WO2017179535A1

WO2017179535A1 - Structure condition assessing device, condition assessing system, and condition assessing method

Info

Publication number: WO2017179535A1
Application number: PCT/JP2017/014667
Authority: WO
Inventors: 浩今井
Original assignee: 日本電気株式会社
Priority date: 2016-04-15
Filing date: 2017-04-10
Publication date: 2017-10-19

Abstract

The objective of the present invention is to make it possible to carry out accurate categorized detection of defects in a structure, such as cracking, detachment or internal voids, remotely and in a non-contact manner. The condition assessing device of the present invention comprises: a displacement calculating unit which calculates, from differences between images of a structure surface captured at a first imaging distance and a second imaging distance, a two-dimensional spatial distribution of displacements in the images, and which calculates, from an image of the structure surface prior to application of a load, captured at the first imaging distance, and differences between said image and time-series images of the structure surface resulting from the application of the load, a two-dimensional spatial distribution of displacements in the time-series images; a depth movement amount calculating unit which calculates the first imaging distance from the two-dimensional spatial distribution of the displacements between the images, and uses the first imaging distance to calculate an amount of movement of the structure surface, in the direction of a normal line thereto, resulting from the application of the load, from the two-dimensional spatial distribution of the displacements in the time-series images; a displacement separating unit which separates the two-dimensional spatial distribution of the displacements of the structure surface by calculating a correction amount on the basis of the amount of movement, and subtracting the correction amount from the two-dimensional spatial distribution of the displacements in the time-series images; and an abnormality assessing unit which identifies defects in the structure on the basis of a comparison between the two-dimensional spatial distribution of the displacements of the structure surface and the movement amount, and thresholds relating to the spatial distribution of the displacements and to the movement amount, provided in advance.

Description

Structure state determination apparatus, state determination system, and state determination method

The present invention relates to a technique for remotely determining the state of a defect or the like occurring in a structure.

In concrete structures such as tunnels and bridges, it is known that defects such as cracks, delamination and internal cavities occurring on the surface of the structure affect the soundness of the structure. Therefore, in order to accurately determine the soundness of the structure, it is necessary to accurately detect these defects.

Detecting defects such as cracks, delamination, and internal cavities in structures has been performed by visual inspection and hammering inspection by an inspector, and it is necessary for the inspector to approach the structure for inspection. For this reason, there are problems such as an increase in work cost by preparing an environment where work can be performed in the air and loss of economic opportunities by regulating traffic for setting the work environment. A remote inspection method is desired.

There is a method based on image measurement as a method for determining the state of a structure from a remote location. For example, a technique has been proposed in which an image obtained by imaging a structure with an imaging device is binarized with a predetermined threshold, and an image portion corresponding to a crack is detected from the binarized image (patent) Reference 1). Moreover, the technique which detects the crack which has arisen in the structure from the stress state of a structure is proposed (patent document 2, patent document 3). Also, a system (Patent Document 4) that uses both an infrared imaging device or a visible light imaging device and a laser imaging device to automatically analyze a captured image to determine a defect of a measurement object, and has excellent portability There has been proposed a method (Patent Document 5) for creating a defect map from an image captured by an image capturing means. Furthermore, Non-Patent Document 1 discloses a method for improving the detection accuracy of cracks by detecting the movement of a crack region from a moving image on the surface of a structure.

JP 2003-035528 A JP 2008-232998 A JP 2006-343160 A JP 2004-347585 A Japanese Patent Laid-Open No. 2002-236100 JP 2012-132786 A JP 2013-181773 A JP 2007-057386 A JP 2009-180562 A

However, in the above technique, for example, when imaging the lower surface of a structure such as a bridge, the structure is deflected by a load, so that the displacement of the surface to be imaged moves in the normal direction of the surface (out-of-plane Displacement) is added to the displacement in the in-plane direction of the surface having information on the defect of the structure (referred to as in-plane displacement). For this reason, there existed a subject that the precision at the time of detecting the defect of a structure fell.

Patent Document 6 proposes a method of correcting an out-of-plane displacement from a displacement of a captured image in a method of measuring distortion generated on the surface of a measurement object. In Patent Document 6, the out-of-plane displacement is read from the side images before and after the deformation of the structure. For this purpose, two video devices are provided, a first video device that images the surface of the structure and a second video device that images the side surface. That is, in this method, in order to photograph the side surface, another image device is required in addition to the image device that photographs the surface, and there is a problem in increasing the size and cost of the device.

Also, Patent Document 7 discloses a method of illuminating pattern light and calculating a displacement from corresponding line segments between zoom-in image data and zoom-out image data. However, in this method, pattern light illuminating means such as a projector is required to illuminate the pattern light, and the increase in size and cost of the apparatus are problems.

Further, when the apparatus is enlarged as in Patent Document 6 and Patent Document 7, for example, in the case of a bridge or the like, it is necessary to fix the imaging device or to secure an operator's scaffold in order to measure the side surface of the bridge. There is a problem that workability is deteriorated and measurement accuracy is lowered.

Also, Patent Document 8 and Patent Document 9 disclose a method for obtaining the distance of a target object by superimposing and capturing two images with different optical paths using a single camera. However, this method requires a means for performing processing for separating superimposed imaging in order to capture superimposed imaging on a single imaging device, and this processing is complicated and time consuming. It has become.

The present invention has been made in view of the above-described problems, and its purpose is to detect defects such as cracks, peeling, and internal cavities of a structure with high accuracy while controlling costs in a non-contact manner from a remote location. It is to make it possible.

The state determination apparatus of the present invention calculates a two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances, and before applying a load at the first imaging distance. A displacement calculation unit for calculating a two-dimensional spatial distribution of the displacement of the time-series image from a difference between the image of the surface of the structure and a time-series image of the surface of the structure by applying a load, and a two-dimensional spatial distribution of the displacement of the image The first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the time-series image, and the amount of movement in the normal direction of the surface of the structure due to the load application is calculated using the first imaging distance. A depth movement amount calculation unit calculates a correction amount based on the movement amount, and subtracts the correction amount from a two-dimensional spatial distribution of the displacement of the time-series image to obtain a two-dimensional spatial distribution of the displacement of the structure surface. A displacement separating portion to be separated from the surface of the structure; It has a two-dimensional spatial distribution and the amount of movement of the position, and the threshold value relating to the amount of movement and spatial distribution of pre-equipped was displaced, based on a comparison of, and a malfunction determination unit for specifying a defect of the structure.

The state determination system of the present invention calculates a two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances, and before applying a load at the first imaging distance. A displacement calculation unit for calculating a two-dimensional spatial distribution of the displacement of the time-series image from a difference between the image of the surface of the structure and a time-series image of the surface of the structure by applying a load, and a two-dimensional spatial distribution of the displacement of the image The first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the time-series image, and the amount of movement in the normal direction of the surface of the structure due to the load application is calculated using the first imaging distance. A depth movement amount calculation unit calculates a correction amount based on the movement amount, and subtracts the correction amount from a two-dimensional spatial distribution of the displacement of the time-series image to obtain a two-dimensional spatial distribution of the displacement of the structure surface. Displacement separation part to be separated and the structure table An abnormality determination unit that identifies a defect of the structure based on a comparison between a two-dimensional spatial distribution of displacement and the amount of movement, and a spatial distribution of displacement provided in advance and a threshold value related to the amount of movement. A state determination device; and an imaging device that captures the time-series image and the image and provides the image to the state determination device.

According to the state determination method of the present invention, a two-dimensional spatial distribution of the displacement of the image is calculated from the difference between the images of the structure surface at the first and second imaging distances, and before applying the load at the first imaging distance. A two-dimensional spatial distribution of the displacement of the time-series image is calculated from a difference between the image of the surface of the structure and a time-series image of the surface of the structure by applying a load, and the first two-dimensional spatial distribution of the displacement of the image The moving distance in the normal direction of the surface of the structure due to the load application is calculated from the two-dimensional spatial distribution of the displacement of the time series image using the first imaging distance, and the moving distance is calculated. A correction amount is calculated based on the two-dimensional spatial distribution, and the two-dimensional spatial distribution of the displacement of the structure surface is separated by subtracting the correction amount from the two-dimensional spatial distribution of the displacement of the time-series image. The two-dimensional spatial distribution and the movement amount are provided in advance. A threshold for the movement amount and spatial distribution of the displacement, based on a comparison of, identifying a defect in the structure.

The state determination apparatus of the present invention calculates a two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances, and before applying a load at the first imaging distance. A displacement calculation unit for calculating a two-dimensional spatial distribution of the displacement of the time-series image from a difference between the image of the surface of the structure and a time-series image of the surface of the structure by applying a load, and a two-dimensional spatial distribution of the displacement of the image The first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the time-series image, and the amount of movement in the normal direction of the surface of the structure due to the load application is calculated using the first imaging distance. A depth movement amount calculation unit; and an abnormality determination unit that identifies a defect of the structure based on a comparison between the movement amount and a threshold value relating to the movement amount provided in advance.

According to the state determination method of the present invention, a two-dimensional spatial distribution of the displacement of the image is calculated from the difference between the images of the structure surface at the first and second imaging distances, and before applying the load at the first imaging distance. A two-dimensional spatial distribution of the displacement of the time-series image is calculated from a difference between the image of the surface of the structure and a time-series image of the surface of the structure by applying a load, and the first two-dimensional spatial distribution of the displacement of the image The moving distance in the normal direction of the surface of the structure due to the load application is calculated from the two-dimensional spatial distribution of the displacement of the time series image using the first imaging distance, and the moving distance is calculated. And a defect of the structure is specified based on a comparison with a threshold value relating to the movement amount provided in advance.

According to the present invention, it is possible to accurately detect defects such as cracks, peeling, and internal cavities of a structure from a remote location in a non-contact manner while suppressing costs.

It is a block diagram which shows the structure of the state determination apparatus of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the state determination system of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the state determination apparatus of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the imaging device of the state determination system of the 2nd Embodiment of this invention. It is a figure for demonstrating the relationship between the state (when healthy) of a structure, and the displacement of a surface. It is a figure for demonstrating the relationship between the state (in the case of a crack) of a structure, and the displacement of a surface. It is a figure for demonstrating the relationship between the state (in the case of peeling) of a structure, and the displacement of a surface. It is a figure for demonstrating the relationship between the state of a structure (in the case of an internal cavity), and the displacement of a surface. It is a figure for demonstrating the out-of-plane displacement when the lower surface of a structure is imaged when a bending generate | occur | produces in a structure by a load. It is a figure for demonstrating the relationship between an out-of-plane displacement vector, an in-plane displacement vector, and a measurement vector. It is a figure which shows the graph of the magnitude | size of an out-of-plane displacement vector. It is a figure which shows the magnitude | size graph of an out-of-plane displacement vector. It is a figure which shows the graph of the magnitude | size of an out-of-plane displacement vector, and the magnitude | size of a measurement vector. It is a figure which shows the result of having calculated the displacement of the surface of the X direction of the structure (in the case of a crack) before and behind a load in the displacement calculation part. It is a figure which shows the result of having calculated the displacement of the surface of the Y direction of the structure (in the case of a crack) before and behind a load by the displacement calculation part. It is a figure which shows the result of having calculated the in-plane displacement of the surface of the surface of the X direction of the structure (in the case of a crack) before and behind a load in the displacement separation part. It is a figure which shows the result of having calculated the in-plane displacement of the surface of the Y direction surface of the structure (in the case of a crack) before and behind a load in the displacement separation part. It is a figure which shows the structure of the imaging device of the state determination system of the 2nd Embodiment of this invention. It is a figure which shows the structure of the imaging device of the state determination system of the 2nd Embodiment of this invention. It is a figure which shows another structure of the imaging device of the state determination system of the 2nd Embodiment of this invention. It is a figure which shows another structure of the imaging device of the state determination system of the 2nd Embodiment of this invention. It is a figure for demonstrating the calculation method of the correction amount in case a structure has an inclination. It is a figure which shows distribution of the stress field around a crack. It is a figure which shows distribution of the stress field around a crack. It is a figure which shows the example of the two-dimensional distribution (X direction) of the displacement around a crack (when a crack is shallow). It is a figure which shows the example of the two-dimensional distribution (Y direction) of the displacement around a crack (when a crack is shallow). It is a figure which shows the example of the two-dimensional distribution (X direction) of the displacement around a crack (when a crack is deep). It is a figure which shows the example of the two-dimensional distribution (Y direction) of the displacement around a crack (when a crack is deep). It is a figure explaining the pattern matching with the displacement distribution (pattern of the X direction of a displacement) by the abnormality determination part. It is a figure explaining the pattern matching with the displacement distribution (the pattern of the Y direction of a displacement) by the abnormality determination part. It is a figure explaining pattern matching with the displacement distribution (pattern of the differential vector field of a displacement) by an abnormality determination part. It is a perspective view which shows the two-dimensional distribution of the stress of the surface seen from the imaging direction in case an internal cavity exists. It is a top view which shows the two-dimensional distribution of the stress of the surface seen from the imaging direction in case an internal cavity exists. It is a figure which shows the contour line (X component) of the displacement of the surface seen from the imaging direction in case an internal cavity exists. It is a figure which shows the contour line (Y component) of the displacement of the surface seen from the imaging direction in case an internal cavity exists. It is a figure which shows the stress field of the surface seen from the imaging direction in case an internal cavity exists. It is a figure explaining the response at the time of giving an impulse stimulus to a structure in case an internal cavity exists (position ABC which obtains a response is shown). It is a figure explaining the response at the time of giving an impulse stimulus to a structure in case an internal cavity exists (the response in position ABC is shown). It is a figure which shows the contour line (X component) of the displacement of the surface seen from the imaging direction in case peeling exists. It is a figure which shows the contour line (Y component) of the displacement of the surface seen from the imaging direction in case peeling exists. It is a figure which shows the stress field of the surface seen from the imaging direction in case peeling exists. It is a figure for demonstrating the time response of the displacement at the time of giving impulse stimulation to the structure in case peeling exists. It is a figure which shows a mode that a structure (when healthy) bends with a load. It is a figure which shows a mode that a structure (in the case of deterioration) bends with a load. It is a figure which shows the example which divided | segmented the imaging range of the lower surface of a structure into several area | region. It is a figure which shows the example which calculates | requires the deflection amount for every several area | region divided | segmented. It is a figure which shows the change of the movement amount (deflection amount) in the time from the start to the end of load application. It is a figure for demonstrating the characteristic way of bending when there exists a cavity in the inside of a structure. It is a flowchart which shows the state determination method in the state determination apparatus of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the preferred embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following.
(First embodiment)
FIG. 1 is a block diagram illustrating a configuration of a state determination device according to an embodiment of the present invention. The state determination device 100 according to the present embodiment calculates a two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances, and loads at the first imaging distance. A displacement calculation unit 101 that calculates a two-dimensional spatial distribution of the displacement of the time-series image from the difference between the image of the structure surface before application and the time-series image of the structure surface by applying a load. Further, the first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the image, and the amount of movement in the normal direction of the structure surface due to the load application is calculated from the two-dimensional spatial distribution of the displacement of the time-series image. A depth movement amount calculation unit 102 that calculates using the first imaging distance is provided. Further, a displacement separation unit that calculates a correction amount based on the movement amount, subtracts the correction amount from a two-dimensional spatial distribution of the displacement of the time-series image, and separates the two-dimensional spatial distribution of the displacement of the structure surface. 103. Furthermore, an abnormality that identifies a defect in the structure based on a comparison between a two-dimensional spatial distribution of displacement of the structure surface and the amount of movement, and a spatial distribution of displacement provided in advance and a threshold value related to the amount of movement. The determination unit 104 is included.

According to the state determination device 100, the imaging distance on the surface of the structure and the amount of movement in the normal direction of the surface of the structure due to load application can be obtained. Furthermore, an out-of-plane displacement due to the movement of the surface of the structure in the normal direction can be obtained using the movement amount. By subtracting this out-of-plane displacement from the displacement caused by the load on the image of the structure surface, the in-plane displacement of the structure surface can be separated. According to the state determination apparatus 100, the above processing can be easily performed with good workability, and therefore, detection that distinguishes defects such as cracks, peeling, and internal cavities of the structure can be performed remotely and accurately with no contact. Is possible.

As described above, according to the present embodiment, it is possible to accurately detect defects such as cracks, delamination, and internal cavities of a structure from a remote location in a non-contact manner while suppressing costs.
(Second Embodiment)
FIG. 2 is a block diagram illustrating a configuration of a state determination system according to the second embodiment of this invention. The state determination system 10 includes a state determination device 1 and an imaging device 11. The imaging device 11 captures the surface of the structure 20 before and after applying a load to the structure 20 as a time-series image on the XY plane, and inputs the captured image information to the state determination device 1. The imaging device 11 also captures an image of the surface of the structure 20 at an imaging distance before applying a load and an image of the surface of the structure 20 at an imaging distance different from the imaging distance, and these images. Information is input to the state determination device 1. The state determination device 1 acquires the image information as described above from the imaging device 11.

In FIG. 2, the structure 20 as the object to be measured has a beam-like structure supported at two points, but is not limited to this. In addition, various defects 21 may exist in the structure 20.

FIG. 3 is a block diagram showing a configuration of the state determination device 1. The state determination device 1 includes a displacement calculation unit 2, a depth movement amount calculation unit 3, a displacement separation unit 4, a differential displacement calculation unit 5, an abnormality determination unit 6, and an abnormality map creation unit 9. The abnormality determination unit 6 includes a three-dimensional spatial distribution information analysis unit 7 and a time change information analysis unit 8.

FIG. 4 is a block diagram illustrating a configuration of the imaging device 11. The imaging device 11 includes an optical path length control unit 12, a lens 13, an imaging element 14, and a processing circuit 15. The lens 13, the image sensor 14, and the processing circuit 15 constitute an imaging camera. The processing circuit 15 inputs an image of the surface of the structure 20 formed on the imaging surface of the imaging device 13 by the lens 13 to the state determination device 1. The optical path length control unit 12 can change the optical path length (imaging distance) from the lens 13 to the surface of the structure 20 to be imaged.

The displacement calculation unit 2 of the state determination device 1 calculates the displacement for each (X, Y) coordinate on the XY plane of the time-series image. That is, using the frame image before the load application captured by the imaging device 11 as a reference, the displacement in the frame image at the first time after the load application is calculated from the difference between these frame images. Next, the displacement of the image before the load application is calculated for each time series image, such as the displacement of the frame image at the next time after the load application, and further the displacement of the frame image at the next time.

The displacement calculation unit 2 also changes the imaging distance of the surface of the structure 20 before the load is applied by the optical path length control unit 12 for each (X, Y) coordinate on the XY plane. Calculate the displacement.

The displacement calculation unit 2 can calculate the displacement using image correlation calculation. Further, the displacement calculating unit 2 can also represent the calculated displacement as a displacement distribution diagram having a two-dimensional spatial distribution on the XY plane.

The depth movement amount calculation unit 3 calculates the imaging distance before applying the load from the displacement of the image of the surface of the structure 20 having a different imaging distance. Further, the depth movement amount calculation unit 3 calculates, using the calculated imaging distance, a movement amount by which the surface of the structure 20 moves in the normal direction due to the deflection of the structure 20 from the displacement of the time-series image. To do. The depth movement amount calculation unit 3 inputs the movement amount to the displacement separation unit 4, the differential displacement calculation unit 5, and the abnormality determination unit 6.

The displacement separation unit 4 calculates a displacement based on the movement amount included in the displacement of the time-series image (referred to as out-of-plane displacement) using the calculated movement amount. Furthermore, the displacement separation unit 4 separates the displacement (referred to as in-plane displacement) generated on the surface of the structure 20 by subtracting the out-of-plane displacement from the displacement of the time-series image. The displacement separation unit 4 inputs the separated in-plane displacement to the differential displacement calculation unit 5 and the abnormality determination unit 6.

The differential displacement calculation unit 5 performs spatial differentiation on the displacement or displacement distribution diagram of the time-series image and the movement amount, and the differential displacement or the calculated differential displacement is converted into a two-dimensional differential space distribution on the XY plane. The distribution map and differential movement amount are calculated. The differential displacement calculation unit 5 inputs the calculation result to the abnormality determination unit 6.

The abnormality determination unit 6 determines the state of the structure 20 based on the input calculation result. That is, the abnormality determination unit 6 determines the location and type of the abnormality (defect 21) of the structure 20 from the analysis results of the three-dimensional spatial distribution information analysis unit 7 and the time change information analysis unit 8. Furthermore, the abnormality determination unit 6 inputs the determined abnormality location and type of the structure 20 to the abnormality map creation unit 9. The abnormality map creation unit 9 maps the spatial distribution of the abnormal state of the structure 20 to the XY plane, records it as an abnormality map, and outputs the result.

The state determination device 1 can be an information device such as a PC (Personal Computer) or a server. By using a CPU (Central Processing Unit), which is a computing resource of an information device, and a memory or HDD (Hard Disk Drive), which is a storage resource, each part of the state determination device 1 is operated by the CPU. Can be realized.

5A to 5D are diagrams for explaining the relationship between various abnormal states of the structure 20 and in-plane displacement of the surface. FIG. 5A is a side view of the beam-like structure 20 supported at two points. As illustrated in FIG. 5A, the imaging device 11 is arranged to image the lower surface of the structure 20 in the imaging direction (Z direction). At this time, if the structure 20 is healthy, as shown in FIG. 5A, a compressive stress is applied to the upper surface of the structure 20 and a tensile stress is applied to the lower surface with respect to the vertical load from the upper surface of the structure 20. . The structure 20 may not be a beam-like structure that is supported at two points as long as the same stress is applied.

Here, when the structure 20 is an elastic body, the stress is proportional to the strain. The Young's modulus, which is a proportional constant, depends on the material of the structure. Since the strain proportional to the stress is a displacement per unit length, the strain can be calculated by spatially differentiating the result calculated by the displacement separation unit 4 by the differential displacement calculation unit 5. That is, the stress field can be obtained from the result of the differential displacement calculation unit 5.

As shown in FIG. 5B, when a crack exists, the cracked portion is greatly displaced by a load. On the other hand, since there is no transmission of stress around the cracked portion, the tensile stress on the lower surface of the structure 20 is smaller than the healthy state shown in FIG. 5A.

In addition, as shown in FIG. 5C, when peeling is present, the appearance seen from the lower surface of the structure 20 is observed as in the case of cracking. However, in the case of peeling, there is no stress transmission between the peeling part and the upper part thereof. Therefore, the displacement due to the load only translates a certain amount in a certain direction in the peeled portion, and no distortion which is a spatial differential value is generated. Therefore, it is possible to distinguish between cracking and peeling by using strain information obtained by spatially differentiating displacement due to load.

Also, as shown in FIG. 5D, when an internal cavity exists, the stress on the lower surface of the structure 20 is reduced because the transmission of stress is hindered in the internal cavity. Therefore, since the distortion calculated from the image is also reduced, it is possible to find an internal cavity that cannot be directly seen from the outside of the structure 20.

The displacement of the structure surface to be measured in FIGS. 5A to 5D is an in-plane displacement (X direction and Y direction) in the XY plane. Therefore, the displacement separation unit 4 uses the apparent displacement (out-of-plane displacement) based on the amount of movement of the surface of the structure 20 in the normal direction due to the load calculated by the depth movement amount calculation unit 3 as a correction amount. The in-plane displacement is separated by calculating and subtracting this out-of-plane displacement. Hereinafter, a method for calculating the out-of-plane displacement will be described.

In addition, although the normal line is referred to when the surface is a curved surface, when the surface has a plurality of small curved surfaces and forms a large curved surface as a whole, the normal line for the large curved surface is used here. . Moreover, although it is called a perpendicular for the case where the surface is a plane, in the following description, it will be expressed as a normal line for simplicity.

FIG. 6 is a diagram for explaining the out-of-plane displacement when the lower surface of the structure is imaged (see FIG. 2) when the structure 20 is bent due to the load. In FIG. 6, the amount of movement of the surface of the structure 20 in the normal direction (Z direction) is caused by the deflection of the structure and is expressed as a deflection amount δ. Note that the amount of movement of the surface in the Z direction is not limited to the amount of deflection, and may include, for example, the amount of movement when the entire structure 20 sinks due to a load.

As shown in FIG. 6, when a deflection (deflection amount δ) occurs in the structure 20 due to the load, the imaging surface of the imaging device 14 of the imaging device 11 has a two-dimensional space of displacement of the structure surface in the X direction. Apart from Δx _i corresponding to the in-plane displacement Δx which is the distribution, an out-of-plane displacement δx _i occurs due to the deflection amount δ. Similarly, Δy _i corresponding to the in-plane displacement Δy and an out-of-plane displacement δy _i due to the deflection amount δ are generated in the Y direction. The out-of-plane displacements δx _i , δy _i, and in-plane displacements Δx _i , Δy _i are: L is the imaging distance, f is the lens focal length, and (x, y) is the coordinate from the imaging center of the structure surface. They are represented by Formula 1, Formula 2, Formula 3, and Formula 4, respectively.

For example, when the deflection δ before and after the load of the structure 20 is 4 mm, the imaging distance L is 5 m, and the lens focal length f is 50 mm, the distance x from the imaging center on the surface of the structure 20 is 200 mm. The external displacement δx _i is 1.6 μm from Equation 1. On the other hand, when an in-plane displacement Δx of 160 μm is present on the surface of the structure 20, the in-plane displacement Δx _i of the imaging surface is 1.6 μm from Equation 3. In this way, when the displacement distribution diagram calculated by the displacement calculation unit 2 or the displacement distribution diagram representing the two-dimensional spatial distribution on the XY plane is superimposed with an out-of-plane displacement equivalent to the in-plane displacement There is.

Here, when Formula 1 and Formula 2 are combined as out-of-plane displacement vectors δi (δx _i , δy _i ), and Formulas 3 and 4 are combined as in-plane displacement vectors Δi (Δx _i , Δy _i ), Formulas 5 and 6 are respectively obtained. It becomes.

FIG. 7 is a diagram illustrating the relationship between the out-of-plane displacement vector δi (δx _i , δy _i ) and the in-plane displacement vector Δi (Δx _i , Δy _i ) expressed by Equations 5 and 6. 7, out-of-plane displacement vector δi (δx _{_i,} δy _i) the radial vector group (thin solid line arrow in FIG. 7), and its size, R (x, y) Formula from Equation 1 and Equation 2 It becomes like 7. According to Equation 7, if the deflection amount δ is constant, the magnitude thereof is a value proportional to the distance from the imaging center, and if the proportionality constant is set to k as shown in Equation 8, Equation 7 becomes Equation 9 It is expressed as follows.

Here, the displacement distribution calculated by the displacement calculation unit 2 includes an out-of-plane displacement vector δi (δx _i , δy _i ) (thin solid line arrow in FIG. 7) and an in-plane displacement vector Δi (Δx _i , Δy _i ). It is a measurement vector V (Vx, Vy) (dotted line arrow in FIG. 7) which is a combined vector with (a thick solid line arrow in FIG. 7). When the magnitude of the measurement vector V (Vx, Vy) is Rmes (x, y), it is expressed as Expression 10 and Expression 11.

8A and 8B are graphs showing examples of values of the magnitude R (x, y) of the out-of-plane displacement vector δi (δx _i , δy _i ) given by the

equations

7, 8, and 9. 8A and 8B are graphs showing the magnitude R (x, y) of the out-of-plane displacement vector when the deflection amount δ is 1 mm and 4 mm, respectively, and the imaging distance L before deflection of both graphs is 5000 mm. The focal length f is 50 mm. As can be seen by comparing the graphs of FIGS. 8A and 8B, both graphs are similar in shape, and the larger the deflection amount δ, the larger the enlargement ratio. This enlargement ratio corresponds to the proportionality constant k given by Equation 8.

FIG. 9 is a graph in which the magnitude Rmes (x, y) of the measurement vector V (Vx, Vy) is superimposed on the graph of FIG. 8B. In FIG. 9, Rmes (x, y) is indicated by a thin solid line. Rmes (x, y) is a magnitude R (x of the out-of-plane displacement vector when the magnitude R (x, y) of the out-of-plane displacement vector is larger than the in-plane displacement vector Δi (Δx _i , Δy _i ). , Y), and the enlargement rate of R (x, y) can be estimated from Rmes (x, y). The enlargement ratio of R (x, y) is estimated by obtaining a proportionality constant k that minimizes the evaluation function E (k) shown in Expression 12.

The calculation of the enlargement factor k using Equation 12 is performed using the least square method. The evaluation function E (k) may use a sum of absolute values, another sum of powers, or the like other than the square sum of the difference between Rmes (x, y) and R (x, y).

The displacement separation unit 4 performs an operation of converting the estimated enlargement factor k into a deflection amount δ using Expression 8, and estimates an out-of-plane displacement vector. The displacement separation unit 4 further extracts the in-plane displacement vector by subtracting the out-of-plane displacement vector as a correction amount from the measurement vector obtained by the displacement calculation unit 2.

Hereinafter, taking the case where the structure 20 has a crack along the Y direction as shown in FIG. 5B as an example, the out-of-plane displacement is calculated, and the calculated out-of-plane displacement is subtracted from the measured displacement to calculate the in-plane displacement. An example of extraction will be described. For the calculation of the displacement by the displacement calculating unit 2, a time series image obtained by imaging the lower surface of the structure 20 shown in FIG. 2 from the imaging direction shown in the drawing before and after applying the load is used.

Here, the imaging distance is 5 m, the structure 20 is concrete having a length of 20 m, a thickness of 0.5 m, and a width of 10 m (Young's modulus is 40 GPa). . The region where the displacement of the image is measured is in the range of ± 200 mm in both the X direction and the Y direction, with the crack portion on the surface of the structure 20 as the image center.

As an example, the focal length of the lens 13 of the imaging device 11 is 50 mm, the pixel pitch of the imaging element 14 is 5 μm, and a pixel resolution of 250 μm is obtained at an imaging distance of 5 m. The imaging device 14 of the imaging device 11 is a monochrome device having 2000 pixels horizontally and 2000 pixels vertically so that a range of 0.5 m × 0.5 m can be imaged at an imaging distance of 5 m. The frame rate of the image sensor 14 is 60 Hz. Further, in the image correlation in the displacement calculation unit 2, sub-pixel displacement estimation by quadratic curve interpolation is used so that displacement can be estimated up to 1/100 pixels so that a displacement resolution of 2.5 μm can be obtained. it can.

When the above-described imaging device 11 is used, the image displacement measurement region (in the range of −200 mm to 200 mm in both the X direction and the Y direction) is horizontal 1600 pixels and vertical 1600 pixels. The calculation of Expression 1 to Expression 12 is performed for this pixel region.

10A and 10B are diagrams respectively showing the X direction displacement distribution at Y = 0 mm and the Y direction displacement distribution at X = 0 mm of the measurement vector V (Vx, Vy) obtained by the displacement calculation unit 2. 10A and 10B do not consider the out-of-plane displacement included in the measurement vector V (Vx, Vy), and the displacement obtained from Equation 6 is the displacement in the coordinates of the surface to be measured of the structure 20. It is a graph.

In FIG. 10A showing the displacement in the X direction, a displacement of ± 170 μm occurs in the imaging range of ± 200 mm. In FIG. 10B showing the displacement in the Y direction, a displacement of ± 160 μm is linearly generated in the imaging range of ± 200 mm. The displacement in the X direction is a displacement in which an out-of-plane displacement is superimposed on an in-plane displacement. On the other hand, the displacement in the Y direction is a displacement of only out-of-plane displacement.

Using the measurement vector V (Vx, Vy) obtained by the displacement calculation unit 2, the proportionality constant k that minimizes the evaluation function E (k) of Equation 12 is obtained as 0.000008 by the least square method. By substituting this value into Equation 8, the deflection amount δ is obtained as 4 mm and becomes the output of the depth movement amount calculation unit 3.

Substituting this deflection amount δ into Equation 5, the out-of-plane displacement vector δi (δx _i , δy _i ) is obtained by the displacement separation unit 4. The displacement separation unit 4 further subtracts the out-of-plane displacement vector δi (δx _i , δy _i ) from the measurement vector V (Vx, Vy) obtained by the displacement calculation unit 2 to thereby obtain an in-plane displacement vector Δi ( Δx _i , Δy _i ) are obtained, and in-plane displacements in the X direction and the Y direction are calculated from Equation 6.

11A and 11B show the output of the displacement separation unit 4. FIG. 11A is a graph showing the displacement in the X direction, and a discontinuous rapid 20 μm displacement occurs in the cracked portion. On the other hand, FIG. 11B is a graph showing the displacement in the Y direction, and the displacement is zero. As shown in FIGS. 11A and 11B, the out-of-plane displacement can be separated to extract the in-plane displacement of the structure surface.

Here, a method in which the depth movement amount calculation unit 3 calculates the imaging distance L from the switching of the optical path length in the optical path length control unit 12 of the imaging device 11 will be described.

12A and 12B are diagrams illustrating the configuration of the optical path length control unit 12a of the imaging device 11a of the state determination system 10 and how the optical path length is switched by the optical path length control unit 12a. The optical path length control unit 12a of the imaging device 11a (the processing circuit 15 is omitted) includes a parallel plate glass 12a1 and a movable mechanism 12a2. The parallel flat glass 12a1 has a refractive index n and a thickness t of the lens 13 in the optical axis direction. The movable mechanism 12a2 switches whether the parallel plate glass 12a1 is inserted into the optical path or not when the imaging device 11a images the surface of the structure 20.

FIG. 12A shows a case where the parallel flat glass 12a1 is not inserted. In this case, the imaging distance is L. On the other hand, FIG. 12B is a case where the parallel flat glass 12a1 is inserted. At this time, the apparent optical path length variation δ ′ due to the insertion of the parallel flat glass 12 a 1 is as shown in Equation 13.

This optical path length change amount δ ′ can be handled in the same manner as the deflection amount δ causing the change in the imaging distance of Equations 1 to 8. Therefore, using δ ′ instead of δ, a proportionality constant k that minimizes the evaluation function E (k) of Expression 12 is obtained from the displacement of the image with and without the parallel flat glass 12a1 being inserted. The imaging distance L is calculated using Equation 8 from the obtained proportionality constant k, the optical path length change amount δ ′ obtained from Equation 13, and the known focal length f.

For example, when the refractive index n of the parallel flat glass 12a1 is 1.5 and the thickness t is 12 mm, δ ′ is 4 mm according to Equation 13. The proportionality constant k that minimizes the evaluation function E (k) of Equation 12 using the measurement vector V (Vx, Vy) obtained by the displacement calculation unit 2 from the displacement of the image with and without the insertion of the parallel flat glass 12a1. Is obtained by the method of least squares, and 0.000008 is obtained. Solving Equation 8 for L and substituting δ ′ = 4 mm, proportionality constant k = 0.000008, and focal length f = 50 mm, the imaging distance L = 5 m is obtained.

The optical path length control unit 12a is not limited to the parallel plate glass 12a1, and the refractive index may be changed by an element having an electrooptic effect such as liquid crystal. Moreover, the imaging device 11 is not limited to the imaging device 11a of FIG. 12A and FIG. 12B.

FIG. 13 is a diagram for explaining a state in which the optical path length is switched by the optical path length control unit 12b having a configuration different from that in FIGS. 12A and 12B. The optical path length control unit 12b of the imaging device 11b (the processing circuit 15 is omitted) includes a mirror 12b1 and a movable mechanism 12b2 that moves the mirror 12b1 in the optical axis direction (Z-axis direction). Further, in the image pickup apparatus 11b, an image can be formed on the image pickup element 14 by moving the lens 13 and the image pickup element 14 in conjunction with the movable mechanism 12b2. As described above, according to the imaging device 11b, the optical path length can be changed by moving the mirror 12b1 by the movable mechanism 12b2, and thus the imaging distance L can be obtained.

FIG. 14 is a diagram for explaining a state in which the optical path length is switched by the optical path length control unit 12c having still another configuration. The optical path length control unit 12c of the imaging device 11c (the processing circuit 15 is omitted) includes a half mirror 12c1, a mirror 12c2, and a lens 13. The imaging device 11c can capture the image 2 at the imaging distance L + δ ′ by the optical path length control unit 12c together with the image 1 at the imaging distance L. If the optical path does not pass through the center (optical axis) and an image is formed on a plurality of optical paths, the lens 13 has imaging characteristics as long as the image 1 and the image 2 are divided and focused on the optical axis. Is not greatly reduced, and even a general-purpose lens can be geometrically corrected by image processing.

In this case, the displacement calculation unit 2 of the state determination device 1 cuts out portions of the image 1 and the image 2 captured by the image sensor 14 and calculates the displacement of the image 2 with respect to the image 1. The depth movement amount calculation unit 3 can obtain the imaging distance L from the displacement of the image as in FIGS. 12A-B and FIG.

Further, in the case of FIG. 14, the depth movement amount calculation unit 3 can obtain the imaging distance for each time-series image. That is, the depth movement amount calculation unit 3 can obtain the deflection amount δ (movement amount) for each time series image from the imaging distance obtained for each time series image. The displacement separation unit 4 can obtain an out-of-plane displacement vector using the amount of movement and the imaging distance L before applying the load. The displacement separating unit 4 can also subtract the in-plane displacement vector by subtracting the out-of-plane displacement vector from the measurement vector of the time-series image acquired from the displacement calculating unit 2.

As a method for obtaining the imaging distance L, Non-Patent Document 2 discloses a two-lens camera configuration in which two sets of two mirrors are attached to a normal camera having a lens and an imaging element. On the other hand, in the method of FIG. 14, it is only necessary to add the half mirror 12c1 and the mirror 12c2, and the number of additional parts can be suppressed. In Non-Patent Document 2, the lens has a configuration in which the optical path does not pass through the center and images a plurality of optical paths.

As described above, according to the state determination system 10 of the present embodiment, even if the imaging distance L is not measured in advance, the imaging is performed by switching the optical path length by the optical path length control unit 12 provided in the imaging device 11. The distance L can be obtained. When determining the state of a structure, it is not actually easy to measure the imaging distance simply and accurately due to poor workability. According to the state determination system 10 of the present embodiment that can measure the imaging distance together with the imaging of the time series images of the surface of the structure, the imaging distance can be easily and accurately obtained.

FIG. 15 is a diagram illustrating a case where the structure 20 has an inclination in the calculation method of out-of-plane displacement. As shown in FIG. 15, when the normal of the surface of the structure 20 is rotated by θ around the Y axis, the coordinate with the optical axis of the imaging device 11 as the z axis and the normal of the structure surface is z. 'The relationship with the coordinate as the axis is expressed by Equation 14, Equation 15, and Equation 16.

XY coordinates of the image plane rotated by θ about the Y axis are mapped by Expression 17 and Expression 18.

Therefore, the out-of-plane displacement δx _{i in} the X direction and the Y direction due to the displacement from the coordinate P1 (x1, y1, z1) to the coordinate P2 (x2, y2, z2) due to the deflection of the structure 20 by the application of a load. The out-of-plane displacement δy _i is expressed by Equation 19 and Equation 20, respectively (Y component is not shown in FIG. 15).

Therefore, when there is an inclination θ, a function R (θ) obtained by substituting Equation 19 and Equation 20 into Equation 7 is obtained. Here, when the tilt angle θ is unknown, θ is changed from 0 ° to 90 ° in increments of 0.5 °, for example, and the evaluation function E of Equation 12 is used using the function R (θ) at each angle θ. Find k (θ) that minimizes (k). The angle that minimizes the evaluation function E (k) among all the obtained k (θ) is defined as the inclination angle. The deflection amount δ is obtained from the relationship between k at this inclination angle and Equation 8. The out-of-plane displacement vector δi (δx _i , δy _i ) can be estimated from the relationship between the obtained inclination angle and the amount of deflection δ and the

expressions

14, 15, 16, 17, 17, 18, and 20.

This result is input to the displacement separation unit 4 as an output of the depth movement amount calculation unit 3. The displacement separation unit 4 obtains the in-plane displacement vector Δi (Δx _i , Δy _i ) by subtracting the out-of-plane displacement vector δi (δx _i , δy _i ) from the measurement vector V (Vx, Vy). Here, with respect to the in-plane displacement vector Δi (Δx _i , Δy _i ), the projection onto the surface after application of the load is calculated using Expression 14, Expression 15, Expression 16, Expression 17, and Expression 18 to obtain the structure. The in-plane displacement of the object can be obtained.

In FIG. 15, the case where the normal of the surface of the structure 20 is rotated by θ with respect to the optical axis at the center of the imaging direction of the imaging device 11 with the Y axis as an axis is handled. When the axis is the axis, correction can be performed in the same way.

The in-plane displacement of the structure surface, which is the output of the displacement separation unit 4, is replaced with the distortion of the structure surface by the differential displacement calculation unit 5. Multiplying the strain on the surface of the structure by the Young's modulus results in stress, and from this, the stress field on the surface of the structure is obtained. The displacement information obtained by the displacement separation unit 4, the strain information obtained by the differential displacement calculation unit 5, and the movement amount obtained by the depth movement amount calculation unit 3 are input to the abnormality determination unit 6.

The abnormality determination unit 6 determines the type of defect based on the displacement information obtained by the displacement separation unit 4, the strain information obtained by the differential displacement calculation unit 5, and the movement amount obtained by the depth movement amount calculation unit 3. And identify the location. For this reason, the abnormality determination unit 6 preliminarily instructs the three-dimensional spatial distribution information analysis unit 7 and the time change information analysis unit 8 to determine a threshold value for determining a defect, a characteristic displacement corresponding to the type of defect, It has a distortion pattern. The three-dimensional spatial distribution information analysis unit 7 and the time change information analysis unit 8 are shown in FIG. 5A to FIG. 5D by comparing displacement information, strain information, movement amount and the threshold value, and pattern matching with the pattern. Determine the healthy state or defects such as cracks, delamination and internal cavities.

In the following description, as an order of description of the operation of the abnormality determination unit 6, first, a determination operation for the displacement information obtained by the displacement separation unit 4 and the distortion information obtained by the differential displacement calculation unit 5 (X direction and Next, the determination operation (Z direction) for the movement amount obtained by the depth movement amount calculation unit 3 will be described in order.

First, the determination operation (X direction and Y direction) for the displacement information obtained by the displacement separation unit 4 and the strain information obtained by the differential displacement calculation unit 5 will be described.

FIG. 11A shows an example of in-plane displacement of the surface in the X direction of the structure due to load application when a crack along the Y direction exists. It can be seen that a 20 μm discontinuous in-plane displacement occurs in the cracked portion. Such a sudden displacement does not occur in a healthy state with no defects. Therefore, it is possible to detect a crack by confirming a displacement exceeding this by providing a threshold value for the magnitude of discontinuous displacement in advance.

FIG. 16A and FIG. 16B are diagrams showing the distribution of the stress field around the crack portion calculated by the differential displacement calculation unit 5 when there is a crack along the Y direction. As shown in FIG. 16A, since the stress direction is bent by the crack, even when tensile stress is applied to both ends of the structure in the X direction in FIG. Thus, a component in the Y direction is generated. Therefore, cracks can also be detected by detecting the presence or absence of the component in the Y direction. In addition, since the distribution of the stress field around the crack is known as a stress intensity factor in an elastic body showing a linear response, the information can also be used.

FIGS. 17A to 17D show examples of the two-dimensional displacement distribution of the displacement around the crack. 17A and 17B are displacement contour lines in the horizontal direction (X direction) and the direction perpendicular to the paper surface (Y direction) in FIG. 5B, respectively. In FIG. 17A, the displacement contour line in the X direction has an abrupt displacement at the position of the crack. This corresponds to an abrupt displacement at the crack portion shown in FIG. 11A. On the other hand, on the outer side (X direction) of the crack, the density of the contour lines is sparser than in the region where there is no crack. The region in which the displacement contour lines are sparse corresponds to a gentle displacement portion outside the rapid displacement at the crack portion shown in FIG. 11A. The displacement at this portion is gentler than the displacement when there is no crack.

Also, as shown in FIG. 17B, in the Y direction, a component in the Y direction of displacement is generated around the cracked portion. This is because the stress component in the Y direction is generated around the edge of the cracked portion as shown in FIG. 16B. As a result of the displacement in the Y direction due to the stress in the Y direction, displacement contour lines in the Y direction are generated as shown in FIG. 17B.

FIGS. 17C and 17D show the cases where the cracks are deeper than those in FIGS. 17A and 17B, respectively. In this case, the density of the displacement contour lines becomes sparser around the crack in each of the X direction and the Y direction. It is also possible to know the depth of cracks from this density information.

The above-described crack determination is performed by the three-dimensional spatial distribution information analysis unit 7 of the abnormality determination unit 6 of the state determination device 1 in FIG.

When there is a crack, as shown in FIG. 11A, in the cracked portion, the displacement rapidly increases corresponding to the increase of the crack opening. Therefore, it is possible to estimate that there is a crack at a location where a displacement exceeding the threshold is detected by previously setting a threshold of displacement per unit length in the X direction or the Y direction.

Also, the strain in the X direction increases rapidly at the cracked portion. From this, it is possible to estimate that there is a crack at a location where a strain exceeding the threshold is detected by providing a threshold in advance in the value of strain in the X direction.

Also, as shown in FIGS. 16A and 16B, when there is a crack, distortion in the Y direction occurs. Therefore, by providing a threshold value in advance in the strain value in the Y direction, it can be estimated that there is a crack at a location where a strain exceeding the threshold value is detected.

Each of the above threshold values can be set by a simulation using the same dimensions and materials as the structure or an experiment using a reduced model. Furthermore, an actual structure can be set from data accumulated by measuring over a long period of time.

The above determination can also be made by a pattern matching process as described below, without using the above numerical comparison.

18A to 18C are diagrams for explaining the pattern distribution processing of the displacement distribution by the three-dimensional spatial distribution information analysis unit 7. FIG. According to the displacement separating unit 4 and the differential displacement calculating unit 5, as shown in FIGS. 17A to 17D, the displacement can be represented as a displacement distribution diagram on the XY plane. As shown in FIG. 18A, the three-dimensional spatial distribution information analysis unit 7 rotates and enlarges / reduces the X-direction pattern of the displacement around the crack stored in advance, and the displacement distribution diagram obtained by the displacement separation unit 4 By the pattern matching, it is possible to determine the direction and depth of the crack. Here, the X-direction pattern of the displacement around the crack stored in advance can be created in advance by simulation or the like for each depth and width of the crack.

Further, as shown in FIG. 18B, the three-dimensional spatial distribution information analysis unit 7 rotates and enlarges / reduces the pre-stored displacement around the crack in the Y direction, and the displacement distribution obtained by the displacement separation unit 4 The direction and depth of the crack are determined by pattern matching with the figure. Here, the Y-direction pattern of the displacement around the crack stored in advance can be created in advance by simulation or the like for each depth and width of the crack.

Further, as shown in FIG. 18C, the three-dimensional spatial distribution information analysis unit 7 rotates and enlarges / reduces the previously stored differential vector field pattern around the crack, and the differential displacement calculation unit 5 obtains it. The direction and depth of the crack are determined by pattern matching with a differential vector field (corresponding to a stress field). Here, the differential vector field pattern of the displacement around the crack stored in advance can be created in advance by simulation or the like for each depth and width of the crack.

The correlation calculation is used for the pattern matching. Various other statistical calculation methods may be used for pattern matching.

As mentioned above, although the case where the structure 20 has a crack has been demonstrated, the case where it has an internal cavity and the case where it peels is demonstrated below.

19A and 19B show a two-dimensional distribution of stress on the surface viewed from the imaging direction when an internal cavity as shown in FIG. 5D exists. FIG. 19A is a perspective view, and FIG. 19B is a plan view. As shown in FIG. 19B, stress acts in the X direction of the figure due to the load, but the stress field bends in the hollow portion, and therefore there is a component in the Y direction of the figure in the stress.

20A to 20C are diagrams showing the contour lines of the displacement of the surface and the stress field as seen from the imaging direction in the presence of the internal cavity. FIG. 20A shows the contour lines of the displacement X component, and FIG. 20A shows the contour lines of the displacement Y component. FIG. 20B shows the stress field and FIG. 20C shows the stress field.

In the hollow portion, since the amount of strain is reduced as described in the explanation of FIG. 5D, the density of contour lines of the X component of the displacement shown in FIG. 20A is reduced. Further, the contour line of the Y component of the displacement shown in FIG. 20B is a closed curve. Furthermore, the stress field that is the differential of the displacement shown in FIG. 20C is bent at the hollow portion. Since the influence of the surface stress field becomes more prominent as the cavity portion is closer to the surface, the depth from the surface of the cavity portion can also be estimated from the bending method of the stress field.

Here, the displacement pattern in the X direction of the displacement around the cavity, the displacement pattern in the Y direction of the displacement around the cavity, and the differential vector field (corresponding to the stress field) stored in advance in the three-dimensional spatial distribution information analysis unit 7 As in the case of determining a crack, applying FIG. 20A to FIG. 18A, FIG. 20B to FIG. 18B, and FIG. 20C to FIG. 18C makes it possible to determine the state of the position and depth of the internal cavity. For the pattern matching, correlation calculation is used, but other statistical calculation methods may be used.

Also, in the case of having an internal cavity, it can be estimated from the characteristics of the displacement in the Y direction and the distortion in the Y direction that thresholds are set in advance for these displacements and distortions and the internal cavity exists when the threshold is exceeded.

21A and 21B are diagrams for explaining the response when a load is applied to a structure having an internal cavity for a short time (referred to as impulse stimulation). Impulse stimulation can be applied, for example, to a position where a load is applied. FIG. 21B shows the time response of displacement at each point on the surface of A, B, and C shown in FIG. 21A in response to this impulse stimulus. At point A where there is no internal cavity, stress transmission is fast and the amplitude of displacement is large. On the other hand, at point C, since stress is not transmitted in the internal cavity, stress is transmitted from the periphery of the cavity, so that stress transmission is slow and the displacement amplitude is small. Further, the stress transmission time and amplitude at the point B which is between the points A and C are intermediate values between the points A and C. Therefore, when the frequency distribution of the displacement distribution in the plane of the structure viewed from the imaging direction is analyzed by the time change information analysis unit 8 in the abnormality determination unit 6, the region of the internal cavity is determined from the amplitude and phase near the resonance frequency. Can be identified. Further, the internal cavity may be determined from the shift of the resonance frequency.

Even when the load is applied for a long time, a change in displacement corresponding to FIG. 21B is confirmed at the initial stage of applying the load. However, in this case, the convergence value of the displacement is not zero but a value that balances the load. Therefore, even when a load is applied for a long time, the internal cavity region can be specified by the time change information analysis unit 8.

The time response processing of the above displacement is performed by frequency analysis using fast Fourier transform in the time change information analysis unit 8. For frequency analysis, various frequency analysis methods such as wavelet transform may be used.

22A to 22C are diagrams showing the contour lines of the displacement of the surface and the stress field as seen from the imaging direction when there is peeling. 22A shows the contour line of the X component of the displacement, FIG. 22B shows the contour line of the Y component of the displacement, and FIG. 22C shows the stress field.

As shown in FIG. 5C, when there is peeling, an appearance similar to a crack is observed when viewed from the lower surface of the beam-like structure. However, since there is no stress transmission between the peeled portion and its upper part, the displacement before and after the load only translates by a certain amount in the fixed direction at the peeled portion, and no distortion which is a spatial differential value is generated.

FIG. 22A shows the contour line of the X component of the displacement. Since the peeled portion is not distorted and moves in a certain direction, there is no contour line. The abnormality determination unit 6 can determine that there is peeling using this feature. In addition, since the point A in the figure is difficult to transmit stress due to tearing due to peeling, the contour lines are sparse compared to the point B which is a healthy part. The abnormality determination unit 6 may determine the peeled portion and the healthy portion using this property.

FIG. 22B shows the contour line of the Y component of the displacement. A displacement in the Y direction occurs outside the outer periphery of the peeled portion. The abnormality determination unit 6 can determine that there is peeling using this feature. Moreover, the stress field which is the differential of the displacement shown in FIG. 22C is 0 or a value in the vicinity thereof at the peeled portion. The abnormality determination unit 6 can determine that there is peeling using this feature.

Here, the displacement pattern in the X direction of the displacement around the separation, the displacement pattern in the Y direction of the displacement around the cavity, and the differential vector field (corresponding to the stress field) stored in advance in the three-dimensional spatial distribution information analysis unit 7 As in the case of determining the depth of the crack, applying FIG. 22A to FIG. 18A, FIG. 22B to FIG. 18B, and FIG. 22C to FIG. For the pattern matching, correlation calculation is used, but other statistical calculation methods may be used.

FIG. 23 is a diagram showing a time response when a structure having delamination receives an impulse stimulus. In the time response, the peeled portion and the healthy portion have waveforms in which the displacement directions are opposite, that is, the phases are 180 ° different. Moreover, since the peeled portion is light, the amplitude is large. By performing frequency analysis on the displacement distribution in the plane of the structure viewed from the imaging direction by the time change information analysis unit 8, the separation portion can be identified from the amplitude and phase. In addition, since the peeled portion floats from the entire structure, the peeled portion may include a frequency component different from that of the entire structure. Therefore, the peeled portion may be determined from a shift in resonance frequency.

In the above processing, the frequency analysis in the time change information analysis unit 8 uses fast Fourier transform. For frequency analysis, various frequency analysis methods such as wavelet transform may be used.

Next, the movement amount obtained by the depth movement amount calculation unit 3 and the determination operation (Z direction) for the differential value of the movement amount will be described.

FIG. 24A and FIG. 24B are diagrams showing a state in which a structure is bent by a load. FIG. 24A shows a healthy case, and FIG. 24B shows a deteriorated case. When the structure deteriorates due to aging or the like and loses elasticity, the amount of deflection becomes larger in the deteriorated state of FIG. 24B than in the healthy state of FIG. 24A. For this reason, assuming that the factor of the movement amount calculated by the depth movement amount calculation unit 3 is the deflection amount, a threshold value is provided for the deflection amount, and when the movement amount exceeds this threshold value, it can be determined that the deterioration has occurred. This threshold value can be converted from a deflection amount when a predetermined load is applied in advance, for example, by calculating strength when designing the structure.

The three-dimensional spatial distribution information analysis unit 7 of the abnormality determination unit 6 compares the amount of movement with a threshold value to determine deterioration. By the way, when a structure bends, there is a case of not only a smooth curve drawing as shown in FIGS. 24A and 24B but also a flexure including a complicated change instead of a smooth curve. FIG. 25A and FIG. 25B are examples of the above determination performed by the three-dimensional spatial distribution information analysis unit 7, and are diagrams for explaining processing in the case of performing a deflection including a complicated change in the X direction.

As shown in FIG. 25A, the imaging range is divided into, for example, nine areas from area A to area I. By calculating the proportionality constant k that minimizes the evaluation function E (k) shown in Expression 12 for each region, the amount of deflection (the amount of movement in the Z direction) in each region is calculated (FIG. 25B). . The amount of deflection in each region can be represented by the amount of deflection at the center of each region, for example, as shown in FIG. 25B. By comparing the deflection amount of each region with a deflection amount threshold value set in advance in each region, it is possible to determine which region is deteriorated. Note that the number and size of area divisions can be arbitrarily set.

FIG. 26 is a diagram illustrating a change in the movement amount (deflection amount) in the time from the start to the end of load application. In FIG. 26, the time change of the movement amount in the region B of FIG. 25A is shown. From the time change of the movement amount, for example, the maximum value of the movement amount can be set as the deflection amount. Deterioration can be determined by comparing the amount of deflection with a threshold value. The time change of the movement amount can be recorded for each area.

FIG. 27 is a diagram illustrating a characteristic way of bending when there is a cavity inside the structure. The method of bending when there is an internal cavity is a method of bending that causes the displacement at the surface where the internal cavity exists to be smaller than that when there is no internal cavity (distribution indicated by the broken line in the figure). Show. The three-dimensional spatial distribution information analysis unit 7 can determine the presence of an internal cavity from the obtained deflection state by storing this characteristic deflection method in advance.

Further, from the change in the movement amount in FIG. 26, the differential displacement calculation unit 5 can obtain a differential value obtained by spatially differentiating the movement amount that is the displacement. Since the differential value of the movement amount represents the strain in the Z direction, the characteristic difference between the strain in the Z direction when there is an internal cavity and the strain when there is no internal cavity is preliminarily determined in a three-dimensional spatial distribution information analysis unit. 7, the presence of the internal cavity can be determined from the strain in the Z direction.

Further, the time change information analysis unit 8 can determine deterioration such as aging from the time change of the movement amount. That is, when the structure ages, the period of change in the amount of movement when a load is applied becomes longer. Therefore, it is possible to determine that the structure has deteriorated by previously setting a threshold value for the period of change in the movement amount and when the period exceeds the threshold value. Further, it is possible to determine the deterioration in the same manner as described above by the period of change in the differential value of the movement amount.

FIG. 28 is a flowchart showing a state determination method of the state determination apparatus 1 of FIG.

In step S <b> 1, the displacement calculation unit 2 includes a frame image before application of a load that serves as a reference for calculating displacement in a time-series image of the surface of the structure 20 before and after applying a load imaged by the imaging device 11. Capture the frame images after applying the load in time series. At this time, when imaging the frame image before applying the load, the imaging device 11 performs imaging at the initial imaging distance L and imaging at a distance obtained by shifting the imaging distance by δ ′ by switching the optical path length control unit 12. Do. The displacement calculation unit 2 also captures these frame images.

The displacement calculation unit 2 calculates the displacement in the X and Y directions of the image after the load application with respect to the image before the load application as a reference in time series. Further, in the frame image before applying the load, the displacement in the X and Y directions of the image at a distance obtained by shifting the imaging distance with respect to the image at the initial imaging distance L by δ ′ is also calculated.

The displacement calculation unit 2 may be a displacement distribution diagram (contour lines of displacement) in which the calculated two-dimensional distribution of displacement is displayed on an XY plane. Further, the displacement calculation unit 2 inputs the calculated displacement or displacement distribution diagram to the depth movement amount calculation unit 3 and the displacement separation unit 4.

In step S2, the depth movement amount calculation unit 3 calculates the initial imaging distance L from the displacement in the X and Y directions of the image at a distance shifted by δ 'with respect to the image at the initial imaging distance L. Further, the depth movement amount calculation unit 3 determines the movement amount by which the structure 20 surface moves in the normal direction due to the deflection of the structure 20 due to a load from the displacement of the time-series image calculated by the displacement calculation unit 2. Calculation is performed using the calculated imaging distance L. At this time, the depth movement amount calculation unit 3 estimates the inclination angle formed by the optical axis of the imaging device 11 and the normal line of the surface of the structure 20, and calculates the movement amount in consideration of this inclination angle. The depth movement amount calculation unit 3 inputs the calculated movement amount to the displacement separation unit 4, the differential displacement calculation unit 5, and the abnormality determination unit 6.

In step S3, the displacement separation unit 4 calculates the out-of-plane displacement using the movement amount calculated by the depth movement amount calculation unit 3.

In step S4, the displacement separating unit 4 subtracts the out-of-plane displacement from the displacement obtained by the displacement calculating unit 2 to separate the in-plane displacement. That is, the displacement separation unit 4 calculates the in-plane displacement in the XY direction of the surface of the structure 20 after the load is applied with respect to the reference before the load is applied. Further, the calculated two-dimensional distribution of in-plane displacement may be a displacement distribution diagram (contour lines of displacement) displayed on the XY plane. The displacement separation unit 4 inputs the calculated result to the differential displacement calculation unit 5 and the abnormality determination unit 6.

In step S5, the differential displacement calculation unit 5 spatially differentiates the in-plane displacement or displacement distribution diagram input from the displacement separation unit 4 to calculate a differential displacement (stress value) or differential displacement distribution diagram (stress field). . Further, the differential displacement calculation unit 5 calculates a differential displacement (stress value) or a differential displacement distribution diagram (stress field) of the movement amount obtained by the depth movement amount calculation unit 3. The differential displacement calculation unit 5 inputs the calculated result to the abnormality determination unit 6.

The following steps S6, S7, S8, and S9 are steps in which the three-dimensional spatial distribution information analysis unit 7 of the abnormality determination unit 6 determines cracks, delamination, internal cavities, and deterioration that are defects in the structure. The determination method will be described with reference to the above-described pattern matching method and threshold value method.

In step S6, the three-dimensional spatial distribution information analysis unit 7 of the abnormality determination unit 6 determines the state of cracks, separation, and internal cavities from the input displacement or displacement distribution diagram in the X direction.

First, the determination method by pattern matching will be described. The three-dimensional spatial distribution information analysis unit 7 includes, as a database, displacement distribution patterns created in advance corresponding to cracks, internal cavities, widths and depths of separation as shown in FIGS. 18A, 20A, and 22A. ing. The three-dimensional spatial distribution information analysis unit 7 performs pattern matching by rotating and enlarging / reducing these displacement distribution patterns with respect to the displacement distribution diagram in the X direction input from the displacement separation unit 4 to detect defects in the XY plane. Can be determined.

Next, a determination method based on a displacement threshold will be described. The three-dimensional spatial distribution information analysis unit 7 determines, for example, the continuity of the displacement based on the input displacement in the X direction. That is, as shown in FIG. 11A, the presence or absence of continuity is determined based on the presence or absence of a steep change equal to or greater than the displacement threshold. The three-dimensional spatial distribution information analysis unit 7 determines that there is a possibility that a crack or separation may exist in any part of the XY plane when there is a steep change without continuity. While the continuous flag DisC (x, y, t) is set to 1, the displacement data at a place where there is a steep change is recorded as numerical information. Here, t is the time on the time-series image of the frame image captured in step S1.

The abnormality determination unit 6 inputs the defect information determined by pattern matching, or the discontinuity flag DisC (x, y, t) and numerical information determined by the displacement threshold to the abnormality map creation unit 9.

In step S7, the three-dimensional spatial distribution information analysis unit 7 of the abnormality determination unit 6 determines the state of cracks, separation, and internal cavities from the input displacement or displacement distribution diagram in the Y direction.

First, the determination method by pattern matching will be described. The two-dimensional spatial distribution information analysis unit 7 includes, as a database, displacement distribution patterns created in advance corresponding to cracks, internal cavities, widths and depths of separation, as shown in FIGS. 18B, 20B, and 22B. ing. The three-dimensional spatial distribution information analysis unit 7 performs pattern matching on the displacement distribution diagram in the Y direction input from the displacement separation unit 4 by rotating and enlarging / reducing these displacement distribution patterns, and in the XY plane. Determine the position and type of the defect.

Next, a determination method based on a displacement threshold will be described. If there are cracks, delamination and internal cavity defects, displacement also occurs in the Y direction. Therefore, if the three-dimensional spatial distribution information analysis unit 7 detects a displacement greater than a predetermined threshold value, it determines that the location is defective and sets the orthogonal flag ortho (x, y, t) to 1. At the same time, the displacement data of the location where the displacement greater than the threshold is detected is recorded as numerical information.

The abnormality determination unit 6 inputs the defect information determined by pattern matching, or the orthogonal flag ortho (x, y, t) and numerical information determined by displacement to the abnormality map creation unit 9.

In step S8, the three-dimensional spatial distribution information analysis unit 7 of the abnormality determination unit 6 determines the deterioration of the structure and the state of the defect from the input movement amount in the Z direction. The abnormality determination unit 6 inputs the determined deterioration and defect information to the abnormality map creation unit 9.

In step S9, the three-dimensional spatial distribution information analysis unit 7 of the abnormality determination unit 6 determines the state of cracks, separation, and internal cavities from the input differential displacement (stress value) or differential displacement distribution diagram (stress field). .

First, the determination method by pattern matching will be described. The three-dimensional spatial distribution information analysis unit 7 includes, as a database, displacement distribution patterns created in advance corresponding to cracks, internal cavities, widths and depths of separation as shown in FIGS. 18C, 20C, and 22C. ing. The three-dimensional spatial distribution information analysis unit 7 performs pattern matching on the differential displacement distribution diagram input from the differential displacement calculation unit 5 by rotating and enlarging / reducing these displacement distribution patterns, so that defects in the XY plane are detected. Determine the position and type.

Next, the determination method based on the differential displacement threshold will be described. For example, the strain in the X direction increases rapidly because the differential value of the displacement diverges at the cracked portion. From this, it is possible to determine that there is a crack at a location where a strain exceeding the threshold is detected by providing a threshold value in advance for the strain value. Based on the input differential displacement, the three-dimensional spatial distribution information analysis unit 7 determines that there is a crack at the location, sets 1 to the differential value flag Diff (x, y, t), and sets the defect location. Record differential displacement data as numerical information.

The abnormality determination unit 6 inputs the defect information determined by pattern matching, or the differential value flag Diff (x, y, t) and numerical information determined by differential displacement to the abnormality map creation unit 9.

In step S10, the displacement calculation unit 2 determines whether the processing of each frame image of the time series image has been completed. That is, when the number of frames of the time-series image is n, it is determined whether or not the n-th process is finished. If the number of processes is less than n (NO), the processes from step S1 are repeated. This is repeated until n sheets are completed. Note that n is not limited to the total number of frames, and can be set to an arbitrary number. When the process has finished n sheets (YES), the process proceeds to step S11.

In step S11, the time change information analysis unit 8 of the abnormality determination unit 6 generates a displacement time response as shown in FIG. 21B or FIG. 23 from the time-series displacement or displacement distribution diagram corresponding to the n frame images. To analyze. That is, from the n displacement distribution diagrams I (x, y, n), the time frequency distribution (the time frequency is assumed to be f) is the amplitude A (x, y, z, f) and the phase P (x, y, z). , F). The time change information analysis unit 8 determines that there is an internal cavity at a position where a phase shift occurs when the time frequency distribution has a characteristic in which the phase differs depending on the location as shown in FIG. 21B. Moreover, when the polarity of displacement is reversed as shown in FIG. In addition, the time change information analysis unit 8 compares the period of change in the movement amount in the Z direction and the period of change in the differential value of the movement amount with a predetermined threshold of the period, thereby aging the structure. Determine. The time change information analysis unit 8 inputs the above time frequency distribution calculation result and defect determination result to the abnormality map creation unit 9.

In step 12, the abnormality map creation unit 9 creates an abnormality map (x, y, z) based on the information input in the above steps. The results sent from the three-dimensional spatial distribution information analysis unit 7 and the time change information analysis unit 8 are data groups related to the point (x, y, z) on the XYZ coordinates. The state of the structure of these data is determined by the three-dimensional spatial distribution information analysis unit 7 and the time change information analysis unit 8 in the abnormality determination unit 6.

These determinations are made on the displacement or displacement distribution diagram in the X direction, the displacement or displacement distribution diagram in the Y direction, the movement amount in the Z direction, the differential displacement or differential displacement distribution diagram, and the time response of the displacement or differential displacement. . For this reason, the abnormality map creation unit 9 can determine whether the displacement in the X direction and the differential displacement are attached, even if data loss occurs, for example, the determination in the displacement in the Y direction cannot be made. -The state of the location in the Y coordinate can be determined. Based on this determination, an abnormality map (x, y, z) can be created.

Further, when determining the defect state, if the determination of the displacement in the X direction, the displacement in the Y direction, the displacement in the Z direction, and the differential displacement is different, it may be determined by majority vote. Alternatively, the item having the largest difference from the threshold value that is the criterion may be determined.

Also, the abnormality map creation unit 9 can express the degree of defects based on the various numerical information described above. For example, the width and depth of a crack, the dimension of peeling, the dimension of an internal cavity, the depth from the surface, and the like can be expressed.

In addition, the abnormality map creation unit 9 uses the abnormality map (x, y, z) to determine the defect state of the structure performed by the three-dimensional spatial distribution information analysis unit 7 and the time change information analysis unit 8 in the abnormality determination unit 6. It can also be done when creating. That is, analysis data may be obtained from the three-dimensional spatial distribution information analysis unit 7 and the time change information analysis unit 8, and the defect map generation unit 9 may determine the defect state based on the analysis data.

Also, the result output of the abnormality map creation unit 9 may be information in a form that can be directly visualized by a person with a display device, or information in a form that is read by a machine.

In the present embodiment, for example, the lens focal length of the imaging device 11 is 50 mm, the pixel pitch is 5 μm, and a pixel resolution of 500 μm can be obtained at an imaging distance of 5 m. The image pickup device 11 has a monochrome image pickup device with horizontal 2000 pixels and vertical 2000 pixels, and can capture a 1 m × 1 m range at an image pickup distance of 5 m. The frame rate of the image sensor can be 60 Hz.

Also, in the image correlation in the displacement calculation unit 2, sub-pixel displacement estimation by quadratic curve interpolation can be used so that displacement can be estimated up to 1/100 pixels and a displacement resolution of 5 μm can be obtained. The following various methods can be used for subpixel displacement estimation in image correlation. In addition, a smoothing filter can be used to reduce noise during differentiation in displacement differentiation.

補間 Interpolation by quadratic surface, equiangular line, etc. may be used for subpixel displacement estimation. In addition, for image correlation calculation, SAD (Sum of Absolute Difference) method, SSD (Sum of Squared Difference) method, NCC (Normalized Cross Correlation) method, ZNCC (Zero-mean Normalized) method, etc. May be. Any combination of these methods and the above-described subpixel displacement estimation method may be used.

In addition to image correlation calculation, optical flow calculation by the gradient method may be used for displacement estimation.

The imaging distance L and the deflection amount δ obtained by the depth movement amount calculation unit 3 may be output and input as reference values to other measuring instruments or the like.

The lens focal length of the imaging device 11, the pixel pitch of the imaging element, the number of pixels, and the frame rate may be appropriately changed according to the measurement target.

In the present embodiment, for example, a beam-like structure can correspond to a bridge, and a load can correspond to a traveling vehicle. In the above explanation, a load is applied to the beam-like structure. However, even when the load moves on the bridge like a traveling vehicle, it is possible to detect cracks, internal cavities, separation, and deterioration. is there. In addition, if the material exhibits the same behavior as described above in terms of material mechanics, a structure having other materials, sizes and shapes, or a load method different from loading the structure, for example, a load is suspended. It can also be applied to a load method such as lowering.

Moreover, as long as it can measure a time-series signal of a spatial two-dimensional distribution of the surface displacement of a structure, it is not limited to a time-series image, but an array-shaped laser Doppler sensor, an array-shaped strain gauge, an array-shaped vibration sensor. An array-type acceleration sensor or the like may be used. Spatial two-dimensional time-series signals obtained from these array sensors may be handled as image information.

In this embodiment, distance information and inclination information for calculating out-of-plane displacement due to movement of the structure surface in the normal direction can be acquired from images obtained by imaging the structure surface before and after applying a load. In principle, the amount of movement of the structure surface in the normal direction can be obtained by measuring the amount of deflection due to the load from the side surface direction of the structure. However, for example, when the structure is a bridge or the like, measurement from the side surface of the bridge is extremely difficult in work, and therefore the measurement accuracy is also lowered. Since this embodiment can also solve this problem in work, the displacement of the image on the structure surface can be corrected with high accuracy. Moreover, in this embodiment, since the apparatus and facility for measuring the amount of deflection | deviation from a side surface direction are also unnecessary, the increase in cost can be suppressed.

As described above, according to the state determination system 10, the imaging distance on the surface of the structure and the amount of movement in the normal direction of the surface of the structure due to the load application can be obtained. Furthermore, an out-of-plane displacement due to the movement of the surface of the structure in the normal direction can be obtained using the movement amount. By subtracting this out-of-plane displacement from the displacement caused by the load on the image of the structure surface, the in-plane displacement of the structure surface can be separated. According to the state determination apparatus 100, the above processing can be easily performed with good workability, and therefore, detection that distinguishes defects such as cracks, peeling, and internal cavities of the structure can be performed remotely and accurately with no contact. Is possible.

As described above, according to the present embodiment, it is possible to accurately detect defects such as cracks, peeling, and internal cavities of a structure from a remote location in a non-contact manner while suppressing costs.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention.

Moreover, although a part or all of said embodiment may be described also as the following additional remarks, it is not restricted to the following.
(Appendix 1)
A two-dimensional spatial distribution of the displacement of the image is calculated from the difference between the images of the structure surface at the first and second imaging distances, and the image of the structure surface before the load application at the first imaging distance and A displacement calculation unit that calculates a two-dimensional spatial distribution of displacement of the time-series image from a difference between the time-series images of the surface of the structure by applying a load;
The first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the image, and the movement amount in the normal direction of the structure surface due to the load application is calculated from the two-dimensional spatial distribution of the displacement of the time-series image. A depth movement amount calculation unit that calculates using an imaging distance of 1;
A displacement separation unit that calculates a correction amount based on the movement amount, subtracts the correction amount from the two-dimensional spatial distribution of displacement of the time-series image, and separates the two-dimensional spatial distribution of displacement of the structure surface;
An abnormality determination unit that identifies a defect in the structure based on a comparison between a two-dimensional spatial distribution of the displacement of the structure surface and the amount of movement, and a spatial distribution of the displacement provided in advance and a threshold relating to the amount of movement. And a state determination device.
(Appendix 2)
The state determination apparatus according to claim 1, wherein the depth movement amount calculation unit estimates an inclination angle of the structure from the time series image and calculates the movement amount corrected by the inclination angle.
(Appendix 3)
A differential displacement calculating unit that calculates a two-dimensional differential spatial distribution from the two-dimensional spatial distribution of the displacement of the structure surface, wherein the abnormality determining unit is configured to differentiate the two-dimensional differential spatial distribution and a differential displacement provided in advance; The state determination device according to

appendix

1 or 2, wherein a defect of the structure is specified based on a comparison with a spatial distribution.
(Appendix 4)
The state determination apparatus according to any one of appendices 1 to 3, wherein the abnormality determination unit identifies a defect of the structure based on a temporal change in a two-dimensional spatial distribution of displacement of the structure surface.
(Appendix 5)
The state determination apparatus according to appendix 3 or 4, wherein the abnormality determination unit specifies a defect of the structure based on a time change of the two-dimensional differential space distribution.
(Appendix 6)
The state determination according to any one of appendices 1 to 5, wherein the abnormality determination unit identifies a defect of the structure based on a comparison between a displacement of the surface of the structure and a predetermined threshold value. apparatus.
(Appendix 7)
The state according to any one of appendices 3 to 6, wherein the abnormality determination unit identifies a defect of the structure based on a comparison between a differential displacement of a displacement of the structure surface and a threshold value provided in advance. Judgment device.
(Appendix 8)
The state determination apparatus according to one of appendices 1 to 7, further including an abnormality map creation unit that creates an abnormality map indicating the location and type of the defect based on a determination result of the abnormality determination unit.
(Appendix 9)
9. The state determination device according to claim 1, wherein the type of the defect includes cracks, peeling, and internal cavities.
(Appendix 10)
The state determination device according to appendix 9, wherein the spatial distribution of the displacement provided in advance and the differential spatial distribution of the differential displacement provided in advance are based on information on the crack, the separation, and the internal cavity.
(Appendix 11)
11. The state determination device according to claim 1, wherein the two-dimensional spatial distribution includes an X-direction displacement distribution and a Y-direction displacement distribution on an XY plane of the displacement.
(Appendix 12)
The state determination device according to one of the supplementary notes 1 to 11,
A state determination system comprising: the time-series image; and an imaging device that captures the image and provides the image to the state determination device.
(Appendix 13)
The state determination system according to appendix 12, wherein the imaging apparatus includes an optical path length control unit that sets the first and second imaging distances.
(Appendix 14)
The state determination system according to appendix 13, wherein the optical path length control unit sets the first and second imaging distances by changing a refractive index in the optical path or switching an optical path.
(Appendix 15)
Calculating the two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances;
Calculating a two-dimensional spatial distribution of the displacement of the time-series image from the difference between the image of the structure surface before the load application at the first imaging distance and the time-series image of the structure surface by the load application;
Calculating the first imaging distance from a two-dimensional spatial distribution of the displacement of the image;
The amount of movement in the normal direction of the surface of the structure due to the application of the load is calculated from the two-dimensional spatial distribution of the displacement of the time series image using the first imaging distance,
A correction amount is calculated based on the movement amount,
Subtracting the correction amount from the two-dimensional spatial distribution of the displacement of the time series image to separate the two-dimensional spatial distribution of the displacement of the structure surface;
State determination that identifies a defect in the structure based on a comparison between a two-dimensional spatial distribution of the displacement of the structure surface and the amount of movement, and a spatial distribution of displacement provided in advance and a threshold value related to the amount of movement. Method.
(Appendix 16)
The state determination method according to claim 15, wherein an inclination angle of the structure is estimated from the time series image, and the movement amount corrected by the inclination angle is calculated.
(Appendix 17)
Calculating a two-dimensional differential spatial distribution of the two-dimensional spatial distribution from the two-dimensional spatial distribution;
The state determination method according to appendix 15 or 16, wherein a defect of the structure is specified based on a comparison between the two-dimensional differential space distribution and a differential space distribution of differential displacement provided in advance.
(Appendix 18)
18. The state determination method according to one of appendices 15 to 17, wherein a defect of the structure is specified based on a temporal change in the two-dimensional spatial distribution.
(Appendix 19)
The state determination method according to appendix 17 or 18, wherein a defect of the structure is specified based on a time change of the two-dimensional differential space distribution.
(Appendix 20)
20. The state determination method according to any one of appendices 15 to 19, wherein a defect of the structure is specified based on a comparison between a displacement of the structure surface displacement and a predetermined threshold.
(Appendix 21)
21. The state determination method according to any one of appendices 17 to 20, wherein a defect of the structure is specified based on a comparison between a differential displacement of the displacement of the structure surface and a threshold provided in advance.
(Appendix 22)
The state determination method according to any one of supplementary notes 15 to 21, wherein an abnormality map indicating the location and type of the defect is created based on the determination result.
(Appendix 23)
23. The state determination method according to one of appendices 15 to 22, wherein the type of the defect includes cracks, peeling, and internal cavities.
(Appendix 24)
The state determination method according to appendix 23, wherein the spatial distribution of the displacement provided in advance and the differential spatial distribution of the differential displacement provided in advance are based on information on the crack, the separation, and the internal cavity.
(Appendix 25)
25. The state determination method according to any one of appendices 15 to 24, wherein the two-dimensional spatial distribution includes an X-direction displacement distribution and a Y-direction displacement distribution on an XY plane of the displacement.
(Appendix 26)
A two-dimensional spatial distribution of the displacement of the image is calculated from the difference between the images of the structure surface at the first and second imaging distances, and the image of the structure surface before the load application at the first imaging distance and A displacement calculation unit that calculates a two-dimensional spatial distribution of displacement of the time-series image from a difference between the time-series images of the surface of the structure by applying a load;
The first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the image, and the movement amount in the normal direction of the structure surface due to the load application is calculated from the two-dimensional spatial distribution of the displacement of the time-series image. A depth movement amount calculation unit that calculates using an imaging distance of 1;
The state determination apparatus which has an abnormality determination part which specifies the defect of the said structure based on the comparison with the threshold value regarding the said movement amount with which the said movement amount was equipped previously.
(Appendix 27)
27. The state determination device according to appendix 26, wherein the depth movement amount calculation unit estimates an inclination angle of the structure from the time series image and calculates the movement amount corrected by the inclination angle.
(Appendix 28)
A differential displacement calculating unit configured to calculate a differential displacement of the movement amount, and the abnormality determination unit detects defects in the structure based on a comparison between the differential displacement of the movement amount and a differential displacement provided in advance. The state determination device according to appendix 26 or 27, which is specified.
(Appendix 29)
A displacement separation unit is provided that calculates a correction amount based on the movement amount, subtracts the correction amount from the two-dimensional spatial distribution of the displacement of the time-series image, and separates the two-dimensional spatial distribution of the displacement of the structure surface. The abnormality determining unit identifies defects of the structure based on a comparison between a two-dimensional spatial distribution of the displacement of the structure surface and a spatial distribution of the displacement provided in advance. The state determination apparatus according to claim 1.
(Appendix 30)
The differential displacement calculation unit calculates a two-dimensional differential spatial distribution from the two-dimensional spatial distribution of the displacement of the structure surface, and the abnormality determination unit calculates the differential displacement of the differential displacement provided in advance and the two-dimensional differential spatial distribution. The state determination apparatus according to appendix 28 or 29, wherein a defect of the structure is specified based on a comparison with a spatial distribution.
(Appendix 31)
The state determination according to any one of appendices 26 to 30, wherein the abnormality determination unit identifies a defect of the structure based on a time change of the two-dimensional spatial distribution of the movement amount or the displacement of the structure surface. apparatus.
(Appendix 32)
32. The state determination device according to any one of appendices 28 to 31, wherein the abnormality determination unit specifies a defect of the structure based on a temporal change in the differential displacement of the movement amount or the two-dimensional differential space distribution.
(Appendix 33)
33. The state determination device according to any one of appendices 26 to 32, further including an abnormality map creation unit that creates an abnormality map indicating the location and type of the defect based on a determination result of the abnormality determination unit.
(Appendix 34)
Calculating the two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances;
Calculating a two-dimensional spatial distribution of the displacement of the time-series image from the difference between the image of the structure surface before the load application at the first imaging distance and the time-series image of the structure surface by the load application;
Calculating the first imaging distance from a two-dimensional spatial distribution of the displacement of the image;
The amount of movement in the normal direction of the surface of the structure due to the application of the load is calculated from the two-dimensional spatial distribution of the displacement of the time series image using the first imaging distance,
A state determination method for identifying a defect in the structure based on a comparison between the movement amount and a threshold value relating to the movement amount provided in advance.
(Appendix 35)
35. The state determination method according to appendix 34, wherein an inclination angle of the structure is estimated from the time series image, and the movement amount corrected by the inclination angle is calculated.
(Appendix 36)
Calculating a differential displacement of the amount of movement;
36. The state determination method according to appendix 34 or 35, wherein a defect of the structure is specified based on a comparison between the differential displacement of the movement amount and a differential displacement provided in advance.
(Appendix 37)
Calculating a correction amount based on the movement amount, subtracting the correction amount from a two-dimensional spatial distribution of the displacement of the time-series image, and separating a two-dimensional spatial distribution of the displacement of the structure surface;
37. The state determination according to any one of appendices 34 to 36, wherein a defect of the structure is specified based on a comparison between a two-dimensional spatial distribution of displacement of the structure surface and a spatial distribution of displacement provided in advance. Method.
(Appendix 38)
Calculating a two-dimensional differential spatial distribution from the two-dimensional spatial distribution of the displacement of the structure surface;
38. The state determination method according to appendix 37, wherein a defect of the structure is specified based on a comparison between the two-dimensional differential space distribution and a differential space distribution of differential displacement provided in advance.
(Appendix 39)
39. A state determination method according to any one of appendices 34 to 38, wherein a defect of the structure is specified based on a temporal change in the two-dimensional spatial distribution of the movement amount or the displacement of the structure surface.
(Appendix 40)
40. The state determination method according to any one of appendices 36 to 39, wherein a defect of the structure is specified based on a temporal change in the differential displacement of the movement amount or the two-dimensional differential space distribution.
(Appendix 41)
41. The state determination method according to any one of appendices 44 to 40, wherein an abnormality map indicating the location and type of the defect is created.
This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2016-081837 for which it applied on April 15, 2016, and takes in those the indications of all here.

DESCRIPTION OF SYMBOLS 1,100 State determination apparatus 2,101 Displacement calculation part 3,102 Depth movement amount calculation part 4,103 Displacement separation part 5 Differential displacement calculation part 6,104 Abnormality determination part 7 Three-dimensional spatial distribution information analysis part 8 Time change information analysis Unit 9 Abnormal map creation unit 10 State determination system 11, 11a, 11b,

11c Imaging device

12, 12a, 12b, 12c Optical path length control unit 12a1 Parallel plate glass 12a2 Movable mechanism 12b1 Mirror 12b2 Movable mechanism 12c1 Half mirror 12c2 Mirror 13 Lens 14 Image sensor 15 Processing circuit 20 Structure 21 Defect

Claims

A two-dimensional spatial distribution of the displacement of the image is calculated from the difference between the images of the structure surface at the first and second imaging distances, and the image of the structure surface before the load application at the first imaging distance and A displacement calculating means for calculating a two-dimensional spatial distribution of the displacement of the time-series image from a difference between the time-series images of the surface of the structure by applying a load;
The first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the image, and the movement amount in the normal direction of the structure surface due to the load application is calculated from the two-dimensional spatial distribution of the displacement of the time-series image. Depth movement amount calculating means for calculating using the imaging distance of 1;
Displacement separation means for calculating a correction amount based on the movement amount, subtracting the correction amount from a two-dimensional spatial distribution of the displacement of the time-series image, and separating the two-dimensional spatial distribution of the displacement of the structure surface;
Abnormality determination means for identifying a defect in the structure based on a comparison between a two-dimensional spatial distribution of displacement of the structure surface and the amount of movement, and a spatial distribution of displacement provided in advance and a threshold value related to the amount of movement. And a state determination device.
The state determination apparatus according to claim 1, wherein the depth movement amount calculation means estimates an inclination angle of the structure from the time-series image and calculates the movement amount corrected by the inclination angle.
Differential displacement calculating means for calculating a two-dimensional differential spatial distribution from the two-dimensional spatial distribution of the displacement of the structure surface, and the abnormality determining means includes the two-dimensional differential spatial distribution and a differential displacement derivative provided in advance. The state determination apparatus according to claim 1 or 2, wherein a defect of the structure is specified based on a comparison with a spatial distribution.
4. The state determination apparatus according to claim 1, wherein the abnormality determination unit specifies a defect of the structure based on a temporal change of a two-dimensional spatial distribution of a displacement of the structure surface.
The state determination device according to claim 3 or 4, wherein the abnormality determination unit specifies a defect of the structure based on a time change of the two-dimensional differential space distribution.
The state according to claim 1, wherein the abnormality determination unit specifies a defect of the structure based on a comparison between a displacement of the surface of the structure and a threshold value provided in advance. Judgment device.
The said abnormality determination means specifies the defect of the said structure based on the comparison with the differential displacement of the displacement of the said structure surface, and the threshold value provided beforehand, The one of Claim 3-6 State determination device.
8. The state determination apparatus according to claim 1, further comprising an abnormality map creating unit that creates an abnormality map indicating the location and type of the defect based on a determination result of the abnormality determination unit.
9. The state determination device according to claim 1, wherein the type of the defect includes cracking, peeling, and internal cavity.
The state determination device according to claim 9, wherein the spatial distribution of the displacement provided in advance and the differential spatial distribution of the differential displacement provided in advance are based on information on the crack, the separation, and the internal cavity.
11. The state determination apparatus according to claim 1, wherein the two-dimensional spatial distribution includes an X-direction displacement distribution and a Y-direction displacement distribution on the XY plane of the displacement.
A state determination device according to one of claims 1 to 11, and
A state determination system comprising: the time-series image; and an imaging device that captures the image and provides the image to the state determination device.
The state determination system according to claim 12, wherein the imaging apparatus includes an optical path length control unit that sets the first and second imaging distances.
14. The state determination system according to claim 13, wherein the optical path length control means sets the first and second imaging distances by changing the refractive index in the optical path or switching the optical path.
Calculating the two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances;
Calculating a two-dimensional spatial distribution of the displacement of the time-series image from the difference between the image of the structure surface before the load application at the first imaging distance and the time-series image of the structure surface by the load application;
Calculating the first imaging distance from a two-dimensional spatial distribution of the displacement of the image;
The amount of movement in the normal direction of the surface of the structure due to the application of the load is calculated from the two-dimensional spatial distribution of the displacement of the time series image using the first imaging distance,
A correction amount is calculated based on the movement amount,
Subtracting the correction amount from the two-dimensional spatial distribution of the displacement of the time series image to separate the two-dimensional spatial distribution of the displacement of the structure surface;
State determination that identifies a defect in the structure based on a comparison between a two-dimensional spatial distribution of the displacement of the structure surface and the amount of movement, and a spatial distribution of displacement provided in advance and a threshold value related to the amount of movement. Method.
The state determination method according to claim 15, wherein an inclination angle of the structure is estimated from the time-series image, and the movement amount corrected by the inclination angle is calculated.
Calculating a two-dimensional differential spatial distribution of the two-dimensional spatial distribution from the two-dimensional spatial distribution;
The state determination method according to claim 15 or 16, wherein a defect of the structure is specified based on a comparison between the two-dimensional differential space distribution and a differential space distribution of differential displacement provided in advance.
The state determination method according to claim 15, wherein a defect of the structure is specified based on a time change of the two-dimensional spatial distribution.
The state determination method according to claim 17 or 18, wherein a defect of the structure is specified based on a time change of the two-dimensional differential space distribution.
20. The state determination method according to claim 15, wherein a defect of the structure is specified based on a comparison between a displacement of the surface of the structure and a predetermined threshold value.
21. The state determination method according to claim 17, wherein a defect of the structure is specified based on a comparison between a differential displacement of a displacement of the structure surface and a threshold value provided in advance.
The state determination method according to any one of claims 15 to 21, wherein an abnormality map indicating the location and type of the defect is created based on the determination result.
23. The state determination method according to claim 15, wherein the types of defects include cracks, peeling, and internal cavities.
The state determination method according to claim 23, wherein the spatial distribution of the displacement provided in advance and the differential spatial distribution of the differential displacement provided in advance are based on information on the crack, the separation, and the internal cavity.
25. The state determination method according to claim 15, wherein the two-dimensional spatial distribution includes an X-direction displacement distribution and a Y-direction displacement distribution on an XY plane of the displacement.
A two-dimensional spatial distribution of the displacement of the image is calculated from the difference between the images of the structure surface at the first and second imaging distances, and the image of the structure surface before the load application at the first imaging distance and A displacement calculating means for calculating a two-dimensional spatial distribution of the displacement of the time-series image from a difference between the time-series images of the surface of the structure by applying a load;
The first imaging distance is calculated from the two-dimensional spatial distribution of the displacement of the image, and the movement amount in the normal direction of the structure surface due to the load application is calculated from the two-dimensional spatial distribution of the displacement of the time-series image. Depth movement amount calculating means for calculating using the imaging distance of 1;
The state determination apparatus which has the abnormality determination means which specifies the defect of the said structure based on the comparison with the threshold value regarding the said movement amount with which the said movement amount was equipped previously.
27. The state determination device according to claim 26, wherein the depth movement amount calculation means estimates an inclination angle of the structure from the time-series image and calculates the movement amount corrected by the inclination angle.
Differential displacement calculating means for calculating a differential displacement of the movement amount, and the abnormality determining means detects defects in the structure based on a comparison between the differential displacement of the movement amount and a differential displacement provided in advance. The state determination device according to claim 26 or 27, wherein the state determination device is specified.
Displacement means for calculating a correction amount based on the movement amount and subtracting the correction amount from a two-dimensional spatial distribution of the displacement of the time-series image to separate the two-dimensional spatial distribution of the displacement of the structure surface is provided. The abnormality determination means identifies a defect of the structure based on a comparison between a two-dimensional spatial distribution of displacement of the structure surface and a spatial distribution of displacement provided in advance. The state determination apparatus according to claim 1.
The differential displacement calculating means calculates a two-dimensional differential spatial distribution from the two-dimensional spatial distribution of the displacement of the structure surface, and the abnormality determining means calculates the two-dimensional differential spatial distribution and a differential displacement provided in advance. 30. The state determination device according to claim 28 or 29, wherein a defect of the structure is specified based on a comparison with a spatial distribution.
The state according to any one of claims 26 to 30, wherein the abnormality determination unit specifies a defect in the structure based on a temporal change in the two-dimensional spatial distribution of the movement amount or the displacement of the structure surface. Judgment device.
32. The state determination device according to claim 28, wherein the abnormality determination unit specifies a defect of the structure based on a temporal change in the differential displacement of the movement amount or the two-dimensional differential space distribution. .
33. The state determination device according to claim 26, further comprising an abnormality map creation unit that creates an abnormality map indicating the location and type of the defect based on a determination result of the abnormality determination unit.
Calculating the two-dimensional spatial distribution of the displacement of the image from the difference between the images of the structure surface at the first and second imaging distances;
Calculating a two-dimensional spatial distribution of the displacement of the time-series image from the difference between the image of the structure surface before the load application at the first imaging distance and the time-series image of the structure surface by the load application;
Calculating the first imaging distance from a two-dimensional spatial distribution of the displacement of the image;
The amount of movement in the normal direction of the surface of the structure due to the application of the load is calculated from the two-dimensional spatial distribution of the displacement of the time series image using the first imaging distance,
A state determination method for identifying a defect in the structure based on a comparison between the movement amount and a threshold value relating to the movement amount provided in advance.
The state determination method according to claim 34, wherein an inclination angle of the structure is estimated from the time-series image, and the movement amount corrected by the inclination angle is calculated.
Calculating a differential displacement of the amount of movement;
36. The state determination method according to claim 34, wherein a defect of the structure is specified based on a comparison between a differential displacement of the movement amount and a differential displacement provided in advance.
Calculating a correction amount based on the movement amount, subtracting the correction amount from a two-dimensional spatial distribution of the displacement of the time-series image, and separating a two-dimensional spatial distribution of the displacement of the structure surface;
37. The state according to claim 34, wherein a defect of the structure is identified based on a comparison between a two-dimensional spatial distribution of displacement of the structure surface and a spatial distribution of displacement provided in advance. Judgment method.
Calculating a two-dimensional differential spatial distribution from the two-dimensional spatial distribution of the displacement of the structure surface;
38. The state determination method according to claim 37, wherein a defect of the structure is specified based on a comparison between the two-dimensional differential space distribution and a differential space distribution of differential displacement provided in advance.
The state determination method according to any one of claims 34 to 38, wherein a defect of the structure is specified based on a time change of the two-dimensional spatial distribution of the movement amount or the displacement of the structure surface.
40. The state determination method according to claim 36, wherein a defect of the structure is specified based on a temporal change in the differential displacement of the movement amount or the two-dimensional differential space distribution.
41. The state determination method according to claim 44, wherein an abnormality map indicating the location and type of the defect is created.