position and the tip position of the attachment 9, for example. For example, when it is desired to obtain the tip coordinates of the attachment 9, the distance L3 from the tip of the attachment 9 to the connecting shaft 9a of the arm 8 is known because it is a design value. Since the relative angle θ3 is detected by the angle detection unit 5, assuming that the tip coordinate of the attachment 9 is (x4, y4) on the operating surface of the attachment 9, the known center coordinate of the connecting shaft 9a ( x3, y3). Then, x4 = x3 + L3 · cos (θ1 + θ2 + θ3) and y4 = y3−L3 · sin (θ1 + θ2 + θ3). Therefore, the posture specifying unit 6 can determine the tip coordinates by specifying the posture of the attachment 9 using the relative angle θ3 and the distance L3. The center-of-gravity coordinates of the attachment 9 can also be obtained in the same manner as the tip coordinates since the distance from the connecting shaft 9a to the center of gravity is known.

  In this way, the angle detection unit 5 obtains the relative angle θ1 of the boom 7 that is the link of the work device W that is the closest to the revolving structure 3 that is the end link in the movable member M to the revolving structure 3. When the posture specifying unit 6 specifies the posture of the boom 7, the angle detection unit 5 next obtains the relative angle θ <b> 2 with respect to the boom 7 of the arm 8 that is second closest to the revolving structure 3. Further, when the posture specifying unit 6 specifies the posture of the arm 8, the angle detection unit 5 next obtains a relative angle θ 3 with respect to the arm 8 of the attachment 9 farthest from the revolving structure 3. That is, the angle detection unit 5 detects the relative angle in order from the link of the working device W that is closest to the revolving structure 3 that is the end link in the movable member M.

  The configuration of the hardware resources of the angle detection device 1 in the present embodiment will be described. As shown in FIG. 11, the angle detection device 1 amplifies the camera 4 and the signal output from the camera 4 as hardware. An image interface 60 including an amplifier and an analog / digital converter, a CPU (Central Processing Unit) 61 that executes processing in the angle detection device 1, and a CPU 61 that performs processing in the angle detection device 1 described above. A ROM (Read Only Memory) 62 that stores an application to be executed, a program such as an operating system, and a RAM (Random Access Memory) 63 that provides a storage area to the CPU may be provided. The configuration of each part of the angle detection device 1 can be realized by executing an application program in order to perform the processing of the angle detection device 1 of the CPU 61.

  Although the configuration of the angle detection device 1 has been described above, the angle detection processing procedure of the angle detection device 1 will be described below based on an example of the flowchart of FIG.

  First, the angle detection device 1 first captures an imaging range with the camera 4 for angle detection (step S1). Next, the edge image processing and projective transformation described above are performed on the image photographed by the camera 4 to obtain an edge image (step S2).

  Subsequently, the edge of the boom 7 is extracted from the edge image (step S3), and the relative angle θ1 of the boom 7 with respect to the revolving structure 3 is obtained (step S4). Further, the center coordinates of the connecting shaft 8a are calculated from the relative angle θ1 (step S5).

  Further, the edges of the arm 8 and the boom 7 are extracted from the edge image (step S6), and the relative angle θ2 of the arm 8 with respect to the boom 7 is obtained (step S7). Then, the center coordinates of the connecting shaft 9a are calculated from the relative angle θ2 (step S8).

  Subsequently, the upper and lower edges of the attachment 9 are extracted from the edge image (step S9), and the relative angle θ3 of the attachment 9 with respect to the arm 8 is obtained (step S10). Further, the coordinates of the tip of the attachment 9 are calculated from the relative angle θ3 (step S11). As described above, it is possible to continuously detect the relative angles θ1, θ2, and θ3 by repeatedly performing the processing from step S1 to step S11 in a predetermined cycle.

  The angle detection device 1 configured in this manner photographs the other links (the boom 7, the arm 8, and the attachment 9) with the camera 4 attached to the end link (the swivel body 3) of the movable member M, and the photographing. The relative angles θ1, θ2, θ3 of the other links 7, 8, 9 are obtained from the obtained images. As described above, since the angle detection device 1 does not use sensors, the camera 4 can be installed in a safe place with a high degree of freedom without worrying about failure of the sensors. Further, in the angle detection device 1, since it is not necessary to collate the marker position data with the coordinates of the boom or the like when specifying the posture of the boom or the like, it is not necessary to store enormous map position data and a large capacity memory is not required. . Therefore, the cost of the angle detection device 1 can be reduced. In this example, the links 3, 7, 8, 9 are connected so as to be swingable. However, even if they are connected so as to be able to swing, the relative angle can be detected by the same image processing.

  In this example, since the angle detection device 1 can specify the posture of another link from the obtained relative angles θ1, θ2, and θ3, the center of gravity position of the link of the construction machine C to which the angle detection device 1 is applied is obtained. Thus, angle information necessary for ZMP calculation is obtained.

  Furthermore, in this example, the movable member M has three or more links 3, 7, 8, and 9, and the angle detection unit 5 obtains the relative angle θ1 of the link 7 closest to the end link 3, With respect to the second and subsequent links 8 and 9 from the link 3, the relative angles θ2 and θ3 are obtained based on the posture of the immediately preceding link 7 and 8 specified by the posture specifying unit 6.

  When the angle detection device 1 is configured in this manner, the posture immediately before the link 3 to the end of the relative angle detection target 8 is specified, and the relative angle θ2 in order from the link 7 closest to the end link 3 is specified. Is required. As described above, if the relative angles θ2 and θ3 of the links 8 and 9 are detected and the postures are specified in order for the other links 7, 8 and 9, even if the movable member M has many links, The relative angles θ1, θ2, and θ3 of the links can be easily detected.

  Further, in the angle detection device 1 of this example, the angle detection unit 5 processes the image captured by the camera 4 to detect the edges of the other links 7, 8, 9, and the relative angles θ 1, θ 2. , Θ3. Therefore, the angle detection device 1 configured in this way can detect the relative angles θ1, θ2, and θ3 from one image, not from a continuous image taken by the camera 4, so that the angle is detected in a timely manner without taking time. It can be detected.

  Further, in the angle detection device 1 of the present example, the movable member M is a work in which the end link is the revolving structure 3 of the construction machine C and the other link is rotatably connected to the revolving structure 3 of the construction machine C. As a device W, the camera 4 is installed in the cabin 3 a of the revolving unit 3. Since the camera 4 that captures an image necessary for relative angle detection is housed in the cabin 3a in this way, the camera 4 is protected from the external environment of the construction machine C. Therefore, in the angle detection device 1 of the present example, the camera 4 is not exposed to wind and rain, and is protected from flying stones and earth and sand during civil engineering work, so that stable relative angle detection is possible.

<Second Embodiment>
In the angle detector 80 of the second embodiment, as shown in FIG. 13, the structure and processing of the angle detector 81 is the structure of the angle detector 5 of the angle detector 1 of the first embodiment. Unlike other processes, other configurations and processes are the same. Therefore, in the following, the angle detection unit 81 having a different configuration will be described in detail, and detailed description of the same configuration will be omitted. The angle detector 80 is also applied to the construction machine C, and the camera 4 is installed in the cabin 3a of the revolving unit 3.

  The angle detection unit 81 converts the image captured by the camera 4 into a grayscale image, and then binarizes the binarized image by obtaining a binarized image. A projective transformation unit 83 that transforms W into a coordinate system of an image viewed from the side; a region extraction unit 84 that extracts a region where the connecting units 7a, 8a, and 9a are photographed from the binarized image after the projective transformation; The relative angle θ1 of the boom 7 with respect to the revolving structure 3 from the connecting portions 7a, 8a, 9a, 10a, and 10b extracted by the area extracting unit 84, the relative angle θ2 of the arm 8 with respect to the boom 7, and the relative angle θ3 of the attachment 9 with respect to the arm 8 are obtained. The angle calculation unit 85 to be obtained is provided. The connection shaft 10 a is a connection shaft between the lever 10 and the arm 8 that rotationally drives the attachment 9 with respect to the arm 8, and the connection shaft 10 b is a connection shaft between the attachment 9 and the lever 10.

  First, the angle detection unit 81 processes an image captured by the camera 4 and calibrated for distortion due to lens distortion or the like of the camera 4 by a calibration process by the edge image acquisition unit 51. The binarization processing unit 82 converts an image captured by the camera 4 into a grayscale image expressed by, for example, 256 gradation luminance values, and further binarizes the image to obtain a binarized image. .

  The projection conversion unit 83 converts the coordinate system of the binarized image obtained by the processing of the binarization processing unit 82 into the coordinate system of the side image when the working device W is viewed from the side. When the projection conversion unit 83 performs processing, the image shown in FIG. 14 is obtained as viewed from the side of the working device W in a direction that penetrates the working surfaces of the boom 7, the arm 8, and the attachment 9.

  In the projective conversion process of the projective conversion unit 83, it is not necessary to actually obtain an image, and it is only necessary to obtain coordinate information of the edge after conversion. Specifically, the projective transformation unit 52 processes the image coordinates captured by the camera 4 using a projective transformation matrix. This coordinate transformation matrix is obtained by projecting the working device W with the camera 4 in advance. A matrix may be obtained in advance.

  In this example, the region extraction unit 84 uses the connection bases 7a, 8a, 9a, 10a, and 10b as predetermined locations, and uses the feature-based matching such as MSER (Maximally Stable External Regions) to capture the region in which these are photographed. Extract by performing region extraction processing. The connecting shafts 7a and 8a are connecting pins for the revolving body 3 and the boom 7, and the boom 7 and the arm 8, and extract regions that match these characteristics. Using region extraction methods other than the MSER method. You may extract the area | region of the connection shafts 7a and 8a. Further, the connecting shaft 7a is a connecting shaft 7a between the revolving unit 3 and the boom 7, and the coordinates after projective transformation are known. Therefore, the camera 4 does not have to photograph the connecting shaft 7a.

  The distance L1 between the connecting shaft 8a and the connecting shaft 7a is, as shown in FIG. 14, the coordinates of the connecting shaft 7a is a fixed point when the image of the camera 4 is projectively transformed and does not move. It is known because it is constant and is a design value. Therefore, since the connecting shaft 8a exists on the circumference with the distance L1 as the radius from the center coordinate of the connecting shaft 7a, it is a region that coincides with the characteristics of the connecting shaft 8a at the time of region extraction, and from the connecting shaft 7a. An area where the distance is L1 is an area where the connecting shaft 8a is photographed. Further, in this example, when the construction machine C is traveling or the revolving unit 3 and the work device W are being driven, the construction machine C vibrates and vibrations are transmitted to the camera 4. Then, the position of the connecting shaft 8a in the image in the case where the vibrating camera 4 images the connecting shaft 8a may be offset with respect to the image in which the camera 4 images the connecting shaft 8a without vibration. Therefore, a threshold value ΔL1 is set for the radius L1, and an image region having a feature whose distance is within the range L1 ± ΔL1 from the center coordinates of the connecting axis 7a and coincides with the connecting axis 8a is extracted. Therefore, even if the camera 4 vibrates by absorbing the offset due to the vibration with the threshold value ΔL1, it is possible to accurately extract the region where the connecting shaft 8a is reflected in the image.

  The distance L2 from the center coordinate of the connecting shaft 8a to the connecting shaft 9a is known. Since the connecting shaft 9a exists at a position separated from the connecting shaft 8a by a distance L2, a region on the circumference of the radius L2 centering on the connecting shaft 8a is the connecting shaft 9a among regions where the characteristics of the connecting shaft 9a match. This is the area where the image is taken. Therefore, when the region of the connecting shaft 8a is extracted, the region extracting unit 84 obtains the center coordinates of the region of the connecting shaft 8a and is located at a distance L2 from the center coordinates and coincides with the connecting shaft 9a. If the area having the position is selected, the area where the connecting shaft 9a is photographed can be extracted. More specifically, a threshold value ΔL2 is set for the radius L2, and an image region having a feature whose distance is within the range L2 ± ΔL2 from the center coordinates of the connecting axis 8a and that matches the connecting axis 9a is extracted. For this reason, an offset portion due to the vibration of the camera 4 is absorbed by the threshold value ΔL2, and even if the camera 4 vibrates, the region where the connection axis 9a is reflected in the image can be accurately extracted. Furthermore, after the region extraction of the connecting shaft 9a is completed, the region extracting unit 84 subsequently extracts the imaged regions of the connecting shafts 10a and 10b. Even if the attachment 9 changes its posture with respect to the arm 8, the connecting shafts 10a and 10b remain at a constant distance with respect to the center coordinates of the connecting shaft 9a. Therefore, the region extraction unit 84 may extract the regions of the connecting shafts 10a and 10b by the same technique as the region extraction of the connecting shaft 9a with respect to the connecting shaft 8a and the region extraction of the connecting shaft 8a with respect to the connecting shaft 7a. Even in the region extraction of the connecting shafts 10a and 10b, a threshold may be set for the distance to absorb the offset of the positions of the connecting shafts 10a and 10b due to the vibration of the camera 4.

  Subsequently, the angle calculation unit 85 obtains a straight line that passes through the center coordinates of the connecting shaft 7a that is the rotation center of the boom 7 and the connecting shaft 8a that is the portion extracted by the region extracting unit 84, and from the inclination of the straight line with respect to the image. A relative angle θ1 between the swing body 3 and the boom 7 is detected. Further, the angle calculation unit 85 obtains a straight line that passes through the center coordinates of the connecting shaft 8a that is the rotation center of the arm 8 and the connecting shaft 9a that is the portion extracted by the region extracting unit 84, and the straight line and the connecting shafts 7a and 8a. The relative angle θ2 between the arm 8 and the boom 7 is detected by obtaining the angle formed with the straight line passing through the center coordinates. Then, the angle calculation unit 85 obtains a straight line that passes through the center coordinates of the connection shaft 10a that is the rotation center of the attachment 9 and the connection shaft 10b extracted by the region extraction unit 84, and the center coordinates of the straight line and the connection shafts 8a and 9a. An angle θ3 ″ formed by a straight line passing through the angle 8 is obtained. The angle θ3 ″ and the relative angle θ3 between the arm 8 and the attachment 9 are in a one-to-one relationship, and this relationship is tabulated in advance, and the table is calculated from the angle θ3 ″. If used, the relative angle θ3 can be obtained.

  In this example, the area extracting unit 84 is a connecting unit 7a that is a rotating shaft of the swing body 3 and the boom 7, a connecting unit 8a that is a rotating shaft of the boom 7 and the arm 8, and a rotating shaft of the arm 8 and the attachment 9. The region of the connecting portion 9a, the connecting shaft 10a that is the rotating shaft of the arm 8 and the lever 10, and the region of the connecting shaft 10b that is the rotating shaft of the attachment 9 and the lever 10 are extracted as predetermined locations, so that the region can be extracted at once. It is.

  When the area extraction unit 84 extracts other places as predetermined places instead of the connecting shafts 8a, 9a, 10a, and 10b, the processing may be performed in the same manner as in the first embodiment. That is, by extracting the region by the region extracting unit 84, the region of the part other than the connecting shaft 8a of the boom 7 separated from the connecting shaft 7a and the connecting shaft 7a is extracted. Next, the angle calculation unit 85 obtains the relative angle θ1 between the swing body 3 and the boom 7 from the coordinates of the region other than the connecting shaft 8a of the boom 7 that is separated from the connecting shaft 7a and the connecting shaft 7a, and specifies the posture. The center coordinate of the connecting shaft 8a in the boom 7 is obtained by the part 6. Since the angle between the straight line passing through the arbitrary part of the connecting shaft 7a and the connecting shaft 8a of the boom 7 and the horizontal axis of the image and the relative angle θ1 of the boom 7 of the revolving structure 3 has a one-to-one relationship. If this relationship is tabulated, the relative angle θ1 can be easily calculated. When the center coordinates of the connecting shaft 8a are obtained, the region extracting unit 84 can extract the region of the part from the known distance to the connecting shaft 8a and an arbitrary part of the arm 8, and the angle calculating unit 85 can connect the connecting shaft 8a. And the relative angle θ2 formed by the arm 8 and the boom 7 is obtained. There is a one-to-one relationship between an angle formed by a straight line passing through any part of the connecting shaft 8a and the arm 8, a straight line passing through any part of the connecting shaft 7a and the boom 7, and a relative angle θ2 between the boom 7 and the arm 8. Therefore, if this relationship is tabulated, the relative angle θ2 can be easily calculated. Further, when the relative angle θ2 is obtained, the posture specifying unit 6 is able to obtain the center coordinates of the connecting shafts 9a and 10a, and the region extracting unit 84 is a region of an arbitrary part of the lever 10 that is separated from the connecting shaft 10a by an arbitrary distance. The angle calculation unit 85 can obtain the relative angle θ3 between the attachment 9 and the arm 8 from the connecting shaft 10a and an arbitrary part of the lever 10. There is a one-to-one relationship between the angle formed by the straight line passing through the connecting shaft 8a and any part of the arm 8, the straight line passing through the connecting shaft 10a of the lever 10 and any part of the lever 10, and the relative angle θ3 between the arm 8 and the attachment 9. Therefore, if this relationship is tabulated, the relative angle θ3 can be easily calculated. In this way, if the region extraction region is determined in advance, the relative angles θ1, θ2, θ3 are obtained even if the region other than the connecting shafts 7a, 8a, 9a, 10a, and 10b is set as the region extraction region. The posture of each part can also be specified. When the regions to be extracted are connected shafts 7a, 8a, 9a, 10a, and 10b, the processing of the angle calculating unit 85 and the posture specifying unit 6 is not mixed, and the region extracting unit 84 is connected to the connecting shafts 7a, Region extraction of 8a, 9a, 10a, and 10b is possible.

  In this example, the projection conversion unit 83 converts the image coordinate system to a coordinate system viewed from the side of the work apparatus W, but the coordinate conversion by the projection conversion unit 83 may be omitted. Even if the coordinate conversion by the projection conversion unit 83 is not performed, the trajectory with respect to the connecting shaft 7a in the image taken by the camera 4 at an arbitrary position of the boom 7 to be extracted by the region extraction unit 84 is If the image is rotated with respect to 3 and captured, it can be grasped in advance. Therefore, even if the coordinate conversion is not performed by the projective conversion unit 83, the region to be obtained can be extracted by extracting the portion where the feature points coincide on the locus of an arbitrary part of the boom 7 by the region extraction unit 84. Since the angle formed by the straight line connecting this region and the connecting shaft 7a with the horizontal axis of the image has a one-to-one relationship with the relative angle θ1 between the boom 7 and the revolving structure 3, the angle calculation unit 85 is The relative angle θ1 can be obtained from the angle formed by the straight line and the horizontal axis. If the relative angle θ1 is obtained, the coordinates of the connecting shaft 8a in the image captured by the camera 4 are obtained. If the coordinates of the connecting shaft 8a are known, the arm 8 can be rotated when the arm 8 rotates relative to the boom 7. It can be seen what kind of trajectory the portion desired to be extracted by the region extraction unit 84 draws in the image. Therefore, the region extraction unit 84 can extract a region at an arbitrary position of the arm 8. As described above, even if the coordinate conversion by the projective conversion unit 83 is omitted, the relative angle θ1 between the boom 7 and the revolving structure 3 can be detected. If the relative angle θ1 can be detected, the relative angle θ2 between the arm 8 and the boom 7 is obtained. It can be detected. That is, if the region extraction and the angle detection are performed in order, the relative angles θ1, θ2, and θ3 can be obtained.

  Thus, when the relative angles θ1, θ2, and θ3 are obtained by the angle detection unit 81, the posture specifying unit 6 can specify the postures of the boom 7, the arm 8, and the attachment 9, as in the first embodiment. It is.

  The configuration of the hardware resources of the angle detection device 80 in the second embodiment is the same as that of the angle detection device 1 in the first embodiment, and the configuration of each part of the angle detection device 80 is the same as that of the CPU 61. The processing of the angle detection device 80 can be realized by executing an application program.

  The configuration of the angle detection device 80 has been described above. Hereinafter, the angle detection processing procedure of the angle detection device 1 will be described based on an example of the flowchart of FIG.

  First, the angle detection device 80 first captures an imaging range with the camera 4 for angle detection (step S21). Next, the above binarization process is performed on the image captured by the camera 4 to obtain a binarized image (step S22). Further, projective transformation is performed on the coordinates of the binarized image (step S23).

  Subsequently, the regions of the connecting axes 8a, 9a, 10a, and 10b, which are predetermined locations, are extracted from the binarized image after projective transformation (step S24), and the relative angles θ1, θ2, and θ3 are obtained (step S24). S25).

  Finally, the postures of the boom 7, the arm 8, and the attachment 9 are specified from the obtained relative angles θ1, θ2, and θ3 (step S26).

  As described above, the processing from step S21 to step S26 is repeatedly performed at a predetermined period, and the angle detection of the relative angles θ1, θ2, and θ3 and the postures of the boom 7, the arm 8, and the attachment 9 are continuously performed.

  In addition, when the location to extract the region is not the connecting shaft 8a, 9a, 10a, 10b, as shown in FIG. 15, after obtaining the binarized image in step S22, as in the flowchart of the first embodiment, A predetermined portion of the boom 7 is extracted (step S31), the relative angle θ1 of the boom 7 with respect to the revolving structure 3 is obtained (step S32), and the center coordinates of the connecting shaft 8a are obtained from the relative angle θ1 (step S33). ). Subsequently, an area of a predetermined portion of the arm 8 is extracted from the coordinates of the connecting shaft 8a (step S34), and a relative angle θ2 of the arm 8 with respect to the boom 7 is obtained (step S35). Then, the center coordinate of the connecting shaft 10a is obtained from the relative angle θ2 (step S36), the region of the predetermined location of the attachment 9 is extracted (step S37), and the relative angle θ3 of the attachment 9 with respect to the arm 8 is obtained. (Step S38), the coordinates of the tip of the attachment 9 are obtained from the relative angle θ3 (Step S39). In this way, even when the region to be extracted is not the connecting shaft 8a, 9a, 10a, 10b, the angle detection of the relative angles θ1, θ2, θ3 and the identification of the postures of the boom 7, the arm 8, and the attachment 9 are continued. Can be done.

  The angle detection device 80 configured in this manner photographs the other links (the boom 7, the arm 8, and the attachment 9) with the camera 4 attached to the end link (swivel body 3) of the movable member M, and the photographing. The relative angles θ1, θ2, θ3 of the other links 7, 8, 9 are obtained from the obtained images. As described above, since the angle detection device 80 does not use sensors, there is no fear of failure of the sensors, and the installation location of the camera 4 can be installed in a safe place with a high degree of freedom, and can withstand harsh use environments. Further, in the angle detection device 80, it is not necessary to collate the marker position data with the coordinates of the boom or the like when specifying the posture of the boom or the like, so that it is not necessary to store a huge amount of map position data and a large capacity memory is not required. . Therefore, the cost of the angle detection device 80 can also be reduced. In this example, the links 3, 7, 8, 9 are connected so as to be swingable. However, even if they are connected so as to be able to swing, the relative angle can be detected by the same image processing.

  Further, in this example, the angle detection device 80 can determine the posture of another link from the obtained relative angles θ1, θ2, and θ3, so the center of gravity position of the link of the construction machine C to which the angle detection device 1 is applied is obtained. Thus, angle information necessary for ZMP calculation is obtained.

  If the angle detection device 80 extracts the connecting shafts 7a, 8a, 9a, 10a, and 10b, which are the rotation shafts of the links 7, 8, and 9 as regions determined in advance, the postures of the links 7, 8, and 9 are extracted. Relative angles θ1, θ2, and θ3 can be obtained without specifying. Even in this example, the movable member M has three or more links 3, 7, 8, 9, and the angle detection unit 5 determines the relative angle θ 1 of the link 7 closest to the end link 3. The relative angles θ2 and θ3 are obtained for the second and subsequent links 8 and 9 from the end link 3 based on the posture of the immediately preceding link 7 and 8 specified by the posture specifying unit 6. Therefore, even in this angle detection device 80, as in the angle detection device 1 of the first embodiment, even when the movable member M has a large number of links, the relative angles θ1 and θ2 of all the links. , Θ3 can be easily detected.

  Further, in the angle detection device 80 of the present example, the angle detection unit 81 processes the image captured by the camera 4, and other links 7, 8, 9 are determined in advance from the image captured by the camera 4. Then, a straight line connecting the part and the rotation centers 7a, 8a, 10a in the other links 7, 8, 9 is obtained, and relative angles θ1, θ2, θ3 are obtained based on this straight line. Therefore, the angle detection device 80 configured as described above can detect the relative angles θ1, θ2, and θ3 from one image, not from a continuous image taken by the camera 4, so that the angle is detected in a timely manner without taking time. It can be detected.

  Further, even in the angle detection device 80 of the present example, the movable member M is an operation in which the end link is used as the revolving structure 3 of the construction machine C and the other link is rotatably connected to the revolving structure 3 of the construction machine C. As a device W, the camera 4 is installed in the cabin 3 a of the revolving unit 3. Since the camera 4 that captures an image necessary for relative angle detection is housed in the cabin 3a in this way, the camera 4 is protected from the external environment of the construction machine C. Therefore, in the angle detection device 80 of the present example, the camera 4 is not exposed to wind and rain, and is protected from flying stones and earth and sand during civil engineering work, so that stable relative angle detection is possible.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

DESCRIPTION OF SYMBOLS 1,80 ... Angle detection apparatus, 3 ... Revolving body (terminal link), 3a ... Cabin, 4 ... Camera, 5, 81 ... Angle detection unit, 6 ... Posture specification Part, 7 ... boom (other link), 8 ... arm (other link), 9 ... attachment (other link), C ... construction machine, M ... movable member, W ... Working equipment,

Claims (6)

A camera that is attached to the end link among the movable members having a plurality of links connected in series so as to be relatively rotatable, and is capable of photographing other links or all links other than the end link;
An angle detection device comprising: an angle detection unit that detects a relative angle between adjacent links based on an image captured by the camera. The angle detection device according to claim 1, further comprising a posture specifying unit that specifies a posture of the other link with respect to the link at the end based on the relative angle detected by the angle detection unit. The movable member has three or more links,
The angle detector
Determining the relative angle of the link closest to the end link;
For the second and subsequent close links from the end link, the relative angle is obtained based on the posture of the link immediately before specified by the posture specifying unit.
The angle detection device according to claim 2. The said angle detection part processes the said image image | photographed with the said camera, detects the edge of said other link, and calculates | requires the said relative angle. Angle detection device. The angle detection unit extracts a predetermined location of the other link from the image captured by the camera, obtains a straight line connecting the location and the rotation center of the other link, and based on the straight line The angle detection device according to any one of claims 1 to 3, wherein the relative angle is obtained. The movable member is a working device in which the end link is a revolving body of a construction machine and the other link is rotatably connected to the revolving body of the construction machine,
The angle detection device according to any one of claims 1 to 5, wherein the camera is installed in a cabin of the revolving structure.

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