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CN-122016889-A - High-speed chopper wheel scanning imaging method

CN122016889ACN 122016889 ACN122016889 ACN 122016889ACN-122016889-A

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 concretely comprises the following steps of (a) manufacturing an annular chopper wheel by adopting lead materials with the density equal to or higher than that of a steel plate, wherein the number of equidistant beam outlets uniformly distributed in the circumferential direction of the chopper wheel is four, the beam outlets penetrate through the inner side and the outer side of the chopper wheel and are used for collimating X rays, (b) an X-ray source is fixedly arranged in the annular central area of the chopper wheel, a transmitting end faces towards the beam outlet, and (c) a detector is fixedly arranged outside the chopper wheel, and a receiving surface of the detector corresponds to the emergent direction of the beam outlet and is used for receiving X-ray energy reflected by a scanned object. According to the high-speed chopper wheel scanning imaging method, synchronous improvement of energy collection efficiency, imaging precision and scanning speed is achieved by optimizing chopper wheel structural design and imaging flow, an imaging algorithm is simplified, and a core pain point in the prior art is solved.

Inventors

  • LI LINGYUN

Assignees

  • 武汉艾崴科技有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The high-speed chopper wheel scanning imaging method comprises the following steps of core structure configuration and imaging operation: and (3) core structure configuration: (a) The method comprises the steps that an annular chopping wheel is made of lead materials with the density equal to or higher than that of a steel plate, four equidistant beam outlets are uniformly distributed in the circumferential direction of the chopping wheel, and the beam outlets penetrate through the inner side and the outer side of the chopping wheel and are used for collimating X-rays; (b) The X-ray source is fixedly arranged in the annular central area of the chopper wheel, and the emitting end faces the beam outlet; (c) The detector is fixedly arranged outside the chopping wheel, the receiving surface of the detector corresponds to the emergent direction of the beam outlet and is used for receiving the X-ray energy reflected by the scanned object; (d) The photoelectric switch is fixedly arranged near the chopping wheel and used for detecting position data of the beam outlet in the rotating process; (e) The scanned object is dynamically placed in a detection area near the detector; imaging operation steps: s1, driving a chopper wheel to rotate at a high speed, acquiring position data of beam outlets through a photoelectric switch, transmitting the position data to a computer, and calculating interval time t of two adjacent beam outlets; s2, in interval time t, integrating and collecting flying spot X-ray energy reflected by a scanned object by a detector, and completing 4-line flying spot X-ray energy collection by rotating a chopper wheel for one circle; s3, the computer carries out filtering treatment on the energy data in the interval time t, the energy data are combined into vertical line energy data, and an array is formed by n (n is more than or equal to 1000) combined energy data; S4, reducing the internal density information of the scanned object by computer image processing by utilizing the energy fluctuation difference of the adjacent acquisition points of the detector, and improving the material identification efficiency.
  2. 2. The method of claim 1, wherein the pitch error of the 4 beam outlets is less than or equal to + -0.1 mm, the aperture of the beam outlet is 0.1-1 mm, the smaller the aperture, the higher the imaging resolution, wherein the aperture of 0.1-0.3 mm is suitable for high resolution detection, and the aperture of 0.4-1 mm is suitable for conventional detection.
  3. 3. The high-speed chopper wheel scanning imaging method of claim 1, wherein the chopper wheel rotating speed is 500-2000 revolutions per minute, the rotating speed is positively correlated with the scanning imaging speed, and the highest scanning speed is more than or equal to 40 lines per second, which is obviously improved compared with the prior art.
  4. 4. The method for scanning and imaging of a high-speed chopper wheel as claimed in claim 1, wherein the detection precision of the photoelectric switch is 0.001 mm, the signal transmission delay time is less than or equal to 5ms, and the calculation precision of the interval time t is less than or equal to +/-0.002 seconds.
  5. 5. The high-speed chopper wheel scanning imaging method of claim 1, wherein the number of X-ray energy lines collected by the detector in an integral way is more than or equal to 100 lines in the interval time t, and the energy collection efficiency is improved by 30% compared with the prior art.
  6. 6. The method of claim 1, wherein the detector is of an X-ray special array structure, the pix number is not less than 1024X 1024, and the spectral imaging resolution is 0.1-0.3 mm.
  7. 7. The method of claim 1, wherein the data filtering process uses a simplified algorithm to avoid image blurring by replacing the complex algorithm of the prior art with a single-step filtering denoising and direct combination of energy data.
  8. 8. The method of claim 1, wherein the thickness of the ring-shaped lead chopper wheel is 10-20 mm, the inner diameter is 80-150 mm, the outer diameter is 120-200 mm, and the beam outlet edge is provided with a forty-five degree chamfer structure to reduce X-ray scattering.
  9. 9. The method of claim 1, wherein the distance between the X-ray source and the inner side end surface of the beam outlet is 5-10 mm, and the X-ray is collimated by the beam outlet and then emitted to the scanned object in parallel.
  10. 10. The method of claim 1, wherein the n-value of the array is adjustable within a range of 1000-5000 based on the size of the object being scanned to ensure complete coverage of the density information.

Description

High-speed chopper wheel scanning imaging method Technical Field The invention relates to the technical field of radiation imaging, in particular to a high-speed chopper wheel scanning imaging method which is applied to detection of information such as material density and the like in a scanned object, is suitable for radiation imaging related scenes such as industrial detection, security screening and the like, and belongs to the technical field of nuclear radiation measurement of high-end equipment manufacturing industry. Background In the field of radiation imaging, material density detection in an object is a core application requirement, and currently, a back scattering imaging technology is mainly adopted in the industry, and the technology realizes imaging by receiving X-ray energy reflected based on Compton effect through a detector. The core principle is that the reflected signal after the interaction of X-ray and the substance in the object is utilized to reversely deduce the internal structure and density distribution of the object, and the method is applied to the related field to a certain extent by virtue of the advantages of non-contact detection. However, the existing back scattering imaging technology has a plurality of defects which are difficult to overcome, and the detection effect and efficiency are seriously affected. Firstly, the reflected X-ray energy is extremely weak, so that the signal acquisition efficiency of the detector is low, a complex algorithm is needed to carry out signal enhancement, the data processing difficulty is increased, interference noise is easy to introduce, secondly, the energy spectrum imaging resolution is low, the imaging is usually only up to less than or equal to 0.8 mm, the imaging is fuzzy, the fine structure and density difference in the object are difficult to accurately identify, furthermore, the imaging algorithm is complex, the equipment research and development and maintenance cost is further increased, the scanning speed is slow (less than or equal to 10 lines per second), and the batch detection requirement cannot be met. In addition, most of beam outlet holes of chopper wheels in the prior art are irregularly designed, so that energy is acquired unevenly, and the problems of image blurring and insufficient resolution are further aggravated. A high-speed chopper wheel scanning imaging method is proposed to solve the above-mentioned problems. Disclosure of Invention (One) solving the technical problems Aiming at the technical contradiction that the existing back scattering imaging technology has weak X-ray energy, low energy spectrum imaging resolution, image blurring, complex imaging algorithm, low scanning speed and uneven energy collection caused by irregular beam outlet holes of the existing chopping wheel, the invention provides a high-speed chopping wheel scanning imaging method which realizes synchronous promotion of energy collection efficiency, imaging precision and scanning speed by optimizing the structure design and imaging flow of the chopping wheel, simplifies the imaging algorithm and solves the core pain point of the prior art. (II) technical scheme The technical scheme for solving the technical problems is as follows: and (3) core structure configuration: (a) The chopper wheel structure is characterized in that four equidistant regular beam outlets are arranged on the annular body, the distance between adjacent beam outlets is uniform, the chopper wheel can stably collect 4-line flying spot X-ray energy data after rotating for one circle, the higher the rotation speed is, the higher the scanning imaging efficiency is, the size of the beam outlet can be adjusted according to the precision requirement, the smaller the aperture is, the higher the imaging resolution is, and the problem of nonuniform energy collection is structurally solved. (B) The light source and the detector are arranged, the X-ray source is fixedly arranged in the annular center of the chopper wheel, the X-ray transmission path is shortened, the energy loss is reduced, the detector is fixedly arranged outside the chopper wheel and corresponds to the emergent direction of the beam outlet accurately, and effective receiving of reflected X-ray energy is ensured. (C) The photoelectric switch is fixed near the chopper wheel and used as a beam outlet position recognition device to capture the position data of the beam outlet in the rotating process in real time, thereby providing a basis for the accurate calculation of the interval time t. (D) And placing the object to be detected, namely dynamically placing the object to be scanned near the detector, enabling the object to pass through the detection area along with the conveying mechanism at a constant speed, and adapting to batch detection scenes. Imaging operation steps: s1, time sequence calibration, namely when the chopper wheel rotates at a high speed, the photoelectric switch transmits the detected position data