JP2011117824A - Apparatus and method for evaluation of strength - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform efficient and wide-range evaluation on the strength of a structure by a simple constitution. <P>SOLUTION: The strength evaluation apparatus includes: a light irradiation unit 201 for irradiating an area to be evaluated of a specimen 23; an imaging unit 202 for acquiring images of the area to be evaluation of the specimen 23 under the illumination; an image creation unit for comparing images of the area to be evaluated prior to the application of a load with images of the area to be evaluated after the application of the load and creating a difference image of luminance; a first graph creation unit for creating a first graph indicting pixels in a horizontal axis and luminance differences in a vertical axis by sequentially scanning pixels of interest in the difference image and reading each luminance difference of the pixels of interest; a signal conversion unit for converting the first graph into a second graph, a frequency domain graph; and an evaluation unit for evaluating the strength of the region to be evaluated of the specimen 23 on the basis of the second graph. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a strength evaluation apparatus and a strength evaluation method for evaluating the strength of a structure.

  As one of the soundness evaluations for evaluating the structural soundness of a structure, strength evaluation is performed by applying a predetermined load to the structure and measuring the displacement and strain of the structure at that time. Usually, sensors such as strain gauges and displacement meters are used for measuring strain and displacement.

JP 2000-055797 A

  However, when a region for strength evaluation is wide, such as a large structure, sensors such as strain gauges and displacement meters must be attached to the entire strength evaluation region, and many sensors are required. For this reason, there existed problems, such as the structure for evaluation becoming complicated. In addition, since it is impossible to attach a sensor to the entire structure, it is impossible to measure the behavior when a load is applied to a part where the sensor is not attached, causing problems such as unevenness in the measurement part. .

  The present invention has been made in view of such circumstances, and provides a strength evaluation apparatus and a strength evaluation method capable of efficiently performing a strength evaluation over a wide range of a structure with a simple configuration. Objective.

In order to solve the above problems, the present invention employs the following means.
The present invention relates to a strength evaluation apparatus for evaluating the strength of an evaluation target area in the specimen when a load is applied to the specimen, the light irradiation means for irradiating light to the evaluation target area of the specimen, and illumination The imaging means for acquiring the image of the evaluation target area of the specimen below, the image of the evaluation target area before applying the load and the image of the evaluation target area after applying the load are compared, and a luminance difference image is obtained. An image creation means to be created and a pixel of interest or a pixel of interest on the horizontal axis by sequentially scanning a pixel of interest or a region of interest consisting of a predetermined number of pixels in the difference image and reading the luminance difference of the pixel of interest or the region of interest A first graph creating means for creating a first graph showing a luminance difference on the vertical axis of the region, a signal converting means for converting the first graph into a second graph which is a graph in the frequency domain, and the second graph Zui, the provide strength evaluation apparatus comprising an evaluation means for evaluating the intensity of the evaluation target area in the specimen.

  According to such a configuration, an image of the evaluation target area of the specimen is acquired by the imaging unit from the start to the end of the strength test in which a load is applied to the specimen. And the difference image of a brightness | luminance is created by comparing the image of the specimen before applying a load, and the image of the specimen after a load addition, and a 1st graph is created based on this difference image of a brightness | luminance. . Since the first graph shows the position of each pixel when the pixel is scanned in the difference image according to a predetermined condition and the luminance difference at the position, the first graph is regarded as a signal indicating a change in the luminance difference in the evaluation target region. be able to. In addition, when the distortion occurs in the evaluation target area, the luminance of the image changes due to the irregular reflection of the part, so this first graph shows the behavior of the distortion generated in the evaluation target area when a load is applied to the specimen. It can be handled as a signal. In addition, in the first graph, when distortion occurs, the frequency changes in that portion. Therefore, by converting the first graph into a signal in the frequency domain to reveal the tendency of frequency change, and evaluating the intensity based on the second graph that is the graph in this frequency domain, the evaluation target region can be evaluated with higher accuracy. It becomes possible to evaluate the state of strain.

  In the strength evaluation apparatus, the evaluation unit determines a degree of distortion of the evaluation target region based on a ratio between an area of a predetermined mode and an area of another mode in the second graph, and the predetermined mode. May be determined based on the tendency of the strain of interest.

Thereby, the degree of distortion in the evaluation target region can be easily determined. In addition, since the state of the frequency change that occurs in the first graph changes depending on the tendency of the strain that occurs in the evaluation target area, for example, the direction and interval in which the strain occurs, By determining a predetermined mode of interest, it is possible to more accurately determine the state of distortion.
For example, when buckling is detected, a certain position is recessed (or swells), and therefore, determination may be made by paying attention to the primary mode.

  In the strength evaluation apparatus, the specimen has a shape in which panels of a predetermined size are connected in a substantially cylindrical shape, and the imaging unit is configured to evaluate the evaluation among a plurality of panels constituting the specimen. At least one unit is arranged so that the entire area corresponding to the target area can be photographed. The first graph creating means creates the first graph in units of panels, and the evaluation means is created in units of panels. It is also possible to determine whether or not the second graph is buckled in units of panels and output the number of the panels determined to be buckled as an evaluation result.

  As described above, when the evaluation target region is formed by a plurality of panels, the strength evaluation of the evaluation target region is easily performed by determining the presence or absence of buckling for each panel and counting the number of buckled panels. Can be performed.

  In the above-described strength evaluation apparatus, it is preferable that a plurality of the illuminating units are arranged radially above or below the specimen.

  By arranging the proving means in this way, the specimen can be illuminated evenly with substantially the same illuminance, and a local luminance difference in the evaluation target area can be eliminated.

  The present invention is a strength evaluation method for evaluating the strength of an evaluation target region in a specimen when a load is applied to the specimen, wherein the specimen is irradiated with light, and an image of the specimen under illumination is obtained. An image acquisition process for acquiring, an image generation process for comparing the image of the specimen before applying a load with the image of the specimen after applying a load, and creating a difference image of luminance, and a target pixel in the difference image Alternatively, a first graph in which a pixel of interest or a region of interest is plotted on the horizontal axis and a luminance difference is plotted on the vertical axis by sequentially scanning a region of interest having a predetermined number of pixels and reading the luminance difference of the pixel of interest or the region of interest. A first graph creating process for creating a signal, a signal converting process for converting the first graph into a second graph which is a frequency domain graph, and the strength of the evaluation target region in the specimen based on the second graph Provide strength evaluation method including an evaluation step of evaluating.

  According to the present invention, there is an effect that strength evaluation over a wide range of a structure can be efficiently performed with a simple configuration.

It is a side view which shows schematic structure of the space station transport machine which is the object of strength evaluation. It is a perspective view which shows the whole schematic structure of a non-pressurization carrier. It is a longitudinal cross-sectional view which shows the condition which assembled | attached the test body to the load addition apparatus. FIG. 4 is a plan view of FIG. 3. It is XX sectional drawing of FIG. It is the figure which showed schematic structure of the strength evaluation apparatus which concerns on one Embodiment of this invention. It is the figure which showed the example of arrangement | positioning of a light irradiation unit. It is the functional block diagram which expanded and showed the function with which a calculation unit is provided. It is the figure which showed an example of the image acquired by each camera of an imaging unit. FIG. 10 is a diagram illustrating an image generated by performing predetermined image processing on the image illustrated in FIG. 9. It is the figure which showed an example of the scanning order of the attention pixel. It is the figure which showed an example of the 1st graph. It is the figure which showed an example of the 2nd graph. It is the figure which showed an example of the relationship between the load given to the test body in the intensity | strength test, and the number of buckling panels.

  Hereinafter, an embodiment of a strength evaluation apparatus and a strength evaluation method according to the present invention will be described with reference to the drawings.

[Specimen and load application device]
First, a structure (specimen) that is an object of strength evaluation by the strength evaluation apparatus according to the present embodiment and a load applying device that applies a load to the specimen will be described.
FIG. 1 is a side view showing a schematic configuration of a space station transport vehicle (HTV) 1 that is an object of strength evaluation.

The HTV 1 is a cylindrical structure having a total length of about 10 m and a diameter of about 4 m. The HTV 1 is launched by a rocket and moves by itself in the outer space to dock with the space station.
The HTV1 delivers up to 6 tons of supplies such as food, clothing, and various experimental equipment to the space station. After the replenishment, load unnecessary items such as used experimental equipment and used clothing, and re-enter the atmosphere. storm in.

The HTV 1 includes a pressurized carrier 3 that carries materials used onboard the space station, a non-pressurized carrier 5 that carries materials used outside the ship, an electric module 7 that controls the HTV 1, and a power source. A propulsion module 9 is provided.
The pressurizing carrier 3 is provided with a hatch portion 11 that docks with the space station. The interior of the pressurized carrier 3 is maintained at about 1 atm, the same as that on the ground, from launch to connection to the space station. During connection with the space station, the space station occupant supplies materials via the hatch portion 11. Unloading and unloading of unused items are performed.

The non-pressurized carrier 5 has a substantially cylindrical shape, and a cargo tray called an exposure pallet is mounted inside. The experimental equipment used outside the ship is transported in a state of being mounted on the exposure pallet, taken out by the robot arm of the space station, and installed at a predetermined location.
The non-pressurized carrier 5 is provided with a pallet table 13 on which the exposure pallet is mounted, and an opening 15 for withdrawing and inserting the exposure pallet.

FIG. 2 is a perspective view showing an overall schematic structure of the non-pressurized carrier 5.
The main structure (primary structure) of the non-pressurized carrier 5 is a semi-monocoque structure in which the panel 17 is supported by a stringer 19 and a frame 21 as shown in FIG.
The panel 17 is a thin plate having a substantially cylindrical shape, and is made of, for example, an aluminum alloy.

The panel 17 mainly receives a load in the axial direction of the non-pressurized carrier 5 (that is, the HTV 1) and a direction orthogonal to the axial direction (rolling acceleration). The panel 17 is designed to withstand axial stress and shear stress due to these loads, but because of the severe demands for weight reduction, it has a design that allows buckling in the elastic region, that is, a post buckling design. It is a flexible structure.
The panel 17 after buckling forms an incomplete tension field for the load (shear load) perpendicular to the shaft ship by load redistribution to the stringer for the axial load, and is not pressurized. The carrier 5 is configured to withstand a load perpendicular to the axial direction of the carrier 5 but does not cause permanent deformation (residual strain).
Further, the region near the part connected to the stringer 19 also contributes to transmission of the axial load.

The stringer 19 is a mold member that is attached to the outer peripheral surface side of the panel 17 so as to extend in the axial direction of the non-pressurized carrier 5 (that is, the HTV 1). A plurality of, for example, 48 stringers 19 are attached on the periphery of the panel 17 at intervals.
The stringer 19 has a function of transmitting the most severe compressive load in the axial direction.

The frame 21 has a donut shape and is attached to the inner peripheral surface side of the panel 17 so as to extend in the circumferential direction. A plurality of, for example, five frames 21 are attached at intervals in the axial direction of the non-pressurized carrier 5.
The frame 21 is a member whose main purpose is to maintain rigidity in order to facilitate load transmission by the panel 17 and the stringer 19. The number, arrangement, and cross-sectional shape of the frames 21 are set so as to maintain the rigidity of the non-pressurized carrier 5.

Although the main structure of the non-pressurized carrier 5 has been described above, the main structures of the pressurized carrier 3, the electric module 7, and the propulsion module 9 are also substantially the same.
The stringers 19 are disposed in substantially the same circumferential direction through the pressurized carrier 3, the non-pressurized carrier 5, the electric module 7, and the propulsion module 9.

Since the periphery of the opening 15 is exposed to severe concentrated loads, various reinforcements are made.
For example, on both sides of the opening 15, longitudinal members (Longiron) having strength and rigidity equivalent to 10 times or more of the stringer 19 of the general part are arranged. Moreover, the panel 17 arrange | positioned in the same area | region is made into the board thickness 3 times or more of a general site | part so that no buckling may be accept | permitted. Further, a reinforcing bracket (gusset) for relaxing stress concentration is disposed at the corner portion of the opening 15.

  As shown in FIG. 2, the pallet stand 13 has a hollow truncated cone shape, and is provided with a mounting portion for attaching the exposure pallet to the end of the small diameter portion located at the upper position when launched.

Inside the electric module 7, an induction control system, a power supply system, a communication data processing system, and a communication system electronic device are mounted as secondary structures.
The propulsion module 9 is equipped with a total of 32 rocket engines and fuel tanks as secondary structures. The propulsion module 9 uses these rocket engines to change the trajectory of the HTV 1 after separating the rocket, or to freely adjust the direction according to a command from the electric module 7 and perform a meeting flight with the space station.

  Next, a load applying device for applying a load will be described for the main structure of the non-pressurized carrier 5 and the electric module 7 of the HTV 1. Since the HTV 1 has almost no load when it enters the outer space, there is a problem whether it has a structure that can withstand the load at the time of launch.

FIG. 3 is a longitudinal sectional view showing a state in which the specimen 23 is assembled to the load applying device 25. FIG. 4 is a plan view of FIG. 5 is a cross-sectional view taken along the line XX of FIG.
The specimen 23 includes a pressurizing portion dummy 27 that is a dummy structure of the pressurizing carrier 3, a non-pressurizing portion 29 that uses the actual structure of the non-pressurizing carrier 5, and an electric module portion 31 that uses the actual structure of the electric module 7. And the propulsion module dummy 33 which is the dummy structure of the propulsion module 9 is joined in the vertical direction in this order.

  The specimen 23 has a substantially cylindrical shape with a height of about 8 m and a diameter of about 4 m. In the specimen 23, for example, the thickness of the panel that mainly handles the horizontal load orthogonal to the axial direction is as thin as about 1 mm. This is a so-called soft structure.

An exposure pallet dummy 35, which is a dummy structure of the exposure pallet, is mounted on the pallet table 15 provided inside the non-pressurizing portion 29.
The exposed pallet dummy 35 has a mounting portion 37 that is a rectangular plate fixedly attached to the pallet stand 13 and a pallet loading point having a hollow cylindrical shape that extends through the mounting portion 37 in the vertical direction. A portion 39 and four support plates 41 that hold the pallet load point portion 39 and reinforce the attachment portion 37 are provided.

The pallet load point portion 39 is installed such that the axis center thereof substantially coincides with the axis center of the non-pressurizing portion 29.
The support plate 41 is a plate member having a substantially triangular shape. The support plates 41 are respectively arranged from the four corners of the attachment portion 37 toward the central axis of the pallet load point portion 39. One side of the support plate 41 is fixed to the upper portion of the attachment portion 37 so that the surface portion extends in the vertical direction, and the other side is fixed to the outer peripheral portion of the pallet load point 39.

An electric module secondary structure dummy 43 that simulates various electronic devices stored in the electric module 7 is provided inside the electric module unit 31.
The electrical module secondary structure dummy 43 includes an attachment portion 45 and an electronic equipment load point portion 47 having a hollow cylindrical shape extending through the attachment portion 45 in the vertical direction.
The attachment portion 45 is a substantially circular plate member, and an outer peripheral end thereof is attached to the panel 17. The upper surface of the attachment portion 45 is reinforced by a plurality of mold members arranged radially.
The electronic equipment load point portion 47 is installed such that the axis center thereof substantially coincides with the axis center of the non-pressurizing portion 29.

The propulsion module dummy 33 is fixedly attached to the floor surface 49.
A pressurizing load point 51 having a substantially cylindrical shape is provided at the upper end portion of the pressurizing portion dummy 27. The pressurized load point 51 is installed such that its axis center substantially coincides with the axis center of the non-pressurized portion 29.

  The load applying device 25 includes an axial load load portion 53 that loads a load in the axial direction of the non-pressurizing portion 29 and a first horizontal load load portion 55 that loads a load in a horizontal direction substantially orthogonal to the axial direction. And the 2nd horizontal direction load load part 57 and the control part 59 are provided.

  The axial load portion 53 is installed in the internal space of the specimen 23. The axial load load portion 53 includes a mounting base 61 fixedly attached to the floor 49, a pressurized vertical load load member 63 attached to the upper surface of the mounting base 61, a pair of pallet vertical load load members 65, and A pair of electronic device vertical load load members 67 is provided.

The pressurized vertical load loading member 63 is installed so as to extend in the axial direction at the axial center position of the specimen 23, and applies a load to the pressurized load point 51 in the axial direction of the specimen 23. .
The pressurized vertical load load member 63 has a hydraulic jack 69 whose lower end is swingably attached to the mounting base 61, and one end attached to a piston rod of the hydraulic jack 69, and an electronic equipment load point 47 and a pallet load point. A load load rod 71 whose other end is swingably attached to the pressurized load point 51 through the hollow portion of the portion 39, a load cell 73 for measuring the loaded load, and a piston rod of the hydraulic jack 69. A displacement meter 75 for measuring the displacement is provided.

Each pallet vertical load load member 65 is installed at a position facing each other with the pressurized vertical load load member 63 interposed therebetween, and applies a load to the pallet load point 39 in the axial direction of the specimen 23.
Each pallet vertical load member 65 has a hydraulic jack 77 whose lower end is swingably attached to the mounting base 61 and one end attached to a piston rod of the hydraulic jack 77, and a hollow portion of the electronic equipment load point 47. The other end of the load load rod 79 is swingably attached to the pallet load point 39, the load cell 81 for measuring the loaded load, and the displacement meter for measuring the displacement of the piston rod of the hydraulic jack 77. 83.

The electronic device vertical load load members 67 are opposed to each other with the pressurized vertical load load member 63 interposed therebetween, and are installed at positions approximately 90 degrees apart from the pallet vertical load load member 65 in the circumferential direction. On the other hand, a load is applied in the axial direction of the specimen 23.
Each electronic device vertical load load member 67 has a hydraulic jack 85 whose lower end is swingably attached to the mounting base 61, one end is attached to a piston rod of the hydraulic jack 85, and the other end is an electronic device load point. 47, a load-loading rod (not shown) that is swingably attached to 47, a load cell (not shown) that measures the applied load, and a displacement meter (not shown) that measures the displacement of the piston rod of the hydraulic jack 85. And are provided.

  Thus, since the axial load load portion 53 has the pallet vertical load load members 65 and the electronic device vertical load load members 67 arranged at intervals of 90 degrees around the pressurized load load member 63, the occupied area Can be reduced.

  The first horizontal load load portion 55 and the second horizontal load load portion 57 are installed at positions approximately 90 degrees apart about the axis center of the specimen 23. Since the first horizontal load load portion 55 and the second horizontal load load portion 57 have substantially the same configuration, the configuration of the first horizontal load load portion 55 will be mainly described below. The members of the first horizontal load load portion 55 are distinguished by adding a suffix “a” to the members, and the members of the second horizontal load load portion 57 are suffixed with “b”.

  The first horizontal load load portion 55 has a lower end fixed to the floor 49, a support column 87a extending in the vertical direction, a pressurized horizontal load load member 89a attached to the support column 87a, and a pallet horizontal load load member. 91a and an electronic equipment horizontal load load member 93a.

The pressurized horizontal load loading member 89a is attached to the upper end portion of the column 87a so as to extend substantially horizontally toward the center of the axis of the specimen 23, and applies a load to the pressurized load point 51 in the horizontal direction. Is.
One end of the pressurized horizontal load load member 89a is attached to the piston rod of the hydraulic jack 95a and one end is attached to the piston rod of the hydraulic jack 95a. A load load rod 97a movably attached, a load cell 99a for measuring the applied load, and a displacement meter 101a for measuring the displacement of the piston rod of the hydraulic jack 95a are provided.

The pressurized horizontal load load member 89a and the pressurized horizontal load load member 89b are arranged so as to be substantially orthogonal to each other.
Thus, since the load applied in the horizontal direction acts on the pressurized load point 51 from two directions, the load in a substantially horizontal plane applied to the pressurized load point 51 is the pressurized horizontal load load member 89a. And the load applied by the pressurized horizontal load load member 89b are combined. Therefore, by controlling the hydraulic jack 95a and the hydraulic jack 95b and controlling the load level of the pressurized horizontal load load member 89a and the pressurized horizontal load load member 89b, a load can be applied in an arbitrary direction within the horizontal plane. .
By applying a load in the axial direction of the specimen 23 by the pressurized vertical load load member 63 to this, a load can be applied to the pressurized load point 51 in any direction in three dimensions.

The pallet horizontal load load member 91a is attached so as to extend substantially horizontally toward the axis center of the specimen 23 at a height position substantially equal to the position of the upper end portion of the pallet load point 39 on the column 87a. A load is applied to the point 39 in the horizontal direction.
The pallet horizontal load load member 91a has a hydraulic jack 103a with one end swingably attached to the column 87a, one end attached to the piston rod of the hydraulic jack 103a, and the other end swingable to the pallet load point 39. A load load rod 105a attached to the load rod 107a, a load cell 107a for measuring the loaded load, and a displacement meter 109a for measuring the displacement of the piston rod of the hydraulic jack 103a are provided.

The pallet horizontal load load member 91a and the pallet horizontal load load member 91b are arranged so as to be substantially orthogonal to each other, and are respectively inserted through the openings 15.
Thus, since the load applied in the horizontal direction acts on the pallet load point 39 from two directions, the pallet load point 39 in any direction in the horizontal plane with respect to the pallet load point 51 as described above. A load can be applied.
By applying a load in the axial direction of the specimen 23 by the pallet vertical load load member 65 to this, a load can be applied to the pallet load point 39 in an arbitrary direction in three dimensions.

The electronic equipment horizontal load load member 93a is attached so as to extend substantially horizontally toward the center of the axis of the specimen 23 at a height position substantially equal to the position of the upper end portion of the electronic equipment load point portion 47 in the column 87a. A load is applied to the electronic equipment load point 47 in the horizontal direction.
The electronic equipment horizontal load load member 93a has one end attached to the piston rod of the hydraulic jack 111a and one end attached to the piston rod of the hydraulic jack 111a. A load load rod 113a that is movably mounted, a load cell 115a that measures the loaded load, and a displacement meter 117a that measures the displacement of the piston rod of the hydraulic jack 111a are provided.

The electronic equipment horizontal load load member 93a and the electronic equipment horizontal load load member 93b are arranged in an acute angle relationship close to 90 degrees around the axis of the specimen 23 as shown in FIG.
Thus, since the load applied in the horizontal direction acts on the electronic equipment load point 47 from two directions, the electronic equipment load point 47 can be arbitrarily set in the horizontal plane with respect to the electronic load point 51 as described above. A load can be applied in the direction.
By applying a load in the axial direction of the specimen 23 by the electronic equipment vertical load loading member 67 to this, it is possible to apply a load to the electronic equipment load point 47 in any direction in three dimensions.

  The control unit 59 includes a pressurized vertical load load member 63, a pallet vertical load load member 65, an electronic equipment vertical load load member 67, a pressurized horizontal load load members 89a and 89b, pallet horizontal load load members 91a and 91b, and an electronic equipment horizontal. The operation of the load applying device 25 is controlled including the load loading operation of the load loading members 93a and 93b.

[About strength evaluation equipment]
Next, a strength evaluation apparatus and a strength evaluation method according to this embodiment will be described.
The strength evaluation apparatus according to the present embodiment mainly determines the buckling state of the panel 17 of the non-pressurized portion 29 in the specimen 23. In other words, in this embodiment, the area | region used as the object of intensity | strength evaluation is the several panel 17 which is connected in the non-pressurizing part 29 and forms the outer wall.

  As shown in FIG. 6, the intensity evaluation apparatus includes a light irradiation unit (light irradiation means) 201 that irradiates light to the evaluation target area of the specimen 23, and an imaging unit (imaging) that acquires an image of the evaluation target area under illumination. Means) 202 and a calculation unit 203 that evaluates the strength of the evaluation target area in the specimen 23 based on the image of the evaluation target area acquired by the imaging unit 202.

  Among the configurations of the intensity evaluation apparatus, the light irradiation unit 201 and the imaging unit 202 are arranged in the specimen 23, but the arrangement of the calculation unit 203 is not particularly limited. For example, the calculation unit 203 may be provided integrally with the load applying device 25 described above, or may be disposed in a monitoring room that monitors a test.

As shown in FIG. 7, the light irradiation unit 201 has a plurality of fluorescent lamps 212 arranged radially on the bottom plate 211 of the pressurizing unit dummy 27.
The imaging unit 202 is installed at a position where the entire evaluation target area of the specimen 23 can be photographed. In the present embodiment, the evaluation target area is a plurality of panels 17 forming a part of the outer wall of the non-pressurized portion 29 of the specimen 23, and thus the entire panel 17 corresponding to these evaluation target areas is photographed. Two cameras 213 are installed from the periphery of the central portion of the non-pressurizing portion 29 toward the panel 17 of the non-pressurizing portion 29 so as to be able to do so.

  The imaging unit 202 acquires an image of the evaluation target region before the load is applied by the load applying device 25 and during the strength test in which the load is applied, and outputs these images to the calculation unit 203.

The calculation unit 203 evaluates the state of the panel in the evaluation target area by processing the image sent from the photographing unit 202. In the present embodiment, specifically, it is determined whether or not each panel 17 corresponding to the evaluation target region is buckled, and the number of the buckled panels is output as a test result.
Specifically, the calculation unit 203 is a computer, and includes a main storage device such as a CPU and a RAM, an auxiliary storage device, and the like. The auxiliary storage device is a computer-readable recording medium, such as a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, or a semiconductor memory. Various programs are stored in the auxiliary storage device, and various processes are realized by the CPU reading and executing the program from the auxiliary storage device to the main storage device.

FIG. 8 is a functional block diagram showing the functions provided in the calculation unit 203 in an expanded manner. As shown in FIG. 8, the calculation unit 203 includes an image creation unit 221, a first graph creation unit 222, a signal conversion unit 223, and an evaluation unit 224.
The image creation unit 221 compares the image of the specimen 23 before applying a load with the image of the specimen 23 during or after the application of a load, and creates a luminance difference image.
The first graph creation unit 222 sequentially scans the pixel of interest in the difference image created by the image creation unit 221 and reads the luminance difference of the pixel of interest, thereby calculating the luminance difference on the horizontal axis and the pixel on the vertical axis. Create the first graph shown.

The signal conversion unit 223 converts the first graph created by the first graph creation unit 222 into a second graph that is a frequency domain graph.
The evaluation unit 224 evaluates the strength of the evaluation target region in the specimen 23 based on the second graph.

  The strength evaluation of the evaluation target area by the calculation unit 203 is performed in parallel with the test by sequentially processing the images sent from the imaging unit 202 while the load test by the load adding device 25 is performed, for example. The image acquired by the imaging unit 202 may be stored in a storage unit (not shown) in the calculation unit 203 while the strength test is being performed, and the storage unit may be stored after the strength test is completed. Intensity evaluation may be performed by processing the image stored in. Thus, the load application to the specimen by the load application device 25 and the strength evaluation by the strength evaluation device may be performed at the same time or may be performed with a time lag.

  Next, the operation of the strength evaluation apparatus according to this embodiment will be described. Here, the case where the image acquired by the imaging unit 202 is accumulated in the storage unit, and after the load addition by the load adding device 25 is finished, the image accumulated in the storage unit is analyzed to evaluate the intensity is described. To do.

First, when load application by the load application device 25 is started, the load distribution applied to the specimen 23 in the control unit 59 is set to a distribution close to the actual machine condition of the launch inertia force load. In order to reproduce this load distribution, the control unit 59 calculates the load condition of the direction and magnitude of the load applied to the pressurized load point 51, the pallet load point 39, and the electronic device load point 47, and calculates The pressurized vertical load member 63, the pallet vertical load member 65, the electronic device vertical load member 67, the pressurized horizontal load members 89a and 89b, the pallet horizontal load members 91a and 91b, and the electronic device The load loading operation of the horizontal load loading members 93a and 93b is set. Thereby, the load is gradually applied based on the distribution set for the specimen 23.
During the load application period by the load application device 25, the image of the evaluation target area of the specimen 23 is acquired continuously or at predetermined time intervals by the camera of the imaging unit 202. Thereby, the behavior of the evaluation target area in the load addition period is stored as image information. For example, the image acquired by the imaging unit 202 is transferred to the calculation unit and stored in a storage unit in the calculation unit.

In this way, when the load application by the load application device 25 is completed, the strength evaluation by the calculation unit 203 is performed.
First, the image creation unit 221 of the calculation unit 203 reads an image before applying a load from the storage unit, and performs predetermined image processing on the image.
For example, as shown in FIGS. 9A and 9B, an image acquired by each camera 213 of the imaging unit 202 is distorted depending on the position of the panel. Therefore, in the image processing here, such a process of correcting the image so that the distortion on the image is eliminated and the panel 17 is displayed as a substantially rectangular shape is performed. Thereby, for example, the images shown in FIGS. 9A and 9B are corrected to the images shown in FIG.

Subsequently, the image creation unit 221 reads an image at a predetermined time during the load application stored in the storage unit, and performs the image processing also on this image.
Subsequently, the image creating unit 221 compares the image before the test after the image processing (hereinafter referred to as “reference image”) and the image at the predetermined time after the image processing (hereinafter referred to as “comparison image”). Then, a luminance difference image is created. At this time, if a positional deviation occurs between the reference image and the comparison image, a positional deviation correction process for correcting the positional deviation may be added. By performing such misalignment correction processing, a difference image can be accurately created.

  Next, the image creation unit 221 performs a process of cutting out the area of each panel 17 from the luminance difference image. This panel cut-out process may be performed automatically by detecting an edge or the like on the image. For example, an image after normal image processing is displayed on a display unit (not shown) or the like. It is also possible to provide an operator to specify the area of each panel 17 in this image, and to cut out each panel based on this input instruction.

When the image creation unit 221 creates the difference image for each panel in this way, the difference image of each panel 17 is output to the first graph creation unit 222.
The first graph creating unit 222 takes out one of the difference images of the plurality of panels 17 created by the image creating unit 221 as a processing target image, sequentially scans the target pixel in the difference image, and the target pixel The first graph is created with the horizontal axis representing the pixel and the vertical axis representing the luminance difference.
For example, as shown in FIG. 11, the pixel of interest is scanned from left to right and from bottom to top. Note that the scanning order is preferably determined based on the directionality of distortion generated in the evaluation target region. The first graph creating unit 222 scans the pixel of interest while acquiring the pixel value at that time, that is, the luminance difference between the images before and after applying the load, and the horizontal axis represents the pixel and the vertical axis represents the pixel. The first graph is created by plotting in the coordinate system in which the luminance difference is indicated.
FIG. 12 shows an example of the first graph. On the horizontal axis, the position of 0 corresponds to the lower left pixel of the difference image, and the maximum value on the horizontal axis corresponds to the upper right pixel of the difference image. The image creation unit 221 creates such a first graph for each panel, and outputs this first graph to the signal conversion unit 223.

The signal conversion unit 223 converts the first graph created by the first graph creation unit 222 into a second graph that is a frequency domain graph. For example, the signal conversion unit 223 regards the waveform represented in the first graph as a waveform in the time domain, and creates a frequency domain graph by performing a fast Fourier transform (FFT) on the signal. FIG. 13 shows an example of the second graph. In the second graph, the horizontal axis represents frequency and the vertical axis represents signal level.
When the signal conversion unit 223 creates the second graph of each panel, the signal conversion unit 223 outputs these to the evaluation unit 224.

  The evaluation unit 224 compares the level of the primary mode in the second graph with the levels of other modes. Specifically, the area of the primary mode and the area of the other mode in the second graph are calculated, and the ratio between the area of the primary mode and the area of the other mode is calculated. And when this ratio exceeds a predetermined threshold value, it determines with this panel having buckled. Then, the number of panels determined to be buckled is output as an evaluation result in association with the time when the comparative image is acquired.

Then, by performing the above processing on the image at each time during the load application stored in the storage unit, the number of buckling panels increases from the start to the end of the load application test. It will be represented as a graph. In addition, if the time from the start of the strength test is known, the magnitude of the load applied to the specimen 23 by the control unit 59 can be known, so the relationship between the load and the number of buckling panels can also be grasped. it can.
FIG. 14 is a diagram showing an example of the relationship between the load applied to the specimen and the number of buckling panels in the strength test.

  As described above, according to the strength evaluation apparatus and the strength evaluation method according to the present embodiment, the strength of the evaluation target region is not evaluated by a sensor such as a strain gauge or a displacement meter, but the behavior of the evaluation target region is used as image information. Since the strength is evaluated by analyzing this image, the strength can be evaluated efficiently with a simple configuration without causing an increase in sensors or the like even when the strength test region is wide.

  In the present embodiment, the luminance difference is detected for each pixel, and the first graph is created in units of pixels. However, the present invention is not limited to this. For example, a pixel region composed of a plurality of pixels is scanned to obtain a pixel. The first graph may be created using the average luminance difference in the region. In this way, the processing load can be reduced by using the pixel region.

17 Panel 23 Specimen 29 Non-pressurization unit 201 Light irradiation unit 202 Imaging unit 203 Calculation unit 212 Fluorescent lamp 213 Camera 221 Image creation unit 222 First graph creation unit 223 Signal conversion unit 224 Evaluation unit

Claims (5)

A strength evaluation apparatus for evaluating the strength of an evaluation target region in the specimen when a load is applied to the specimen,
A light irradiating means for irradiating light to an evaluation target region of the specimen;
An imaging means for acquiring an image of an evaluation target area of the specimen under illumination;
An image creating means for comparing the image of the evaluation target area before applying a load with the image of the evaluation target area after applying a load, and creating a difference image of luminance;
The pixel of interest or the region of interest is scanned on the pixel of interest or the region of interest in the difference image in order, and the luminance difference of the pixel of interest or the region of interest is read respectively. A first graph creating means for creating a first graph showing
Signal converting means for converting the first graph into a second graph which is a frequency domain graph;
An intensity evaluation apparatus comprising: evaluation means for evaluating the intensity of the evaluation target region in the specimen based on the second graph.   The evaluation means determines the degree of distortion of the evaluation target region based on the ratio of the area of the predetermined mode to the area of the other mode in the second graph, and the predetermined mode has a tendency of the distortion of interest. The strength evaluation apparatus according to claim 1, which is determined based on the determination. The specimen has a shape in which panels of a predetermined size are connected in a substantially cylindrical shape,
The imaging means is arranged at least one so as to be able to photograph the entire area corresponding to the evaluation target area among the plurality of panels constituting the specimen.
The first graph creating means creates the first graph for each panel,
The said evaluation means determines whether it buckled in units of panels from the said 2nd graph produced in units of panels, and outputs the number of the said panels determined to have buckled as an evaluation result. Item 3. The strength evaluation apparatus according to Item 2.   The intensity evaluation apparatus according to claim 3, wherein a plurality of the illumination means are arranged radially above or below the specimen. A strength evaluation method for evaluating the strength of an evaluation target region in the specimen when a load is applied to the specimen,
Irradiating the specimen with light and obtaining an image of the specimen under illumination; and
Comparing the image of the specimen before applying the load and the image of the specimen after applying the load, and creating an image of luminance difference,
The pixel of interest or the region of interest is scanned on the pixel of interest or the region of interest in the difference image in order, and the luminance difference of the pixel of interest or the region of interest is read respectively. A first graph creating process for creating a first graph showing
A signal conversion process for converting the first graph into a second graph which is a frequency domain graph;
An intensity evaluation method including an evaluation process for evaluating the intensity of the evaluation target region in the specimen based on the second graph.

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