JP2000018921A - Dimension measuring method and apparatus thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure an actual dimension of flaws and crack defects without measuring a distance between a camera and a structural surface, by making a camera approach to a narrow part through remote scanning. SOLUTION: This measuring apparatus comprises a dimension measuring apparatus main body 1, provided with a camera picking-up the surface image of an object to be inspected, an irradiating means which is installed in the apparatus main body 1 and casts a slit light 22 formed of parallel light having a known length on the surface of the object 90, an image processing means which simultaneously picks up the images of the slit light 22 and a crack defect 91 with the camera, takes in an image of the camera and performs various kinds of image processings, and a displaying means which displays an image 51 containing a crack defect image 91A and a slit light image 22A from the image processing means. By setting the slit light image 22A as the reference, actual dimensions of the crack defects 91 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the actual size of an inspection object from image information.

[0002]

2. Description of the Related Art Visual inspection using a camera is performed in various fields, such as on a production line of various products and at the time of periodic inspection of a structure. The actual dimensions of defects such as flaws and cracks are measured.

The actual size of a defect or the like is obtained from the relationship between the size of the inspection object and the defect image in the camera image, the camera viewing angle in the actual environment, the attitude of the camera, and the distance between the camera and the inspection object.

The cameras used in these visual inspections are:
Usually, it is mounted on a rail or track installed corresponding to the inspection object. Since the mechanism for driving the camera includes an angle detector, a distance sensor, and the like, the posture of the camera and the distance between the camera and the inspection object can be easily measured. Further, in a visual inspection in which the positional relationship between the camera and the inspection object does not change, the posture, position, and the like of the camera can be grasped in advance.

[0005] As a conventional visual inspection device for obtaining actual dimensions of a structure or a defect from an image obtained by a camera, there is, for example, a visual inspection device disclosed in JP-A-9-280828. This apparatus obtains an actual size from an image of a marker serving as a scale instead of a scale and an image of an inspection object displayed on a monitor. The length of the marker can be freely changed according to the object to be inspected, and the actual size can be easily measured. The marker displayed on the monitor is created based on an image obtained by photographing a scale attached to the inspection object in advance with a camera. Since the camera stably moves on the orbit set along the inspection object, it does not change if the camera attitude, camera position, and the like are grasped in advance.

[0006]

In recent years, remote visual inspection of narrow structures has been desired. Further, the inspection time must be shortened. For visual inspection of a remote constriction, the camera needs to be remotely approached to the confinement.

However, in the above-mentioned prior art, since the object to be inspected is a remote narrow portion, it is difficult to attach a scale, and it is impossible to display a marker instead of the scale. Furthermore, it is difficult to set up the camera track. If the orbit cannot be set up, the measured values of the attitude and position of the camera will be inaccurate.

Further, even if the track is mounted, the work time for mounting and removing the track is added in addition to the inspection time, so that the entire inspection time is increased.

It is an object of the present invention to provide a measuring method and an apparatus which can quickly measure the actual dimensions of an inspection object even when the work of attaching a scale is difficult.

[0010]

According to the present invention, there is provided a camera for photographing the surface of a structure on which an object to be inspected is provided, and a camera having a known length on the surface of the structure on which the object to be inspected is present. Irradiating means for irradiating the irradiating object, and image processing means for taking in image information from the camera and performing a process of representing the irradiating object and the inspection object as images in a desired format on an image display means. A measuring device is used, and an irradiation object of a known length irradiated onto the surface of the structure where the inspection object is present, and the inspection object are simultaneously photographed, and based on the image of the irradiation object in the photographed image. And a dimension measuring method for determining the actual dimensions of the inspection object is executed.

As another means, a camera for photographing the surface of the structure where the inspection object exists, and a plurality of cameras which are on the surface of the structure where the inspection object exists and have a known interval in the field of view of the camera. A spot light irradiating means for irradiating the surface with an irradiating object by irradiating a spot light, and a process of capturing image information from the camera and presenting the irradiating object and the inspection object as images in a desired format on an image display means An image processing means for performing, a dimensional measurement device provided with, each irradiation object by a plurality of spot light irradiated at a known interval on the surface of the structure where the inspection object exists, and the inspection object Are simultaneously photographed, and a dimension measuring method for obtaining an actual dimension of the inspection object based on an interval between the images of the irradiation objects in the photographed image is performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of a dimension measuring apparatus according to a first embodiment of the present invention. FIG. 1 shows a state in which a crack defect 91 to be inspected on the surface of the inspection object 90 is dimensionally measured using the dimension measuring apparatus main body 1.

The surface of the inspection object 90 is irradiated with slit light 22 by light parallel to the camera optical axis from the main body 1 of the dimension measuring device. It is expressed as Camera image 5 at that time
1 includes a crack defect image 91A which is an image of the crack defect 91.
And a slit light image 22A which is an image of the irradiation object. Although not shown, the dimension measuring apparatus main body 1 includes a mechanism for remotely scanning a camera and an illumination facility for illuminating the inspection object 90.

FIG. 2 shows a detailed view of the dimension measuring apparatus according to the first embodiment of the present invention. The dimension measuring device includes a CCD camera 10, a spot laser light emitter 20, a collimator lens 23, a reflecting mirror 24, a half mirror 25, and an image processing device 50.
And a television monitor 60. The spot laser light 21 emitted from the spot laser light emitter 20 is turned into slit light 22 by the collimator lens 23, refracted by the reflection mirror 24 and the half mirror 25, and parallel to the optical axis of the camera 10. Is irradiated.

The CCD camera 10, the spot laser light emitter 20, the collimator lens 23, the reflection mirror 24, and the half mirror 25 are relatively fixed to each other, and the slit light 22 is inspected in parallel with the optical axis of the camera 10. Object 9
0 is maintained so as to irradiate the surface.

The image processing device 50 takes in photographing information from the CCD camera 10 and performs image processing for displaying it on a television monitor 60 in a desired format. Further, the image processing device 50 calculates the length L of the crack defect image 91A where there is a luminance change from the surroundings based on the photographing information from the CCD camera 10.
m and the length 22A of the slit light image 22A are calculated as the length in the linear distance between both ends.

The image captured by the CCD camera 10 image-processed by the image processing device 50 is displayed as an image on a television monitor 60.

Reference numeral 11 denotes a camera field of view of the CCD camera 10. The mechanism for remotely scanning the image processing device 50, the television monitor 60, and the camera, and the controller (not shown) of the dimension measuring device main body are installed near a worker who is in a safe place away from the measurement position.

The parallel slit light image 22A and the crack defect image 91A are displayed on the television monitor 60. The procedure for measuring the actual size of the crack defect 91 will be described below.

The actual dimension length S of the slit light 22 is measured in advance. Since the light of the slit light 22 is a parallel ray and is irradiated orthogonally to the inspection object 90, the actual dimension length S is constant regardless of the distance of the dimension measuring apparatus main body 1 from the inspection object 90.

Next, as shown in FIGS. 1 and 2, the image processing device 50 calculates and calculates the length Sm of the slit light image 22A and the length Lm of the crack defect image 91A.

From these three values, the actual size of the crack defect L
Is determined by (Equation 1, L = S × Lm / Sm). Therefore, even if the distance between the dimension measuring device main body 1 and the inspection object 90 is unknown, the actual size of the crack defect can be easily obtained.

When the camera optical axis of the dimension measuring apparatus main body 1 and the inspection object 90 are orthogonal to each other, the left and right sizes a and b of the slit light image 22A from the monitor center as shown in FIG. Become equal. If they are not orthogonal, the sizes of a and b are not equal as shown in FIG. Thus, the posture of the camera is easily estimated from the slit light image 22A,
As much as possible, a state where the camera optical axis of the dimension measuring device main body 1 and the inspection object 90 are orthogonal to each other is maintained at the time of measurement, and accurate measurement is performed.

The second embodiment of the present invention is an example in which the first embodiment is partially changed. The changed portions will be described below, and the description of the same portions as the first embodiment will be omitted.

FIG. 4 shows an outline of a dimension measuring apparatus according to a second embodiment of the present invention. FIG. 4 shows a state where the size of the crack defect 91 on the surface of the inspection object 90 is measured by the size measuring device main body 1.

From the main body 1 of the dimension measuring device, spot laser beams 30 and 31 which are parallel to the optical axis of the camera are radiated on the surface of the inspection object 90 as an irradiation object. For this reason, the spot laser beams 30 and 31 can cause spots having higher luminance than the two surroundings to appear as irradiation objects on the surface of the inspection object 90.

The camera image 51 obtained by capturing these images includes a crack defect image 91A and a spot laser light image 30A.
And 31A are displayed.

FIGS. 5, 9 and 10 show detailed views of a dimension measuring apparatus according to a second embodiment of the present invention. The dimension measuring device is CC
D camera 10, spot laser light emitters 20A and 20
B, an adjusting mechanism 70 for adjusting the distance between the spot laser light emitters 20A and 20B, and the spot laser light emitters 20A and 20B.
Rotating mechanism 8 for rotating OB about the optical axis of camera 10
0, an image processing device 50, and a television monitor 60. The image processing device 50 takes in the photographing information from the CCD camera 10 and obtains a length Lm between both ends of the crack defect image 91A,
Similarly, it has a function of calculating an interval length Sm between the spot laser light images 31A and 30A as a length in a linear distance.

FIG. 9 shows the internal structure of the main body 1 of the dimension measuring apparatus. Posts 102 and 103 are fixed to a frame 101 of the main body 1 of the dimension measuring apparatus.
A horizontal support frame 104 having a circular cross section is fixed to the upper part of the camera, and a CCD camera 10 is installed on the right end of the support frame 104 so that the camera optical axis and the axis of the support frame 104 coincide.

At the intermediate portion of the support frame 104,
A rotation frame 106 is attached via a bearing 105 so as to be rotatable about the axis of the support frame 104. On the rotating frame 106, a slider 108 is formed by a groove 107 so that a slider 108 extends in the longitudinal direction of the rotating frame 106, that is, CC.
The combination is slidable in a direction orthogonal to the camera optical axis of the D camera 10 and the axis of the support frame 104.

The slider 108 includes a CCD camera 1
0 so that the irradiation direction B of the laser beam is parallel to the optical axis of the camera 0 or the axis of the support frame 104.
0A and 20B are fixed. A screw shaft 109 is screwed into the slider 108, and the screw shaft 109 is driven to rotate by a motor 110 provided at an end of the rotating frame 106. The screw shaft 109 causes the slider 108 to drive the spot laser light emitting devices 20 A and 20 B. It can slide while being supported. The motor 110 has a slider 108
An encoder 111 is provided to measure the amount of movement of the encoder.

The adjusting mechanism 70 for adjusting the distance between the spot laser light emitters 20A and 20B is configured as described above, and detects the amount of movement of the slider 108 by the encoder 111 to determine the distance between the spot laser light emitters 20A and 20B at a remote point. The operator controls the motor 110 from the
It is possible to make adjustments while monitoring the detection results of 11 at a remote location.

The spot laser emitters 20A and 20B
Is rotated about the optical axis of the CCD camera 10. The rotating frame 106 described above is rotated by the bearing 105, and the spot laser light emitters 20A and 20B mounted on the rotating frame 106 are simultaneously driven by the CCD camera 10. The mechanism rotates around the optical axis.

In order to control the rotation mechanism 80 from a remote location, a motor 112 capable of being controlled from a remote location is installed on the column 102, and a gear 113 fixed to a rotation output shaft of the motor 112 is connected to another gear 114. Bite.
The gear 114 is fixed to the rotating frame 106 such that the center of rotation coincides with the axis of the supporting frame 104. Therefore, when the motor 112 is started and controlled from a remote location, the rotational driving force of the motor 112 is increased by the gears 113 and 114.
To the rotating frame 106, and the rotating frame 106 can rotate. Rotating frame 106
In order to detect the rotation angle of the motor 112, an encoder is attached to the motor 112, and the amount of rotation of the motor 112 is detected by the encoder to estimate the rotation angle of the rotating frame 106.

The image processing device 50, the television monitor 60, and the controller (not shown) of the dimension measuring device main body 1 are installed near the workers as in the first embodiment. The spot laser beams 30, 31 emitted from the spot laser light emitters 20A, 20B are directly irradiated on the surface of the inspection object 90 in parallel with the optical axis of the CCD camera 10.

The image picked up by the CCD camera 10 is displayed on the television monitor 60 from the image processing device 50. 1
Reference numeral 1 denotes a camera field of view of the CCD camera 10. A spot laser light image 30A is displayed on the screen of the TV monitor 60.
And 31A, the crack defect image 91A is displayed on the same screen. The procedure for measuring the actual size of the crack defect is the same as in the first embodiment of the present invention, and the spot laser beam 30,
From the three values, using the actual dimension interval S of 31 and the interval Sm between the spot laser light images 30A and 30B obtained by the image processing device 50 and the length Lm of the crack defect image 91A,
The actual dimension L of the crack defect is expressed by the following equation: L = S × Lm / Sm
Determined by Therefore, even if the distance between the dimension measuring device main body 1 and the inspection object 90 is unknown, the actual size of the crack defect can be easily obtained.

The actual size of the crack defect 91 can be easily measured as in the first embodiment, even if the distance between the main body 1 of the dimension measuring device and the inspection object 90 changes. As in the first embodiment, the posture of the main body 1 of the dimension measuring device can be easily estimated by comparing the distance between the spot laser light images 30A and 31A from the center of the monitor.

The adjusting mechanism 70 includes the laser emitters 20A, 20A.
The interval of B can be adjusted, and the amount of movement can be detected by the encoder. The rotation mechanism 80 includes the laser emitters 20A and 20B and the adjustment mechanism 70,
This mechanism rotates the camera around the optical axis of the camera, and the rotation angle can be detected by the encoder. Adjustment mechanism 7
With the zero and rotation mechanism, the interval between the spot laser beams 30, 31 and the inclination angle of the straight line connecting the spot laser beams 30, 31 can be adjusted to the size and inclination of any crack defect. The dimensions can be measured, and the actual dimensions of the crack defect can be easily measured not only by the image processing device but also by the human eye.

For example, after the interval between the laser emitters 20A and 20B is set to the minimum known interval S1, the interval between the laser emitters 20A and 20B is increased and the spot laser beam 3 is increased.
Until 0 and 31 are applied to both ends of the crack defect image 91A, the interval between the laser light emitters 20A and 20B is widened to a state as shown in FIG. The state is confirmed while watching the image on the television monitor 60, and each laser light emitter 2 at the time of confirmation is confirmed.
The movement amount of each of 0A and 20B is known by observing the measurement value indicated by the encoder, the total of each movement amount is detected as a movement size S2, and S2 is added to S1 to determine the length of a straight line connecting both ends of the crack defect 91. Thus, the length is defined as the length of the crack defect 91.

When the crack defect 91 is inclined as shown in FIG. 6B, the inclination of a straight line connecting the laser light emitters 20A and 20B and the spot laser beams 30 and 31 is determined by the inclination of the crack defect 91. The length of the crack defect 91 is obtained by performing the measurement as described above after rotating to match the inclination.

FIG. 7 shows an outline of a third embodiment of the present invention.
As shown in FIG. 7, this is a dimension measuring device that irradiates the inspection object 90 with the cross slit light 28 with laser light parallel to the camera optical axis. Since the slit light is displayed as a reference length line in the vertical direction by the cross slit light 28 as compared with the first embodiment, the horizontal slit light 22 is used as the reference length line in the first embodiment. Similar to the measurement method, the accuracy of the measurement of the longitudinal crack defect is improved by using the longitudinal slit light as the line of the reference length for the measurement of the longitudinal crack defect.

The orientation of the main body 1 of the dimension measuring device can be obtained in two dimensions, horizontal and vertical. Note that the length of each side of the cross of the cross slit light 28 needs to be measured in advance using actual dimensions. Other configurations and operations are the same as those of the first embodiment.

FIG. 8 shows an outline of a fourth embodiment of the present invention.
In this embodiment, the cross slit light 28 of the third embodiment is replaced with four spot laser beams 30, 31, 32, and 33 whose irradiation positions are determined at positions corresponding to the ends of each side of the cross. . Compared with the third embodiment, since a collimator lens, a reflection mirror and a half mirror are not required, the mechanism of the apparatus is simplified, and the apparatus can be downsized. In the case of this embodiment, the image processing apparatus of the second embodiment is used, and the horizontal interval between the spot laser beams 30, 32 and the spot laser beams 31,
33 are obtained by the image processing apparatus. Then, the second distance is determined using the horizontal distance between the spot laser beams 30, 32 and the vertical distance between the spot laser beams 31, 33, which are measured and known in advance.
The same measuring method as in the embodiment is applied not only to the cracks in the horizontal direction but also to the cracks in the vertical direction, and it is possible to measure the dimensions of the cracks in both the horizontal and vertical directions.

In each of the above embodiments, the means for scanning the dimension measuring apparatus main body 1 equipped with a CCD camera at a remote narrow portion is not described. However, since the dimension measuring apparatus main body 1 of each embodiment does not need a track or the like. The size measuring device body 1 is mounted on any scanning mechanism such as a manipulator, a pole, and an underwater robot, and remote scanning is possible.

[0046]

According to the first and second aspects of the present invention,
Since it is not necessary to equip a measuring object with a scale or to use guide means such as rails to keep the distance between the measuring object and the main body of the dimension measuring device constant, it is a narrow place where conventional dimension measurement is difficult. However, it is possible to provide a method capable of quickly and accurately measuring the actual size of a crack defect or the like to be measured on the measurement object.

According to the third or fourth aspect of the present invention, the use of a guide means such as a rail for mounting a scale on the object to be measured or for keeping a constant distance between the object to be measured and the main body of the dimension measuring apparatus. Since it is not necessary, it is possible to provide an apparatus that can quickly and accurately measure the actual size of a crack defect or the like to be measured on a measurement target even in a narrow place where conventional dimension measurement is difficult.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a concept of a measuring operation state by a dimension measuring device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a dimension measuring device according to a first embodiment of the present invention.

FIGS. 3A and 3B show a change in camera image due to a change in camera posture according to the first embodiment of the present invention. FIG. 3A shows a case where the camera is not tilted in a horizontal plane, and FIG. Are shown in the case of a posture having an inclination of.

FIG. 4 is a perspective view showing a concept of a measuring operation situation by a dimension measuring device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a dimension measuring device according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of crack defect measurement when an adjusting mechanism and a rotating mechanism are used in a second embodiment of the present invention.

FIG. 7 is a configuration diagram of a dimension measuring device according to a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a dimension measuring device according to a fourth embodiment of the present invention.

FIG. 9 is a top view showing a detailed configuration of a main body of a dimension measuring device according to a second embodiment of the present invention.

FIG. 10 is a sectional view taken along the line AA of FIG. 9;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dimension measuring device main body, 10 ... CCD camera, 11 ... Camera view range, 20 ... Spot laser light emitter, 21 ...
Spot laser light, 22: slit light, 23: collimator lens, 24: reflection mirror, 25: half mirror, 3
0, 31: spot laser beam, 50: image processing device, 6
0: television monitor, 70: adjusting mechanism, 80: rotating mechanism,
90: inspection object, 91: crack defect, S: actual size of irradiated object, Sm: length of irradiated object in camera image, L: actual size of crack defect, Lm: crack defect in camera image Length, K…
Actual size conversion factor.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA22 AA23 AA49 FF01 FF04 FF23 FF26 FF67 GG04 HH03 HH04 HH05 JJ03 JJ26 LL04 LL12 LL50 QQ28 QQ31 SS02 SS13 2G051 AA83 AA90 AB02 EC21 0401 CB01A01 BA15 DA03 DA20 DB02 DC03

Claims (4)

[Claims] An object having a known length irradiated onto a surface of a structure in which an object to be inspected is illuminated and the object to be inspected are simultaneously photographed, and an image of the illuminated object in the photographed image is used as a reference.
A dimension measuring method for determining an actual dimension of the inspection object. 2. The object to be inspected is photographed simultaneously with each irradiation object by a plurality of spot lights illuminated at a known interval on the surface of a structure on which the object to be inspected is present, and the inspection object is included in the photographed image. A dimension measuring method for obtaining an actual dimension of the inspection object based on an interval between each image of each irradiation object. 3. A camera for photographing a surface of a structure on which an inspection object exists, and an irradiating means for irradiating an irradiation object of a known length on a surface of the structure on which the inspection object exists and a visual field range of the camera. A dimension measurement device comprising: an image processing unit that captures image information from the camera and displays the irradiation object and the inspection target as images in a desired format on an image display unit. 4. A camera for photographing the surface of a structure on which an inspection object is present, and a plurality of spot lights on the surface of the structure on which the inspection object is present and having a known interval in a field of view of the camera. Irradiating means for irradiating the surface with an irradiating object by irradiating a spot light; and an image for taking in image information from the camera and performing processing for displaying the irradiating object and the inspection object as images in a desired format on an image display means. And a processing unit.