Wave analysis device, flaw detection device, wave analysis system, wave analysis method, and program

Abstract

Provided is a wave motion analysis device 100 that detects a defect in a body being scanned on the basis of reflected waves obtained from the body being scanned, the wave motion analysis device 100 comprising: a multiple-reflection region extraction unit 106 that acquires fault data generated on the basis of the reflected waves, and that extracts, from the fault data, a multiple-reflection region in which it is possible to mainly detect multiple-reflection signals in accordance with a depth range deeper than the depth at which an actual image of the body being scanned can actually be detected in the fault data; and a detection unit 107 that detects, from the extracted multiple-reflection region, a multiple-reflection image corresponding to a defect in the body being scanned.

Description

[Technical Field]

[0001] The present disclosure relates to a wave analysis device, a flaw detection device, and a method thereof, and in particular to a method for detecting defects such as foreign matter and peeling using multiple reflections. [Background technology]

[0002] In recent years, ultrasonic flaw detection methods have been used for non-destructive testing of structures. Ultrasonic flaw detection methods involve transmitting ultrasonic waves from a probe (ultrasonic probe) into a structure under test, receiving reflected waves of the ultrasonic waves resulting from differences in acoustic impedance within the structure under test, and generating ultrasonic tomographic images showing the state of the structure's interior based on the resulting electrical signals (see, for example, Non-Patent Document 1). This method is intended to detect defects around welds in structures, as well as defects on the surface or interior of integrally molded structures, and because it does not require large-scale auxiliary equipment such as shielding, as compared with radiographic testing, it has been proposed as a material evaluation method. For example, Patent Document 1 proposes a technology for performing ultrasonic testing by removing noise caused by multiple echoes generated within the rotating body of the ultrasonic probe from the received ultrasonic signals. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Masayasu Ito and Tsuyoshi Mochizuki, "Ultrasound Diagnostic Devices," Corona Publishing, August 26, 2002 [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-175519 Summary of the Invention [Problem to be solved by the invention]

[0005] The growth of composite materials, typified by CFRP (Carbon Fiber Reinforced Plastics), is expected to achieve both strength and light weight. However, CFRP is not as easy to process as metals, and its strength varies greatly depending on the degree of internal delamination and voids, as well as the degree of filler orientation deviation. To ensure the quality of its strength, there is a demand for flaw detection methods that can visualize the internal state of materials and components and inspect their functional performance.

[0006] However, composite materials such as CFRP often have a layered structure in which thin plate-like components are stacked, and when evaluating the quality of adhesion and bonding defects or surface coatings of components, defects such as peeling and foreign objects that are the target of inspection are often located in the shallow part of the component being inspected. Therefore, when detecting these defects using ultrasonic flaw detection methods, the reflected signal from the defect is buried in the specular reflection component, such as surface reflection, which has a large signal strength in shallow parts, making it difficult to accurately identify the signal from the defect and making it difficult to detect the defect with high accuracy.

[0007] Furthermore, when the inspection target is a defect such as poor adhesion or bonding between layers in a thin plate material with a layered structure, peeling in the surface coating, foreign matter, or voids, defects that are roughly perpendicular to the incident direction of the beam become strong reflectors, causing false images (artifacts) due to multiple reflections, making accurate measurement even more difficult. Conventionally, it has been common technical knowledge that artifacts due to multiple reflections are removed as noise that interferes with inspection, as described in Patent Document 1, for example.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a wave analysis device, a flaw detection device, a wave analysis system, a wave analysis method, and a program that are capable of detecting defects located in shallow parts of an inspected component even when surface reflection is present. [Means for solving the problem]

[0009] A wave analysis device according to one aspect of the present disclosure is a wave analysis device that detects defects in an object under test based on reflected waves obtained from the object under test, and is characterized by comprising a multiple reflection area extraction unit that acquires tomographic data generated based on the reflected waves and extracts multiple reflection areas from the tomographic data, and a detection unit that detects multiple reflection images corresponding to defects in the object under test from the extracted multiple reflection areas. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to provide a wave analysis device, a flaw detection device, a wave analysis system, a wave analysis method, and a program that are capable of detecting defects located in shallow parts of an inspected component even when surface reflection is present. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a functional block diagram showing the configuration of an ultrasonic flaw detector 100 constituting an ultrasonic flaw detector set 1000 according to a first embodiment. [Figure 2] 1 is a schematic diagram showing an ultrasonic flaw detection device set 1000 in use. FIG. [Figure 3] 2 is a functional block diagram showing the configuration of a reflected signal acquisition unit 104 in the ultrasonic flaw detection device 100. FIG. [Figure 4] 1A and 1B are schematic diagrams showing an overview of the operation of transmitting and receiving beamforming in the ultrasonic flaw detector 100. FIG. [Figure 5] 1 is a functional block diagram showing the configuration of a tomographic data generating unit 105, a multiple reflection region extracting unit 106, a detecting unit 107, and an output control unit 108 in an ultrasonic flaw detection device 100. FIG. [Figure 6] 10(a) and 10(b) are schematic diagrams for explaining the operation of the multiple reflection region extraction unit 106 when the object under inspection 300 does not include a defect DF. [Figure 7] 10(a) and 10(b) are schematic diagrams for explaining the operation of the multiple reflection region extraction unit 106 when the object under inspection 300 contains a defect DF. [Figure 8](a) is a schematic diagram showing an example of a display image drawn on the display unit 111 in an embodiment of the flaw detection device 100 when the object to be inspected 300 does not contain a defect DF, and (b) is a schematic diagram showing an example of a display image drawn on the display unit 111 in an embodiment of the flaw detection device 100 when the object to be inspected 300 contains a defect DF parallel to the surface. [Figure 9] 3 is a flowchart showing the operation of the ultrasonic flaw detector 100. [Figure 10] FIG. 10 is a functional block diagram showing the configuration of a transmission beam former 103A, a reflected signal acquisition unit 104A, a tomographic data generation unit 105, a multiple reflection region extraction unit 106, a detection unit 107, and an output control unit 108 in an ultrasonic flaw detection device 100A according to embodiment 2. [Figure 11] 10(a) and 10(b) are diagrams showing an example of a display image drawn on the display unit 111 in the embodiment of the ultrasonic flaw detection device 100A. [Figure 12] 10(a) and 10(b) are diagrams showing an example of a display image drawn on the display unit 111 in the embodiment of the ultrasonic flaw detection device 100A. [Figure 13] 4 is a flowchart showing the operation of the ultrasonic flaw detector 100A. [Figure 14] 10 is a functional block diagram showing the configurations of a detection unit 107B and an output control unit 108B in an ultrasonic flaw detection apparatus 100B according to a third embodiment. FIG. [Figure 15] 3 is a schematic diagram for explaining the operation of the ultrasonic flaw detector 100B. FIG. [Figure 16] 4 is a flowchart showing the operation of the ultrasonic flaw detector 100B. [Figure 17] 1 is a schematic configuration diagram of an ultrasonic flaw detection system 1 according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] An ultrasonic flaw detection method according to a first embodiment and an ultrasonic flaw detection device using the same will be described in detail below with reference to the drawings.

[0013] First Embodiment The ultrasonic flaw detector 100 according to the first embodiment will be described below with reference to the drawings.

[0014] FIG. 1 is a functional block diagram of an ultrasonic flaw detection set 1000 according to the first embodiment. As shown in FIG. 1, the ultrasonic flaw detection set 1000 includes a probe 101 (ultrasonic probe) having a plurality of transducers 101a that transmit ultrasonic waves toward an object under test and receive the reflected waves, an ultrasonic flaw detection device 100 that causes the probe 101 to transmit and receive ultrasonic waves and generates image data based on an output signal from the probe 101, and a display unit 111 that displays an ultrasonic image on a screen. The probe 101 and the display unit 111 are each configured to be connectable to the ultrasonic flaw detection device 100. FIG. 1 shows a state in which the probe 101 and the display unit 111 are connected to the ultrasonic flaw detection device 100. Note that the probe 101 and the display unit 111 may be located inside the ultrasonic flaw detection device 100.

[0015] FIG. 2 is a schematic diagram showing the relationship between the ultrasonic flaw detector 100 and the object under test 300. As shown in FIG.

[0016] The test object 300 is a plate-shaped member. For example, it may be made of a composite material such as CFRP. Composite materials such as CFRP are useful for achieving both strength and light weight. In order to reduce the weight of various mobilities and devices toward a low-carbon society, structural members used in space probes, artificial satellites, wind power generation facilities, etc. are being shifted from metal materials such as iron to light metals, and even carbon fiber reinforced plastics, as well as multi-materials made by combining and bonding these materials.

[0017] 2, the probe 101 is held by a holding member 211 connected to a housing 220. The device under test 300 is arranged parallel to the transducer surface of the probe 101. The holding member 211 has at least the function of being able to adjust the orientation of the probe 101 in the minor axis direction of the probe 101 and being able to hold the probe 101 in a desired orientation.

[0018] The object to be inspected 300 may be, for example, a composite member such as an FRP cast molding, a composite material, a metal or resin, or a multi-material made by combining and bonding these, or a structural member having a layered structure in which thin plate-like members are stacked, but is not limited to these.

[0019] During measurement, the probe 101 is held by the holding member 211 in such a manner that at least the entire vibrator surface is close to but separated from the surface of the test object 300 by a small distance, and the space between the surface of the test object 300 and the vibrator surface of the probe 101 is filled with, for example, ultrasonic gel (not shown).

[0020] <Configuration of ultrasonic flaw detector 100> The ultrasonic flaw detection device 100 includes a multiplexer unit 102 that selects one of the multiple transducers 101a of the probe 101 to be used for transmission or reception and ensures input and output to the selected transducer, a transmission beam former unit 103 that controls the timing of applying high voltage to each transducer 101a of the probe 101 to transmit ultrasonic waves, and a reflected signal acquisition unit 104 that amplifies, A / D converts, and receives beamforming electrical signals obtained by the multiple transducers 101a based on the reflected waves of ultrasonic waves received by the probe 101 to generate acoustic line signals. The system also includes a tomographic data generation unit 105 that generates tomographic data based on the output signal from the reflection signal acquisition unit 104, a multiple reflection area extraction unit 106 that extracts predetermined data areas that can be the subject of analysis from the tomographic data, a detection unit 107 that identifies and analyzes the data to be analyzed from the extracted data areas to determine whether or not there is a defect, an output control unit 108 that generates a display image showing the determination result, a data storage unit 110 that stores the acoustic line signal output by the reflection signal acquisition unit 104 and the tomographic data output by the tomographic data generation unit 105, and a control unit 109 that controls each component.

[0021] Of these, the multiplexer unit 102, the transmission beam former unit 103, the reflected signal acquisition unit 104, the tomographic data generation unit 105, the multiple reflection region extraction unit 106, the detection unit 107, and the output control unit 108 constitute an ultrasound signal processing device 150. In addition, the multiple reflection region extraction unit 106, the detection unit 107, and the output control unit 108 constitute an ultrasound signal analysis device 160.

[0022] Each of the components constituting the ultrasonic flaw detection device 100, such as the multiplexer unit 102, the transmit beam former unit 103, the reflected signal acquisition unit 104, the tomographic data generation unit 105, and the control unit 109, is implemented by a hardware circuit such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). Alternatively, the components may be implemented by a programmable device such as a processor and software. A central processing unit (CPU) or a graphics processing unit (GPU) can be used as the processor, and a configuration using a GPU is called a general-purpose computing on graphics processing unit (GPGPU). These components can be implemented as a single circuit component or as a collection of multiple circuit components. Furthermore, multiple components can be combined into a single circuit component or as a collection of multiple circuit components.

[0023] The data storage unit 110 is a computer-readable recording medium, and may be, for example, a flexible disk, a hard disk, an MO, a DVD, a DVD-RAM, a BD, a semiconductor memory, etc. The data storage unit 110 may also be a storage device externally connected to the ultrasonic flaw detection device 100.

[0024] It should be noted that the ultrasonic flaw detector 100 according to the first embodiment is not limited to the ultrasonic flaw detector having the configuration shown in Fig. 1. For example, the multiplexer unit 102 may be omitted, and the transmission beam former unit 103 and the reflected signal acquisition unit 104 may be directly connected to each transducer 101a of the probe 101. Alternatively, the transmission beam former unit 103, the reflected signal acquisition unit 104, or parts thereof may be built into the probe 101. This is not limited to the ultrasonic flaw detector 100 according to the first embodiment, but also applies to ultrasonic flaw detectors according to modified examples described later.

[0025] <Configuration of ultrasonic flaw detector 100> The transmission beam former 103, the reflected signal acquisition unit 104, the tomographic data generation unit 105, the multiple reflection region extraction unit 106, the detection unit 107, and the output control unit 108 of the ultrasonic flaw detection device 100 will be described below.

[0026] (Transmit beam former 103) The transmit beam former unit 103 is connected to the probe 101 via the multiplexer unit 102, and controls the timing of applying high voltage to transmitting transducers corresponding to all or some of the multiple transducers 101a in the probe 101 in order to transmit ultrasound from the probe 101. The transmit beam former unit 103 is composed of a transmitter unit 1031.

[0027] The transmitter 1031 performs a transmission process based on a transmission control signal from the controller 109, supplying a pulsed transmission signal to a transmitting transducer Tx among the multiple transducers 101a in the probe 101 to cause the transducer Tx to transmit an ultrasonic beam.

[0028] The transmitting unit 1031 may drive each transmitting transducer individually to generate an ultrasonic beam from the single transducer. Alternatively, a configuration may be adopted in which multiple transmitting transducers are driven in parallel. In the transmission process, a delay time may be set for the transmission timing of the ultrasonic beam for each transducer, and the transmission of the ultrasonic beam may be delayed by the delay time to form a wavefront of a desired shape, thereby focusing the ultrasonic beam. The number of transmitting transducers to be driven in parallel can be set arbitrarily, for example, for the transducer 101a in the probe 101. In this specification, ultrasonic transmissions performed in parallel are referred to as "transmission events."

[0029] Fig. 4(a) is a schematic diagram showing an overview of the operation of transmit beamforming in the ultrasonic flaw detection device 100. As shown in Fig. 4(a), in one transmission event, transmission waves are transmitted vertically downward from multiple transmitting transducers Tx. Furthermore, the transmitting unit 1031 repeats ultrasonic transmission while gradually moving the transmitting transducers Tx in the column direction for each transmission event, and transmits ultrasonic waves from all transducers 101a in the probe 101.

[0030] (Reflected signal acquisition unit 104) The reflected signal acquiring unit 104 generates acoustic line signals from electrical signals obtained by the multiple transducers 101a based on the reflected waves of the ultrasound waves received by the probe 101. The "acoustic line signals" refer to reflected signals that have undergone delay-and-sum processing. The delay-and-sum processing will be described later. FIG. 3 is a functional block diagram showing the configuration of the reflected signal acquiring unit 104. As shown in FIG. 3, the reflected signal acquiring unit 104 includes a receiving unit 1041, a reflected signal holding unit 1042, and a delay-and-sum unit 1043.

[0031] The configuration of each component of the reflected signal acquisition unit 104 will be described below.

[0032] The receiving unit 1041 is connected to the probe 101 via the multiplexer unit 102, and is a circuit that amplifies the electrical signals obtained by receiving reflected ultrasonic waves at the probe 101 in synchronization with transmission events, and then generates AD-converted reflected signals (RF signals). The receiving unit 1041 generates reflected signals in chronological order in the order of transmission events and outputs them to the reflected signal holding unit 1042, which holds the reflected signals. Here, the reflected signals (RF signals) are digital signals obtained by A / D-converting electrical signals converted from reflected ultrasonic waves received by each transducer, and form a string of signals linked in the transmission direction (depth direction of the subject) of the ultrasonic waves received by each transducer.

[0033] FIG. 4(b) is a schematic diagram showing an overview of the operation of receive beamforming in the reflected signal acquisition unit 104, illustrating the operation of generating an RF signal sequence based on reflected ultrasound from an observation point P, which is an arbitrary imaginary point. The receiving unit 1041 generates a sequence of reflected signals RF for each receiving transducer Rw based on reflected ultrasound acquired by each of the receiving transducers Rw arranged in a row, which corresponds to some or all of the multiple Nx transducers 101a in the probe 101, in synchronization with a transmission event. The receiving transducers Rw are selected by the control unit 109 via the multiplexer unit 102. In the first embodiment, the row center of the row Rwx of the reflecting transducers Rw formed by the receiving transducers Rw is selected to coincide with the row center of the transmitting transducers Tx. The number Mx of receiving transducers Rw may be set to be greater than the number of transmitting transducers, or may be set to the total number Nx of transducers 101a in the probe 101.

[0034] The transmitting unit 1031 repeatedly transmits ultrasound waves while gradually moving the transmitting transducer Tx in the column direction for each transmission event, and the receiving unit 1041 generates a column of reflected signals RF for the receiving transducer Rw for each transmission event, and the column of reflected signals RF is stored in the reflected signal storage unit 1042.

[0035] The reflected signal holding unit 1042 is a computer-readable recording medium, and may be, for example, a semiconductor memory. The reflected signal holding unit 1042 receives a sequence of reflected signals from the transmitting unit 1031 to each receiving transducer in synchronization with a transmission event, and holds the signals until the delay-and-sum process is performed. The reflected signal holding unit 1042 may be a storage device externally connected to the ultrasonic flaw detection apparatus 100, or a part of the data storage unit 110 built into the ultrasonic flaw detection apparatus 100.

[0036] The delay-and-sum unit 1043 is a circuit that generates an acoustic line signal by delaying and summing reflected signal sequences received by each reflecting transducer from multiple observation points P defined within a calculation target region Bx within the subject in synchronization with a transmission event. A "calculation target region" refers to a region in which an acoustic line signal is generated in synchronization with a single transmission event. As shown in FIG. 6(b), the calculation target region Bx may be a linear region corresponding to a single transducer in the azimuth direction. In this case, a single continuous acoustic line signal composed of signals from multiple observation points P arranged in the linear region is generated by delaying and summing reflected signal sequences received by each receiving transducer. Alternatively, the calculation target region Bx may be a region having a predetermined width in the azimuth direction corresponding to multiple transducers. In this case, the calculation target regions Bx set for each transmission event overlap each other in the azimuth direction, and the signals in the overlapping portions are combined by a combining unit 10433 (described later). That is, acoustic line signals at multiple observation points P within a calculation region Bx, which are generated in synchronization with multiple transmit events, are combined to generate one frame of acoustic line signals. A "frame" refers to a unit that forms a single group of signals necessary to construct one ultrasonic tomographic image. The calculation region Bx, in which acoustic line signals are generated in synchronization with transmit events, may be, for example, a linear region that passes through the center of the receive aperture Rx array, is perpendicular to the transducer array, and has a width of a single transducer, but is not limited to this and may be set to any region.

[0037] 3, the phasing addition unit 1043 includes a delay processing unit 10431, an addition unit 10432, and a synthesis unit 10433. The configuration of each unit will be described below.

[0038] The delay processing unit 10431 is a circuit that identifies, from the sequence of reflected signals RF for the receiving transducers Rw, the reflected signal corresponding to the delay amount for each receiving transducer Rw as the reflected signal corresponding to each receiving transducer Rw based on the reflected ultrasound from the observation point P.

[0039] The delay processing unit 10431 calculates the amount of delay to be applied to the sequence of reflected signals for each receiving transducer Rw based on information indicating the position of the observation point P, in synchronization with the transmission of the ultrasonic beam, acquires the reflected signals corresponding to the receiving transducer Rw from the reflected signal holding unit 1042, identifies the reflected signals corresponding to the time obtained by subtracting the amount of delay for each receiving transducer Rw from the sequence of reflected signals RF corresponding to each receiving transducer Rw, as reflected signals based on the reflected waves from the observation point P, and outputs them to the adding unit 10432. The amount of delay to be applied is calculated based on the distance between the transducer located on the central axis of the transmitted ultrasonic beam and each transducer 101a.

[0040] The adder 10432 is a circuit that receives the reflected signals identified for each receiving transducer Rw output from the delay processor 10431, adds them together, and generates a phased and added acoustic line signal for the observation point P. Alternatively, the adder 10432 may be further configured to multiply the reflected signals identified for each receiving transducer Rw by the reception apodization for each receiving transducer Rw and add the results to generate an acoustic line signal for the observation point P.

[0041] From one transmission event and the associated processing, acoustic line signals can be generated for all observation points P within the calculation region Bx. Then, for each transmission event, ultrasonic transmission is repeated while gradually moving the transmitting transducer Tx in the column direction, and ultrasonic waves are transmitted from all transducers 101a in the probe 101. The acoustic line signals for the calculation region Bx generated for each transmission event are output to the tomographic data generator 105 for each transmission event.

[0042] Furthermore, in a configuration in which calculation target regions Bx set for each transmission event overlap each other in the azimuth direction, a synthesis unit (not shown) may be provided downstream of the adder 10432 to synthesize a frame acoustic line signal from acoustic line signals for the calculation target region Bx generated in synchronization with the transmission events. The synthesis unit gradually inputs acoustic line signals generated for multiple observation points P within the calculation target region Bx from the adder 10432 in synchronization with the transmission events, and synthesizes a frame acoustic line signal by synthesizing the acoustic line signals for each observation point P using the position of the observation point P at which the acoustic line signal was acquired as an index. As described above, ultrasound transmission is performed sequentially by gradually shifting the transmitting transducer Tx in the transducer array direction in synchronization with the transmission events. Therefore, the position of the calculation target region Bx based on different transmission events also gradually changes in the same direction for each transmission event. By synthesizing the frame acoustic line signals using the position of the observation point P at which the acoustic line signal was acquired as an index, frame acoustic line signals covering all of the calculation target regions Bx are synthesized. The synthesized acoustic line signals for one frame are output to the tomographic data generator 105.

[0043] (Fault data generation unit 105) The tomographic data generating unit 105 acquires the acoustic line signals output from the delay-and-sum unit 1043, converts them into brightness values, and converts them into a Cartesian coordinate system to convert them into tomographic data (tomographic images). Fig. 5 is a functional block diagram showing the configurations of the tomographic data generating unit 105, the multiple reflection region extracting unit 106, the detecting unit 107, and the output control unit 108.

[0044] The tomographic data generation unit 105 includes an envelope detection and logarithmic compression unit 1051, and a coordinate conversion unit 1052. Conversion to brightness values ​​is performed by performing envelope detection on the acoustic line signal to remove the frequency components of the transmitted ultrasonic waves, and then performing logarithmic compression to improve the contrast of the ultrasonic tomographic image.

[0045] The coordinate conversion to the Cartesian coordinate system is performed, for example, by converting information indicating the position of observation point P, which is represented by the arrangement direction of transducer 101a and the time direction of the reflected signal, into XZ coordinates corresponding to the lateral direction and depth of the cross section of the object to be inspected.

[0046] The tomographic data generating unit 105 repeats the above process for each transmission event, generates one frame of tomographic data based on one frame of acoustic line signals, and outputs the generated data to the multiple reflection region extracting unit 106 .

[0047] (Multiple reflection area extraction unit 106) The multiple reflection region extraction unit 106 extracts, from the acquired tomographic data, a multiple reflection region that corresponds to a depth range deeper than the depth at which a real image of the object can be detected and from which multiple reflection signals can be detected, as a data region that can be analyzed. The multiple reflection region extraction unit 106 includes a specific time region designation unit 1061 and a luminance signal extraction unit 1062.

[0048] 6(a) and 6(b) are schematic diagrams for explaining the operation of the multiple reflection region extraction unit 106. FIG.

[0049] As shown in Figure 6(a), when the transducer array 101a of the probe 101 is placed facing the surface of the object to be inspected 300 with gel sandwiched between them, the transducer array 101a of the probe 101 is driven and an ultrasonic beam is emitted from the transducer array 101a toward the inspection target area of ​​the object to be inspected 300. Reflected waves from the inspection target area are received by the transducer array 101a, and tomographic data is obtained based on this reflected signal.

[0050] 6(b), a tomographic image 300RI based on a reflected signal obtained from the inspection target range of the inspection object 300 is displayed in the image based on the tomographic data. In this specification, a data portion in the tomographic data corresponding to the inspection target range of the inspection object 300 is referred to as a real image area RIA.

[0051] 7(a) and 7(b) are schematic diagrams for explaining the operation of the multiple reflection region extraction unit 106 when a defect to be inspected, such as peeling or a foreign substance, exists in the inspection object 300.

[0052] When the object under test 300 is a composite material such as CFRP, which has a layered structure of laminated thin plate-like members, defects DF such as peeling, foreign matter, and voids that are inspected in evaluating the quality of the adhesion / bonding or surface coating of the member are often layer defects parallel to the surface of the object under test 300. When an ultrasonic beam is transmitted from the transducer array 101a of the probe 101 to the object under test 300 containing such defects, the ultrasonic beam is incident on the defect DF approximately perpendicularly, as shown in Figure 7(a), and the defect DF becomes a strong reflector. Then, a reflected wave with a high intensity is incident on the transducer array 101a, and multiple reflections occur, where the wave is repeatedly reflected between the transducer array 101a and the defect DF.

[0053] In this case, in the image based on the tomographic data, as shown in FIG. 7(b), a tomographic image 300RI based on reflected waves from the inspection target range of the inspected object 300 is displayed in the real image area RIA, and a multiple reflection image MRI is displayed as a band-shaped high-brightness area extending in the Z direction, including multiple high-brightness lines arranged at a predetermined pitch in the depth direction and extending in the X direction, in an area corresponding to a depth range deeper than the inspection target range of the inspected object.

[0054] In this specification, a data portion in the tomographic data that corresponds to a depth range deeper than the inspection target range of the inspection object 300 and where multiple reflection signals are easily detected is referred to as a multiple reflection region MRA (virtual image region VIA).

[0055] These false images (artifacts) caused by multiple reflections can be an obstacle to accurate measurement, and have been conventionally thought to be something that should be removed. For example, Patent Document 1 proposes a technique for removing noise caused by multiple reflection echoes from a received ultrasonic signal using a filter. In other words, it has conventionally been common technical knowledge that artifacts caused by multiple reflections are noise that hinders inspection, and are therefore removed, as described in Patent Document 1, for example.

[0056] In contrast, in the multiple reflection region extraction unit 106 according to the present disclosure, the specific time region designation unit 1061 designates a time region having a predetermined length, which is equal to or longer than the time required for reflected waves from the inspection target region of the object under test 300 to arrive, as the specific time region. The area in the tomographic data where image data exists based on the reflected signals obtained in the specific time region is identified as the multiple reflection region MRA. Signals from the multiple reflection region MRA are primarily used as analysis target signals for defect DF detection. Therefore, the specific time region may be configured to be equal to or longer than the time required for ultrasonic waves to arrive from the depth of the inspection target region of the object under test 300. If the thickness of the object under test 300 is predetermined, the specific time region may use a value preset in the specific time region designation unit 1061. Alternatively, the specific time region may be configured to be input by the operator based on the inspection target region of the object under test 300 depicted in the real image region RIA.

[0057] The luminance signal extraction unit 1062 extracts the luminance signal of the multiple reflection region MRA from the tomographic data and outputs it to the detection unit 107.

[0058] (Detection unit 107) The detection unit 107 selects and analyzes analysis target image data OL from the tomographic data of the multi-reflection region MRA, and detects a multi-reflection image MRI corresponding to a defect DL in the object under test 300. The detection unit 107 includes an analysis target line identification unit 1071, a threshold setting unit 1072, and a determination unit 1073.

[0059] 8(a) is a diagram showing an example of a display image drawn on the display unit 111 in an embodiment of the flaw detection device 100 when the object under test 300 does not contain a defect DF, and (b) is a diagram showing an example of a display image drawn on the display unit 111 in an embodiment of the flaw detection device 100 when the object under test 300 contains a defect DF parallel to the surface. The operation of the detection unit 107 will be described using these display images.

[0060] The analysis target line specifying unit 1071 selects line data located at a predetermined depth ZP as an analysis target line OL from the tomographic data of the multiple reflection region MRA. A plurality of analysis target lines OL may be selected at different depths ZP.

[0061] The threshold setting unit 1072 sets the brightness threshold TH. At this time, the brightness threshold TH may be determined based on, for example, the average brightness of the tomographic data of the multiple reflection region MRA.

[0062] 8(b), if the line data of the analysis target line OL contains a data portion that exceeds the threshold brightness TH in a stepped manner over a predetermined length or more, the determination unit 1073 determines and detects the data portion as a multiple reflection image MRI representing a defect DF in the object under inspection 300. Conversely, if the line data of the analysis target line OL does not contain a stepped data portion that exceeds the threshold brightness TH as shown in FIG. 8(a), the determination unit 1073 determines that a multiple reflection image MRI representing a defect DF in the object under inspection 300 does not exist.

[0063] This allows the line to be analyzed OL to be selected from the multiple reflection area MRA located in a depth range deeper than the inspection target range of the object to be inspected 300, and detects the presence or absence of a multiple reflection image MRI representing the defect DF of the object to be inspected 300, making it possible to detect the defect DF of the object to be inspected 300 without being influenced by the strong regular reflection component (high brightness part) in the surface reflection image SRI in the real image area RIA corresponding to the inspection target range in the shallow part of the object to be inspected 300, as shown in Figures 8(a) and (b).

[0064] (output control unit 108) The output control unit 108 includes a judgment result display image generation unit 1081, which generates a display image showing the judgment result, including, for example, an identification image and text information indicating whether or not the object to be inspected 300 has a defect DF, and outputs the image to the display unit 111.

[0065] <Operation> The operation of the ultrasonic flaw detector 100 configured as above will be described.

[0066] FIG. 9 is a flowchart showing the operation of the ultrasonic flaw detector 100.

[0067] First, in step S10, the number of transmission events l is initialized, transmission processing is performed to transmit an ultrasonic beam from the transmitting transducer Tx of the probe 101 (step S20), reception processing is performed to generate a reflected signal based on the reflected wave received by the receiving transducer array (step S30), and the reflected signal is phased and added to generate an acoustic line signal (step S40).

[0068] Next, it is determined whether the number of transmission events I is at the maximum value (step S50). If it is not at the maximum value (step S50: No), I is incremented (step S60) and the process returns to step S20, where the transmitting transducer Tx is gradually moved to perform the processes of steps S20 to S40. If it is at the maximum value (step S50: Yes), the generation of one frame of acoustic line signal is completed and the process proceeds to step S80.

[0069] Next, in step S80, envelope detection, logarithmic compression, and coordinate transformation are performed on one frame of acoustic line signals to generate one frame of tomographic data.

[0070] Next, the multi-reflection region MRA is identified from the tomographic data and the brightness signal is extracted (step S90), the depth ZP of the line to be analyzed is identified (step S100), a brightness threshold TH is set (step S110), and the brightness signal of the line to be analyzed OL is extracted (step S120).

[0071] Next, it is determined whether or not there is an area exceeding a brightness threshold of a predetermined length or more (step S130). If there is an area (step S130: Yes), it is determined that a multiple reflection image MRI is detected (step S140) and that a defect DF is present (step S141). If there is no area (step S130: No), it is determined that a multiple reflection image MRI is not detected (step S150) and that no defect DF is present (step S151). The determination result is displayed on the display unit 111 (step S160), and the process ends.

[0072] <Small summary> When the inspected object 300 is a member with a layered structure made up of laminated thin plate-like members, such as CFRP, defects such as peeling and foreign matter that are the target of inspection when evaluating the quality of the member's adhesion, bonding, or surface coating are located shallow within the inspected member. However, in shallower regions, the influence of specular reflection components such as surface reflection, which has a large signal strength, is strong, and the reflected waves from defects are buried, making it difficult to clearly identify the signal from the defect and accurately detect the defect. Furthermore, when the inspection target is defects such as poor interlayer adhesion or bonding in thin plate materials, peeling, foreign matter, or voids in surface coatings, defects perpendicular to the incident direction act as strong reflectors, causing multiple reflections and making accurate measurement even more difficult.

[0073] Furthermore, as described in Patent Document 1, for example, it has been common technical knowledge that artifacts due to multiple reflections are removed as noise that impedes inspection.

[0074] In response to this, the inventors have conducted extensive research and have come up with a solution to the above-mentioned problems by deliberately utilizing multiple reflections.

[0075] Specifically, the ultrasound signal analysis device 160 according to the first embodiment is configured to extract from the tomographic data a multi-reflection region MRA that corresponds to a depth range deeper than the depth at which the real image of the object 300 can be detected and in which multiple reflection signals can be mainly detected, and to select and analyze image data to be analyzed from the multi-reflection region MRA to detect a multi-reflection image MRI that corresponds to the defect DF of the object 300.

[0076] With this configuration, it is possible to select an analysis line OL from the multiple reflection area MRA located in a depth range deeper than the inspection target range of the inspected object 300, and detect defects DF in the inspected object 300 without being affected by strong specular reflection components such as surface reflection in the real image area RIA corresponding to the inspection target range in the shallow part of the inspected object 300.

[0077] In other words, the real image area RIA has a stronger specular reflection component than the multiple reflection area MRA, making it difficult to accurately detect defects DF. Therefore, by avoiding defect DF detection that uses the signal in the real image area RIA as the analysis target and instead focusing on the signal from the multiple reflection area MRA, where multiple reflections are depicted, it becomes possible to accurately detect defects located in shallow parts of the inspected material even when surface reflections are present.

[0078] Furthermore, the image data to be analyzed is line data located at a predetermined depth, and if there is a data portion in the line data that exceeds the threshold brightness in a stepped manner over a predetermined length or more, the data portion is judged to be a multiple reflection image and detected.By adopting a configuration that uses a simple configuration, it is possible to select the line to be analyzed OL from the multiple reflection region MRA and detect the presence or absence of a multiple reflection image MRI that represents a defect DF in the object to be inspected 300.

[0079] Second Embodiment The ultrasonic flaw detection device 100 according to the first embodiment is configured to identify a multiple reflection region MRA corresponding to a depth range deeper than the depth at which a real image of the object under test 300 can be detected, and the detection unit 107 extracts line data located at a predetermined depth from the multiple reflection region MRA as image data to be analyzed, and if the line data contains a data portion that exceeds the threshold brightness TH in a stepped manner over a predetermined length or more, the data portion is determined to be a multiple reflection image MRI. However, the method for detecting the image data to be analyzed and the multiple reflection image MRI is not limited to this.

[0080] The ultrasonic flaw detection device 100A and its ultrasonic signal analyzer 160 according to the second embodiment differ from those of the first embodiment in that they are configured to select, as the image data to be analyzed, planar cross-sectional image data in the planar direction of the object to be inspected that corresponds to a specific depth included in the multiple reflection region MRA, and to detect multiple reflection images MRI using principal component analysis (PCA) for the spatial frequency of the image data. This method makes it possible to more accurately detect defects located in shallow parts of the object to be inspected, even when surface reflections exist.

[0081] The ultrasonic flaw detection device 100A according to the second embodiment will be described in detail below with reference to the drawings.

[0082] <Configuration> The ultrasonic flaw detection apparatus 100A according to the second embodiment differs from the ultrasonic flaw detection apparatus 100 according to the first embodiment in that the generated tomographic data is three-dimensional voxel data and in the analysis method for detecting multi-reflection image MRI, but the other configurations are the same as those of the ultrasonic flaw detection apparatus 100 shown in Fig. 1. Therefore, the following will provide an overview of the generation of tomographic data and the detection method for multi-reflection image MRI in the ultrasonic flaw detection apparatus 100A, and a description of the other configurations will be omitted.

[0083] FIG. 10 is a functional block diagram showing the configuration of each part of the ultrasonic flaw detector 100A.

[0084] (Transmit beam former 103A, reflected signal acquisition unit 104A) The transmit beam former 103A and the reflected signal acquirer 104A include a 3D transmitter 1031A and a 3D receiver 1041A, respectively, instead of the transmitter 1031 and the receiver 1041 in the flaw detection device 100. For each transmission event, the transmit transducer Tx is gradually moved in the column direction while repeatedly transmitting and receiving ultrasonic waves to acquire reflected signals for one frame and generate acoustic line signals. The transmit transducer Tx gradually moves the scan plane for one frame of transmission and reception perpendicular to the array direction of the transducers 101a, thereby repeatedly transmitting and receiving the signals for one frame, thereby generating acoustic line signals for multiple frames required to generate three-dimensional tomographic data. The scan plane may be gradually moved by an operator by gradually moving the probe 101 perpendicular to the array direction of the transducers 101a, or it may be electronically scanned using a 2D probe with transducers arranged in a matrix.

[0085] (Fault data generation unit 105A) The tomographic data generation unit 105A acquires acoustic line signals for multiple frames, and for each frame, performs envelope detection, conversion to brightness values ​​in a logarithmic compression unit 1051A, and coordinate conversion to an orthogonal coordinate system in a coordinate conversion unit 1052A to generate tomographic data for one frame. By repeating this process for multiple frames, three-dimensional tomographic data is generated and output to the multiple reflection area extraction unit 106A.

[0086] (Multiple reflection area extraction unit 106A) The multiple reflection region extraction section 106A includes a specific time region designation section 1061A and a luminance signal extraction section 1062A.

[0087] The specific time region designation unit 1061A extracts, from the acquired three-dimensional 3D tomographic data, a multiple reflection region in which multiple reflection signals can be detected, which corresponds to a depth range deeper than the depth at which a real image of the object to be inspected can be detected, as a data region that can be analyzed. As in the configuration according to the first embodiment, the depth range is specified by designating, as the specific time region, a time region having a predetermined length that is equal to or longer than the time it takes for reflected waves from the inspection target region of the object to arrive. The configuration according to the second embodiment differs from the configuration according to the first embodiment in that the extracted multiple reflection region is three-dimensional voxel data in the X, Y, and Z directions.

[0088] The luminance signal extraction unit 1062A extracts the luminance signal of the multiple reflection region MRA from the 3D tomographic data and outputs it to the detection unit 107A.

[0089] (Detection unit 107A) The detection unit 107 selects analysis target image data OL from the 3D tomographic data of the multiple reflection region MRA, analyzes the extracted spatial frequencies by principal component analysis, and selects one or more principal components including a principal component that reacts to a spatial frequency component of the multiple reflection image MRI corresponding to the defect DL of the object under inspection 300. The detection unit 107A includes an analysis target line identification unit 1071A, a spatial frequency component conversion unit 1072A, a principal component analysis unit 1073A, and a principal component selection unit 1074A.

[0090] 11(a) and 11(b) are diagrams showing an example of a display image drawn on the display unit 111 in an embodiment of the ultrasonic flaw detection device 100A. The operation of the detection unit 107A will be explained using this display image. In Fig. 11(a) and 11(b), the X direction represents the arrangement direction of the transducers 101a, the Y direction represents the direction perpendicular to the arrangement direction of the transducers 101a, and the Z direction represents the depth direction.

[0091] In this embodiment, the analysis object image data OL is planar cross-sectional image data in the planar direction of the object to be inspected, which corresponds to a specific depth ZP. As shown in Fig. 11(a), the analysis object line specifying unit 1071A selects, from the 3D tomographic data of the multiple reflection region MRA, cross-sectional image data in the planar direction of the object to be inspected, which is located at a specific depth ZP, as the analysis object planar cross-section OF. Multiple analysis object planar cross-sections OF may be selected by varying the depth ZP.

[0092] As shown in FIG. 11(b), the spatial frequency component conversion unit 1072A converts the data of the analysis target plane cross section OF into a set of multiple line data in the X or Y direction (in this example, Y line data in the X direction), and extracts spatial frequency components from the set of line data.

[0093] The principal component analysis unit 1073A calculates the first principal component to the M-th principal component for the spatial frequency components, where M is a natural number.

[0094] Here, the principal component analysis can be performed using a known calculation method (for example, Kano Manabu, "Principal Component Analysis," Kyoto University, January 1997). Specifically, when P is the number of spatial frequency components and N is the number of samples on the line data, the data sample {x np}(n=1,2···N,p=1,2···P) is expressed as follows using the matrix X:

[0095]

number

[0096]

number

[0097]

number

[0098]

number

[0099]

number

[0100]

number

[0101] In the principal component analysis 1073A, the Mth principal component selection unit 1074A may, for example, cause a principal component that reacts to the multiple reflection image MRI corresponding to the defect DL (hereinafter, sometimes referred to as a "multiple reflection image corresponding principal component") to appear in the first principal component, and a principal component that does not react to the multiple reflection image MRI corresponding to the defect DL (hereinafter, sometimes referred to as a "multiple reflection image non-corresponding principal component") to appear in the second principal component, but this is not limited to this and may also appear in a principal component other than the first and second.

[0102] Therefore, the principal component selection unit 1074A selects one principal component (multiple reflection image corresponding principal component) from the calculated first to M-th principal components, which includes a multiple reflection image corresponding principal component that responds to the spatial frequency component of the multiple reflection image MRI corresponding to the defect DL of the object to be inspected, and outputs the selected principal component to the output control unit 108A. Alternatively, a plurality of principal components including at least one multiple reflection image corresponding principal component may be selected as the selected principal component. Alternatively, all of the first to M-th principal components may be selected. The principal component to be selected may be set in advance according to the object to be inspected, or may be set arbitrarily.

[0103] (Output control unit 108A) The output control unit 108A includes a reconstruction / output unit 1081A. The reconstruction / output unit 1081A reconstructs the analysis target image data OL for the selected principal component. Specifically, using the principal component scores and coupling coefficients (eigenvectors) obtained by the principal component analysis unit 1073A, the analysis target image data OL (in this example, the analysis target cross section OF) is reconstructed in the direction of the principal component selected by the principal component selection unit 1074A, generating an image and outputting it to the display unit 111.

[0104] Specifically, let P be the number of spatial frequency components, and N be the number of samples on the line data. np The M-th principal component score of} is calculated for each sample x in the P-dimensional space. n (n=1,2,...,N) represents the Mth principal component z M The length of the vector obtained by projecting it onto the axis is n The predicted value x^ reconstructed using only the Mth principal component n is the coupling coefficient w of the Mth principal component M Using

[0105]

number

[0106] 12(a) and 12(b) are diagrams showing an example of a display image drawn on the display unit 111 in an embodiment of the ultrasonic flaw detection system 100A. The display result by the output control unit 108A will be described using this display image. As shown in FIG. 12(a), in an image based on the multi-reflection-image-compatible principal component direction cross-sectional image data, the intensity distribution of the principal components representing the characteristics of the spatial frequency components of the multi-reflection image MRI is displayed on the analysis target plane cross section OF, and the intensity and position of the multi-reflection image MRI are displayed as the intensity distribution of the multi-reflection image-compatible principal component. On the other hand, as shown in FIG. 12(b), in an image based on the multi-reflection-image-uncompatible principal component direction cross-sectional image data, the multi-reflection image MRI is not displayed on the analysis target plane cross section OF.

[0107] This allows the viewer to easily grasp the position of the defect DF in the object under inspection 300 through the displayed image.

[0108] <Action> The operation of the ultrasonic flaw detector 100A configured as above will be described.

[0109] Fig. 13 is a flowchart showing the operation of the ultrasonic flaw detection apparatus 100 A. In Fig. 13, the same processes as those in the operation of the ultrasonic flaw detection apparatus 100 are assigned the same numbers as in Fig. 9, and the description thereof will be omitted.

[0110] In the processing of steps S10 to S90, one frame of tomographic data is generated in the same manner as in FIG.

[0111] Next, the transmission and reception of one frame is repeated while gradually moving the scan plane in the transmission and reception of one frame perpendicular to the arrangement direction of the transducers 101a, thereby generating three-dimensional tomographic data.

[0112] Specifically, first, it is determined whether the position Y of the scan plane in the array direction and perpendicular direction of the transducer 101a for transmission and reception of one frame is the maximum value (step S85A). If it is not the maximum value (step S85: No), Y is incremented (step S86A) and the process returns to step S10, where the scan plane is gradually moved in the array direction and perpendicular direction to perform the processing of steps S10 to S90. If it is the maximum value (step S85: Yes), the generation of three-dimensional tomographic data is completed and the process proceeds to step S90A.

[0113] Next, a multi-reflection region MRA is identified from the three-dimensional tomographic data and a brightness signal is extracted (step S90A), the depth ZP of the plane cross section OF to be analyzed is identified (step S200A), a set of multiple line data (X lines) is obtained (step S210A), the spatial frequency components of the set of line data are extracted, and converted into a spatial frequency data set (step S230A).

[0114] Next, principal component analysis is performed on the spatial frequency components (step S240A), and one or more principal components including a principal component (principal component corresponding to a multiple reflection image) that responds to the spatial frequency component of the multiple reflection image MRI corresponding to the defect DL of the object 300 are selected (step S250A), the data of the plane cross section OF to be analyzed is reconstructed in the direction of the selected principal component (step S260A), image data in the direction of the principal component is generated (step S270A), the image is displayed on the display unit 111 (step S300), and the process is terminated.

[0115] <Small summary> As described above, in the ultrasonic signal analysis device 160 included in the ultrasonic flaw detection device 100A according to the second embodiment, the data to be analyzed is planar cross-sectional OF data in the planar direction of the object to be inspected corresponding to a specific depth, and the detection unit 107A extracts the spatial frequency of the planar cross-sectional OF data, and by principal component analysis, selects one or more principal components including a principal component (principal component corresponding to multiple reflection image) that responds to the spatial frequency component of the multiple reflection image corresponding to the defect in the object to be inspected in the data to be analyzed, and reconstructs the planar cross-sectional OF data in the direction of the selected principal component to generate cross-sectional image data in the direction of the principal component.

[0116] With this configuration, a planar cross-sectional image to be analyzed OF is selected from a multiple reflection region MRA located in a depth range deeper than the inspection target range of the inspection object 300, an intensity distribution in the direction of the principal component that responds to the characteristics of the spatial frequency component of the multiple reflection image MRI corresponding to the defect DF of the inspection object is displayed on the planar cross-sectional image to be analyzed OF, and the intensity and position of the multiple reflection image MRI are displayed as the intensity distribution of the principal component. Therefore, it is possible to accurately detect the position of the defect DF located in a shallow part of the inspection object 300 without being affected by strong regular reflection components such as surface reflection in the real image region RIA corresponding to the inspection target range in the shallow part of the inspection object 300, and to easily grasp the position and state of the defect DF through the displayed image.

[0117] Third Embodiment In the ultrasonic flaw detection device 100A according to the second embodiment and its ultrasonic signal analysis device 160, data of a three-dimensional part corresponding to a specific depth range included in the multiple reflection region MRA is selected as the data to be analyzed, and a multiple reflection image MRI is detected by using principal component analysis of the spatial frequency. In the first and second embodiments, after envelope detection, data converted into brightness values ​​is used as the data to be analyzed.

[0118] In contrast, the ultrasonic flaw detection device 100B according to the third embodiment differs from the second embodiment in that it selects data of a three-dimensional portion corresponding to a specific depth range ZP1 (hereinafter, the depth direction may be referred to as the Z direction) included in the multi-reflection region MRA as the data to be analyzed, and detects a multi-reflection image MRI using principal component analysis of the frequency (a signal in the Z direction that has been frequency-converted). The third embodiment also differs from the second embodiment in that it analyzes data before envelope detection that includes a phase so that it can be subjected to FFT analysis, i.e., data before conversion to brightness values. This method makes it possible to more accurately detect defects included in the specified depth range ZP1 of the inspection target component, even when surface reflections are present.

[0119] The ultrasonic flaw detection device 100B according to the third embodiment will be described below with reference to the drawings.

[0120] <Configuration> The ultrasonic flaw detection apparatus 100B according to the third embodiment differs from the ultrasonic flaw detection apparatus 100A according to the second embodiment in the analysis method for detecting the multi-reflection image MRI, but other configurations are the same as those of the ultrasonic flaw detection apparatus 100A shown in Fig. 10. Therefore, the detection method of the multi-reflection image MRI in the ultrasonic flaw detection apparatus 100A will be outlined below, and a description of the other configurations will be omitted.

[0121] FIG. 14 is a functional block diagram showing the configuration of each part of the ultrasonic flaw detector 100B.

[0122] (Detection unit 107B) The multiple reflection region extraction unit 106A extracts signals of multiple reflection regions MRA from the 3D tomographic data based on the acoustic line signals for multiple frames required to generate three-dimensional tomographic data supplied from the reflection signal acquisition unit 104A, and outputs the signals to the detection unit 107B. In this embodiment, FFT analysis is performed on the acoustic line signals before envelope detection.

[0123] The detection unit 107B selects an analysis target three-dimensional portion OS from the 3D tomographic data of the multiple reflection region MRA, converts signals extracted from the data of the three-dimensional portion OS into frequencies by FFT, and performs principal component analysis to select one or more principal components including a principal component that reacts to a frequency component of the multiple reflection image MRI corresponding to a defect DL in the object under test 300. The detection unit 107B includes an analysis target three-dimensional portion identification unit 1071B, an FFT analysis unit 1072B, a principal component analysis unit 1073B, and a principal component selection unit 1074B.

[0124] Fig. 15 is a schematic diagram for explaining the operation of the ultrasonic flaw detector 100B. In Fig. 15, the X direction represents the arrangement direction of the transducers 101a, the Y direction represents the direction perpendicular to the arrangement direction of the transducers 101a, and the Z direction represents the depth direction.

[0125] In this embodiment, the analysis target data is data of a three-dimensional portion OS corresponding to a specific depth range ZP1. The analysis target three-dimensional portion specifying unit 1071B selects a three-dimensional portion located in the predetermined depth range ZP1 as the analysis target three-dimensional portion OS from the data of the multiple reflection region MRA, as shown in FIG.

[0126] The FFT analysis unit 1072B performs FFT analysis (Fast Fourier Transform; FFT) on the data of the three-dimensional part OS to be analyzed, on the data on the line data in the Z direction passing through the position P(Xn, Yn), extracts frequency components from the line data, and repeats the FFT analysis by changing the position P(Xn, Yn) to extract frequency components from all the data in the three-dimensional part OS to be analyzed.

[0127] The principal component analysis unit 1073B performs principal component analysis on the obtained frequency components, and calculates the first to M-th principal components (M is a natural number).

[0128] The principal component selection unit 1074B selects one principal component (multiple reflection image corresponding principal component) from the calculated first to M-th principal components, which includes a multiple reflection image corresponding principal component that responds to a spatial frequency component of the multiple reflection image MRI corresponding to the defect DL of the object to be inspected, and outputs the selected principal component to the output control unit 108A. Here, multiple principal components including at least one multiple reflection image corresponding principal component may be selected as the selected principal component. Alternatively, all of the first to M-th principal components may be selected. The selected principal component may be set in advance according to the object to be inspected, or may be set arbitrarily.

[0129] (output control unit 108) The output control unit 108 includes a reconstruction and output unit 1081B. The reconstruction and output unit 1081B reconstructs the analysis target image data OL for the selected principal component. Specifically, using the principal component scores and connection coefficients (eigenvectors) obtained by the principal component analysis unit 1073B, the analysis target image data OL (in this example, the analysis target three-dimensional part OS) is reconstructed in the direction of the principal component selected by the principal component selection unit 1074B, generating an image and outputting it to the display unit 111.

[0130] This allows defects within the specified depth range ZP1 of the inspected component to be detected more accurately even when surface reflection is present, and the observer can easily grasp the state of the defects DF within the specified depth range ZP1 of the inspected object 300 through the displayed image.

[0131] <Action> The operation of the ultrasonic flaw detector 100B configured as above will be described.

[0132] Fig. 16 is a flowchart showing the operation of the ultrasonic flaw detection apparatus 100 B. In Fig. 16, the same processes as those in the operation of the ultrasonic flaw detection apparatus 100 A are assigned the same numbers as in Fig. 13, and the description thereof will be omitted.

[0133] In the processing of steps S10 to S60, S85A, and 86A, acoustic line signals for multiple frames required to generate three-dimensional tomographic data are generated, and in step S90A, a multi-reflection region MRA is identified from the generated three-dimensional tomographic data and a signal is extracted.

[0134] Next, the depth range ZP1 of the three-dimensional portion OS to be analyzed is identified (step S300B), a set of multiple line data (X × Y lines) is obtained (step S310B), and the set of line data is subjected to FFT analysis to extract frequency components and converted into a frequency data set (step S330B).

[0135] Next, principal component analysis is performed on the frequency components (step S340B), and one or more principal components are selected (step S350B), including a principal component (principal component corresponding to a multiple reflection image) that responds to the frequency component of the multiple reflection image MRI corresponding to the defect DL of the object 300. The data of the three-dimensional portion OS to be analyzed is reconstructed in the direction of the selected principal component (step S360B), image data in the direction of the principal component is generated (step S370B), and the image is displayed on the display unit 111 (step S400B), thereby completing the process.

[0136] <Small summary> As described above, the ultrasonic signal analysis device 160 included in the ultrasonic flaw detection device 100B according to the third embodiment is configured such that the data to be analyzed is data of a three-dimensional portion corresponding to a specific depth range ZP1, the detection unit 107B performs a fast Fourier transform on the data to be analyzed for each unit data corresponding to the spatial position P(Xn, Yn) to perform frequency conversion, and selects one or more principal components by principal component analysis, including a principal component (principal component corresponding to multiple reflection images) that responds to the frequency component of the multiple reflection image corresponding to the defect DF of the object to be inspected in the data to be analyzed, and the output control unit 108B reconstructs the data to be analyzed in the direction of the selected principal component to generate image data in the direction of the principal component.

[0137] With this configuration, a three-dimensional portion OS to be analyzed is selected from the multiple reflection region MRA located in a depth range deeper than the inspection target range of the inspected object 300, an intensity distribution in the principal component direction that responds to the characteristics of the frequency component of the multiple reflection image MRI corresponding to the defect DF of the inspected object is displayed on the three-dimensional portion OS to be analyzed, and the intensity and position of the multiple reflection image MRI are displayed on the image as an intensity distribution of the principal component corresponding to the multiple reflection image. Therefore, it is possible to accurately detect the position of the defect DF located in the predetermined depth range ZP1 of the inspected object 300 without being affected by strong regular reflection components such as surface reflection in the real image region RIA corresponding to the inspection target range in the shallow part of the inspected object 300, and to easily grasp the state of the defect DF through the displayed image.

[0138] <Ultrasonic signal analysis system 1> An embodiment of the present disclosure is realized as an ultrasonic signal analysis system 1 that collects and analyzes tomographic data from an ultrasonic flaw detector 100 via a network. The ultrasonic signal analysis system 1 according to the embodiment will be described in detail below with reference to the drawings.

[0139] Fig. 1 is a schematic configuration diagram of an ultrasonic signal analysis system 1. As shown in Fig. 17, the ultrasonic signal analysis system 1 is composed of a plurality of ultrasonic flaw detectors 100, a tomographic data storage device 30, and an ultrasonic signal analyzer 160, all connected to a communication network N.

[0140] The communication network N is, for example, the Internet, and multiple ultrasonic flaw detectors 100, tomographic data storage devices 30, and ultrasonic signal analyzers 160 are connected so as to be able to exchange information with one another.

[0141] The ultrasonic flaw detection device 100 acquires tomographic data of the object to be inspected via the connected probe 101 and supplies the data via the communication network N. In the ultrasonic flaw detection system 1, the ultrasonic flaw detection device 100 may be configured to function as a tomographic data generating device that operates only the transmission beam former 103, the multiplexer 102, the reflected signal acquisition unit 104, and the tomographic data generating unit 105, without using the function of the ultrasonic signal analyzer 160 among the functional blocks shown in FIG.

[0142] The tomographic data storage device 30 is, for example, a computer-readable recording medium such as a hard disk, and acquires and stores the tomographic data supplied from the ultrasonic flaw detector 100.

[0143] 1, the ultrasonic signal analysis device 160 includes a multiple reflection region extraction unit 106, a detection unit 107, and an output control unit 108, and reads out the tomographic data stored in the tomographic data storage device 30 or receives the tomographic data from the ultrasonic flaw detection device 100, and detects multiple reflection images MRI in the tomographic data using the analysis method described in any one of the first to third embodiments to detect defects DF in the inspected component, and outputs the detection results to the display unit 111 for display. Furthermore, the ultrasonic signal analysis device 160 outputs the detection results to the ultrasonic signal analysis device 160 via the communication network N to store them.

[0144] With this configuration, the ultrasonic flaw detection system 1 can supply tomographic data acquired by multiple ultrasonic flaw detection devices 100 to an ultrasonic signal analysis device 160 via a communication network N, thereby making it possible to detect defects located in shallow parts of the inspected component.

[0145] <<Variations>> Although the configurations according to the embodiments have been described, the present disclosure is not limited to the above-described embodiments except for the essential characteristic components. For example, the present disclosure also includes forms obtained by various modifications to the embodiments and forms realized by arbitrarily combining the components and functions of each embodiment within the scope of the present invention. Below, modified examples are described as examples of such forms. (1) In the above embodiment, an ultrasonic measurement method has been described in which a defect DL is detected by irradiating an object with 300 ultrasonic beams and detecting a multiple reflection image MRI based on the reflected waves. However, the application of the wave analysis of the present invention is not limited to ultrasonic measurement, and can be widely applied to wave analysis using radio waves, light waves, and electromagnetic waves. (2) In the ultrasonic flaw detection devices 100A and 100B according to the second and third embodiments, the detection unit 107 is configured to analyze the data to be analyzed using principal component analysis and detect the multiple reflection image MRI corresponding to the defect DL in the object 300 to be inspected, but it may also be configured to detect the multiple reflection image MRI from the data to be analyzed using other multivariate analysis methods. (3) In the ultrasonic flaw detection device 100 according to the embodiment, the configurations of the transmission beam former unit 103 and the reflected signal acquisition unit 104 can be changed as appropriate to configurations other than those described in embodiment 1. For example, in embodiment 1, the transmission unit 1031 is configured to set a transmission aperture Tx consisting of a row of transmission transducers that are part of the multiple transducers 101a in the probe 101, and to repeatedly transmit ultrasound waves while gradually moving the transmission aperture Tx in the row direction for each ultrasound transmission, thereby transmitting ultrasound waves from all of the transducers 101a in the probe 101.

[0146] However, it may be configured such that ultrasonic waves are transmitted from all of the transducers 101a in the probe 101. Reflected ultrasonic waves can be received from the entire ultrasonic irradiation region Ax in one ultrasonic wave transmission, without repeating ultrasonic wave transmission. (4) In the embodiment, the calculation target region Bx is a linear region that passes through the center of the row of receiving apertures Rx, is perpendicular to the row of transducers, and has a width of a single transducer.

[0147] However, the calculation target region Bx is not limited to this, and may be set to any region included in the ultrasound irradiation region Ax. For example, it may be a rectangular region in the shape of a strip of a plurality of transducer widths, with a center line passing through the center of the row of receiving transducers and perpendicular to the row of transducers. It may also be an hourglass-shaped region. Furthermore, the calculation target region Bx set for each transmission event may be set so as to overlap in the direction of the row of transducers. The S / N ratio of the generated ultrasound image can be improved by synthesizing acoustic line signals of the overlapping regions using the synthetic aperture method. (5) In the first embodiment, the probe has a configuration in which a plurality of piezoelectric elements are arranged in a one-dimensional direction. However, the configuration of the probe is not limited to this. For example, a two-dimensional array transducer in which a plurality of piezoelectric transducer elements are arranged in a two-dimensional direction, or an oscillating probe in which a plurality of transducer elements arranged in a one-dimensional direction are mechanically oscillated to acquire three-dimensional tomographic data, may be used, and these can be appropriately used depending on the measurement. For example, when a two-dimensional array probe is used, the irradiation position and direction of the transmitted ultrasonic beam can be controlled by individually changing the timing and voltage value of applying voltage to the piezoelectric transducer elements.

[0148] Furthermore, although the ultrasonic flaw detector is configured such that the probe and the display unit are connected from the outside, these may be configured to be provided integrally within the ultrasonic flaw detector. (6) In the embodiment, the receive beamforming process is performed in synchronization with the transmission of ultrasound waves, but this is not limited to this. For example, an aspect of the present disclosure may be applied to a synthetic aperture method, and delay-and-sum may be performed after multiple ultrasound transmissions and receptions for one frame are completed. In addition, any control may be performed for operations other than the calculation of the reception time, not limited to the above-mentioned case. (7) Although one aspect of the present disclosure has been described based on the above embodiment, one aspect of the present disclosure is not limited to the above-mentioned first embodiment, and the following cases are also included in one aspect of the present disclosure.

[0149] For example, one aspect of the present disclosure may be a computer system including a microprocessor and a memory, the memory storing the computer program, and the microprocessor operating in accordance with the computer program. For example, the present disclosure may be a computer system having a computer program for the ultrasound signal processing method of the present invention and operating in accordance with this program (or instructing each connected component to operate).

[0150] The present invention also includes a case where all or part of the ultrasonic flaw detection device or all or part of the ultrasonic signal processing device is configured as a computer system consisting of a microprocessor, recording media such as ROM and RAM, a hard disk unit, etc. The RAM or hard disk unit stores a computer program that achieves the same operations as each of the above devices. Each device achieves its function when the microprocessor operates in accordance with the computer program.

[0151] Furthermore, some or all of the components constituting each of the above devices may be configured as a single system LSI (Large Scale Integration). A system LSI is an ultra-multifunctional LSI manufactured by integrating multiple components on a single chip, and specifically, is a computer system configured to include a microprocessor, ROM, RAM, etc. These may be individually integrated into single chips, or some or all of them may be integrated into a single chip. Note that LSIs are sometimes called ICs, system LSIs, super LSIs, or ultra LSIs depending on the level of integration. The RAM stores a computer program that achieves the same operations as each of the above devices. The system LSI achieves its functions when the microprocessor operates in accordance with the computer program. For example, the present invention also includes a case where the beamforming method of the present invention is stored as a program in an LSI, and this LSI is inserted into a computer to execute a predetermined program (beamforming method).

[0152] The method of integration is not limited to LSI, but may be realized by dedicated circuits or general-purpose processors. It is also possible to use FPGAs (Field Programmable Gate Arrays), which can be programmed after the LSI is manufactured, or reconfigurable processors, which allow the connections and settings of circuit cells inside the LSI to be reconfigured.

[0153] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derived technologies, it is of course possible to integrate functional blocks using that technology.

[0154] Furthermore, some or all of the functions of the ultrasonic flaw detector according to each embodiment 1 may be realized by a processor such as a CPU executing a program. A non-transitory computer-readable recording medium may also be used, on which a program for implementing the flaw detection method or beamforming method of the ultrasonic flaw detector is recorded. The program may be executed by another independent computer system by recording a program or a signal on a recording medium and transferring it. It goes without saying that the program can be distributed via a transmission medium such as the Internet.

[0155] In the ultrasonic flaw detection device according to the above embodiment, the data storage unit, which is a memory device, is configured to be included within the ultrasonic flaw detection device, but the memory device is not limited to this, and a semiconductor memory, a hard disk drive, an optical disk drive, a magnetic memory device, etc. may be configured to be connected to the ultrasonic flaw detection device from the outside.

[0156] The division of functional blocks in the block diagram is an example, and multiple functional blocks may be realized as a single functional block, one functional block may be divided into multiple blocks, or some functions may be moved to another functional block.Furthermore, the functions of multiple functional blocks having similar functions may be processed in parallel or time-shared by a single piece of hardware or software.

[0157] The order in which the steps are performed is merely an example for specifically explaining the present invention, and other orders may be used. Some of the steps may be performed simultaneously (in parallel) with other steps.

[0158] Furthermore, at least some of the functions of the ultrasonic flaw detectors according to the embodiments and their modified examples may be combined. Furthermore, the numbers used above are all examples for specifically explaining the present invention, and the present invention is not limited to the numbers used as examples.

[0159] Furthermore, various modifications of the present embodiment that are within the scope that can be easily conceived by a person skilled in the art are also included in the present invention.

[0160] <Summary> A wave analysis device according to one aspect of the present disclosure is a wave analysis device that detects defects in an object under test based on reflected waves obtained from the object under test, and is characterized by comprising: a multiple reflection region extraction unit that acquires tomographic data generated based on the reflected waves and extracts multiple reflection regions from the tomographic data, and a detection unit that detects multiple reflection images corresponding to defects in the object under test from the extracted multiple reflection regions. The multiple reflection regions may correspond to a depth range in the tomographic data that is deeper than a depth at which a real image of the object under test can be detected, and may be a region where multiple reflection signals can mainly be detected.

[0161] With this configuration, defect detection in the real image region is avoided, and by analyzing signals from the multiple reflection region MRA where multiple reflections are depicted, it is possible to accurately detect defects located in shallow parts of the inspected material even when surface reflections are present.

[0162] In another aspect, in any of the above aspects, the detection unit may be configured to select line data located at a predetermined depth from the multiple reflection area, and if there is a data portion in the line data that exceeds the threshold brightness in a stepped manner over a predetermined length or more, determine and detect that data portion as the multiple reflection image.

[0163] With this simple configuration, it is possible to select an analysis line OL from the multiple reflection region MRA and detect the presence or absence of a multiple reflection image MRI representing a defect DF in the object 300 to be inspected.

[0164] In another aspect, in any of the above aspects, the multiple reflection region extraction section may be configured to extract the multiple reflection region based on a preset parameter.

[0165] In another aspect, in any of the above aspects, the multiple reflection region extraction section may be configured to extract the multiple reflection region by determining signal attenuation or the like.

[0166] In another aspect, in any of the above aspects, the multiple reflection region extraction section may be configured to extract time-series luminance signal data in the multiple reflection region to generate a signal sequence to be analyzed.

[0167] In another aspect, in any of the above aspects, the multiple reflection region extraction section may be configured to calculate an average value of luminance signals in the multiple reflection region to generate a signal sequence to be analyzed.

[0168] In another aspect, in any of the above aspects, the multiple reflection region extraction section may be configured to calculate a maximum value of a luminance signal in the multiple reflection region to generate a signal sequence to be analyzed.

[0169] In another aspect, in any of the above aspects, the detection unit selects planar cross-sectional data in a plane direction of the object to be inspected corresponding to a specific depth from the multiple reflection region, extracts spatial frequencies of the planar cross-sectional data, and selects one or more principal components including a principal component that reacts to a spatial frequency component of a multiple reflection image corresponding to a defect of the object to be inspected in the planar cross-sectional data by principal component analysis. The present invention may further include a reconstruction / output unit that reconstructs the planar cross-sectional data in the selected principal component direction to generate cross-sectional image data in the principal component direction.

[0170] This configuration makes it possible to accurately detect the position of a defect DF located in a shallow portion of the object 300 under inspection without being affected by strong specular reflection components such as surface reflection in the shallow portion of the object 300 under inspection, and to easily grasp the position and state of the defect DF through the displayed image.

[0171] In another aspect, in any of the above aspects, the detection unit selects data of a three-dimensional portion corresponding to a specific depth range from the multiple reflection region, performs a fast Fourier transform on the data of the three-dimensional portion for each unit data corresponding to a spatial position to perform frequency conversion, and selects one or more principal components including a principal component that reacts to a frequency component of a multiple reflection image corresponding to a defect in the object to be inspected in the data of the three-dimensional portion by principal component analysis.Furthermore, the present invention may be configured to include a reconstruction / output unit, and to reconstruct the data of the three-dimensional portion in the direction of the selected principal component to generate image data in the direction of the principal component.

[0172] With this configuration, it is possible to accurately detect the position of the defect DF located in a predetermined depth range ZP1 of the object to be inspected 300 without being affected by strong specular reflection components such as surface reflections in shallow parts of the object to be inspected 300, and it is also possible to easily grasp the state of the defect DF through the 3D display image.

[0173] In another aspect, in any of the above aspects, the output control unit may be configured to generate first principal component direction 3D image data obtained by reconstructing the analysis target image data in the first principal component direction, and second principal component direction 3D image data obtained by reconstructing the analysis target image data in the second principal component direction.

[0174] Furthermore, one aspect of the present disclosure may be a flaw detection device including a wave analysis device according to any of the above aspects, a reflection signal acquisition unit that acquires a reflection signal based on a reflected wave obtained from the test object based on a wave from a probe, and a tomographic data generation unit that generates tomographic data based on the reflection signal and supplies the tomographic data to the multiple reflection area extraction unit.

[0175] With this configuration, it is possible to avoid defect detection in the real image region and to analyze signals from the multiple reflection region where multiple reflections are depicted, thereby realizing a flaw detection device that can accurately detect defects located in shallow parts of the inspection target component even when surface reflections are present. In addition, in any of the above aspects, the tomographic data generation unit may be a flaw detection device that converts the reflection signals into luminance data to generate the tomographic data.

[0176] With this configuration, by performing principal component analysis on the spatial frequency components of the cross-sectional data, a plurality of principal components can be identified, and from among these, multiple reflection image corresponding regions and multiple reflection non-corresponding regions can be identified.

[0177] In any of the above aspects, the tomographic data generating unit may be a flaw detection device that logarithmically compresses the reflected signal and converts it into the brightness data.

[0178] With this configuration, by performing logarithmic compression and then principal component analysis, it is possible to improve the resolution in low brightness areas and make the level of analysis accuracy uniform from low brightness to high brightness.

[0179] Furthermore, one aspect of the present disclosure may be a wave analysis system including the wave analysis device of any of the above aspects and a tomographic data generating device that generates tomographic data based on reflected waves obtained from a test object.

[0180] With this configuration, it is possible to supply tomographic data acquired by multiple flaw detectors to a wave signal analyzer via a communication network N, thereby detecting defects located in shallow portions of the inspected component.

[0181] Furthermore, a wave analysis system according to one aspect of the present disclosure may be a wave analysis system including a wave analysis device according to any of the above aspects, and a tomographic data generation device that generates waves using a probe, acquires reflected signals based on reflected waves obtained from the test object, and generates tomographic data based on the reflected signals.

[0182] With this configuration, it is possible to supply tomographic data acquired by multiple flaw detectors to a wave signal analyzer via a communication network N, thereby detecting defects located in shallow portions of the inspected component.

[0183] Furthermore, one aspect of the present disclosure may be a wave analysis method for detecting defects in an object under test based on reflected waves obtained from the object under test, the wave analysis method comprising: acquiring tomographic data generated based on the reflected waves; extracting from the tomographic data a multiple reflection region in which multiple reflection signals can be detected, the multiple reflection region corresponding to a depth range deeper than a depth at which a real image of the object under test can be detected, and detecting a multiple reflection image corresponding to the defect in the object under test from the extracted multiple reflection region.

[0184] With this configuration, it is possible to realize a wave signal analysis method that can acquire tomographic data obtained by a flaw detector and detect defects located in shallow portions of a test object component.

[0185] Furthermore, one aspect of the present disclosure may be a program that causes a computer to perform wave analysis processing to detect defects in an object under test based on reflected waves obtained from the object under test, wherein the wave analysis processing may be a program that acquires tomographic data generated based on the reflected waves, extracts from the tomographic data a multiple reflection region that corresponds to a depth range deeper than a depth at which a real image of the object under test can be detected and in which multiple reflection signals can primarily be detected, and detects a multiple reflection image corresponding to the defect in the object under test from the extracted multiple reflection region.

[0186] With this configuration, it is possible to realize a wave signal analysis processing program that can acquire tomographic data obtained by a flaw detector and detect defects located in shallow portions of a component to be inspected.

[0187] <Additional Information> The embodiments described above each illustrate a preferred specific example of the present invention. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in embodiment 1 are merely examples and are not intended to limit the present invention. Furthermore, among the components in embodiment 1, steps that are not recited in the independent claims that represent the highest concept of the present invention are described as optional components that constitute more preferred embodiments.

[0188] In addition, to facilitate understanding of the invention, the scales of the components in the drawings given in each of the above-mentioned embodiments 1 may differ from the actual scales. Furthermore, the present invention is not limited to the descriptions of the above-mentioned embodiments, and can be modified as appropriate within the scope of the gist of the present invention.

[0189] Furthermore, in an ultrasonic flaw detector, there are also circuit components, lead wires, and other components on the board, but various embodiments of electrical wiring and electrical circuits can be implemented based on common knowledge in the technical field, and since they are not directly related to the explanation of the present invention, their explanation is omitted. Note that the figures shown above are schematic diagrams and are not necessarily strict illustrations. [Industrial Applicability]

[0190] The wave analysis device, wave analysis system, flaw detection device, wave analysis method, and program according to the present disclosure can be widely used in non-destructive testing for defect detection using a probe equipped with an array of transducers. [Explanation of symbols]

[0191] 1000 Ultrasonic Flaw Detector Set (Flaw Detector Set) 100, 100A, 100B Ultrasonic flaw detection device (flaw detection device) 150 Ultrasonic signal processing device 160 Ultrasonic signal analysis device (wave analysis device) 101 Probe (ultrasonic probe) 101a oscillator 102 Multiplexer section 103, 103A Transmit beam former unit 1031, 1031A transmitter 104, 104A Reflected signal acquisition section 105, 105A Fault data generation unit 106, 106A Multiple reflection area extraction part 107, 107A, 107B detection unit 108, 108A, 108B Output control section 109 Control Unit 110 Data storage unit 111 Display section 200 cabinets 211 Retaining member 300 Test subject 1. Ultrasonic signal analysis system (wave analysis system)

Claims

1. A wave analysis device for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, a multiple reflection region extraction unit that acquires tomographic data generated based on the reflected waves and extracts multiple reflection regions from the tomographic data; a detection unit that detects a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, The multiple reflection region extraction unit specifies a time region having a predetermined length, which is equal to or longer than the time required for a reflected wave from an inspection target range of the object to be inspected, as a specific time region, and identifies, in the tomographic data, a region where image data exists based on a reflected signal obtained in the specific time region, as the multiple reflection region. Wave analysis device.

2. The multiple reflection region corresponds to a depth range in the tomographic data that is deeper than a depth at which a real image of the object to be inspected can be detected, and is a region where multiple reflection signals can be detected. The wave analysis device according to claim 1 .

3. The detection unit selects line data located at a predetermined depth from the multiple reflection region, and if there is a data portion in the line data that exceeds a threshold brightness in a stepped manner over a predetermined length or more, determines and detects the data portion as the multiple reflection image. The wave analysis device according to claim 1 .

4. The multiple reflection region extraction unit extracts the multiple reflection region based on preset parameters. The wave analysis device according to any one of claims 1 to 3.

5. The multiple reflection region extraction unit extracts the multiple reflection region by determining signal attenuation, etc. The wave analysis device according to any one of claims 1 to 4.

6. The multiple reflection region extraction unit extracts time-series luminance data in the multiple reflection region and generates a signal sequence to be analyzed. The wave analysis device according to any one of claims 1 to 5.

7. The multiple reflection region extraction unit calculates an average value of luminance signals in the multiple reflection region to generate a signal sequence to be analyzed. The wave analysis device according to any one of claims 1 to 6.

8. The multiple reflection region extraction unit calculates the maximum value of the luminance signal in the multiple reflection region to generate a signal sequence to be analyzed. The wave analysis device according to any one of claims 1 to 6.

9. A wave analysis device for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, a multiple reflection region extraction unit that acquires tomographic data generated based on the reflected waves and extracts multiple reflection regions from the tomographic data; a detection unit that detects a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, the detection unit selects planar cross-sectional data in a planar direction of the object to be inspected, the planar cross-sectional data corresponding to a specific depth from the multiple reflection region; A spatial frequency of the planar cross-sectional data is extracted, and one or more principal components including a principal component that responds to a spatial frequency component of a multiple reflection image corresponding to a defect of the object to be inspected in the planar cross-sectional data are selected by principal component analysis. Wave analysis device.

10. Further, a reconstruction and output unit is provided which reconstructs the planar cross-sectional data in a selected principal component direction and generates cross-sectional image data in the principal component direction. The wave analysis device according to claim 9.

11. A wave analysis device for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, a multiple reflection region extraction unit that acquires tomographic data generated based on the reflected waves and extracts multiple reflection regions from the tomographic data; a detection unit that detects a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, the detection unit selects data of a three-dimensional portion corresponding to a specific depth range from the multiple reflection region, and performs a fast Fourier transform on the data of the three-dimensional portion for each unit data corresponding to a spatial position to perform a frequency conversion; By principal component analysis, one or more principal components including a principal component that responds to a frequency component of a multiple reflection image corresponding to a defect of the object to be inspected in the data of the three-dimensional portion are selected. Wave analysis device.

12. Further, a reconstruction and output unit is provided which reconstructs the data of the three-dimensional part in the selected principal component direction and generates image data in the principal component direction. The wave analysis device according to claim 11.

13. A wave analysis device according to any one of claims 1 to 12, a reflected signal acquiring unit that acquires a reflected signal based on a reflected wave obtained from the test object based on a wave motion from the probe; a tomographic data generating unit that generates tomographic data based on the reflected signals and supplies the tomographic data to the multiple reflection region extracting unit; Flaw detection equipment.

14. The tomographic data generating unit converts the reflected signal into brightness data to generate the tomographic data. The flaw detection device according to claim 13.

15. The tomographic data generating unit converts the reflected signal into the brightness data by logarithmically compressing the reflected signal. The flaw detection device according to claim 14.

16. A wave analysis device according to any one of claims 1 to 12, and a tomographic data generating device that generates tomographic data based on the reflected waves obtained from the object to be inspected. Wave analysis system.

17. A wave analysis device according to any one of claims 1 to 12, a tomographic data generating device that generates a wave using a probe, acquires a reflected signal based on the reflected wave obtained from the object to be inspected, and generates tomographic data based on the reflected signal. Wave analysis system.

18. A wave analysis method for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, comprising: Acquire tomographic data generated based on the reflected waves, extracting from the tomographic data a multiple reflection region that corresponds to a depth range deeper than a depth at which a real image of the object can be detected and in which multiple reflection signals can be mainly detected; detecting a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, In the step of extracting the multiple reflection region, a time region having a predetermined length that is equal to or longer than the time required for a reflected wave from an inspection target range of the object to be inspected is designated as a specific time region, and an area in the tomographic data where image data based on a reflected signal obtained in the specific time region exists is identified as the multiple reflection region. Wave analysis method.

19. A program for causing a computer to perform a wave analysis process for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, The wave analysis process includes: Acquire tomographic data generated based on the reflected waves, extracting from the tomographic data a multiple reflection region that corresponds to a depth range deeper than a depth at which a real image of the object can be detected and in which multiple reflection signals can be mainly detected; detecting a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, In the step of extracting the multiple reflection region, a time region having a predetermined length that is equal to or longer than the time required for a reflected wave from an inspection target range of the object to be inspected is designated as a specific time region, and an area in the tomographic data where image data based on a reflected signal obtained in the specific time region exists is identified as the multiple reflection region. program.

20. A wave analysis method for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, comprising: Acquire tomographic data generated based on the reflected waves, extracting from the tomographic data a multiple reflection region that corresponds to a depth range deeper than a depth at which a real image of the object can be detected and in which multiple reflection signals can be mainly detected; detecting a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, In the step of detecting the multiple reflection image, a planar cross-sectional data in a planar direction of the object to be inspected, the planar cross-sectional data corresponding to a specific depth, is selected from the multiple reflection region; A spatial frequency of the planar cross-sectional data is extracted, and one or more principal components including a principal component that responds to a spatial frequency component of a multiple reflection image corresponding to a defect of the object to be inspected in the planar cross-sectional data are selected by principal component analysis. Wave analysis method.

21. A wave analysis method for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, comprising: Acquire tomographic data generated based on the reflected waves, extracting from the tomographic data a multiple reflection region that corresponds to a depth range deeper than a depth at which a real image of the object can be detected and in which multiple reflection signals can be mainly detected; detecting a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, In the step of detecting the multiple reflection image, data of a three-dimensional portion corresponding to a specific depth range is selected from the multiple reflection region, and the data of the three-dimensional portion is frequency-converted by fast Fourier transform for each unit data corresponding to a spatial position; By principal component analysis, one or more principal components including a principal component that responds to a frequency component of a multiple reflection image corresponding to a defect of the object to be inspected in the data of the three-dimensional portion are selected. Wave analysis method.

22. A program for causing a computer to perform wave analysis processing for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, comprising: The wave analysis process includes: Acquire tomographic data generated based on the reflected waves, extracting from the tomographic data a multiple reflection region that corresponds to a depth range deeper than a depth at which a real image of the object can be detected and in which multiple reflection signals can be mainly detected; detecting a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, In the step of detecting the multiple reflection image, a planar cross-sectional data in a planar direction of the object to be inspected, the planar cross-sectional data corresponding to a specific depth, is selected from the multiple reflection region; A spatial frequency of the planar cross-sectional data is extracted, and one or more principal components including a principal component that responds to a spatial frequency component of a multiple reflection image corresponding to a defect of the object to be inspected in the planar cross-sectional data are selected by principal component analysis. program.

23. A program for causing a computer to perform wave analysis processing for detecting defects in an object to be inspected based on a reflected wave obtained from the object to be inspected, comprising: The wave analysis process includes: Acquire tomographic data generated based on the reflected waves, extracting from the tomographic data a multiple reflection region that corresponds to a depth range deeper than a depth at which a real image of the object can be detected and in which multiple reflection signals can be mainly detected; detecting a multiple reflection image corresponding to a defect of the object to be inspected from the extracted multiple reflection region, In the step of detecting the multiple reflection image, data of a three-dimensional portion corresponding to a specific depth range is selected from the multiple reflection region, and the data of the three-dimensional portion is frequency-converted by fast Fourier transform for each unit data corresponding to a spatial position; By principal component analysis, one or more principal components including a principal component that responds to a frequency component of a multiple reflection image corresponding to a defect of the object to be inspected in the data of the three-dimensional portion are selected. program.

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