JP3101801B2 - Abnormal inspection method of optical measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality inspection method for inspecting an optical measuring apparatus for measuring a cross section and a position of a work by using a light cutting method.

[0002]

2. Description of the Related Art Conventionally, as an optical measuring device of this kind,
According to Japanese Utility Model Application Laid-Open No. 63-27813, a slit light source for irradiating a slit light to a measuring head mounted on a moving mechanism such as a robot and an imager obliquely intersect the optical axis of the imager with the light plane of the slit light. The workpiece is irradiated with slit light in a state where the measuring head is moved to a position facing a predetermined measurement site of the work, and a light cut image of the work is taken by an image pickup device so that a cross section of the work is mounted. What measures a shape and a position is known.

[0003]

The coordinate system used as a reference for measurement by the optical measuring device is a coordinate system which is stationary with respect to the measuring head and is determined from the positional relationship between the slit light source and the image pickup device. If the measurement head is misaligned due to an abnormality or the measurement head is deformed due to contact with the workpiece, etc., the relative positional relationship between the slit light source and the imager may be deviated. Measurement cannot be performed correctly. The present invention
In view of the above, an abnormality inspection method for inspecting the presence or absence of an abnormality to prevent a measurement error from occurring, and for determining whether the abnormality has occurred in either the moving mechanism or the measuring head. The challenge is to provide

[0004]

Means for Solving the Problems In order to solve the above problems,
The present invention provides a measuring head mounted on a moving mechanism such as a robot, in which a slit light source for irradiating slit light and an imager have a predetermined positional relationship such that the optical axis of the imager is oblique to the optical surface of the slit light. The workpiece is irradiated with slit light while the measuring head is moved to a position facing a predetermined measurement site on the workpiece, and a light cut image of the workpiece is captured by an image pickup device to measure the cross-sectional shape and the position of the workpiece. An abnormality inspection method for an optical measuring device as described above, wherein a reference mark and a reference member extending in a predetermined direction are arranged in a predetermined positional relationship with respect to a moving mechanism, and the measurement head is mounted on the imaging device. The slit on the optical surface of the slit light perpendicular to the optical axis is positioned so as to be parallel to the extension direction of the gauge member at a position facing the gauge mark, and in this state, the gauge mark is positioned by the imager. Image of the mark that appears on the screen of the imager The presence / absence of abnormality is determined based on the presence / absence of displacement from the reference position, and when it is determined that there is an abnormality, the measuring head is positioned in such a manner that the light surface of the slit light is orthogonal to the extending direction of the reference member. In this state, the target point member is irradiated with slit light, and the target point member is imaged by the image pickup device, and the displacement of the light cut image of the target point member appearing on the screen of the image pickup device from the reference position. And determining whether the abnormality has occurred in the moving mechanism or the measuring head based on the correspondence between the mark and the displacement of the mark image from the reference position.

If the position of the image pickup device or the direction of the optical axis is deviated due to an error such as deformation of the measurement head due to an error in the measurement head due to an abnormality in the moving mechanism, the image pickup device is placed in a regular positional relationship with the reference mark. As a result, the mark image appearing on the screen of the image pickup device is shifted from the reference position. Therefore,
The presence or absence of an abnormality can be determined based on the presence or absence of this shift.

If the direction of displacement of the mark image from the reference position is a direction orthogonal to the direction in which the reference member extends, the reason for this is that the measurement head is misaligned due to a positioning error of the measurement head due to an abnormality in the moving mechanism. The position is shifted from the normal position facing the mark in the direction orthogonal to the extension direction of the reference point member, and the optical axis of the imager is shifted from the normal position to the direction orthogonal to the extension direction of the reference point member due to abnormality in the measurement head. That is, it is considered that the position of the slit light is shifted in the optical axis direction. If the cause is the former, even when the measuring head is positioned at a position facing the reference member, the measuring head is displaced in the direction orthogonal to the direction in which the reference member extends, so that the light-section image can be measured from the reference position to the reference point. It is displaced in a direction orthogonal to the direction in which the member extends. On the other hand, if the cause is the latter, the measuring head is positioned at a position facing the reference member, and when the slit light surface is in a posture perpendicular to the extending direction of the reference member, the optical axis of the slit light Since the plane orthogonal to the slit light plane including the slits extends along the direction in which the reference point member extends, the light cut image is shifted from the reference position by the shift of the optical axis of the image pickup device in the optical axis direction of the slit light. Displace in the direction.

When the direction of displacement of the measurement position of the gauge mark from the reference position is the direction in which the gauge member extends, the reason for this is that the measurement head is positioned at an error due to a positioning error of the measurement head due to an abnormality in the moving mechanism. The optical axis of the imager is misaligned from the normal position facing the mark in the direction in which the gauge point member extends, and the optical axis of the imager is misaligned from the normal position in the direction orthogonal to the optical axis of the slit light due to an abnormality in the measurement head. It is thought that there is. If the cause is the former, the position of the light-cut image itself almost coincides with the reference position only by shifting the light-cut portion of the reference member in the direction in which the mark-member extends, but if the cause is the latter, light-cut The image is displaced in a direction perpendicular to the optical axis of the slit light, that is, in a direction perpendicular to the extending direction of the reference member.

Therefore, when the direction of displacement of the light-section image with respect to the reference position is a direction orthogonal to the direction in which the reference member extends,
If the direction of displacement of the mark image from the reference position is a direction orthogonal to the direction in which the marking member extends, it is determined that an abnormality has occurred in the moving mechanism, and the direction of displacement of the mark image from the reference position is the position of the marking member. When it is in the extending direction, it can be determined that an abnormality has occurred in the measuring head.

If a mark is formed on the mark member, measurement of the mark image and measurement of the light-section image can be performed without moving the measuring head much, thereby improving the efficiency of inspection. . Also, at least two gauge members are provided extending in a direction orthogonal to each other, and the measurement of the position of the gauge mark and the measurement of the light section image of the gauge member are performed for each gauge member. If this is the case, the accuracy of the inspection can be further improved, which is advantageous.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a measuring station provided in the middle of an automobile body assembly line. Robots 1 serving as moving mechanisms are arranged on both right and left sides of the station, and a measuring head 2 is attached to the robot 1. The mounting accuracy of the vehicle body A is measured by measuring the position of a hole formed in the vehicle body A, which is a work, and measuring a cross section of a predetermined portion such as a roof side rail portion or a pillar portion of the vehicle body A.

The robot 1 has a robot body 11 provided on a base 10 elongated in the front-rear direction and movable back and forth, and an elevating frame 12 supported on the robot body 11 so as to be movable up and down.
And an orthogonal coordinate type robot having a robot arm 13 elongated in the left-right direction supported on the lifting frame 12 so as to be able to move left and right. The robot arm 13 has a U-axis as shown in FIG. , V-axis and W-axis three-axis wrist 14
The measuring head 2 was attached via the.

As shown in FIGS. 3 to 5, the head frame 20 of the measuring head 2 includes a slit light source 21 composed of a slit laser for irradiating slit light and a spot light source 22 composed of a spot laser for irradiating spot light. , CC
First and second two imagers 23 ₁ , 2 each comprising a D camera
3 ₂ and is attached. 23a in the figure is each imager 2
3 ₁ and 23 ₂ lenses.

The two imagers 23 ₁ and 23 ₂ are connected to the two imagers 23
_1, 23 ₂ of the optical axis are mutually arranged in a positional relationship as oblique. Here, both the imaging device 23 _1, 23 ₂ of the origin 0 to the intersection of the optical axis, Z-axis to the optical axis of the first imaging unit 23 _1, both imager 2
3 _1, 23 X-axis coordinate axes orthogonal to the Z axis on the plane containing the _second optical axis and the axis perpendicular to the Z axis and the X axis consider spatial coordinate system with the Y axis, the slit light source 21, the slit It is mounted in the head frame 20 via the sleeve 21a so that the light surface SP of light (hereinafter referred to as a slit light surface) is oblique to the Z axis at the origin 0 and coincides with a surface perpendicular to the XZ plane. The spot light source 22 is provided with both imagers 23 ₁ and 23 _2.
The optical axis of the spot light is attached to the head frame 20 via the bracket 22a such that the optical axis of the spot light obliquely intersects the XZ plane at the origin 0 on a plane perpendicular to the XZ flat axis in the middle of the optical axes.

In front of the slit light source 21, a head frame 2
A light-shielding body 21c that regulates the irradiation range of the slit light is provided via a cylindrical support 21b attached to the lens. The support 2b that matches the slit light plane SP is provided on the support 21b.
A slit-shaped through-hole 21d is formed along the generatrix of 1b, and a light-shielding body 21c is attached to the tip of the support 21b so as to protrude radially outward from the light-transmitting 21d.
Thus, the extra slit light is not reflected by the inner surface of the support 21b, is incident on the light shield 21c through the through hole 21d and is shielded, and the irradiation range of the slit light is the light shield 21c.
Is surely restricted to a predetermined range defined by

On the side of the measuring station, first and second two reference members 3 ₁ and 3 ₂ are arranged in a predetermined positional relationship with respect to the robot 1, and the measurement of the vehicle body A is started. Before performing the measurement, the measurement of the gauge members 3 ₁ and 3 ₂ is performed as described later to check whether the robot 1 is abnormal or the measuring head 2 is abnormal.
After that, the position of the hole of the vehicle body A carried into the measuring station and the cross-sectional measurement of a predetermined portion of the vehicle body A are measured to measure the assembly accuracy of the vehicle body A.

At the time of hole measurement, as shown in FIG. 6, the measuring head 2 is moved to a predetermined measurement position facing the hole B of the vehicle body A and positioned, and the spot light from the spot light source 22 is applied to the vehicle body A. by irradiation with both an imager 23 _1, 23 ₂ images the vehicle body a. Then, the image data of both the imaging device 23 _1, 23 ₂ and transmitted to the image processing circuit 4, the imager 23 _1,
The center coordinates of the screen of the image of the hole B which appear in 23 ₂ of the screen is measured to determine the center position of the hole portion b in the space coordinate system from these center coordinates on the principle of triangulation.

[0017] To detail this, projected onto the XY plane of the spatial coordinate system described above is imaged by the first imaging unit 23 _1, also orthogonal in the origin 0 to the optical axis of the second imager 23 ₂ the coordinate axis on the XZ plane as X 'axis, when projected onto the X'Y plane is imaged by the second imaging unit 23 _2, the imager 2
3 _1, 23 ₂ in FIG. 7 the center point to the origin corresponding to the origin 0 on the screen (a) (b) in as shown X, X 'of the vertical corresponding to the horizontal x-axis and the Y-axis corresponding to the axis when taking the y-axis, x and y coordinates of the first screen of the imager 23 ₁ will be indicative of a horizontal distance and a vertical distance from the origin 0 on the XY plane, the second imaging unit 23 ₂ of the screen X and y coordinates are X'Y
It represents the horizontal distance and the vertical distance from the origin 0 on the plane. Here, considering the center point M of the hole B, the image of the projected points m ₁ to the XY plane of the point M which is the first reference imager 23 ₁ hole on the first screen of the imager 23 ₁ become a central point of b _1, horizontal distance and a vertical distance from the origin 0 of the point m ₁ becomes x-coordinate m ₁ x and y-coordinates m ₁ y point m ₁ on a first imager 23 ₁ screen Similarly projection point m ₂ to the second imager 23 of M ₂ points relative to the X'Y plane becomes the center point of the image b ₂ of the hole on the second screen of the imager 23 _2, point horizontal distance and a vertical distance from the origin 0 of m ₂ is the x-coordinate m ₂ x and y-coordinate m ₂ y point m ₂ on the screen of the second imager 23 _2. And point M
Equations of projection line e ₂ of the equations of projection lines e ₁ to the first imager 23 ₁ of the line of sight of the XZ plane with determined from m ₁ x, to the second imager 23 ₂ of the line of sight of the XZ plane to the point M with respect to Are obtained by coordinate transformation based on m ₂ x, and the two projected lines e ₁ and e ₂
X and MX of point M in the spatial coordinate system as the intersection of
The coordinates MZ are calculated. Also, m ₁ y and the Y coordinate M of the point M
The ratio to Y is the distance L between the origin 0 and the first imager 23 _1.
And a line parallel to the X axis including the intersection and the first imager 23 ₁
, And this distance is represented by L-MZ, so that MY can be calculated by the following equation: MY = m ₁ y · (L−MZ) / L.

When measuring the cross section of a predetermined measurement site such as the roof side rail portion of the vehicle body A, the measuring head 2 is moved to the position shown in FIG.
As shown in the figure, the slit light source 21 is moved to a predetermined measurement position facing the measurement site of the vehicle body A for positioning, and the slit light source 21 irradiates the vehicle body A with the slit light and the first imager 23 ₁ The image of the vehicle body A is captured and the image data is transmitted to the image processing circuit 4.

[0019] Since the first imager 23 ₁ for imaging the radiation S of the slit light on the surface of the vehicle body A from an oblique direction, the first screen of the imager 23 _1, as shown in FIG. 9, the slit light plane An optical cut image s having a shape corresponding to the cross-sectional shape of the measurement part of the vehicle body A when the measurement part of the vehicle body A is cut by the SP appears. Light section image s in the illustrated example has become a Ku-shape having a maximum portion s ₁ of the x-axis direction corresponding to the corner portion A ₁ of the measurement site, in this case, the maximum point maxima s ₁ is squaring If you can clearly identify,
The shape and position of the measurement site can be measured based on this maximum point. However, you are impossible unambiguously identify the maximum point with a radius to maximum section s ₁ when marked with rounded the corners A ₁ of the measurement site.

Therefore, in this case, for the maximum part s ₁ , y
A plurality of windows WD are set for the image portions located on one side and the other side in the axial direction, respectively, and the positions of the image centroids in each of these windows WD are measured. The equation is calculated as an image line representing the light cut image s on the side, and the coordinates of the intersection Q between the image line on one side in the y-axis direction and the image line on the other side in the y-axis direction are obtained from the above equation. The cross section of the measurement site is measured as an alternative to the maximum point. Here, the equation of the slit light plane SP in the XYZ spatial coordinate system is known,
Further, on the screen of the x of the first imager 23 ₁ gaze equations intersection Q for the point on the XY plane corresponding to the intersection Q, it can be determined from the y-coordinate, the slit light plane SP of the line of sight
By calculating the spatial coordinates of the intersection with respect to, the position of the measurement site in the spatial coordinate system can be obtained.

[0021] Incidentally, when the measurement site is the S-shaped cross-section having a surface A ₃ which is valley folded with respect to the surface A ₂ continuous with the corner portion A _1, the irradiation range of the slit light in phantom in FIG. 8 When extends to the surface a ₃ as shown, the reflected image r by reflection image R of the radiation of the slit light on the surface a ₃ caught on surface a ₂ appear on the screen, enters the reflection image r in the window W of the above light The equation of the image line representing the cut image s cannot be calculated correctly,
A measurement error occurs. Therefore, in this embodiment, to restrict the irradiation range of the slit light by providing a light shield 21c as described above, the slit light is prevented from being irradiated to the surface A ₃ of the valley fold side of the measurement region as shown in FIG. 4, the reflection The occurrence of measurement errors due to the image r is prevented.

Further, by measuring the cross section in the same manner as above, the vehicle body A
Can also be measured. Although using the first imaging unit 23 ₁ upon sectional measurement in the above embodiment, since the slit light plane SP is obliquely intersects for the second imaging unit 23 ₂ of the optical axis, the second imager 23 _The cross-section measurement may be performed using ₂ .

The positioning accuracy of the robot 1 in the three orthogonal directions by the robot body 11, the lifting frame 12, and the robot arm 13 can be easily ensured by increasing the supporting rigidity of these members. Almost no positioning error occurs. On the other hand, since the weight of the V-axis drive unit 14v, the W-axis drive unit 14w, and the weight of the measuring head 2 act as an unbalanced load on the U-axis and the V-axis of the wrist 14, they are incorporated into the U-axis drive unit 14u and the V-axis drive unit 14v. The phase determination accuracy of the U-axis and the V-axis may be deviated due to tooth skipping of the harmonic reducer. Since the measuring head 2 is attached to the U-axis and the V-axis with a large inter-axis distance,
Due to the inaccuracy of the phase determination accuracy of each axis, the measuring head 2 generates a large positioning error, and it becomes impossible to secure the accuracy of the hole measurement and the cross-section measurement described above.

Further, the measuring head 2 may be deformed due to contact with a vehicle body or the like while the measuring head 2 is moving. When the optical axis of the imaging unit 23 _1, 23 ₂ is displaced in the X-axis direction and Y axis direction by the deformation of the measuring head 2, since the spatial coordinate system defined on the basis of the optical axis is mad, also in this case the measurement Accuracy cannot be ensured. Therefore, using the gauge member 3 _1, 3 ₂ described above, U-axis and the robot 1 abnormalities such V axis phase determination precision of deviation, imager 23 _1, 23 ₂ of the measurement such as displacement of the optical axis head 2 Of the vehicle A is measured only when there is no abnormality.

[0025] Each gauge member 3 _1, 3 _2, as shown in FIG. 10, is inclined with respect to the horizontal plane at an angle and equiangular in the first imaging unit 23 ₁ of the optical axis with respect to the slit light plane SP (Z-axis) It is composed of a substrate portion 30 and end plate portions 31 at both ends,
First the gauge member 3 _1, as shown in FIG. 11, and parallel to the U-axis, and the second the gauge member 3 ₂ placed on the first the gauge member 3 ₁ orthogonal direction. Also, a reference mark 32 made of a circular hole was formed on the substrate 30 of each of the reference members 3 ₁ and 3 ₂ . The circular hole is provided with a taper that expands inward so that the light reflected from the inner peripheral surface of the circular hole does not blur the outline of the image of the reference mark 32.

At the time of the abnormality inspection, the reference mark 3 formed on the first reference member 31 is _{first set} with the W axis being vertical.
2 the first imager 23 ₁ is positioned by moving the measuring head 2 to the first inspection position as positive against (the state of FIG. 10 and FIG. 11 (a)). At this time, a line on the slit optical surface SP orthogonal to the Z axis, which is the optical axis of the first imager 23 ₁ , that is, Y
Axis is parallel to the first extending direction of the gauge member 3 _1.

Next, by irradiating a spot light from the spot light source 22 for imaging the gage marks 32 in the first imager 23 _1. In this case, the mark image appearing in the first imager 23 ₁ of the screen, as shown in FIG. 12 (a), the deviation in the X-axis direction of the deviation and the first imager 23 ₁ of the optical axis of the U-axis is present shift in the x-axis direction, deviation or displacement in the first imager 23 ₁ in the Y-axis direction of the optical axis of the V-axis there deviates in the y-axis direction. Then, when the center point of the mark image is displaced from the reference position cp, it is determined that there is an abnormality.

Next, by rotating the W axis by 90 °, FIG.
As shown in (b), the slit light surface SP is the first reference point member 3.
Orthogonal to the _first extension direction, XZ plane is set to be parallel to the first the gauge member 3 ₁ in the extending direction. First the gauge member 3 ₁ is irradiated with the slit light from the slit light source 21 in this state is captured by the first imaging unit 23 _1. In this case, the first imager 23 ₁
The light section image appearing on the screen of, as shown in FIG. 12 (b), the deviation in the X-axis direction of the first imager 23 ₁ of the optical axis there is misalignment in the x-axis direction, and deviation of the U-axis first shift in the y-axis direction when the shift in the Y-axis direction of the optical axis of the imaging device 23 ₁ is present, where, measuring the displacement from the reference position qp bending point photocleavage image corresponding to the upper end of the edge of the substrate portion 30 I do. Incidentally, even if there is deviation of the V-axis, since the deviation of the angle range usually occurs where the measuring head 2 is moved parallel to the first the gauge member 3 ₁ in the extending direction, first the gauge member by the slit light 3 ₁ However, only the light-section of the image changes, but the position of the light-section image on the screen does not change.

[0029] Table 1, deviation of U-axis and V-axis, and abnormalities such X-axis direction and the Y-axis direction of the deviation of the first imager 23 ₁ of the optical axis, the displacement direction from the reference position of the mark image, 6 shows a relationship between a light-section image and a displacement direction from a reference position. In the table, a case where there is an abnormality or displacement is indicated by △, and a case where there is no abnormality or displacement is indicated by-.

[0030] As is clear from Table 1, the correspondence between the displacement direction of the mark image and the displacement direction of the light-section image of the type 4 and the type 9 and that of the type 5 and the type 7 correspond to each other. Correspondence between the displacement direction of the image and the displacement direction of the light-section image is different from each other, and from this correspondence, types 1 to 3, 6, 8, and 10 are obtained.
For, the cause of the abnormality can be determined.

[0031] When performing position measurement and a cross-sectional measurement of the substrate portion 30 of the gauge marks 32 of the above as to first the gauge member 3 ₁ side, then the measurement head 2 second the gauge member 3 ₂ side Go to
Position and measurement of the second the gauge member 3 ₂ gauge marks 32 formed on, a cross-section measurement of the second the gauge member 3 _second substrate portion 30, the gauge of the first the gauge member 3 ₁ side as described above The measurement of the position of the mark 32 and the measurement of the cross section of the substrate unit 30 are performed in the same procedure.

[0032] Here, the mark image captured by the second the gauge member 3 ₂ side is displaced in the x-axis direction in the X-axis direction of the deviation of the deviation and the image pickup device 23 ₁ of the optical axis of the V-axis, the U axis Madness and imager 23 ₁
Is displaced in the y-axis direction due to the displacement of the optical axis in the Y-axis direction. Also,
Photocleavage image, x in X-axis direction of the deviation of the optical axis of the imaging unit 23 ₁
Axially displaced, the deviation and the image pickup device 23 ₁ of the V axis of the optical axis Y
Displaced in the y-axis direction due to axial displacement.

[0033] Then, the relationship between the second the gauge member 3 and the displacement direction of the mark image and the light-section image of a _two-side abnormality is as shown in Table 2 below.

[0034] As is clear from Table 2, the correspondence between the displacement direction of the mark image and the displacement direction of the light section image of the type 4 and the type 7 and the relationship of the displacement direction of the light section image respectively correspond to the type 4 and the type 9, respectively. the displacement direction of the displacement direction and light section image and the corresponding relations each other are different and the type 1～3,6,8,10 from the counter relationship by measurement in the second the gauge member 3 ₂ side The cause of the abnormality can be determined.

Furthermore, the measurement displacement corresponding relationship between the displacement relationship and type 5 and type 7 Type of 4 and type 9 was identical to the second the gauge member 3 ₂ is measured at the first the gauge member 3 ₁ side in and mutually different, therefore, the overall judgment of the measurement result in the measurement result in the second the gauge member 3 ₂ side of the first the gauge member 3 ₁ side, the type 4,5,7,9 be The cause of the abnormality can be determined. In addition, U-axis deviation, V-axis deviation, imager 23 ₁
When three or more abnormalities among the four abnormalities of the optical axis shift in the X-axis direction and the optical axis shift in the Y-axis direction occur at the same time, both the mark image and the light section image are on the x-axis and the y-axis. displaced in the direction, but distinguished from the type 10 is not attached, when three or more abnormality occurs overlap, the optical axis of the imaging unit 23 ₁ is displaced in at least one axial direction of the X-axis and Y-axis Therefore, the measurement head 2 needs to be replaced, and by performing measurement again after the replacement of the measurement head 2, it can be determined whether or not the U-axis or V-axis is out of order.

When the measuring head 2 is deformed, it is most likely that the measuring head 2 will be displaced.
Since an optical axis of the image pickup device 23 ₁ in the above Examples were measured displacement of the mark image and the light-section image by the first imaging unit 23 _1, the mark image and the light-section image by the second imaging Symbol 23 ₂ May be measured together. Further, both imagers 2
Similarly to the hole measurement described above, the center position of the gage mark 32 in the spatial coordinate system is obtained from the mark images of 3 ₁ and 23 ₂ , and the upper end of the substrate unit 30 is obtained from the light-cut images of the image pickup devices 23 ₁ and 23 ₂ . The position of the edge in the spatial coordinate system may be determined, and the cause of the abnormality may be determined from the correspondence between the displacement of the center position and the displacement of the edge position. Further, even in the case of using the measuring head 2 of cross section measured only omitting the second imager 23 ₁ can determine the presence and cause of the abnormality in the same manner as in the above embodiment.

[0037]

As is apparent from the above description, according to the present invention, it is possible to determine the presence or absence of an abnormality, so that it is possible to prevent a measurement error of a work from occurring beforehand, and to determine whether the abnormality is caused by either the moving mechanism or the measuring head. It is also possible to determine whether the error has occurred, so that a post-measure can be easily performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a vehicle body measuring station provided with an optical measuring device for performing an abnormality inspection according to the present invention.

FIG. 2 is a perspective view showing a wrist and a measuring head of a robot as a moving mechanism.

FIG. 3 is a plan view of a measuring head.

FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a diagram showing the principle of position measurement of a hole.

FIGS. 7A and 7B are diagrams showing screens of first and second image pickup devices;

FIG. 8 is a perspective view showing the positional relationship between the slit light source and the first image pickup device with respect to the vehicle body when measuring the cross section of the vehicle body.

FIG. 9 is a diagram showing a screen of a first image pickup device.

FIG. 10 is a diagram showing a positional relationship between a measurement head and a reference member when capturing a reference mark.

FIGS. 11A and 11B are perspective views showing the movement of a measuring head at the time of an abnormality inspection.

12A is a diagram illustrating a displacement of a mark image, and FIG. 12B is a diagram illustrating a displacement of a light-section image.

[Explanation of symbols]

1 robot (moving mechanism), second measuring head 21 slit light source, 23 _1, 23 ₂ imager 3 _1, 3 ₂ the gauge member, 30 substrate 32 gauge mark

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-359583 (JP, A) JP-A-5-346307 (JP, A) JP-A-63-153412 (JP, A) JP-A-3-353 249510 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01B 11/00-11/30 102

Claims (4)

(57) [Claims] 1. A measuring head mounted on a moving mechanism such as a robot, a slit light source for irradiating slit light and an imager are positioned at a predetermined position such that the optical axis of the imager obliquely intersects the optical surface of the slit light. With the measuring head moved to a position facing a predetermined measurement site on the work, the work is irradiated with slit light, and a light cut image of the work is captured with an imager to measure the cross-sectional shape and position of the work An abnormality inspection method for an optical measuring device, comprising: placing a reference mark and a reference member extending in a predetermined direction in a predetermined positional relationship with respect to a moving mechanism; Is positioned at a position facing the gage mark in such a posture that the line on the optical surface of the slit light orthogonal to the optical axis of the slit light becomes parallel to the extending direction of the gage mark member. Image of the camera The presence or absence of an abnormality is determined based on the presence or absence of displacement from the reference position of the laser image, and when it is determined that there is an abnormality, the measuring head is placed in a posture in which the light surface of the slit light is orthogonal to the extending direction of the reference member. It is positioned at the position facing the reference point member, and in this state, the reference point member is irradiated with slit light, the target point member is imaged by the imager, and the reference position of the light cut image of the reference point member appearing on the imager screen. Determining whether an abnormality has occurred in the moving mechanism or the measuring head based on the correspondence between the displacement from the reference position and the displacement of the mark image from the reference position. . 2. When the displacement direction of the light-section image with respect to the reference position is a direction orthogonal to the extension direction of the reference point member, the displacement direction of the mark image from the reference position is perpendicular to the extension direction of the reference point member. When the direction is the direction, it is determined that the abnormality has occurred in the moving mechanism, and when the direction of displacement of the mark image from the reference position is the extending direction of the reference member, it is determined that the abnormality has occurred in the measuring head. The method for inspecting an abnormality of an optical measuring device according to claim 1. 3. The method according to claim 1, wherein a mark member having a mark is used. 4. At least two reference members are provided extending in a direction orthogonal to each other, and the measurement of the position of the reference mark and the measurement of the light-cut image of the reference member are performed for each reference member. The method for inspecting an abnormality of an optical measuring device according to claim 3, wherein: