Dynamic detection method using ultrasound imaging

Abstract

The invention relates to a dynamic method for representing data of a component (1) to be inspected, said method comprising: - a step of acquisition of data on the component (1) to be inspected by a multi-element sensor (2), said step comprising: - emission of an ultrasonic shot (E); and - reception of a return wave (R) returned by the component (1) as a result of the ultrasonic shot (E); said method also comprising a step of generation of data representative of the component (1) to be inspected; characterized in that said method also comprises a relative movement between the sensor (2) and the component (1) to be inspected during the data acquisition step, and in that said method also comprises a step of generation of corrected data representative of the component to be inspected by simulating the relative movement between the sensor (2) and the component (1) to be inspected up to a reference position.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing, such as nondestructive conformity testing of metal products. More specifically, this invention relates to ultrasonic testing for the presence of defects within tubular metal products. Background Technology

[0002] Metal pipes are widely used in various sectors of the energy industry, such as power generation, oil and gas, and mechanical engineering. Like most metallurgical products, pipes are susceptible to manufacturing defects, such as material inclusions in the steel, cracks on its inner or outer surfaces, or even porosity. Generally, any inhomogeneity within the steel matrix is ​​considered a defect that may adversely affect the mechanical strength of the pipe during use.

[0003] Therefore, after the pipes are manufactured, they are inspected not only to detect any defects, but also, where appropriate, to determine information that is helpful in assessing the danger of these defects, particularly their size, depth, location, nature, and even orientation, as well as whether these pipes conform to standards.

[0004] In particular, non-destructive testing techniques utilizing ultrasound are employed. Ultrasonic waves propagate through a pipe, and the search is conducted for waves in the reflected waves that cannot be attributed to the pipe's geometry. Defects, such as any inclusions or absences in the material, constitute variations within the wave propagation medium, and thus cause some of the ultrasound's energy to be reflected when they are struck by these ultrasonic waves.

[0005] One type of sensor used for ultrasonic detection is a multi-element, sequentially controlled sensor, often referred to as a "multi-element transducer" or "phased array transducer." This type of sensor comprises multiple electroacoustic elements, typically in the form of piezoelectric elements. These piezoelectric elements can be distributed on the active surface of the sensor surrounding the pipe being detected, or along the main alignment direction, to form an "array."

[0006] In an acquisition strategy known as FMC (Full Matrix Capture), for a multi-element sensor containing n elements, each of the n elements is excited once, and these n elements are excited consecutively to generate n consecutive ultrasonic bursts. The processing circuitry records the individual responses (hereinafter referred to as A-Scans) of the n elements of the sensor for each of the n bursts. For each element, this individual response represents the amplitude of the ultrasonic wave received by that element over a given listening duration. The n² recorded A-Scans can then be combined using the TFM (Total Focusing Method) algorithm to obtain an image representing a segment of the pipe.

[0007] To acquire a TFM image of the entire surface of the pipe, acquisition from multiple consecutive shots requires continuous relative movement of the sensor relative to the pipe. For a series of n shots, the sensor is held in a fixed position relative to the pipe to acquire a static TFM image of the pipe at that position, and then the sensor is moved relative to the pipe to perform the next series of n shots to acquire the next image of the pipe.

[0008] This method allows for obtaining accurate images of the pipe, but it requires a long acquisition time. Therefore, there is a need for a fast and reliable method to obtain accurate images of the component to be inspected. Summary of the Invention

[0009] The present invention is based on the idea of ​​rapidly and reliably acquiring data representing a component under inspection, such as a TFM image or A-Scan of a pipe. Specifically, the present invention is based on the idea of ​​acquiring data representing the component under inspection during relative movement between the sensor used to acquire said data and the component under inspection. More specifically, the present invention is based on the idea of ​​acquiring said data during continuous relative movement between the sensor and the component under inspection. The present invention takes into account the relative movement between the sensor and the component under inspection to generate reliable and accurate data representing the component under inspection.

[0010] According to one embodiment, the present invention provides a method for dynamically acquiring data representing a component to be detected, the method comprising:

[0011] - A step of acquiring data about a component under test, the data being obtained by a multi-element sensor including a transmitting element and a receiving element, the transmitting element being configured to emit a corresponding ultrasonic beam toward the component under test such that the ultrasonic beam propagates through the component under test, and the receiving element being configured to receive reflected waves caused by the ultrasonic beam and reflected by the component under test, i.e., reflected waves that are partially reflected and / or input into the component and then at least partially reflected or exit, the acquisition step including:

[0012] -Emitting ultrasonic waves from the transmitting element; and

[0013] - The receiving element receives ultrasonic waves during the listening duration, the received ultrasonic waves including reflected waves caused by the emitted ultrasonic waves being reflected by the component under test;

[0014] The method further includes the step of generating data representing the component to be detected based on the wave received by the receiving element;

[0015] The method is characterized by further comprising relative movement between the sensor and the component to be detected during the data acquisition step;

[0016] Furthermore, the method is characterized by further including a step of generating calibration data representing the component to be tested, the step of generating calibration data including:

[0017] - A corrected movement is calculated based on the relative movement between the sensor and the component under test, a reference position, and a duration relative to a reference time. The reference position corresponds to the relative position between the sensor and the component under test at a reference time, which occurs during the data acquisition step. The corrected movement corresponds to the relative movement between the sensor and the component under test from the relative position corresponding to the relative position between the sensor and the component under test at a time corresponding to the duration relative to the reference time, up to the reference position.

[0018] - The data representing the component under test is corrected according to the calculated correction movement in order to generate the correction data by simulating the relative movement between the sensor and the component under test from the relative position between the sensor and the component under test at the time of the specified duration all the way to the reference position.

[0019] The data representing the component under test is understood to be information related to the component's shape, thickness, and differences in the medium. For example, this data representing the component under test can be a cross-sectional image of the component, a matrix including multiple A-scans of the component, the form of the A-scans of the component, or any other form. Furthermore, the duration relative to a reference time corresponds to the time difference between the acquisition time of the data representing the component under test and the reference time; whether this duration is positive or negative depends on whether the acquisition time is before or after the reference time.

[0020] These features allow for the rapid and reliable acquisition of data representing the component under test. In fact, these features enable the rapid acquisition of this data due to the relative motion between the sensor and the component under test. Furthermore, thanks to corrections applied based on the relative movement between the sensor and the component under test, the reference position, and the duration relative to the reference time, data representing the component under test can still be acquired with high accuracy at the reference position despite the relative movement between the sensor and the component under test during data acquisition.

[0021] According to an embodiment, this dynamic acquisition method may include one or more of the following features.

[0022] In one embodiment, the relative movement between the sensor and the component to be detected is continuous. This continuous movement during data acquisition provides the method with good execution speed.

[0023] The component to be inspected can take many forms. In one embodiment, the component to be inspected is a pipe. This pipe can have many cross-sectional shapes, such as circular, square, or other shapes. Similarly, this pipe can have a constant or variable thickness.

[0024] According to one embodiment, correcting data representing a component to be inspected includes the step of performing a virtual movement (e.g., a virtual rotation about a rotation axis of the component to be inspected) on the data representing the component to be inspected in order to generate corrected data. Virtual movement is understood as a modification of data representing the contour of the component to be inspected in order to simulate a corrected movement of the component to be inspected without requiring the component to physically perform such a corrected movement.

[0025] According to one embodiment, calculating the correction movement includes calculating a corresponding correction movement for multiple or each data representing the component. According to one embodiment, the duration of the corresponding correction movement relative to a reference time corresponds to the duration of the time difference between the reference time and the time corresponding to the relative position between the sensor and the component to be detected, as represented by the data representing the component to be detected, and the reference time. Whether this duration is positive or negative depends on whether the time represented by the data representing the component to be detected is before or after the reference time. According to one embodiment, correction is performed for one, multiple, or each data representing the component to be detected based on the corresponding correction movement associated with the data representing the component to be detected.

[0026] According to one embodiment, the data acquisition steps include:

[0027] - Preferably, multiple ultrasonic beams are emitted continuously over time; and

[0028] - For each step of emitting the ultrasonic signal, the corresponding step in which the ultrasonic wave is received by the receiving element of the sensor during the corresponding listening duration, the received ultrasonic wave including at least one reflected wave caused by the corresponding emitted ultrasonic wave being reflected by the component to be detected.

[0029] Furthermore, the reference time is the emission time of one of the plurality of ultrasonic shots, and the duration is a multiple of the duration of two consecutive ultrasonic shots in the plurality of ultrasonic shots, so that a correction movement is calculated based on the relative movement between the sensor and the component under test between the emission of two different ultrasonic shots.

[0030] Two ultrasonic waves are emitted, and preferably all ultrasonic waves are excited sequentially, that is, at different emission times, in order to avoid interference between ultrasonic waves emitted from different emitting elements.

[0031] Corrected movement can be calculated for different portions of the relative movement between the sensor and the component under test. According to one embodiment, the corrected movement is calculated based on the relative movement between the sensor and the component under test between two different ultrasonic emissions, for example, two consecutive ultrasonic emissions. In other words, according to one embodiment, the reference position is the relative position between the sensor and the component under test at a reference moment corresponding to the emission of the ultrasonic emission.

[0032] By utilizing these features, particularly by emitting multiple beams from multiple emitting elements of the sensor, information about the component under test can be obtained at different orientations. Specifically, each ultrasonic beam allows for the acquisition of a set of data associated with the component under test along a path of identified ultrasonic waves, wherein the path begins at the location of the emitting element and generates a reflected wave, which is received at a corresponding location of the receiving element that receives the reflected wave.

[0033] According to one embodiment, the step of generating calibration data includes selecting a reference position. According to one embodiment, the reference position corresponds to the relative position between the component to be tested and the sensor during a selected ultrasonic firing. According to one embodiment, the reference position, and thus the corresponding reference time, is provided in advance, for example, by default selection, or by storage in the memory of the system implementing the method. According to one embodiment, the reference position is the relative position between the sensor and the component to be tested at the moment of the first firing. According to one embodiment, the reference position is the relative position between the sensor and the component to be tested at the moment of the last ultrasonic firing.

[0034] Therefore, a clear image of the part to be inspected can be obtained at a defined location (usually a reference location).

[0035] Data representing the component to be tested can be presented in various formats.

[0036] According to one embodiment, the data representing the component to be detected includes the intensity of ultrasonic waves reflected from the component to be detected and received by one or more or each receiving element of the sensor over time. This form of data representing the component to be detected is hereinafter referred to as A-Scan. According to one embodiment, the data representing the component to be detected includes an A-Scan generated from ultrasonic waves originating from the same ultrasonic wave signal emitted by the transmitting element of the sensor and received by one or more or each receiving element of the sensor.

[0037] According to one embodiment, the data representing the component to be detected includes an A-scan generated from multiple ultrasonic waves emitted successively by corresponding transmitting elements of the sensor, and preferably from multiple corresponding ultrasonic waves emitted successively by multiple different transmitting elements of the sensor, and received by one, multiple, or each receiving element of the sensor. According to one embodiment, the data representing the component to be detected includes a matrix comprising A-scans generated from multiple consecutive ultrasonic waves, and waves reflected by the component to be detected due to the ultrasonic waves and received by multiple receiving elements.

[0038] According to one embodiment, the data representing the component to be tested includes partial images of one, more, or each of a plurality of ultrasonic beams emitted during the acquisition step, wherein correcting the data representing the component to be tested includes modifying the partial images to simulate the movement of the component to be tested from the relative position between the transducer and the component to be tested shown in the partial images to a reference position to generate a corrected partial image.

[0039] According to one embodiment, a partial image is generated based on waves reflected by the component under test from the same ultrasonic wave. According to another embodiment, each point in the partial image is determined as a function of an A-scan, which is generated from waves reflected by the component under test and received by a receiving element after the transmission of the same ultrasonic signal.

[0040] According to one embodiment, the method includes generating an image representing a component to be detected based on calibration data. According to another embodiment, the method further includes the step of generating an image representing the component to be detected by overlaying multiple calibrated partial images.

[0041] Such partial and corrected partial images allow for the acquisition of images representing the part to be inspected, thus enabling the rapid and clear acquisition of information about the part to be inspected (e.g., the location, size, and other features of defects present in the part to be inspected).

[0042] According to one embodiment, the data representing the component to be detected includes a matrix, each row of which includes data representing the component to be detected generated after a corresponding ultrasonic firing, and each column of which includes data representing the component to be detected generated from a corresponding receiving element of the sensor. The calculation of the correction movement includes, for each ultrasonic firing, calculating a corresponding receiving offset represented by the number of receiving elements of the sensor. The correction includes, for one row, multiple rows, or each row of the matrix, applying an offset, represented by the number of columns, to the contents of the cells corresponding to the receiving offset of the row.

[0043] According to one embodiment, the listening duration has a start time equal to the emission time of the ultrasonic shot, wherein the listening duration is greater than or equal to the maximum time of flight between the emission of the ultrasonic shot and the reception of a wave reflected by a surface of the component under test opposite to the sensor by one of the receiving elements of the sensor, so as to calculate a correction movement based on the relative movement between the sensor and the component under test during the propagation time between the emission time of the ultrasonic shot and the reception time of the wave caused by the ultrasonic shot reflected by the component under test by one or more receiving elements. According to one embodiment, the final reception time corresponds to the listening duration, i.e., from that moment onwards, after the ultrasonic shot, one or more receiving elements are configured to no longer receive ultrasonic waves, particularly those caused by the ultrasonic shot. In other words, according to one embodiment, the correction movement is calculated based on the relative movement between the sensor and the component under test during the propagation time of the same ultrasonic shot from its emission to the reception of the wave caused by the ultrasonic shot and reflected by the component under test by one or more receiving elements.

[0044] According to one embodiment, the data representing the component to be detected includes, for each receiving element, a corresponding A-Scan that expresses the intensity of the wave received by the receiver as a function of the listening time of the receiving element.

[0045] According to one embodiment, calculating the correction movement includes dividing the corresponding A-Scan of the receiving element into multiple time blocks.

[0046] According to one embodiment, calculating the correction movement includes calculating the signal reception duration of one of the plurality of receiving elements based on the relative movement between the sensor and the component under test. According to one embodiment, each time block of one of the A-Scans has a duration equal to the reception duration of the receiving element relative to the relative movement of the sensor relative to the component under test.

[0047] According to one embodiment, the signal reception duration of one of the receiving elements corresponds to the duration during which the receiving element receives signals continuously emitted from the component under test during relative movement between the sensor and the component under test, wherein a duration longer than the reception duration causes the continuous signals to be received by an adjacent receiving element.

[0048] According to one embodiment, one, multiple, or each time block has a duration equal to the signal reception duration of a receiver that receives the wave reflected from the component under test, which allows the generation of the A-Scan.

[0049] According to one embodiment, calculating the correction movement includes calculating an offset, expressed in terms of the number of receiving elements, based on the relative positions of the receiving elements, the duration of signal reception by the receiving elements, and the time of transmission of the ultrasonic signal.

[0050] In one embodiment, the offset is an integer representing the number of A-scans by which the time block must be offset in the relative movement direction between the component to be detected and the sensor for a given time block of the original A-scan. In other words, the offset represents the number of A-scans between the original A-scan and the target A-scan to which the time block must be allocated for the same time range.

[0051] According to one embodiment, for a given time block of the original A-Scan, the offset is equal to the maximum number of consecutive receiving elements following the receiving element that receives the reflected wave of the original A-Scan in the relative movement direction between the sensor and the component to be detected, i.e., as a function of the reference position and the rotation direction of the component, wherein the cumulative sum of the signal reception durations is less than the time elapsed between the reference time and the start time of the time block.

[0052] According to one embodiment, the correction includes replacing a portion of a target A-Scan with at least one time block of the original A-Scan, wherein the target A-Scan corresponds to an A-Scan generated by the nth receiving element after the receiver that receives a portion of the energy of the reflected wave from the original A-Scan in the relative movement direction between the sensor and the component to be detected, where n is a calculated offset, and the portion of the target A-Scan has the same start and end times as the time block.

[0053] According to one embodiment, the relative movement between the sensor and the component to be detected is caused by the movement of the component to be detected and the sensor being held in a fixed position during the movement of the component to be detected. The movement of the component to be detected has an angular component about a rotation axis. The calculation of the corrected movement includes the step of calculating the angular movement of the component to be detected during the relative movement between the sensor and the component to be detected.

[0054] According to one embodiment, calculating the correction movement includes the step of calculating the angular movement of the component under test during the relative movement between the sensor and the component under test, and wherein the correction data representing the component under test includes simulating the rotation of the component under test about its rotation axis by an angle corresponding to the angular movement of the component under test in the acquisition step.

[0055] Therefore, by directly calibrating the A-Scan, and by taking into account the relative movement between the part under test and the sensor, including when the same ultrasonic beam propagates inside the part under test, a clear and accurate image of the part under test can be obtained.

[0056] According to one embodiment, the relative movement between the sensor and the component to be detected can have different characteristics.

[0057] In one embodiment, the relative movement between the sensor and the component to be detected is caused by the movement of the component to be detected and the sensor being held in a fixed position during the movement of the component to be detected. In one embodiment, the movement of the component to be detected has an angular component about a rotation axis (e.g., the longitudinal axis of the pipe in the context of a component to be detected in the form of a pipe). In one embodiment, the movement of the component to be detected has a longitudinal component along a longitudinal axis (e.g., the longitudinal axis of the pipe being measured). For example, the component to be detected is configured to move helically relative to the sensor. In one embodiment, the relative movement between the sensor and the component to be detected is caused by the movement of the sensor and the component to be detected being held in a fixed position.

[0058] According to one embodiment, calculating the correction movement includes the step of calculating the angular movement of the component to be detected. According to one embodiment, calculating the correction movement includes calculating the relative movement between the sensor and the component to be detected along the relative movement axis between the sensor and the component to be detected.

[0059] According to one embodiment, an image representing the component to be detected is generated based on the corrected A-Scan. Attached Figure Description

[0060] The invention will be better understood from the following description of several specific embodiments provided by way of non-limiting illustration with reference to the accompanying drawings, in which other objects, details, features, and advantages of the invention will become more apparent:

[0061] Figure 1 It is a cross-sectional view of a defective pipe and a multi-element sensor configured to generate data representing the pipe;

[0062] Figure 2 From Figure 1 The matrix generated by the sensors represents the data of the pipeline;

[0063] Figure 3 When the pipe is rotated by an angle α between two consecutive ultrasonic beams, Figure 1 A cross-sectional view of the pipe;

[0064] Figure 4 When the pipe moves at a rotational speed of 0.109 m / s, from Figure 2The image representing the pipeline is obtained from the matrix;

[0065] Figure 5 When the pipe moves at a rotational speed of 0.36 m / s, it is in relation to... Figure 4 Similar images;

[0066] Figure 6 When the pipe moves at a rotational speed of 0.8 m / s, it is in relation to... Figure 4 Similar images;

[0067] Figure 7 yes Figure 1 A cross-sectional view of the pipe, illustrating the different locations of pipe defects as the pipe rotates, against the backdrop of a circular multi-element sensor surrounding the pipe.

[0068] Figure 8 Is using Figure 7 The sensor obtained and Figure 2 A simplified representation of a matrix similar to the one shown, and a diagram illustrating the corrections made based on the rotation of the pipe;

[0069] Figure 9 yes Figure 1 A cross-sectional view of the pipe, illustrating the different locations of pipe defects as the pipe rotates during the same ultrasonic firing.

[0070] Figure 10 Through Figure 9 The sensor's representation of different A-scans obtained during ultrasonic firing;

[0071] Figure 11 From Figure 10 The diagram shows the representations of different corrected A-Scans obtained from the original A-Scan;

[0072] Figure 12 The amplitude of pixels in column 150 of the original image and the uncorrected original image are shown;

[0073] Figure 13 The diagram illustrates the modification used to generate... Figure 12 The original image data is used to obtain a corrected image that takes into account the relative movement between the pipe and the sensor, as well as the amplitude of the pixels in column 150 of the corrected image. Detailed Implementation

[0074] Oil, gas, or other extraction requires a large number of pipelines. Due to the many pressures these pipelines undergo during installation and extraction, they must meet standards to prevent any degradation and leakage into the environment.

[0075] Therefore, the tubular components manufactured for this type of mining must be inspected to ensure they are free of any defects that could compromise the mining process. To perform this inspection, sensors are used to generate data representing the pipe, which allows for the detection of the presence and characteristics of any defects within the pipe. Such defects could be surface cracks or even discontinuities in the material within the pipe wall.

[0076] Figure 1 The schematic diagram illustrates the cross-sectional views of pipe 1 and sensor 2.

[0077] Pipe 1 is cylindrical and has a longitudinal axis 3. Pipe 1 has a defect 4. Defect 4 is, for example, a crack in the wall of pipe 1, that is, the defect 4 is located between the outer surface 5 and the inner surface 6 of pipe 1.

[0078] To provide data representing pipe 1, sensor 2 includes multiple elements 7. Figure 1 In the embodiment illustrated in the diagram, sensor 2 includes a housing 8 that supports all elements 7. These elements 7 are aligned along the longitudinal axis 9 of sensor 2.

[0079] Each element 7 can emit ultrasonic waves E, also known as ultrasonic shooting E, and can also receive received waves R. As an example, element 7 can be a piezoelectric strip with a width of 1 mm and a length (also known as height) of 10 mm.

[0080] Sensor 2 is placed around the periphery of pipe 1, for example, above pipe 1, such that element 7 is oriented to emit ultrasonic waves E toward pipe 1. For example, sensor 2 is positioned such that its longitudinal axis 9 is perpendicular to the longitudinal axis 3 of pipe 1. A coupling agent separates pipe 1 from the surface of sensor 2 to allow the propagation of ultrasonic waves E, for example, a water column, gel, or any other medium that allows ultrasonic waves to propagate.

[0081] When an ultrasonic wave encounters a change in the medium during propagation, some of its energy is transmitted into the new medium, while some of its energy is reflected back at the interface between the two media. Therefore, for each change in the propagation medium encountered, some energy of the ultrasonic wave E emitted by element 7 of sensor 2 is returned, such that when the ultrasonic wave E reaches the outer surface 5 of pipe 1, the defect 4, or even the inner surface 6 of pipe 1, some of the energy of the ultrasonic wave E is reflected.

[0082] After each transmission of an ultrasonic wave E, a record is made of the ultrasonic wave received by each element 7 and / or the signal indicating the absence of ultrasonic waves. These records are made within a predetermined time period after the transmission of the ultrasonic wave E. During this time period, the ultrasonic waves received by element 7 include waves caused by reflections of ultrasonic waves on pipe 1.

[0083] Therefore, element 7 allows the generation of A-Scans representing pipe 1 from all received waves R, thus from the waves reflected after the ultrasonic wave E is emitted. Each A-Scan represents the amplitude of the received wave R received by element 7 over time, which is zero when element 7 is not receiving ultrasonic waves. Thus, these A-Scans make it possible to know the state of pipe 1 based on the position of the element emitting the ultrasonic wave E, the position of the element receiving the reflected wave, the time of flight of the ultrasonic wave, and the propagation medium.

[0084] When testing pipe 1, ultrasonic waves are continuously fired using the individual elements 7 of sensor 2. For each ultrasonic wave E, multiple A-Scan type data are thus obtained, including ultrasonic waves reflected from pipe 1 and received by the individual elements 7 of sensor 2.

[0085] For a sensor 2 comprising n elements 7, such as Figure 2 As shown in the diagram, the matrix records all A-scans generated based on the continuous ultrasonic wave emission E and the received ultrasonic waves R received by n elements 7, where the A-scans corresponding to the emission of element n and the reception of element m are recorded in cell E. n R m Such a matrix can be obtained in various ways, i.e., according to various strategies for acquiring A-scans. According to one embodiment, the matrix acquisition strategy is of the TFM (Total Focusing) type. According to one embodiment, the acquisition method is of the "sparse TFM" type (meaning that not all cells of the matrix contain A-scans (utilizing the transmission and / or reception of a subset of elements)), PWI (Plane Wave Imaging) (i.e., using multiple or all elements for transmission for each ultrasonic beam, utilizing different incident angles of delay to deflect the ultrasonic beam), sparse PWI, or any other acquisition method involving recording A-scans associated with numerous ultrasonic trajectories traveling between one or more transmitting elements and one or more receiving elements).

[0086] In such a matrix, each row of 10 represents the ultrasonic wave E emitted by the i-th element 7. i Following the emission, all A-Scans are generated from the n elements 7 of sensor 2. Thus, these A-Scans represent the ultrasonic waves emitted by E. i The received waves R1 to R2 are received by n elements 7 after the transmission. n .therefore, Figure 2 The first row 10 of the matrix shown in the diagram includes the received waves R1, R2, ..., R1 received by n elements 7 after the ultrasonic wave E1 is emitted from the first element 7. n-1 and R n The generated A-Scan corresponds to a set of data E1R1, E1R2, ..., E1R n-1E1R n Similarly, the last row 10 of the matrix includes ultrasonic waves emitted from the nth element 7. n Then, the received waves R1 to R2 are received by n elements. n The generated A-Scan corresponds to a set of data E n R1, E n R2、...、E n R n-1 and E n R n .

[0087] Furthermore, each column 11 of this matrix includes n consecutive ultrasonic shots E1 to E from n elements 7. n Subsequently, the received wave R received by the i-th element 7 i All A-Scans generated. Therefore, Figure 2 The first column 11 of the matrix shown in the diagram includes n ultrasonic waves E1 to E from n elements 7. n Subsequently, a set of data E1R1, E2R1, ..., E corresponding to the A-Scan generated by the received wave R1 of the first element 7 is generated. n R1.

[0088] then, Figure 2 The matrix shown (also known as the "FMC matrix") consists of n rows and n columns, with each row of 10 corresponding to the ultrasonic wave emitted by the i-th element 7 of sensor 2. i All subsequent A-Scans are generated, and each column 11 corresponds to the received wave R from the j-th element 7 of sensor 2. j The generated A-Scan.

[0089] pass Figure 2 The diagram illustrates a matrix comprising a set of data representing pipe 1, from which an image corresponding to a cross-sectional representation of pipe 1 can be reconstructed. In such an image, each pixel is associated with a value representing the propagation medium of pipe 1. For example, for each point in the image, such an image comprises the sum of the values ​​of each A-Scan of a matrix that is a function of the theoretical time of flight for that point. In other words, all A-Scans of the matrix are analyzed and compiled to define the acoustic characteristics of pipe 1 at that image point. For each A-Scan and each image point, the theoretical time of flight of the ultrasonic wave is associated, corresponding to the time required for the ultrasonic wave E leaving the transmitting element to reach the target image point, plus the time required for the wave reflected from the target image point to reach the receiving element corresponding to the A-Scan.

[0090] The amplitude of the A-Scan signal at such a defined theoretical time of flight represents the constituent material of pipe 1 at the target point. If pipe 1 does not exhibit defects or changes in the properties of the medium at the target image point, the emitted ultrasonic wave E is not reflected at that target point, resulting in no reflected wave, and the amplitude of the A-Scan signal from receiving element 7 is zero at the defined theoretical time of flight, or equivalent to background noise, such as background noise related to electronic systems or other interference. Conversely, if the target image point corresponds to a defect or change in the medium in pipe 1, the emitted ultrasonic wave E is reflected at that target image point, resulting in a non-zero amplitude of the A-Scan signal from receiving element 7 at the theoretical time of flight, which represents the wave reflected at the target image point. Thus, by summing the amplitudes of the individual A-Scan signals for each pixel, which vary with the corresponding theoretical time of flight, the properties of the medium in which the ultrasonic wave E propagates can be determined at each point in the image.

[0091] When continuous ultrasonic waves E are emitted without relative motion between sensor 2 and pipe 1, analyzing all A-scans of the matrix as a function of time of flight allows for obtaining clear and high-quality images of pipe 1. However, this relative immobility between sensor 2 and pipe 1 requires a significant amount of data acquisition time when acquiring data representing pipe 1. In fact, acquiring all A-scans of the matrix, i.e., from the first ultrasonic wave E1 to the last ultrasonic wave E1 received by receiver 7, requires considerable time. n The subsequent received wave R n To this end, it is necessary to maintain the relative positioning between sensor 2 and pipe 1. Therefore, this solution is difficult to be compatible with industrial processes that require the fastest possible analysis of long pipes 1.

[0092] To improve the speed of acquiring data representing pipe 1, pipe 1 and sensor 2 are set to move relative to each other during data acquisition. This relative movement between pipe 1 and sensor 2, and thus between pipe 1 and element 7, is preferably continuous.

[0093] In the context of the following description, data representing the pipe 1 is acquired by holding the sensor 2 in a fixed position, thereby holding the element 7 in a fixed position, and by moving the pipe 1 helically about its longitudinal axis 3. This relative movement between the pipe 1 and the element 7 is equivalent, on the one hand, to a translational movement of the element 7 along the longitudinal axis 3 of the pipe 1, and on the other hand, to a rotational movement about the longitudinal axis 3 of the pipe 1. This helical movement of the pipe 1 is, for example, carried out at a rotational speed about the longitudinal axis 3 of the pipe 1 at approximately 1 m / s. However, the relative movement between the pipe 1 and the sensor 2 can also be achieved by holding the pipe 1 in a fixed position and rotating the sensor 2 about the pipe 1, or by any other relative movement between the sensor 2 and the pipe 1.

[0094] The relative movement between pipe 1 and element 7 involves the relative movement of defect 4 relative to element 7. This relative movement results in an angular offset relative to the position of defect 4 with respect to the longitudinal axis 3 of element 7 around pipe 1. Thus, between two consecutive ultrasonic shots E, the data recorded by element 7 within the same matrix shows the angular offset corresponding to the relative movement between pipe 1 and element 7.

[0095] Figure 3 Diagram illustrating two consecutive ultrasonic shots E i and E i+1 The angle θ of the movement of defect 4. This movement of defect 4 is related to the rotation of pipe 1 in the rotation direction 24 about the longitudinal axis 3. For ease of reading and understanding, in Figure 3 The first position 12 and the second position 13 both show the same defect 4, thus illustrating the effect of two consecutive ultrasonic shots E i and E i+1 Between, the offset of angle θ in terms of the positioning of defect 4.

[0096] for Figure 3 Clearly, the above method cannot obtain a clear image of pipe 1. In fact, this is attributed to defect 4 in two consecutive ultrasonic shots E. i and E i+1 This movement between the two consecutive ultrasonic shots E i and E i+1 The generated A-Scan does not have the amplitude representing defect 4 at the same location in pipe 1. For the target point in the image of pipe 1, the amplitude is obtained by ultrasonic shooting E. i The resulting A-Scan has an amplitude corresponding to the presence of defect 4 at the first position 12, while the ultrasonic shooting E i+1The resulting A-scan has an amplitude corresponding to the presence of defect 4 at the second position 13, where the second position 13 is offset by an angle θ relative to the first position 12. Therefore, the sum of the amplitudes of different A-scans for a target point in the image no longer represents the structure of pipe 1, because for the same target point in the image, the amplitudes of the individual A-scans of the matrix do not correspond to the same position of defect 4. Consequently, the image obtained from the matrix is ​​blurry, and defect 4 is displayed inaccurately in the image, appearing as a circular arc trajectory instead of a clear spot.

[0097] The higher the rotational speed of pipe 1 around its longitudinal axis 3, the greater the blurring effect on the image. In fact, the faster pipe 1 rotates around its longitudinal axis 3, the greater the blurring effect of the two ultrasonic waves E. i and E i+1 The greater the angular offset θ between the defects 4, the more effective the two continuous ultrasonic shots E i and E i+1 The greater the angular offset of the positioning of defect 4, the greater the difference.

[0098] As an example Figures 4-6 The diagram is based on the reference above. Figures 1-3 Three images were generated against a background similar to pipe 1 and sensor 2, where pipe 1 is spiraling at different speeds. These precise images were generated using a 10MHz sensor 2, which comprises 64 elements 7 spaced 0.35mm from center to center.

[0099] Figure 4 The image shown is a precise image obtained by the ultrasonic shooting E through all elements 7 at a rotational speed of 0.109 m / s in pipe 1.

[0100] Figure 5 The image shown is a precise image obtained by the ultrasonic shooting E through all elements 7 at a rotational speed of 0.36 m / s in pipe 1.

[0101] Figure 6 The image shown is a precise image obtained by the ultrasonic shooting E through all elements 7 when the rotational speed of pipe 1 is 0.8 m / s.

[0102] When pipe 1 rotates at a decreasing speed of 0.109 m / s ( Figure 4 The rotation of pipe 2 had no significant effect on the obtained images, which showed that defect 4 was reliably located and measurable. However, the speed was too low and inconsistent with industrial rates.

[0103] With the pipe 1 rotating at a speed of 0.36 m / s, the obtained image allows for the detection of defect 4, but no further information about defect 4 is available. In fact, defect 4 is displayed in a blurred manner. Figure 5 The image is so small that only information about the existence of defect 4 can be obtained, but no further details about the characteristics of defect 4 can be obtained. When the rotational speed of pipe 1 is 0.8 m / s, as... Figure 6 As shown in the diagram, the obtained image is even more blurry, and the detection of defect 4 may also be problematic because it occupies a large surface area in the image, thus its amplitude is even smaller.

[0104] In order to obtain a clear image despite the relative motion between pipe 1 and sensor 2, the image reconstruction according to the invention advantageously takes into account the relative motion between pipe 1 and sensor 2 when acquiring data. For this purpose, the data representing pipe 1 acquired during the relative movement between pipe 1 and sensor 2 is corrected.

[0105] The correction is based on the idea of ​​acquiring data representing pipe 1 during the relative movement between pipe 1 and sensor 2, and then modifying that data by simulating the movement of pipe 1 around a reference position. This reference position is the relative position between sensor 2 and pipe 1 during the movement of pipe 1. This reference position can be predetermined or even arbitrarily chosen. The reference position can be any relative position between sensor 2 and pipe 1 during the movement of pipe 1, for example, during the first ultrasonic shot E1 or the last ultrasonic shot E2. n The reference time corresponding to the launch time, and the relative position between pipe 1 and sensor 2.

[0106] By modifying the data through simulating the relative movement between pipe 1 and sensor 2 up to a selected reference position, it is possible to generate corrected data that substantially corresponds to the data that would be obtained at the reference position without relative movement between pipe 1 and sensor 2. In other words, the idea is to generate data representing pipe 1 during relative movement between pipe 1 and sensor 2, and then modify that data to simulate the acquisition of said data in the context of a static relative position between pipe 1 and sensor 2.

[0107] Throughout the remainder of the description, this reference position and associated reference time correspond to the relative positions between pipe 1 and sensor 2 at the moment of emission of the first ultrasonic shot E1. Therefore, it is understood that movement of pipe 1 is equivalent to a reversal of the movement of pipe 1 for each shot simulation from the position corresponding to the data to be corrected to the position of the first ultrasonic shot E1.

[0108] To simulate the effect of two consecutive ultrasonic shots E iand E i+1 The relative movement between pipe 1 and sensor 2 is reversed, and each ultrasonic shot E is processed individually to generate a corresponding partial image. This partial image corresponds to a cross-sectional view of pipe 1 at its corresponding relative position to sensor 2, generated from data derived from a single ultrasonic shot E. Thus, multiple partial images are generated, each based on data obtained after a corresponding ultrasonic shot E. These partial images are generated in a manner similar to the method described above, but only considering the A-scan obtained for a given ultrasonic shot E (i.e., a single row of the FMC matrix), instead of an A-scan based on the entire matrix.

[0109] For each pixel of a partial image, such a partial image comprises the sum of the amplitudes of the A-scans generated from a single ultrasonic shot E. Thus, each pixel of the partial image is associated with the sum of the amplitudes of the A-scans originating from a single ultrasonic shot E.

[0110] However, due to the fact that each partial image is formed based on only a single ultrasonic shot E, each partial image represents the pipe 1 at a specific relative position relative to the sensor 2. In order to combine the various acquired partial images to obtain a clear and accurate image of the pipe 1, it is necessary to consider the angular offset between the individual successive ultrasonic shots E. To this end, the partial images generated from the A-Scan rows of the matrix are modified by simulating the reversal of the motion between the pipe 1 and the sensor 2 from the relative reference position to obtain a corrected partial image.

[0111] To simulate the reversal of the relative motion between pipe 1 and sensor 2, it is necessary to know the two consecutive ultrasonic shots E i and E i+1 The relative motion that is completed between pipe 1 and detector 2.

[0112] The spiral drive pipe 1 causes the pipe 1 to rotate around its longitudinal axis 3 at a V-shape. rot Against the backdrop of high-speed rotational movement, using sensor 2 with ultrasonic waves firing at PRF (pulse repetition frequency) times per second, according to the equation ΔL = V rot / PRF, the outer surface 5 of pipe 1 under two consecutive ultrasonic firing E i and E i+1 The distance ΔL that can be moved between them.

[0113] However, at time t, the transmitting element i i The first ultrasonic shot E i and the transmitting element i+1 at time t i+1 The second ultrasonic shot E i+1Between these two points, defect 4 was shifted by an angle Δθ. This angle Δθ corresponds to the distance between two consecutive ultrasonic shots E. i and E i+1 The time interval Δt = t i+1 -t i During this period, pipe 1 rotates around its longitudinal axis 3. Thus, in two consecutive ultrasonic beams E... i and E i+1 Between them, the distance ΔL covered by the outer surface 5 also conforms to the equation ΔL=R*Δθ, where R is the radius of pipe 1 at the outer surface 5, and Δθ is an angle expressed in radians, which corresponds to the distance between two consecutive ultrasonic waves E i With E i+1 The rotation of pipe 1 around its longitudinal axis 3.

[0114] From these two equations, we can derive Δθ = V rot / (R*PRF).

[0115] for Figure 2 The matrix shown in the diagram means that between the two rows 10 of the matrix, there are two consecutive ultrasonic shots E i and E i+1 Between them, according to the equation Δθ=V rot / (R*PRF), the recorded data offset angle Δθ. In other words, according to Figure 2 The partial image generated by the two consecutive rows 10 of the matrix shown in the diagram is geometrically offset by rotating by an angle Δθ around a point that serves as the rotation center of pipe 1 (theoretically its axis 3).

[0116] As described above, a portion of the image obtained from the first ultrasonic beam E1 is arbitrarily selected as a relative reference position. Then, for all other ultrasonic beams E1... i Calculate the angular position of pipe 1 relative to the reference angular position. In the example provided above, the second partial image obtained from ultrasonic shot E2 has an angular offset relative to the reference partial image, which is a rotation angle Δθ of pipe 1 about its rotation axis, and the i-th partial image obtained from the i-th ultrasonic shot has an angular offset relative to the reference partial image, which is a rotation angle (i-1)*Δθ about its rotation axis.

[0117] Then, the partial image is corrected by performing a rotation on the position of pipe 1 shown in the partial image that is opposite to the calculated angular offset. This correction is made when pipe 1 is subjected to two consecutive ultrasonic shots. i and E i+1 Given a rotation angle Δθ between them, this is equivalent to generating a partial image. Then, for each i-th partial image thus generated, the pipe 1 is simulated to rotate around its longitudinal axis 3 in a rotation direction opposite to the rotation direction of the pipe 1 by an angle α = (i-1)*Δθ.

[0118] for Figure 2 The matrix shown in the diagram uses the first portion of the image as a reference image. The corrected portion image generated from the first row 10 of the matrix is ​​the same as the portion image generated from the first row 10, because in this case, i = 1, and the correction to be performed relative to the reference portion image corresponds to a rotation angle α = (1-1)*Δθ = 0 about the vertical axis 3 of pipe 1. The corrected portion image generated from the second row 10 of the matrix corresponds to a rotation angle α = (2-1)*Δθ = Δθ about the vertical axis 3 of pipe 1, performed in a rotation direction opposite to the rotation direction of pipe 1 in the portion image generated from the second row 10 of the matrix. More generally, the corrected portion image generated from the nth row 10 of the matrix corresponds to a rotation angle α = (n-1)*Δθ about the vertical axis 3 of pipe 1, performed in a rotation direction opposite to the rotation direction of pipe 1 in the portion image generated from the nth row of the matrix.

[0119] Through this correction, the corrected partial image is equivalent to the image obtained from a single corresponding ultrasonic shot E by a sensor 2 fixed relative to pipe 1. Thus, even though the defect 4 moves during data acquisition, the corrected partial image obtained in this way also shows the same position of defect 4, which corresponds to the reference position. Then, by superimposing the corrected partial image obtained after rotation, that is, by adding the representative amplitude of pipe 1 to each pixel of the combined corrected partial image, a clear image of pipe 1 can be generated.

[0120] The image obtained by superimposing the rotated and corrected partial image does not produce a blurring effect and allows for a clear and accurate image of pipe 1, on which the shape and size of the detected defect 4 can be accurately characterized.

[0121] The above examples are as follows: Figure 3 Provided in the context of the pipe 1 shown, the pipe rotates relative to the element 7 aligned along the longitudinal axis 9 perpendicular to the longitudinal axis 3 of the pipe 1. However, this correction can be similarly applied to any other shape of the component to be detected, and any other type of relative movement. The idea is to generate data representing the component to be detected during the relative movement between the component and the sensor, and then modify that data by simulating the relative movement, such that the corrected data is equivalent to the data obtained without relative movement between the component to be detected and the sensor.

[0122] As an example, in the context of relative motion in the form of translation along the longitudinal axis 3 of pipe 1, i.e., without rotation of pipe 1, correction will lie in simulating the relative movement along the longitudinal axis 3 of pipe 1 all the way to the reference position, i.e., generating a partial image corrected by translational motion along axis 3 of pipe 1 in the direction of translational motion that will bring the partial image obtained from the matrix to the reference position.

[0123] Alternatively, the reversal of the motion of pipe 1 can be simulated without generating a partial image. In an alternative embodiment, correction is performed by directly offsetting the A-Scan in the matrix. This embodiment allows for obtaining a corrected matrix from which a clear image of the pipe cross-section can be directly obtained using the method described above for adding the amplitude of the A-Scan.

[0124] Figure 7 This illustrates the case where sensor 2 revolves around n elements. In this example, only pipe 1 rotates about its longitudinal axis 3. Specifically, this... Figure 7 The diagram illustrates the reception offset of the received wave R, expressed in terms of the number of receiving elements 7, caused by the rotation of pipe 1. Figure 7 In the process, an ultrasonic wave E is emitted at time t0, and this ultrasonic wave E is emitted at time t0. i Entering the pipe, the reflected wave R leaves pipe 1 at time ti+Δt and at time t f Received by receiving element 7.

[0125] When pipe 1 rotates by an angle Δθ during the time interval Δt, the rotation of pipe 1 causes a distance ΔL offset on the surface of sensor 2 between the emission and reception points of the ultrasonic beam E. To more easily understand this phenomenon, Figure 7 The example shown in the diagram illustrates the case where ΔL is equal to the spacing of sensor 2, that is, the distance between the centers of two adjacent elements 7, but the invention is equally applicable to any other value of ΔL.

[0126] exist Figure 7 As shown in the diagram, the following equation is obtained:

[0127] ΔL = Rs × Δθ (1)

[0128] Δθ = V θ × Δt (2)

[0129] V rot = V θ × Rt (3)

[0130] Where Rs is the inner radius of sensor 2, V θ V is the rotational angular velocity of pipe 1 (in rad / s). rotRt is the rotational speed of pipe 1 (in m / s), and Rt is the outer radius of pipe 1.

[0131] During the same ultrasonic wave E, the number D of elements between the emission point and the receiving point of the ultrasonic wave E on sensor 2. él The distance represented (expressed as the number of elements 7 of sensor 2) corresponds to the ratio between ΔL and the distance p between sensor 2, i.e., according to the following equation:

[0132] D él = ΔL / p (4).

[0133] From equations 1 to 3 above, we can conclude that:

[0134] D él = (Rs × V) rot × Δt) / (p × Rt) (5)

[0135] Therefore, by selecting the initial position of pipe 1 at the start of acquisition (typically, at the emission of the first ultrasonic shot E1) as the reference position, the movement of pipe 1 after listening to the received wave R after the first ultrasonic shot E1 is equal to, for example, in Figure 7 The diagram illustrates the rotation that occurs during the time interval Δt. Similarly, relative to this initial position of pipe 1, the movement of pipe 1 after receiving the received wave following the second ultrasonic shot E2 is equal to the rotation completed during the time interval Δt+1 / PRF. Generally, relative to this initial position of pipe 1 at the start of acquisition, the movement of pipe 1 upon receiving the received wave R caused by the k-th shot is equal to the rotation completed during the time interval Δt+(k-1) / PRF.

[0136] Therefore, for the k-th shot, the distance D between the firing point and the receiving point on sensor 2, expressed in terms of the number of elements on sensor 2, is... él (k) satisfies the following equation:

[0137] D él (k)= (ΔL+ ΔL2) / p (6),

[0138] in:

[0139] ΔL2=Rs×ΔθPRF (7), and

[0140] ΔθPRF = V θ / PRF (8)

[0141] Where ΔθPRF is the rotation angle of pipe 1 during the time interval 1 / PRF.

[0142] Therefore, we get:

[0143] D él (k)=[(Rs×V rot ) / (p×Rt)]×[Δt+ k-1) / PRF)] (9)

[0144] Once D is calculated for each of the acquired n ultrasonic shots E... él (k) allows for the following approximation:

[0145] If D él If (k) < 0.5, then the offset expressed in terms of the number of components is zero;

[0146] If 0.5 < D él If (k) < 1.5, then the offset expressed in terms of the number of elements is 1 element;

[0147] If x + 0.5 < D él If (k) < x + 1.5, then the offset expressed in terms of the number of elements is x + 1 elements.

[0148] D él The calculation allows for direct matrix correction via A-scans recorded in the direct offset matrix. Generally, as mentioned above... Figure 2 As mentioned above, when generating a matrix, the matrix's element E i R j The A-Scan includes the wave received after the ultrasonic wave is emitted by element i and its reflected wave is received by element j. However, due to the rotation of pipe 1 during data acquisition, in the absence of relative motion between pipe 1 and sensor 2, the wave that should be received by element j due to the ultrasonic wave E... i The reflected wave is formed by element j+D él (i) Reception. Therefore, A-ScanE is a function of the rotation direction of pipe 1 relative to the numbering direction of element 7 of sensor 2. i R j Actually located in the element E of the matrix i R (j±Dél(i)) Therefore, in order to obtain the correction matrix, the offset Dél needs to be considered. Then, by summing the amplitudes of the A-Scan of the obtained correction matrix, a complete and clear image can be obtained using the above method.

[0149] Figure 8 The diagram illustrates the initial position of the generated A-Scan in the matrix (denoted as E). i R j (s) and the corrected position of the A-Scan (representing E) i R jExample of a matrix (d). In this example, for each new ultrasonic shot E relative to the initial ultrasonic shot E1, the number of elements D is calculated. él The offset is increased by one element.

[0150] In Figure 8 In the first or initial ultrasonic shot E1, the A-Scan E in the first row 10 is not required. i R j The offset of (s). As a function of the rotation direction of pipe 1, the A-Scan E of the second row 10. i R j (s) Offset one column, in the example shown in the diagram, offset one column to the left. Similarly, A-Scan E in the third row, 10. i R j (s) towards Figure 8 Shift two columns to the left, and so on. This yields the correction matrix, where the A-Scan E associated with different elements... i R j (d) corresponds to the A-Scan generated under the condition of no relative motion between tube 1 and sensor 2. Then, the A-Scan E is generated at the appropriate flight time of the correction matrix as described above. i R j The amplitude of (d) is added together to generate a clear image.

[0151] When offset D él When this results in an offset of the content of cells outside the matrix, it is advantageous to increase the number of elements in the matrix accordingly, taking into account the virtual addition of elements 7 to sensor 2 when calculating the sharp image. These elements 7 are added sequentially with the elements 7 of sensor 2, i.e., with the same spacing. In an alternative embodiment, these A-Scan offsets outside the matrix can be ignored, and the sharp image can then be calculated starting from a reduced number of A-Scans.

[0152] To improve the clarity of the obtained image, the rotation of the pipe 1 about its longitudinal axis 3 as each ultrasonic shot E propagates in the pipe 1 can also be considered. In fact, if the rotational speed of the pipe 1 is particularly high, the defect 4 may shift significantly between the moment of emitting the ultrasonic shot E and the moment of receiving the reflected ultrasonic waves caused by that ultrasonic shot E.

[0153] The following explanation is provided in the context of the defect 4 moving due to high-speed rotation as the ultrasonic wave E propagates; however, this movement may also be related to factors other than rotational speed. Such factors could be, for example, the height of the water column and / or the thickness of the pipe 1, which also affect the time of flight of the ultrasonic wave, thus affecting the PRF (pulse repetition frequency).

[0154] From the perspective of a certain rotational speed of pipe 1, the rotation of pipe 1 during the propagation of the ultrasonic shot E causes the energy transmitted by the same ultrasonic shot to be received by element 7 with spatial receiving offset. Therefore, between the moment when element 7 of sensor 2 emits the ultrasonic shot E and the moment when the reflected wave R caused by the ultrasonic shot E is received, pipe 1 may have rotated, causing the reflected wave to be received by other elements 7 instead of element 7, which would have been the target receiving element 7 if pipe 1 had remained stationary.

[0155] Figure 9 The diagram illustrates this phenomenon of reception offset of the reflected wave during the propagation of the same ultrasonic beam E in pipe 1. Figure 9 In the middle, sensor 2 is circular, and element 7 is arranged in a circular manner around pipe 1.

[0156] In Figure 9 In the middle, component n emits ultrasonic waves to shoot E. n The ultrasonic shooting E n At time ti, the ultrasonic beam E impacts the outer surface 5 of pipe 1, at which point defect 4 is in the first position 14 relative to sensor 2. Then, the ultrasonic beam E... n It propagates in pipe 1.

[0157] At time ti+dt, where dt represents the rotation time of pipe 1, and pipe 1 rotates by an angle dξ. At time ti+dt, the ultrasonic wave E n Defect 4 has been reached, at which point defect 4 has a second position 15, and is caused by ultrasonic shooting E. n The reflected wave 16 from the defect 4 propagates toward the outer surface 5 of the pipe 1.

[0158] At time ti+k*dt, by the shot E n The reflected wave 16 generated by the reflection at defect 4 returns to the outer surface 5 of pipe 1 and leaves pipe 1. During the time ti+k*dt, pipe 1 has rotated by an angle k*dξ about its longitudinal axis 3. During the time k*dt, the outer surface 5 of pipe 1 has rotated according to the equation DL=V rot *k*dt rotates by distance DL.

[0159] If ultrasonic shooting E n The propagation time k*dt in pipe 1 and / or the rotational speed V of pipe 1 rotIf the angular distance of DL relative to the center separating the two adjacent elements 7 is negligible, and preferably negligible relative to the distance between the centers of the two adjacent elements 7 divided by 2, then the movement of pipe 1 relative to sensor 2 during the same ultrasonic firing E can be considered negligible. Therefore, the rotation of pipe 1 is considered insufficient to produce a receiving offset during the same ultrasonic firing E.

[0160] If ultrasonic shooting E n The propagation time k*dt in pipe 1 and / or the rotational speed V of pipe 1 rot If DL is greater than the distance between the centers of two adjacent elements 7, then some reflected waves received by receiving element 7 will typically be received by other elements. Therefore, the reflected wave R received by receiving element 25 after the ultrasonic wave E emitted by transmitting element 26 does not represent the propagation path identified for the association between receiving element 25 and transmitting element 26. Consequently, the A-Scan generated after receiving the wave reflected by receiving element 25 is incorrect.

[0161] Data E recorded in the matrix i R i That is, the received wave R received by each element 7 after each ultrasonic shot E. i The corresponding A-Scan itself is incorrect. Therefore, to obtain a clear image of pipe 1, the A-Scan E must be corrected in the matrix. i R i itself.

[0162] Similar to the correction of the aforementioned partial images or matrices, the correction of the A-Scan involves simulating the relative movement between pipe 1 and sensor 2 up to the reference position, so as to generate a corrected A-Scan that corresponds to the A-Scan obtained when there is no relative movement between pipe 1 and sensor 2.

[0163] To explain this offset phenomenon in A-Scan, an ultrasonic wave E emitted by the i-th element 7 was used. i and received by the same i-th unit 7 in the ultrasonic shooting E i The subsequent received wave R i The situation.

[0164] Assume the ultrasonic wave E between sensor 2 and pipe 1 i If the propagation medium does not move relative to sensor 2, then the shot E i The reflected wave (also known as the interface echo) generated by the impact on the outer surface 5 of the pipe 1 is not affected by the rotation of the pipe 1. Therefore, this interface echo is usually received by the i-th transducer 7.

[0165] As described above, in shooting E i Between the moment ti, when the impact wave 16 hits the outer surface 5 of the pipe 1, and the moment ti+k*dt, when the reflected wave 16 returns to the outer surface 5 of the pipe 1, the pipe 1 rotates by an angle k*dξ.

[0166] If k*dξ is greater than the angle ω formed by the center of pipe 1 and the centers of two adjacent elements 7, then the cause is the shooting E i The impact on defect 4 is directed towards the outer surface 5 of pipe 1. Therefore, the reflected wave, which would be received by the i-th element 7 if pipe 1 is not rotating, will not be emitted relative to the i-th element 7. Consequently, the reflected wave is received by the j-th element, which is different from the i-th element 7.

[0167] Therefore, if k*dξ is greater than the angle ω, then A-Scans distortion occurs, which needs to be considered by taking into account the ultrasonic shooting E. i They are corrected by the rotation k*dξ of pipe 1 during propagation in pipe 1. As described above, and similarly considering pipe 1 in two consecutive ultrasonic shots E i and E i+1 The rotation between them is based on the idea of ​​simulating the movement of pipe 1 up to a reference position, typically the reversal of the movement of pipe 1 at the moment the reference position is reached, in order to obtain a corrected A-scan that is substantially equivalent to the A-scan obtained when pipe 1 is not moving. For this purpose, for each ultrasonic shot E, the A-scan arising from the wave R received by the respective element 7 is generated at the first moment and then corrected at the second moment.

[0168] The first step in correcting an A-Scan is to calculate the time increment dtp that results in a rotation dlp equidistant from the centers of the two adjacent elements 7. Figure 9 In the example shown, this is equivalent to determining the angle ω that separates the centers of the two adjacent elements 7, and calculating the time dtp required for the pipe 1 to complete a rotation equivalent to that angle ω.

[0169] In the second time step, A-Scan is divided into blocks 17 of duration dtp. Figure 10 and Figure 11 In the middle, each block 17 is related to reference E. i R j (t x -t y The association means that it involves the j-th element after the i-th ultrasonic shot during the duration t. x -t y The received wave R.

[0170] Figure 10The diagram illustrates that, following the same ultrasonic wave E, multiple elements 7 receive the A-Scan 18 of the received wave R. Figure 10 In the diagram, each A-Scan 18 is generated from the received wave R received by element 7 during a series of time intervals dtp. Figure 10 In this process, each A-Scan 18 is then divided into multiple time blocks 17, each time block 17 having a duration dtp corresponding to the rotation duration of the pipe 1 required to cover the angle ω separating the centers of two adjacent elements 7.

[0171] As mentioned above, in Figure 10 In the A-Scan 18 shown in the diagram, each time block 17 does not necessarily represent an identification path between the transmitting element 26 and the receiving element 25, which allows the A-Scan to be generated at the corresponding time of flight. In fact, due to the rotation of the pipe 1, these blocks 17 are generated by reflected waves received by the receiving element 25, but due to the rotation of the pipe 1, these reflected waves should be received by other elements 7.

[0172] Therefore, for each A-Scan generated from the received wave R received from element 7, the correction of the A-Scan involves selecting a block 17 that should be received by other elements 7 and associating said block 17 with the element 7 that should normally receive said block 17. In the context of pipe 1 rotation, this is equivalent to shifting block 17 from the original A-Scan generated from the received wave R received by element 7 to the corresponding target A-Scan that should normally be received corresponding to the reflected wave of said block 17 if pipe 1 is not rotating.

[0173] Figure 11 The diagram illustrates from Figure 10 The diagram shows the original A-Scan and the individual A-Scans calibrated for each element 7.

[0174] exist Figure 10 In the time period d ti ~d ti+1 The received wave R during this period generates the i-th block 17. However, at time d... ti Pipe 1 has been rotated by an angle i*ω about its longitudinal axis 3. Therefore, the reflected wave represented in these i-th blocks 17 is received by element 7, which is offset by i blocks 17. In other words, in time period d ti ~d ti+1 During this period, the reflected wave received by the kth element 7 will be received by the kith unit 7 if there is no relative movement between the sensor 2 and the pipe 1.

[0175] Therefore, with the reference position corresponding to the emission time of the ultrasonic shot, the A-Scan correction performed by simulating the reverse motion of pipe 1 can be achieved by adjusting the time period d. ti ~d ti+1 The i-th block 17 is offset by i A-Scan 18s in the opposite rotation direction of pipe 1 to perform the operation. In other words, to correct the A-Scan 18, the block 17d of the A-Scan 18 generated by the n-th element 7... tpi -d tpi+1 The corresponding block 17, which is offset to element i+n, i.e., time period d tpi -d tpi+1 Block 17.

[0176] Therefore, in Figure 11 middle, Figure 10 Block 17 of A-Scan 18, as shown in the diagram, is offset to simulate the reversal of the movement of pipe 1. Thus, Figure 10 The i-th block of each line, 17 Figure 11 The middle is offset by i rows for correction. Figure 10 A-Scan18. In Figure 11 In this case, as obtained by the correction, each row then has a corrected A-Scan 18 corresponding to the A-Scan 18 that the element 7 associated with the row would obtain in the absence of relative movement between the pipe 1 and the sensor 2.

[0177] Therefore, through comparison Figure 10 and Figure 11 It can be seen Figure 10 The second block 17 of each line L (corresponding to time interval d) tp1 -d tp2 )exist Figure 11 The middle block is offset by one line to replace the second block 17 in the next line (i.e., line L+1). Similarly, Figure 10 The third block 17 of each line L (corresponding to time interval d) tp2 -d tp3 )exist Figure 11 The middle element is offset two lines to replace the third block in line L+2. For example, this corresponds to element 7 of the fifth element. Figure 11 The correction of A-Scan 19 (usually) Figure 11 (Fifth line) From time t0 to time d tp4 In order to include Figure 10 The first block of the fifth line, 20. Figure 10 The second block of the fourth line, 21. Figure 10 The third block of the third line, 22 and Figure 10The fourth block 23 in the second row. Thus, the corrected A-Scan 19 includes blocks 20-23 corresponding to the received wave R, which is received by each element 7 in the context of the pipe 1 rotating relative to the sensor 2, and which is only received by the fifth element 7 if there is no relative motion between the pipe 1 and the sensor 2.

[0178] exist Figure 11 In this context, the empty frames correspond to blocks 17 of the A-Scan with zero amplitude signals. These blocks 17 are not very destructive because they represent empty amplitude signals that do not change the acquired image. In any case, when the offset causes blocks 17 of the original A-Scan to be shifted outside the target A-Scan, it is advantageous to increase the duration of the target A-Scan by multiple blocks 17, similarly corresponding to a virtual increase in the matrix size described above.

[0179] In addition, to make the corrections made to A-Scan 18 easier to understand, Figures 9-11 The diagram illustrates the case of the circular sensor 2, where each element 7 covers a circular segment with the same angle ω around the pipe 1. Therefore, the rotation of the pipe 1 causes a receiving offset of the same reflected wave R for all elements 7, resulting in a change in the duration d used to divide the block 17. tp This is the same for all A-Scan18s. However, element 7 can be arranged in several ways. For example, element 7 can be aligned along the vertical axis, such as... Figure 1 and Figure 3 The situation is the same in the embodiment shown in the diagram. In this case, the curvature of the pipe 1 relative to the position of each element 7 needs to be considered. For this purpose, one or more d values ​​can be calculated by considering other parameters, such as the exit angle of the reflected wave or even the DL projected onto the alignment axis 9 of element 7. tp For each element 7, such calculations result in blocks 17 with different durations depending on the relative position of element 7 with respect to pipe 1. Similarly, in order to determine the offset of blocks 17 between different elements 7, the differences in the duration of blocks 17 between different elements 7 need to be taken into account.

[0180] Furthermore, in the example provided above for illustrative purposes, the relative motion between the calibrated pipe 1 and sensor 2 is an angular movement relative to the longitudinal axis 3 of pipe 1. However, this movement can be other types of movement, such as translational movement along the longitudinal axis 3 or other movements.

[0181] Figure 12 The diagram illustrates the original image ( Figure 12 The left part) and the amplitude of the pixels in column 150 of the original image ( Figure 12(The right side of the image). This original image was generated from the raw data, i.e., the raw data acquired during the relative motion between pipe 1 and sensor 2 before correction according to the invention. The original image shows defect 4 in pipe 1, but it is quite blurry and cannot accurately characterize defect 4.

[0182] Figure 13 The diagram illustrates an image corrected using the method described above, which utilizes the amplitude of pixels in column 150 of the partial image and the corrected image. This corrected image is clear and readily allows for accurate and reliable characterization of defect 4, even though the data used to generate the corrected image was obtained during relative motion between pipe 1 and sensor 2. The amplitude gain of the defect provided by the correction is 5.7 dB. Therefore, by means of this invention, a clear and accurate image of the component to be inspected can be obtained quickly and reliably, wherein the data enabling the acquisition of the corrected image is obtained during relative motion between pipe 1 and sensor 2.

[0183] The above description is provided in the context of, for example, a metal pipe 1, but the element to be tested may exhibit any other properties in terms of shape and / or material.

[0184] The above description is provided in the context of a sensor that includes element 7, which is capable of simultaneously emitting and receiving ultrasonic waves. However, such a sensor may include separate ultrasonic emitting and receiving elements.

[0185] Although the invention has been described with respect to several specific embodiments, it is obvious that the invention is by no means limited thereto, and the invention includes all technical equivalents of the described means, as well as combinations thereof, as long as they are within the scope of the invention.

[0186] Therefore, the example described above is performed in the context of a linear sensor 2; however, the method can be applied in the context of a sensor including two-dimensionally arranged elements 7, allowing the volume to be reconstructed in three dimensions in a manner equivalent to the reconstruction described above with respect to two-dimensional reconstruction of an image.

[0187] The use of the verbs “comprising” or “including” and their variant forms does not exclude the presence of other elements or steps besides those described in the claims.

[0188] In the claims, any reference numerals between parentheses shall not be construed as limiting the claims.

Claims

1. A dynamic acquisition method for dynamically acquiring data representative of a metal part (1) to be inspected, said method comprising: - a step of acquiring data about the metal part (1) to be inspected, said data being obtained by a multi-element sensor (2), said sensor (2) comprising a transmitting element and a receiving element, said transmitting element being configured to emit a respective ultrasonic shot (E) towards the metal part (1) to be inspected, so that said ultrasonic shot (E) propagates through the metal part (1) to be inspected, said receiving element being configured to receive reflected waves (R) reflected by the metal part (1) to be inspected resulting from said ultrasonic shot (E), said acquiring step comprising: - emitting an ultrasonic shot (E) from said transmitting element; and - said receiving element receiving ultrasonic waves during a listening duration, said received ultrasonic waves comprising reflected waves reflected by the metal part (1) to be inspected resulting from the emitted ultrasonic shot (E); said method further comprising a step of generating data representative of the metal part (1) to be inspected from the waves received by said receiving element; characterized in that, during said step of acquiring data, said method further comprises a step of moving one between said metal part (1) to be inspected and said sensor (2), so as to produce a relative movement between said sensor (2) and said metal part (1) to be inspected; and in that said method further comprises a step of generating corrected data representative of the metal part (1) to be inspected, said step of generating corrected data comprising: - calculating a correction movement from the relative movement between said sensor (2) and said metal part (1) to be inspected, a reference position and a duration with respect to a reference instant, wherein the reference position corresponds to a relative position between said sensor (2) and said metal part (1) to be inspected at a reference instant, wherein said reference instant occurs during said step of acquiring data, wherein said correction movement corresponds to a relative movement between said sensor (2) and said metal part (1) to be inspected from a relative position corresponding to the relative position between said sensor (2) and said metal part (1) to be inspected at an instant of said duration with respect to said reference instant, up to said reference position; and - applying a correction to the data representative of said metal part (1) to be inspected from the calculated correction movement, so as to generate said corrected data by simulating a relative movement between said sensor (2) and said metal part (1) to be inspected from the relative position between said sensor (2) and said metal part (1) to be inspected at said instant of said duration, up to said reference position. wherein said listening duration has a start instant equal to the instant of emission of the ultrasonic shot, said listening duration being greater than or equal to the maximum time of flight between the emission of an ultrasonic shot and the reception by one of the reception elements of the sensor of a wave reflected by the surface of the metal part (1) to be detected opposite said sensor, so that the correction movement is calculated as a function of the relative movement between the sensor (2) and the metal part (1) to be detected during the time of propagation between the instant of emission of an ultrasonic shot (E) and the instant of reception by the reception elements of a reflected wave caused by said ultrasonic shot (E) reflected by the metal part (1) to be detected.

2. Dynamic acquisition method according to claim 1, wherein the step of generating correction data comprises selecting said reference position.

3. Dynamic acquisition method according to claim 1 or 2, wherein the step of acquiring data comprises: - emitting a plurality of ultrasonic shots (E); and - for each step of emission of an ultrasonic shot (E), a corresponding step of reception of ultrasonic waves by said reception elements of the sensor (2) during a corresponding listening duration, said received ultrasonic waves comprising at least one reflected wave caused by the corresponding emitted ultrasonic shot reflected by the metal part (1) to be detected; and wherein said reference instant is the instant of emission of one of the plurality of ultrasonic shots and said duration is a multiple of the duration separating two consecutive ultrasonic shots of said plurality of ultrasonic shots, so that the correction movement is calculated as a function of the relative movement between the sensor (2) and the metal part (1) to be detected between the emission of two different ultrasonic shots.

4. Dynamic acquisition method according to claim 3, representing data of the metal part (1) to be detected comprising partial images for a plurality of ultrasonic shots (E) emitted during the acquisition step, the correction of the data representing the metal part (1) to be detected comprising a step of modifying said partial images so as to simulate the movement of the metal part (1) to be detected from the relative position between the sensor (2) and the metal part (1) to be detected shown in said partial images up to said reference position, so as to generate corrected partial images.

5. Dynamic acquisition method according to claim 4, further comprising a step of generating an image representing the metal part (1) to be detected by superimposing a plurality of corrected partial images. ​ 6. The dynamic acquisition method according to claim 3, wherein the data representative of the metal part under examination (1) comprise a matrix, each row of said matrix comprising data representative of the metal part under examination (1) generated after a corresponding ultrasonic shot (E), each column of said matrix comprising data representative of the metal part under examination (1) generated from a corresponding receiving element of said sensor (2), the calculation of the correction movement comprising, for each ultrasonic shot (E), the calculation of a corresponding receiving offset representative of the number of receiving elements of said sensor (2), the implementation of the correction comprising, for each row of said matrix, the implementation of an offset of the content of a cell of said row with the number of columns representative of the corresponding receiving offset of said cell.

7. The dynamic acquisition method according to claim 1, wherein the data representative of the metal part under examination (1) comprise, for each receiving element, a corresponding A-Scan (18) representative of the intensity of the waves received by the receiver, said corresponding A-Scan (18) being dependent on the listening time of said receiving element.

8. The dynamic acquisition method according to claim 7, wherein the calculation of the correction movement comprises the division of the corresponding A-Scan (18) of a receiving element into a plurality of time blocks (17).

9. The dynamic acquisition method according to claim 8, wherein calculating the correction movement comprises calculating a signal reception duration (d tp ) of a receiving element of the plurality of receiving elements as a function of the relative movement between the sensor (2) and the metal part (1) to be detected, and wherein, Each time block (17) of the A-Scan (18) has a duration equal to the reception duration (d tp ) of the receiving element for the relative movement of the sensor with respect to the metal part (1) to be detected.

10. The dynamic acquisition method according to claim 9, wherein calculating the correction movement comprises calculating a shift expressed in number of receiving elements as a function of the relative position of the receiving elements, the signal reception duration (d tp ) of the receiving elements and the emission instant of the ultrasonic shot (E).

11. The dynamic acquisition method of claim 10, wherein, For a given time block (17) of the original A-Scan, said offset is equal to the maximum number of consecutive receiving elements, in the direction of the relative movement between the sensor (2) and the metal part (1) to be detected and starting from the receiving element that received the reflected wave of the original A-Scan, whose signal reception duration (d tp ) is less than the duration elapsed between the reference instant and the instant of start of said time block (17).

12. The dynamic acquisition method according to claim 11, wherein the implementation of the correction comprises, for at least one time block (17) of the original A-Scan, the replacement of a portion of the target A-Scan with said time block (17), said target A-Scan corresponding to the A-Scan generated from the nth receiving element following the receiver that received the reflected waves of the original A-Scan in the direction of the relative movement between said sensor (2) and said metal part under examination (1), n being the calculated offset, the portion of the target A-Scan having the same start and end instants as said time block.

13. The dynamic acquisition method according to claim 1 or 2, wherein the relative movement between said sensor (2) and said metal part under examination (1) is caused by the movement of the metal part under examination (1) and by the fact that said sensor (2) is held in a fixed position during the movement of the metal part under examination (1), the movement of the metal part under examination (1) having an angular component about the rotation axis (3), the calculation of the correction movement comprising the step of calculating the angular movement (dθ) of the metal part under examination (1) during said relative movement between said sensor (2) and said metal part under examination (1).

14. The dynamic acquisition method according to claim 13, wherein the calculation of the correction movement comprises the step of calculating the angular movement of the metal part under examination (1) during said relative movement between said sensor (2) and said metal part under examination (1), and wherein the correction of the data representative of the metal part under examination (1) comprises the simulation of the rotation of the metal part under examination (1) about its rotation axis (3) by an angle equal to the angular movement of the metal part under examination (1) during the acquisition step up to said reference position.

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