JP7348025B2 - Inspection system and method - Google Patents

Description

The present invention relates to an inspection system and an inspection method .

For example, in order to maintain the operating rate of a structure such as an industrial machine, it is preferable to identify damaged locations in the structure at an early stage. By identifying damaged areas early, repairs can be made before the damage becomes large, and it is possible to prevent a significant drop in operating efficiency due to major repairs caused by large damage. Damage to structures occurs, for example, due to stress concentration in the structure. BACKGROUND ART A technology disclosed in Patent Document 1 is known in relation to stress measurement technology in structures.

Patent Document 1 discloses a first measurement step of measuring time-series infrared intensity distribution data using an infrared thermography as measurement data regarding the displacement distribution of an object to be measured, on which a spot pattern having different emissivity depending on the position of the surface is applied in advance. a calculation step of applying a digital image correlation method to the frames constituting the acquired time-series infrared intensity distribution data to obtain displacement amount data regarding the displacement distribution of the measured object with respect to the load application history; a second measurement step of measuring time-series infrared intensity distribution data as stress data for stress measurement using infrared thermography; and pixel-by-pixel distribution data of the time-series infrared intensity distribution data acquired in the second measurement step. A position correction method in infrared thermoelastic stress measurement is described, which includes a position correction step of converting the displacement data into distribution data for each coordinate in which the displacement is corrected based on the displacement amount data regarding the displacement distribution. .

JP 2007-205875 A (see especially claim 1)

By the way, in the first measurement step described in Patent Document 1, time-series infrared intensity distribution data of the object to be measured with a spotted pattern is acquired under the same load application conditions in thermoelastic stress measurement (see paragraph 0030). The spotted pattern is applied with black or gray spray paint (see paragraph 0028). For this reason, depending on the color of the structure, the speckled pattern stands out and the design of the structure deteriorates.

An object of the present invention is to provide an inspection system and an inspection method that can inspect a structure while maintaining its design.

The inspection system of the present invention includes a first member, which is disposed on the surface so that the surface of the first member is partially exposed, has a color similar to that of the first member, or is colorless and transparent, and has a deformation and a deformation. A plurality of thermophysical property values that are associated with a temperature change caused by a thermophysical property value that is different from that of the first member, and each of which is composed of the same color when the first member is of the same color as the first member. a second member; and performing image analysis based on a digital image correlation method using infrared images of the structure before and after deformation obtained by the imaging device. and an arithmetic processing unit including an image analysis unit that determines the amount of displacement of an arbitrary point on the surface of the structure due to deformation . Other solutions will be described later in the detailed description.

According to the present invention, it is possible to provide an inspection system and an inspection method that can inspect a structure while maintaining its design.

FIG. 1 is a schematic diagram showing an inspection system according to a first embodiment. FIG. 2 is an enlarged view of a part of part A in FIG. 1, and is a schematic diagram showing the surface of a structure. 3 is a sectional view taken along line BB in FIG. 2. FIG. FIG. 2 is a schematic diagram showing a color space of the L ^* a ^* b ^* color system. FIG. 1 is a block diagram of an inspection system according to a first embodiment. FIG. 3 is a schematic diagram of an infrared image of the surface of the structure before deformation. FIG. 3 is a schematic diagram of an infrared image of the surface of the structure after deformation. It is an infrared image obtained by an imaging device, and is a schematic diagram showing temperature distribution. 8 is a schematic diagram showing a displacement amount distribution obtained by image analysis based on a digital image correlation method for the infrared image shown in FIG. 7. FIG. It is a flow chart showing the inspection method of a 1st embodiment. It is a schematic diagram showing the inspection system of a 2nd embodiment. FIG. 7 is a schematic diagram of a structure according to a third embodiment. 12 is a sectional view taken along line FF in FIG. 11. FIG. 7 is a schematic diagram of a structure according to a fourth embodiment. 14 is a sectional view taken along line GG in FIG. 13. FIG. FIG. 7 is a schematic diagram of a structure according to a fifth embodiment. 16 is a sectional view taken along line HH in FIG. 15. FIG. It is a schematic diagram showing the inspection system of a 6th embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, the form (this embodiment) for implementing this invention is demonstrated. However, the present invention is not limited to the following content or the content shown in the drawings, and can be implemented with arbitrary modifications within a range that does not significantly impair the effects of the present invention. The present invention can be implemented by combining different embodiments. In the following description, the same members in different embodiments will be denoted by the same reference numerals, and overlapping explanations will be omitted.

FIG. 1 is a schematic diagram showing an inspection system 100 according to the first embodiment. The inspection system 100 inspects the structure 1 using infrared measurement. Specifically, in an infrared image obtained by infrared measurement, temperature changes occur due to thermoelastic effects accompanying deformation. Therefore, the inspection system 100 inspects the amount and direction of displacement (or only one of them) on the surface of the structure 1 caused by the deformation by applying the digital image correlation method to the infrared image where the temperature change has occurred. It is something to do. However, the inspection contents are not limited to this example.

The structure 1 inspected by the inspection system 100 is a power generation facility in the illustrated example, and specifically, a wind power generation facility. However, the structure 1 is not limited to power generation equipment, and may be a railway vehicle or a construction machine. That is, the structure 1 is, for example, at least one of a power generation facility, a railroad vehicle, or a construction machine, but the structure 1 is not limited to these.

For example, a structure 1 constituted by wind power generation equipment includes a blade 20, a tower 21, a rotating shaft 22, and a nacelle 23. The blade 20 is attached to a rotating shaft 22, and the rotating shaft 22 is connected to a power generator (not shown) in a nacelle 23. The rotation of the blades 20 drives the power generation device and generates electricity. The nacelle 23 is supported by the tower 21, and an imaging device 3 (described later) is installed on the top surface of the nacelle 23. The imaging device 3 will be described after the structure 1 is described. Note that the installation location of the imaging device 3 is not limited to the upper surface of the nacelle 23, and can be installed at any height and location, such as, for example, on the ground or on the tower 21. Further, for example, the imaging device 3 may be mounted on an unmanned aircraft (not shown), and the imaging device 3 may take an image while the unmanned aircraft is flying in synchronization with the rotation of the blade 20.

FIG. 2 is an enlarged view of a part of part A in FIG. 1, and is a schematic diagram showing the surface of the structure 1. As shown in FIG. In FIG. 2, the structure 1 is illustrated as a cross-sectional perspective view by cutting the surfaces on the front side and the back side of the paper along curved lines in order to show that the structure 1 extends beyond the illustrated area. The same applies to FIGS. 11, 13, and 15, which will be described later. Although details will be described later, the imaging device 3 images a portion of the structure 1 where stress is likely to concentrate (portion A shown in FIG. 2).

The structure 1 includes a first member 10 and a second member 11 disposed on the surface 10a of the first member 10. The surface 10a of the first member 10 has a color depending on the type of the structure 1, and is, for example, white in the case of the structure 1 exemplifying a wind power generation facility.

Although the details will be described later, the inspection performed in the first embodiment will be explained. The first member 10 and the second member 11 have different thermophysical property values, such as thermoelastic coefficients. Therefore, when the structure 1 is deformed, there is a temperature change due to the thermoelastic effect due to the deformation of the first member 10 constituting the structure 1, and a temperature change due to the thermoelastic effect due to the deformation of the second member 11 constituting the structure 1. The temperature changes are different. Therefore, in order to measure the difference in temperature change, an infrared image of the surface 10a of the structure 1 is obtained using, for example, infrared thermography. Then, based on the digital image correlation method for infrared images showing differences in temperature changes, the amount and direction of displacement of any point on the surface 10a of the structure 1 due to deformation can be measured.

The first member 10 is, for example, a base material that supports the second member 11, and is made of, for example, a polymeric resin material. Examples of polymeric resin materials include polyurethane resins, acrylic resins, fluorine resins, olefin resins, polyester resins, polyamide resins, epoxy resins, phenolic resins, vinyl chloride resins, polycarbonate resins, In addition to epoxy resins, examples include copolymers and mixtures of these resins.

The arrangement of the second member 11 on the first member 10 will be explained with reference to FIG. 3.

FIG. 3 is a sectional view taken along the line BB in FIG. The second member 11 is placed on the surface 10a of the first member 10 so that the surface 10a is partially exposed. In the illustrated example, the second members 11 are arranged in a scattered manner, specifically, in a mosaic pattern. By disposing the second member 11 in a scattered manner, the second member 11 can be disposed at any position regardless of the surface shape (for example, a flat surface or a curved surface) of the first member 10.

The amount of arrangement of the second member 11 on the first member 10 is, for example, the entire surface 10a of the first member 10 (the area imaged by the imaging device 3 (part A), which is the target for stress distribution evaluation). The second member 11 can be disposed in a scattered manner so that, for example, 30% or more, preferably 40% or more, and an upper limit of 70% or less, preferably 60% or less of the surface) is exposed. The second member 11 is preferably arranged evenly on all surfaces 10a of the first member 10.

The thickness of the second member 11 is, for example, 5 mm or less, preferably 3 mm or less, and more preferably 1 mm or less. By making the second member 11 within this thickness range, it is possible to suppress the second member 11 from looking three-dimensional when the structure 1 is visually recognized, and the second member 11 is less noticeable from the first member 10. can.

Returning to FIG. 2, the second member 11 has the same color as the first member 10 or is colorless and transparent. However, in FIG. 2 (including subsequent drawings), the second member 11 is illustrated in a color that is significantly different from the color of the first member 10 in order to make it easier to understand the arrangement of the second member 11. Similar colors include, for example, both the first member 10 and the second member 11 having the same color, or the first member 10 being white and the second member 11 being a whitish cream color. Since the second member 11 has the same color as the first member 10, the second member 11 can be made less noticeable. Similar colors will be explained with reference to FIG. 4.

FIG. 4 is a schematic diagram showing the color space of the L ^* a ^* b ^* color system. In the first embodiment, whether the color of the first member 10 and the color of the second member 11 are similar can be determined based on, for example, the L ^* a ^* b ^* color system. The L ^* a ^* b ^* color system was standardized by the International Commission on Illumination in 1976 and established in JIS Z8781-4:2013. In the L ^* a ^* b ^* color system, lightness is expressed as L ^* , and chromaticity indicating hue and saturation is expressed as a ^* b ^* . The larger the value of L ^* , the brighter it becomes, and the smaller the value of L ^* , the darker it becomes. a ^* and b ^* indicate the direction of color, a ^* indicates the red direction, -a ^* indicates the green direction, b ^* indicates the yellow direction, and -b ^* indicates the blue direction. In each of a ^* and b ^* , the larger the value, the clearer the color, and the closer to the center, the duller the color becomes.

In FIG. 4, point C and point D indicate the colors of the first member 10 and the second member 11, respectively. ΔL ^* is the difference between the lightness L ^* of the first member 10 and the lightness L ^* of the second member 11. Δa ^* and Δb ^* are the differences between the chromaticities a ^* and b ^* of the first member 10 and the chromaticities a ^* and b ^* of the second member 11, respectively. The color difference ΔE ^* ab between the first member 10 and the second member 11 can be calculated using the following formula (1).
ΔE ^* ab={(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 ...Formula (1)

In the first embodiment, it is determined whether the color of the first member 10 and the color of the second member 11 are similar colors based on the value of ΔE ^* ab. Specifically, it is preferable to determine that the color of the first member 10 and the color of the second member 11 are similar colors when the value of ΔE ^* ab is, for example, 0.4 or less. When the value of ΔE ^* ab is 0.4 or less, it is difficult for an average person to notice the second member 11 when viewing the structure 1. Among these, it is more preferable that the value of ΔE ^* ab is 0.2 or less. By setting the value of ΔE ^* ab to 0.2 or less, the color of the first member 10 and the color of the second member 11 can be made more difficult to visually distinguish, and the second member 11 can be made more difficult to notice.

The brightness and chromaticity of the first member 10 and the second member 11 can be determined using, for example, a color difference meter (for example, manufactured by Konica Minolta). Therefore, ΔE ^* ab can be calculated based on the brightness and chromaticity determined by, for example, a color difference meter. Further, the color difference can also be calculated by, for example, recording an image or moving image on a recording device using a high-resolution camera, and performing post-processing on the image processing device.

Note that the determination of whether or not the colors are similar does not need to be based on the L ^* a ^* b ^* color system; for example, the Munsell color system, the XYZ color system, the L ^* c ^* h color system, or the Hunter color system. A standardized color system such as the Lab color system may be used as a standard, or an original color system may be used.

Returning to FIG. 2, the second member 11 may be colorless and transparent. By making it colorless and transparent, the color of the first member 10 can be transmitted through the second member 11, making the second member 11 less noticeable. As for the degree of transparency, it is preferable that the second member 11 be as close to transparent as possible, and specifically, the transmittance of visible light is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more.

The second member 11 has a thermophysical property value different from that of the first member 10, which is a thermophysical property value that associates deformation with a temperature change caused by the deformation. Since the first member 10 and the second member 11 have different thermophysical property values, when the first member 10 and the second member 11 fixed to the first member 10 are deformed in the same way, the thermoelastic The degree of temperature change due to the effect can be different. This makes it possible to measure differences in temperature distribution due to differences in thermoelasticity in infrared images. By measuring the difference in temperature distribution, even if the material properties of the first member 10 cannot be accurately grasped, it is possible to simultaneously measure the amount of displacement and the direction of displacement based on the digital image correlation method.
Note that the thermoelastic effect means that the solid temperature decreases when the solid is adiabatically expanded, and the solid temperature increases when the solid is adiabatically compressed. Adiabatic expansion and compression occur due to deformation of the structure 1.

As described above, the thermophysical property value is a value that associates deformation with a temperature change caused by the deformation. Specifically, the thermophysical property value is, for example, a constant that determines the amount of change in temperature due to deformation when stress is generated, and is a constant that associates stress with the amount of temperature change. The thermophysical property value is, for example, at least one of a coefficient of thermal expansion, a coefficient of thermoelasticity, or a specific heat at constant pressure. By using these thermophysical property values, the distribution of stress fluctuations in the structure 1 can be evaluated based on known physical property values.

The thermophysical property value is determined based on the constituent materials of the first member 10 and the second member 11. An example of the constituent materials and thermophysical property values is shown in Table 1 below. Table 1 shows, as an example, the stress fluctuation Δσ when the thermal expansion coefficient is used as the thermophysical property value. In Table 1, SUS represents stainless steel and GFRP represents glass fiber reinforced resin. However, the constituent materials of the first member 10 and the second member 11 are not limited to the constituent materials shown in Table 1.

As mentioned above, the deformation of the structure 1 causes adiabatic expansion or compression. The resulting thermoelastic effect causes a temperature change in the structure 1. The temperature change ΔT1 due to the thermoelastic effect is calculated by the following equation (2).
ΔT1=-K _m・T・Δσ...Formula (2)
K _m is the thermoelastic coefficient (N/mm ² ), T is the ambient temperature (K), and Δσ is the stress fluctuation value of the structure 1 (N/mm ² (=MPa)). Note that the thermoelastic coefficient K _m can be calculated by dividing the linear expansion coefficient α by the product of the density ρ and the constant pressure specific heat C _p .

For example, when the ambient temperature (for example, outside temperature) T is 300 K and the temperature change ΔT1 of the structure 1 is 0.1 mK, if the constituent material is iron, for example, the thermoelastic coefficient K _m is 3.45 × 10 ^-6 (1 /(N・mm ² ), the stress fluctuation Δσ can be calculated as 0.97 N/mm ² .If the same calculation is performed for other constituent materials, the numerical values shown in Table 1 will be calculated. By infrared measurement using No. 3, it is possible to measure the difference in temperature distribution caused by the difference in thermoelasticity between the first member 10 and the second member 11.

As described above, the thermophysical property values of the first member 10 and the thermophysical property values of the second member 11 are different values. The thermophysical property value of the first member 10 may be larger than the thermophysical property value of the second member 11, and the thermophysical property value of the second member 11 may be larger than the thermophysical property value of the first member 10. However, it is preferable that the difference between the thermophysical property values of the first member 10 and the thermophysical property values of the second member 11 be as large as possible. Specifically, for example, the thermophysical property value of the larger thermophysical property value can be made to be, for example, twice or more, preferably three times or more, more preferably five times or more, the thermophysical property value of the smaller thermophysical property value. To illustrate a case where the thermophysical property value of the first member 10 is larger than the thermophysical property value of the second member 11, the thermophysical property value of the first member 10 is, for example, twice or more of the thermophysical property value of the second member 11, It can be increased preferably by 3 times or more, more preferably by 5 times or more.

To explain this point based on Table 1 above, it is assumed that the constituent material of the first member 10 is a fluororesin and the constituent material of the second member 11 is a polyurethane resin, for example. For example, the thermoelastic coefficient of fluororesin is 46.9×10 ⁻⁶ (1/(N/mm ² )), and the thermoelastic coefficient of polyurethane resin is 5.17×10 ⁻⁶ (1/(N/mm 2 )). ² )). Therefore, in this case, the thermophysical property value of the first member 10 is about nine times that of the second member 11. In this case, if the stress variation Δσ is 1.0 N/mm ² , the temperature variation ΔT1 of the first member 10 made of fluororesin is 14 mK, and the temperature variation ΔT1 of the second member 11 made of polyurethane resin is 15 mK.

By increasing the difference between the thermophysical property values of the first member 10 and the thermophysical property values of the second member 11 (for example, within the above range), the difference between the first member 10 and the second member due to deformation of the structure 1 can be reduced. 11 can be increased. Thereby, when the surface of the structure 1 is imaged by the imaging device 3, the difference between the high temperature portion and the low temperature portion can be clearly distinguished.

According to the structure 1 including the first member 10 and the second member 11, the second member 11 can be arranged on the first member 10 without significantly impairing the design provided by the first member 10. Thereby, infrared measurement of the structure 1 can be performed while maintaining the design of the structure 1.

Returning to FIG. 1, the inspection system 100 includes an imaging device 3 and an arithmetic processing device 50. The imaging device 3 measures the structure 1 using infrared light. The imaging device 3 is configured with, for example, an infrared thermograph that can measure temperature changes in an unsteady state. Thermoelastic heat generation caused by deformation of the structure 1 can be measured by infrared measurement. Further, by infrared measurement, for example, an infrared image (image showing temperature distribution) can be obtained in which relatively high temperature areas are displayed in dark colors and relatively low temperature areas are displayed in light colors.

The imaging device 3 is a single monocular camera that captures two-dimensional images, and is installed on the top surface of the nacelle 23 in the illustrated example. The imaging device 3 performs infrared measurement on a portion where stress concentration is likely to occur, specifically, the surface end portion of the blade 20 in the portion A in FIG. 1 . Other areas where stress concentration is likely to occur include, for example, joints that may exist in the structure 1, curved surfaces where the shape or dimensions suddenly change, notches, etc., and are not limited to the illustrated imaging location. do not have. For example, the imaging device 3 may image bolts or welded parts that fix the tower to a ground foundation (not shown).

The imaging device 3 acquires an infrared image of the blade 20, thereby performing infrared measurement. The acquired infrared image is transmitted to the arithmetic processing device 50. The arithmetic processing device 50 will be explained with reference to FIG.

FIG. 5 is a block diagram of the inspection system 100 of the first embodiment. The arithmetic processing device 50 includes an image acquisition section 51, a binarization processing section 52, an image analysis section 53, a display section 54, and a notification section 55.

The image acquisition unit 51 acquires an infrared image obtained by the imaging device 3. The infrared image acquired by the image acquisition section 51 is transmitted to the binarization processing section 52. Note that image acquisition (that is, imaging timing by the imaging device 3) is performed in synchronization with the rotation timing of the blade 20 so that the same portion of the blade 20 can be imaged.

The binarization processing unit 52 binarizes the infrared image obtained by the imaging device 3. The binarization processing unit 52 makes it possible to clarify the difference (for example, a difference in shading) between a high-temperature part and a low-temperature part in an infrared image, and improves the accuracy of image analysis by a digital image correlation method (described later). The threshold value used in the binarization process is arbitrary. For example, when the difference between the maximum temperature T _max and the minimum temperature T _min is ΔT2, the threshold value used in the binarization process is within the range of T _max -0.1×ΔT2≦T≦T _max . A threshold value can be set that converts a certain temperature portion to a temperature of T _max and erases other portions.

The image analysis unit 53 performs image analysis on the infrared image obtained by the imaging device 3 based on the digital image correlation method (DIC method). Using the acquired infrared images (digital images) of the structure 1 before and after deformation using the DIC method, it is possible to simultaneously determine the amount and direction of displacement of the surface of the structure 1 based on the brightness distribution in the infrared images. That is, the image analysis unit 53 can determine the amount and direction of displacement of the surface of the structure 1 due to the deformation of the structure 1. Determination of the displacement amount and displacement direction based on the DIC method will be explained with reference to FIGS. 6A and 6B.

FIG. 6A is a schematic diagram of an infrared image of the surface of the structure 1 before deformation. Moreover, FIG. 6B is a schematic diagram of an infrared image of the surface of the structure 1 after deformation. In FIGS. 6A and 6B, a pattern P called a speckle pattern is applied. In the first embodiment, the brightness distribution within a small image region (subset) R centered on an arbitrary point Q on the image before deformation (FIG. 6A) is determined. Then, in the image after deformation (FIG. 6B), a region S having a brightness distribution that has the best correlation with the brightness distribution of the region R before deformation is searched. By setting the center point U of the region S to the position of the point Q displaced by the deformation of the structure 1, the amount and direction of displacement of the point Q can be determined at the same time.

FIG. 7 is an infrared image obtained by the imaging device 3 and is a schematic diagram showing the temperature distribution. The dark areas are high temperature areas, and the thin areas are low temperature areas. Note that the shading shown in FIG. 7 does not necessarily match the placement location of the second member 11 shown in FIG. 2 and the like. Stress concentration is likely to occur due to shape discontinuities, cutouts, etc. Therefore, the imaging device 3 images the end of the blade 20, as shown in FIG. Note that the temperature change ΔT due to deformation of the structure 1 increases in a portion where stress concentration is likely to occur.

FIG. 8 is a schematic diagram showing a displacement amount distribution obtained by image analysis based on the DIC method on the infrared image shown in FIG. By image analysis of the infrared image shown in FIG. 7 by the image analysis unit 53, a visualized displacement amount distribution map (FIG. 8) including a displacement amount contour map 24 and a displacement vector diagram (not shown) is obtained. The obtained displacement amount distribution map is transmitted to the display section 54 and the notification section 55 (both will be described later). Note that the displacement amount distribution diagram may be recorded in a recording unit (not shown). Further, the displacement amount distribution map may be transmitted to another device via an external transmitter and a communication cable (which may be wireless), which are not shown.

Returning to FIG. 5, the display unit 54 displays the results of image analysis by the image analysis unit 53 on the display device 60. Specifically, in the first embodiment, the display unit 54 displays the displacement amount distribution diagram shown in FIG. 8 on the display device 60. The display device 60 is, for example, a monitor. By providing the display section 54, the user can check the displacement amount distribution map.

The notification unit 55 notifies the user of a warning when the result of image analysis by the image analysis unit 53 deviates from a predetermined standard. The standard here is, for example, a physical quantity related to deformation (e.g., displacement amount, etc.), and specifically, for example, a tolerance indicating that the deformation of the structure 1 does not have a large effect on the service life of the structure 1. It is the amount of displacement. The allowable displacement amount can be determined by, for example, experiments, trial runs, simulations, and the like. The allowable displacement amount may be a value input by a worker via an input device (for example, a keyboard) not shown.

For example, when the displacement amount determined based on the displacement amount distribution part is included in the displacement amount range that hardly affects the service life, the notification section 55 does not notify the alarm. However, if the amount of displacement determined based on the displacement distribution map deviates from the range of displacement that hardly affects the service life, that is, if the deformation of the structure 1 affects the service life of the structure 1, The notification unit 55 notifies an alarm. This allows the user to understand unacceptable displacement, and prompts the user to perform temporary inspection, for example.

The alarm is issued by driving the notification device 61 (for example, by flashing a red lamp, etc.). Further, by using the notification device 61 as the display device 60, a warning may be displayed on the display device 60. Further, the alarm may also be issued, for example, for a portion outside the displacement range (that is, a portion to be repaired).

Note that although none of the arithmetic processing units 50 are illustrated, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), and an I/F (interface). It is composed of the following. The arithmetic processing device 50 is realized by the CPU executing a predetermined control program stored in the ROM. Further, the arithmetic processing device 50 and the imaging device 3 are electrically connected by a wired cable or wirelessly. A power cable is connected to the arithmetic processing device 50 and the imaging device 3 as appropriate.

FIG. 9 is a flowchart showing the inspection method of the first embodiment. The inspection method shown in FIG. 9 can be executed mainly by the arithmetic processing device 50 shown in FIG. Therefore, in the following description, FIG. 9 will be described with reference to FIG. 5 as well.

The inspection method of the first embodiment includes an arrangement step S1, a measurement step S2, an image acquisition step S3, an image analysis step S5, a display step S6, and a notification step S8.

The arrangement step S1 is a step of arranging the second member 11 on the surface 10a of the first member 10 (see FIG. 2) so that the surface of the first member 10 is partially exposed. The first member 10 and the second member 11 are the same as the first member 10 and the second member 11 described in the description of the structure 1.

The arrangement of the second member 11 on the first member 10 can be arbitrarily determined depending on the form of the second member 11, for example. For example, when the second member 11 is a coating film, it can be arranged by applying a solution containing a solvent and a constituent material of the second member 11 to the first member 10 and drying it. Coating and drying can be performed with any coating and drying equipment. Further, the second member 11 can be formed into any shape such as a covering material, a thin sheet, a seal, etc., and fixed to the first member 10 so as not to fall off. Pasting can be performed by any pasting device.

The measurement step S2 is a step in which the structure 1 obtained by placing the second member 11 on the first member 10 is measured by infrared rays using the imaging device 3. Further, the image acquisition step S3 is a step in which the image acquisition unit 51 acquires an infrared image captured by the imaging device 3. Furthermore, the binarization processing step S4 is a step of performing binarization processing on the infrared image acquired by the image acquisition unit 51. The binarization processing step S4 is executed by the binarization processing section 52. As the threshold value used in the binarization process, for example, the threshold value explained in the description of the binarization processing unit 52 above can be used.

The image analysis step S5 is a step of performing image analysis on the infrared image obtained by the imaging device 3 based on the DIC method. The image analysis step S5 is executed by the image analysis section 53. Through the image analysis step S5, the amount and direction of displacement of the structure surface due to the deformation of the structure 1 can be determined at the same time. Further, the display step S6 is a step of displaying the results of image analysis by the image analysis section 53 on the display device 60. The display step S6 is executed by the display section 54.

The notification step S7 is a step of notifying the user of a warning when the result of the image analysis by the image analysis unit 53 deviates from a predetermined standard. The standard here has the same meaning as the content explained in the description of the notification section 55 above. The notification step S7 is executed by the notification unit 55.

According to the above inspection method and inspection system 100, the structure 1 can be inspected while maintaining the design of the structure 1. That is, since the color of the first member 10 and the color of the second member 11 are similar or the second member 11 is colorless and transparent, the second member 11 installed on the first member 10 is difficult to stand out when visually recognized. . Therefore, the structure 1 can be inspected while the design of the structure 1 is maintained (that is, without significant damage).

Further, for example, since the design of the structure 1 is maintained during inspection, the structure 1 can be inspected without stopping the operation of the structure 1. Therefore, economic losses due to the suspension of operation of the structure 1 can be suppressed. Furthermore, for example, when inspecting the structure 1 while the operation is stopped, the structure 1 may be subjected to new processing (for example, removal of speckled patterns and black paint as described in paragraph 0031 of Patent Document 1 above). There is no need to apply Therefore, after the inspection, there is no need to carry out any process to recover from the deterioration in design quality caused by the inspection, and it is possible to save the labor of the workers involved in the inspection.

Furthermore, since the analysis is performed based on infrared images, the structure 1 can be imaged and inspected day or night. Therefore, there is no need for lighting to illuminate the structure 1, and inspection can be easily performed. In addition to inspecting newly installed structures 1, it is also possible to easily inspect existing structures 1 that do not include the second member 11. That is, in the existing structure 1, simply by newly installing the second member 11 on the surface of the first member 10, inspection by the inspection system 100 can be easily performed.

Furthermore, by inspecting the structure 1, it is possible to record and analyze the occurrence tendency and frequency of displacement and distortion. In particular, the inspection by the inspection system 100 can be performed, for example, while the structure 1 continues to operate, as described above. Therefore, a large amount of inspection data can be acquired, and the accuracy of analyzing the tendency and frequency of occurrence of displacement and distortion can be improved. As a result, the maintenance plan can be optimized. Furthermore, by feeding back the analysis results to the person in charge of designing the structure 1, it is possible to strengthen the structure 1 when designing the next model, thereby increasing the reliability of the structure 1.

FIG. 10 is a schematic diagram showing an inspection system 200 of the second embodiment. The structure 1 shown in FIG. 10 can be inspected, for example, by the inspection system 100 described above. In FIG. 1, a power generation facility is illustrated as the structure 1, but in FIG. 10, a railway vehicle is illustrated as the structure 1.

A railway vehicle constituting the structure 1 runs on a rail 41 via a bogie 42 and includes an entrance/exit section 43 and a window section 44 . Similarly to the power generation equipment described above, in railway vehicles, stress tends to concentrate, for example, at corner portions, portions where the shape changes, and the like. Therefore, in the illustrated example, the imaging device 3 images the vicinity of the window frame of the window portion 44 (portion E in FIG. 10) where stress tends to concentrate, and the inspection system 200 performs the inspection.

The imaging device 3 is installed on the ground. Therefore, when the structure 1 constituted by a railway vehicle passes through the installation location of the imaging device 3, the imaging device 3 images the vicinity of the window frame of the window portion 44. Thereby, the amount and direction of displacement of the window portion 44 in the vicinity of the window frame can be measured simultaneously.

The inspection system 200 uses two imaging devices 3a and 3b to obtain a three-dimensional image. Therefore, in the inspection system 200, the infrared images obtained by the imaging devices 3a and 3b are three-dimensional images. The imaging devices 3a and 3b are each monocular cameras, but may also be stereo cameras. By obtaining a three-dimensional image, a visualized displacement distribution map of the three-dimensional surface including the depth direction as well as the in-plane direction can be obtained. Therefore, the amount of displacement not only in the in-plane direction but also in the depth direction can be measured.

FIG. 11 is a schematic diagram of a structure 1 according to the third embodiment. Further, FIG. 12 is a cross-sectional view taken along the line FF in FIG. 11. The structure 1 shown in FIGS. 11 and 12 can be inspected, for example, by the inspection system 100 described above.

In the third embodiment as well, the second members 11 are arranged in a scattered manner on the surface 10a of the first member 10, similarly to the first embodiment. However, in the third embodiment, unlike the first embodiment, the second member 11 is arranged in a spotted pattern on the surface 10a of the first member 10. Although the second member 11 includes spots of various sizes in the illustrated example, it may be composed of spots of the same size. Further, the second member 11 is not limited to a circular shape, and may be formed into a spotted pattern on the first member 10, such as an ellipse, a rectangle, or a hexagon.

The second member having a spotted pattern can be arranged by pasting the second member 11, which is constituted by a circular sticker in the illustrated example, on the surface 10a of the first member 10. Therefore, by arranging the second members 11 in a spotted pattern, the second members 11 can be easily arranged.

FIG. 13 is a schematic diagram of the structure 1 according to the fourth embodiment. Further, FIG. 14 is a sectional view taken along the line GG in FIG. 13. The structure 1 shown in FIGS. 13 and 14 can be inspected, for example, by the inspection system 100 described above.

In the fourth embodiment, the second members 11 are arranged in a grid pattern. By arranging the second members 11 in a grid pattern, the second members 11 can be arranged continuously even if the surface 10a of the first member 10 has a large size (surface area). Thereby, the second member 11 can be easily arranged.

Moreover, a plurality of unit surfaces 10b are formed on the surface 10a of the first member 10 by being surrounded by the grid-like second member 11, and the shapes of the plurality of unit surfaces 10b are all different. In this way, by arranging the grid-like second members 11 so that the shapes of the unit surfaces 10b are different, the second members 11 can be arranged irregularly. As a result, when image analysis is performed by the image analysis unit 53 (see FIG. 5), it is possible to easily determine where the point Q before deformation (see FIG. 6A) has moved due to the deformation. That is, since the second member 11 is arranged irregularly, the arrangement form of the second member 11 differs between the region S to which the point Q moves (see FIG. 6B) and the region R before movement (see FIG. 6A). are different. Therefore, the temperature distribution is different, and the amount and direction of displacement of the point Q can be easily determined in image analysis based on the DIC method.

Note that the arrangement form of the second members 11 arranged in a grid pattern is not limited to the illustrated example including straight lines and curved lines, and may be only straight lines or only curved lines. Moreover, the second member 11 may have a suitably distorted shape. The location and number of second members are not limited to the illustrated example. Further, as described above, although it is preferable that the grid-like second members 11 be arranged irregularly, they may be arranged regularly (that is, the shapes of the unit surfaces 10b are all the same).

FIG. 15 is a schematic diagram of the structure 1 according to the fifth embodiment. Further, FIG. 16 is a sectional view taken along line HH in FIG. 15. The structure 1 shown in FIGS. 15 and 16 can be inspected, for example, by the inspection system 100 described above.

The structure 1 of the fifth embodiment includes a protection member 12 having thermophysical property values different from those of the first member 10 and the second member 11 on the surface 10a of the first member 10 so as to cover the second member 11. The protective member 12 is made of, for example, a resin material with excellent environmental resistance. In addition, although the protective member 12 is arranged so as to cover the entire surface 10a of the first member 10 in the illustrated example, the protective member 12 only needs to cover at least the second member 11, and only a part of the surface 10a. The protective member 12 may be arranged at the. The protective member 12 may be colorless and transparent, colored and transparent, or opaque.

By providing the protective member 12, the second member 11 can be protected, and detachment of the second member 11 from the first member 10 and change in physical properties of the second member 11 can be suppressed. In addition, since the protective member 12 has thermophysical property values different from those of the first member 10 and the second member 11, when the structure 1 is deformed, the thermoelastic effect of the first member 10 and the second member 11 causes The temperature change can be measured from the outside (i.e., the surface side) of the protection member 12. Furthermore, since the second member 11 is covered by the protective member 12, the unevenness of the surface 10a caused by the second member 11 is alleviated. Thereby, the second member 11 can be made even less noticeable.

FIG. 17 is a schematic diagram showing an inspection system 300 according to the sixth embodiment. The structure 1 inspected by the inspection system 300 is a construction machine in the illustrated example, and more specifically a hydraulic excavator. The structure 1 shown in FIG. 17 can be inspected, for example, by the inspection system 100 described above.

In the structure 1 constituted by a hydraulic excavator, an upper revolving body 82 is mounted on a lower traveling body 81 . The upper revolving body 82 includes a boom 83, an arm 84, a bucket 85, a boom cylinder 86, an arm cylinder 87, and a bucket cylinder 88. The imaging device 3 is installed on the side of the boom 83 and is capable of capturing an image of the corner of the side of the boom 83. Thereby, the displacement at the corner of the side surface of the boom 38 and the direction of displacement can be measured simultaneously. However, the installation location and imaging part of the imaging device 3 are not limited to this, and for example, the imaging device 3 may be installed on the upper revolving structure 82 or the like to image the upper revolving structure 82.

1 Structure 10 First member 100 Inspection system 10a Surface 10b Unit surface 11 Second member 12 Protective member 20 Blade 200 Inspection system 21 Tower 22 Rotating shaft 23 Nacelle 3 Imaging device 300 Inspection system 3a Imaging device 3b Imaging device 41 Rail 42 Dolly 43 Entrance/exit section 44 Window section 50 Arithmetic processing unit 51 Image acquisition section 52 Binarization processing section 53 Image analysis section 54 Display section 55 Notification section 60 Display device 61 Notification device 81 Lower traveling body 82 Upper rotating body 83 Boom 84 Arm 85 Bucket 86 Boom cylinder 87 Arm cylinder 88 Bucket cylinder

Claims (14)

a first member, disposed on the surface so that the surface of the first member is partially exposed, has a similar color to the first member or is colorless and transparent, and is resistant to deformation and temperature changes caused by the deformation. a plurality of second members each having an associated thermophysical property value different from that of the first member, and each having the same color when the first member has a similar color; an imaging device that measures structures in infrared;
By performing image analysis based on a digital image correlation method using infrared images before and after the deformation of the structure obtained by the imaging device, the amount of displacement of an arbitrary point on the surface of the structure due to the deformation can be determined. An inspection system comprising: an arithmetic processing unit including an image analysis unit that determines the image analysis unit; In the L ^* a ^* b ^* color system, the difference between the lightness L ^* of the first member and the lightness L* of the second member is ΔL ^* , and the chromaticity a ^* , b ^* of the first member and the lightness L ^* of the second member are ΔL*. If the differences between the chromaticities a ^* and b ^* of the two members are Δa ^* and Δb ^* , then the following formula (1) is obtained.
ΔE ^* ab={(ΔL ^* ) ² +(Δa ^* ) ²⁺ (Δb ^* ) ² } ^1/2 ...Color difference between the first member and the second member calculated by equation (1) The inspection system according to claim 1, wherein the value of ΔE ^* ab is 0.4 or less. The inspection system according to claim 1 or 2, wherein the thermophysical property value is at least one of a coefficient of thermal expansion, a coefficient of thermoelasticity, or a specific heat at constant pressure. The inspection system according to claim 1 or 2, wherein the second member is arranged in a scattered manner. The inspection system according to claim 1 or 2, wherein the second member is arranged in a grid pattern. A plurality of unit surfaces are formed on the surface of the first member by being surrounded by the second member in a lattice shape,
The inspection system according to claim 5, wherein all of the plurality of unit surfaces have different shapes. The inspection system according to claim 1 or 2, wherein the second member has a thickness of 5 mm or less. The structure includes a protective member having thermophysical property values different from those of the first member and the second member on the surface of the first member so as to cover the second member. Inspection system. The inspection system according to claim 1 or 2, wherein the arithmetic processing unit includes a binarization processing unit that binarizes an infrared image obtained by the imaging device. The inspection system according to claim 1 or 2, wherein the infrared image obtained by the imaging device is a three-dimensional image. The inspection system according to claim 1 or 2, wherein the arithmetic processing device includes a display unit that displays the results of image analysis by the image analysis unit on a display device. The inspection system according to claim 1 or 2, wherein the arithmetic processing device includes a notification unit that notifies a user of a warning when the result of image analysis by the image analysis unit deviates from a predetermined standard. The inspection system according to claim 1 or 2, wherein the structure is at least one of a power generation facility, a railway vehicle, or a construction machine. The first member has a thermophysical property value that is similar in color to the first member or colorless and transparent so that the surface of the first member is partially exposed, and that associates deformation with a temperature change caused by the deformation. an arrangement step of arranging a plurality of second members on the surface, each having a thermophysical property value different from that of the second member and having the same color when the second member is similar in color to the first member;
a measuring step of measuring infrared rays with an imaging device the structure obtained by placing the second member on the first member;
By performing image analysis based on a digital image correlation method using infrared images before and after the deformation of the structure obtained by the imaging device, the amount of displacement of an arbitrary point on the surface of the structure due to the deformation can be determined. an image analysis step for determining the inspection method.

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