JP2019056671A - Wall surface damage inspection device - Google Patents

Abstract

To provide a wall surface damage inspection device that can detect abnormality such as fine crack and the like without being affected by a wall surface characteristic such as a material, surface roughness or the like.SOLUTION: A wall surface damage inspection device comprises: measurement means 12 that arranges a laser light irradiation unit 14 projecting linear laser light to a wall surface 50 targeted for inspection, and an imaging unit 16 photographing a shape of the laser light projected to the wall surface 50, which are shifted by a prescribed angle θ around an axis in an extension direction of the laser light to be projected to the wall surface 50 with the axis in the extension direction thereof set as a base point; and computation means 18 that conducts image processing of calculating an amount change of a non-linear part of the projected laser light on the basis of a distance L from the wall surface 50 to the measurement means 12, and an arrangement angle θ between the laser light irradiation unit 14 and the imaging unit 16, preparing a concavity and convexity-shaped image of the wall surface 50, and preparing a wall surface state image cancelling out concavity and convexity based on a wall surface characteristic of the wall surface 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for inspecting damage such as cracks and floats existing on wall surfaces of various materials, such as concrete, bricks, and tiles, having different surface roughnesses.

  Conventionally, damages such as cracks and floats on the wall surface are determined by visual inspection of the entire wall surface using photographs, and by visual inspection, the part that is suspected of being damaged is confirmed by percussion and percussion diagnosis, and is drawn by sketching. It was done. However, these methods are analog, and a large proportion depends on the skill level of workers who perform photo judgment and the like.

  For this reason, the technique which can perform the damage inspection of a wall surface without depending on the skill level of an operator was calculated | required. Under such a background, a device disclosed in, for example, Patent Document 1 has been proposed as an apparatus for inspecting a wall surface for damage or abnormality. The apparatus disclosed in Patent Document 1 uses a laser ranging, a visible light camera, a laser imaging means, an infrared imaging means or the like, and an apparatus for inspecting and analyzing abnormalities such as cracks and floating on a wall surface in a tunnel It is.

  In the apparatus disclosed in Patent Document 1, surface space coordinates are created based on image data acquired through a visible light camera, a laser imaging unit, and the like, and the data acquired by the infrared imaging unit is analyzed in a complex manner. In this case, abnormalities such as surface floats and cracks are diagnosed.

  As a technique for measuring the shape of an object using laser light, for example, a technique disclosed in Patent Document 2 is known. The technique disclosed in Patent Document 2 is to project a line-shaped laser beam onto the surface of an object to be measured, and to capture the shape of the line-shaped laser beam with a visible light camera. By giving an angle to the relationship between the irradiation position of the laser beam and the imaging position of the visible light camera, the shape change of the laser beam that changes along the surface shape of the object is acquired, and by calculating this change, the object It is disclosed that surface shape data can be acquired.

JP 2004-347585 A JP 2011-191253 A

  The technique disclosed in Patent Document 1 seems to be a suitable means for detecting a large abnormality that causes a temperature change in a wide range of inspections such as in a tunnel formed of concrete. However, with such an inspection technique, the resolution is limited due to the relatively long distance to the measurement object, and it is difficult to detect minute cracks with a width of 0.2 mm. .

  Moreover, although the technique disclosed in Patent Document 2 can accurately detect the shape of the surface of the object to be measured, when this is applied to a wall surface, the wall surface characteristics such as the material and surface roughness are reduced. May also be detected, making it difficult to determine where the actual damage is.

  Therefore, the present invention aims to solve the above-described problems and provide a wall surface damage inspection apparatus capable of detecting abnormalities such as cracks without being affected by wall surface characteristics such as material and surface roughness. .

  In order to achieve the above object, a wall surface damage inspection apparatus according to the present invention includes a laser beam irradiation unit that projects a line-shaped laser beam onto a wall surface to be inspected, and a shape of the laser beam projected onto the wall surface. An imaging unit for imaging, a measuring unit arranged by shifting a predetermined angle around the extending direction axis with respect to an extending direction axis of laser light projected on the wall surface, and a distance from the wall surface to the measuring unit And calculating the amount of change of the non-linear portion of the projected laser beam based on the arrangement angle between the laser beam irradiation unit and the imaging unit, and creating an uneven shape image of the wall surface, The image processing apparatus includes an operation unit that performs image processing for generating a wall surface state image in which the unevenness based on the wall surface characteristics is canceled, and a display unit that displays the wall surface state image created by the operation unit.

  In the wall surface damage inspection apparatus having the above-described characteristics, the wall surface characteristics may be acquired by reading in advance a wall surface state of a portion determined to be normal on the wall surface. By having such characteristics, it is possible to obtain the unevenness characteristics of the wall surface itself to be inspected. Therefore, highly accurate data can be acquired as the wall surface characteristics.

  Moreover, in the wall surface damage inspection apparatus having the above-described features, the display unit may display an actual image captured by the imaging unit together with the wall surface state image. By having such a feature, it is possible to determine the presence or absence of damage such as cracks by comparing the wall surface state image with the actual image.

  According to the wall surface damage inspection apparatus having the above-described characteristics, it is possible to detect abnormalities such as cracks without being affected by wall surface characteristics such as material and surface roughness.

It is a block diagram which shows the structure of the wall surface damage inspection apparatus which concerns on embodiment. It is a block diagram which shows the side view form of a measurement means. It is a block diagram which shows the plane form of a measurement means. It is a figure which shows the scanning state of the wall surface made into a test object, and the mode of a crack. It is a figure which shows the mode of the uneven | corrugated shaped image produced based on the real image detected by scanning. It is a figure which shows the state which arranged the uneven | corrugated shaped image continuously according to a time series. It is a figure which shows the wall surface state image which canceled the unevenness | corrugation based on a wall surface characteristic. It is a figure which shows the structure of an example of the raising / lowering stand applicable to the wall surface damage inspection apparatus which concerns on embodiment.

  Hereinafter, embodiments of the wall surface damage inspection apparatus of the present invention will be described in detail with reference to the drawings. The following embodiment is a part of a preferred embodiment of the present invention, and even if a part of the configuration is changed within a range where the same effect as the embodiment shown below can be obtained, the present embodiment It can be regarded as a part of the invention.

[Device configuration]
As shown in FIG. 1, the wall surface damage inspection apparatus 10 according to the present embodiment is configured based on measurement means 12, calculation means 18, and display means 20. As shown in FIGS. 2 and 3, the measuring unit 12 includes at least a laser beam irradiation unit 14 and an imaging unit 16. 2 is a view showing a side view of the measuring means 12, and FIG. 3 is a view showing a plan view of the measuring means 12. As shown in FIG.

  The laser beam irradiation unit 14 is an element that projects a line-shaped laser beam onto the wall surface 50 to be inspected. For this reason, the laser beam irradiated from the laser beam irradiation unit 14 is irradiated in a fan shape with the light source as a base point. The imaging part 16 should just have an imaging range including the irradiation range of the projected laser beam at least. That is, it is only necessary that the reflected light of the laser light projected on the wall surface 50 can be received by the image sensor.

  The imaging unit 16 is arranged so as to have a predetermined inclination angle θ with respect to the laser beam irradiation unit 14. The inclination angle θ may be an angle around an axis with the extending direction axis P of the laser light as a base point. By arranging the laser beam irradiation unit 14 and the imaging unit 16 in this arrangement relationship, the imaging unit 16 captures an image of a state where the projected laser beam is deformed along the uneven shape of the wall surface 50. Is possible. Further, when the distance L to the wall surface 50 is constant, if the inclination angle θ is reduced, the unevenness depth (height) d of the detectable laser beam is increased, and if the inclination angle θ is increased, the detectable laser is obtained. The unevenness depth (height) d of light becomes small.

  The measuring means 12 having the laser beam irradiation unit 14 and the imaging unit 16 in such an arrangement form determines the distance from the wall surface 50 to be inspected to the laser beam irradiation unit 14 and the imaging unit 16, so that triangulation can be performed. By this method, it is possible to derive the depth (height) of damage caused by cracks or the like from the change in the unevenness indicated by the laser beam. Here, the distance L from the wall surface 50 to the laser beam irradiation unit 14 and the imaging unit 16 is basically the distance from the wall surface 50 to the light projecting element (light source) and the distance from the wall surface 50 to the light receiving (image receiving) element. However, it is also possible to recognize the distance from the lens as a base point by adding a calculation correction value.

  Note that the depth of damage that can be detected by such a method is a range in which the unevenness drawn by the laser beam can be captured. If the unevenness cannot be detected, for example, the concave portion becomes a shadow and the imaging unit 16 reflects. When light cannot be received, the depth of the unevenness may not be able to be guided.

  The calculation means 18 is an element for analyzing a two-dimensional image acquired via the measurement means 12 and outputting a control signal to the lifting platform 24 described later in detail. Here, the analysis of the two-dimensional image is a process for calculating the concavo-convex state of the wall surface 50 based on the two-dimensional image and determining whether or not there is damage such as a crack. An example of specific processing is as follows.

[Image generation processing]
First, the imaging unit 16 captures the shape of the line-shaped laser irradiated from the laser light irradiation unit 14 and projected onto the wall surface 50, and acquires an actual image. When the wall surface 50 has damage such as cracks or unevenness, a non-linear portion as shown in FIG. 5 appears in the line laser. The calculating means 18 calculates the amount of change in the non-linear portion from the number of pixels or the number of pixels and calculates the height (the amount of change in the Z-axis direction) based on the amount of change in the non-linear portion based on the principle of triangulation. By such processing, it is possible to detect the depth (height) of cracks and irregularities in the laser beam reachable range and in the imaging range by the imaging unit 16.

  Here, the distance L from the wall surface 50 to the laser light irradiation unit 14 and the imaging unit 16 is set to a relatively short distance, for example, 200 mm to 400 mm, preferably about 300 mm, so that the acquired image in the imaging unit 16 per unit width is obtained. Resolution can be increased. Therefore, even if the crack is a minute crack having a width of about 0.2 mm, it is possible to detect the uneven state caused by the crack. That is, the distance L may be determined on the basis of a distance at which the imaging unit 16 can obtain an arbitrary resolution.

  When the wall surface 50 to be inspected is made of brick as shown in FIG. 4, in addition to the crack indicated by the broken line A in FIG. 5, the joint portion generated between the bricks is indicated by the broken line B in FIG. As shown, it is detected as a recess. The detected image data of the laser beam is displayed as a concavo-convex shape image of the wall surface 50 on the display means 20 attached to the calculation means 18 in a form that is visible to the operator. The shape of the laser light is projected as two-dimensional data by the imaging unit 16, so that when the laser light is extended in the Y-axis direction, the unevenness change amount is acquired as a change in the X-axis direction. Is done. The calculation means 18 can calculate the amount of change in the Z-axis direction (depth direction) from this actual image by the principle of triangulation and display it on the screen.

  Acquisition of image data (actual image) by the imaging unit 16 and calculation of the amount of change in the non-linear portion are continuously performed according to the scanning time by the measuring unit 12. As shown in FIG. 6, the calculation means 18 continuously arranges the acquired laser beam image data or image data obtained by extracting the irregularities drawn by the laser beam from the image data on the same plane in a time series, and meshes the irregularities. Apply processing.

  In the present embodiment, as described above, when the imaging unit 16 cannot receive the reflected light of the laser beam, the depth of the recess cannot be detected. However, when the reflected light cannot be received, a defect portion is generated in the unevenness drawn by the laser light in the detection data (actual image) by the imaging unit 16. Such missing portions of the laser light may be complemented based on a predetermined algorithm, or may be simply determined as a recess. Here, complementing the missing part of the laser beam based on a predetermined algorithm is to complement the expected line shape based on, for example, the width of the missing laser beam and the inclination of the laser beam in the vicinity of the missing part. Anything can be used.

  In the present invention, it is only necessary to determine whether or not the wall surface 50 is damaged. Even if the depth of damage is unknown, the accuracy of the inspection itself is not affected.

[Wall characteristic processing]
At the same time as or before or after the mesh process described above, a process for canceling the unevenness due to the wall surface characteristics of the wall surface 50 to be inspected is performed to generate a wall surface state image (see FIG. 7). For example, in the case of a brick wall 50 as shown in FIG. 4, typical wall characteristics include unevenness due to joints. When the processing for canceling the unevenness due to the wall surface characteristics is performed on the continuously arranged image after the mesh processing shown in FIG. 6, as shown in FIG. 7, a wall surface state image in which only the concave portion due to the crack appears is generated. It is possible to determine whether or not there is damage such as cracks.

  The determination on the presence or absence of damage such as cracks may be made automatically based on a separately defined algorithm, but the wall surface state image displayed on the display means 20 in the form as shown in FIG. Based on this, the operator may make a determination.

  Further, the wall surface characteristics may be input in advance via the input means 22 attached to the calculation means 18 or the like. Further, the input of the wall surface characteristic may be a numerical value input, or the surface of the wall surface that has been determined to be normal in advance is read by the measuring means 12 so that the unevenness that approximates this is used as the wall surface characteristic. good.

  In addition to the uneven shape image and the wall surface state image, the display unit 20 can also display a real image of the wall surface 50 imaged by the imaging unit 16. This is because it is possible to determine the presence or absence of damage such as cracks with higher accuracy by comparing both the actual image and the wall surface state image.

[effect]
According to the wall surface damage inspection apparatus 10 having such a configuration, it is possible to detect abnormalities such as minute cracks without being affected by wall surface characteristics such as material and surface roughness.

[Elevator base]
The wall surface damage inspection apparatus 10 having such a configuration is configured such that the distance L from the wall surface 50 to the measuring means 12 (specifically, the laser beam irradiation unit 14 and the imaging unit 16) is kept constant, and the scanning direction (X-axis direction). Need to make a move to. For this reason, the wall surface 50 can be inspected smoothly by providing the measuring means 12 on the lifting platform 24 as shown in FIGS. 1 and 8, for example. The lifting platform 24 includes at least a lifting rail 26 and a lifting slider 28, and a transverse rail 30 and a transverse slider 32.

  The elevating rail 26 is a rail erected in the vertical direction with the base 34 as a base point, and is an element for moving the measuring means 12 in the wall surface damage inspection apparatus 10 in the Y axis direction, that is, moving up and down along the wall surface 50. is there. The elevating slider 28 is a slider that moves along the elevating rail 26, and can be configured so as to be bridged between the elevating rails 26 arranged to form a pair, for example. The raising / lowering operation of the raising / lowering slider 28 with respect to the raising / lowering rail 26 should just be the actuator 36 which receives a control signal from the calculating means 18. FIG. Here, the actuator 36 may be any driving means such as a motor, and more specifically, it may be a pulse control type motor such as a stepping motor. With such an actuator 36, it is possible to control the rotation operation based on a control signal from the calculation means 18. Further, the position of the elevating slider 28 can be controlled by detecting the rotational speed using an encoder (not shown).

  The actuator 36 may have a configuration (direct drive method) provided in the lift slider 28, or may have a configuration (indirect drive method) provided on the lift rail 26 (base 34) side. In FIG. 8, the actuator 36 is disposed on the lifting rail 26 side to reduce the weight of the lifting slider 28. This is because, with such a configuration, the lifting slider 28 can be driven even when the output of the actuator 36 is small.

  The traverse rail 30 is an element for moving the measuring means 12 in the wall surface damage inspection apparatus 10 along the wall surface 50 in the scanning direction (X-axis direction), and is preferably disposed on the lift slider 28. The traversing slider 32 is a slider that moves along the traversing rail 30 and is an element on which the measuring means 12 is mounted. The traversing operation of the traversing slider 32 is performed by an actuator 38 such as a motor as in the case of the lifting slider 28, and the position control may be performed by an encoder or the like.

  By providing the measuring means 12 in the lifting platform 24 having such a configuration, it is possible to execute an inspection of an arbitrary position (range) of the wall surface 50 in a range where each rail reaches. Moreover, you may make it provide the object detection sensor 40 in the lifting stand 24 of such a structure.

  The object detection sensor 40 is a sensor for detecting a structure such as a window frame, a pillar, or a wall (all not shown) existing on the wall surface 50. The object detection sensor 40 may be a non-contact type using a laser or the like, or may be a contact type using a switch or the like. Not only the structure but also the concave structure can be detected.

  By connecting the object detection sensor 40 having such a function to the calculation means 18, a detection signal from the object detection sensor 40 is obtained by the calculation means 18, and the object detection sensor 40 is a structure (if it is a contact type sensor). When contact is detected, if it is a non-contact type sensor, this can be determined when a structure such as an unevenness having a size exceeding a threshold value is detected. When the detection signal from the object detection sensor 40 is input, the calculation unit 18 stops the operation signal to the actuators 36 and 38 of the lifting platform 24 and the laser beam irradiation stop to the laser irradiation unit 14 of the measurement unit 12. Cancel control can be performed.

  In the above embodiment, it has been described that the measuring means 12 of the wall surface damage inspection apparatus 10 is provided on the lifting platform 24. However, it is possible to move the measuring means 12 while keeping the distance from the wall surface 50 to the measuring means 12 constant. If there is, the measuring means 12 may be moved manually. The measuring means 12 may be provided in a moving means that does not have a rail, such as a robot that can be attracted to the wall surface 50.

  In addition, when imaging of laser light by the imaging unit 16 is difficult due to the influence of light having a wavelength other than laser light, such as visible light, a filter that allows only light of an arbitrary wavelength to pass is provided. May be.

  In the above embodiment, the wall surface characteristics are described as being read by the measuring unit 12 in advance as to the state of the wall surface determined to be normal, but a database in which sample data based on the material of the wall surface 50 is collected, For example, a wall surface characteristic to be approximated may be selected from the database.

DESCRIPTION OF SYMBOLS 10 ......... Wall-surface damage inspection apparatus, 12 ......... Measurement means, 14 ......... Laser light irradiation part, 16 ......... Imaging part, 18 ......... Calculation means, 20 ......... Display means, 22 ......... Input means 24... Elevating frame 26... Elevating rail 28... Elevating slider 30... Traverse rail 32. 38... Actuator, 40... Object detection sensor, 50.

Claims (3)

A laser beam irradiating unit that projects a line-shaped laser beam onto a wall surface to be inspected, and an imaging unit that images the shape of the laser beam projected onto the wall surface, Measuring means arranged by shifting a predetermined angle around the extension direction axis from the extension direction axis,
Based on the distance from the wall surface to the measuring means and the arrangement angle between the laser beam irradiation unit and the imaging unit, the amount of change in the non-linear portion of the projected laser beam is calculated, and the unevenness of the wall surface An arithmetic means for creating a shape image and performing image processing to generate a wall surface state image in which irregularities based on the wall surface characteristics of the wall surface are canceled,
A wall surface damage inspection apparatus comprising: display means for displaying a wall surface state image created by the computing means.   The wall surface damage inspection apparatus according to claim 1, wherein the wall surface characteristic is acquired by reading in advance a wall surface state of a portion determined to be normal on the wall surface. The display means includes
The wall surface damage inspection apparatus according to claim 1, wherein an actual image captured by the imaging unit is displayed together with the wall surface state image.

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