JP7233646B2 - ULTRASOUND INSPECTION METHOD, ULTRASOUND INSPECTION APPARATUS AND PROGRAM - Google Patents

Description

The present invention relates to an ultrasonic inspection method, an ultrasonic inspection apparatus, and a program.

2. Description of the Related Art Conventionally, techniques related to inspection methods for scanning an inspection object with ultrasonic signals and performing various inspections on the inspection object are known. For example, in Patent Document 1, a full matrix capture (FMC: FULL Matrix Capture) scan using a plurality of probes acquires data obtained by scanning a conduit as an inspection object with an ultrasonic signal, and the acquired data is Techniques are disclosed for processing using a waveform synthesis process such as the Total Focusing Method (TFM) to delineate the conduit in the scan range and inspect the thickness of the conduit.

Japanese Patent No. 6224594

The method described in Patent Document 1 is a method for inspecting the wall thickness of a conduit, and the position of the surface of the conduit (the surface near and far from the probe for ultrasonic inspection) is measured by the above-described FMC / TFM. Identified through data collection and processing. However, in order to identify the surface position of the conduit, multiple processes such as Canny edge detection, edge dilation, thinning, trimming of misrecognized pixels, and horizontal edge approximation are performed. It takes a long time.

The present invention has been made in view of the above, and an object of the present invention is to reduce the computational load of processing in an inspection method for performing an ultrasonic inspection on an inspection object.

In order to solve the above-described problems and achieve the object, the present invention provides an ultrasonic inspection method for scanning and inspecting an object to be inspected with ultrasonic waves, wherein the above-mentioned Data collected by scanning the inspection object with ultrasonic signals using a plurality of probes that transmit ultrasonic signals to the inspection object and receive ultrasonic signals reflected from the inspection object. and a data synthesizing step of processing and synthesizing the ultrasonic signal data acquired in the data acquiring step, wherein the data synthesizing step is based on the ultrasonic signal data acquired in the data acquiring step. a primary drawing step of drawing an image including the surface of the inspection object in a region including a plurality of pixels partitioned in a grid pattern; A shape for specifying the position of the extracted pixel as the surface shape of the inspection object by extracting pixels having the maximum pixel intensity from among those arranged along the direction orthogonal to the extending direction of the surface of the inspection object. and a specific step.

With this configuration, the surface shape of the inspection object can be specified simply by creating an image including the surface of the inspection object instead of the entire inspection object and extracting the pixels exhibiting the maximum pixel intensity from the created image. Therefore, complicated processing is not required to identify the surface shape of the inspection object.

Moreover, it is preferable that the primary drawing step draws the image in a predetermined range that includes the surface of the inspection object.

With this configuration, it is possible to create an image including the surface by excluding ultrasonic signals reflected from a position different from the surface of the inspection object (i.e., inside the inspection object), thereby improving calculation accuracy. It becomes possible.

Further, it is preferable that the shape identifying step extracts pixels having the pixel intensity equal to or higher than a predetermined threshold among the pixels having the maximum pixel intensity.

With this configuration, for the surface of the inspection object where the pixel intensity is less than the predetermined threshold, the ultrasonic signals are reflected outside the range of the plurality of probes and do not enter the inside of the inspection object. can be assumed to exist and this surface location can be excluded from the determination of the surface shape. As a result, when the specified surface shape is used for subsequent processing, the processing can be executed without using unnecessary surface shape position data, so that the calculation load can be further reduced. .

Further, the data synthesizing step calculates a position where the propagation time of the ultrasonic signal from the probe to the arbitrary pixel is the minimum among the surface shapes specified in the shape specifying step, and the calculated A path calculation step in which a path passing through the position of the surface shape is a propagation path of the ultrasonic signal; and for the data of the ultrasonic signal collected in the data collection step, the amplitude is calculated based on the propagation path calculated in the path calculation step. It is preferable to further comprise an amplitude value synthesizing step of synthesizing the amplitude values by matching the timing and the pixels at which the values are increasing.

With this configuration, the reflected waveform of the ultrasonic signal generated by synthesizing the amplitude value by matching the timing and position at which the ultrasonic signal transmitted from each probe was reflected inside the inspection object (the amplitude value increased). You can get results. Thereby, the position of the internal defect of the inspection object can be detected. In addition, by using the data group of the ultrasonic signals acquired in the data collection step, it is possible to specify the surface shape of the inspection object and then perform continuous processing, so that real-time inspection can be improved. It becomes possible.

Further, along the surface shape specified in the shape specifying step, the ultrasonic signal transmission/reception surface formed along the arrangement direction of the plurality of probes is curved, and the data collection step and the primary drawing step are performed. and performing the shape identification step again.

With this configuration, since the transmitting/receiving surfaces of the plurality of probes are curved along the surface shape of the inspection object specified in the shape specifying step, more ultrasonic signals are generated in the probes arranged at the ends. of reflected waves can be captured. As a result, in the shape specifying step that is executed again, it is possible to specify the shape at the end of the surface shape with higher accuracy.

In the shape identifying step, the pixel intensity is set to a continuous value along a direction perpendicular to the extension direction, and a pixel having the maximum pixel intensity is determined based on the value obtained by applying a differentiation filter to the continuous value. It is preferable that the differential filter has a higher sensitivity at the edges of the uneven surface formed by the surface than at the central portion.

With this configuration, it is possible to accurately identify the pixel having the maximum pixel intensity at the edge of the surface shape based on the value obtained by applying a differential filter with higher sensitivity to the continuous value of the pixel intensity. As a result, it is possible to specify the surface shape of the inspection object with higher accuracy.

In addition, the primary drawing step is performed, for each pixel, on the basis of the coordinates of the probe that transmitted/received the strongest ultrasonic signal and the transmission/reception time of the strongest ultrasonic signal. estimating an angle of inclination, calculating, for each pixel, an angle of incidence and an angle of reflection of an ultrasonic signal with respect to the surface based on the estimated angle of inclination; It is preferable to render the image by applying enhancement correction to the data.

With this configuration, among the ultrasonic signals transmitted from one probe and received by the other probe, ultrasonic signals whose angles of incidence and reflection with respect to the surface of the object to be inspected are similar, that is, strong ultrasonic signals can be specified. Then, an image can be created by applying enhancement correction to the data of the identified strong ultrasonic signal. As a result, the surface of the object to be inspected can be drawn with higher accuracy in the primary drawing step, and the surface shape can be specified with higher accuracy in the subsequent shape specifying step.

In order to solve the above-described problems and achieve the object, the present invention provides an ultrasonic inspection apparatus for scanning and inspecting an object to be inspected with ultrasonic waves, wherein the above-mentioned a plurality of probes for transmitting ultrasonic signals to an object to be inspected and receiving ultrasonic signals reflected from the object to be inspected; and an arithmetic processing unit for executing a data synthesis processing for processing and synthesizing the data of the ultrasonic signals acquired in the data acquisition processing, wherein the arithmetic processing unit comprises the a primary drawing process of drawing an image including the surface of the inspection object in a region containing a plurality of pixels partitioned in a grid pattern based on ultrasonic signal data collected in the data collection process; In the drawn image, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object, and the extracted pixel as the surface shape of the object to be inspected.

With this configuration, the surface shape of the inspection object can be specified simply by creating an image including the surface of the inspection object instead of the entire inspection object and extracting the pixels exhibiting the maximum pixel intensity from the created image. Therefore, complicated processing is not required to identify the surface shape of the inspection object.

Further, the arithmetic processing unit calculates a position where the propagation time of the ultrasonic signal from the probe to the arbitrary pixel is the minimum among the surface shapes specified in the shape specifying process, and the calculated A path calculation process in which the path passing through the position of the surface shape is the propagation path of the ultrasonic signal; It is preferable to further execute an amplitude value synthesizing process for synthesizing the amplitude values by matching the timing and the pixels at which the values are increased.

With this configuration, the reflected waveform of the ultrasonic signal generated by synthesizing the amplitude value by matching the timing and position at which the ultrasonic signal transmitted from each probe was reflected inside the inspection object (the amplitude value increased). You can get results. Thereby, the position of the internal defect of the inspection object can be detected. In addition, by using the data group of the ultrasonic signals acquired in the data collection step, it is possible to specify the surface shape of the inspection object and then perform continuous processing, so that real-time inspection can be improved. It becomes possible.

Further, the arithmetic processing unit can improve the calculation speed by using a GPGPU (General-Purpose Computing On Graphics Processing Unit). At least one GPU is required, but multiple GPUs can be used in parallel.

Further, the arithmetic processing unit performs the data collection process, the primary drawing process, and the shape identification process in a state in which the transmission/reception surfaces of the plurality of probes are curved along the surface shape identified in the shape identification process. Preferably, the process is performed again.

With this configuration, since the transmitting/receiving surfaces of the plurality of probes are curved along the surface shape of the inspection object specified by the shape specifying process, more ultrasonic signals are generated in the probes arranged at the ends. of reflected waves can be captured. As a result, it becomes possible to specify the shape at the edge of the surface shape with higher accuracy in the shape specifying process that is executed again.

In addition, the shape identification process sets the pixel intensity to a continuous value along a direction orthogonal to the extending direction, and determines a pixel having the maximum pixel intensity based on a value obtained by applying a differential filter to the continuous value. It is preferable that the differential filter has a higher sensitivity at the edges of the uneven surface formed by the surface than at the central portion.

With this configuration, it is possible to accurately identify the pixel having the maximum pixel intensity at the edge of the surface shape based on the value obtained by applying a differential filter with higher sensitivity to the continuous value of the pixel intensity. As a result, it is possible to specify the surface shape of the inspection object with higher accuracy.

In addition, the primary rendering process is performed on the surface of the inspection object based on the coordinates of the probe that transmitted/received the strongest ultrasonic signal and the transmission/reception time of the strongest ultrasonic signal for each pixel. estimating an angle of inclination, calculating, for each pixel, an angle of incidence and an angle of reflection of an ultrasonic signal with respect to the surface based on the estimated angle of inclination; It is preferable to render the image by applying enhancement correction to the data.

With this configuration, among the ultrasonic signals transmitted from one probe and received by the other probe, ultrasonic signals whose angles of incidence and reflection with respect to the surface of the object to be inspected are similar, that is, strong ultrasonic signals can be specified. Then, an image can be created by applying enhancement correction to the data of the identified strong ultrasonic signal. As a result, the surface of the object to be inspected can be drawn with higher accuracy in the primary drawing step, and the surface shape can be specified with higher accuracy in the subsequent shape specifying step.

In order to solve the above-described problems and achieve the object, the present invention transmits an ultrasonic signal to an object to be inspected through a medium for propagating the ultrasonic wave signal, and ultrasonic waves reflected from the object to be inspected A data collection step of collecting data obtained by scanning the inspection object with ultrasonic signals using a plurality of probes that receive signals; and processing and synthesizing the data of the ultrasonic signals collected in the data collection step. and a data synthesizing step, wherein the data synthesizing step divides the surface of the inspection object into an area including a plurality of pixels partitioned in a grid pattern based on the data of the ultrasonic signals acquired in the data acquiring step. and a primary rendering step of rendering an image containing and a shape specifying step of extracting a pixel having the maximum pixel intensity and specifying the position of the extracted pixel as the surface shape of the inspection object.

With this configuration, the surface shape of the inspection object can be specified simply by creating an image including the surface of the inspection object instead of the entire inspection object and extracting the pixels exhibiting the maximum pixel intensity from the created image. Therefore, complicated processing is not required to identify the surface shape of the inspection object.

FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic inspection apparatus according to an embodiment. FIG. 2 is an explanatory diagram schematically showing a portion of a calculation area for performing data processing by TFM in the second arithmetic processing unit. FIG. 3 is a flow chart showing the processing procedure of the ultrasonic inspection method according to the embodiment. FIG. 4 is an explanatory diagram showing an example of an image including the surface of piping created in the primary rendering step. FIG. 5 is an explanatory diagram showing an example of plotting pixel intensities. FIG. 6 is an explanatory diagram showing the coordinates of each pixel with the maximum pixel intensity. FIG. 7 is an explanatory diagram showing an example of propagation paths of ultrasonic signals from an arbitrary probe to an arbitrary pixel. FIG. 8 is an explanatory diagram showing an example of waveforms of ultrasonic signals traveling from an arbitrary probe to an arbitrary pixel. FIG. 9 is an explanatory diagram showing the outline of the ultrasonic inspection apparatus according to the second embodiment. FIG. 10 is a flow chart showing an example of a main part of the processing procedure of the ultrasonic inspection method according to the second embodiment. FIG. 11 is a flow chart showing an example of the main part of the processing procedure of the ultrasonic examination method according to the fourth embodiment. FIG. 12 is an explanatory diagram showing an example of a probe that has transmitted and received an ultrasonic signal with the highest intensity. FIG. 13 is an explanatory diagram showing an example of incident angles and reflection angles of ultrasonic signals. FIG. 14 is an explanatory diagram schematically showing a main part of an ultrasonic inspection apparatus and an ultrasonic inspection method according to the fifth embodiment. FIG. 15 is an explanatory diagram schematically showing a main part of an ultrasonic inspection apparatus according to the sixth embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an ultrasonic inspection method, an ultrasonic inspection apparatus, and a program according to the present invention will be described in detail below with reference to the drawings. In addition, this invention is not limited by this embodiment.

[First embodiment]
FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic inspection apparatus according to the first embodiment. In the first embodiment, the inspection object is pipes 1 connected to each other at welds 2 (see FIG. 2). The welded portion 2 has a surplus portion that protrudes from the surface 1a of the pipe 1 (see FIG. 2). The “surface 1 a of the pipe 1 ” also includes the surface of the welded portion 2 . An ultrasonic inspection apparatus 100 according to the first embodiment is an inspection apparatus (flaw detection apparatus) for detecting defects in a welded portion 2 having an excess build-up portion with a pipe 1 as an inspection object.

The ultrasonic inspection apparatus 100 includes a flaw detector 10, a calculation section 20, and an operation/display section 30, as shown in FIG. The flaw detector 10 has a linear array probe 11 , a pulser 12 , a receiver 13 , a data storage section 14 and a control element switching section 15 .

The linear array probe 11 has a plurality (N) of probes 110 (see FIG. 2). In the first embodiment, multiple probes 110 are arranged in a linear array. Note that the arrangement configuration of the plurality of probes 110 is not limited to this. In the following description, the i-th (i is an integer from 1 to N) probe 110 is referred to as probe 110i. Each probe 110 is connected to a pulser 12 as a transmitter and a receiver 13 as a receiver. A medium capable of propagating the ultrasonic signal S is filled between the probe 110 and the pipe 1 as an object to be inspected. Each probe 110 transmits an ultrasonic signal S transmitted from the pulsar 12 to the welded portion 2 of the pipe 1 as an object to be inspected via a medium, as indicated by the white arrow in FIG. Each probe 110 also receives the ultrasonic signal S reflected from the welded portion 2 of the pipe 1 via the medium and sends it to the receiver 13 . The ultrasonic signal S sent to the receiver 13 is stored in the data storage section 14 . The control element switching unit 15 switches the probe 110 to transmit the ultrasonic signal S from the pulser 12 among the plurality of probes 110 in accordance with an instruction from the control unit 21 of the calculation unit 20 to be described later.

The medium that fills between the probe 110 and the pipe 1 as an object to be inspected may be any medium as long as it can propagate ultrasonic waves. As the medium, for example, ultrasonically transparent gel, water, or the like can be used. For example, when an ultrasonic wave transmitting gel is used as the medium, by pressing a pocket of the ultrasonic wave transmitting gel against the surface of the pipe 1 with an appropriate force, even if the welded portion 2 has a complicated shape, the ultrasonic wave can be generated. The sound-transmitting gel deforms according to the shape of the welded portion 2 . Thereby, the space between the pipe 1 and the linear array probe 11 can be filled with the medium without any gap. Here, for simplification of explanation, it is assumed that the space between the probe 110 and the pipe 1 is filled with a single medium. Thereby, the ultrasonic signal S is propagated through the medium between the linear array probe 11 and the pipe 1 .

The calculator 20 is an arithmetic processing device provided separately from the flaw detector 10 and connected to the flaw detector 10 in the first embodiment. The calculation unit 20 is, for example, an externally connected personal computer. Note that the calculator 20 may be provided integrally with the flaw detector 10 . The calculation unit 20 has a control unit 21 , a storage unit 22 , a first arithmetic processing unit 23 and a second arithmetic processing unit 24 .

The control unit 21 is an arithmetic processing device including, for example, a CPU (Central Processing Unit). The control unit 21 is connected to the control element switching unit 15 of the flaw detector 10, the storage unit 22, the second arithmetic processing unit 24, and the inspection condition setting unit 32 of the operation/display unit 30, which will be described later. The control unit 21 loads a program stored in the storage unit 22 into memory and executes instructions included in the program. More specifically, the control unit 21 acquires information on inspection conditions set by the user from the inspection condition setting unit 32 . Based on the acquired inspection condition information, the control unit 21 controls the control element switching unit 15 to sequentially transmit ultrasonic signals from each probe 110 of the linear array probe 11 to the pipe 1 as an inspection object. S is transmitted, and the data of the ultrasonic signal S reflected from the pipe 1 is collected. When the data collection by the FMC is finished, the control section 21 commands the second arithmetic processing section 24 to execute various kinds of processing of the collected data.

In the first embodiment, a so-called full matrix capture (hereinafter referred to as "FMC") method is used for data acquisition of the ultrasonic signal S. FIG. FMC is a procedure in which all the probes (transducers) 110 of one linear array probe 11 receive the ultrasonic signal S emitted from the probes (transducers) 110 and reflected from the inspection target. is repeated for the number of elements to acquire transmission/reception data for all the probes (transducers) 110 in one linear array probe 11 . More specifically, the controller 21 causes one of the plurality of probes 110 of the linear array probe 11 to transmit an ultrasonic signal S to the pipe 1 . The ultrasonic signal S reflected from the pipe 1 is received by all the probes 110 and stored in the data storage section 14 via the receiver 13 . At this time, if the number of probes 110 of the linear array probe 11 is N, the data storage unit 14 stores N data about the ultrasonic signal S reflected from the pipe 1 . Next, the control unit 21 causes the probe 110 different from (for example, adjacent to) the probe 110 that generated the ultrasonic signal S at the previous timing to similarly transmit the ultrasonic signal S. As a result, N pieces of data are newly stored in the data storage unit 14 for the ultrasonic signal S reflected from the pipe 1 . This process is repeated until ultrasonic signals S are emitted from all of the N probes 110 . As a result, the data storage unit 14 stores N×N matrix type data about the ultrasonic signal S reflected from the pipe 1 . The N×N matrix type data about this ultrasonic signal S is the data obtained by scanning the pipe 1 with the ultrasonic signal S. As shown in FIG.

The storage unit 22 stores data (programs) required for various processes in the ultrasonic inspection apparatus 100 . The storage unit 22 is, for example, a semiconductor memory device such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, or a storage device such as a hard disk or an optical disk. The storage unit 22 is connected to the data storage unit 14 , first arithmetic processing unit 23 and second arithmetic processing unit 24 of the flaw detector 10 . The storage unit 22 receives data of the N×N ultrasonic signals S collected by the FMC described above from the data storage unit 14 and stores the received data. The storage unit 22 transmits the stored data of the ultrasonic signal S to the first arithmetic processing unit 23 and the second arithmetic processing unit 24 in response to their requests.

The first arithmetic processing unit 23 is an arithmetic processing device configured by, for example, a CPU. The first arithmetic processing section 23 is connected to the storage section 22 , the second arithmetic processing section 24 , the calculation condition setting section 33 of the operation/display section 30 , and the calculation result display section 31 . The first arithmetic processing unit 23 loads a program stored in the storage unit 22 into memory and executes instructions included in the program. The first arithmetic processing unit 23 acquires information on calculation conditions set based on the inspection conditions from the calculation condition setting unit 33 . The first arithmetic processing unit 23 transmits the acquired calculation conditions to the second arithmetic processing unit 24 . Also, the first arithmetic processing unit 23 transmits the result calculated by the second arithmetic processing unit 24 to the calculation result display unit 31 .

The second arithmetic processing unit 24 is an arithmetic processing device configured by a GPU (Graphics Processing Unit). The second arithmetic processing section 24 is connected to the control section 21 , the storage section 22 and the first arithmetic processing section 23 . In the first embodiment, the second arithmetic processing unit 24 also performs processing other than image creation processing using a so-called GPGPU. Thereby, the calculation speed can be improved. At least one GPU is required, but multiple GPUs can be used in parallel. The second arithmetic processing unit 24 receives the data of the N×N ultrasonic signals S collected by the FMC described above from the storage unit 22 . The second arithmetic processing unit 24, according to the command from the control unit 21 and the information of the calculation condition from the first arithmetic processing unit 23, the data of the N × N ultrasonic signals S, that is, the data obtained by scanning the pipe 1 are processed and synthesized by a total focus method (hereinafter referred to as “TFM”), and based on the synthesis result, a calculation result is created in which the inside of the pipe 1 is drawn. TFM is a variety of techniques for analyzing ultrasound signal S data collected by FMC and synthesizing the ultrasound signal S. FIG. Details of the TFM used in the ultrasonic inspection method according to the first embodiment will be described later.

FIG. 2 is an explanatory diagram schematically showing a portion of a calculation area for performing data processing by TFM in the second arithmetic processing unit. In the following description including FIG. 2, the calculation area is shown in two dimensions for simplification, but the actual calculation is performed in a three-dimensional area. Moreover, although FIG. 2 shows an example in which the plurality of probes 110 of the linear array probe 11 are arranged in a row, the arrangement configuration of the plurality of probes 110 is not limited to this. As shown in FIG. 2, the second arithmetic processing unit 24 calculates N×N ultrasonic signals S collected by the FMC for each pixel P in a computational area including a plurality of pixels P partitioned in a grid pattern. are synthesized by the TFM. In the first embodiment, the plurality of pixels P are arranged in a direction e1, which is the extending direction of the surface 1a of the pipe 1 to be inspected (horizontal direction in FIG. 2), and perpendicular to the extending direction of the surface 1a of the pipe 1. It is partitioned in a grid pattern along the direction e2, which is the direction (vertical direction in FIG. 2). It should be noted that the plurality of pixels P shown in FIG. 2 indicate a part of the calculation area, and in fact, not only the internal area of the pipe 1 but also the area between the linear array probe 11 and the pipe 1 is similar. is a computational region divided into a plurality of pixels P in . In the first embodiment, one core is assigned to each unit voxel (not shown) including a plurality of pixels P in the second arithmetic processing unit 24 . The second arithmetic processing unit 24 performs calculation processing by TFM in parallel for each unit voxel, and creates a calculation result of drawing the inside of the pipe 1 . The second arithmetic processing unit 24 transmits the created calculation result to the first arithmetic processing unit 23 .

The operation/display unit 30 is a device that has both a display function for displaying test results and an input operation function as a user interface. For example, a touch panel display can be used as the operation/display unit 30 . The operation/display unit 30 is provided separately from the flaw detector 10 and connected to the calculation unit 20 in the first embodiment. Note that the operation/display unit 30 may be provided integrally with the flaw detector 10 . Further, the operation/display unit 30 is not limited to a touch panel type display, and may be provided separately with a display function for displaying test results and an operation function as a user interface.

The operation/display unit 30 has a calculation result display unit 31, an inspection condition setting unit 32, and a calculation condition setting unit 33, as shown in FIG. The calculation result display section 31 is connected to the first arithmetic processing section 23 of the calculation section 20 . The calculation result display unit 31 displays the calculation result calculated by the second calculation processing unit 24 and received from the first calculation processing unit 23, that is, the drawing result of the inside of the pipe 1 to the user. The inspection condition setting unit 32 is a user interface for the user to set inspection conditions. The inspection conditions include, for example, information such as the arrangement configuration of the plurality of probes 110 of the linear array probe 11 and the type of medium. The inspection conditions also include information such as, for example, that the object to be inspected is the welded portion 2 of the pipe 1, the size (thickness) of the pipe 1, and the type of material forming the pipe 1. The calculation condition setting unit 33 sets calculation conditions based on the inspection conditions input by the user, and transmits the calculation conditions to the first arithmetic processing unit 23 of the calculation unit 20 . The calculation conditions are various conditions required when the second arithmetic processing unit 24 performs arithmetic processing according to the information of the inspection conditions. The calculation conditions include, for example, information on a calculation area partially schematically shown by a plurality of pixels P in FIG.

Next, the processing procedure of the ultrasonic inspection method according to the first embodiment will be described. FIG. 3 is a flow chart showing the processing procedure of the ultrasonic inspection method according to the first embodiment. The processing procedure shown in FIG. 3 is performed by executing a program stored in the storage unit 22 by the control unit 21 , the first arithmetic processing unit 23 and the second arithmetic processing unit 24 of the calculation unit 20 . The processing procedure shown in FIG. 3 is executed with the flaw detector 10 positioned at a predetermined position on the welded portion of the pipe 1 .

The calculation unit 20 executes a data collection step (data collection process) by the control unit 21 as step S1. The data acquisition step is a step of scanning the pipe 1 as an object to be inspected with an ultrasonic signal by the FMC. As described above, the control unit 21 performs a procedure for all the probes 110 to receive the ultrasonic signal emitted from one probe 110 and reflected from the inspection object. . As a result, the data storage unit 14 stores N×N matrix-type data of the ultrasonic signals reflected from the pipe 1 , that is, the data obtained by scanning the pipe 1 .

Next, the calculation unit 20 executes the processing from step S2 to step S5 as a data synthesizing step of processing and synthesizing the data of the ultrasonic signal S acquired in the data acquiring step by TFM. The processing from step S<b>2 to step S<b>5 is executed by the second arithmetic processing section 24 according to an instruction from the control section 21 of the calculation section 20 . Further, the processing from step S2 to step S5 is executed in parallel for each unit voxel assigned by the second arithmetic processing section 24, as described above.

The second arithmetic processing unit 24 executes a primary drawing step (primary drawing process) as step S2. The primary drawing step is a step of drawing an image M including the surface 1a of the pipe 1 in a region partitioned by a plurality of pixels P based on the data of the ultrasonic signal S collected in the data collecting step. FIG. 4 is an explanatory diagram showing an example of an image including the surface of piping created in the primary drawing step. The image M illustrated in FIG. 4 targets the range surrounded by the dashed line in FIG. The image M exemplified in FIG. 4 is obtained by synthesizing the amplitude values of the ultrasonic signal S acquired by the FMC in the data acquisition step by aligning the timing at which the amplitude value increases and the position of the pixel P, and producing the synthesized amplitude value. It can be drawn by computing the associated intensity values and mapping them onto the computational domain. This processing can be performed using well-known TFM techniques. Also, the primary drawing step can be executed using techniques other than the TFM method. The primary drawing step can also use a method of synthesizing received echoes in the frequency domain by, for example, the Inverse Scattering Imaging Method (ISIM). Furthermore, the primary drawing step is not limited to the waveform resynthesis processing by TFM, and the surface shape can also be drawn by the phased array method or the vertical UT method. The second arithmetic processing unit 24 creates an image M in a predetermined range H that defines the surface position of the pipe 1 in advance, as illustrated as a range sandwiched by two-dot chain lines in FIG. 2 . The predetermined range H is, for example, the time when the ultrasonic signal S propagates the distance between the linear array probe 11 and the surface position of the pipe 1 through the medium A filled between the probe 110 and the pipe 1. determined based on As a result, of the ultrasonic signals S collected by FMC, only those propagated through the medium A and reflected from the surface position of the pipe 1 are subjected to synthesis processing to create an image M including the surface 1a of the pipe 1. can be done.

The second arithmetic processing unit 24 executes a shape identification step (shape identification processing) as step S3. In the shape identification step, in the image M drawn in the primary drawing step, among the plurality of pixels P, those arranged along the direction e2 orthogonal to the extending direction of the surface 1a of the pipe 1 have the maximum pixel intensity. This is a step of extracting pixels P and specifying the positions of the extracted pixels P as the surface shape of the pipe 1 . Among the plurality of pixels P, those arranged along the direction e2 mean the pixels P included in the columns along the direction e2. Note that the plurality of pixels P arranged along the direction e2 may be composed of a plurality of pixels P arranged in two or more rows along the direction e2 instead of the plurality of pixels P arranged in a row along the direction e2. .

The shape identification step will be described in detail with reference to FIGS. 5 and 6. FIG. FIG. 5 is an explanatory diagram showing an example of plotting pixel intensities, and FIG. 6 is an explanatory diagram showing the coordinates of each pixel with the maximum pixel intensity. In FIG. 5, columns P1, P2, P3, P4, P5, P6, and P7 of pixels P along direction e2 are arranged along direction e1, and pixel intensities of pixels P contained in columns P1 to P7 are plotted. ing. As shown in the figure, by connecting the plotted points of the pixel intensity of each pixel P for each of the columns P1 to P7, it can be represented like a waveform. Based on the amplitude values of this waveform, the pixel P with the highest pixel intensity can be extracted for each column P1-P7. The second arithmetic processing unit 24 extracts, for each column of pixels P, the pixel intensity of all the pixels P included in the image M shown in FIG. As a result, as shown in FIG. 6, the extracted pixels P become point cloud data arranged along the direction e1. The second arithmetic processing unit 24 identifies the point cloud data shown in FIG. 6 as the surface shape of the pipe 1 (sets it as the surface coordinates of the pipe 1).

Here, in the shape identification step, when extracting the pixel P having the maximum pixel intensity in the above-described procedure, the second arithmetic processing unit 24 extracts only the pixel P having the pixel intensity equal to or higher than a predetermined threshold. The predetermined threshold value is a value that can be estimated that the ultrasonic signal S reflected by the surface 1a of the pipe 1 is mainly reflected outside the range of the plurality of probes 110 of the linear array probe 11. predetermined. When the ultrasonic signal S is reflected mainly outside the range of the plurality of probes 110 of the linear array probe 11 , it can be estimated that the ultrasonic signal S is not incident inside the pipe 1 . Therefore, the position of the pixel P with the pixel intensity below the predetermined threshold does not need to be treated as the surface shape (surface coordinates) of the pipe 1 in subsequent processing, and this pixel P can be excluded.

After specifying the surface shape of the pipe 1 in the processing from step S1 to step S3, the second arithmetic processing unit 24 executes a route calculation step (route calculation processing) as step S4. The path calculation step calculates the position where the propagation time of the ultrasonic signal S from the probe 110 to an arbitrary pixel P is the minimum among the surface shapes identified in the shape identification step, and calculates the position of the calculated surface shape. This is the step of setting the path through which the ultrasound signal S passes as the propagation path.

Details of the route calculation step will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 is an explanatory diagram showing an example of a propagation path of an ultrasonic signal from an arbitrary probe to an arbitrary pixel, and FIG. FIG. 4 is an explanatory diagram showing an example of waveforms of signals; In FIG. 7, when the coordinate axes are directions e1 and e2, the coordinates of an arbitrary (i-th) probe 110i are ( _Zi1 , _Zi2 ), and the coordinates of an arbitrary pixel _Pk are ( _Xk1 , _Xk2) . ) and the surface coordinates of the pipe 1 through which the ultrasonic signal S passes are (Y _ki1 , Y _ki2 ). Also, here, the inside of the pipe 1 shall be treated as a "medium B". Also, FIG. 8 shows the waveform of the ultrasonic signal S when there is a defect inside the welded portion 2 at the position of an arbitrary pixel _Pk .

As shown in FIGS. 7 and 8, the ultrasonic signal S emitted from the probe 110i is refracted at the surface 1a of the pipe 1, which is the boundary between the medium A and the medium B (time t1 in FIG. 8), It enters the interior of the welded portion 2 (medium B) and reaches the position of the pixel _Pk (time t2 in FIG. 8). At this time, the propagation time T for the ultrasonic signal S to reach the position of the pixel _Pk from the probe 110i can be calculated by the following equation (1). "Ca" in Equation (1) is the speed of sound in medium A, and "Cb" is the speed of sound in medium B (pipe 1).

T=Sqrt((Z _i1 −Y _ki1 ) ² +(Z _i2 −Y _ki2 ) ² )/Ca+Sqrt((Y _ki1 −X _k1 ) ² +(Y _ki2 −X _k2 ) ² )/Cb (1)

Now, the coordinates (Z _i1 , Z _i2 ) of an arbitrary probe 110i and the coordinates (X _k1 , X _k2 ) of an arbitrary pixel P _k are predetermined values. is only the surface coordinates (Y _ki1 , Y _ki2 ) of the pipe 1 . Here, it can be considered that the ultrasonic signal S passes through the shortest propagation path from the probe 110i to the position of the pixel _Pk . This is based on Fermat's principle. Therefore, among the surface coordinates of the pipe 1 identified in the shape identification step, the coordinate at which the propagation time T calculated by the formula (1) is the minimum is determined by the ultrasonic signal S from the medium A to the inside of the pipe 1 (medium B). can be the position of the incident on the As a result, the coordinates (Z _i1 , Z _i2 ) of an arbitrary probe 110i, the coordinates (X _k1 , X _k2 ) of an arbitrary pixel P _k and the surface coordinates (Y _ki1 , Y _ki2 ) of the pipe 1 are all determined. Therefore, the transmission path of the ultrasonic signal S can be determined. The second arithmetic processing unit 24 calculates all propagation paths until the ultrasonic signal S transmitted from each probe 110 reaches each pixel P included in the calculation area according to the above-described propagation path determination procedure. do.

The second arithmetic processing unit 24 executes an amplitude value synthesizing step (amplitude value synthesizing process) as step S5. The amplitude value synthesizing step synthesizes the amplitude values of the data of the ultrasonic signal S collected in the data collecting step by matching the timing and pixels at which the amplitude values increase based on the propagation path calculated in the path calculating step. It is a step to That is, if the propagation path of the ultrasonic signal S to each pixel P is determined in the path calculation step, the propagation time T of the ultrasonic signal S to each pixel P is also determined based on Equation (1). Therefore, in the data of each ultrasonic signal S collected by FMC in the data collection step, the timing at which the amplitude value increases (time t2 in the example shown in FIG. 8) and the propagation time calculated by equation (1) By matching with T, it can be determined at which pixel P the ultrasonic signal S was reflected. Therefore, the second arithmetic processing unit 24 synthesizes the amplitude values of the ultrasonic signals S having the same propagation time T for all the data of the ultrasonic signals S collected by the FMC in the data collecting step at the corresponding pixels P. .

The second arithmetic processing unit 24 executes a drawing step as step S6. The drawing step is a step of calculating the calculation result of drawing the inside of the pipe 1 by calculating intensity values related to the amplitude values synthesized in the amplitude value synthesizing step and mapping them in the calculation area. The second arithmetic processing unit 24 transmits the calculation result of drawing the inside of the pipe 1 to the calculation result display unit 31 of the operation/display unit 30 via the first arithmetic processing unit 23 . Thereby, the user can refer to the calculation result displayed on the calculation result display section 31 .

As described above, in the ultrasonic inspection method, ultrasonic inspection apparatus 100, and program according to the first embodiment, an image M including the surface 1a is created instead of the entire pipe 1 as an inspection object. The surface shape of the pipe 1 can be specified only by extracting the pixel P showing the maximum pixel intensity from the image M. Therefore, complicated processing is not required to identify the surface shape of the pipe 1 . Therefore, according to the ultrasonic inspection method, the ultrasonic inspection apparatus 100, and the program according to the first embodiment, it is possible to reduce the computational load of processing in the inspection method for ultrasonically inspecting the inspection object by FMC/TFM. can.

In the primary drawing step (primary drawing process, step S2), the image M is drawn in a predetermined range H that includes the surface 1a of the pipe 1. As shown in FIG.

With this configuration, the image M including the surface 1a can be created by excluding the ultrasonic signal S reflected from a position different from the surface 1a of the pipe 1 (that is, the inside of the pipe 1), thereby improving the calculation accuracy. becomes possible.

In addition, the shape identification step (shape identification process; step S3) extracts pixels P having pixel intensities equal to or greater than a predetermined threshold among the pixels P having the maximum pixel intensities.

With this configuration, for the surface 1a of the inspection object whose pixel intensity is less than the predetermined threshold, the ultrasonic signal S was reflected outside the range of the plurality of probes 110 and did not enter the pipe 1. position and exclude this surface position from determining the surface shape. As a result, when the specified surface shape is used for subsequent processing, the processing can be executed without using unnecessary surface shape position data, so that the calculation load can be further reduced. .

Further, in the data synthesizing step (steps S2 to S5), among the surface shapes specified in the shape specifying step, the position where the propagation time T of the ultrasonic signal S from the probe 110 to an arbitrary pixel P is the minimum. The path calculation step (path calculation process, step S4) of calculating and setting the path passing through the calculated position of the surface shape as the propagation path of the ultrasonic signal S, and the data of the ultrasonic signal collected in the data collection step, It further comprises an amplitude value synthesizing step (amplitude synthesizing process, step S5) of synthesizing the amplitude values by matching the timing and the pixels at which the amplitude values increase based on the propagation path calculated in the path calculating step.

With this configuration, the timing and position at which the ultrasonic signal S transmitted from each probe 110 is reflected inside the pipe 1 (increased amplitude value) are matched and the amplitude value is synthesized. Reflection of the ultrasonic signal S Waveform results can be obtained. Thereby, the position of the internal defect of the piping 1 can be detected. In addition, by using the data group of the ultrasonic signal S acquired in the data collection step, the surface shape of the pipe 1 can be specified and then the process can be performed continuously, so that the real-time performance of the inspection can be improved. It becomes possible.

Also, the second arithmetic processing unit 24 includes a plurality of cores assigned to each unit voxel including at least one pixel P, and uses the plurality of cores to perform shape identification processing in parallel for each unit voxel. In addition, the second arithmetic processing unit 24 uses a plurality of cores to perform path calculation processing and amplitude value synthesis processing in parallel for each unit voxel.

This configuration can improve the calculation speed. Note that the shape identification process, the path calculation process, and the amplitude value synthesis process may be processed by a single core.

In the first embodiment, a single medium is filled between the probe 110 and the pipe 1, but the configuration of the medium is not limited to this. Any medium can be used as long as the ultrasonic signal S can propagate. The medium may be air.

Also, the medium is not limited to a single medium, and may include a plurality of mediums. When a plurality of media are used, each processing of the data synthesizing steps (steps S2 to S5) may be executed in correspondence with the type and arrangement position of each medium.

Alternatively, the space between the linear array probe 11 and the inspection object may be filled with water by making the inspection object full water depth or local water depth, and the ultrasonic signal S may be propagated using water as a medium.

In the first embodiment, a defect inside the pipe 1 is detected, but the application target of the ultrasonic inspection method and the ultrasonic inspection apparatus 100 according to the first embodiment is not limited to this. For example, the ultrasonic inspection method and ultrasonic inspection apparatus 100 according to the first embodiment can also be applied when measuring the thickness of the pipe 1 . That is, if the shape of the surface (outer surface) 1a of the pipe 1 is specified in the shape specifying step, and the ultrasonic signal reflected from the inner surface of the pipe 1 is subjected to the same synthesis processing in the subsequent processing, the surface (outer surface) 1a of the pipe 1 ( An image drawn from the outer surface 1a to the inner surface can be created. As a result, the flaw detection inspection of the welded portion 2 of the pipe 1 and the wall thickness measurement of the pipe 1 can be performed based on the data collected in one data collection step. As a result, the time required for the inspection can be shortened, and the stop time for inspection of the plant facility in which the pipe 1 is arranged can be shortened.

Moreover, the inspection object is not limited to the pipe 1, and may be any object as long as the flaw detector 10 can be placed thereon and can be scanned by an ultrasonic signal.

[Second embodiment]
Next, an ultrasonic inspection apparatus and an ultrasonic inspection method according to a second embodiment will be described. Here, as described above, in the image M drawn in the primary drawing step, connecting points plotting the pixel intensity of each pixel P for each of the columns P1 to P7 of the pixels P along the direction e2 yields a waveform like can be represented as a continuous value (see, for example, FIG. 5). The continuous value of the pixel intensity is measured at the edge or start point 2S (see FIG. 9) of the uneven surface 2A (see FIG. 9) formed by the weld 2 of the pipe 1 compared to its center point 2C (see FIG. 9). and near the end point 2E (see FIG. 9), the wave height tends to decrease. This is because, in the data acquisition step of step S1 in FIG. This is due to the fact that it is less than near the point 2C. As a result, there is a possibility that many noise components will be detected in the vicinity of the edges of the uneven surface 2A, and there is a possibility that the surface shape in the vicinity of the edges of the uneven surface 2A cannot be specified with high accuracy.

In the second embodiment, the surface shape including the end portions of the uneven surface 2A is specified with high accuracy by the apparatus configuration and processing described below. FIG. 9 is an explanatory diagram showing the outline of the ultrasonic inspection apparatus according to the second embodiment. An ultrasonic inspection apparatus 200 according to the second embodiment includes a linear array probe 41 instead of the linear array probe 11 of the ultrasonic inspection apparatus 100 . Since other configurations of the ultrasonic inspection apparatus 200 are the same as those of the ultrasonic inspection apparatus 100, the same reference numerals are assigned to the same configurations, and the description thereof is omitted.

The linear array probe 41 has a plurality (N) of probes 110 connected to the pulser 12 and the receiver 13 in the same manner as the linear array probe 11 . A transmitting/receiving surface 110A for transmitting/receiving ultrasonic signals S formed by the plurality of probes 110 forms a part of the lower end surface of the linear array probe 41 . As shown in FIG. 9, the linear array probe 41 is a flexible array probe that can be freely bent in the arrangement direction of the plurality of probes 110 (horizontal direction in FIG. 9). In other words, the transmitting/receiving surface 110A formed by the plurality of probes 110 is freely bendable in the arrangement direction. In the example shown in FIG. 9, the linear array probe 41 is formed in a size that covers the uneven surface 2A formed by the welded portion 2 of the pipe 1 in a curved state. 9, the linear array probe 41 is given a predetermined pressing force along the arrangement direction, so that the transmitting/receiving surface 110A formed by the plurality of probes 110 is curved.

Next, the essential part of the ultrasonic inspection method according to the second embodiment will be described with reference to FIGS. 9 and 10. FIG. FIG. 10 is a flow chart showing an example of a main part of the processing procedure of the ultrasonic inspection method according to the second embodiment. More specifically, FIG. 10 shows an example of a processing procedure for correcting the coordinates of each probe 110 when the linear array probe 41 is curved. The processing procedure shown in FIG. 10 is executed between the shape identification step and the route calculation step shown in FIG.

When the second arithmetic processing unit 24 of the calculation unit 20 identifies the surface shape of the pipe 1 by executing the data collection step of step S1 to the shape identification step of step S3 shown in FIG. 3, in step S11, the identified surface shape , the coordinate points of the start point 2S, the end point 2E, and the center point 2C of the uneven surface 2A are specified. A start point 2S, an end point 2E, and a center point 2C of the uneven surface 2A are specified from the coordinates of each pixel P of the specified surface shape.

Next, the second arithmetic processing unit 24 calculates the curvature radius _Rs of the uneven surface 2A as step S12. The radius of curvature _Rs of the uneven surface 2A is calculated by Newton's method using the following equations (2) and (3). "d1" in the formula (2) is the chord length of the uneven surface 2A, that is, the linear distance from the start point 2S to the end point 2E. Further, "h" in the formula (3) is the arrow height at the center point 2C of the uneven surface 2A, and is calculated from the difference from the coordinate in the vertical direction of the surface 1a other than the uneven surface 2A. Note that "θ" in formulas (2) and (3) is the central angle of the uneven surface 2A. Once the values of "d1" and "h" are determined, the radius of curvature _Rs and "θ" are also calculated as approximate values by Newton's method.

d1= _2.Rs.sin (θ/2) (2)
h=R _s ·(1-cos(θ/2) (3)

Next, the second arithmetic processing unit 24 calculates the radius of curvature _Re of the transmitting/receiving surfaces 110A of the plurality of probes 110 as step S13. Here, the radius of curvature R _e is a value as a command value for bending the transmitting/receiving surfaces 110A of the plurality of probes 110 in accordance with the uneven surface 2A. The radius of curvature R _e as the command value is calculated according to the following equation (4). "G" in the formula (4) is the distance (gap) from the surface 1a other than the uneven surface 2A of the pipe 1 to the lower end of the transmission/reception surface 110A, as shown in FIG.

R _e = R _s + G (4)

Next, the second arithmetic processing unit 24 calculates the value of the pressing amount X of the transmission/reception surface 110A as step S14. The amount of pressing X is the amount of pressing the linear array probe 41 along the arrangement direction in order to bend the transmitting/receiving surfaces 110A of the plurality of probes 110 with the radius of curvature _Re , and is calculated according to the following equation (5). be done. “L” in Equation (5) is the arc length of the transmitting/receiving surface 110A, ie, the initial length, and “d2” in Equation (5) is the chord length of the transmitting/receiving surface 110A, ie, the length of the probe 110 at the end. Straight line distance. "d2" can be calculated according to equation (6).

X=L−d2 (5)
d2=2·R _e ·sin (L/R _e ) (6)

When the pressing amount X is determined in this manner, a pressing force is applied to the linear array probe 41 so that the linear array probe 41 is bent by the pressing amount X. FIG. As a result, as shown in FIG. 9, the linear array probe 41 is curved, and the transmitting/receiving surface 110A formed by the plurality of probes 110 is curved with a radius of curvature Re, resulting in a shape along the uneven surface 2A. The application of the pressing force to the linear array probe 41 may be performed by a drive device (not shown) controlled by the controller 21 .

Next, the second arithmetic processing unit 24 corrects the coordinates of the plurality of probes 110 as step S15. That is, the coordinates of each probe 110 in a state in which the transmission/reception surface 110A of the plurality of probes 110 is curved with the radius of curvature _Re are calculated based on the value of the pressing amount X, and the calculated coordinates are set to the coordinates of

Then, as steps S16 to S18, the second arithmetic processing unit 24 again executes the data collection step of step S1, the primary drawing step of step S2, and the shape identification step of step S3 shown in FIG. As a result, as shown in FIG. 9, the ultrasonic signal S reflected near the end of the uneven surface 2A is transmitted by the plurality of probes 110 whose transmitting/receiving surface 110A is curved with a radius of curvature R _e along the uneven surface 2A. , can be captured better. That is, in the data collection step of step S16 that is executed again, more ultrasonic signals S reflected near the edges of the uneven surface 2A can be captured. As a result, in the primary drawing step of step S17 and the shape specifying step of step S18 which are executed again, the surface shape of the pipe 1 including the vicinity of the end portion of the uneven surface 2A can be specified with higher accuracy.

In the second embodiment, the process shown in FIG. 10 is executed after the data collection step of step S1 in FIG. 3 and the shape identification step of step S3 are performed once. However, based on the data of the ultrasonic signal S collected in the data collection step of step S1, the coordinates of the surface shape of the pipe 1 are specified by a known TFM process, and using the specified coordinates of the surface shape, FIG. may be performed.

[Third Embodiment]
Next, an ultrasonic inspection apparatus and an ultrasonic inspection method according to the third embodiment will be described. In the ultrasonic inspection method according to the third embodiment, the processing described below is executed in the shape identification step shown in FIG. In the third embodiment, the configuration of the apparatus is the same as that of the ultrasonic inspection apparatus 100 shown in FIG. 1 except that the processing content in the calculation unit 20 is different, so the description of the configuration of the apparatus will be omitted.

In the third embodiment, the second arithmetic processing unit 24 of the calculation unit 20 extracts the pixel P having the maximum pixel intensity using a differential filter in the shape identification step S3. That is, as described above, in the image M drawn in the primary drawing step, the pixel intensity of each pixel P is can be expressed as a continuous value like a waveform by connecting the plotted points (see FIG. 5). In the third embodiment, the pixel P with the maximum pixel intensity is extracted based on the value obtained by applying a differential filter to the continuous values. That is, by applying a differentiation filter, it is possible to obtain the amount of change for the continuous values of the waveform illustrated in FIG. can. Therefore, a predetermined differential filter is applied to the continuous values of the waveform illustrated in FIG. 5, and the pixel P with the largest change amount is identified as the pixel P with the highest pixel intensity.

Here, in the third embodiment, a different differential filter is used for each position on the uneven surface 2A (see FIG. 9) to specify the pixel P with the highest pixel intensity. As described above, the continuous values of pixel intensity tend to have smaller wave heights near the start point 2S and the end point 2E, which are ends, compared to the central point 2C of the uneven surface 2A. Therefore, it is preferable to use a differential filter with higher sensitivity in the vicinity of the start point 2S and the end point 2E, which are the ends. In the third embodiment, the primary differential filters shown in Equations 1 and 2 are used in the vicinity of the central point 2C of the uneven surface 2A. Equation 1 is the Prewitt filter and Equation 2 is the Sobel filter. Either the Prewitt filter or the Sobel filter may be used near the center point 2C. On the other hand, near the start point 2S and the end point 2E, which are the ends of the uneven surface 2A, the secondary differential filter shown in Equation 3 is used. The secondary differential filter of Equation 3 is a Laplacian filter.

In this way, at the start point 2S and the end point 2E, which are the ends of the uneven surface 2A, compared to the central point 2C, by using a second-order differential filter with higher sensitivity to the amount of change, the wave height of the continuous value of the pixel intensity is Even if is small, the pixel P with the highest pixel intensity can be extracted with high accuracy. Therefore, in the shape identifying step of step S3 shown in FIG. 3, it is possible to more accurately identify the surface shape of the pipe 1 including the end (edge portion) of the uneven surface 2A.

[Fourth embodiment]
Next, an ultrasonic inspection apparatus and an ultrasonic inspection method according to a fourth embodiment will be described. In the ultrasonic inspection method according to the fourth embodiment, the processing described below is executed in the primary drawing step shown in FIG. In the fourth embodiment, the configuration of the ultrasonic inspection apparatus 100 shown in FIG. 1 is the same as that of the ultrasonic inspection apparatus 100 shown in FIG. FIG. 11 is a flow chart showing an example of the main part of the processing procedure of the ultrasonic examination method according to the fourth embodiment.

The second arithmetic processing unit 24 of the calculation unit 20, as step S21, the probe 110 that received the strongest ultrasonic signal S among the data of the ultrasonic signal S collected in the data collecting step of FIG. Then, the coordinates of the probe 110 that transmitted the ultrasonic signal S with the highest intensity are specified. FIG. 12 is an explanatory diagram showing an example of a probe that has transmitted and received an ultrasonic signal with the highest intensity. As shown in the figure, it is assumed that the strongest ultrasonic signal S reflected by an arbitrary pixel on the uneven surface 2A of the pipe 1 is transmitted by the probe 111 and received by the probe 114 . At this time, the second arithmetic processing unit 24 identifies the coordinates of the probes 111 and 114 . Note that the strongest ultrasonic signal S reflected by an arbitrary pixel on the uneven surface 2A is the data of the ultrasonic signal S collected in the data acquisition step, for example, as shown at time t1 in FIG. It is possible to extract and specify the one whose amplitude value is increased by being reflected at . Similarly, the coordinates of the probe 110 that received the strongest ultrasonic signal S and the probe 110 that transmitted the strongest ultrasonic signal S are specified for all pixels on the uneven surface 2A. do.

Next, in step S22, the second arithmetic processing unit 24 calculates (estimates) the virtual inclination angle φ of the uneven surface 2A for each arbitrary pixel based on the coordinates of the probe 110 specified in step S21. . The virtual tilt angle φ is the tilt angle with respect to the extension direction, and is calculated based on the coordinates of the probe 110 that transmitted and received the strongest ultrasonic signal S and the time required to transmit and receive the strongest ultrasonic signal S. be done. The second arithmetic processing unit 24 calculates the virtual tilt angle φ by the same method for all the pixels on the uneven surface 2A. In other words, the shape of the uneven surface 2A is specified by the virtual inclination angle φ.

Next, in step S23, the second arithmetic processing unit 24 transmits the ultrasonic signal S transmitted from each probe 110, reflected by the uneven surface 2A, and received by the other probe 110. Calculate the angle β. FIG. 13 is an explanatory diagram showing an example of incident angles and reflection angles of ultrasonic signals. Since the virtual inclination angle φ of the uneven surface 2A is calculated in step S22, the virtual inclined surface 3 inclined at the virtual inclination angle φ with respect to the extending direction is defined. As shown in FIG. 13, the angles formed by the ultrasonic signal S with respect to the orthogonal plane 4 perpendicular to the virtual inclined plane 3 are the incident angle α and the reflection angle β. The second arithmetic processing unit 24 calculates the incident angle α and the reflection angle β of the ultrasonic signal S reflected by all the pixels on the uneven surface 2A.

Next, in step S24, the second arithmetic processing unit 24 identifies, for all the data of the ultrasonic signals S, the ultrasonic signals S whose incident angle α and reflection angle β approximate to each other calculated in step S23. The ultrasonic signal S whose incident angle α and reflection angle β are close to each other means that the incident angle α and reflection angle β are the closest among the ultrasonic signals S reflected by each pixel on the uneven surface 2A. means Alternatively, the condition may be that the difference between the incident angle α and the reflection angle β is equal to or less than a predetermined value. In this way, the ultrasonic signal S whose incident angle α and reflection angle β are similar generally tends to be the strongest ultrasonic signal S reflected by the uneven surface 2A. In step S24, not only the ultrasonic signal S having the closest values for the incident angle α and the reflection angle β, but also the ultrasonic signals S having the second, third and subsequent closest values are identified. can be anything.

In step S25, the second arithmetic processing unit 24 performs enhancement correction on the ultrasonic signal S in which the incident angle α and the reflection angle β identified in step S24 approximate each other. That is, for the ultrasonic signal S identified as having an incident angle α and a reflection angle β similar to each other, a corrected peak value is calculated by multiplying the peak value (amplitude value) by a predetermined correction coefficient k.

In step S26, the second arithmetic processing unit 24 generates an image M (See FIG. 4). That is, for all the data including the ultrasound signal S subjected to enhancement correction, the amplitude values are synthesized together with the timing at which the amplitude value increases and the position of the pixel, and the intensity value associated with the synthesized amplitude value is calculated and mapped to the computational domain.

In addition to or instead of the above enhancement correction, the process of step S25 is performed to detect ultrasonic waves other than the ultrasonic signal S having similar incident angles α and reflection angles β identified in step S24. It may be a process of excluding the signal S from the data group. Accordingly, in step S26, the image M may be drawn using only the ultrasonic signal S whose incident angle α and reflection angle β are similar.

As described above, in the fourth embodiment, among the ultrasonic signals S transmitted from one probe 110 and received by another probe 110, the incident angle with respect to the surface 1a (uneven surface 2A) of the pipe 1 An ultrasonic signal S with similar α and reflection angle β, ie a strong ultrasonic signal S, can be identified. Then, the image M can be created by applying enhancement correction to the data of the identified strong ultrasonic signal S. FIG. As a result, in the primary drawing step, the surface 1a (uneven surface 2A) of the pipe 1 including the vicinity of the end portion can be drawn with higher accuracy, and in the subsequent shape identification step, the surface shape can be identified with higher accuracy. It becomes possible.

After the processing from step S21 to step S24 shown in FIG. 11 is performed to specify the ultrasonic signal S whose incident angle α and reflection angle β are similar, only the probe 110 that transmits and receives the ultrasonic signal S may be used to execute the data collection step of step S1 shown in FIG.

[Fifth embodiment]
Next, an ultrasonic inspection apparatus and an ultrasonic inspection method according to a fifth embodiment will be described. FIG. 14 is an explanatory diagram schematically showing a main part of an ultrasonic inspection apparatus and an ultrasonic inspection method according to the fifth embodiment. In the ultrasonic inspection apparatus 500 according to the fifth embodiment, as shown, the linear array probe 11 is movable along all directions of the surface 1a. Since other configurations of the ultrasonic inspection apparatus 500 are the same as those of the ultrasonic inspection apparatus 100, description thereof is omitted. Also, in the following description, the case where the linear array probe 11 moves along all directions of the surface 1a will be described.

In the fifth embodiment, as shown in FIG. 14, it is assumed that the length of the linear array probe 11 is shorter than the uneven surface 2A of the pipe 1 in the extending direction. Then, the user moves the linear array probe 11 a plurality of times along the extending direction of the surface 1a so as to cover the range of the uneven surface 2A, as indicated by broken and solid arrows in FIG. The ultrasonic inspection apparatus 500 includes a device (not shown) that moves the linear array probe 11 along the extension direction, and the control unit 21 drives the device (not shown) according to user instructions to move the linear array probe 11.

The coordinates of the plurality of probes 110 accompanying the movement of the linear array probe 11 are calculated based on the amount of movement of the linear array probe 11 . The amount of movement of the linear array probe 11 may be measured by any means. For example, an encoder (not shown) may be used to measure the amount of movement from the initial position, or the amount of movement may be calculated using image processing while photographing the linear array probe 11 with an imaging device (camera). good. Alternatively, the plurality of probes 110 may be freely movable within the linear array probe 11, and only the plurality of probes 110 may be moved along the extending direction. In that case, the length of the linear array probe 11 itself needs to cover the range of the uneven surface 2A.

In the fifth embodiment, the calculation unit 20 executes the data collection step of step S1 and the data synthesis step of steps S2 to S5 shown in FIG. 3 each time the linear array probe 11 is moved a plurality of times. As a result, a calculation result of drawing the inside of the pipe 1 is obtained for each movement position of the linear array probe 11 . By synthesizing all the calculation results obtained for each movement position of the linear array probe 11, the calculation unit 20 can obtain the drawing result of the inside of the pipe 1 by synthesizing the calculation results of all the movement ranges of the linear array probe 11. can.

With this configuration, it is possible to inspect the pipe 1 by superimposing the calculation results of the data collection step and the data synthesis step that are performed a plurality of times while moving the entire plurality of probes 110 . That is, even if the length of the linear array probe 11 is shorter than the uneven surface 2A of the pipe 1 in the extending direction, the surface shape of the pipe 1 including the end of the uneven surface 2A is specified with higher accuracy, and the specified surface shape Based on, it is possible to obtain the drawing result of the inside of the pipe 1 with high accuracy.

As described above, in the fifth embodiment, the piping 1 is inspected by superimposing the calculation results of the data collection step and the data synthesis step executed a plurality of times while moving the entire plurality of probes 110. Indicated. However, by moving a single probe in multiple steps, the data collection step is executed for each multiple moves, and the calculation result obtained by superimposing the data collected in the data synthesizing step is obtained. good.

[Sixth embodiment]
Next, an ultrasonic inspection apparatus and an ultrasonic inspection method according to a sixth embodiment will be described. FIG. 15 is an explanatory diagram schematically showing a main part of an ultrasonic inspection apparatus according to the sixth embodiment. In the first to fifth embodiments, calculation processing using the linear array probe 11 (and the linear array probe 41) in which a plurality of probes 110 are arranged on a two-dimensional plane has been mainly described. An ultrasonic inspection apparatus 600 shown in FIG. 15 includes a matrix array probe 61 in which a plurality of probes 110 are arranged in a matrix array on a three-dimensional plane. The rest of the device configuration of the ultrasonic inspection device 600 is the same as that of the first embodiment, so the description is omitted.

The matrix array probe 61 has N probes 110 arranged in N columns. Therefore, when the data acquisition step of step S1 shown in FIG. 3 is executed using the matrix array probe 61, N×N matrix-type data are acquired for each column of the ultrasonic signal S. That is, N×N×N pieces of data are collected by all the probes 110, and the N×N×N pieces of data about this ultrasonic signal S are collected from the pipe 1 by the ultrasonic signal S. scanned data.

In the sixth embodiment, the calculation unit 20 uses the N×N×N pieces of data about the ultrasonic signal S described above to perform the data collection step of step S1 and the data synthesis of steps S2 to S5 shown in FIG. Execute the step. With this configuration, the data collection step of step S1 and the data synthesizing step of steps S2 to S5 are executed in a three-dimensional space, and drawing results of the inside of the pipe 1 can be obtained in a wider range and with high accuracy.

In addition, the configurations of the second embodiment to the sixth embodiment described above may all be implemented at the same time.

1 Piping 1a Surface 2 Welding Part 2A Concavo-convex Surface 2C Center Point 2E End Point 2S Start Point 3 Imaginary Inclined Surface 4 Orthogonal Surface 10 Flaw Detector 11, 41 Linear Array Probe 12 Pulser 13 Receiver 14 Data Storage Unit 15 Control Element Switching Unit 20 Calculation Unit 21 Control unit 22 Storage unit 23 First arithmetic processing unit 24 Second arithmetic processing unit 30 Operation/display unit 31 Calculation result display unit 32 Inspection condition setting unit 33 Calculation condition setting unit 61 Matrix array probe 100, 200, 500, 600 Ultrasound Inspection device 110 Probe 110A Transmission/reception surface A, B Medium M Image P, P _k pixel P1 to P7 row S Ultrasonic signal

Claims (13)

An ultrasonic inspection method for scanning and inspecting an inspection object with ultrasonic waves,
Using a plurality of probes that transmit ultrasonic signals to the test object and receive ultrasonic signals reflected from the test object through a medium that propagates the ultrasonic signal, the test object with an ultrasonic signal; and
a data synthesizing step of processing and synthesizing the ultrasonic signal data collected in the data collecting step;
The data synthesizing step includes:
a primary drawing step of drawing an image including the surface of the object to be inspected in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collecting step;
In the image drawn in the primary drawing step, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. , a shape identification step of identifying the positions of the extracted pixels as the surface shape of the inspection object ;
The data synthesizing step includes:
Of the surface shape identified in the shape identifying step, a position where the propagation time of the ultrasonic signal from the probe to the arbitrary pixel is the minimum is calculated, and a path passing through the calculated position of the surface shape is calculated. a path calculation step as a propagation path of the ultrasonic signal;
Amplitude value synthesis for synthesizing the amplitude values by matching the timing and pixels at which the amplitude values increase based on the propagation path calculated in the path calculation step for the data of the ultrasonic signal acquired in the data acquisition step. step and
An ultrasonic inspection method, further comprising : An ultrasonic inspection method for scanning and inspecting an inspection object with ultrasonic waves,
Using a plurality of probes that transmit ultrasonic signals to the test object and receive ultrasonic signals reflected from the test object through a medium that propagates the ultrasonic signal, the test object with an ultrasonic signal; and
a data synthesizing step of processing and synthesizing the ultrasonic signal data collected in the data collecting step;
The data synthesizing step includes:
a primary drawing step of drawing an image including the surface of the object to be inspected in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collecting step;
In the image drawn in the primary drawing step, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. , a shape identification step of identifying the positions of the extracted pixels as the surface shape of the inspection object ;
Along the surface shape specified in the shape specifying step, the ultrasonic signal transmission/reception surface formed along the arrangement direction of the plurality of probes is curved, and the data acquisition step, the primary drawing step and the An ultrasonic inspection method, characterized in that the shape identification step is performed again . An ultrasonic inspection method for scanning and inspecting an inspection object with ultrasonic waves,
Using a plurality of probes that transmit ultrasonic signals to the test object and receive ultrasonic signals reflected from the test object through a medium that propagates the ultrasonic signal, the test object with an ultrasonic signal; and
a data synthesizing step of processing and synthesizing the ultrasonic signal data collected in the data collecting step;
The data synthesizing step includes:
a primary drawing step of drawing an image including the surface of the object to be inspected in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collecting step;
In the image drawn in the primary drawing step, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. , a shape identification step of identifying the positions of the extracted pixels as the surface shape of the inspection object ;
The primary drawing step includes:
estimating the tilt angle of the surface of the inspection object based on the coordinates of the probe that transmitted and received the strongest ultrasonic signal and the transmission and reception time of the strongest ultrasonic signal for each pixel;
calculating, for each pixel, an angle of incidence and an angle of reflection of an ultrasonic signal with respect to the surface based on the estimated tilt angle;
An ultrasonic inspection method , wherein the image is drawn by applying an enhancement correction to data of ultrasonic signals whose incident angle and reflection angle are similar to each other. 4. The superimposed image according to any one of claims 1 to 3, wherein the primary drawing step draws the image in a predetermined range that includes a surface of the inspection object. SOUND INSPECTION METHOD. 5. The method according to any one of claims 1 to 4, wherein the shape identifying step extracts pixels having the pixel intensity equal to or greater than a predetermined threshold among the pixels having the maximum pixel intensity. Ultrasonography method as described. The shape identifying step sets the pixel intensity to a continuous value along a direction perpendicular to the extension direction, and extracts a pixel having the maximum pixel intensity based on a value obtained by applying a differential filter to the continuous value. ,
6. The differential filter according to any one of claims 1 to 5, wherein the differential filter has higher sensitivity at the end of the uneven surface formed by the surface than at the center. Ultrasound examination method. An ultrasonic inspection apparatus that scans and inspects an object to be inspected with ultrasonic waves,
a plurality of probes that transmit ultrasonic signals to the test object and receive ultrasonic signals reflected from the test object through a medium that propagates the ultrasonic signals;
Using the plurality of probes, data collection processing for collecting data obtained by scanning the inspection object with ultrasonic signals, and data synthesis for processing and synthesizing the data of the ultrasonic signals collected in the data collection processing and an arithmetic processing unit that executes processing,
The arithmetic processing unit is
a primary drawing process of drawing an image including the surface of the inspection object in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collection process;
In the image drawn by the primary drawing process, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. and a shape identification process for identifying the positions of the extracted pixels as the surface shape of the inspection object ,
The arithmetic processing unit is
Among the surface shape identified in the shape identification process, a position where the propagation time of the ultrasonic signal from the probe to the arbitrary pixel is the minimum is calculated, and a route passing through the calculated position of the surface shape is calculated. A path calculation process as a propagation path of the ultrasonic signal;
Amplitude value synthesis for synthesizing the amplitude values by matching the timing and pixels at which the amplitude values increase based on the propagation path calculated in the path calculation process for the ultrasonic signal data collected in the data collection process. processing and
An ultrasonic inspection apparatus , further comprising : An ultrasonic inspection apparatus that scans and inspects an object to be inspected with ultrasonic waves,
a plurality of probes that transmit ultrasonic signals to the test object and receive ultrasonic signals reflected from the test object through a medium that propagates the ultrasonic signals;
Using the plurality of probes, data collection processing for collecting data obtained by scanning the inspection object with ultrasonic signals, and data synthesis for processing and synthesizing the data of the ultrasonic signals collected in the data collection processing and an arithmetic processing unit that executes processing,
The arithmetic processing unit is
a primary drawing process of drawing an image including the surface of the inspection object in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collection process;
In the image drawn by the primary drawing process, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. and a shape identification process for identifying the positions of the extracted pixels as the surface shape of the inspection object ,
The arithmetic processing unit performs the data collection process, the primary drawing process, and the shape identification process in a state in which the transmitting/receiving surfaces of the plurality of probes are curved along the surface shape identified in the shape identification process. An ultrasonic inspection apparatus characterized by re-executing . An ultrasonic inspection apparatus that scans and inspects an object to be inspected with ultrasonic waves,
a plurality of probes that transmit ultrasonic signals to the test object and receive ultrasonic signals reflected from the test object through a medium that propagates the ultrasonic signals;
Using the plurality of probes, data collection processing for collecting data obtained by scanning the inspection object with ultrasonic signals, and data synthesis for processing and synthesizing the data of the ultrasonic signals collected in the data collection processing and an arithmetic processing unit that executes processing,
The arithmetic processing unit is
a primary drawing process of drawing an image including the surface of the inspection object in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collection process;
In the image drawn by the primary drawing process, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. and a shape identification process for identifying the positions of the extracted pixels as the surface shape of the inspection object ,
The primary rendering process includes:
estimating the tilt angle of the surface of the inspection object based on the coordinates of the probe that transmitted and received the strongest ultrasonic signal and the transmission and reception time of the strongest ultrasonic signal for each pixel;
calculating, for each pixel, an angle of incidence and an angle of reflection of an ultrasonic signal with respect to the surface based on the estimated tilt angle;
An ultrasonic inspection apparatus , wherein the image is drawn by applying enhancement correction to data of ultrasonic signals whose incident angle and reflection angle are similar to each other. The shape identification process sets the pixel intensity to a continuous value along a direction orthogonal to the extension direction, and extracts a pixel having the maximum pixel intensity based on a value obtained by applying a differentiation filter to the continuous value. ,
10. The differential filter according to any one of claims 7 to 9 , wherein the differential filter has higher sensitivity at the end of the uneven surface formed by the surface than at the center. ultrasound equipment. Using a plurality of probes that transmit ultrasonic signals to an object to be inspected and receive ultrasonic signals reflected from the object to be inspected through a medium that propagates the ultrasonic signals, the object to be inspected a data acquisition step of acquiring data scanned with ultrasound signals;
a data synthesizing step of processing and synthesizing the ultrasonic signal data collected in the data collecting step;
with
The data synthesizing step includes:
a primary drawing step of drawing an image including the surface of the object to be inspected in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collecting step;
In the image drawn in the primary drawing step, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. , a shape identification step of identifying the positions of the extracted pixels as the surface shape of the inspection object ;
The data synthesizing step includes:
Of the surface shape identified in the shape identifying step, a position where the propagation time of the ultrasonic signal from the probe to the arbitrary pixel is the minimum is calculated, and a path passing through the calculated position of the surface shape is calculated. a path calculation step as a propagation path of the ultrasonic signal;
Amplitude value synthesis for synthesizing the amplitude values by matching the timing and pixels at which the amplitude values increase based on the propagation path calculated in the path calculation step for the data of the ultrasonic signal acquired in the data acquisition step. step and
A program that causes a computer to execute each of the above steps , further comprising : Using a plurality of probes that transmit ultrasonic signals to an object to be inspected and receive ultrasonic signals reflected from the object to be inspected through a medium that propagates the ultrasonic signals, the object to be inspected a data acquisition step of acquiring data scanned with ultrasound signals;
a data synthesizing step of processing and synthesizing the ultrasonic signal data collected in the data collecting step;
with
The data synthesizing step includes:
a primary drawing step of drawing an image including the surface of the object to be inspected in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collecting step;
In the image drawn in the primary drawing step, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. , a shape identification step of identifying the positions of the extracted pixels as the surface shape of the inspection object;
Along the surface shape specified in the shape specifying step, the ultrasonic signal transmission/reception surface formed along the arrangement direction of the plurality of probes is curved, and the data acquisition step, the primary drawing step and the A program for causing a computer to execute each of the above steps, characterized in that the shape specifying step is executed again . Using a plurality of probes that transmit ultrasonic signals to an object to be inspected and receive ultrasonic signals reflected from the object to be inspected through a medium that propagates the ultrasonic signals, the object to be inspected a data acquisition step of acquiring data scanned with ultrasound signals;
a data synthesizing step of processing and synthesizing the ultrasonic signal data collected in the data collecting step;
with
The data synthesizing step includes:
a primary drawing step of drawing an image including the surface of the object to be inspected in an area including a plurality of pixels partitioned in a grid pattern based on the ultrasonic signal data collected in the data collecting step;
In the image drawn in the primary drawing step, a pixel having the maximum pixel intensity is extracted from among the plurality of pixels arranged along a direction orthogonal to the extending direction of the surface of the inspection object. , a shape identification step of identifying the positions of the extracted pixels as the surface shape of the inspection object;
The primary drawing step includes:
estimating the tilt angle of the surface of the inspection object based on the coordinates of the probe that transmitted and received the strongest ultrasonic signal and the transmission and reception time of the strongest ultrasonic signal for each pixel;
calculating, for each pixel, an angle of incidence and an angle of reflection of an ultrasonic signal with respect to the surface based on the estimated tilt angle;
A program for causing a computer to execute each of the above steps , wherein the data of the ultrasonic signal whose incident angle and the reflected angle are similar to each other are subjected to enhancement correction to draw the image.

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