A radiographic detection record coding traceability system and method

Abstract

The present application relates to the technical field of material detection, and specifically discloses a kind of ray detection record coding traceability system and method, according to the three-dimensional geometric data of the material to be detected, the geometric relationship of radiation source, detector and the attenuation array of rotating disc in each acquisition position is determined, traceability information is converted into the coding pattern sequence distributed in multiple acquisition positions, and the complementary attenuation state of attenuation unit is used to carry out ray acquisition.According to the air field radiation intensity and the exit intensity, the incident intensity is corrected, the coding pattern attenuation line integral value and the attenuation line integral value of the material to be detected are separated from the acquisition data, and the state deviation is used to participate in voxel attenuation coefficient updating.According to the actual attenuation state, the traceability information is restored, and the traceability information is saved corresponding to the three-dimensional image.The present application can reduce the interference of coding process on material image reconstruction result, and form the detection traceability record corresponding to the three-dimensional image.

Description

Technical Field

[0001] This invention relates to the field of materials testing technology, specifically to a radiographic testing record coding and traceability system and method. Background Technology

[0002] Radiographic testing obtains information about the internal structure of a material by recording the intensity changes of radiation as it passes through it. Two-dimensional or three-dimensional images are then reconstructed based on projection data from different acquisition locations. To record the object being tested, the batch being tested, and the testing time, a radiographically identifiable mark is typically attached to the surface of the material, or a coded plate with a fixed pattern is placed between the radiation source and the material, allowing the marking information to be recorded along with the material's projection data.

[0003] Markers attached to the surface of the material being tested increase the attenuation of local ray paths. When the marker projection overlaps with the material structure projection, grayscale variations unrelated to the internal structure of the material are easily generated in the reconstruction results. When a fixed encoding plate maintains the same pattern at multiple acquisition locations, the encoding plate projection is continuously superimposed on the material projection. Deviations in the encoding plate position, changes in the incident ray direction, and fluctuations in the emission intensity of the radiation source can all create residual attenuation components. Furthermore, the amount of information that a fixed pattern can carry is limited by the area of ​​the encoding plate and the number of pattern units. Summary of the Invention

[0004] The purpose of this invention is to provide a system and method for ray detection, recording, coding, and traceability, thereby solving the aforementioned technical problems.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for tracing and coding X-ray inspection records includes the following steps: S1: Acquire the three-dimensional geometric data of the material being tested to determine the trajectory of the radiation source, the detector acquisition position, and the spatial pose of the rotating attenuation array; S2: Generate a sequence of coded patterns based on the traceability information, and set the attenuation state of multiple attenuation units in the attenuation array according to each coded pattern; S3: Control the radiation source to move along the radiation source trajectory and record the actual attenuation state and radiation intensity data after passing through the material being tested at each acquisition location; S4: Obtain the integral value of the total attenuation line of each ray path based on the incident intensity and radiation intensity data; S5: Based on the actual attenuation state, separate the coded pattern attenuation line integral value from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the detected material. S6: Reconstruct a three-dimensional image of the material being tested based on the integral value of the attenuation line of the material being tested at each acquisition location, and store the traceability information corresponding to the three-dimensional image.

[0006] As a further aspect of the present invention: the process of determining the trajectory of the radiation source, the detector acquisition position, and the spatial pose of the rotating attenuation array is as follows: The center position and height direction of the material under test are determined based on the three-dimensional geometric data of the material under test. A radiation source trajectory is established around the center position of the material under test and extending along the height direction. The radiation source trajectory intersects with any plane passing through the material under test. Multiple acquisition positions are determined along the trajectory of the radiation source. The position of the radiation source is recorded at each acquisition position. The acquisition position of the detector is determined on the other side of the material being tested. The center line of the ray is obtained by connecting the position of the radiation source and the center position of the detector. The center position of the attenuation array is set on the center line of the ray, and the plane of the attenuation array is set to be parallel to the detector plane. The spatial pose of the attenuation array at each acquisition position is determined according to the ratio of the distance from the radiation source position to the center position of the attenuation array to the distance from the radiation source position to the center position of the detector.

[0007] As a further aspect of the present invention, the process of generating the coded pattern sequence is as follows: The traceability information is converted into a binary sequence and the length of the traceability information is recorded. Zero bits are added to the end of the binary sequence until the total number of binary bits is equal to the product of the number of attenuation units and the number of collection locations. The binary sequence is extracted sequentially according to the number of attenuation units to obtain the binary segment corresponding to each acquisition position. The correspondence between binary bits and attenuation units is established according to the positions of multiple attenuation units. A first attenuation state group and a second attenuation state group are generated based on each binary segment. The attenuation unit corresponding to the binary bit 1 is in a high attenuation state in the first attenuation state group and in a low attenuation state in the second attenuation state group. The attenuation unit corresponding to the binary bit 0 is in a low attenuation state in the first attenuation state group and in a high attenuation state in the second attenuation state group. The first and second attenuation states corresponding to the same binary segment are combined into a coding pattern. Multiple coding patterns are combined according to the order of acquisition positions to obtain a coding pattern sequence.

[0008] As a further aspect of the present invention: the process of setting the attenuation state of multiple attenuation units is as follows: Multiple attenuation units are arranged in a two-dimensional array. An attenuation sheet made of the same attenuation material is set in each attenuation unit. The attenuation sheet includes a first thickness part and a second thickness part, and the thickness of the first thickness part is greater than the thickness of the second thickness part. A rotating component connected to the attenuator is provided in each attenuation unit. The rotating component drives the first thickness part or the second thickness part into the ray path. When the first thickness part enters the ray path, a high attenuation state is formed, and when the second thickness part enters the ray path, a low attenuation state is formed. A position detector is set in each attenuation unit to detect the rotation position of the attenuator. Multiple rotating components are controlled according to the first attenuation state group. The high attenuation state or low attenuation state of each attenuation unit is determined according to the rotation position of the attenuator detected by each position detector, and the determined high attenuation state or low attenuation state is taken as the first actual attenuation state. Multiple rotating components are controlled according to the second attenuation state group. The high attenuation state or low attenuation state of each attenuation unit is determined according to the rotation position of the attenuator detected by each position detector, and the determined high attenuation state or low attenuation state is taken as the second actual attenuation state.

[0009] As a further aspect of the present invention, the process of recording the actual attenuation state and radiation intensity data is as follows: A radiation intensity detector is set at the emission position of the radiation source; when the material being tested and the attenuation array of the rotating plate have not entered the ray path, the air field radiation intensity of each detector pixel is collected according to the acquisition position of each detector, and the corresponding calibrated emission intensity is recorded by the radiation intensity detector. At each acquisition location, the positions of the radiation source, detector, rotating attenuation array, and the material being tested are kept constant, and the radiation source is controlled to emit a single energy ray. Adjust multiple rotating parts according to the first attenuation state group until the first actual attenuation state of each attenuation unit is consistent with the first attenuation state group. Collect the first radiation intensity data through the detector and record the first emission intensity through the radiation intensity detector. Adjust multiple rotating parts according to the second attenuation state group until the second actual attenuation state of each attenuation unit is consistent with the second attenuation state group. Collect the second radiation intensity data through the detector and record the second emission intensity through the radiation intensity detector. The first actual attenuation state and the second actual attenuation state are used together as the actual attenuation state, and the first radiation intensity data and the second radiation intensity data are used together as the radiation intensity data.

[0010] As a further aspect of the present invention, the process of obtaining the integral value of the attenuation line of the tested material is as follows: The first incident intensity is obtained by multiplying the spatial radiation intensity of each detector pixel by the ratio of the first outgoing intensity to the calibrated outgoing intensity; the second incident intensity is obtained by multiplying the spatial radiation intensity by the ratio of the second outgoing intensity to the calibrated outgoing intensity. The attenuation unit that each ray path passes through is determined based on the radiation source location, detector pixel location, and the spatial pose of the attenuation array. Based on the first and second actual attenuation states of the corresponding attenuation units, the radiation intensity data corresponding to the low attenuation state is selected from the first and second radiation intensity data, and the first or second incident intensity corresponding to the same acquisition is selected. Divide the selected incident intensity by the selected radiation intensity data and take the natural logarithm to obtain the total attenuation line integral value of the ray path; multiply the attenuation coefficient of the attenuator material under a single energy ray by the length of the ray path passing through the second thickness section to obtain the attenuation line integral value of the coded pattern; subtract the attenuation line integral value of the coded pattern from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the material being tested. Divide the first radiation intensity data and the second radiation intensity data by the corresponding first incident intensity and the second incident intensity to obtain the first transmittance and the second transmittance; determine the low attenuation state transmittance and the high attenuation state transmittance based on the first actual attenuation state and the second actual attenuation state. The measured state difference is obtained by dividing the low attenuation state transmittance by the high attenuation state transmittance and taking the natural logarithm. The calculated state difference is obtained by multiplying the attenuation coefficient by the difference in the penetration length of the ray path in the first and second thickness sections. The absolute difference between the measured state difference and the calculated state difference is taken as the state deviation.

[0011] As a further aspect of the present invention: the process of storing traceability information corresponding to a three-dimensional image is as follows: The material under test is divided into multiple voxels based on its three-dimensional geometric data. The length of each ray path passing through each voxel is calculated. An initial attenuation coefficient is set for each voxel. The line integral value of each ray path is obtained based on the attenuation coefficient and the corresponding length of each voxel. The updated difference is obtained by subtracting the calculated line integral value from the attenuation line integral value of the material being tested, and the updated ratio is obtained by dividing the calculated state difference by the sum of the calculated state difference and the state deviation. Multiply the update difference, update ratio, and the length of the ray path passing through the corresponding voxel, then divide by the sum of the squares of the lengths of the same ray path passing through each voxel, and add the results to the attenuation coefficient of the corresponding voxel. The attenuation coefficients of each voxel are updated sequentially according to multiple ray paths. After the updates corresponding to multiple ray paths are completed, the calculated line integral value and update difference of each ray path are recalculated. When the absolute value of each update difference does not exceed the preset line integral difference limit or the number of updates reaches the preset number of updates, a three-dimensional image of the detected material is formed based on the attenuation coefficients of each voxel. When the first actual attenuation state is a high attenuation state and the second actual attenuation state is a low attenuation state, a binary bit of 1 is generated; when the first actual attenuation state is a low attenuation state and the second actual attenuation state is a high attenuation state, a binary bit of 0 is generated. The binary bits are arranged according to the attenuation unit position and the acquisition position. The same number of binary bits as the length of the traceability information are extracted according to the arrangement order and converted into traceability information. The traceability information is stored in correspondence with the three-dimensional image of the detected material.

[0012] A radiographic inspection record coding and traceability system, comprising: Acquisition module: Acquires three-dimensional geometric data of the material being tested, determines the trajectory of the radiation source, the acquisition position of the detector, and the spatial pose of the rotating plate attenuation array; Setting module: Generates a sequence of coded patterns based on traceability information, and sets the attenuation state of multiple attenuation units in the attenuation array according to each coded pattern; Recording module: controls the radiation source to move along the radiation source trajectory, records the actual attenuation state at each acquisition location and the radiation intensity data after passing through the tested material; Calculation module: Calculates the integral value of the total attenuation line of each ray path based on the incident intensity and radiation intensity data; Optimization module: Based on the actual attenuation state, the attenuation line integral value of the encoded pattern is separated from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the detected material; Synthetic traceability module: Reconstructs a three-dimensional image of the detected material based on the integral value of the attenuation line of the detected material at each acquisition location, and stores the traceability information corresponding to the three-dimensional image.

[0013] The beneficial effects of this invention compared to the prior art are as follows: This invention avoids directly attaching traceability markers to the surface of the material being tested, reducing occlusion and corresponding reconstruction artifacts caused by local attachments in the detection area. Each ray path has acquisition data corresponding to a low-attenuation state, reducing the possibility of insufficient transmitted rays after the superposition of additional attenuation and material attenuation, and minimizing the extent to which photon count fluctuations are transferred to the line integral result via logarithmic operations. The attenuation component generated by the coded pattern can be determined separately from the attenuation component generated by the material being tested, and the rotational deviation of the attenuation unit and the change in the emission intensity of the radiation source are not easily directly converted into the grayscale of the material structure. After the state deviation participates in the 3D image reconstruction, the update amplitude of different ray paths matches the corresponding acquisition state, reducing the accumulation of attenuation unit state deviation during the reconstruction process. The traceability information is distributed in the coded patterns corresponding to multiple acquisition positions, and the amount of information is no longer limited to a single fixed coded pattern, and it can maintain a correspondence with the reconstructed 3D image. Attached Figure Description

[0014] The invention will now be further described with reference to the accompanying drawings.

[0015] Figure 1 This is a flowchart illustrating a method for tracing and coding radiographic detection records according to the present invention. Figure 2 This is a schematic diagram illustrating the process of storing traceability information in correspondence with three-dimensional images according to the present invention; Figure 3 This is an isometric schematic diagram of the attenuation array of the present invention; Figure 4 This is a schematic diagram of the partial structure and high and low attenuation states of the attenuation unit of the present invention; In the figure: 1. Rotating plate attenuation array; 2. Attenuation unit; 3. Circular attenuator; 4. First thickness part; 5. Second thickness part; 6. Rotating component; 7. Rotation shaft; 8. Angle position detector; 9. Corresponding rectangular area. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figures 1-4 As shown, this invention is a method for tracing and coding radiographic detection records, comprising the following steps: S1: Acquire the three-dimensional geometric data of the material being tested to determine the trajectory of the radiation source, the detector acquisition position, and the spatial pose of the rotating attenuation array; In a preferred embodiment of the present invention, the process of determining the trajectory of the radiation source, the detector acquisition position, and the spatial pose of the rotating attenuation array is as follows: Obtain a 3D design model of the material to be tested, and read the coordinates of the surface vertices and the model coordinate direction. Take the vertical coordinate direction in the model coordinate system as the height direction. Obtain the maximum and minimum coordinates of all surface vertices in each of the three coordinate directions. Calculate half the sum of the maximum and minimum coordinates in each coordinate direction, and combine these three calculation results to determine the center position of the material to be tested. The range between the minimum and maximum coordinates of all surface vertices along the height direction is the height range of the material to be tested.

[0018] Before testing, input the minimum installation distance between the outer surface of the radiation source and the outer surface of the material being tested. Establish a trajectory center axis passing through the center of the material being tested and parallel to the height direction. Calculate the vertical distance from each surface vertex to the trajectory center axis, select the maximum vertical distance, and add the maximum vertical distance to the minimum installation distance to obtain the radius of rotation of the radiation source's trajectory.

[0019] Read the height of the detector's effective imaging surface, the distance from the radiation source to the detector, and the distance from the radiation source to the center of the material being tested. Multiply the height of the detector's effective imaging surface by the distance from the radiation source to the center of the material being tested, and then divide by the distance from the radiation source to the detector to obtain the projected height of the detector's effective imaging surface on the plane containing the center of the material being tested. Use this projected height as the distance the radiation source moves along the height direction for each revolution of its trajectory.

[0020] Starting from the lower end of the height range of the material being tested, the radiation source is controlled to rotate around the central axis of the trajectory according to the radius of rotation. With each rotation, it moves one projected height along the height direction until it reaches the upper end of the height range of the material being tested, forming a spiral radiation source trajectory. Any plane passing through the material being tested refers to a cross-section located within the height range of the material being tested, perpendicular to the height direction, and intersecting with the material.

[0021] Before detection, input the number of sampling locations per week, and divide the circumference angle corresponding to one week into an equal number of angle intervals. Starting from the starting position of the radiation source's trajectory, determine a sampling location after each angle interval, and read the three-dimensional coordinates of the sampling location from the radiation source's trajectory as the radiation source position.

[0022] For each radiation source location, draw a straight line passing through the radiation source location and the center of the material being tested. On the other side of the material being tested, move the pre-input distance from the radiation source to the detector along this straight line to obtain the center position of the detector. The detector plane is perpendicular to this straight line, which is the centerline of the radiation beam.

[0023] Before detection, input the installation distance of the rotating plate attenuation array at the initial acquisition position. Divide this installation distance by the distance from the radiation source to the detector to obtain a fixed distance ratio. For each acquisition position, multiply the distance from the radiation source to the detector by the fixed distance ratio to obtain the distance between the center position of the rotating plate attenuation array and the radiation source position. Move this distance along the ray centerline to determine the center position of the rotating plate attenuation array, and set the plane of the rotating plate attenuation array to be parallel to the detector plane.

[0024] It should be noted that when the radiation source moves around the material being tested along the height direction, transmission data from multiple incident directions can be obtained from the same cross-section, and different height positions can also enter the ray coverage area. The positions of the radiation source, the detector center, and the center of the material being tested form a defined projection geometry, and each detector pixel corresponds to a ray path that can be determined in the three-dimensional geometric data. The center of the rotating attenuation array is located on the ray centerline and parallel to the detector plane. The distance from the radiation source to the rotating attenuation array maintains a fixed ratio with the distance from the radiation source to the detector. The similar triangle relationship in the perspective projection remains unchanged with the acquisition position, and the projection position of the attenuation unit on the detector can be converted using the same ratio. The ray paths formed by each acquisition position pass through the interior of the material being tested, and the attenuation information at different positions inside the material can be determined by transmission data from multiple directions.

[0025] S2: Generate a sequence of coded patterns based on the traceability information, and set the attenuation state of multiple attenuation units in the attenuation array according to each coded pattern; In a preferred embodiment of the present invention, the process of generating the coded pattern sequence is as follows: The traceability information consists of the tested material number, production batch number, testing task number, radiation source number, detector number, and code generation time. The tested material number and production batch number are read from the production record corresponding to the tested material; the testing task number is read from the testing task file for this radiation inspection; the radiation source number and detector number are read from the equipment identification of the radiation source and detector, respectively; and the code generation time is the current time when the code pattern sequence was generated.

[0026] The information should be arranged in the following order: material number, production batch number, testing task number, radiation source number, detector number, and code generation time. Each item should be preceded by its corresponding name, separated by a colon, and adjacent items should be separated by a semicolon, forming a single traceability text. Each number should consist of letters and numbers, without colons or semicolons within the number content. The code generation time should be written in the order of year, month, day, hour, minute, and second.

[0027] An octet conversion format using Unicode character encoding is used to convert each character in the traceability information text into bytes. The bytes are arranged according to their order in the text, and then the binary bits within each byte are read from the most significant bit to the least significant bit. All read binary bits are then concatenated to obtain a binary sequence. The number of binary bits in the sequence before padding with zeros is used as the length of the traceability information.

[0028] The number of attenuation units in the attenuation array and the number of acquisition positions in the radiation source trajectory are read. These two numbers are multiplied to obtain the number of binary bits that the encoded pattern sequence can accommodate. The selected number of attenuation units and acquisition positions must satisfy the condition that their product is not less than the length of the traceability information. The length of the traceability information is subtracted from the number of binary bits that the encoded pattern sequence can accommodate to obtain the number of binary bits that need to be padded. The corresponding number of zero bits are then padded to the end of the binary sequence.

[0029] Using the side of the attenuation array facing the detector as the observation plane, the leftmost attenuation unit in the top row of the two-dimensional array is taken as the first attenuation unit. All attenuation units are arranged in order from left to right within the same row and from top to bottom between rows. Starting from the beginning of the padded binary sequence, the same number of binary bits as the number of attenuation units are read consecutively to obtain a binary segment. The first binary segment corresponds to the first acquisition position, and subsequent binary segments correspond to subsequent acquisition positions in sequence. Each binary bit in a binary segment corresponds to a different attenuation unit according to the arrangement order.

[0030] Read each bit from a binary segment. The attenuation unit corresponding to bit 1 is set to high attenuation in the first attenuation state group and low attenuation in the second attenuation state group. The attenuation unit corresponding to bit 0 is set to low attenuation in the first attenuation state group and high attenuation in the second attenuation state group. Combine the first and second attenuation state groups formed from the same binary segment in sequence to create an encoding pattern. Then arrange the encoding patterns according to the acquisition position order to obtain the encoding pattern sequence.

[0031] Understandably, after the traceability information is converted into a binary sequence, each binary bit can correspond to an attenuation unit with only two states. Multiple attenuation units carry a binary segment at one acquisition location, and multiple acquisition locations sequentially carry the complete binary sequence. The number of binary bits that can be carried is determined by the number of attenuation units and the number of acquisition locations. The padded binary zero is located after the valid binary bits. The length of the traceability information limits the truncation position of the valid binary bits, and encoding and parsing can be completed in reverse order. Each binary bit uses opposite attenuation states in two acquisitions, and the order of states directly represents binary bit one or binary bit zero. At the same time, each attenuation unit has a low attenuation state in both acquisitions. The encoded content is jointly expressed by the state changes at multiple acquisition locations, no longer concentrated in a fixed pattern.

[0032] In this embodiment, the encoding pattern is an ordered combination of the first attenuation state group and the second attenuation state group corresponding to the same acquisition position, formed according to the order of acquisition. It does not represent a single attenuation state group presented by the attenuation array during a single acquisition. An encoding pattern is executed twice consecutively at the corresponding acquisition position, the first attenuation state group is executed the first time, and the second attenuation state group is executed the second time.

[0033] It should be noted that the working principle of the attenuation array includes: The attenuation array 1 is formed by arranging multiple attenuation units 2 in a two-dimensional manner. Each attenuation unit 2 contains a circular attenuator 3, which is made of the same attenuation material. The thickness of the first thickness portion 4 is greater than the thickness of the second thickness portion 5. A rotating component 6 is connected to the center of the circular attenuator 3 via a rotating shaft 7, which is perpendicular to the plane of the circular attenuator 3. An angle position detector 8 is mounted on the rotating shaft 7. The corresponding rectangular area 9 represents the area through which the ray passes corresponding to the attenuation unit 2, and its boundary is marked with a dashed line in the figure. After the traceability information is pre-converted into an encoded pattern, the target attenuation state of each attenuation unit 2 is determined according to the encoded pattern. The rotating component 6 drives the circular attenuator 3 to rotate via the rotating shaft 7. When the first thickness portion 4 covers the corresponding rectangular area 9, a high attenuation state is formed; when the second thickness portion 5 covers the corresponding rectangular area 9, a low attenuation state is formed. The angle position detector 8 detects the actual rotation angle and confirms the actual attenuation state of the attenuation unit 2 based on the rotation position range of the actual rotation angle. If the actual attenuation state is inconsistent with the target attenuation state, the rotating component 6 is readjusted. Exposure and acquisition are performed after the actual attenuation state of all attenuation units 2 is consistent with the target attenuation state. Keeping the ray path unchanged at the same acquisition location, execute two complementary attenuation state groups sequentially and acquire data separately, recording the actual attenuation state and the corresponding radiation intensity data.

[0034] It is worth noting that the front view is a view obtained by observing the circular attenuator 3 along a direction perpendicular to the plane of the circular attenuator 3. Figure 4 The two front views at the bottom center show the state of the same circular attenuator 3 before and after rotation. The arrow between the two front views indicates that the circular attenuator 3 rotates around the rotation axis 7, and the rotating component 6 drives the first thickness part 4 and the second thickness part 5 to change position via the rotation axis 7. The corresponding rectangular area 9 represents the area through which the ray corresponding to the attenuation unit 2 passes, and its position remains unchanged and does not rotate with the circular attenuator 3. In the left front view, the first thickness part 4 covers the corresponding rectangular area 9, forming a high attenuation state; after the circular attenuator 3 rotates to the position corresponding to the right front view, the second thickness part 5 covers the corresponding rectangular area 9, forming a low attenuation state.

[0035] S3: Control the radiation source to move along the radiation source trajectory and record the actual attenuation state and radiation intensity data after passing through the material being tested at each acquisition location; In a preferred embodiment of the present invention, the process of setting the attenuation state of multiple attenuation units is as follows: Read the width and height of the effective ray passage surface of the attenuation array, and read the number of rows and columns of the two-dimensional array. Divide the width of the effective ray passage surface equally according to the number of columns, and divide the height of the effective ray passage surface equally according to the number of rows. The rectangular area enclosed by adjacent width and height boundaries is considered as an attenuation unit. Each attenuation unit corresponds to a binary bit in the encoding pattern in a left-to-right order within the same row and a top-to-bottom order between rows.

[0036] Each attenuation unit contains a circular attenuator. The attenuator is integrally formed from the same attenuation material, with one portion retaining a first thickness and the other portion processed to a second thickness, the first thickness being greater than the second thickness. The dimensions of both the first and second thickness portions on the attenuator plane are larger than the rectangular area of ​​the corresponding attenuation unit.

[0037] A rotating component is connected to the center of the attenuator, with its rotation axis perpendicular to the attenuator plane. When the attenuator rotates, either a first or second thickness portion covers the rectangular area of ​​the attenuator unit. A high attenuation state is achieved when the first thickness portion covers the rectangular area, and a low attenuation state is achieved when the second thickness portion covers the rectangular area.

[0038] An angle position detector is installed on the rotation axis of the rotating component. The attenuator is rotated until one side boundary of the first thickness portion begins to leave the rectangular area of ​​the attenuation unit, obtaining the first angle at this point. The attenuator is then rotated in the opposite direction until the other side boundary of the first thickness portion begins to leave the rectangular area, obtaining the second angle. The area between the first and second angles constitutes the first rotation position range. The same process is used to obtain the second rotation position range when the second thickness portion completely covers the rectangular area. The first rotation position range corresponds to the high attenuation state, and the second rotation position range corresponds to the low attenuation state.

[0039] Read the target state from the first attenuation state group. When the target state is a high attenuation state, rotate the rotating component to the midpoint of the first rotation position range; when the target state is a low attenuation state, rotate the rotating component to the midpoint of the second rotation position range. When the position detector output angle is within the first rotation position range, it is determined to be a high attenuation state; when the output angle is within the second rotation position range, it is determined to be a low attenuation state, and the result is the first actual attenuation state. After completing the first acquisition, perform the same operation according to the second attenuation state group, and the result is the second actual attenuation state.

[0040] In another preferred embodiment of the present invention, the process of recording the actual attenuation state and radiation intensity data is as follows: The radiation source is a radiation source with fixed radiation energy. A radiation intensity detector is fixedly connected to the radiation source, and its detection surface is located in a fixed region at the edge of the emitted radiation beam, outside the effective imaging path of the detector. The integrated intensity obtained by the radiation intensity detector during a single exposure is the emitted intensity of that exposure.

[0041] A field acquisition is performed before the material under test and the attenuation array enter the X-ray path. The radiation source arrives at each acquisition position sequentially, and the detector arrives at the corresponding detector acquisition position. The radiation source emits X-rays according to the X-ray energy and exposure time used in the formal test. The intensity values ​​of each pixel obtained by the detector during one exposure are taken as the field radiation intensity of the corresponding pixel, and the integrated intensity obtained by the radiation intensity detector during the same exposure is the calibrated emission intensity of the corresponding acquisition position.

[0042] All acquisition locations are arranged according to the movement order of the radiation source along its trajectory, and all coded patterns are arranged according to their order within the coded pattern sequence. Acquisition locations and coded patterns that are in the same position correspond to each other. The number of coded patterns is the same as the number of acquisition locations, and each coded pattern is used at its corresponding acquisition location.

[0043] After the radiation source reaches the first acquisition position, the first coded pattern is read from the coded pattern sequence, and the first and second attenuation state groups are obtained from this coded pattern. Keeping the positions of the radiation source, detector, rotating attenuation array, and the material being detected unchanged, the target angles of each rotating component are set according to the first attenuation state group. If the output angle of the position detector is not within the rotation position range corresponding to the target state, the corresponding rotating component is rotated back to the middle angle of that rotation position range.

[0044] Once all the first actual attenuation states are consistent with the first attenuation state group, the intensity values ​​of each pixel obtained by the detector during one exposure period constitute the first radiation intensity data, and the integrated intensity obtained by the radiation intensity detector during the same exposure period is the first outgoing intensity.

[0045] After the first exposure, the target angles of each rotating component are set according to the second attenuation state group in the same coded pattern. After all the second actual attenuation states are consistent with the second attenuation state group, the pixel intensity values ​​obtained by the detector during the second exposure constitute the second radiation intensity data, and the integrated intensity obtained by the radiation intensity detector during the same exposure is the second emitted intensity.

[0046] After two exposures at the first acquisition location, the radiation source moves to the second acquisition location, reads the second coded pattern from the coded pattern sequence, and performs two exposures according to the first and second attenuation state groups in the second coded pattern. Subsequent acquisition locations are processed in the same manner until the last coded pattern in the coded pattern sequence is acquired. The first and second actual attenuation states are combined to form the actual attenuation state, and the first and second radiation intensity data are combined to form the radiation intensity data.

[0047] It should be noted that the same attenuating material has the same attenuation coefficient when the ray energy remains constant. When the length of the ray passing through the material changes, the attenuation line integral changes with the passing length. The first and second thickness sections use the same material but have different thicknesses. After entering the same ray path, the two thickness sections respectively form a high attenuation state and a low attenuation state. The rotating component changes the rotation position of the attenuator, allowing switching between the two attenuation states. After each attenuation unit is equipped with a rotating component, each position in the two-dimensional array can independently form a high attenuation state or a low attenuation state. The position detector reads the rotation position that the attenuator has reached. There is a definite correspondence between the rotation position and the coverage area of ​​the two thickness sections. The first and second actual attenuation states originate from the actual position of the attenuator and are not direct replacements for control commands.

[0048] The open-field radiation intensity represents the intensity of the radiation received by each detector pixel under the same acquisition geometry, before the radiation passes through the material being tested and the attenuation array. The radiation intensity detector continuously detects a fixed radiation region at the radiation source's emission position during both open-field acquisition and material detection. The change between the calibrated emission intensity and the actual acquisition emission intensity characterizes the change in radiation source output between the two exposures. The coded pattern sequence corresponds to the acquisition positions in the same order. After the radiation source reaches an acquisition position, the corresponding coded pattern is read, and two acquisitions are completed under the condition that the positions of the radiation source, detector, attenuation array, and material being tested remain unchanged. The material being tested and the radiation path remain the same in both acquisitions; the change is limited to the thickness state of the attenuation unit. The first and second radiation intensity data correspond to the first and second actual attenuation states, respectively.

[0049] S4: Obtain the integral value of the total attenuation line of each ray path based on the incident intensity and radiation intensity data; S5: Based on the actual attenuation state, separate the coded pattern attenuation line integral value from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the detected material. In another preferred embodiment of the present invention, the process of obtaining the integral value of the attenuation line of the tested material is as follows: For a single detector pixel, the spatial radiation intensity acquired by that pixel at the same detector acquisition location is read. The first emitted intensity is divided by the calibrated emitted intensity, and the resulting ratio is multiplied by the spatial radiation intensity to obtain the first incident intensity. The second emitted intensity is divided by the calibrated emitted intensity, and the resulting ratio is multiplied by the spatial radiation intensity to obtain the second incident intensity.

[0050] Connect the radiation source position at the current acquisition location with the detector pixel center position to form the ray path corresponding to that detector pixel. Calculate the intersection point of the ray path with the plane of the attenuation array. Compare the planar coordinates of the intersection point with the width and height boundaries of each attenuation unit. The rectangular area enclosed by the adjacent width and height boundaries of the intersection point corresponds to the attenuation unit traversed by the ray path.

[0051] The first and second actual attenuation states of the attenuation unit are read. When the first actual attenuation state is a low attenuation state, the intensity value of the detector pixel and the first incident intensity are selected from the first radiation intensity data; when the second actual attenuation state is a low attenuation state, the intensity value of the detector pixel and the second incident intensity are selected from the second radiation intensity data. The low attenuation state is determined by the output angle of the position detector, not by comparing the values ​​of the two radiation intensity data.

[0052] Divide the selected incident intensity by the selected detector pixel intensity value, and take the natural logarithm of the resulting ratio to obtain the total attenuation line integral value of the ray path.

[0053] A calibration plate of known thickness is made using the same material as the attenuator. The intensity of the attenuator without the calibration plate and with the calibration plate are measured using a single-energy ray. The attenuation coefficient of the attenuator material is obtained by dividing the intensity without the calibration plate by the intensity with the calibration plate, taking the natural logarithm of the ratio, and then dividing by the length of the ray path through the calibration plate.

[0054] Calculate the intersection points of the ray path with the incident and exit surfaces of the second thickness section. The distance between the two intersection points is the length of the ray path passing through the second thickness section. Multiply this length by the attenuation coefficient to obtain the attenuation line integral value of the coded pattern. Subtract the attenuation line integral value of the coded pattern from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the material being tested.

[0055] The first transmittance is obtained by dividing the intensity value of the detector pixel in the first radiation intensity data by the first incident intensity; the second transmittance is obtained by dividing the intensity value of the detector pixel in the second radiation intensity data by the second incident intensity. The transmittance in the low-attenuation state and the transmittance in the high-attenuation state are determined according to the first and second actual attenuation states. The measured state difference is obtained by dividing the low-attenuation state transmittance by the high-attenuation state transmittance and taking the natural logarithm. The calculated state difference is obtained by multiplying the difference in the penetration length of the ray path within the first and second thickness portions by the attenuation coefficient. The absolute difference between the two state differences is the state deviation.

[0056] It is worth noting that the intensity of the radiation after passing through multiple objects follows an exponential decay relationship. After taking the natural logarithm of the ratio of incident intensity to transmitted intensity, the attenuation caused by different objects changes from a product relationship to an additive relationship of line integrals. The spatial radiation intensity, after being corrected for the output intensity ratio, corresponds to the incident intensity at the time of formal acquisition. The incident intensity and radiation intensity data can form the total attenuation line integral value of the radiation path, including the material being tested and the attenuator. In the two complementary attenuation states, there must be a low attenuation state, which corresponds to the second thickness section. The passage length of the radiation path within the second thickness section and the material attenuation coefficient can determine the attenuation line integral value of the coded pattern. Subtracting this value from the total attenuation line integral value of the radiation path yields the attenuation line integral value of the material being tested. The attenuation of the material being tested is the same in the two acquisitions of the same radiation path. After dividing the transmittance of the low attenuation state by the transmittance of the high attenuation state, the attenuation components of the material being tested cancel each other out, and the remaining change corresponds to the attenuation difference between the two thickness sections. The deviation between the measured state difference and the state difference calculated according to the actual passage length forms the state deviation, which reflects the difference between the actual acquisition state and the geometrically calculated state of the radiation path.

[0057] S6: Reconstruct a three-dimensional image of the material being tested based on the integral value of the attenuation line of the material being tested at each acquisition location, and store the traceability information corresponding to the three-dimensional image.

[0058] In a preferred embodiment of the present invention, the process of storing traceability information corresponding to a three-dimensional image is as follows: Read the width and height of the detector pixels on the detector plane, and convert them to the plane containing the center of the material being detected. During conversion, multiply the detector pixel width or height by the distance from the radiation source to the center of the material being detected, and then divide by the distance from the radiation source to the detector. Select the smaller of the two converted values ​​as the voxel side length.

[0059] The space containing the 3D geometry of the material under test is divided into multiple cubes according to the voxel side lengths. The cube whose center is located inside the geometric boundary of the material under test is taken as a voxel. The intersection points of a ray path with the surface of each voxel are calculated, and the distance between two intersection points is the length of the ray path passing through the corresponding voxel.

[0060] The initial attenuation coefficient of each voxel is set to zero. For a ray path, the attenuation coefficient of each voxel along the ray path is multiplied by the corresponding length of travel, and the products are summed to obtain the calculated line integral value. The updated difference is obtained by subtracting the calculated line integral value from the attenuation line integral value of the detected material. The updated ratio is obtained by dividing the calculated state difference by the sum of the calculated state difference and the state deviation.

[0061] For each voxel traversed by the ray path, multiply the update difference, update ratio, and corresponding traversal length, then divide by the sum of the squares of the ray path's traversal lengths across all corresponding voxels. Add the result to the voxel's attenuation coefficient. After updating the voxels corresponding to one ray path, process the next ray path.

[0062] Before detection, the input line integral difference limit and maximum update count are set. After updating all ray paths, the update count is increased by one, and the calculated line integral value and update difference for each ray path are recalculated. The update ends when the absolute value of each update difference does not exceed the line integral difference limit; if an update difference exceeds the line integral difference limit but the update count is less than the maximum update count, the update continues; the update ends when the maximum update count is reached. The attenuation coefficient of each voxel at the end of the update is used as the voxel image value, and a 3D image is formed according to the spatial position of each voxel.

[0063] The actual attenuation state is read sequentially according to the acquisition location, and within the same acquisition location, the first and second actual attenuation states are read sequentially according to the attenuation unit. A binary bit of '1' is obtained when the state sequence is high attenuation and low attenuation, and a binary bit of '0' is obtained when the state sequence is low attenuation and high attenuation. These binary bits are then concatenated sequentially. A number of binary bits equal to the length of the traceability information are truncated from the starting position and converted into traceability information text according to the character encoding rules used in Example 2. The data portion of the 3D image file is written with the voxel image values, and the additional information portion is written with the traceability information text.

[0064] It should be noted that the attenuation line integral value of the detected material along a ray path is equal to the sum of the products of the attenuation coefficients of each voxel traversed by the ray path and their corresponding traversal lengths. Ray paths formed by multiple acquisition positions impose mutual constraints on different voxels. The update difference between the calculated line integral value and the attenuation line integral value of the detected material can be distributed to each voxel along the ray path, and the traversal length limits the update share of each voxel in that ray path. The update ratio formed by calculating the state difference and state deviation introduces the degree of attenuation unit state deviation into the voxel update; when the state deviation increases, the update amount transmitted to the voxel by the corresponding ray path decreases accordingly. After repeated updates by multiple ray paths, the attenuation coefficients of each voxel form a three-dimensional image of the detected material. The order of the first and second actual attenuation states is reversed according to the binary bit mapping relationship during encoding. The binary sequence is restored according to the attenuation unit position and acquisition position, and then the padding content is removed according to the traceability information length. The resulting traceability information corresponds to the three-dimensional image formed by the same ray data.

[0065] This invention transfers traceability information from the surface of the material being inspected to the radiation propagation process. It separates the two types of attenuation by utilizing the relationship that while the encoded state changes at the same acquisition location, the attenuation of the inspected material remains constant. The encoded content is distributed across multiple acquisition locations, no longer concentrated in a single fixed pattern. Each attenuation unit experiences both a high-attenuation state and a low-attenuation state in two acquisitions, with the state sequence representing the traceability information. The data corresponding to the low-attenuation state is used for material imaging. The actual position of the attenuation unit and changes in the radiation source output are simultaneously entered into the data processing. Additional attenuation generated by the encoding is not directly incorporated into the material attenuation, and state deviations do not participate in image updates of equal magnitude according to the normal radiation path. Therefore, it is possible to retain the traceability information corresponding to the current inspection while completing the three-dimensional imaging of the material.

[0066] A radiographic inspection record coding and traceability system, comprising: Acquisition module: Acquires three-dimensional geometric data of the material being tested, determines the trajectory of the radiation source, the acquisition position of the detector, and the spatial pose of the rotating plate attenuation array; Setting module: Generates a sequence of coded patterns based on traceability information, and sets the attenuation state of multiple attenuation units in the attenuation array according to each coded pattern; Recording module: controls the radiation source to move along the radiation source trajectory, records the actual attenuation state at each acquisition location and the radiation intensity data after passing through the tested material; Calculation module: Calculates the integral value of the total attenuation line of each ray path based on the incident intensity and radiation intensity data; Optimization module: Based on the actual attenuation state, the attenuation line integral value of the encoded pattern is separated from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the detected material; Synthetic traceability module: Reconstructs a three-dimensional image of the detected material based on the integral value of the attenuation line of the detected material at each acquisition location, and stores the traceability information corresponding to the three-dimensional image.

[0067] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for tracing and coding radiographic inspection records, characterized in that, Includes the following steps: S1: Acquire the three-dimensional geometric data of the material being tested to determine the trajectory of the radiation source, the detector acquisition position, and the spatial pose of the rotating attenuation array; S2: Generate a sequence of coded patterns based on the traceability information, and set the attenuation state of multiple attenuation units in the attenuation array according to each coded pattern; S3: Control the radiation source to move along the radiation source trajectory and record the actual attenuation state and radiation intensity data after passing through the material being tested at each acquisition location; S4: Obtain the integral value of the total attenuation line of each ray path based on the incident intensity and radiation intensity data; S5: Based on the actual attenuation state, separate the coded pattern attenuation line integral value from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the detected material. S6: Reconstruct a three-dimensional image of the material being tested based on the integral value of the attenuation line of the material being tested at each acquisition location, and store the traceability information corresponding to the three-dimensional image.

2. The method for tracing and coding radiographic detection records according to claim 1, characterized in that, The process of determining the trajectory of the radiation source, the detector's acquisition position, and the spatial pose of the rotating attenuation array is as follows: The center position and height direction of the material under test are determined based on the three-dimensional geometric data of the material under test. A radiation source trajectory is established around the center position of the material under test and extending along the height direction. The radiation source trajectory intersects with any plane passing through the material under test. Multiple acquisition positions are determined along the trajectory of the radiation source. The position of the radiation source is recorded at each acquisition position. The acquisition position of the detector is determined on the other side of the material being tested. The center line of the ray is obtained by connecting the position of the radiation source and the center position of the detector. The center position of the attenuation array is set on the center line of the ray, and the plane of the attenuation array is set to be parallel to the detector plane. The spatial pose of the attenuation array at each acquisition position is determined according to the ratio of the distance from the radiation source position to the center position of the attenuation array to the distance from the radiation source position to the center position of the detector.

3. The method for tracing and coding radiographic detection records according to claim 1, characterized in that, The process of generating the coded pattern sequence is as follows: The traceability information is converted into a binary sequence and the length of the traceability information is recorded. Zero bits are added to the end of the binary sequence until the total number of binary bits is equal to the product of the number of attenuation units and the number of collection locations. The binary sequence is extracted sequentially according to the number of attenuation units to obtain the binary segment corresponding to each acquisition position. The correspondence between binary bits and attenuation units is established according to the positions of multiple attenuation units. A first attenuation state group and a second attenuation state group are generated based on each binary segment. The attenuation unit corresponding to the binary bit 1 is in a high attenuation state in the first attenuation state group and in a low attenuation state in the second attenuation state group. The attenuation unit corresponding to the binary bit 0 is in a low attenuation state in the first attenuation state group and in a high attenuation state in the second attenuation state group. The first and second attenuation states corresponding to the same binary segment are combined into a coding pattern. Multiple coding patterns are combined according to the order of acquisition positions to obtain a coding pattern sequence.

4. The method for tracing and coding radiographic detection records according to claim 1, characterized in that, The process of setting the attenuation state of multiple attenuation units is as follows: Multiple attenuation units are arranged in a two-dimensional array. An attenuation sheet made of the same attenuation material is set in each attenuation unit. The attenuation sheet includes a first thickness part and a second thickness part, and the thickness of the first thickness part is greater than the thickness of the second thickness part. A rotating component connected to the attenuator is provided in each attenuation unit. The rotating component drives the first thickness part or the second thickness part into the ray path. When the first thickness part enters the ray path, a high attenuation state is formed, and when the second thickness part enters the ray path, a low attenuation state is formed. A position detector is set in each attenuation unit to detect the rotation position of the attenuator. Multiple rotating parts are controlled according to the first attenuation state group. The high attenuation state or low attenuation state of each attenuation unit is determined according to the rotation position of the attenuator detected by each position detector, and the determined high attenuation state or low attenuation state is taken as the first actual attenuation state. Multiple rotating components are controlled according to the second attenuation state group. The high attenuation state or low attenuation state of each attenuation unit is determined based on the rotation position of the attenuator detected by each position detector, and the determined high attenuation state or low attenuation state is taken as the second actual attenuation state.

5. The method for tracing and coding radiographic detection records according to claim 1, characterized in that, The process of recording the actual attenuation state and radiation intensity data is as follows: A radiation intensity detector is set at the emission position of the radiation source; when the material being tested and the attenuation array of the rotating plate have not entered the ray path, the air field radiation intensity of each detector pixel is collected according to the acquisition position of each detector, and the corresponding calibrated emission intensity is recorded by the radiation intensity detector. At each acquisition location, the positions of the radiation source, detector, rotating attenuation array, and the material being tested are kept constant, and the radiation source is controlled to emit a single energy ray. Adjust multiple rotating parts according to the first attenuation state group until the first actual attenuation state of each attenuation unit is consistent with the first attenuation state group. Collect the first radiation intensity data through the detector and record the first emission intensity through the radiation intensity detector. Adjust multiple rotating parts according to the second attenuation state group until the second actual attenuation state of each attenuation unit is consistent with the second attenuation state group. Collect the second radiation intensity data through the detector and record the second emission intensity through the radiation intensity detector. The first actual attenuation state and the second actual attenuation state are used together as the actual attenuation state, and the first radiation intensity data and the second radiation intensity data are used together as the radiation intensity data.

6. The method for tracing and coding radiographic detection records according to claim 5, characterized in that, The process of obtaining the integral value of the attenuation line of the tested material is as follows: The first incident intensity and the second incident intensity are obtained based on the airfield radiation intensity, the calibrated outgoing intensity, the first outgoing intensity and the second outgoing intensity; Based on the attenuation unit through which the ray path passes and the first and second actual attenuation states, the radiation intensity data and incident intensity corresponding to the low attenuation state are selected to obtain the total attenuation line integral value of the ray path. The attenuation line integral value of the encoded pattern is obtained based on the attenuation coefficient and the length of the ray path within the second thickness section. The attenuation line integral value of the detected material is then separated from the total attenuation line integral value of the ray path. The measured state difference is obtained based on the transmittance corresponding to the high attenuation state and the low attenuation state, and the calculated state difference is obtained based on the difference in the through length of the two thickness sections. The absolute difference between the two is taken as the state deviation.

7. The method for tracing and coding radiographic detection records according to claim 6, characterized in that, The process of storing traceability information in correspondence with 3D images is as follows: Based on the three-dimensional geometric data, voxels are divided, and the line integral value is calculated based on the penetration length of each ray path within the voxel and the initial attenuation coefficient of the voxel. The update ratio is obtained by combining the update difference between the integral value of the decay line of the tested material and the integral value of the calculated line, and by combining the calculated state difference and state deviation. The attenuation coefficients of each voxel are updated according to the update difference, update ratio, and length of passage until the update difference meets the preset line integral difference limit or reaches the preset number of updates. A three-dimensional image is then formed based on the updated attenuation coefficients. Binary bits are generated according to the arrangement order of the first and second actual attenuation states. The binary bits are arranged according to the position of the attenuation unit and the acquisition position. The bits are then truncated and converted according to the length of the traceability information. The resulting traceability information is stored in correspondence with the three-dimensional image.

8. A radiographic inspection record coding and traceability system, characterized in that, include: Acquisition module: Acquires three-dimensional geometric data of the material being tested, determines the trajectory of the radiation source, the acquisition position of the detector, and the spatial pose of the rotating plate attenuation array; Setting module: Generates a sequence of coded patterns based on traceability information, and sets the attenuation state of multiple attenuation units in the attenuation array according to each coded pattern; Recording module: controls the radiation source to move along the radiation source trajectory, records the actual attenuation state at each acquisition location and the radiation intensity data after passing through the tested material; Calculation module: Calculates the integral value of the total attenuation line of each ray path based on the incident intensity and radiation intensity data; Optimization module: Based on the actual attenuation state, the attenuation line integral value of the encoded pattern is separated from the total attenuation line integral value of the ray path to obtain the attenuation line integral value of the detected material; Synthetic traceability module: Reconstructs a three-dimensional image of the detected material based on the integral value of the attenuation line of the detected material at each acquisition location, and stores the traceability information corresponding to the three-dimensional image.

Images