Material Testing Machine

Abstract

To properly set the exposure of a camera that images a self-luminous display.SOLUTION: A fatigue tester 1 is provided, comprising a self-luminous display 30, and further comprises: an exposure setting unit 411 that sets the exposure of a camera 2 to each of a plurality of exposure values EX included in the exposure adjustment range of the camera 2; a first image acquisition unit 412 that causes the camera 2 to image the display surface of the display 30 and acquires a captured image PM, each time the exposure setting unit 411 sets the exposure of the camera 2; a threshold calculation unit 413 that establishes a threshold TH of binarization processing for each of the captured images PM acquired by the image acquisition unit 412; and an exposure determination unit 414 that determines the exposure value EX corresponding to a captured image PM, of which the threshold TH calculated by the threshold calculation unit 413 is closest to a preset target threshold THA, as the exposure of the camera.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a materials testing machine. [Background technology]

[0002] Conventionally, technologies have been proposed for managing the operating status and test data of materials testing machines using a computer. For example, Patent Document 1 discloses a remote platform that acquires data related to the status of a test device and test data by communicating with the test device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2016-541036 Summary of the Invention [Problem to be solved by the invention]

[0004] The configuration disclosed in Patent Document 1 requires a data communication function for the materials testing machine. In other words, it is not possible to remotely monitor a materials testing machine that does not have a communication function. In order to check the operating status and test data of such a materials testing machine, the user must go to the location where the materials testing machine is installed. It is also possible to capture an image of a display with a camera and transmit the captured image to a monitoring terminal, but when capturing an image of a display with a camera, if the exposure of the camera is not appropriate, it can be difficult to detect the characters displayed on the display from the captured image due to disturbances such as reflections.

[0005] The present invention has been made in view of the above circumstances, and has as its object to properly set the exposure of a camera that captures an image of a self-luminous display device. [Means for solving the problem]

[0006] The material testing machine of this embodiment is a material testing machine equipped with a self-luminous display, and includes: an exposure setting unit that sets the exposure of the camera to each of a plurality of exposure values ​​included in the exposure adjustment range of the camera; a first image acquisition unit that causes the camera to capture an image of the display surface of the display each time the exposure setting unit sets the exposure of the camera and acquires the captured image; a threshold calculation unit that calculates a threshold for binarization processing for each captured image acquired by the first image acquisition unit; and an exposure determination unit that determines, as the exposure of the camera, the exposure value corresponding to the captured image for which the threshold calculated by the threshold calculation unit is closest to a predetermined threshold target value. [Effects of the Invention]

[0007] According to the materials testing machine of this embodiment, the exposure of the camera is set to each of a plurality of exposure values ​​included in the exposure adjustment range, and each time the exposure of the camera is set, the camera is caused to capture an image of the display surface of the display unit to obtain the captured image. Furthermore, a threshold value for binarization processing is calculated for each captured image, and the exposure value corresponding to the captured image whose calculated threshold value is closest to a preset threshold target value is determined as the exposure of the camera. Therefore, by setting the threshold target value to an appropriate value, the exposure value of the camera can be set appropriately. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an example of the configuration of a monitoring system for a fatigue testing machine according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram showing an example of the configuration of a fatigue testing machine. [Figure 3] FIG. 2 is a diagram illustrating an example of the configuration of a display surface of a display device. [Figure 4] FIG. 2 is a diagram illustrating an example of the configuration of a second control device. [Figure 5] 10 is a table showing an example of exposure values, first threshold values, and second threshold values. [Figure 6] 10 is a flowchart showing an example of processing by a second control device. DETAILED DESCRIPTION OF THE INVENTION

[0009] [1. Monitoring system configuration] FIG. 1 is a diagram showing an example of the configuration of a monitoring system 100 according to this embodiment. The monitoring system 100 is a system that monitors a fatigue testing machine 1. Fig. 1 illustrates an example of a configuration in which the monitoring system 100 monitors a fatigue testing machine 1. In this embodiment, a case will be described in which the monitoring system 100 monitors a fatigue testing machine 1, but the number of fatigue testing machines 1 to be monitored is not limited to one. The monitoring system 100 may be configured to monitor two or more fatigue testing machines 1. The fatigue testing machine 1 corresponds to an example of a "material testing machine."

[0010] The fatigue testing machine 1 comprises a testing machine main body 10, a first control device 20, a display device 30, and a second control device 40. The fatigue testing machine 1 performs a fatigue test on a test piece SP by controlling the testing machine main body 10 with the first control device 20. For example, the fatigue testing machine 1 repeatedly applies a tensile stress to the test piece SP. The tensile stress and the number of repetitions are set in advance. The number of repetitions is, for example, 10 2 times ~ 10 8 times.

[0011] The surveillance system 100 includes a camera 2 and a server device 3 .

[0012] In this embodiment, a case will be described in which the monitoring system 100 is provided with one camera 2 for each fatigue testing machine 1 to be monitored, but this is not limiting. The monitoring system 100 only needs to be provided with at least one camera 2 for each fatigue testing machine 1 to be monitored. For example, the monitoring system 100 may be provided with two or more cameras 2 for each fatigue testing machine 1 to be monitored.

[0013] Camera 2 is a digital camera equipped with an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and captures an image of imaging area PA including display 30. Camera 2 may be a digital still camera that captures still images, or a digital video camera that captures moving images. The camera 2 is communicatively connected to the second control device 40. The camera 2 and the second control device 40 are communicatively connected via, for example, a cable conforming to the USB (Universal Serial Bus) standard.

[0014] The network NW1 communicatively connects the second control device 40 and the server device 3 via the network NW2. The second control device 40 is connected to the network NW1, and the network NW1 is connected to the network NW2 via a router or gateway (not shown) or another communication network. The network NW1 is connected to the network NW2, and the server device 3 is connected to the network NW2. The network NW1 is, for example, a local area network (LAN). The network NW1 includes, for example, an Ethernet (registered trademark) cable, a router (not shown), a gateway, etc. The network NW1 may also be a wireless communication line such as Wi-Fi (registered trademark).

[0015] The network NW2 connects the second control device 40 and the server device 3 via the network NW1 so that they can communicate with each other. The network NW2 is, for example, a global network such as the Internet, etc. The network NW2 may also be a WAN (Wide Area Network).

[0016] The server device 3 is a computer with a communication function. The server device 3 performs data communication with the second control device 40. The server device 3 is a so-called database server. The server device 3 includes an image storage unit (not shown). The image storage unit is configured with an HDD (Hard Disk Drive), SSD (Solid State Drive), etc., and stores data in a non-volatile manner. The image storage unit stores the captured image PM captured by the camera 2.

[0017] The server device 3 is placed in, for example, a monitoring room. In the monitoring room, a user monitors the fatigue testing machine 1 by monitoring the screen displayed on the display of the server device 3, for example.

[0018] The server device 3 is capable of communicating with the terminal device 4. The terminal device 4 is a terminal device used by a user of the monitoring system 100. Specifically, the terminal device 4 is a computer with a communication function, such as a smartphone. The terminal device 4 may also be, for example, a personal computer or a tablet computer. The terminal device 4 performs data communication with the server device 3.

[0019] In this embodiment, a case where there is one terminal device 4 will be described, but the present invention is not limited to this. There may be two or more terminal devices 4.

[0020] [2. Configuration of fatigue testing machine] 2 is a diagram showing an example of the configuration of the fatigue testing machine 1. The fatigue testing machine 1 includes a testing machine main body 10, a first control device 20, a display device 30, and a second control device 40. The testing machine main body 10 carries out a fatigue test on the test piece SP in accordance with instructions from the first control device 20. The first control device 20 controls the operation of the testing machine main body 10.

[0021] As shown in FIG. 2, the testing machine main body 10 is configured by forming a load frame on a base 11 with a pair of support columns 12a, 12b and a yoke 13, and by fixing a crosshead 14 to the support columns 12a, 12b.

[0022] A hydraulic actuator 15 is disposed on the base 11, and a lower jig 16a for fixing the lower end of the test piece SP is attached to a piston rod 15a of the hydraulic actuator 15. An upper jig 16b for fixing the upper end of the test piece SP is attached to the crosshead 14 via a load cell 17. Each of the lower jig 16a and the upper jig 16b includes a chuck mechanism for gripping the test piece SP. The load cell 17 detects the test force acting on the test piece SP.

[0023] The hydraulic actuator 15 has a servo valve 18 that controls the direction and amount of pressure oil, causing the piston rod 15a to extend and retract. As a result, a test force is applied to the test piece SP fixed between the upper jig 16b and the lower jig 16a. The stroke of the hydraulic actuator 15, i.e., the displacement of the test piece SP, is detected by a differential transformer 19 attached to the hydraulic actuator 15.

[0024] The testing machine main body 10 is provided with an electric power source and a hydraulic power source (not shown). The electric power source supplies electric power to each part of the testing machine main body 10. The electric power source supplies electric power to, for example, various motors to drive them. The hydraulic power source supplies hydraulic pressure to a hydraulic device constituting the testing machine main body 10. The hydraulic power source supplies hydraulic pressure to, for example, a hydraulic actuator 15 to drive the hydraulic actuator 15. That is, the hydraulic actuator 15 is driven by hydraulic pressure supplied from the hydraulic power source, and the piston rod 15a is extended and retracted. The hydraulic power source includes, for example, a hydraulic pump and a hydraulic control valve, and generates hydraulic pressure by driving the hydraulic pump. The hydraulic control valve adjusts the hydraulic pressure output from the hydraulic power source. Electric power is supplied to the hydraulic pump and the hydraulic control valve from the electric power source.

[0025] The first control device 20 acquires the test force signal FS output from the load cell 17 and performs A / D conversion of the test force signal FS to generate test force information. The first control device 20 acquires the displacement signal DS output from the differential transformer 19 and performs A / D conversion of the displacement signal DS to generate displacement information. The first control device 20 generates command information based on the test force information and the displacement information. The first control device 20 generates a command signal CS by D / A converting the command information and outputs the generated command signal CS to the servo valve 18. The servo valve 18 controls the direction and amount of pressure oil to be supplied to the hydraulic actuator 15 in accordance with a command signal CS output from the first control device 20.

[0026] The first control device 20 is communicably connected to the display device 30. The display device 30 is a self-luminous display device. The display device 30 is configured, for example, with an LED (Light Emitting Diode) or the like. The first control device 20 displays, for example, the number of repetitions acquired from the testing machine main body 10 on the display device 30. Display 30 is further described with reference to FIG.

[0027] In FIG. 2, amplifiers for amplifying each of the test force signal FS, the displacement signal DS, and the command signal CS may be disposed between the testing machine main body 10 and the first control device 20.

[0028] The camera 2 captures an image of the imaging area PA including the display 30. The camera 2 is communicably connected to the second control device 40. The camera 2 sets exposure according to instructions from the second control device 40. The camera 2 also captures an image of the imaging area PA according to instructions from the second control device 40, and generates a captured image PM. The camera 2 outputs the generated captured image PM to the second control device 40. The second control device 40 will be further described with reference to FIG.

[0029] In this embodiment, the first control device 20 is described as a device having a housing on which a display and various keys are arranged, but is not limited to this. The first control device 20 may be configured as, for example, a personal computer. In this case, the display is a display connected to the personal computer or a display provided in the personal computer.

[0030] [3. Display configuration] 3 is a diagram showing an example of the configuration of the display surface of the display device 3. The display device 3 includes a first display device 31 and a second display device 32. The first display 31 is configured with a 7-segment LED that emits light in a first color. In this embodiment, the first color is red. The first display 31 is configured with, for example, five 7-segment LEDs. The second display 32 is configured with a 7-segment LED that emits light in a second color different from the first color. In this embodiment, the first color is green. The second display 32 is configured with, for example, seven 7-segment LEDs.

[0031] The first display 31 displays, for example, the actual value of the number of repetitions in accordance with an instruction from the first control device 20. The actual value of the number of repetitions indicates the number of times that the fatigue testing machine 1 has applied tensile stress to the test piece SP. The second display 32 displays, for example, the maximum number of repetitions in accordance with instructions from the first control device 20. The maximum number of repetitions indicates the number of repetitions at which the fatigue test ends. In other words, when the actual number of repetitions reaches the maximum number of repetitions, the fatigue testing machine 1 ends the fatigue test.

[0032] [4. Configuration of the second control device] FIG. 4 is a diagram showing an example of the configuration of the second control device 40. As shown in FIG. The second control device 40 includes a processor 41 , a memory 42 , and a communication interface 43 .

[0033] The second control device 40 is configured, for example, by a personal computer. The second control device 40 may be configured by one or more appropriate circuits such as an IC chip, an integrated circuit such as an LSI, etc. The second control device 40 may also be configured, for example, by a tablet terminal, a smartphone, etc.

[0034] The processor 41 is configured with a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), etc. The memory 42 is configured with a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD, an SSD, etc. The memory 42 stores a control program 421.

[0035] The communication interface 43 is connected to the network NW1 and communicates with the server device 3 via the networks NW1 and NW2. The communication interface 43 includes, for example, a connector to which a communication cable can be connected and a communication circuit. The communication interface 43 may also include a wireless communication interface and be configured to perform wireless communication.

[0036] The second control device 40 includes an exposure setting unit 411, a first image acquisition unit 412, a threshold calculation unit 413, an exposure determination unit 414, a second image acquisition unit 415, a character recognition unit 416, a communication control unit 417, and an image memory unit 422. Specifically, the processor 41 of the server device 3 executes a control program 421 stored in the memory 42, thereby functioning as an exposure setting unit 411, a first image acquisition unit 412, a threshold calculation unit 413, an exposure determination unit 414, a second image acquisition unit 415, a character recognition unit 416, and a communication control unit 417. In addition, the processor 41 executes the control program 421, thereby causing the memory 42 to function as an image storage unit 422.

[0037] The image storage section 422 stores the captured image PM acquired by the first image acquisition section 412. The captured image PM is stored in the image storage section 422 by the first image acquisition section 412. The image storage unit 422 also stores a table TB that associates the exposure value EX with the first threshold value TH1 and the second threshold value TH2. The table TB is stored in the image storage unit 422 by the threshold value calculation unit 413. Table TB will be further described with reference to FIG.

[0038] The exposure setting unit 411 sets the exposure of the camera 2 to an exposure corresponding to each of a plurality of exposure values ​​EX included in the exposure adjustment range of the camera 2. In this embodiment, the exposure adjustment range of the camera 2 is, for example, 17 integers for the exposure value EX from "-8" to "8". Furthermore, in this embodiment, the exposure setting unit 411 sets each of the settable exposure values ​​EX included in the exposure adjustment range of the camera 2. In other words, the exposure setting unit 411 sets the exposure of the camera 2 to an exposure value EX corresponding to each of the 17 integers from "-8" to "8".

[0039] Each time the exposure setting unit 411 sets the exposure of the camera 2, the first image acquisition unit 412 causes the camera 2 to capture an image of the display surface of the display 30 and acquires the captured image PM. In this embodiment, the first image acquisition section 412 acquires captured images PM whose exposure values ​​EX correspond to 17 integers from "-8" to "8".

[0040] The threshold calculation unit 413 calculates a threshold value TH for binarization processing for each of the captured images PM acquired by the first image acquisition unit 412. The threshold calculation unit 413, for example, performs "Otsu's binarization processing" on each of the captured images PM acquired by the first image acquisition unit 412 to calculate the threshold value TH. In "Otsu's binarization process", a threshold value TH that maximizes the degree of separation is determined. The threshold values ​​TH include a first threshold value TH1 and a second threshold value TH2.

[0041] The first threshold value TH1 is the threshold value TH of the first captured image PM1, which is the captured image of the first display 31, among the captured images PM. In other words, the threshold value calculation unit 413 performs "Otsu's binarization process" on the first captured image PM1, among the captured images PM acquired by the first image acquisition unit 412, to obtain the first threshold value TH1. The second threshold value TH2 is the threshold value TH of the second captured image PM2, which is the captured image of the second display 32, among the captured images PM. In other words, the threshold value calculation unit 413 performs "Otsu's binarization process" on the second captured image PM2, among the captured images PM acquired by the first image acquisition unit 412, to obtain the second threshold value TH2.

[0042] The threshold calculation unit 413 generates a table TB by associating an exposure value EX indicating the exposure of the camera 2 when the captured image PM was captured with a first threshold value TH1 corresponding to the first captured image PM1 and a second threshold value TH2 corresponding to the second captured image PM2. The threshold calculation unit 413 then stores the table TB in the image storage unit 422. Table TB will be described with reference to FIG.

[0043] The exposure determination unit 414 determines the exposure value EX corresponding to the captured image PM in which the threshold value TH calculated by the threshold calculation unit 413 is closest to a preset threshold target value THA as the exposure of the camera 2. The threshold value TH includes a first threshold value TH1 and a second threshold value TH2.

[0044] That is, the exposure determination unit 414 determines the first exposure value EX1 as the exposure of the camera 2 when capturing an image of the first display 31. The first exposure value EX1 is the exposure value EX when the first captured image PM1 is captured, at which the first threshold value TH1 calculated by the threshold calculation unit 413 is closest to the threshold target value THA. Furthermore, the exposure determination unit 414 determines the second exposure value EX2 as the exposure of the camera 2 when capturing an image of the second display 32. The second exposure value EX2 is the exposure value EX when the second captured image PM2 is captured, at which the second threshold value TH2 calculated by the threshold calculation unit 413 is closest to the threshold target value THA. When the luminance of the captured image PM is expressed, for example, in 256 gradations, the threshold target value THA is set, for example, to "40." The threshold target value THA is set so as to maximize the accuracy of character recognition of the captured image PM.

[0045] The second image acquisition unit 415 sets the exposure of the camera 2 to the exposure value EX determined by the exposure determination unit 414, and causes the camera 2 to capture an image of the display surface of the display device 3, thereby acquiring the captured image PM. The second image acquisition unit 415 sets the exposure of the camera 2 to the first exposure value EX1, causes the camera 2 to capture an image of the display surface of the first display 31, and acquires a first captured image PM1. The second image acquisition unit 415 also sets the exposure of the camera 2 to the second exposure value EX2, causes the camera 2 to capture an image of the display surface of the second display 32, and acquires a second captured image PM2.

[0046] The character recognition unit 416 performs character recognition processing on the captured image PM acquired by the second image acquisition unit 415, and acquires the characters displayed on the display 3. The character recognition unit 416 performs character recognition processing on the first captured image PM1 acquired by the second image acquisition unit 415, and acquires the characters displayed on the first display 31. In addition, the character recognition unit 416 performs character recognition processing on the second captured image PM2 acquired by the second image acquisition unit 415, and acquires the characters displayed on the second display 32.

[0047] The communication control unit 417 controls communication with the camera 2. The communication control unit 417 also controls communication with the server device 3 via the communication interface 43 through the networks NW1 and NW2.

[0048] [5. Relationship between exposure value and first and second thresholds] Next, the relationship between the exposure value EX and the first and second threshold values ​​TH1 and TH2 will be described with reference to Fig. 5. Fig. 5 is a table showing an example of the exposure value EX, the first and second threshold values ​​TH1 and TH2. As shown in Fig. 5, the exposure setting unit 411 sets the exposure value EX to one of 17 integers ranging from "-8" to "8." The larger the value of the exposure value EX, the greater the exposure. In other words, the larger the value of the exposure value EX, the greater the brightness of the captured image PM. The brightness of the captured image PM is expressed, for example, in 256 gradations.

[0049] The first threshold value TH1 is a threshold value TH of the first captured image PM1, which is an image captured by the first display 31, among the captured images PM. The second threshold value TH2 is a threshold value TH of the second captured image PM2, which is an image captured by the second display 32, among the captured images PM. The first threshold value TH1 and the second threshold value TH2 are calculated by the threshold value calculation unit 413.

[0050] 5, the first threshold TH1 and the second threshold TH2 each increase as the exposure value EX increases. Furthermore, when the exposure value EX is smaller than "2," the second threshold TH2 is smaller than the first threshold TH1. When the exposure value EX is larger than "2," the second threshold TH2 is larger than the first threshold TH1. In other words, the second threshold TH2 is more susceptible to changes in the exposure value EX than the first threshold TH1.

[0051] Since the threshold target value THA is "40", the exposure determination section 414 determines the first exposure value EX1 to be "-4" and the second exposure value EX2 to be "-3".

[0052] [6. Processing of the second control device] Next, the processing of the second control device 40 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of the processing of the second control device 40. 6, first, in step S101, the exposure setting unit 411 sets the exposure of the camera 2 to an exposure corresponding to each of a plurality of exposure values ​​EX included in the exposure adjustment range of the camera 2. The exposure setting unit 411 sequentially sets the exposure of the camera 2 to an exposure corresponding to each of 17 integers from "-8" to "8", for example, as the exposure value EX. Next, in step S103, the first image acquisition unit 412 causes the camera 2 to capture an image of the display surface of the display 30 each time the exposure setting unit 411 sets the exposure of the camera 2, and acquires a captured image PM. Next, in step S105, the threshold calculation unit 413 calculates a threshold value TH for binarization processing for each of the captured images PM acquired by the first image acquisition unit 412. The threshold calculation unit 413, for example, performs "Otsu's binarization processing" on each of the captured images PM acquired by the first image acquisition unit 412 to calculate the threshold value TH.

[0053] Next, in step S107, the exposure setting unit 411 determines whether or not all of the settable exposure values ​​EX that are included in the exposure adjustment range of the camera 2 have been set. If the exposure setting unit 411 determines that not all of the settable exposure values ​​EX have been set (step S107; NO), the process returns to step S101. If the exposure setting unit 411 determines that all of the settable exposure values ​​EX have been set (step S107; YES), the process proceeds to step S109. Then, in step S109, the exposure determination unit 414 determines the exposure value EX corresponding to the captured image PM for which the threshold value TH calculated by the threshold calculation unit 413 is closest to the preset threshold target value THA as the exposure of the camera 2. For convenience, in Fig. 6, the exposure value EX corresponding to the captured image PM closest to the threshold target value THA is described as the "optimal exposure value."

[0054] Next, in step S111, second image acquisition unit 415 sets the exposure of camera 2 to exposure value EX determined in step S109, causes camera 2 to capture an image of the display surface of display 3, and acquires captured image PM. Next, in step S115, the character recognition unit 416 performs character recognition processing on the captured image PM acquired in step S111, and acquires the characters displayed on the display 3. Next, in step S117, the second control device 40 determines whether or not to end the imaging of the display device 30. For example, the second control device 40 receives an operation from the user and determines whether or not to end the imaging of the display device 30 based on the received operation. If the second control device 40 determines not to end the imaging of the display device 30 (step S117; NO), the process returns to step S101. If the second control device 40 determines to end the imaging of the display device 30 (step S117; YES), the process then ends.

[0055] [7. Aspects and Effects] It will be understood by those skilled in the art that the above-described embodiment is a specific example of the following aspects.

[0056] (Section 1) The material testing machine of this embodiment is a material testing machine equipped with a self-luminous display, and includes: an exposure setting unit that sets the exposure of the camera to each of a plurality of exposure values ​​included in the exposure adjustment range of the camera; a first image acquisition unit that causes the camera to capture an image of the display surface of the display each time the exposure setting unit sets the exposure of the camera and acquires the captured image; a threshold calculation unit that calculates a threshold for binarization processing for each captured image acquired by the first image acquisition unit; and an exposure determination unit that determines, as the exposure of the camera, the exposure value corresponding to the captured image for which the threshold calculated by the threshold calculation unit is closest to a predetermined threshold target value.

[0057] According to the materials testing machine described in paragraph 1, the exposure of the camera is set to each of a plurality of exposure values ​​included in the adjustment range of the exposure of the camera, and each time the exposure of the camera is set, the camera is caused to capture an image of the display surface of the display device to obtain the captured image. Then, a threshold value for binarization processing is calculated for each of the captured images, and the exposure value corresponding to the captured image whose threshold value is closest to a preset threshold target value is determined as the exposure of the camera. Therefore, by setting the threshold target value to an appropriate value, the exposure of the camera can be determined appropriately.

[0058] (Section 2) In the material testing machine described in paragraph 1, the threshold calculation unit performs Otsu's binarization process on each of the captured images acquired by the first image acquisition unit to find the threshold.

[0059] According to the material testing machine described in paragraph 2, Otsu's binarization process is performed on each of the acquired captured images to determine the threshold value. Therefore, it is possible to determine an appropriate threshold value, in other words, a threshold value that maximizes the degree of separation.

[0060] (Section 3) In the material testing machine described in paragraph 1 or 2, the exposure setting unit is set to each of the settable exposure values ​​included in the exposure adjustment range of the camera.

[0061] According to the material testing machine described in paragraph 3, the exposure is set to each of the settable exposure values ​​that are included in the exposure adjustment range of the camera. Therefore, the exposure of the camera can be appropriately determined from among the settable exposure values.

[0062] (Section 4) In the material testing machine described in any one of paragraphs 1 to 3, the display comprises a first display that emits light in a first color and a second display that emits light in a second color different from the first color, the threshold calculation unit calculates a first threshold for the first display and a second threshold for the second display, and the exposure determination unit determines an exposure value corresponding to an image in which the first threshold is closest to the threshold target value as the exposure of the camera when capturing an image of the first display, and determines an exposure value corresponding to an image in which the second threshold is closest to the threshold target value as the exposure of the camera when capturing an image of the second display.

[0063] According to the material testing machine described in paragraph 4, the exposure of the camera when capturing an image of a first indicator emitting light in a first color is determined to be an exposure value corresponding to a captured image in which the first threshold is closest to the threshold target value. Also, the exposure of the camera when capturing an image of a second indicator emitting light in a second color different from the first color is determined to be an exposure value corresponding to a captured image in which the second threshold is closest to the threshold target value. Therefore, the exposure of the camera when capturing an image of the first display device and the exposure of the camera when capturing an image of the second display device can be determined appropriately.

[0064] (Section 5) The material testing machine described in any one of paragraphs 1 to 4 includes a second image acquisition unit that sets the exposure of the camera to the exposure value determined by the exposure determination unit, causes the camera to capture an image of the display surface of the display device, and acquires the captured image, and a character recognition unit that performs character recognition processing on the captured image acquired by the second image acquisition unit, and acquires the characters displayed on the display device.

[0065] According to the material testing machine described in paragraph 5, the exposure of the camera is set to the exposure value determined by the exposure determination unit, and the camera is caused to capture an image of the display surface of the display device, and then character recognition processing is performed on the captured image to obtain the characters displayed on the display device. Therefore, the characters displayed on the display can be properly acquired.

[0066] 8. Other Embodiments The fatigue testing machine 1 according to this embodiment is merely an example of an embodiment of a material testing machine according to the present invention, and can be modified and applied as desired within the scope of the present invention.

[0067] For example, in this embodiment, a case will be described in which the material testing machine is a fatigue testing machine 1, but the present invention is not limited to this. The material testing machine may be, for example, a tensile testing machine, a compression testing machine, a bending testing machine, a torsion testing machine, or the like.

[0068] Furthermore, in this embodiment, a case will be described in which the exposure setting unit 411 sets each of the settable exposure values ​​EX included in the exposure adjustment range of the camera 2, but the present invention is not limited to this. The exposure setting unit 411 may set the exposure corresponding to each of the multiple exposure values ​​EX included in the exposure adjustment range of the camera 2. For example, the exposure setting unit 411 may set the exposure corresponding to each of the nine exposure values ​​EX from "-8" to "0." The fewer the number of exposure values ​​EX set by the exposure setting unit 411, the simpler the processing. The more exposure values ​​EX set by the exposure setting unit 411, the more appropriate the exposure determination unit 414 can determine the exposure value EX.

[0069] Furthermore, in the present embodiment, a case will be described in which the character recognition unit 416 performs character recognition processing on the captured image PM acquired by the second image acquisition unit 415 to acquire characters displayed on the display 3, but this is not limiting. The character recognition unit 416 may also acquire characters displayed on the display 3 by machine learning such as deep learning. For example, the trained model is stored in advance in the memory 42 of the second control device 40. The trained model is obtained by training a data set, in which the captured image PM is used as input and the characters displayed on the display device 3 are used as output, through machine learning (so-called "supervised learning"). In this case, the character recognition unit 416 inputs the captured image PM acquired by the second image acquisition unit 415 into the trained model, thereby acquiring the characters displayed on the display device 3 as the output of the trained model.

[0070] In addition, in this embodiment, a case where the display 3 includes a first display 31 that emits light in a first color and a second display 32 that emits light in a second color different from the first color will be described, but this is not limiting. For example, the display 3 may include multiple display devices that emit light in the first color. Also, for example, the display 3 may include three or more display devices that emit light in different colors.

[0071] 4 indicates a functional configuration, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware corresponding to each functional unit individually, and it is of course possible to implement a configuration in which a single processor executes a program to realize the functions of multiple functional units. Furthermore, some of the functions realized by software in the above embodiments may be realized by hardware, or some of the functions realized by hardware may be realized by software.

[0072] 6 is divided according to the main processing content to facilitate understanding of the processing by the second control device 40. There is no limitation to the manner in which the processing units are divided or the names thereof shown in the flowchart of FIG. 6, and the processing units can be divided into more processing units according to the processing content, or one processing unit can be divided to include more processes. Furthermore, the processing order of the above flowchart is not limited to the example shown in the figure.

[0073] The control program 421 that the second control device 40 causes the processor 41 to execute can also be recorded on a computer-readable recording medium. The recording medium may be a magnetic or optical recording medium or a semiconductor memory device, specifically, a portable or fixed recording medium such as a flexible disk, HDD, CD-ROM (Compact Disk Read Only Memory), DVD, Blu-ray (registered trademark) Disc, magneto-optical disk, flash memory, or card-type recording medium. The recording medium may be a non-volatile storage device such as a RAM, a ROM, or a HDD that is an internal storage device provided in the second control device 40. The control program 421 may be stored in a server device or the like, and the control program 421 may be downloaded from the server device to the second control device 40. [Explanation of symbols]

[0074] 1. Fatigue testing machine (material testing machine) 10 Testing machine body 20 First control device 30 Display 31 1st display 32 2nd display 40 Second control device 41 processors 411 Exposure setting section 412 First image acquisition unit 413 Threshold calculation unit 414 Exposure determining section 415 Second Image Acquisition Unit 416 Character recognition section 417 Communication Control Unit 42 memory 421 Control Program 422 Image storage unit 2 Cameras 3. Server equipment 4 Terminal Devices EX Exposure Value EX1 First exposure value EX2 Second exposure value PA imaging area PM captured image PM1 1st captured image PM2 2nd image TB Table TH threshold TH1 First threshold TH2 Second threshold THA threshold target value

Claims

1. A material testing machine equipped with a self-luminous display, an exposure setting unit that sets the exposure of the camera to each of a plurality of exposure values ​​included in an exposure adjustment range of the camera; a first image acquisition unit that causes the camera to capture an image of the display surface of the display device and acquires the captured image each time the exposure setting unit sets the exposure of the camera; a threshold calculation unit that calculates a threshold for binarization processing for each of the captured images acquired by the first image acquisition unit; an exposure determination unit that determines, as the exposure of the camera, an exposure value corresponding to a captured image in which the threshold calculated by the threshold calculation unit is closest to a preset threshold target value; A material testing machine comprising:

2. the threshold calculation unit performs Otsu's binarization processing on each of the captured images acquired by the first image acquisition unit to obtain the threshold.

2. The material testing machine according to claim 1.

3. the exposure setting unit sets each of the settable exposure values ​​included in the exposure adjustment range of the camera; 3. A material testing machine according to claim 1 or 2.

4. the indicator comprises a first indicator that emits light in a first color and a second indicator that emits light in a second color different from the first color; the threshold calculation unit calculates a first threshold for the first display device and a second threshold for the second display device; the exposure determination unit determines an exposure value corresponding to a captured image in which the first threshold is closest to the threshold target value as the exposure of the camera when capturing an image of the first display device, and determines an exposure value corresponding to a captured image in which the second threshold is closest to the threshold target value as the exposure of the camera when capturing an image of the second display device. The material testing machine according to any one of claims 1 to 3.

5. a second image acquisition unit that sets the exposure of the camera to the exposure value determined by the exposure determination unit, causes the camera to capture an image of the display surface of the display device, and acquires the captured image; a character recognition unit that performs character recognition processing on the captured image acquired by the second image acquisition unit and acquires characters displayed on the display; The material testing machine according to any one of claims 1 to 4, comprising:

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