Elastic-body coupler, ultrasonic data acquisition device, and ultrasonic data acquisition method

Abstract

The present invention provides an elastic-body coupler to be interposed between a sensor unit capable of transmitting and receiving ultrasonic waves and an object of observation, the elastic-body coupler including: an elastic body for propagating ultrasonic waves between the sensor unit and the object of observation; and a pseudo-target embedded in the elastic body and capable of reflecting a portion of the ultrasonic waves.

Description

Elastic coupler, ultrasonic data acquisition device, and ultrasonic data acquisition method

[0001] The present invention relates to an elastic coupler, an ultrasonic data acquisition device, and an ultrasonic data acquisition method.

[0002] In developed countries, the labor force is shrinking due to an aging population, and as a result of the promotion of DX (Digital Transformation) to solve this problem, automation of manufacturing is progressing. For example, sensors are installed on factory production lines to monitor pipes, their internal condition, and foreign objects within the pipes. This allows for early detection of blockages and foreign objects in the pipes, improving product quality and preventing accidents.

[0003] Furthermore, the introduction of MI / PI (Material and Process Informatics) is progressing, which optimizes material specifications and process parameters by analyzing trends in data acquired during the manufacturing process. To maximize its effectiveness, there is a need for a means to acquire a wider variety of data and multivariate data over a long period of time than ever before.

[0004] Data acquisition in manufacturing lines is preferably non-destructive. For example, ultrasound-based devices are promising for acquiring multivariate data during processes because they are small, inexpensive, and safe for anyone to use.

[0005] Since ultrasonic waves have the property of easily propagating in water, it is known that water, gel, or the like is used as a matching material between a sensor and an object. For example, Patent Document 1 discloses a configuration in which a test object is submerged in water to detect defects within the test object. Furthermore, Patent Document 2 discloses a configuration in which a phantom in which a target is placed in gel, urethane rubber, or the like is attached to an ultrasonic probe to perform maintenance on an ultrasonic diagnostic device.

[0006] However, a configuration in which the object is immersed in water, as in the configuration described in Patent Document 1, requires large-scale equipment and limits the objects that can be inspected. Also, the gel used in the configuration described in Patent Document 2 dries quickly, so it is necessary to periodically check the contact state with the ultrasound probe and to reapply the gel.

[0007] As an alternative to water and gel, a method using an elastic coupler made of a polymeric material or the like is known (see, for example, Patent Document 3). Elastic couplers have a stable shape, making them easy to handle and advantageous for acquiring data over a long period of time. Therefore, for example, by placing an elastic coupler between a target object such as a pipe and a probe, ultrasonic waves can be efficiently transmitted to the target object, and data on foreign objects in the pipe can be acquired over a long period of time.

[0008] JP 2017-161230 A JP 2017-143973 A JP 2020-183929 A

[0009] However, the elastic coupler may also suffer from drying or deterioration. This can lead to a decrease in ultrasonic characteristics (e.g., transmittance) or changes in the contact conditions between the elastic coupler and the probe and target object. Therefore, if the elastic coupler dries or deteriorates during data acquisition, proper data acquisition may become impossible, and the reliability of the acquired data may be compromised.

[0010] Because the occurrence of the above problems varies depending on the conditions and environment of the production line, it is difficult to grasp the changes and trends in the condition of the elastic coupler based solely on the material of the elastic coupler. Also, when data fluctuations occur due to deterioration of the ultrasonic sensor element, it is impossible to distinguish between this and the above problems.

[0011] An object of the present invention is to provide an elastic coupler, an ultrasonic data acquisition device, and an ultrasonic data acquisition method that are capable of isolating the cause of data fluctuations while ensuring the reliability of acquired data.

[0012] The elastic coupler of the present invention is an elastic coupler interposed between a sensor unit capable of transmitting and receiving ultrasonic waves and an object to be observed, and includes an elastic body that propagates ultrasonic waves between the sensor unit and the object to be observed, and a pseudo target that is contained within the elastic body and can reflect a portion of the ultrasonic waves.

[0013] The ultrasonic data acquisition device according to the present invention comprises a sensor unit including a transmitting unit that transmits ultrasonic waves and a receiving unit that receives ultrasonic components reflected from a reflecting object and acquires ultrasonic data that can be used to construct an ultrasonic tomographic image; and an elastic body coupler interposed between the sensor unit and the object to be observed, the elastic body having an elastic body that propagates ultrasonic waves between the sensor unit and the object to be observed, and a pseudo target that is contained in the elastic body and can reflect part of the ultrasonic waves.

[0014] The ultrasonic data acquisition method according to the present invention is a method for acquiring ultrasonic data using an elastic coupler interposed between the sensor unit and the object of observation, which has an elastic body that propagates ultrasonic waves between the sensor unit and the object of observation, and a pseudo target that is contained in the elastic body and can reflect a portion of the ultrasonic waves, and includes the steps of: transmitting the ultrasonic waves from the sensor unit; and receiving ultrasonic components reflected from a predetermined detection target and the pseudo target within the object of observation, to acquire ultrasonic data that can be used to construct an ultrasonic tomographic image.

[0015] According to the present invention, it is possible to isolate the cause of data fluctuations while ensuring the reliability of acquired data.

[0016] 10 is a flowchart showing an example of an operation of evaluation processing of ultrasonic data by a control unit. FIG. 11 is an enlarged view of an elastic coupler portion according to a modified example. FIG. 12 is an enlarged view of an elastic coupler portion according to a modified example. FIG. 13 is a diagram showing a change in the characteristics of mass change of an elastic coupler due to a drying experiment of the elastic coupler. FIG. 14 is a diagram showing a reflection intensity characteristic at a first time in a drying experiment. FIG. 15 is a diagram showing a reflection intensity characteristic at a second time in a drying experiment. FIG. 16 is a flowchart showing an example of an operation of evaluation processing of ultrasonic data by a control unit. FIG. 17 is an enlarged view of an elastic coupler portion according to a modified example. FIG. 18 is a diagram showing an example of an ultrasonic tomographic image in the configuration shown in FIG. 7. FIG. 19 is a flowchart showing an example of an operation of evaluation processing of ultrasonic data by a control unit of the modified example shown in FIG. 1 FIG. 10 is an enlarged view of an elastic coupler portion according to a modified example.

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to the accompanying drawings. Fig. 1 is a diagram schematically illustrating an example of the configuration of an evaluation device 1 according to an embodiment of the present invention. The evaluation device 1 corresponds to the "ultrasound data acquisition device" of the present invention.

[0018] 1, the evaluation device 1 is an ultrasonic flaw detection device that can acquire ultrasonic data and non-destructively detects a detection target D inside an observation target O. Specifically, the evaluation device 1 transmits ultrasonic waves and receives ultrasonic waves that have returned via the observation target O. The evaluation device 1 performs an evaluation to detect the detection target D present inside the observation target O based on the acquired ultrasonic data (received ultrasonic waves).

[0019] The observation target O is an object whose interior is uniformly configured and whose interior cannot be observed visually from the outside, and may be, for example, a pipe installed on a production line in a factory.

[0020] The detection target D is a foreign object present inside the observation target O, and is an object to be detected by the evaluation device 1. For example, if the observation target O is a pipe, a solvent containing dissolved raw materials for a manufactured product (e.g., a film material used in a liquid crystal panel) flows inside the pipe. During this process, metal, resin, semi-solid polymeric material, rubber fragments, etc. may become mixed into the solvent inside the pipe due to deterioration of the pipe, the structure of the operating mechanism of the on-off valve, etc. In other words, in this case, the foreign object may be metal, resin, semi-solid polymeric material, rubber fragments, etc.

[0021] The evaluation device 1 includes a control unit 10 , a sensor unit 20 , an elastic coupler 30 , an evaluation unit 40 , and an execution unit 50 .

[0022] The control unit 10 is, for example, a device including a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), etc., such as a computer.

[0023] The control unit 10, for example, controls the sensor unit 20, evaluation unit 40, execution unit 50, etc. by having the CPU refer to the control program and various data stored in the ROM and RAM and execute the control program, thereby realizing each function.

[0024] Some or all of these functions may be realized by an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), a PLD (Programmable Logic Device), a dedicated hardware circuit, etc. Examples of PLDs include FPGAs (Field Programmable Gate Arrays). Some or all of these functions may be configured to be executed by a GPU (Graphics Processing Unit).

[0025] The sensor unit 20 is a probe capable of transmitting and receiving ultrasonic waves, and includes a piezoelectric element. The sensor unit 20 has a transmitter 21 and a receiver 22.

[0026] The transmitter 21 transmits ultrasonic waves toward the observation target O. The transmitter 21 may also be capable of adjusting the transmission level (transmission intensity) of the ultrasonic waves.

[0027] The receiving unit 22 receives ultrasonic waves reflected from the observation target O and converts them into a received signal. That is, the receiving unit 22 receives ultrasonic components reflected from a predetermined detection target D within the observation target O and a pseudo target 32 ​​(described later) to obtain ultrasonic data from which an ultrasonic tomographic image can be constructed.

[0028] The elastic body coupler 30 is interposed between the sensor unit 20 and the observation target O, and may be attached to the sensor unit 20 or may be separate from the sensor unit 20. The elastic body coupler 30 has an elastic body 31 and a pseudo target 32. Figure 2 is an enlarged view of the elastic body coupler 30 portion.

[0029] 2 and other drawings, a Cartesian coordinate system (X, Y, Z) is used, and this same Cartesian coordinate system (X, Y, Z) is also used in the drawings described below. In the Cartesian coordinate system, the X direction indicates the left-right direction (the width direction of the sensor unit 20), the Y direction indicates the up-down direction, and the Z direction indicates the direction from the back side to the front side of FIG. 2 and other drawings. When the observation target O is a pipe, the Z direction is the direction in which the observation target O extends.

[0030] The elastic body 31 propagates ultrasonic waves between the sensor unit 20 and the observation target O, and is made of, for example, a polymer-based material. As shown in Fig. 2, the size of the elastic body 31 in the X direction is configured to be equal to or larger than the size of the probe portion 20A of the sensor unit 20 in the width direction (X direction). In this embodiment, the size of the elastic body 31 in the X direction is configured to be larger than the size of the probe portion 20A in the X direction. Furthermore, the size of the elastic body 31 in the Z direction is configured to be equal to or larger than the size of the probe portion 20A in the Z direction.

[0031] The contact surface 31A of the elastic body 31 with the probe portion 20A of the sensor unit 20 is configured as a flat surface along the transmitting / receiving side surface of the probe portion 20A. The contact surface 31B of the elastic body 31 with the observation target O is configured so as to be able to fit onto the surface of the observation target O. For example, in Fig. 2, the contact surface 31B of the elastic body 31 has a curved shape that follows the surface shape of the piping that is the observation target O. Both contact surfaces 31A and 31B are configured as smooth surfaces so as to prevent unintended scattering or refraction of ultrasonic waves.

[0032] When the observation target O is a pipe, the observation target O has a cylindrical shape, and therefore the contact surface 31B is formed to fit into the cylindrical shape. The position of the contact surface 31B in the width direction is set, for example, to a position such that the position of the observation target O is the center in the X direction of the probe portion 20A of the sensor unit 20.

[0033] Furthermore, the elastic body 31 is disposed so as to cover the observation target O. Specifically, the elastic body 31 has a first portion 31C and a second portion 31D. The first portion 31C is located on the sensor unit 20 side with respect to a center line C passing through the center of the observation target O, and is a portion that comes into contact with a surface of the observation target O that is irradiated with ultrasound. The second portion 31D is located on the opposite side of the center line C from the sensor unit 20, and is a portion that comes into contact with a surface of the observation target O that is not irradiated with ultrasound.

[0034] The first portion 31C and the second portion 31D may be configured as an integral body or as separate bodies. When the first portion 31C and the second portion 31D are configured as an integral body, for example, the elastic body 31 has a hole of a size corresponding to the cross section of the observation target O, and the elastic body 31 is installed by fitting the observation target O into the hole.

[0035] Furthermore, when the first part 31C and the second part 31D are configured as separate bodies, the first part 31C is placed on the sensor unit 20 side of the observation target O, and the second part 31D is placed on the opposite side of the observation target O from the sensor unit 20. Then, the first part 31C and the second part 31D are adhered together.

[0036] As shown in FIG. 3, the elastic body 31 may be formed of only the first portion 31C.

[0037] Furthermore, the outer surfaces of the elastic body 31 (the side and bottom surfaces of the elastic body 31 in FIGS. 2 and 3 ) other than the contact surfaces 31A and 31B with the sensor unit 20 and the observation target O, respectively, are rougher than the contact surfaces 31A and 31B. In other words, at least a portion of the surfaces of the elastic body 31 other than the contact surfaces with the sensor unit 20 and the observation target O, respectively, has a surface roughness rougher than the contact surfaces 31A and 31B. This randomizes the reflection and scattering of ultrasonic waves from the corresponding outer surface portions of the elastic body 31, reducing their effects. The surface having a surface roughness rougher than the contact surfaces 31A and 31B may be, for example, a surface provided with irregularities of a size and pitch appropriate for scattering ultrasonic waves depending on the transmission frequency.

[0038] The false target 32 ​​is an object (for example, metal) that can reflect a portion of the ultrasonic waves transmitted from the sensor unit 20 back toward the sensor unit 20 , and is contained within the elastic body 31 .

[0039] The pseudo target 32 ​​is placed in a region different from the region of interest corresponding to the observation target O in the elastic body 31. The region of interest is the internal region of the observation target O (piping), that is, the region that the user wants to observe, so the pseudo target 32 ​​is placed in at least one region of the regions B on both sides of the observation target O in the X direction, for example.

[0040] The false target 32 ​​is contained in the elastic body 31, which makes it possible to detect the deterioration state of the elastic coupler 30. Specifically, when the elastic coupler 30 dries and the amount of moisture contained in the elastic coupler 30 decreases, the ultrasonic transmittance decreases (i.e., the ultrasonic attenuation rate increases). This causes a change in the ultrasonic data (reflection intensity) acquired through the false target 32.

[0041] 4 is a diagram showing the change in mass characteristics of the elastic coupler 30 due to a drying experiment of the elastic coupler 30. The drying experiment was carried out by placing the elastic coupler 30 in a dryer and measuring the mass of the elastic coupler 30 over time.

[0042] The horizontal axis in Fig. 4 represents time. The vertical axis on the left side in Fig. 4 represents the mass of the elastic coupler 30. The vertical axis on the right side in Fig. 4 represents the reflection intensity acquired through the false target. The curve in Fig. 4 represents the change in mass over time. The diamonds in Fig. 4 represent the reflection intensity measured at that time.

[0043] The drying experiment confirmed that the moisture content of the elastic coupler 30 decreased with time, resulting in a decrease in mass. In addition, the drying experiment measured the first reflection intensity M1 and the second reflection intensity M2.

[0044] The first reflection intensity M1 is ultrasonic data acquired through the false target 32 ​​when the elapsed time is a first time T1 (e.g., about 20 hours). In this drying experiment, the reflection intensity characteristics shown in FIG. 5A were acquired, and M1 is a value corresponding to the maximum value.

[0045] The second reflection intensity M2 is the ultrasonic data acquired through the false target when the elapsed time is a second time T2 (e.g., about 170 hours). In this drying experiment, the reflection intensity characteristics shown in FIG. 5B were acquired, and M2 is the value corresponding to the maximum value.

[0046] The horizontal axis in FIGS. 5A and 5B represents distance, and the vertical axis in FIGS. 5A and 5B represents the amplitude of the reflected signal.

[0047] In this drying experiment, it was confirmed that the second reflection intensity M2 was approximately 1 / 4 to 1 / 3 of the first reflection intensity M1, and that the reflection intensity weakened as time passed. In other words, it was confirmed that as the drying of the elastic coupler 30 progressed, the moisture content decreased, resulting in a decrease in mass, and the ultrasonic transmittance decreased, resulting in a decrease in the reflection intensity acquired through the false target 32. In other words, by detecting a decrease in the reflection intensity acquired through the false target 32, it is possible to detect the deterioration state of the elastic coupler 30.

[0048] The evaluation unit 40 also evaluates the ultrasonic reflection component reflected from the false target 32, among the ultrasonic data received by the receiving unit 22. Specifically, the evaluation unit 40 outputs an evaluation result according to the magnitude of the ultrasonic component reflected from the false target 32.

[0049] More specifically, when the reflection intensity acquired through the false target 32 ​​is smaller than a first predetermined value, the evaluation unit 40 outputs an evaluation result indicating that the reflection intensity is smaller than the first predetermined value. Note that when the reflection intensity is equal to or greater than the first predetermined value, the evaluation unit 40 may output an evaluation result indicating that the reflection intensity is equal to or greater than the first predetermined value.

[0050] The first predetermined value can be set to an appropriate value, and may be, for example, a reflection intensity value corresponding to the mass (deterioration state) of the elastic coupler 30 that can ensure the reliability of the acquired data at a minimum level. The first predetermined value may also be a value based on a relative value that indicates a change in reflection intensity from an initial value.

[0051] The execution unit 50 outputs an alarm based on the evaluation result of the evaluation unit 40. Specifically, if the reflection intensity is smaller than a first predetermined value, the execution unit 50 outputs an alarm urging the user to replace the elastic coupler 30. The alarm may be in the form of voice, text display, or any other format as long as the content of the alarm can be recognized by the user. The execution unit 50 corresponds to the "alarm output unit" of the present invention.

[0052] Next, a description will be given of the flow of processing by the control unit 10. Fig. 6 is a flowchart showing an example of the operation of evaluation processing of ultrasound data by the control unit 10. This control is started when detection processing of the observation target O by the evaluation device 1, which will be described below, is started.

[0053] 6, the control unit 10 determines whether the reflection intensity acquired through the false target 32 ​​is equal to or greater than a first predetermined value (step S101). If the determination result indicates that the reflection intensity is less than the first predetermined value (step S101, NO), the control unit 10 outputs an alarm (step S102). After step S102, the elastic coupler 30 is replaced based on the alarm, and the process returns to step S101.

[0054] On the other hand, if the reflection intensity is equal to or greater than the first predetermined value (YES in step S101), the control ends. Note that the detection process of the observation target O by the evaluation device 1 is continuously performed, and the process according to this flowchart may be executed at regular intervals during the detection process.

[0055] According to the present embodiment configured as described above, the elastic coupler 30 interposed between the sensor unit 20 and the observation target O has an elastic body 31 and a pseudo target 32 ​​contained within the elastic body 31 and capable of reflecting part of the ultrasonic waves.

[0056] The reflection intensity of the ultrasonic data that passes through this false target 32 ​​decreases as the deterioration of the elastic coupler 30 progresses. In other words, by checking the change over time in the reflection intensity through the false target 32, it is possible to easily detect whether or not the elastic coupler 30 has deteriorated. This makes it possible to prevent the continued use of a deteriorated elastic coupler 30, thereby ensuring the reliability of the acquired data.

[0057] Data fluctuations may also occur due to deterioration of the sensor unit 20. In this case, if an elastic coupler without a false target is used, it is difficult to determine whether the cause of the data fluctuation is deterioration of the elastic coupler or deterioration of the sensor unit. In contrast, in this embodiment, the presence or absence of deterioration of the elastic coupler 30 can be detected based on the change over time in the reflection intensity via the false target 32, making the above determination easy.

[0058] Furthermore, for example, if a dummy target is placed closer to the sensor unit than the observation target O in the region of interest, the dummy target may prevent accurate detection of the observation target when an ultrasonic tomographic image is generated. This is because the dummy target is closer to the sensor unit than the observation target, and acts as a barrier to the ultrasonic waves heading toward the observation target, reducing the ultrasonic wave intensity and decreasing the detection accuracy of the observation target directly below it.

[0059] In this embodiment, the false target 32 ​​is placed in a region in the X direction that is different from the region of interest corresponding to the observation target O, so that the false target 32 ​​and the observation target O can be distinguished in the ultrasonic tomographic image. As a result, the false target 32 ​​is prevented from becoming a barrier to the ultrasonic waves directed toward the observation target O, so that the observation target O can be accurately detected.

[0060] Furthermore, the surfaces of the elastic body 31 other than the contact surfaces 31A and 31B with the sensor unit 20 and the observation target O, respectively, are configured as rougher surfaces than the contact surfaces 31A and 31B. As a result, the ultrasonic reflection and scattering components from the interface portions of the elastic body 31 can be randomized, reducing their influence.

[0061] Furthermore, the contact surface 31B of the elastic body 31 with the observation target O is a smooth surface, preventing unintended scattering or refraction of ultrasonic waves. Furthermore, since the elastic body 31 is configured to be able to fit onto the surface of the observation target O, the elastic body 31 can be brought into close contact with the observation target O, and the posture of the elastic body coupler 30 can be stabilized.

[0062] Furthermore, since the evaluation unit 40 evaluates the ultrasonic wave components reflected from the false target 32, the user can easily grasp the current state of the elastic coupler 30 based on the evaluation results.

[0063] Furthermore, the execution unit 50 outputs an alarm based on the evaluation result of the evaluation unit 40. Specifically, when the reflection intensity based on the ultrasonic component reflected from the false target 32 ​​is smaller than a first predetermined value, the execution unit 50 outputs an alarm.

[0064] This allows the user to easily recognize when to replace the elastic coupler 30, thereby preventing continued use of a deteriorated elastic coupler 30. As a result, ultrasonic data can be stably acquired when measuring the observation target O over a long period of time, and the reliability of the acquired data can be ensured.

[0065] In the above embodiment, the false target 32 ​​is arranged in one of the regions on either side of the observation target O in the width direction, but the present invention is not limited to this. For example, as shown in Fig. 7 , at least one false target 32 ​​may be provided in each of two regions B that sandwich the observation target O in the X direction.

[0066] By providing one false target 32 ​​in each of the two areas B, it becomes possible to detect whether the sensor unit 20 is tilted or not.

[0067] 8 is a diagram showing an example of an ultrasonic tomographic image acquired in a configuration in which one false target 32 ​​is provided in each of two regions B that sandwich the observation target O. For example, the false targets 32 are arranged at the same depth in the elastic body 31.

[0068] 8, it can be seen that the ultrasonic tomographic image has acquired portions 32A and 32B representing the false target 32. For example, by adjusting the inclination of the sensor unit 20 so that the positions of the portions 32A and 32B are at the same depth, it becomes possible to acquire appropriate ultrasonic data.

[0069] The false targets 32 may be arranged at different depths in the elastic body 31. In this case, the inclination of the sensor unit 20 may be adjusted so that the relative positional relationship between the ultrasound images 32A and 32B showing the false targets 32 in the ultrasound tomographic image is the same as the actual relative positional relationship between the false targets 32.

[0070] The evaluation unit 40 also outputs an evaluation result according to the positional relationship between the depth positions of the two false targets 32 provided in each of the two regions B in the ultrasonic tomographic image.

[0071] More specifically, if the difference between the depth positions is greater than the second predetermined value, the evaluation unit 40 outputs an evaluation result indicating that the difference is greater than the second predetermined value. Note that, if the difference between the depth positions is equal to or less than the second predetermined value, the evaluation unit 40 may output an evaluation result indicating that the difference is equal to or less than the second predetermined value.

[0072] The second predetermined value may be set to an appropriate value, for example, a value corresponding to the difference between the depth positions that can ensure the minimum reliability of the acquired data, or may be a value based on a relative value that indicates a change from an initial value of the difference between the depth positions.

[0073] If the difference is greater than the second predetermined value, the execution unit 50 adjusts the positional relationship between the sensor unit 20, the elastic coupler 30, and the observation target O. Specifically, the execution unit 50 adjusts the tilt of the sensor unit 20 so that the difference between the depth positions of the two pseudo targets 32 is equal to or less than the second predetermined value. The execution unit 50 corresponds to the "adjustment unit" of the present invention.

[0074] In addition, if the tilt of the sensor unit 50 exceeds the range in which the sensor unit 20 can be adjusted by the evaluation device 1, the execution unit 50 may output an alarm to urge the user to correct the tilt of the sensor unit 20.

[0075] Next, a description will be given of the flow of processing by the control unit 10. Fig. 9 is a flowchart showing an example of the operation of evaluation processing of ultrasound data by the control unit 10. This control is started when detection processing of the observation target O by the evaluation device 1, which will be described below, is started.

[0076] 9, the control unit 10 determines whether the difference between the depth positions of the two false targets 32 is equal to or less than a second predetermined value (step S103). If the result of the determination is that the difference between the depth positions is greater than the second predetermined value (step S103, NO), the control unit 10 adjusts the positional relationship between the sensor unit 20, the elastic coupler 30, and the observation target O (step S104).

[0077] After step S104, the process returns to step S103. Note that, if it is determined in step S103 after step S104 that the tilt of the elastic coupler 30 has not been resolved (the difference is greater than the second predetermined value), the above-mentioned warning may be output.

[0078] On the other hand, if the difference between the depth positions is equal to or less than the second predetermined value (step S103, YES), the process proceeds to step S101. The process from step S101 onwards is the same as that in Fig. 6. After step S102, the elastic coupler 30 may be replaced based on the alarm, and then the process may return to step S103.

[0079] In this configuration, at least one false target 32 ​​is provided in each of the two regions B that sandwich the observation target O in the X direction. This makes it easier to detect the tilt of the sensor unit 20. As a result, if a variation in the acquired data occurs due to the tilt of the sensor unit 20, it can be easily identified that the cause is the tilt of the sensor unit 20.

[0080] That is, in this configuration, it is possible to easily determine whether the cause of fluctuations in the acquired data is deterioration of the elastic coupler 30 or tilt of the sensor unit 20 portion.

[0081] 10 , a plurality of false targets 32 may be arranged side by side at a predetermined interval in at least one of two regions B sandwiching the observation target O in the width direction of the elastic body 31. The predetermined interval may correspond to the resolution of the sensor unit 20 in the lateral direction (X direction). Specifically, the predetermined interval may be, for example, at least one of an interval equal to or less than the wavelength of the ultrasonic waves transmitted from the sensor unit 20, an interval equal to or less than the spatial focusing size of the ultrasonic waves by the sensor unit 20, and an interval (arrangement interval) between adjacent piezoelectric elements in an array-type probe constituting the sensor unit 20. Note that the array-type probe here refers to a sensor having a configuration in which a plurality of piezoelectric elements are arranged in a line, and each probe transmits and receives ultrasonic waves.

[0082] By providing the false target 32 ​​in this manner, it becomes possible to determine whether or not the sensor unit 20 has deteriorated or broken down (hereinafter referred to as deterioration, etc.).

[0083] For example, if the sensor unit 20 is not degraded, the ultrasonic tomographic image will show that the multiple false targets 32 are spaced apart from one another. On the other hand, if the sensor unit 20 is degraded, the lateral resolution of the ultrasonic tomographic image will decrease, and the multiple false targets 32 will be connected to one another and displayed as a single unit. In other words, if the sensor unit 20 is degraded, the ultrasonic tomographic image will not show that the multiple false targets 32 are spaced apart from one another.

[0084] That is, by checking the ultrasonic tomographic image, it is possible to easily detect whether the sensor unit 20 has deteriorated.

[0085] Furthermore, the evaluation unit 40 outputs an evaluation result according to data of the plurality of false targets 32 in the ultrasonic tomographic image. Specifically, the evaluation unit 40 outputs an evaluation result according to the resolution of the plurality of false targets 32 in the ultrasonic tomographic image.

[0086] For example, if the interval between the plurality of false targets 32 in the ultrasonic tomographic image is smaller than a third predetermined value, the evaluation unit 40 outputs the evaluation result. Note that if the interval is equal to or greater than the third predetermined value, the evaluation unit 40 may output the evaluation result indicating that the interval is equal to or greater than the third predetermined value.

[0087] The third predetermined value can be set to an appropriate value, and may be, for example, a value corresponding to an interval that can ensure the minimum reliability of the acquired data. The interval can be defined by the actual distance, separation, point spread function, degree of integration, etc., of the multiple false targets 32.

[0088] The execution unit 50 outputs an alarm based on the evaluation result of the evaluation unit 40. Specifically, if the interval is smaller than a third predetermined value, the execution unit 50 outputs an alarm urging the user to replace the sensor unit 20. The alarm may be in the form of a voice, a text display, or any other type of alarm as long as the content of the alarm can be recognized by the user.

[0089] Next, a description will be given of the flow of processing by the control unit 10. Fig. 11 is a flowchart showing an example of the operation of evaluation processing of ultrasound data by the control unit 10. This control is started when the detection processing of the observation target O by the evaluation device 1 is started.

[0090] As shown in FIG. 11, if the control unit 10 determines in step S101 that the reflection intensity is equal to or greater than a first predetermined value, it determines whether the spacing between the multiple false targets 32 is equal to or greater than a third predetermined value (step S105).

[0091] If the determination result shows that the interval is smaller than the third predetermined value (NO in step S105), the control unit 10 outputs an alarm (step S106). After step S106, the sensor unit 20 is replaced based on the alarm, and then the process returns to step S101.

[0092] On the other hand, if the interval is equal to or greater than the third predetermined value (YES in step S105), this control ends. The detection process of the observation target O by the evaluation device 1 may be continuously performed, and the process according to this flowchart may be executed at regular intervals during the detection process. Furthermore, the processes of steps S103 and S104 in FIG. 9 may be combined with the flowchart in FIG. 11. In this case, it is necessary that at least one false target 32 ​​is provided in each of the two regions B, and that multiple false targets 32 as shown in FIG. 10 are provided in at least one of the two regions B.

[0093] In this configuration, a plurality of false targets 32 are provided at predetermined intervals in at least one of two regions sandwiching the observation target O in the width direction of the elastic body 31. The predetermined intervals correspond to the resolution of the sensor unit 20 in the lateral direction (X direction). Specifically, the predetermined intervals are at least one of the intervals equal to or less than the wavelength of the ultrasonic waves transmitted from the sensor unit 20, the intervals equal to or less than the spatial focusing size of the ultrasonic waves by the sensor unit 20, and the arrangement interval of the piezoelectric elements in the array-type probe that constitutes the sensor unit 20. This makes it possible to detect whether the resolution of the sensor unit 20 is good or bad.

[0094] As a result, if a change in the acquired data occurs due to deterioration of the sensor unit 20 or the like, the cause can be easily identified.

[0095] That is, in this configuration, it is easy to determine whether the cause of the fluctuation in the acquired data is deterioration of the elastic coupler 30 or deterioration of the sensor unit 20. Furthermore, by combining the configuration of Fig. 7 (the processing of Fig. 9), it is easy to determine whether the cause of the fluctuation in the acquired data is deterioration of the elastic coupler 30, tilt of the sensor unit 20, deterioration of the sensor unit 20, etc.

[0096] In addition, in the above embodiment, the material of the pseudo target 32 ​​was not particularly limited, but the pseudo target 32, which is made of the same material as a specified detection target within the observation target O, may be contained within the elastic body 31.

[0097] Specifically, the ultrasonic reflectivity of the false target 32 ​​is equivalent to the ultrasonic reflectivity of the predetermined detection target. Here, "equivalent" includes being the same as well as having a slight difference.

[0098] In this way, the ultrasonic reflectivity of the dummy target 32 ​​is equivalent to that of the detection target, so that the ultrasonic data (reflection intensity) of the detection target and the dummy target acquired by the sensor unit 20 can be equivalent. As a result, it becomes easier to estimate that a specific detection target is present within the observation object O.

[0099] Furthermore, the pseudo target 32 ​​may be arranged within the range in which the observation target O is located, for example, in the Y direction, so that the pseudo target 32 ​​is at the same position as the detection target within the observation target O.

[0100] By doing so, the reflection intensity of the ultrasonic waves reflected from the false target 32 ​​and the reflection intensity of the ultrasonic waves reflected from the detection target can be made more equivalent, which makes it easier to estimate that a specific detection target D is present within the observation object O.

[0101] The size of the false target 32 ​​may be equal to the size of the detection target within the observation target O. Since the size of the detection target D is, for example, within the range of several hundred μm to several mm, the size of the false target 32 ​​may be, for example, within the range of several hundred μm to several mm.

[0102] By doing so, the reflection intensity of the ultrasonic waves reflected from the specific detection target D becomes equal to the reflection intensity from the false target 32. Therefore, it becomes easier to detect that the material of the object detected from the observation target O is the specific detection target D. It also becomes easier to estimate the size of the object detected from the observation target O.

[0103] Furthermore, there is a possibility that multiple types of detection targets (e.g., metal, resin, semi-solid polymer, rubber pieces) may exist within the observation target O. Therefore, as shown in Fig. 12, multiple false targets 32 having materials, sizes, and shapes corresponding to the multiple types of detection targets may be contained within the elastic body 31. In other words, the false targets 32 may be at least one of the same size, material, and shape as a predetermined detection target within the observation target O.

[0104] However, ultrasonic tomographic images may differ from the ideal image due to the settings of the ultrasonic flaw detection device, so the acquired ultrasonic tomographic images need to be corrected. For example, ultrasonic tomographic images of a uniform medium that does not include an observation target have intensity distributions as shown in FIGS. 13A and 13B. FIG. 13A is an example of an image obtained using focused beamforming. FIG. 13B is an example of an image obtained using unfocused beamforming. For example, an ultrasonic tomographic image of a uniform medium is considered to be an ideal image in which the reflection intensity is uniform throughout the image. However, due to the settings of the ultrasonic flaw detection device, an ultrasonic tomographic image that differs from the ideal image may be obtained. For example, the image shown in FIG. 13A focuses the beam at a specific location (e.g., the central portion in the X direction), so the reflection intensity in the central portion is strongest. For example, the image shown in FIG. 13B shows that, if the beam is a plane wave, it diffuses spherically after passing a limit point (e.g., the central portion in the X direction). Therefore, the reflection intensity weakens, for example, from the center to the edge in the X direction. That is, in an ultrasonic tomographic image, the reflected intensity of ultrasonic waves is not uniform depending on at least one of the beamforming methods used during transmission and reception, and the reflected intensity may differ depending on the position in the X direction and the position in the Y direction. As a result, accurate observation results may not be obtained, and so the acquired ultrasonic tomographic image must be corrected.

[0105] Since the characteristics of an image obtained by the beamforming method can be known in advance, the execution unit 50 may correct the acquired ultrasonic tomographic image based on a predetermined map. The predetermined map may be, for example, an intensity variation map as shown in Figures 13A and 13B that depends on the beamforming method. The execution unit 50 corresponds to the "correction unit" of the present invention.

[0106] Specifically, the execution unit 50 corrects the acquired ultrasonic tomographic image so that, for example, the maximum reflection intensity becomes the minimum, and the minimum reflection intensity becomes the maximum, reversing the strength relationship of the reflection intensity distribution. In this way, the change in reflection intensity in the ultrasonic tomographic image that depends on the beamforming method can be corrected, and the correct reflection intensity can be detected. As a result, the detection performance of the detection target D can be improved.

[0107] Furthermore, the predetermined map is not limited to a map of intensity variation, and may be, for example, a map of image shape variation. When multiple targets of the same shape are uniformly arranged in the X and Y directions as shown in Fig. 14A, for example, when focused beamforming is used, an image such as that shown in Fig. 14B is acquired. That is, the image shape of the target varies depending on its position. For example, as shown in Fig. 14B, an image extending in the Y direction is formed as the distance from the focus center increases. In other words, the ultrasonic tomographic image may differ from the ideal image.

[0108] Therefore, the execution unit 50 may correct the acquired ultrasonic tomographic image based on an image shape variation map (predetermined map).

[0109] Specifically, the execution unit 50 corrects the ultrasonic tomographic image using an inverse function that changes the image shown in FIG. 14B to the image shown in FIG. 14A, for example.

[0110] In this way, it is possible to correct changes in the image shape in the ultrasonic tomographic image that depend on the beamforming method, and to obtain an image based on the correct shape, thereby improving the detection performance of the detection target D.

[0111] Furthermore, in the above embodiment, the pseudo target 32 ​​is placed at a position different from the observation target O in the X direction, but the present invention is not limited to this, and the pseudo target 32 ​​may be placed at a position overlapping the observation target O in the X direction.

[0112] Specifically, as shown in FIG. 15, the false target 32 ​​is provided in an area of ​​the elastic body 31 on the opposite side of the sensor unit 20 with respect to the observation target O.

[0113] In this way, if the false target 32 ​​appears in the ultrasonic tomographic image, it means that the ultrasonic waves are propagating to a position deeper than the observation target O. In other words, the false target 32 ​​makes it possible to confirm that the ultrasonic waves are propagating throughout the entire area of ​​the observation target O.

[0114] Furthermore, in the above embodiment, the ultrasound data acquisition device has an evaluation unit and an execution unit, but the present invention is not limited to this, and may not have an execution unit, or may not have both an evaluation unit and an execution unit. Furthermore, if the ultrasound data acquisition device does not have an execution unit, the user may check the evaluation result of the evaluation unit and take action corresponding to the evaluation result (e.g., adjusting the tilt of the sensor unit, replacing the elastic coupler, etc.). Furthermore, if the ultrasound data acquisition device does not have both an evaluation unit and an execution unit, the user may check the ultrasound tomographic image generated by the ultrasound data acquisition device and take action, for example, replacing the elastic coupler.

[0115] In addition, in the above embodiment, the execution unit serves as the alarm output unit, adjustment unit, and correction unit, but the present invention is not limited to this, and the alarm output unit, adjustment unit, and correction unit may be provided separately.

[0116] Furthermore, the above-described embodiments are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be carried out in various forms without departing from the gist or main features thereof.

[0117] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2023-204797, filed December 4, 2023, are incorporated herein by reference in their entirety.

[0118] REFERENCE SIGNS LIST 1 Evaluation device 10 Control unit 20 Sensor unit 21 Transmitter unit 22 Receiver unit 30 Elastic coupler 31 Elastic body 31A Contact surface 31B Contact surface 31C First part 31D Second part 32 Dummy target 40 Evaluation unit 50 Execution unit O Observation target D Detection target

Claims

1. An elastic coupler interposed between a sensor unit capable of transmitting and receiving ultrasonic waves and an object to be observed, comprising: an elastic body that propagates ultrasonic waves between the sensor unit and the object to be observed; and a pseudo target contained within the elastic body and capable of reflecting a portion of the ultrasonic waves.

2. The elastic body coupler according to claim 1, wherein the pseudo target is disposed in a region of the elastic body different from a region of interest corresponding to the observation target.

3. The elastic body coupler according to claim 2, wherein at least one of the pseudo targets is provided in each of two regions sandwiching the object to be observed in the width direction of the elastic body.

4. The elastic body coupler according to claim 2, wherein the pseudo target is provided in an area of ​​the elastic body on the opposite side of the sensor unit with respect to the object to be observed.

5. The elastic body coupler according to claim 2, wherein the pseudo targets are arranged side by side at a predetermined interval in the width direction and / or length direction of the elastic body, the interval corresponding to the resolution of the sensor section.

6. The elastic coupler according to claim 5, wherein the specified interval is at least one of an interval equal to or less than the wavelength of the ultrasonic wave, an interval equal to or less than the spatial focusing size of the ultrasonic wave by the sensor unit, and an array interval when the sensor unit is composed of a plurality of piezoelectric elements arranged in an array.

7. The elastic coupler according to claim 1, wherein the ultrasonic reflectivity of the pseudo target is equivalent to the ultrasonic reflectivity of a predetermined detection target within the observation target.

8. The elastic coupler according to claim 2, wherein the pseudo target is at least one of the following: a size equivalent to a predetermined detection target within the observation object, a material equivalent to the predetermined detection target, and a shape equivalent to the predetermined detection target.

9. The elastic body coupler according to claim 2, wherein at least a part of the surfaces of the elastic body other than the contact surfaces with the sensor unit and the object to be observed has a surface roughness rougher than that of the contact surfaces.

10. The elastic body coupler according to claim 1, wherein the contact surface of the elastic body with the object to be observed is configured to be able to fit onto the surface of the object to be observed.

11. An ultrasonic data acquisition device comprising: a sensor unit including a transmitting unit that transmits ultrasonic waves and a receiving unit that receives ultrasonic components reflected from a reflecting object to obtain ultrasonic data that can be used to construct an ultrasonic tomographic image; and an elastic body coupler interposed between the sensor unit and the object to be observed, the elastic body having an elastic body that propagates ultrasonic waves between the sensor unit and the object to be observed, and a pseudo target contained in the elastic body and capable of reflecting part of the ultrasonic waves.

12. The ultrasonic data acquisition device according to claim 11, wherein the receiving unit receives ultrasonic components reflected from the observation object and the pseudo target, and further comprises an evaluation unit that evaluates the ultrasonic components reflected from the pseudo target.

13. The ultrasound data acquisition device of claim 12, wherein the pseudo target is provided in each of two regions sandwiching the object to be observed in the width direction of the elastic body, at least one pseudo target being provided in each of the two regions, and the evaluation unit outputs an evaluation result according to the positional relationship of the depth positions of the two pseudo targets provided in each of the two regions in the ultrasound tomographic image.

14. The ultrasonic data acquisition device according to claim 12, wherein the evaluation unit outputs an evaluation result according to the magnitude of the ultrasonic component reflected from the pseudo target.

15. The ultrasound data acquisition device of claim 12, wherein the pseudo targets are arranged side by side at a predetermined interval in at least one of two regions sandwiching the object of observation in the width direction of the elastic body, and the evaluation unit outputs an evaluation result according to the interval between the multiple pseudo targets in the ultrasound tomographic image.

16. The ultrasound data acquiring device according to claim 12, further comprising an alarm output unit that outputs an alarm based on the evaluation result of the evaluation unit.

17. The ultrasonic data acquisition device according to claim 13, further comprising an adjustment unit that adjusts the inclination of the sensor unit according to the positional relationship.

18. The ultrasonic data acquiring device according to claim 12, further comprising a correction unit that corrects the ultrasonic data acquired by the receiving unit based on a predetermined map.

19. A method for acquiring ultrasonic data using an elastic coupler interposed between a sensor unit and an object to be observed, the elastic coupler having an elastic body that propagates ultrasonic waves between the sensor unit and the object to be observed, and a pseudo target that is contained in the elastic body and capable of reflecting a portion of the ultrasonic waves, the method comprising: transmitting the ultrasonic waves from the sensor unit; and receiving ultrasonic components reflected from a predetermined detection target and the pseudo target within the object to be observed, to acquire ultrasonic data that can be used to construct an ultrasonic tomographic image.

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