Object detection method and system

Abstract

The embodiment of the present application provides an object detection method and system. The object detection method includes: obtaining the ray characteristic information of the gamma ray emitted by the object to be detected when irradiated by a neutron beam; obtaining the gamma ray energy spectrum and the nuclide spatial distribution map of the object to be detected based on the ray characteristic information of the gamma ray; and determining the detection result of the object to be detected according to the gamma ray energy spectrum and the nuclide spatial distribution map. According to the object detection method of the embodiment of the present application, the accuracy of the detection result can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of security inspection, and in particular, relates to an object detection method and system. Background Art

[0002] In security inspection business scenarios, it is necessary to detect whether the object to be inspected is a target type object, such as flammable and explosive items, drugs and other dangerous items.

[0003] In the prior art, a gamma-ray spectrometer is usually used to detect the gamma rays emitted after the atomic nuclei of the object to be detected react with the neutron beam to obtain a gamma-ray energy spectrum corresponding to the object to be detected. Whether the object to be detected is a target type object is determined based on the gamma-ray energy spectrum. However, since the gamma-ray energy spectra of many daily necessities, foods, tools, materials and other items are similar to those of target type objects, the method of determining whether the object to be detected is a target type object based on the gamma-ray energy spectrum of the object to be detected has the problem of low accuracy of the detection result. Summary of the invention

[0004] The embodiments of the present application provide an object detection method and system, which can improve the accuracy of detection results.

[0005] In a first aspect, an embodiment of the present application provides an object detection method, comprising:

[0006] Acquiring ray characteristic information of gamma rays emitted by the object to be detected when irradiated by a neutron beam;

[0007] Processing the characteristic information of gamma rays to obtain the gamma ray energy spectrum and nuclide spatial distribution map of the object to be detected;

[0008] Determine whether the object to be detected is a target type object based on the gamma ray energy spectrum and the nuclide spatial distribution map.

[0009] In some embodiments, obtaining ray characteristic information of gamma rays emitted by the object to be detected when irradiated by a neutron beam includes:

[0010] Performing a first detection and a second detection on each cross section of the object to be detected to obtain first ray characteristic information and second ray characteristic information of the gamma ray of the object to be detected, wherein an angle between the encoding plate when performing the first detection and the encoding plate when performing the second detection is less than or equal to ninety degrees;

[0011] The characteristic information of gamma rays is processed to obtain the nuclide spatial distribution map of the object to be detected, including:

[0012] The first ray characteristic information and the second ray characteristic information are decoded to obtain a nuclide spatial distribution diagram of the object to be detected.

[0013] In some embodiments, determining whether the object to be detected is a target type object according to the gamma ray energy spectrum and the nuclide spatial distribution map includes:

[0014] Selecting a first target characteristic nuclide on the gamma-ray energy spectrum;

[0015] Determining first distribution information of a first target characteristic nuclide on a nuclide spatial distribution map;

[0016] When the first distribution information represents that the first target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

[0017] In some embodiments, the nuclide spatial distribution map is a two-dimensional nuclide spatial distribution map;

[0018] Determine whether the object to be detected is a target type object based on the gamma ray energy spectrum and the nuclide spatial distribution map, including:

[0019] Selecting a first target characteristic hotspot on a two-dimensional nuclide spatial distribution map;

[0020] Determine the first characteristic nuclide composition corresponding to the first target characteristic hot spot on the gamma-ray energy spectrum;

[0021] Selecting a second target characteristic nuclide from the first characteristic nuclide composition;

[0022] Determine second distribution information of the second target characteristic nuclide in the first target characteristic hotspot;

[0023] When the second distribution information represents that the second target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

[0024] In some embodiments, the nuclide spatial distribution map is a three-dimensional nuclide spatial distribution map;

[0025] Determine whether the object to be detected is a target type object based on the gamma ray energy spectrum and the nuclide spatial distribution map, including:

[0026] Constructing a three-dimensional nuclide spatial distribution map of the object to be detected based on the two-dimensional nuclide spatial distribution map of each section of the object to be detected;

[0027] Selecting a second target characteristic hotspot on the three-dimensional nuclide spatial distribution map;

[0028] Determining the second characteristic nuclide composition corresponding to the second target characteristic hotspot on the gamma-ray energy spectrum corresponding to the second target characteristic hotspot;

[0029] Selecting a third target characteristic nuclide from the second characteristic nuclide composition;

[0030] Determine third distribution information of the third target characteristic nuclide in the second target characteristic hotspot;

[0031] When the third distribution information represents that the third target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

[0032] In some embodiments, before obtaining the ray characteristic information of the gamma ray emitted by the object to be detected when irradiated by the neutron beam, the method further includes:

[0033] The neutron beam is collimated to obtain a neutron beam of a preset shape, and the neutron beam of the preset shape is used to irradiate the object to be detected.

[0034] In some embodiments, before the neutron beam is collimated to obtain a neutron beam of a preset shape, the method further includes:

[0035] Moder the neutron beam to obtain a thermal neutron beam;

[0036] The neutron beam is collimated to obtain a neutron beam of a preset shape, including:

[0037] The thermal neutron beam is collimated to obtain a thermal neutron beam of a preset shape, and the thermal neutron beam of the preset shape is used to irradiate the object to be detected.

[0038] In a second aspect, an embodiment of the present application provides an object detection system, including a neutron ray source, a gamma camera, and a detection device:

[0039] A neutron ray source, used for generating a neutron beam, and the neutron beam is used for irradiating an object to be detected;

[0040] The gamma camera is used to obtain the ray characteristic information of the gamma rays emitted by the object to be detected when irradiated by the neutron beam; the ray characteristic information of the gamma rays is processed to obtain the gamma ray energy spectrum and the nuclide spatial distribution map of the object to be detected;

[0041] The detection device is used to determine whether the object to be detected is a target type object according to the gamma ray energy spectrum and the nuclide spatial distribution diagram.

[0042] In some embodiments, the gamma camera is a code plate gamma camera; the code plate gamma camera includes a detector array, a code plate, a code plate rotating device, and a decoding device;

[0043] Detector arrays for:

[0044] Performing first detection and second detection on the gamma rays penetrating the coding plate and emitted from each section of the object to be detected, to obtain first ray characteristic information and second ray characteristic information of the gamma rays of the object to be detected;

[0045] Code plate turning device for:

[0046] Control the angle between the encoding plate when performing the first detection and the encoding plate when performing the second detection to be less than or equal to ninety degrees;

[0047] Decoding means for:

[0048] The first ray characteristic information and the second ray characteristic information are decoded to obtain a nuclide spatial distribution diagram of the object to be detected.

[0049] In some embodiments, the object detection system further comprises a collimator;

[0050] The input end of the collimator is connected to the output end of the neutron ray source, and is used to collimate the neutron beam into a neutron beam of a preset shape, and output the neutron beam of the preset shape to irradiate the object to be inspected.

[0051] In some embodiments, the object detection system further includes a moderator;

[0052] The input end of the moderator is connected to the output end of the neutron ray source, and the output end of the moderator is connected to the input end of the collimator;

[0053] The moderator is used to slow down the neutron beam into a thermal neutron beam, and input the thermal neutron beam into the collimator;

[0054] The collimator is used to collimate the thermal neutron beam to obtain a thermal neutron beam of a preset shape.

[0055] The object detection method and system of the embodiment of the present application obtains the gamma ray energy spectrum and nuclide spatial distribution diagram of the object to be detected by processing the ray characteristic information of the gamma ray emitted by the object to be detected. In this way, based on the gamma ray energy spectrum and nuclide spatial distribution diagram, not only the content and proportion of the characteristic nuclide can be determined, but also the spatial distribution of the characteristic nuclide can be determined. In this way, on the basis of the content and proportion of the characteristic nuclide, combined with the spatial distribution of the characteristic nuclide, it is determined whether the characteristic nuclide originates from the object to be detected, that is, it is possible to determine whether the detected object is a target type object based on the content, proportion and source of the characteristic nuclide, thereby avoiding interference from equipment other than the object to be detected, thereby effectively improving the accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0057] Figure 1 is a structural diagram of an object detection system provided in an embodiment of the present application;

[0058] Figure 2 is a structural diagram of an object detection system provided in an embodiment of the present application;

[0059] Figure 3 is a flow chart of an object detection method provided in an embodiment of the present application;

[0060] Figure 4 It is a structural schematic diagram of a gamma-ray energy spectrum diagram and a nuclide spatial distribution diagram provided in an embodiment of the present application;

[0061] Figure 5 It is a structural schematic diagram of a gamma-ray energy spectrum diagram and a nuclide spatial distribution diagram provided in an embodiment of the present application;

[0062] Figure 6 It is a structural schematic diagram of a gamma-ray energy spectrum diagram and a nuclide spatial distribution diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0063] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0064] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0065] Based on the background technology, it can be known that at present, whether the object to be detected is a target type object, such as flammable and explosive items, drugs and other dangerous items, is usually detected based on the gamma ray energy spectrum of the object to be detected.

[0066] When neutrons react with the nuclei of the object to be tested, they emit gamma rays, i.e., γ rays. Through a γ-ray spectrometer, the γ-ray energy spectrum of the object to be tested can be detected. Based on the γ-ray energy spectrum, the nuclides contained in the object to be tested and the content and proportion of each nuclide can be determined, so as to determine whether the object to be tested is or contains illegal flammable and explosive items, drugs and other dangerous items.

[0067] For example, the nuclides of explosive items usually include carbon (Carbon, C), hydrogen (Hydrogen, H), nitrogen (Nitrogen, N), oxygen (Oxygen, O), and the content of N and O is high, while the content of H and C is low. Many drugs require the participation of chlorine (Chlorine, Cl) substances in the preparation process. Therefore, by detecting and analyzing the content and proportion of nuclides such as H, N, O, and Cl, it is possible to detect whether the object to be detected is or contains explosives, drugs and other dangerous items.

[0068] Therefore, at present, accelerator photoneutron technology can usually be used to detect whether there are inflammable and explosive items, drugs and other dangerous items hidden inside containers, vehicles, bags and other objects to be inspected. The object to be inspected usually passes through the neutron beam plane horizontally, and is scanned, excited and detected by the neutron beam section by section. The accelerator photoneutron source can be designed as a pulsed, fan-shaped photoneutron source. The fan-shaped neutron beam emitted by the neutron source can be irradiated laterally onto the object to be inspected, and excite the nuclei on the entire transverse section of the object to be inspected. Subsequently, the excited nuclei are de-excited and emit gamma rays. The gamma-ray spectrometer can be placed at a position of ninety degrees to the fan-shaped neutron beam plane, and work during the pulse interval of the neutron source to avoid the high-flux X-ray background interference of the accelerator photoneutron source.

[0069] However, since many daily necessities, foods, tools, materials and other items also contain relatively high levels of N, O, Cl and other elements, and their contents and proportions are similar to those of target type objects, and their gamma ray energy spectra are also similar to those of target type objects, only based on the gamma ray energy spectra to detect the object to be detected and determine whether it is a target type object, there will be false detection, resulting in low accuracy of the detection results.

[0070] At the same time, the inventors found that the gamma camera, i.e., the γ camera, can measure the energy and angle of the detected γ rays. Common γ cameras include three categories. Pinhole imaging type: composed of a pinhole plate and a two-dimensional position-sensitive γ detector, suitable for positioning measurement of low-energy and high-intensity ray sources; Compton γ camera type: composed of two groups of two-dimensional position-sensitive γ detectors at the front and back, suitable for positioning measurement of low-energy and low-intensity ray sources; Encoding plate imaging γ camera type: composed of a rotatable encoding plate at the front and a two-dimensional position-sensitive γ detector at the rear, suitable for positioning measurement of higher energy and higher intensity ray sources. After the neutron reacts with the nucleus of the object to be detected, the nucleus of the object to be detected is activated and emits γ rays during de-excitation decay. The γ camera can be used to detect the intensity and spatial distribution of γ rays.

[0071] Therefore, based on the above findings, in order to solve the problems existing in the prior art, the inventors provide an object detection method and system in the embodiments of the present application, which can process the ray characteristic information of the gamma rays emitted by the object to be detected to obtain the gamma ray energy spectrum and the nuclide spatial distribution diagram of the object to be detected. Based on the content and proportion of the characteristic nuclide, combined with the spatial distribution of the characteristic nuclide, it is determined whether the characteristic nuclide originates from the object to be detected, thereby effectively improving the accuracy of the detection result.

[0072] The object detection method provided in the embodiment of the present application may be executed by an object detection system, such as Figure 1 As shown, the object detection system 100 may include a neutron ray source 110 , a gamma camera 120 and a detection device 130 .

[0073] The neutron ray source 110 may be used to generate a neutron beam, and the neutron beam may be used to irradiate an object to be detected.

[0074] The gamma camera 120 may be used to obtain ray characteristic information of gamma rays emitted by the object to be detected when irradiated by a neutron beam.

[0075] Furthermore, it can be used to process the ray characteristic information of gamma rays to obtain the gamma ray energy spectrum and nuclide spatial distribution diagram of the object to be detected.

[0076] The detection device 130 can be used to determine whether the object to be detected is a target type object according to the gamma ray energy spectrum diagram and the nuclide spatial distribution diagram.

[0077] The object to be detected is any object that needs to be detected.

[0078] The ray characteristic information may include at least one of the energy, angle, time and position of the gamma ray.

[0079] The neutron ray source 110 may be at least one of an accelerator neutron source, an isotope neutron source, a reactor neutron source, and a scattered neutron source, and the neutron ray source 110 may be configured to be pulsed or non-pulsed.

[0080] The target type object is a possible object type of the object to be detected, such as flammable and explosive items, drugs, etc.

[0081] In some embodiments, the gamma camera 120 may be a code plate gamma camera, which may include a detector array, a code plate, a code plate rotating device, and a decoding device.

[0082] The detector array may be composed of a plurality of two-dimensional position-sensitive detectors.

[0083] Detector arrays can be used to:

[0084] The gamma rays penetrating the coding plate and emitted from each section of the object to be detected are subjected to first detection and second detection to obtain first ray characteristic information and second ray characteristic information of the gamma rays of the object to be detected.

[0085] The encoder plate rotating device can be used for:

[0086] The angle between the encoding plate when the first detection is performed and the encoding plate when the second detection is performed may be less than or equal to ninety degrees.

[0087] A decoding device can be used to:

[0088] The first ray characteristic information and the second ray characteristic information are decoded to obtain a nuclide spatial distribution diagram of the object to be detected.

[0089] It is understandable that one or more gamma cameras may be provided in the object detection system, and the embodiments of the present application do not limit this.

[0090] In some embodiments, the object detection system 100 may further include a collimator, an input end of which may be connected to an output end of the neutron ray source 110 .

[0091] The collimator can be used to collimate the neutron beam into a neutron beam of a preset shape, and output the neutron beam of the preset shape to irradiate the object to be inspected. The preset shape can be a fan beam, a spot beam, a cone beam, etc.

[0092] In some embodiments, the object detection system 100 may further include a moderator, an input end of the moderator may be connected to an output end of the neutron ray source 110 , and an output end of the moderator may be connected to an input end of the collimator.

[0093] The moderator can be used to moderate the neutron beam into a thermal neutron beam, and the thermal neutron beam can be input into the collimator.

[0094] At this time, the collimator can be used to collimate the thermal neutron beam to obtain a thermal neutron beam of a preset shape, and output the thermal neutron beam of the preset shape to irradiate the object to be inspected.

[0095] For details, see Figure 2 , Figure 2 A schematic structural diagram of an object detection device provided in an embodiment of the present application is shown. Figure 2 1 represents the object to be detected, 2 represents the thermal neutron beam, 3 represents the carrying device, 4 represents the gamma ray, 5 represents the encoding plate rotating device, 6 represents the encoding plate, 7 represents the detector array, 8 represents the shielding body, 9 represents the collimator, 10 represents the moderator, 11 represents the photoneutron conversion target, and 12 represents the electron accelerator.

[0096] The carrying device 3 may be configured as a transmission device or a tray, that is, when the object to be detected is irradiated with a neutron beam, the object to be detected may be in a stationary state or in a moving state.

[0097] The neutron ray source 110 may be composed of a photoneutron conversion target 11 and an electron accelerator 12, that is, the neutron ray source may be an accelerator photoneutron source. The accelerator photoneutron source is safe and easy to install, and is the most suitable neutron ray source for application in the security inspection field.

[0098] In other embodiments, the shielding body 8 may not be provided.

[0099] like Figure 2 As shown, the electron accelerator 12 can accelerate electrons and emit X-rays, and the X-rays are converted into a neutron beam after passing through the photoneutron conversion target 11. It is understandable that the neutron beam may also contain X-rays. After the photoneutron conversion target 11 of the neutron ray source 110 converts the X-rays into a neutron beam, the neutron beam can be emitted to the moderator 10, and the moderator 10 can slow down the neutron beam into a thermal neutron beam, and emit the thermal neutron beam to the collimator 9. The collimator 9 can collimate the thermal neutron beam to obtain a thermal neutron beam 2 of a preset shape, such as a fan-shaped thermal neutron beam, and can emit a thermal neutron beam 2 of a preset shape to irradiate the object 1 to be detected.

[0100] The object to be detected 1 can be placed on the carrying device 3. When the object to be detected 1 is irradiated by the thermal neutron beam 2 of a preset shape, the atomic nuclei of the object to be detected 1 will undergo a nuclear reaction with the thermal neutron beam 2 of the preset shape, and the nuclides of the object to be detected 1 will emit gamma rays 4 after de-excitation.

[0101] The working time of the gamma camera 120 is associated with the position of the neutron ray source 110 and the object to be detected 1 on the conveying device. That is, when the neutron ray source 110 pulses out, the gamma camera does not work; when the neutron ray source 110 pulses out, the gamma camera works.

[0102] The gamma camera 120 can use the coding plate 6 and the detector array 7 to perform a first detection on each section of the object to be detected 1 to obtain the first ray characteristic information of the gamma ray of the object to be detected 1. Then, the coding plate rotating device 5 is rotated ninety degrees, the carrying device 3 is reversely driven, and the coding plate 6 and the detector array 7 are used again to perform a second detection on each section of the object to be detected 1 to obtain the second ray characteristic information of the gamma ray of the object to be detected 1. The decoding device is used to decode the first ray characteristic information and the second ray characteristic information of the same section of the object to be detected to obtain the nuclide spatial distribution map of the object to be detected in the section, so that the detection device 130 can determine whether the object to be detected 1 is a target type object according to the gamma ray energy spectrum and the nuclide spatial distribution map.

[0103] The object detection system can execute the embodiments of the present application Figure 3 The object detection method shown in , its specific principles and effects can be seen in Figure 3 For the sake of brevity, the detailed description is not given here.

[0104] The object detection method provided in the embodiment of the present application is introduced below. Figure 3 , Figure 3 FIG. 1 is a flow chart of an object detection method provided in an embodiment of the present application. Figure 3 As shown, the method may include the following steps:

[0105] S310, obtaining ray characteristic information of gamma rays emitted by the object to be detected when irradiated by a neutron beam.

[0106] In the embodiment of the present application, when the object to be detected is detected, the object to be detected can be irradiated with a neutron beam, so that the atomic nuclei of the object to be detected react with the neutron beam under the irradiation of the neutron beam and emit gamma rays. Then, the ray characteristic information of the gamma rays emitted by the object to be detected when irradiated by the neutron beam can be obtained. The ray characteristic information may include at least one of the information such as the energy, angle, time and position of the gamma rays, or may also include the position of the object to be detected on the neutron beam plane.

[0107] S320, processing the ray characteristic information of the gamma ray to obtain a gamma ray energy spectrum diagram and a nuclide spatial distribution diagram of the object to be detected.

[0108] In the embodiment of the present application, after obtaining the ray characteristic information of the gamma ray, the ray characteristic information of the gamma ray can be processed to obtain the gamma ray energy spectrum and the nuclide spatial distribution map of the object to be detected. The nuclide spatial distribution map can be a two-dimensional nuclide spatial distribution map of the nuclide of the object to be detected on a certain section. Alternatively, the nuclide spatial distribution map can also be a distribution map of the nuclides contained in the object to be detected in a three-dimensional space, that is, a three-dimensional nuclide spatial distribution map.

[0109] S330, determining whether the object to be detected is a target type object based on the gamma ray energy spectrum and the nuclide spatial distribution diagram.

[0110] In the embodiment of the present application, after obtaining the gamma-ray energy spectrum of the object to be detected, it can be determined whether the object to be detected is a target type object according to the gamma-ray energy spectrum and the nuclide spatial distribution map. For example, it can be determined whether the gamma-ray energy spectrum of the object to be detected matches the reference gamma-ray energy spectrum of the target type object according to the gamma-ray energy spectrum of the object to be detected and the reference gamma-ray energy spectrum of the target type object; and it can be determined whether the characteristic nuclide comes from the object to be detected, or comes from other surrounding equipment and tools, or is diffused in the space according to the nuclide spatial distribution map of the gamma rays of the object to be detected.

[0111] The characteristic nuclide is a nuclide used to characterize the target type object. For example, when the target type object is an explosive item, the characteristic nuclide may be C, H, N, O, or the like.

[0112] If the gamma ray energy spectrum of the object to be detected matches the reference gamma ray energy spectrum of the target type object, and the characteristic nuclides in the nuclide spatial distribution diagram of the gamma rays of the object to be detected originate from the object to be detected, it can be determined that the object to be detected is a target type object.

[0113] The object detection method and system of the embodiment of the present application obtains the gamma ray energy spectrum and nuclide spatial distribution diagram of the object to be detected by processing the ray characteristic information of the gamma ray emitted by the object to be detected. In this way, based on the gamma ray energy spectrum and nuclide spatial distribution diagram, not only the content and proportion of the characteristic nuclide can be determined, but also the spatial distribution of the characteristic nuclide can be determined. In this way, on the basis of the content and proportion of the characteristic nuclide, combined with the spatial distribution of the characteristic nuclide, it is determined whether the characteristic nuclide originates from the object to be detected, that is, it is possible to determine whether the detected object is a target type object based on the content, proportion and source of the characteristic nuclide, thereby avoiding interference from equipment other than the object to be detected, thereby effectively improving the accuracy of the detection results.

[0114] In some embodiments, the gamma rays emitted by the object to be detected when irradiated by the neutron beam may be first detected and then detected to obtain a nuclide spatial distribution map. Accordingly, the specific implementation of the above step S310 may be as follows:

[0115] A first detection and a second detection are performed on each cross section of the object to be detected to obtain first ray characteristic information and second ray characteristic information of the gamma ray of the object to be detected.

[0116] Accordingly, the specific implementation method of obtaining the nuclide spatial distribution map of the object to be detected in the above step S320 can be as follows:

[0117] The first ray characteristic information and the second ray characteristic information are decoded to obtain a nuclide spatial distribution diagram of the object to be detected.

[0118] The first detection may be the first effective detection of the cross section of the object to be detected. An effective detection is a successful detection of the first ray characteristic information. Considering that detection failure may occur when detecting ray characteristic information, the first detection may be one detection or multiple detections.

[0119] The first ray characteristic information is ray characteristic information of the gamma ray of the object to be detected obtained by performing the first detection.

[0120] Similarly, the second detection may be a second effective detection of the cross section of the object to be detected, and the angle between the encoding plate during the second detection and the encoding plate during the first detection is less than or equal to ninety degrees, preferably ninety degrees.

[0121] Specifically, when obtaining the ray characteristic information of the gamma ray of the object to be detected, a first detection can be performed on a section of the object to be detected to obtain the first ray characteristic information of the gamma ray of the object to be detected. Then, the encoding plate is rotated by a preset angle or an angle whose difference from the preset angle is less than a preset threshold, and a second detection is performed on the section of the object to be detected to obtain the second ray characteristic information of the gamma ray of the object to be detected. After that, the aforementioned first ray characteristic information and the second ray characteristic information can be decoded and imaged to obtain the nuclide space distribution map corresponding to the section of the object to be detected. The nuclide space distribution map corresponding to each section is a two-dimensional nuclide space distribution map. The two-dimensional nuclide space distribution maps of multiple sections can be spliced ​​together to obtain a three-dimensional nuclide space distribution map of the object to be detected.

[0122] In this way, by obtaining the second ray characteristic information and the first ray characteristic information through two detections at a certain angle to each other, the coordinates of each collected nuclide on the two-dimensional plane can be obtained, and the two-dimensional nuclide spatial distribution map and the three-dimensional nuclide spatial distribution map of the object to be detected can be obtained through decoding imaging, thereby providing more accurate data basis for the detection of the object to be detected.

[0123] In some embodiments, whether the object to be detected is a target type object can be determined in a manner from a gamma ray energy spectrum to a nuclide spatial distribution diagram. Accordingly, the specific implementation of the above step S330 can be as follows:

[0124] Selecting a first target characteristic nuclide on the gamma-ray energy spectrum;

[0125] Determining first distribution information of a first target characteristic nuclide on a nuclide spatial distribution map;

[0126] When the first distribution information represents that the first target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

[0127] Among them, the first target characteristic nuclide is a characteristic nuclide selected on the gamma-ray energy spectrum that is greater than or equal to the minimum value of the content and / or proportion of the characteristic nuclide of the target type object. The number of the first target characteristic nuclides can be one or more. For example, if the target type object is an explosive item, its characteristic nuclides can be C, H, N, O, etc. Assuming that the characteristic nuclides of the object to be detected include C and H, and the content of the characteristic nuclides C and H of the target type object is 8% and 10% respectively, if the content of C and H in the characteristic nuclides of the object to be detected is higher than 8% and 10%, then C and H can be selected as the first target characteristic nuclides.

[0128] The first distribution information is the distribution information of the first target characteristic nuclide on the nuclide space distribution map, such as the source of the first target characteristic nuclide.

[0129] Specifically, when determining whether the object to be detected is a target type object, a first target characteristic nuclide may be selected on the gamma ray energy spectrum. The spatial distribution information of the first target characteristic nuclide, i.e., the first distribution information, is determined on the nuclide spatial distribution map. Figure 4 , Figure 4 Taking the first target characteristic nuclides as Cl, H, Fe (iron), and N as an example, a schematic diagram of first distribution information of the first target characteristic nuclides on the nuclide space distribution map is shown.

[0130] Then, it can be determined whether the first distribution information of the first target characteristic nuclide indicates that the first target characteristic nuclide originates from the object to be detected. If the first distribution information of the first target characteristic nuclide indicates that the first target characteristic nuclide originates from the object to be detected, it can be determined that the object to be detected is a target type object. On the contrary, if the first distribution information of the first target characteristic nuclide indicates that the first target characteristic nuclide does not originate from the object to be detected, such as from a detection device, a tool, etc., it can be determined that the object to be detected is not a target type object.

[0131] In this way, based on the gamma-ray energy spectrum, combined with the first distribution information of the first target characteristic nuclide on the nuclide space distribution map, it is determined whether the first target characteristic nuclide originates from the object to be detected, so as to determine whether the object to be detected is a target type object. This can avoid false detection caused by the content of the first target characteristic nuclide other than the object to be detected meeting the content of the target type object, thereby further improving the accuracy of the detection result.

[0132] In some embodiments, the object to be detected can be detected in combination with the two-dimensional nuclide spatial distribution map to determine whether the object to be detected is a target type object. Accordingly, the specific implementation of the above step S330 can be as follows:

[0133] Selecting a first target characteristic hotspot on a two-dimensional nuclide spatial distribution map;

[0134] Determine the first characteristic nuclide composition corresponding to the first target characteristic hot spot on the gamma-ray energy spectrum;

[0135] Selecting a second target characteristic nuclide from the first characteristic nuclide composition;

[0136] Determine second distribution information of the second target characteristic nuclide in the first target characteristic hotspot;

[0137] When the second distribution information represents that the second target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

[0138] The first target characteristic hotspot is a hotspot selected from the two-dimensional nuclide spatial distribution map. The hotspot may be an area with a density higher than a first preset threshold and / or an energy intensity higher than a second preset threshold. The first preset threshold and the second preset threshold may be set according to actual needs.

[0139] The first characteristic nuclide composition is the nuclide composition corresponding to the first target characteristic hot spot on the gamma-ray energy spectrum.

[0140] The second target characteristic nuclide is a target characteristic nuclide selected from the first characteristic nuclide composition. The characteristic nuclide may be a characteristic nuclide whose content is greater than or equal to the minimum content of the target type object.

[0141] Specifically, when detecting an object to be detected, a first target characteristic hotspot can be selected on the two-dimensional nuclide spatial distribution map of the object to be detected, and the gamma ray corresponding to the hotspot is projected onto the gamma ray energy spectrum map to obtain the gamma ray energy spectrum corresponding to the first target characteristic hotspot. Figure 5 As an illustration, the gamma-ray energy spectrum corresponding to the first target characteristic hotspot can be shown as gamma-ray energy spectrum diagram-1 and gamma-ray energy spectrum diagram-2. Then, the first characteristic nuclide composition corresponding to the first target characteristic hotspot can be determined on the gamma-ray energy spectrum diagram. Figure 5 As an illustration, the contents of each characteristic nuclide shown in the gamma-ray energy spectrum diagram-1 and the gamma-ray energy spectrum diagram-2 may be composed of the first characteristic nuclide corresponding to the first target characteristic hotspot.

[0142] Afterwards, a second target characteristic nuclide may be selected from the first characteristic nuclide composition, and second distribution information of the second target characteristic nuclide in the first target characteristic hotspot may be determined. Figure 5 , the second distribution information can be as follows Figure 5 Then, it can be determined whether the second distribution information of the second target characteristic nuclide indicates that the second target characteristic nuclide originates from the object to be detected. If the second distribution information of the second target characteristic nuclide indicates that the second target characteristic nuclide originates from the object to be detected, it can be determined that the object to be detected is a target type object. On the contrary, if the second distribution information of the second target characteristic nuclide indicates that the second target characteristic nuclide does not originate from the object to be detected, it can be determined that the object to be detected is not a target type object.

[0143] In this way, a hot spot is selected from the two-dimensional nuclide distribution map to obtain the gamma-ray spectrum of the hot spot, and then a second target characteristic nuclide is selected from the gamma-ray spectrum to obtain the second distribution information from the two-dimensional nuclide distribution map. The hot spot distribution in the two-dimensional nuclide spatial distribution map and the gamma-ray spectrum corresponding to the hot spot can be combined to detect the object to be detected more specifically, thereby further improving the accuracy and efficiency of the detection results.

[0144] In some embodiments, the object to be detected can be detected in combination with the three-dimensional nuclide spatial distribution map to determine whether the object to be detected is a target type object. Accordingly, the specific implementation of the above step S330 can be as follows:

[0145] Constructing a three-dimensional nuclide spatial distribution map of the object to be detected based on the two-dimensional nuclide spatial distribution map of each section of the object to be detected;

[0146] Selecting a second target characteristic hotspot on the three-dimensional nuclide spatial distribution map;

[0147] Determining the second characteristic nuclide composition corresponding to the second target characteristic hotspot on the gamma-ray energy spectrum corresponding to the second target characteristic hotspot;

[0148] Selecting a third target characteristic nuclide from the second characteristic nuclide composition;

[0149] Determine third distribution information of the third target characteristic nuclide in the second target characteristic hotspot;

[0150] When the third distribution information represents that the third target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

[0151] The second target feature hotspot is a hotspot selected on the three-dimensional nuclide spatial distribution diagram of the object to be detected.

[0152] The second characteristic nuclide composition is the characteristic nuclide composition corresponding to the second target characteristic hotspot.

[0153] The third target characteristic nuclide is a target characteristic nuclide selected from the second characteristic nuclide composition.

[0154] The third distribution information is the distribution information of the third target characteristic nuclide in the second target characteristic hotspot.

[0155] Specifically, when inspecting the object to be inspected, a three-dimensional nuclide spatial distribution map of the object to be inspected can be constructed based on the two-dimensional nuclide spatial distribution map of each section of the object to be inspected. For example, the two-dimensional nuclide spatial distribution map of each section can be fitted in sequence to obtain a three-dimensional nuclide spatial distribution map. Then, a second target characteristic hotspot can be selected from the three-dimensional nuclide spatial distribution map, and the gamma ray corresponding to the second target characteristic hotspot can be projected onto the gamma ray energy spectrum to obtain the gamma ray energy spectrum corresponding to the second target characteristic hotspot. Figure 6 As an illustration, the gamma-ray energy spectrum corresponding to the second target characteristic hotspot can be as follows: Figure 6 The gamma-ray energy spectrum diagram in Figure 3 is shown in Figure 3. According to the gamma-ray energy spectrum diagram corresponding to the second target characteristic hotspot, the second characteristic nuclide composition corresponding to the second target characteristic hotspot can be obtained.

[0156] Then, a third target characteristic nuclide can be selected from the second characteristic nuclide composition, and the third distribution information of the third target characteristic nuclide can be determined in the three-dimensional nuclide spatial distribution map. Determine whether the third distribution information of the third target characteristic nuclide represents that the third target characteristic nuclide originates from the object to be detected. If the third distribution information of the third target characteristic nuclide represents that the third target characteristic nuclide originates from the object to be detected, it can be determined that the object to be detected is a target type object. Conversely, if the third distribution information of the third target characteristic nuclide represents that the third target characteristic nuclide does not originate from the object to be detected, it can be determined that the object to be detected is not a target type object.

[0157] It can be understood that the entire gamma-ray energy spectrum after the inspection object is scanned can also be used for nuclide identification, and the target characteristic nuclides of concern can be marked and projected onto a three-dimensional nuclide spatial distribution map, so that it can be observed where the indicative nuclides come from and whether they are concentrated in the inspected object.

[0158] In this way, a hot spot is selected from the three-dimensional nuclide distribution map to obtain the gamma-ray energy spectrum of the hot spot, and then a third target characteristic nuclide is selected from the gamma-ray energy spectrum to obtain the third distribution information from the three-dimensional nuclide distribution map. The hot spot distribution in the two-dimensional nuclide spatial distribution map and the gamma-ray energy spectrum corresponding to the hot spot can be combined to detect the object to be detected more specifically. Moreover, the three-dimensional nuclide spatial distribution map can more intuitively and clearly display the distribution information of the reaction hot spot and the target characteristic nuclide, so that the interference of equipment other than the object to be detected on the object to be detected can be further avoided, and the accuracy of the detection result can be further improved.

[0159] In some embodiments, before step S310, the following steps may also be included:

[0160] The neutron beam is collimated to obtain a neutron beam of a preset shape, and the neutron beam of the preset shape is used to irradiate the object to be detected.

[0161] The neutron beam is collimated to a neutron beam of a preset shape, and the warehouse clerk collimates the neutron beam into a fan-shaped neutron beam. The neutron beam of the preset shape can be used to irradiate the object to be detected. In this way, the neutron beam can be more efficiently irradiated to the object to be detected, thereby improving the detection efficiency.

[0162] In some embodiments, the following steps may be further included before collimating the neutron beam:

[0163] Moder the neutron beam to obtain a thermal neutron beam;

[0164] Accordingly, the thermal neutron beam can be collimated to obtain a thermal neutron beam of a preset shape, and the thermal neutron beam of the preset shape is used to irradiate the object to be detected.

[0165] By slowing down the neutron beam, the speed of the neutron beam can be gradually reduced to become a thermal neutron beam. Then, the thermal neutron beam is collimated to obtain a thermal neutron beam of a preset shape, and the thermal neutron beam of the preset shape is used to irradiate the object to be detected. In this way, slowing down the neutron beam to become a thermal neutron beam can improve the collimation effect of the thermal neutron beam, thereby improving the detection effect of the object detection method.

[0166] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0167] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), appropriate firmware, plug-in, function card, etc. When implemented in software, the elements of the present application are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or communication link by a data signal carried in a carrier. "Machine-readable medium" may include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (Radio Frequency, RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0168] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0169] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0170] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. An object detection method, characterized in that: include: Acquiring ray characteristic information of gamma rays emitted by the object to be detected when irradiated by a neutron beam; Processing the ray characteristic information of the gamma ray to obtain a gamma ray energy spectrum diagram and a nuclide spatial distribution diagram of the object to be detected; determining whether the object to be detected is a target type object according to the gamma-ray energy spectrum and the nuclide spatial distribution map; In the case where the nuclide spatial distribution map is a two-dimensional nuclide spatial distribution map, determining whether the object to be detected is a target type object according to the gamma-ray energy spectrum map and the nuclide spatial distribution map includes: Selecting a first target characteristic hotspot on the two-dimensional nuclide spatial distribution map, wherein the first target characteristic hotspot is an area with a density higher than a first preset threshold and / or an energy intensity higher than a second preset threshold; Determining a first characteristic nuclide composition corresponding to the first target characteristic hotspot on the gamma-ray energy spectrum; Selecting a second target characteristic nuclide from the first characteristic nuclide composition; Determining second distribution information of the second target characteristic nuclide in the first target characteristic hotspot; When the second distribution information indicates that the second target characteristic nuclide originates from the object to be detected, determining that the object to be detected is a target type object; In the case where the nuclide spatial distribution map is a three-dimensional nuclide spatial distribution map, determining whether the object to be detected is a target type object according to the gamma-ray energy spectrum map and the nuclide spatial distribution map includes: Constructing a three-dimensional nuclide spatial distribution map of the object to be detected based on the two-dimensional nuclide spatial distribution map of each section of the object to be detected; Selecting a second target characteristic hotspot on the three-dimensional nuclide spatial distribution map; Determining a second characteristic nuclide composition corresponding to the second target characteristic hotspot on a gamma-ray energy spectrum corresponding to the second target characteristic hotspot; Selecting a third target characteristic nuclide from the second characteristic nuclide composition; Determining third distribution information of the third target characteristic nuclide in the second target characteristic hotspot; When the third distribution information represents that the third target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

2. The method according to claim 1, characterized in that The step of obtaining the ray characteristic information of the gamma rays emitted by the object to be detected when irradiated by the neutron beam includes: Performing a first detection and a second detection on each cross section of the object to be detected to obtain first ray characteristic information and second ray characteristic information of the gamma ray of the object to be detected, wherein an angle between the encoding plate when performing the first detection and the encoding plate when performing the second detection is less than or equal to ninety degrees; Processing the ray characteristic information of the gamma ray to obtain a nuclide spatial distribution map of the object to be detected includes: The first ray characteristic information and the second ray characteristic information are decoded to obtain a nuclide spatial distribution map of the object to be detected.

3. The method according to claim 1, characterized in that Before acquiring the ray characteristic information of the gamma ray emitted by the object to be detected when irradiated by the neutron beam, the method further includes: The neutron beam is collimated to obtain a neutron beam of a preset shape, and the neutron beam of the preset shape is used to irradiate the object to be detected.

4. The method according to claim 3, characterized in that Before the neutron beam is collimated to obtain a neutron beam of a preset shape, the method further includes: moderating the neutron beam to obtain a thermal neutron beam; The step of collimating the neutron beam to obtain a neutron beam of a preset shape comprises: The thermal neutron beam is collimated to obtain a thermal neutron beam of a preset shape, and the thermal neutron beam of the preset shape is used to irradiate the object to be detected.

5. An object detection system, characterized in that: Including neutron ray source, gamma camera and detection device: The neutron ray source is used to generate a neutron beam, and the neutron beam is used to irradiate the object to be detected; The gamma camera is used to obtain ray characteristic information of gamma rays emitted by the object to be detected when irradiated by the neutron beam; Processing the ray characteristic information of the gamma ray to obtain a gamma ray energy spectrum diagram and a nuclide spatial distribution diagram of the object to be detected; The detection device is used to determine whether the object to be detected is a target type object according to the gamma-ray energy spectrum and the nuclide spatial distribution map; Wherein, when the nuclide spatial distribution diagram is a two-dimensional nuclide spatial distribution diagram, the detection device is specifically used for: Selecting a first target characteristic hotspot on the two-dimensional nuclide spatial distribution map, wherein the first target characteristic hotspot is an area with a density higher than a first preset threshold and / or an energy intensity higher than a second preset threshold; Determining a first characteristic nuclide composition corresponding to the first target characteristic hotspot on the gamma-ray energy spectrum; Selecting a second target characteristic nuclide from the first characteristic nuclide composition; Determining second distribution information of the second target characteristic nuclide in the first target characteristic hotspot; When the second distribution information indicates that the second target characteristic nuclide originates from the object to be detected, determining that the object to be detected is a target type object; In the case where the nuclide spatial distribution diagram is a three-dimensional nuclide spatial distribution diagram, the detection device is specifically used to: Constructing a three-dimensional nuclide spatial distribution map of the object to be detected based on the two-dimensional nuclide spatial distribution map of each section of the object to be detected; Selecting a second target characteristic hotspot on the three-dimensional nuclide spatial distribution map; Determining a second characteristic nuclide composition corresponding to the second target characteristic hotspot on a gamma-ray energy spectrum corresponding to the second target characteristic hotspot; Selecting a third target characteristic nuclide from the second characteristic nuclide composition; Determining third distribution information of the third target characteristic nuclide in the second target characteristic hotspot; When the third distribution information represents that the third target characteristic nuclide originates from the object to be detected, it is determined that the object to be detected is a target type object.

6. The system according to claim 5, characterized in that The gamma camera is a coding plate gamma camera; the coding plate gamma camera comprises a detector array, a coding plate, a coding plate rotating device, and a decoding device; The detector array is used for: Performing first detection and second detection on the gamma rays emitted from each section of the object to be detected and penetrating the encoding plate, to obtain first ray characteristic information and second ray characteristic information of the gamma rays of the object to be detected; The coding plate rotating device is used for: Control the angle between the encoding plate when performing the first detection and the encoding plate when performing the second detection to be less than or equal to ninety degrees; Decoding means for: The first ray characteristic information and the second ray characteristic information are decoded to obtain a nuclide spatial distribution map of the object to be detected.

7. The system according to claim 6, characterized in that The system also includes a collimator; The input end of the collimator is connected to the output end of the neutron ray source, and is used to collimate the neutron beam into a neutron beam of a preset shape, and output the neutron beam of the preset shape to irradiate the object to be inspected.

8. The system according to claim 7, characterized in that The system also includes a moderator; The input end of the moderator is connected to the output end of the neutron ray source, and the output end of the moderator is connected to the input end of the collimator; The moderator is used to moderate the neutron beam into a thermal neutron beam, and input the thermal neutron beam into the collimator; The collimator is used to collimate the thermal neutron beam to obtain a thermal neutron beam with a preset shape.

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