High-speed chopper wheel scanning imaging method

Abstract

The invention relates to the technical field of radiation imaging, and discloses a high-speed chopper wheel scanning imaging method, which comprises core structure configuration and imaging operation steps, and specifically comprises the following steps: core structure configuration: (a) preparing an annular chopper wheel by adopting a lead material with the density equal to or higher than that of a steel plate, four equidistant beam outlets are uniformly distributed in the peripheral direction of the chopper wheel, penetrate through the inner side and the outer side of the chopper wheel and are used for collimating X-rays; (b) an X light source is fixedly arranged in the annular central area of the chopper wheel, and a transmitting end faces a beam outlet; and (c) a detector is fixedly arranged outside the chopping wheel, and the receiving surface of the detector corresponds to the emergent direction of the beam outlet and is used for receiving X-ray energy reflected by the scanned object. According to the high-speed chopper wheel scanning imaging method, by optimizing the chopper wheel structure design and the imaging process, synchronous improvement of energy collection efficiency, imaging precision and scanning speed is achieved, the imaging algorithm is simplified, and the core pain point in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of radiation imaging technology, specifically a high-speed chopper wheel scanning imaging method, which is applied to the detection of information such as the internal material density of the scanned object. It is suitable for radiation imaging-related scenarios such as industrial inspection and security investigation, and belongs to the category of nuclear radiation measurement technology in the high-end equipment manufacturing industry. Background Technology

[0002] In the field of radiation imaging, the detection of the internal material density of an object is a core application requirement. Currently, the mainstream technology used in the industry is backscatter imaging, which achieves imaging by receiving X-ray energy reflected based on the Compton effect through a detector. Its core principle is to use the reflected signal after the interaction between X-rays and the internal material of an object to infer the internal structure and density distribution of the object. Due to its non-contact detection advantage, it has found certain applications in related fields.

[0003] However, existing backscatter imaging technology suffers from numerous insurmountable drawbacks, severely impacting detection effectiveness and efficiency. First, the reflected X-ray energy is extremely weak, resulting in low detector signal acquisition efficiency and necessitating complex algorithms for signal enhancement. This not only increases data processing complexity but also easily introduces interference noise. Second, the energy spectrum imaging resolution is low, typically only reaching ≤0.8 mm, leading to blurry images and difficulty in accurately identifying fine internal structures and density differences within objects. Third, the complex imaging algorithms further increase equipment development and maintenance costs, and the slow scanning speed (≤10 lines per second) fails to meet batch detection requirements. Furthermore, the irregular design of the chopper's beam aperture in existing technologies results in uneven energy acquisition, further exacerbating image blurring and insufficient resolution.

[0004] Therefore, a high-speed chopper wheel scanning imaging method is proposed to solve the above-mentioned problems. Summary of the Invention

[0005] (a) Technical problems to be solved To address the technical challenges of existing backscatter imaging technologies, such as weak X-ray energy, low energy spectrum imaging resolution, blurred images, complex imaging algorithms, slow scanning speed, and uneven energy acquisition caused by irregular beam apertures of existing choppers, this invention provides a high-speed chopper scanning imaging method. By optimizing the chopper structure design and imaging process, it achieves simultaneous improvements in energy acquisition efficiency, imaging accuracy, and scanning speed, simplifies the imaging algorithm, and solves the core pain points of existing technologies.

[0006] (II) Technical Solution The technical solution of the present invention to solve the above-mentioned technical problems is as follows: Core structural configuration: (a) Chopper structure: The ring collimator is made of high-density lead material. The core innovation is that four equidistant beam outlets are set on the ring body. The spacing between adjacent beam outlets is uniform, which ensures that the chopper can stably collect 4-line flying point X-ray energy data in one rotation. The faster the rotation speed, the higher the scanning imaging efficiency. The size of the beam outlet can be adjusted according to the accuracy requirements. The smaller the aperture, the higher the imaging resolution. The structure solves the problem of uneven energy collection.

[0007] (b) Installation of light source and detector: The X-ray source is fixedly built into the center of the chopper ring to shorten the X-ray transmission path and reduce energy loss; the detector is fixedly placed outside the chopper and precisely corresponds to the exit direction of the beam outlet to ensure effective reception of reflected X-ray energy.

[0008] (c) Positioning detection structure: The photoelectric switch is fixed near the chopper wheel as a beam outlet position identification device, which captures the position data of the beam outlet in real time during the rotation process, providing a basis for the accurate calculation of the interval time t.

[0009] (d) Placement of the object to be inspected: The object to be scanned is dynamically placed near the detector and passes through the detection area at a constant speed with the conveyor mechanism, which is suitable for batch detection scenarios.

[0010] Imaging operation steps: S1. Timing calibration: When the chopper rotates at high speed, the photoelectric switch transmits the detected beam outlet position data to the computer. Based on the equidistant characteristics of the rotation speed and the beam outlet, the computer calculates the interval time t between two adjacent beam outlets.

[0011] S2. Energy Acquisition: Within the time interval t, the detector integrates and acquires the X-ray energy reflected from the flying point through each pixel. By using multi-line integration acquisition, the problem of weak X-ray energy is solved, and the signal strength is improved.

[0012] S3. Data Processing: The computer filters and denoises the energy data within time t, then merges them into a vertical line of energy data. An array is formed by n merged data, simplifying traditional complex algorithms and avoiding image blurring.

[0013] S4. Density Reconstruction: By utilizing the large difference in energy fluctuations between adjacent pixels of the detector, the energy distribution differences are analyzed through image processing to accurately reconstruct the internal density information of the scanned object, thereby improving the efficiency of material identification.

[0014] The beneficial effects of this invention are: Solving the problem of weak energy: By integrating data acquisition within time t and incorporating an X-ray source, the energy acquisition efficiency is improved by 30% compared to existing technologies, without the need for complex signal enhancement algorithms; Improved imaging accuracy: With four equidistant beam exits and an adjustable small beam aperture design, the energy spectrum imaging resolution reaches 0.1-0.3 mm, the image is clear, and the density detection error is ≤5%, which is superior to existing technologies; Improved scanning speed: High-speed rotation of the chopper wheel + 4-line acquisition design per revolution, scanning speed ≥ 40 lines per second, suitable for batch testing, solving the pain point of slow scanning in existing technologies; Simplified imaging algorithm: By filtering and merging energy data into a vertical line, the imaging algorithm is greatly simplified, reducing equipment cost and maintenance difficulty; Significant structural advantages: The regular and equidistant beam exits, unlike existing irregular aperture designs, result in more uniform energy collection, further improving imaging stability and material identification efficiency.

[0015] This high-speed chopper-wheel scanning imaging method has the advantages of high energy harvesting efficiency, high imaging resolution, fast scanning speed, simple and easy-to-implement algorithm, stable and reliable structure, and strong scene adaptability.

[0016] Based on the above technical solution, the present invention can be further improved as follows.

[0017] Furthermore, the spacing error of the four beam exits is ≤ ±0.1 mm, and the beam aperture is 0.1-1 mm. The smaller the aperture, the higher the imaging resolution. Among them, the 0.1-0.3 mm aperture is suitable for high-resolution detection, and the 0.4-1 mm aperture is suitable for conventional detection.

[0018] The beneficial effects of adopting the above-mentioned further solutions are that by precisely controlling the uniformity of the beam aperture spacing, the phenomenon of excessively strong or weak energy acquisition in some areas can be avoided, ensuring uniform grayscale in the imaging; the aperture gradient design achieves full coverage of scenarios from high precision to routine detection, and can adapt to different detection needs without replacing core components, thus improving the versatility of the equipment.

[0019] Furthermore, the chopper wheel rotates at a speed of 500-2000 revolutions per minute, and the rotation speed is positively correlated with the scanning imaging speed. The maximum scanning speed is ≥40 lines per second, which is a significant improvement over the existing technology.

[0020] The beneficial effects of adopting the above-mentioned further solution are that the wide speed adjustment range can match detection scenarios with different conveying speeds (such as high-speed conveying on industrial assembly lines and slow passage of personnel in security passages), and the scanning speed of up to 40 lines per second is 4 times higher than the existing technology (≤10 lines per second), which greatly shortens the batch detection time and increases the detection throughput.

[0021] Furthermore, the photoelectric switch has a detection accuracy of 0.001 mm, a signal transmission delay time of ≤5 ms, and an interval time t calculation accuracy of ≤±0.002 seconds.

[0022] The advantages of adopting the above-mentioned further scheme are that the ultra-high detection accuracy and low signal delay ensure that the beam exit position identification is without deviation, and the accurate calculation of the interval time t provides a strict timing reference for the detector integration acquisition, avoiding signal loss or superposition interference caused by the misalignment of energy acquisition and beam exit timing, and ensuring the accuracy of imaging data.

[0023] Furthermore, within the specified time interval t, the number of X-ray energy lines collected by the detector through integration is ≥100, and the energy collection efficiency is improved by 30% compared with the prior art.

[0024] The beneficial effect of adopting the above-mentioned further scheme is that the multi-line integration acquisition mode significantly improves the detection rate of reflected X-rays by accumulating weak energy signals. The 30% efficiency improvement directly reduces the dependence on the power of the X-ray source, which saves energy, reduces radiation dose, and improves the safety of equipment use.

[0025] Furthermore, the detector is an X-ray dedicated array structure with a pixel count of no less than 1024×1024 and an energy spectrum imaging resolution of 0.1-0.3 mm.

[0026] The beneficial effect of adopting the above-mentioned further solution is that the high-pixel array provides sufficient acquisition units, and with the ultra-high resolution of 0.1-0.3 mm, it can accurately capture the subtle density differences inside the object, solving the pain point that existing technologies cannot identify fine structures.

[0027] Furthermore, the data filtering process employs a simplified algorithm, replacing the complex algorithms of existing technologies with a single-step filtering and denoising method combined with direct merging of energy data, thereby avoiding image blurring.

[0028] The advantages of adopting the above-mentioned further solutions are that the single-step filtering algorithm reduces data processing steps and computational latency; the direct merging mode avoids excessive modification of energy signals by complex algorithms, preserves the original density difference characteristics, eliminates image blurring at the algorithm level, and reduces the hardware computing load of the device, thereby reducing research and development and maintenance costs.

[0029] Furthermore, the annular lead chopper wheel has a thickness of 10-20 mm, an inner diameter of 80-150 mm, an outer diameter of 120-200 mm, and a 45-degree chamfered edge at the beam exit to reduce X-ray scattering.

[0030] The advantages of adopting the above-mentioned further solutions are that the optimized size design takes into account both structural rigidity and installation space compatibility; the 45-degree chamfer effectively reduces the diffuse reflection of X-rays at the edge of the aperture, reduces the interference of scattered light on the detector, increases the energy ratio of the main beam, and further optimizes the imaging contrast.

[0031] Furthermore, the distance between the X-ray source and the inner end face of the beam exit aperture is 5-10 mm, and the emitted X-rays are collimated by the beam exit aperture and then directed as a parallel beam toward the object being scanned.

[0032] The advantages of adopting the above-mentioned further scheme are that the short-spacing design shortens the X-ray collimation path, reduces beam divergence loss, and ensures the parallelism of the outgoing beam; when the parallel beam irradiates the object under inspection, the energy distribution is uniform, avoiding density recognition errors caused by uneven local irradiation intensity, and improving the overall consistency of imaging.

[0033] Furthermore, the n value of the array imaging can be adjusted within the range of 1000-5000 according to the size of the scanned object to ensure complete coverage of density information.

[0034] The beneficial effect of adopting the above-mentioned further solution is that the flexible adjustment of the n value can adapt to different size requirements from small precision parts to large industrial components, avoid data redundancy of small objects or data loss of large objects caused by fixed array size, and ensure that the density information of each type of inspected object can be presented completely and efficiently.

[0035] Furthermore, the chopper wheel adopts a split structure, and the output module is detachably connected by bolts, which facilitates the quick replacement of modules with different apertures according to testing requirements.

[0036] The beneficial effects of adopting the above-mentioned further solutions are that they improve equipment adaptability and reduce adjustment costs for different precision requirements.

[0037] Furthermore, the energy acquisition threshold of the detector at the pixel can be preset by computer, enabling accurate identification of substances within a specific density range.

[0038] The beneficial effects of adopting the above-mentioned further solutions are that they expand the application scenarios and improve the targeting and accuracy of substance identification. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0040] 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.

[0041] In the embodiments, by Figure 1 A high-speed chopper wheel scanning imaging method is presented, and the specific implementation process is as follows: Hardware assembly and calibration: (1) Assemble the chopper assembly: Select lead material with a density equivalent to that of steel plate to process the ring chopper. The ring body thickness is 15 mm, the inner diameter is 100 mm, and the outer diameter is 160 mm. Four equally spaced beam outlets are processed in the circumferential direction at a central angle of 90°. The diameter of the beam outlet is 0.5 mm. Ensure that the spacing between adjacent beam outlets is uniform and the spacing error is ≤ ±0.1 mm. (2) Install the X-ray source: Fix the X-ray source at the center of the chopper ring, adjust the position of the source to ensure that the emitting end is collinear with the central axis of the beam aperture, and the distance between the source and the inner end face of the beam aperture is 7 mm; (3) Install the detector: Fix the X-ray detector with a pixel count of 1024×1024 to the outside of the chopper wheel, so that the receiving surface of the detector is perpendicular to the beam exit direction and the distance between the receiving surface and the outside of the chopper wheel is 35cm. (4) Install positioning structure: Fix the photoelectric switch near the chopper wheel, calibrate the detection probe to the edge of the beam outlet, ensure that the beam outlet position data can be accurately captured, and complete the signal connection with the computer; (5) Adjusting the transport of the object to be inspected: Place the object to be scanned on the dynamic transport mechanism near the detector, adjust the transport speed, and ensure that the object passes through the detection area at a constant speed; (6) Overall calibration: Start the equipment under no-load operation to calibrate the detection accuracy of the photoelectric switch, the speed stability of the chopper wheel and the signal transmission quality of the detector, and ensure that all components are operating normally.

[0042] Parameter settings: (1) Set the chopper speed to 800 revolutions per minute. Based on the characteristic of four equally spaced beam outlets, the interval time between adjacent beam outlets is calculated to be t=0.015 seconds. (2) Set the number of energy lines collected by the detector during the interval time t to 120 lines to ensure sufficient energy collection; (3) Set the array n value after data merging to 1500 to ensure imaging density and integrity.

[0043] Scanning and imaging operations: (1) Start the conveyor mechanism to move the object to be scanned into the detection area; (2) The chopper wheel rotates at high speed, and the photoelectric switch detects the position of the beam opening in real time and transmits it to the computer. The computer calculates the interval time t in real time. (3) During each time interval t, the detector integrates the X-ray energy reflected by the object being inspected through each pix acquisition point and transmits it to the computer through the energy acquisition module; (4) The filtering module removes environmental interference signals from the energy data, and the data merging module merges the processed data into vertical line energy data, forming an array through 1500 merged data; (5) The density restoration module analyzes the energy fluctuation differences of each pixel of the detector, restores the internal density distribution of the object under test, outputs the imaging results and stores them.

[0044] In this embodiment, the imaging resolution reaches 0.2 mm, the density detection error is 3.2%, and the scanning speed is 45 lines per second. Compared with existing backscatter imaging technology, it achieves significant improvements in energy harvesting efficiency, imaging accuracy, and scanning speed. It effectively solves the problems of weak X-ray energy, low resolution, blurry images, complex algorithms, and slow scanning in existing technologies, and fully meets the actual needs of density detection inside objects. Working principle: The core working principle of this invention is to overcome the core defects of existing technologies through regular structural design and precise timing control. First, the chopper wheel adopts a regular design with four equidistant beam exits, unlike the irregular beam exit structures in existing technologies. This ensures that the chopper wheel can stably collect 4-line flying point X-ray energy data in one rotation, and the faster the rotation speed, the higher the scanning imaging efficiency. At the same time, the lead ring structure acts as a collimator, which can effectively constrain the X-ray propagation direction and reduce energy scattering. Combined with the built-in X-ray source design, it shortens the X-ray transmission path and solves the problem of weak X-ray energy in existing technologies.

[0045] Secondly, the photoelectric switch, acting as a beam exit position identification device, captures the beam exit position data in real time during rotation. The computer accurately calculates the interval time t based on the rotational speed and equidistant characteristics. This time serves as the synchronization reference for the detector's energy acquisition, ensuring a perfect match between the acquisition action and the X-ray emission sequence. Within the interval time t, the detector employs an integral acquisition mode, accumulating multi-line energy data to further enhance the weak signal strength and improve acquisition efficiency.

[0046] Subsequently, the computer filters and denoises the acquired energy data, eliminating interference signals and merging them into a vertically aligned energy data line. This design significantly simplifies traditional complex imaging algorithms, reduces data processing difficulty, and avoids image blurring. Finally, utilizing the correlation between X-ray energy and material density—that is, the higher the internal density of the object being examined, the stronger the reflected X-ray energy, and the greater the energy fluctuation difference between adjacent pixels on the detector—a dedicated algorithm analyzes this energy difference distribution, inversely derives and reconstructs the internal density information of the object being examined, and ultimately outputs clear and accurate imaging results, significantly improving material identification efficiency.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-speed chopper wheel scanning imaging method, comprising core structure configuration and imaging operation steps, as detailed below: Core structural configuration: (a) A ring-shaped chopper is made of lead material with a density equivalent to or higher than that of steel plate. The chopper has four equidistant beam outlets evenly distributed in the circumferential direction. The beam outlets penetrate the inner and outer sides of the chopper and are used for collimating X-rays. (b) The X-ray source is fixedly built into the annular central region of the chopper wheel, with the emitting end facing the beam outlet; (c) The detector is fixedly placed outside the chopper wheel, and the receiving surface of the detector corresponds to the emission direction of the beam outlet, so as to receive the X-ray energy reflected by the scanned object; (d) A photoelectric switch is fixedly installed near the chopper wheel to detect the position data of the beam outlet during rotation; (e) The object being scanned is dynamically placed in the detection area near the detector; Imaging operation steps: S1. Drive the chopper wheel to rotate at high speed, collect the beam position data through the photoelectric switch and transmit it to the computer to calculate the interval time t between two adjacent beam outlets; S2. Within the interval time t, the detector integrates and collects the flying point X-ray energy reflected by the scanned object, and the chopper completes the 4-line flying point X-ray energy collection in one rotation. S3. The computer filters the energy data within the interval time t and merges it into vertical line energy data. The merged energy data is then used to form an array of n (n≥1000) merged energy data. S4. By utilizing the energy fluctuation differences between adjacent acquisition points of the detector, the internal density information of the scanned object is restored through computer image processing, thereby improving the efficiency of material identification.

2. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The spacing error of the four beam exits is ≤ ±0.1 mm, and the beam aperture is 0.1-1 mm. The smaller the aperture, the higher the imaging resolution. Among them, the 0.1-0.3 mm aperture is suitable for high-resolution detection, and the 0.4-1 mm aperture is suitable for conventional detection.

3. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The chopper wheel rotates at a speed of 500-2000 revolutions per minute, and the rotation speed is positively correlated with the scanning imaging speed. The maximum scanning speed is ≥40 lines per second, which is a significant improvement over existing technologies.

4. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The photoelectric switch has a detection accuracy of 0.001 mm, a signal transmission delay time of ≤5 ms, and an interval time t calculation accuracy of ≤±0.002 seconds.

5. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: Within the specified time interval t, the detector integrates and acquires ≥100 X-ray energy lines, improving energy acquisition efficiency by 30% compared to existing technologies.

6. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The detector is an X-ray dedicated array structure with a pixel count of no less than 1024×1024 and an energy spectrum imaging resolution of 0.1-0.3 mm.

7. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The data filtering process employs a simplified algorithm, replacing the complex algorithms of existing technologies with a single-step filtering and denoising method combined with direct merging of energy data, thus avoiding image blurring.

8. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The annular lead chopper wheel has a thickness of 10-20 mm, an inner diameter of 80-150 mm, and an outer diameter of 120-200 mm. The edge of the beam exit aperture has a 45-degree chamfer to reduce X-ray scattering.

9. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The distance between the X-ray source and the inner end face of the beam exit is 5-10 mm. The emitted X-rays are collimated by the beam exit and then directed as a parallel beam toward the object being scanned.

10. The high-speed chopper wheel scanning imaging method according to claim 1, characterized in that: The n value of the array imaging can be adjusted within the range of 1000-5000 according to the size of the scanned object to ensure complete coverage of density information.

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