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EP-3239699-B1 - BACKSCATTER-IMAGING BASED INSPECTING SYSTEM AND METHOD

EP3239699B1EP 3239699 B1EP3239699 B1EP 3239699B1EP-3239699-B1

Inventors

  • LI, YUANJING
  • Li, Mingliang
  • LI, JIANMIN
  • Chen, Minyan

Dates

Publication Date
20260513
Application Date
20170329

Claims (10)

  1. A backscatter-imaging based inspecting system, comprising: a ray source (110, 210, 310, 420, 610) for emitting rays to an inspected object; a multi-energy backscatter detector (120) for receiving rays scattered by the inspected object and outputting ray signals, wherein the multi-energy backscatter detector (120) is a dual-energy backscatter detector (220), the dual-energy backscatter detector (220) comprises: a low energy backscatter detector (221, 320); and a high energy backscatter detector (222, 330), wherein the low energy backscatter detector (221, 320) and the high energy backscatter detector (222, 330) comprise a plurality of backscatter detecting modules (620, 630) in different positions and directions, and a processing device (130, 230, 350, 430, 640, 830) connected to the ray source (110, 210, 310, 420, 610) and the multi-energy backscatter detector (120) respectively, for receiving the ray signals from the multi-energy backscatter detector, and processing the ray signals to obtain an image of the inspected object, and whereby the backscatter-imaging based inspecting system is characterised by that each of the backscatter detecting modules (620, 630) is ring-shaped, and the plurality of backscatter detecting modules (620, 630) are disposed coaxially.
  2. The system according to Claim 1, characterized in that , the high energy backscatter detector (222, 330) comprises a plurality of high energy backscatter detecting units arranged in a predetermined interval.
  3. The system according to Claim 1, characterized in that , the ray source (110, 210, 310, 420, 610) is a multi-energy ray source (810), for emitting rays having different energies.
  4. The system according to Claim 3, characterized in that , the ray source (110, 210, 310, 420, 610) is a dual-energy ray source (810), for emitting high energy rays and low energy rays.
  5. The system according to any of Claims 1, characterized in that , the multi-energy backscatter detector (120) is a flat panel detector, and/or the multi-energy backscatter detector (120) is made of a scintillator material.
  6. The system according to Claim 5, characterized in that , the scintillator material is an organic scintillation crystal polystyrene.
  7. A backscatter-imaging based inspecting method, comprising: emitting, by a ray source, rays to an inspected object; splitting, by a low energy backscatter detector, and a high energy backscatter detector, scattered rays by the inspected object into low energy ray signals and high energy ray signals from scattered rays by the inspected object, wherein the low energy backscatter detector and the high energy backscatter detector comprise a plurality of backscatter detecting modules in different positions and directions, and processing, by a processing device, the low energy ray signals and the high energy ray signals received from the dual-energy backscatter detector to obtain an image of the inspected object, whereby the backscatter-imaging based inspecting method is characterised by that each of the backscatter detecting modules is ring-shaped, and the plurality of backscatter detecting modules are disposed coaxially.
  8. The method according to Claim 7, characterized in further comprising: comparing, by the processing device, a parameter of every received high energy ray signals and low energy ray signals with corresponding parameter of high energy ray signals and low energy ray signals in a known material data table, to determine a material of the inspected object, wherein the known material data table contains mapping relations between every known material and a parameter of high and low energy ray signals, wherein the high and low energy ray signals are scattered by the known material and received by the dual -energy backscatter detector.
  9. The method according to Claim 7, characterized in further comprising: Obtaining, by the processing device, multiple beams of the high energy ray signals and multiple beams of the low energy ray signals in different directions, from the dual -energy backscatter detector; and generating an image of the inspected object based on the multiple beams of the high energy ray signals and the multiple beams of the low energy ray signals in the different directions.
  10. The method according to Claim 9, characterized in further comprising: comparing, by the processing device, parameters of every received multiple beams of the high energy ray signals and multiple beams of the low energy ray signals in different directions with corresponding parameters of multiple beams of high and low energy ray signals in different directions in the known material data table, to determine a material of the inspected object, wherein the known material data table contains mapping relations between every known material and parameters of multiple beams of high and low energy ray signals in different directions, wherein the multiple beams of high and low energy ray signals in different directions are scattered by the known material and received by the dual -energy backscatter detector.

Description

TECHNICAL FIELD The present disclosure relates to the technical field of backscatter, and particularly relates to a backscatter-imaging based inspecting system and method. BACKGROUND In recent years, with great importance attached to public security in the international community, X-ray backscatter technologies also gained remarkable advances. X-ray transmission technologies can make the inspected object perspective, but have a poor resolution to a material having a low atomic number, and cannot well present a small amount of light and thin organic matters such as drugs, thin explosives and etc. particularly. Although X-ray backscatter technologies have penetrating capabilities inferior to transmitting capabilities, they are very sensitive to substances having a low atomic number, and can highlight dangerous goods such as explosives and drugs. Besides, the backscatter technologies are also used in green channels on expressways to intelligently inspect agricultural products, which avoids time and energy wasting of hand inspection. However, the current backscatter technologies have very limited material resolutions, and particularly many non-contraband organic matters differ from contraband goods such as drugs and explosives very slightly in the atomic number, so it is hard for the existing backscatter technologies to distinguish them from one another, which tremendously limits the application of the technologies. In order to facilitate the development of the backscatter technologies, and improve distinguish ability on low atomic number materials, it is an urgent requirement to improve the distinguish ability by the backscatter technologies. US 2012/201356 A1 relates to systems and methods for classifying materials as to their effective atomic numbers based on the detection of penetrating radiation scattered therefrom. The backscatter-imaging based inspecting system comprises a ray source for emitting rays to an inspected object, a multi-energy backscatter detector for receiving rays scattered by the inspected object and outputting ray signals, and a processing device connected to the ray source and the multi-energy backscatter detector respectively, for receiving the ray signals from the multi-energy backscatter detector, and processing the ray signals to obtain an image of the inspected object. Further, US 2012/201356 A1 discloses a backscatter-imaging based inspecting method, comprising: Emitting rays to an inspected object from a ray source; obtaining low energy ray signals which are scattered by the inspected object and received by a low energy backscatter detector, and high energy ray signals which are scattered by the inspected object and received by a high energy backscatter detector; and generating an image of the inspected object based on the ray signals having different energies. With higher and higher requirements on intelligence of inspecting systems, a system without a distinguish ability of material is very limited in its intelligent discrimination capabilities and thus has very high false alarm rate and missing report rate. Only those backscatter systems which can distinguish from different materials can be satisfied to the requirements on intelligence. SUMMARY A technical problem to be solved in the disclosure is to provide a backscatter-imaging based inspecting system and method, capable of improving the material distinguish ability of an inspecting system. According to an aspect of the disclosure, a backscatter-imaging based inspecting system according to claim 1 is provided. Further, the high energy backscatter detector comprises a plurality of high energy backscatter detecting units arranged in a predetermined interval. According to the claimed invention, the multi-energy backscatter detector comprises a plurality of backscatter detecting modules in different positions and directions, for receiving rays in various directions, scattered by the inspected object, and outputting the ray signals, respectively. According to the claimed invention, each of the backscatter detecting modules is ring-shaped, and the plurality of backscatter detecting modules are disposed coaxially, or the plurality of backscatter detecting modules are arranged in a rectangular array. Further, the ray source is a multi-energy ray source, for emitting rays having different energies. Further, the ray source is a dual-energy ray source, for emitting high energy rays and low energy rays. Further, the multi-energy backscatter detector is a flat panel detector, and/or the multi-energy backscatter detector is made of a scintillator material. Further, the scintillator material is an organic scintillation crystal polystyrene. According to another aspect of the disclosure, a backscatter-imaging-based inspecting system is further provided, comprising: a multi-energy ray source for generating rays having different energies, and emitting rays to an inspected object; a backscatter detector for receiving rays scattered by the inspe