Radiation inspection system

Abstract

The invention provides a radiation inspection system, which comprises a plurality of scanning devices, the plurality of scanning devices are arranged around an inspection channel so as to scan an inspected object in the inspection channel from different angles, each scanning device comprises a radiation source, a flywheel and a back scattering detector, the flywheel is rotatably arranged and is provided with a collimation port, and the back scattering detector is arranged on the radiation source. The scanning devices are arranged on the back scattering detector and matched with the radiation source and the back scattering detector to carry out flying spot back scattering scanning on a detected object, the radiation source of each scanning device is a pulse radiation source, and the radiation sources of the scanning devices do not emit beams at the same time. Therefore, a plurality of scanning devices can conveniently carry out flying spot back scattering scanning on the detected object at different times.

Description

Technical Field

[0001] The present application relates to the technical field of radiation inspection, and in particular to a radiation inspection system. Background Art

[0002] Some radiation inspection systems use multiple scanning devices to perform flying spot backscatter scanning on the inspected object at multiple viewing angles. In this case, in order to prevent mutual interference between different scanning devices, the multiple scanning devices usually do not perform flying spot backscatter scanning on the inspected object at the same time.

[0003] In the related art, the rotation speed and phase of the flywheel of each scanning device are generally controlled so that the radiation source of each scanning device does not pass through its own flywheel at the same time, so that multiple scanning devices do not scan the object to be inspected at the same time. However, this control method is difficult and costly. Summary of the invention

[0004] The present application aims to provide a radiation inspection system to facilitate multiple scanning devices to perform flying spot backscatter scanning on an object to be inspected at different times.

[0005] In order to achieve the above objectives, the present application provides a radiation inspection system, which includes:

[0006] A plurality of scanning devices are arranged around the inspection channel to scan the inspected object in the inspection channel from different angles. Each scanning device comprises a ray source, a flywheel and a backscatter detector. The flywheel is rotatably arranged and has a collimation port to cooperate with the ray source and the backscatter detector to perform flying point backscatter scanning on the inspected object. The ray source of each scanning device is a pulse ray source, and the ray sources of each scanning device do not emit beams at the same time.

[0007] In some embodiments, one of the plurality of scanning devices is a first scanning device, and the radiation inspection system further comprises:

[0008] A trigger component configured to send a signal when the flywheel of the first scanning device rotates to the alignment port; and

[0009] The controller is connected to the trigger component and multiple scanning devices by signal so as to receive the signal of the trigger component, and when the signal of the trigger component is received and the ray sources of other scanning devices other than the first scanning device have not emitted beams, the controller controls the ray source of the first scanning device to emit beams so that the rays emitted by the ray source of the first scanning device pass through the collimation port, and controls the ray sources of other scanning devices other than the first scanning device to emit beams in sequence after the ray source of the first scanning device emits beams, so that the ray sources of each scanning device do not emit beams at the same time.

[0010] In some embodiments, the trigger component includes a first trigger member and a second trigger member. The first trigger member is arranged on the flywheel of the first scanning device and is located at the alignment port of the flywheel of the first scanning device. The second trigger member is arranged outside the flywheel of the first scanning device and rotates relative to the first trigger member to cooperate with the first trigger member to send a signal when the flywheel of the first scanning device rotates to the alignment port.

[0011] In some embodiments, the trigger component includes a photoelectric switch, a magnetic induction switch, a magnetically controlled switch, a travel switch, a grating ruler, an encoder or a visual detection component; and / or, the radiation inspection system includes only one trigger component.

[0012] In some embodiments, the ray sources of each scanning device pulse beams according to their respective preset beam emission frequencies, and the beam emission timings of the ray sources of each scanning device are staggered so that the ray sources of each scanning device do not emit beams at the same time. In some embodiments, the preset beam emission frequencies of the ray sources of each scanning device are the same or different.

[0013] In some embodiments, at least one scanning device includes a transmission detector, which cooperates with a radiation source to perform a transmission scan on the object under inspection.

[0014] In some embodiments, part or all of the scanning devices further include an angle detection component, which detects the rotation angle of the flywheel when the radiation source emits a beam.

[0015] In some embodiments, the angle detection component includes an angle sensor, an encoder, a grating ruler or a visual detection component.

[0016] In some embodiments, the radiation inspection system includes at least three scanning devices.

[0017] By setting the ray sources of multiple scanning devices performing multi-view flying spot backscatter scanning as pulse ray sources and making each ray source emit beams in time, it is convenient for multiple scanning devices to perform flying spot backscatter scanning on the object to be inspected at different times.

[0018] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1This is a simplified structural diagram of the radiation inspection system in the first embodiment of the present application.

[0021] Figure 2 This is a simplified structural diagram of the flywheel of the first scanning device in the first embodiment of the present application.

[0022] Figure 3 This is a simplified structural diagram of the flywheel of the second scanning device in the first embodiment of the present application.

[0023] Figure 4 Schematic diagram of the beam-emitting relationship between the first ray source and the second ray source in the second embodiment of the present application.

[0024] Figure 5 This is a simplified structural diagram of the radiation inspection system in the third embodiment of the present application. Description of reference numerals:

[0025] 10. Scanning device; 101. First scanning device; 102. Second scanning device;

[0026] 1. ray source; 11. first ray source; 12. second ray source;

[0027] 2. flywheel; 23. collimation port; 24. angle detection component; 25. trigger component; 26. first trigger component;

[0028] 3. Backscatter detector;

[0029] 4. Check the channel;

[0030] 5. The subject of inspection. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without carrying out creative work are within the scope of protection of this application.

[0032] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0033] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0034] In the description of the present application, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present application.

[0035] In the present application, unless otherwise specified, “plurality” means at least two, that is, including cases of two and at least three.

[0036] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0037] Radiation inspection system is a device that uses scanning devices to scan and inspect objects such as vehicles, containers and aircraft in customs and airports to obtain images. From the perspective of imaging principle, scanning devices are mainly divided into transmission type, backscatter type and transmission-backscatter combination type.

[0038] Among them, backscatter imaging technology uses the Compton scattering effect to capture the photons reflected by the object under inspection. The scattered image is formed by the radiation signal scattered by the object at a certain depth close to the backscatter detector. Since the Compton scattering of radiation in low atomic number materials such as explosives and drugs is stronger, backscatter imaging technology can distinguish materials and highlight organic substances. It has the advantages of low radiation dose, sensitivity to light materials, and intuitive images.

[0039] Flying spot backscatter imaging technology is a typical backscatter imaging technology. Figure 1A scanning device 10 using a flying spot backscatter imaging technique generally includes a ray source 1, a flywheel 2, and a backscatter detector 3. The ray source 1 is disposed on one side of an object 5 to be inspected, and is used to emit rays to the object 5 to be inspected. The flywheel 2 is rotatably disposed between the ray source 1 and the object 5 to be inspected, and has a collimation port 23 for the rays to pass through, so that a fan-shaped light beam emitted from the ray source 1 to the object 5 to be inspected forms a fine light beam (i.e., a flying spot), and the corresponding fine light beam irradiates the object 5 to generate backscattered rays. The backscatter detector 3 is disposed on the same side of the object 5 to be inspected, and receives the backscattered rays generated by the fine light beam irradiating the object 5 to be inspected, converts the optical signal into an electrical signal, and reconstructs the image by the imaging device.

[0040] In order to realize the flying spot backscatter scanning at different angles of the object under inspection 5, see Figure 2 and Figure 4 In some radiation inspection systems, a plurality of scanning devices 10 are provided, and the plurality of scanning devices 10 are arranged around the inspection channel 4 to perform flying spot backscatter scanning on the inspected object 5 located in the inspection channel 4 from different angles, thereby forming a multi-viewing angle (i.e., at least two viewing angles) flying spot backscatter scanning system.

[0041] For the above-mentioned multi-view flying spot backscatter scanning system, in order to prevent mutual interference between different scanning devices 10 and affect the imaging quality, it is usually required that the scanning devices 10 scan the object 5 at different times.

[0042] In the related art, the rotation speed and phase of the flywheel 2 of each scanning device 10 are generally controlled to prevent the multiple scanning devices 10 from performing flying spot backscatter scanning on the object 5 at the same time. Specifically, the rotation speed of the motor driving each flywheel 2 is generally controlled to match the rotation speeds of the flywheels 2. For example, the rotation speeds of the flywheels 2 are synchronized in time division, so that the ray sources 1 of each scanning device 10 do not emit rays from the flywheel 2 at the same time, and thus the multiple scanning devices 10 do not perform flying spot backscatter scanning on the object 5 at the same time. Moreover, it is necessary to make the time period deviation of each flywheel emitting rays have a fixed phase relationship.

[0043] However, it is difficult and costly to match the rotational speed and phase between different flywheels 2. In addition, due to the constraints of motor stability, the rotational speed of the flywheel 2 is difficult to remain constant for a long time and is prone to change. Even if the rotational speeds of different flywheels 2 can be matched well, the rotational speeds of some flywheels 2 may change during subsequent work, causing some scanning devices 10 to scan the object 5 at the same time, interfering with each other and affecting imaging. This further increases the control difficulty and increases the control cost.

[0044] The above problem becomes more serious when the speed of the flywheel 2 is higher. That is to say, the higher the speed of the flywheel 2, the more difficult it is to control, the higher the cost, and the higher the requirements for the motor. This also limits the increase in the speed of the flywheel 2 and affects the efficiency.

[0045] It can be seen that it is difficult to conveniently realize the flying spot backscatter scanning of the inspected object 5 at different times by each scanning device 10 by matching the rotation speeds of different flywheels 2, which affects the inspection accuracy and efficiency.

[0046] In view of the above situation, the present application provides a radiation inspection system.

[0047] Figure 1-Figure 5 The structure of the radiation inspection system in the present application is shown exemplarily.

[0048] See also Figure 1-Figure 5 In the present application, the radiation inspection system includes a plurality of scanning devices 10, which are arranged around an inspection channel 4 to scan an object 5 to be inspected in the inspection channel 4 from different angles. Each scanning device 10 includes a radiation source 1, a flywheel 2 and a backscatter detector 3. The flywheel 2 is rotatably arranged and has a collimation port 23 to cooperate with the radiation source 1 and the backscatter detector 3 to perform flying point backscatter scanning on the object 5 to be inspected. The radiation source 1 of each scanning device 10 is a pulse radiation source, and the radiation source 1 of each scanning device 10 does not emit beams at the same time.

[0049] In the above scheme, since the scanning device 10 includes a radiation source 1, a flywheel 2 and a backscatter detector 3 that cooperate with each other to perform flying spot backscatter scanning on the inspected object 5, and the radiation inspection system includes a plurality of scanning devices 10 arranged around the inspection channel 4, the radiation inspection system is a multi-view flying spot backscatter scanning system. Moreover, since the radiation source 1 of each scanning device 10 is a pulse radiation source, and the radiation source 1 of each scanning device 10 does not emit beams at the same time, it is only necessary to control the beam emission timing of each radiation source 1 without controlling the rotation speed and phase matching between the flywheels 2, so that each scanning device 10 can be controlled to perform flying spot backscatter scanning on the inspected object 5 at different times (or called time-sharing or staggered times). Therefore, the control difficulty and cost can be effectively reduced, so that it is more convenient to make multiple scanning devices 10 perform flying spot backscatter scanning on the inspected object 5 at different times. Not only can the image quality of multi-view flying spot backscatter scanning be effectively improved based on a simpler control process and lower cost, and the accuracy of the inspection result be improved, but also, the matching of the rotation speed and phase between the flywheels 2 is not controlled, that is, the time-sharing scanning of each scanning device 10 performing the flying spot backscatter scanning is realized, and the control requirements for the rotation speed of the flywheel 2 can also be reduced. On the one hand, it is convenient to adjust the rotation speed of the flywheel 2 according to the real-time relative moving speed between the inspected object 5 and the radiation inspection system, so that the rotation speed of the flywheel 2 is more matched with the relative moving speed of the inspected object 5 and the radiation inspection system, and a more accurate scanning inspection process is realized. On the other hand, even if the rotation speed of the flywheel 2 is accelerated, it will not increase the control difficulty of the scanning devices 10 emitting beams at different times. Therefore, it is also beneficial to increase the rotation speed of the flywheel 2, improve the working efficiency of the radiation inspection system, and improve the image quality.

[0050] Among them, the radiation source 1 of each scanning device 10 is a pulse radiation source. Since the pulse radiation source is a non-continuous beam-emitting radiation source, its high beam level and low beam level appear alternately in sequence. Therefore, when each radiation source 1 is a pulse radiation source, it is more convenient to stagger the beam emission timing of different radiation sources 1 to achieve different beam emission between different radiation sources 1.

[0051] It can be seen that by setting the radiation source 1 of multiple scanning devices 10 performing multi-angle flying spot backscatter scanning as a pulse radiation source and making each radiation source 1 emit beams in time, multi-angle time-sharing flying spot backscatter scanning can be easily achieved, effectively improving the inspection accuracy and inspection efficiency.

[0052] Different methods can be used to enable the ray source 1 of each scanning device 10 in the present application to emit beams in a time-sharing manner.

[0053] For example, see Figure 1-Figure 3 In some embodiments, in order to make the radiation source 1 of each scanning device 10 emit beams in a time-sharing manner, the radiation inspection system further includes a trigger component 25 and a controller (not shown).

[0054] For the convenience of description, one scanning device 10 among the plurality of scanning devices 10 is referred to as a first scanning device 101 .

[0055] The trigger component 25 is configured to send a signal when the flywheel 2 of the first scanning device 101 rotates to the collimation port 23. Here and in the following text, "at the collimation port 23" includes both the situation of being exactly at the collimation port 23 and the situation of not being exactly at the collimation port 23 but at a preset distance in front of the collimation port 23 (i.e., upstream in the rotation direction of the flywheel 2), as long as the rays emitted by the ray source 1 of the first scanning device 101 can pass through the corresponding collimation port 23 when the trigger component 25 sends a signal.

[0056] The controller is signal-connected with the trigger component 25 and multiple scanning devices 10 to receive the signal of the trigger component 25, and when receiving the signal of the trigger component 25 and the ray source 1 of other scanning devices 10 other than the first scanning device 101 has not emitted a beam, the controller controls the ray source 1 of the first scanning device 101 to emit a beam (i.e., emit rays), so that the rays emitted by the ray source 1 of the first scanning device 101 pass through the collimation port 23, and controls the ray sources 1 of other scanning devices 10 other than the first scanning device 101 to emit beams in sequence after the ray source 1 of the first scanning device 101 emits a beam, so that the ray sources 1 of each scanning device 10 do not emit beams at the same time.

[0057] In the above scheme, since the radiation sources 1 of each scanning device 10 for performing multi-angle flying spot backscatter scanning are controlled by the trigger component 25 and the controller to emit beams in sequence, it is only necessary to rotate the flywheel 2 of the first scanning device 101 to trigger the trigger component 25 and send a signal to the controller, and the controller can control each scanning device 10 to perform flying spot backscatter scanning on the object to be inspected 5 at different times (or in different times or staggered times), without the need to control the matching of the rotation speed and phase between the flywheels 2. Therefore, the control difficulty and cost can be effectively reduced, so that multiple scanning devices 10 can be more conveniently made to perform flying spot backscatter scanning on the object to be inspected 5 at different times. Scattered scanning, in this way, not only can the image quality of multi-angle flying spot backscattered scanning be effectively improved based on a simpler control process and lower cost, and the accuracy of the inspection result be improved, but also the control requirements for the rotation speed of the flywheel 2 can be reduced. On the one hand, it is convenient to adjust the rotation speed of the flywheel 2 according to the real-time relative movement speed between the inspected object 5 and the radiation inspection system, so that the rotation speed of the flywheel 2 is more matched with the relative movement speed of the inspected object 5 and the radiation inspection system, and a more accurate scanning inspection process is achieved. On the other hand, it is also conducive to increasing the rotation speed of the flywheel 2, improving the working efficiency of the radiation inspection system, and improving the image quality.

[0058] Since the different beam emission of each ray source 1 is triggered by the external trigger component 25, this beam emission mode that requires external triggering to stagger the beam emission timings of each ray source 1 can be called an externally triggered time-sharing (or staggered) beam emission mode. The corresponding externally triggered time-sharing beam emission mode is used to make each ray source 1 emit beams at different times. Since there is no need to perform too many program settings on the beam emission timing of the ray source 1 in advance, the control process is relatively simple.

[0059] It can be seen that by setting the trigger component 25 and the controller to control the time-sharing beam emission of the ray sources 1 of multiple scanning devices 10 for multi-angle flying spot backscatter scanning, multi-angle time-sharing flying spot backscatter scanning can be easily realized, effectively improving the inspection accuracy and inspection efficiency.

[0060] In order to enable the trigger component 25 to send a signal when the flywheel 2 of the first scanning device 101 rotates to the alignment port 23, see Figure 2 In some embodiments, the trigger component 25 includes a first trigger component 26 and a second trigger component (not shown). The first trigger component 26 is disposed on the flywheel 2 of the first scanning device 101 and is located at the collimation port 23 of the flywheel 2 of the first scanning device 101. The second trigger component is disposed outside the flywheel 2 of the first scanning device 101 (for example, disposed on a fixed bracket outside the flywheel 2), and rotates relative to the first trigger component 26, so that when the flywheel 2 of the first scanning device 101 rotates to the collimation port 23, it cooperates with the first trigger component 26 to send a signal. In this way, every time the flywheel 2 rotates one circle and reaches the collimation port 23, the first trigger component 26 and the second trigger component meet once and send a signal once, so that the trigger component 25 can conveniently send a signal when the flywheel 2 of the first scanning device 101 rotates to the collimation port 23, and the corresponding external trigger time-sharing beam-emitting mode is smoothly realized.

[0061] As an example, the trigger component 25 includes a photoelectric switch, a magnetic induction switch, a magnetically controlled switch, a travel switch or a grating ruler. At this time, the structure of the trigger component 25 is relatively simple, and when the flywheel 2 of the first scanning device 101 rotates to the collimation port 23, it can reliably send a signal to trigger the ray source 1 of the first scanning device 101 to emit a beam (referred to as a beam-emission trigger function).

[0062] In some embodiments, the trigger component 25 not only has a beam-emitted triggering function, but also has an angle detection function, and can detect the rotation angle of the flywheel 2 when the ray source 1 emits a beam. For example, when the trigger component 25 includes a grating ruler, an encoder, or a visual detection component (such as a CMOS or a CCD), the trigger component 25 can have both beam-emitted triggering and angle detection functions, and can not only trigger the ray source 1 of the first scanning device 101 to emit a beam, but also detect the rotation angle of the flywheel 2 when the ray source 1 of the first scanning device 101 emits a beam. Since the rotation angle information of the flywheel 2 when the ray source 1 emits a beam is used in image reconstruction, it can facilitate image determination. Therefore, using the trigger component 25 to detect the rotation angle of the flywheel 2 when the ray source 1 of the first scanning device 101 emits a beam can reduce the difficulty of imaging and improve the imaging quality.

[0063] See also Figure 2 and Figure 3 In some embodiments, the radiation inspection system includes only one trigger component 25. In this case, only the first scanning device 101 is equipped with a trigger component 25, and the first scanning device 101 is only equipped with one trigger component 25. In this way, only the radiation source 1 of the first scanning device 101 emits a beam under the triggering of the trigger component 25, and the radiation sources 1 of other scanning devices 10 do not emit a beam under the triggering of the trigger component 25, but only emit a beam under the control of the controller. In addition, the radiation source 1 of the first scanning device 101 is only triggered once by the trigger component 25 and emits a beam once during each rotation of the flywheel 2. Therefore, the entire control process is simpler and more convenient to control multiple scanning devices 10, especially the radiation sources 1 of more than three scanning devices 10 emit beams in a time-sharing manner.

[0064] For example, see Figure 4 In some embodiments, in order to make the ray source 1 of each scanning device 10 emit beams at different times, the ray source 1 of each scanning device 10 emits beams in pulses according to its own preset beam emission frequency, and the beam emission timing of the ray source 1 of each scanning device 10 is staggered, so that the ray source 1 of each scanning device 10 does not emit beams at the same time.

[0065] In the above scheme, the ray source 1 of each scanning device 10 that performs multi-angle flying spot backscatter scanning performs pulse beam emission according to its own preset beam emission frequency, and the beam emission timing of the ray source 1 of each scanning device 10 is staggered. Therefore, it is only necessary to control the beam emission timing of each ray source 1 without controlling the rotation speed and phase matching between the flywheels 2, so that each scanning device 10 can be controlled to perform flying spot backscatter scanning on the object to be inspected 5 at different times (or in different times or staggered times). Therefore, the control difficulty and cost can be effectively reduced, so that multiple scanning devices 10 can be more conveniently made to perform flying spot backscatter scanning on the object to be inspected 5 at different times. In this way, not only can the image quality of multi-angle flying spot backscatter scanning be effectively improved based on a simpler control process and lower cost, and the accuracy of the inspection results be improved, but also the control requirements for the rotation speed of the flywheel 2 can be reduced. On the one hand, it is convenient to adjust the rotation speed of the flywheel 2 according to the real-time relative movement speed between the inspected object 5 and the radiation inspection system, so that the rotation speed of the flywheel 2 is more matched with the relative movement speed of the inspected object 5 and the radiation inspection system, thereby realizing a more accurate scanning inspection process. On the other hand, it is also conducive to increasing the rotation speed of the flywheel 2, improving the working efficiency of the radiation inspection system, and improving the image quality.

[0066] Since each ray source 1 always emits a beam according to its own preset beam emission frequency, the beam emission timings of each ray source 1 are staggered, and no external triggering is required. Therefore, this beam emission method that does not require external triggering but only needs to be pre-programmed to stagger the beam emission timings of each ray source 1 can be called an internally triggered time-sharing (or staggered) beam emission method. The corresponding internally triggered time-sharing beam emission method is used to make each ray source 1 emit beams at different times. Since there is no need to additionally set a trigger component 25 to trigger the ray source 1 to emit beams, the structure is relatively simple.

[0067] It can be seen that by setting the radiation sources 1 of multiple scanning devices 10 that perform multi-angle flying spot backscatter scanning as pulse radiation sources, and making each radiation source 1 emit beams at a different time according to its own preset beam emission frequency, multi-angle time-sharing flying spot backscatter scanning can be easily achieved, effectively improving the inspection accuracy and inspection efficiency.

[0068] When the internal trigger time-sharing beam emission mode is adopted, the preset beam emission frequencies of the ray sources 1 of each scanning device 10 can be the same or different. When the preset beam emission frequencies of the ray sources 1 of each scanning device 10 are the same, the control is simpler, and it is conducive to making the beam emission of each ray source 1 more uniform, thereby achieving a better imaging effect.

[0069] In addition, when the internal trigger time-sharing beam emission mode is adopted, each ray source 1 is within the opening angle range The number of beams emitted within the range may be less than or equal to 1, or may be greater than 1. When the number of beams emitted by the ray source 1 within the range of the angle is less than or equal to 1, it indicates that the frequency of the beams emitted by the ray source 1 is low (for example, less than 60,000 Hz), and when the number of beams emitted by the ray source 1 within the range of the angle is greater than 1, it indicates that the frequency of the beams emitted by the ray source 1 is high. Compared with the former, the latter emits beams at a high frequency (for example, greater than or equal to 60,000 Hz). In this case, the imaging can be reconstructed without splicing the images, which effectively reduces the difficulty of imaging and facilitates imaging. In addition, the high frequency beam emission of the ray source 1 also facilitates that no matter how the speed of the flywheel 2 is, there is always a collimation port 23 within the range of the angle, so the control requirements for the speed of the flywheel 2 can be further reduced.

[0070] As a further improvement to the above embodiments, see Figure 2 and Figure 3 Part or all of the scanning device 10 further includes an angle detection component 24 (such as an angle sensor, an encoder, a grating ruler or a visual detection component), and the angle detection component 24 detects the rotation angle of the flywheel 2 when the ray source 1 emits a beam. In this way, the rotation angle of the flywheel 2 when the ray source 1 emits a beam can be easily determined. Since the corresponding information is used in image reconstruction, the image determination can be facilitated, and therefore, the imaging difficulty can be further reduced and the imaging quality can be improved.

[0071] Among all the scanning devices 10 , only some of the scanning devices 10 may include the angle detection component 24 , or all of the scanning devices 10 may include the angle detection component 24 .

[0072] For example, in some embodiments, the trigger component 25 only has a beam-generating triggering function and does not have an angle detection function. Each scanning device 10 including the first scanning device 101 includes an angle detection component 24, and detects the rotation angle of the flywheel 2 when the ray source 1 emits a beam through the angle detection component 24. At this time, all scanning devices 10 include the angle detection component 24, and can detect and determine the rotation angle of the corresponding flywheel 2 when each ray source 1 emits a beam, thereby reducing the difficulty of imaging and improving the imaging quality.

[0073] For another example, in some other embodiments, the trigger component 25 has both the beam-out triggering and angle detection functions, the first scanning device 101 does not include the angle detection component 24, but relies on the trigger component 25 to detect the rotation angle of the flywheel 2 when the ray source 1 emits a beam, and the other scanning devices 10 except the first scanning device 101 all include the angle detection component 24, and the rotation angle of the flywheel 2 when the ray source 1 emits a beam is detected by the angle detection component 24. At this time, only some scanning devices 10 include the angle detection component 24, specifically, the first scanning device 101 does not include the angle detection component 24, and the other scanning devices 10 all include the angle detection component 24, but each scanning device 10 can detect and determine the rotation angle of the corresponding flywheel 2 when each ray source 1 emits a beam, so that the imaging difficulty can be reduced and the imaging quality can be improved. In addition, since the first scanning device 101 only needs to be equipped with the trigger component 25, and no additional angle detection component 24 is required, it can detect and determine the rotation angle of the corresponding flywheel 2 when the ray source 1 emits a beam, so the structure is simpler.

[0074] See also Figure 2 In some embodiments, the angle detection component 24 (eg, an angle sensor) is disposed on the flywheel 2. In this way, it is more convenient to accurately detect the rotation angle of the flywheel 2, reduce the difficulty of imaging, and improve the imaging quality.

[0075] In the aforementioned embodiments, at least one scanning device 10 may include a transmission detector (not shown), which cooperates with the radiation source 1 to perform transmission scanning on the object 5 to be inspected, so that a transmission image and a backscattered image can be obtained simultaneously by using the flying spot.

[0076] For example, in some embodiments, each scanning device 10 includes a transmission detector, so that each viewing angle can obtain a transmission image and a backscattered image using a flying spot, which is beneficial to further improve the accuracy of the inspection result.

[0077] In addition, in the aforementioned embodiment, the number of scanning devices 10 in the radiation inspection system is not limited, and can be two, three or more. When the radiation inspection system includes at least three scanning devices 10, it can realize scanning of at least three viewing angles of the inspected object 5, with higher scanning accuracy, smaller error, and stronger data integrity. Moreover, compared with the case where only two scanning devices 10 are included and only two viewing angles of flying spot backscatter scanning are performed, when the radiation inspection system includes at least three scanning devices 10 and scans at least three viewing angles, it is more difficult to control the time-sharing scanning of different viewing angles by matching the rotation speed and phase between the flywheels 2. Therefore, the advantage of using the internal trigger time-sharing beam-emitting method of the present application is more obvious.

[0078] Next, combine Figure 1-Figure 5 The embodiments shown are used to further introduce the present application.

[0079] First, let’s introduce Figure 1-Figure 3 The embodiment shown.

[0080] like Figure 1 As shown, in this embodiment, the radiation inspection system has an inspection channel 4, which is formed by a bracket (such as a gantry) and is used for the inspection object 5 to pass through. In this embodiment, the inspection object 5 is a vehicle, which moves through the inspection channel 4, and the radiation inspection system does not move in the moving direction of the inspection object 5, thereby achieving relative movement between the inspection object 5 and the radiation inspection system, so that the radiation inspection system scans and inspects different parts of the inspection object 5 in the moving direction (or the length direction or depth direction of the inspection channel 4).

[0081] In this embodiment, the radiation inspection system includes two scanning devices 10, which are arranged above and to the side of the inspection channel 4, respectively, and each includes a radiation source 1, a flywheel 2 and a backscatter detector 3. The radiation source 1 and the backscatter detector 3 are arranged on the same side of the inspection channel 4, and are respectively used to emit radiation to the object 5 to be inspected in the inspection channel 4, and receive backscattered radiation reflected from the object 5 (such as a vehicle). The flywheel 2 is rotatably arranged, and collimates the radiation emitted from the radiation source 1 to the object 5 to be inspected, so as to obtain a thin beam for flying spot backscatter scanning.

[0082] For the convenience of description, the two scanning devices 10 located above and to the side of the inspection channel 4 are respectively referred to as the first scanning device 101 and the second scanning device 102, and the radiation sources 1 of the first scanning device 101 and the second scanning device 102 are respectively referred to as the first radiation source 11 and the second radiation source 12. In this embodiment, the first radiation source 11 and the second radiation source 12 are both pulse radiation sources.

[0083] Figure 2 and Figure 3 The structure of the flywheel 2 of the first scanning device 101 and the second scanning device 102 in this embodiment is further shown. Figure 2 It can be seen that in this embodiment, the flywheels 2 of the first scanning device 101 and the second scanning device 102 are provided with collimation ports 23 for the rays to pass through so as to collimate the rays. During the rotation of the flywheel 2, there is only one collimation port 23 at the same time at the ray opening angle , so that when the fan-shaped beam passes through the corresponding collimation port 23, a thin beam can be formed to perform high-speed scanning on the inspected object 5 in a plane perpendicular to the moving direction. At the same time, through the relative movement of the inspected object 5 and the radiation inspection system, a two-dimensional flying spot backscatter scanning of the inspected object 5 can be achieved, and a flying spot backscatter scanning image of the inspected object 5 can be obtained.

[0084] It can be seen that in this embodiment, the two scanning devices 10 can perform flying spot backscatter scanning at top viewing angles and side viewing angles respectively, so that the radiation inspection system becomes a dual-viewing angle flying spot backscatter scanning system.

[0085] In order to prevent the scanning processes of the two perspectives from interfering with each other, affecting the imaging quality and the accuracy of the inspection results, such as Figure 2 As shown, in this embodiment, the first scanning device 101 is equipped with a trigger component 25, and the trigger component 25 and the controller together control the first ray source 11 and the second ray source 12 to emit beams in a time-sharing manner.

[0086] Specifically, in this embodiment, the trigger component 25 is a photoelectric switch, which includes a first trigger member 26 and a second trigger member, the first trigger member 26 and the second trigger member are one and the other of the transmitter and the receiver of the photoelectric switch respectively, the first trigger member 26 is arranged on the flywheel 2 of the first scanning device 101, and is located near the alignment port 23 of the flywheel 2 of the first scanning device 10, and rotates with the flywheel 2 of the first scanning device 10 to indicate whether the corresponding flywheel 2 rotates to the vicinity of the alignment port 23, and the second trigger member is arranged on a bracket (not shown) located next to the flywheel 2 of the first scanning device 10, and is fixed. In this way, every time the flywheel 2 of the first scanning device 101 rotates one circle, the first trigger member 26 and the second trigger member meet once, and send a signal to the controller.

[0087] The controller is signal-connected to the trigger component 25 and the two scanning devices 10. After receiving the signal from the trigger component 25, the controller determines whether the second ray source 12 is emitting a beam. If the second ray source 12 is not emitting a beam, the controller controls the first ray source 11 to emit a beam. Since the trigger component 25 is located near the collimation port 23 of the flywheel 2 of the first scanning device 101, after receiving the signal from the trigger component 25, the controller controls the first ray source 11 to emit a beam. Then, the rays emitted by the first ray source 11 can pass through the collimation port 23 of the flywheel 2 of the first scanning device 101, smoothly irradiate the inspected object 5, and are received by the backscatter detector 3 of the first scanning device 101 after reflection, thereby realizing the flying spot backscatter scanning. When the first ray source 11 emits a beam, the controller controls the second ray source 12 not to emit a beam, until the first ray source 11 finishes emitting a beam, and then the controller controls the second ray source 12 to emit a beam. When the second ray source 12 emits a beam, the first ray source 11 does not emit a beam, even if the flywheel 2 of the first scanning device 101 rotates one circle and returns to the position of the first trigger member 26, the first ray source 11 does not emit a beam. Only when the second ray source 12 finishes emitting a beam and the flywheel 2 of the first scanning device 101 rotates one circle and returns to the position of the first trigger member 26, the controller controls the first ray source 11 to emit a beam again... and this cycle is repeated.

[0088] Since the radiation sources 1 of the two viewing angles can emit beams alternately in sequence under the control of the trigger component 25 and the controller, there is no need to control the rotation speed and phase matching between the two flywheels 2, so that the two radiation sources 1 can emit beams at different times during the operation of the radiation inspection system, thereby controlling the scanning of the two viewing angles to be performed at different times. Therefore, the method is simple and convenient, with low cost, and can effectively prevent the scanning of the two viewing angles from being performed simultaneously due to changes in the rotation speed and / or phase of the two flywheels 2, thereby interfering with each other and affecting the imaging. In addition, the method is beneficial to increasing the rotation speed of the flywheel 2 and improving the working efficiency of the radiation inspection system. At the same time, the method is beneficial to reducing the requirements for the motor driving the flywheel 2 to rotate, so that various types of motors can be used to drive the flywheel 2 to rotate.

[0089] like Figure 2 and Figure 3 As shown, in this embodiment, the flywheel 2 of the first scanning device 101 and the second scanning device 102 are both provided with an angle detection component 24, and the corresponding angle detection component 24 detects the rotation angle of the flywheel 2 when the ray source 1 emits a beam. In this way, the angular position information of the flywheel 2 can be accurately determined each time the ray source 1 emits a beam, thereby making image reconstruction more convenient.

[0090] Next, let’s introduce Figure 4 The embodiment shown.

[0091] like Figure 4 As shown, in this embodiment, the radiation inspection system still looks like Figure 1-Figure 3 Like the embodiment shown in the figure, it includes two scanning devices 10, namely a first scanning device 101 and a second scanning device 102 respectively located above and on the side of the inspection channel 4, and the radiation sources 1 of the first scanning device 101 and the second scanning device 102, namely the first radiation source 11 and the second radiation source 12 are still pulse radiation sources, and still emit beams in time. However, in this embodiment, the time-sharing beam emission of the first radiation source 11 and the second radiation source 12 no longer adopts an externally triggered time-sharing beam emission method based on a trigger component 25 and a controller, but adopts an internally triggered time-sharing beam emission method.

[0092] Specifically, if Figure 4 As shown, in this embodiment, the first ray source 11 and the second ray source 12 are both pulsed ray sources, and the two emit pulsed beams according to the same preset beam emission frequency, and the pulse widths of the two are equal, but the two do not emit beams at the same time, but emit beams alternately in sequence, for example, the first ray source 11 emits a beam first, when the first ray source 11 emits a beam, the second ray source 12 does not emit a beam, the first ray source 11 ends the beam emission, and the second ray source 12 emits a beam again, when the second ray source 12 emits a beam, the first ray source 11 does not emit a beam, the second ray source 12 ends the beam emission, and the first ray source 11 emits a beam again... and so on and so forth. In this case, the high and low levels of the first ray source 11 and the second ray source 12 are opposite.

[0093] Since the ray sources 1 of the two viewing angles are both pulse ray sources, and the two emit beams alternately in sequence according to the same preset beam emission frequency, it is only necessary to pre-set the beam emission timing of the two ray sources 1 in the controller so that the high and low levels of the two ray sources 1 are opposite, so that the two ray sources 1 can emit beams at different times during the operation of the radiation inspection system, thereby controlling the scanning of the two viewing angles to be performed at different times. In this case, there is no need to perform matching control of the rotation speed and phase between the two flywheels 2. Therefore, it is simple, convenient and low-cost, and can effectively prevent the scanning of the two viewing angles from being performed simultaneously due to changes in the rotation speed and / or phase of the two flywheels 2, thereby interfering with each other and affecting the imaging. In addition, it is beneficial to increase the rotation speed of the flywheel 2 and improve the working efficiency of the radiation inspection system. At the same time, it is also beneficial to reduce the requirements for the motor that drives the flywheel 2 to rotate, so that various types of motors can be used to drive the flywheel 2 to rotate.

[0094] Next, let’s introduce Figure 5 The embodiment shown. It should be noted that, Figure 5 The backscatter detector 3 of each scanning device 10 is not shown.

[0095] like Figure 5 As shown, this embodiment is similar to the aforementioned Figure 1-Figure 3 The difference between the embodiments shown is that the radiation inspection system no longer includes only two scanning devices 10, but includes more (eight in the figure as an example) scanning devices 10. In this way, the radiation inspection system can perform flying spot backscatter scanning at more viewing angles on the object 5 to be inspected, and the imaging quality is higher. However, the radiation source 1 of each scanning device 10 in this embodiment still adopts the aforementioned Figure 1-Figure 3 The external trigger time-sharing beam emission method of the embodiment shown, or Figure 4 The embodiment shown has an internally triggered time-sharing beam-emitting mode.

[0096] Generally, the more viewing angles there are, the more difficult it is to match the rotation speed and phase between the flywheels 2. For this reason, this embodiment adopts an externally triggered time-sharing beam-emitting method or an internally triggered time-sharing beam-emitting method for flying spot backscatter scanning at more viewing angles, which has a more obvious effect and is more conducive to reducing the control difficulty and cost, so that the image quality of flying spot backscatter scanning at more viewing angles can be effectively improved based on a simpler control process and cost, and the accuracy of the inspection results can be improved.

[0097] The above description is only an exemplary embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A radiation inspection system, characterized in that: include: A plurality of scanning devices (10) are arranged around an inspection channel (4) to scan an object to be inspected (5) located in the inspection channel (4) from different angles. Each of the scanning devices (10) comprises a ray source (1), a flywheel (2) and a backscatter detector (3). The flywheel (2) is rotatably arranged and has a collimation port (23) to cooperate with the ray source (1) and the backscatter detector (3) to perform flying point backscatter scanning on the object to be inspected (5). The ray source (1) of each of the scanning devices (10) is a pulsed ray source, and the ray sources (1) of each of the scanning devices (10) do not emit beams at the same time.

2. The radiation inspection system according to claim 1, characterized in that: One of the plurality of scanning devices (10) is a first scanning device (101), and the radiation inspection system further comprises: a trigger component (25) configured to send out a signal when the flywheel (2) of the first scanning device (101) rotates to the alignment port (23); and A controller is signal-connected to the trigger component (25) and the plurality of scanning devices (10) to receive a signal from the trigger component (25), and when receiving the signal from the trigger component (25) and when the ray sources (1) of other scanning devices (10) other than the first scanning device (101) have not emitted a beam, controls the ray source (1) of the first scanning device (101) to emit a beam, so that the rays emitted by the ray source (1) of the first scanning device (101) pass through the collimation port (32), and controls the ray sources (1) of other scanning devices (10) other than the first scanning device (101) to emit a beam in sequence after the ray source (1) of the first scanning device (101) emits a beam, so that the ray sources (1) of the scanning devices (10) do not emit beams at the same time.

3. The radiation inspection system according to claim 2, characterized in that: The trigger component (25) comprises a first trigger member (26) and a second trigger member, wherein the first trigger member (26) is arranged on the flywheel (2) of the first scanning device (101) and is located at the alignment port (31) of the flywheel (2) of the first scanning device (101), and the second trigger member is arranged outside the flywheel (2) of the first scanning device (101) and rotates relative to the first trigger member (26) so as to cooperate with the first trigger member (26) to send out a signal when the flywheel (2) of the first scanning device (101) rotates to the alignment port (23).

4. The radiation inspection system according to claim 2, characterized in that: The trigger component (25) includes a photoelectric switch, a magnetic induction switch, a magnetically controlled switch, a travel switch, a grating ruler, an encoder or a visual detection component; and / or the radiation inspection system includes only one trigger component (25).

5. The radiation inspection system according to claim 1, characterized in that: The ray sources (1) of each scanning device (10) emit pulsed beams according to their own preset beam emission frequencies, and the beam emission timings of the ray sources (1) of each scanning device (10) are staggered, so that the ray sources (1) of each scanning device (10) do not emit beams at the same time.

6. The radiation inspection system according to claim 5, characterized in that: The preset beam emission frequencies of the ray sources (1) of the scanning devices (10) are the same or different.

7. The radiation inspection system according to any one of claims 1 to 6, characterized in that: At least one of the scanning devices (10) comprises a transmission detector, and the transmission detector cooperates with the radiation source (1) to perform transmission scanning on the object to be inspected (5).

8. The radiation inspection system according to any one of claims 1 to 6, characterized in that: Part or all of the scanning device (10) further comprises an angle detection component (24), wherein the angle detection component (24) detects the rotation angle of the flywheel (2) when the ray source (1) emits a beam.

9. The radiation inspection system according to claim 8, characterized in that: The angle detection component (24) comprises an angle sensor, an encoder, a grating ruler or a visual detection component.

10. The radiation inspection system according to any one of claims 1 to 6, characterized in that: The radiation inspection system comprises at least three scanning devices (10).

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