CN107479103B

CN107479103B - Radiation inspection system

Info

Publication number: CN107479103B
Application number: CN201710846435.1A
Authority: CN
Inventors: 闫雄; 王少锋; 刘铮; 冯志涛; 王春雷
Original assignee: Jun He Xinda Beijing Science And Technology Ltd
Current assignee: Zhongtai Yuanke Co.,Ltd.
Priority date: 2017-09-19
Filing date: 2017-09-19
Publication date: 2020-01-14
Anticipated expiration: 2037-09-19
Also published as: CN107479103A

Abstract

The invention discloses a radiation inspection system. The radiation device is arranged at the bottom of the radiation inspection channel and is used for emitting scanning ray beams to the detection area; the detector is arranged at the top and/or the side of the radiation inspection channel and is used for receiving the imaging ray beams transmitted or scattered from the detected object in the detection area; the dragging device is arranged on one side or two sides in the radiation inspection channel and is used for dragging the detected object to move along the moving direction. The control device controls the radiation device to emit scanning beams to the detection area in a first working mode under the condition that the detected object passes through the radiation inspection channel under the driving action of the control device, and controls the radiation device to emit scanning beams to the detection area in a second working mode under the condition that the detected object passes through the radiation inspection channel under the dragging action of the dragging device. Thus, the quality of the image to be formed can be improved, the height dimension of the whole radiation inspection system can be reduced, and dual-mode scanning can be realized.

Description

Radiation inspection system

Technical Field

The invention relates to the field of radiation inspection, in particular to a radiation inspection system.

Background

The inspection system for small and medium-sized passenger vehicles is divided into a dragging scanning mode and a driving scanning mode. In the dragging scanning mode, when the detected vehicle reaches a specific position, a driver and passengers need to get off the vehicle, then the detected vehicle is conveyed to an exit side from an entrance side of a scanning passage by a conveying device, and when the vehicle passes through a scanning area and is conveyed to the specific position, a control system controls a radiation source to emit rays to scan the vehicle. In the drive-through scan mode, the vehicle is driven by the driver through the scan lane.

At present, whether in a dragging scanning mode or a driving scanning mode, a radiation source is basically arranged above a scanning passage, and the vehicle is scanned and imaged by rays from top to bottom so as to obtain a better scanning image visual effect. When the field angle of the radiation source is fixed and the vehicle is overhead, when the vehicle to be inspected is high or wide, in order to be able to scan the whole vehicle completely, the distance between the radiation source and the object to be inspected needs to be increased, that is, the placing height of the radiation source is increased, so that the overall height size of the inspection system is increased, and the index of the scanned image of the vehicle is reduced.

In addition, in the dragging scanning mode, if a single-segment dragging system is adopted, when a vehicle is scanned and imaged, a conveying part at the bottom of the vehicle in an acquired scanning image is overlapped with the vehicle part, so that detection is affected. Therefore, a segmented dragging system is mostly adopted at present to solve the problem that the conveying system blocks rays. But this requires solving the transition problem of the inspected vehicle between the various segments of the towing system, as well as the speed synchronization problem. As shown in fig. 1, taking a two-stage dragging system as an example, according to the vehicle advancing direction, the main beam plane is used as a boundary, the upstream side is a first stage conveyor 1, the downstream side is a second stage conveyor 2, and the middle section between the first stage conveyor 1 and the second stage conveyor 2 is a gap. The first conveyor 1 is generally of a chain plate type, is positioned at the upstream side and is horizontally connected with the middle section; the second conveyor section 2 is of a chain plate type and is positioned at the downstream side and horizontally connected with the middle section, the radiation source 3 is positioned above the middle section, and the radiation emitted by the radiation source can pass through the gap between the first conveyor section 1 and the second conveyor section 2 and is received by the detector. Therefore, the influence caused by the conveying part can be avoided by adopting the multi-section dragging system, but the structure of the whole conveying part is complex, and the accurate and consistent conveying speed of adjacent conveying sections needs to be ensured.

Further, in order to adapt to different application occasions, flexible switching of the scanning mode is required, namely, the vehicle inspection system should provide a dragging scanning mode and a driving scanning mode. The existing vehicle inspection system needs to separately arrange a detection channel for a vehicle which passes through scanning, and additionally occupies space.

Accordingly, there is a need for a new vehicle inspection system that addresses at least one of the problems discussed above.

Disclosure of Invention

The main object of the present invention is to provide a radiation inspection system, particularly for vehicle inspection, which can flexibly switch between two scanning modes for vehicle dragging and vehicle driving while improving the quality of the image to be formed and reducing the height dimension of the whole radiation inspection system.

According to one aspect of the present invention, there is provided a radiation inspection system for radiation inspection of a detected object traveling along a direction of travel defined by a radiation inspection tunnel, the system comprising: the radiation device is arranged at the bottom of the radiation inspection channel and is used for emitting scanning ray beams to the detection area; one or more detectors disposed at the top and/or sides of the radiation inspection tunnel for receiving the imaging beams transmitted or scattered from the inspected object in the inspection region; the dragging device is arranged on one side or two sides of the width direction perpendicular to the advancing direction in the radiation inspection channel, and the upper surface of the dragging device is basically level with the upper surface of the bottom of the radiation inspection channel and is used for dragging the detected object to advance along the advancing direction; and the control device controls the radiation device to emit the scanning ray beams to the detection area in a first working mode under the condition that the detected object passes through the radiation inspection channel under the driving action of the control device, and controls the radiation device to emit the scanning ray beams to the detection area in a second working mode under the condition that the detected object passes through the radiation inspection channel under the dragging action of the dragging device.

Preferably, the dragging means comprises: and the upper surface of the closed-loop conveying mechanism is basically level with the upper surface of the bottom of the radiation inspection channel, and the conveying direction of the upper surface of the closed-loop conveying mechanism is basically consistent with the traveling direction.

Preferably, at least one pushing roller is arranged on the closed-loop conveying mechanism, and the pushing roller pushes the detected object to travel along the traveling direction under the driving of the closed-loop conveying mechanism.

Preferably, the closed loop transfer mechanism may comprise: a driving device for providing a driving force; and the pushing roller is arranged on the closed-loop conveying chain and used for driving the pushing roller to move along the conveying direction under the driving action of the driving device, wherein when the pushing roller moves to the upper surface of the closed-loop conveying chain, the pushing roller is higher than the radiation inspection channel.

Preferably, the radiation inspection system may further include: and the turnover plate is movably arranged between the initial position at the upstream side of the closed-loop conveying mechanism and the radiation inspection channel, and after the detected object moves onto the closed-loop conveying mechanism along the turnover plate, the pushing roller pushes up the turnover plate under the driving of the closed-loop conveying mechanism and moves to the upper surface of the closed-loop conveying mechanism.

Preferably, the radiation inspection system may further include: one or more sensors respectively arranged at the starting position at the upstream side and/or the ending position at the downstream side of the closed-loop conveying mechanism and used for detecting the time information when the detected object passes through the starting position and/or the ending position.

Preferably, the radiation inspection system may further include: and the limiting device is arranged between the end position of the downstream side of the closed-loop conveying mechanism and the radiation inspection channel and used for limiting the detected object at a fixed position when the closed-loop conveying mechanism finishes dragging the detected object.

Preferably, the radiation device may include: a scanning device for emitting a beam of scanning radiation to the detection area; and the attenuation device has a plurality of working modes, and the attenuation device attenuates the intensity of different parts of the scanning ray beams emitted by the scanning device under different working modes.

Preferably, the detected object comprises a part to be detected and a detection avoiding part, in the first working mode, the attenuation device attenuates the intensity of the scanning beam emitted by the scanning device and corresponding to the detection avoiding part in the process that the detection avoiding part of the detected object passes through the detection area, so that the absorption dose rate of the detection avoiding part is lower than a preset threshold value, and in the second working mode, the attenuation device does not attenuate the intensity of any scanning beam emitted by the scanning device.

Preferably, the attenuation device comprises a plurality of attenuation units, different attenuation units are used for attenuating the intensities of the scanning beams of different parts emitted by the scanning device, and the control device determines the attenuation units which participate in the work in the attenuation device when the leading edge of the detection avoiding part of the detected object reaches the detection area according to the area distribution information of the detection avoiding part.

Preferably, the radiation inspection system may further include: the information acquisition device is arranged in the radiation inspection channel at a preset distance from the upstream of the detection area and used for acquiring relative position information among a plurality of characteristic parts of the detected object, the plurality of characteristic parts at least comprise the front edge and the rear edge of the detection evasion part, and the control device determines the area distribution information of the detection evasion part according to the relative position information among the plurality of characteristic parts.

In summary, the radiation inspection system of the present invention employs a bottom-up scanning mode to scan and image an object to be inspected (such as a vehicle) by disposing the radiation source at the bottom of the radiation inspection channel. The distance between the radiation source and the detected object can be reduced, the quality of the formed image is improved, and when the detected object is higher or lower, the position of the radiation source does not need to be adjusted, so that the height size of the whole radiation inspection system can be reduced. A dragging device may be provided at one or both sides within the radiation inspection tunnel. Dual mode scanning can be achieved without increasing the width of the radiation inspection channel.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in greater detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout.

Fig. 1 is a schematic view showing a structure of a conventional segment type dragging apparatus.

Fig. 2 is a schematic block diagram showing the structure of a radiation inspection system according to an embodiment of the present invention.

Fig. 3A and 3B are schematic structural diagrams illustrating a dragging device according to an embodiment of the present invention.

Fig. 4 is a schematic structural diagram showing a radiation device according to an embodiment of the present invention.

Fig. 5A to 5C are schematic views showing the attenuating device of an embodiment of the present invention in different operation modes.

Fig. 6 and 7 are schematic diagrams showing the structure of a single attenuation unit.

Fig. 8A-8D are schematic diagrams illustrating an attenuation apparatus according to another embodiment of the present invention in different modes of operation.

Fig. 9A and 9B are schematic diagrams showing the distribution of characteristic portions on a small-sized vehicle.

Fig. 10 is a schematic diagram illustrating a radiation inspection system in a drag scan mode according to an embodiment of the present invention.

Fig. 10A is an enlarged schematic view of the portion of the dragging device in fig. 10.

Fig. 11 is a schematic structural diagram showing a radiation inspection system in a drive-through scanning mode according to an embodiment of the present invention.

Fig. 11A is an enlarged schematic view of the portion of the dragging device in fig. 11.

FIG. 12 is a side schematic view illustrating a radiation inspection system under an embodiment of the present invention.

FIG. 13 is a schematic top view of a radiation inspection system illustrating one embodiment of the present invention.

Fig. 14 is a schematic structural diagram of a radiation inspection system in a drag scan mode according to another embodiment of the present invention.

Fig. 15 is a schematic view showing a configuration of a radiation inspection system in a drive-through scanning mode in accordance with another embodiment of the present invention.

FIG. 16 is a side schematic view of a radiation inspection system illustrating another embodiment of the present invention.

FIG. 17 is a top schematic view of a radiation inspection system illustrating another embodiment of the present invention.

Detailed Description

Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

As described in the background section, in the current small and medium-sized vehicle inspection systems, radiation sources are almost adopted to be placed at the top of a scanning channel, and the passing vehicles are subjected to transmission imaging by rays from top to bottom.

In addition, if a single-segment type dragging system is adopted, the conveying part can cause the shielding of the scanned image of the inspected vehicle, the transmission image of the key part of the vehicle is overlapped with the dragging device, and the imaging effect is greatly influenced, so that at present, all manufacturers basically adopt a segmented type dragging system, the problem that the conveying system shields rays is solved, but the transition problem of the inspected vehicle among all the segments of dragging systems and the speed synchronization problem need to be solved. Further, in order to adapt to different application occasions, the driver needs to be capable of flexibly switching between the driving passing scanning mode and the dragging scanning mode.

In view of the above, the present invention provides a new radiation inspection system. The radiation inspection system of the invention arranges the radiation source at the bottom of the radiation inspection channel and adopts a bottom-up scanning mode to scan and image the detected object (such as a vehicle). Therefore, the distance between the radiation source and the detected object can be reduced, the quality of the formed image is improved, and when the detected object is higher or lower, the position of the radiation source does not need to be adjusted, so that the height size of the whole radiation inspection system can be reduced. The radiation source may preferably be a radiation source with a large opening angle, so as to ensure that the beam radiated by the radiation source can cover the whole scanning channel in width.

In addition, the radiation inspection system of the invention is also provided with a dragging device at one side or two sides of the radiation inspection channel, the dragging device is arranged below the bottom horizontal plane of the radiation inspection channel, and the middle part is a normal radiation detection channel. The dragging device arranged on one side or two sides can be a single-section dragging system, can also be a multi-section dragging system, and is preferably a single-section dragging system. Therefore, the structure of the dragging device can be simplified and the cost is reduced while the dragging device is prevented from influencing the scanning. And, flexible switching between the drag scan mode and the drive-through scan mode can be achieved without increasing the width of the radiation inspection tunnel.

Furthermore, the invention is additionally provided with an attenuation device which can attenuate the intensity of different parts of light emitted by the radiation source, so that the radiation device consisting of the radiation source and the attenuation device has multiple working modes. Thus, when the radiation inspection system of the invention is flexibly switched between the dragging type scanning mode and the active passing type scanning mode, the radiation device can be controlled to emit scanning ray beams in different working modes according to the selected scanning mode.

Referring to fig. 2, a radiation inspection system 200 includes a radiation device 210, one or more detectors 220, a dragging device 230, and a control device 240.

The radiation device 210 and the detector 220 form a radiation imaging device, wherein the radiation imaging device formed by the radiation device 210 and the detector 220 can be a transmission radiation imaging device or a scattering radiation imaging device, such as a backscatter radiation imaging device. The specific structure of the radiation device 210 and the detector 220 will be described below, and will not be described in detail here.

The radiation device 210 is arranged at the bottom of the radiation examination tunnel for emitting a scanning radiation beam towards the examination area. One or more detectors 220 are disposed at the top and/or sides of the radiation inspection tunnel for receiving imaging radiation beams transmitted or scattered from the inspected object in the inspection area. Preferably, the radiation device 210 may be disposed below a bottom horizontal plane of the radiation inspection channel, and a gap with a certain width may be formed in the radiation inspection channel directly above the radiation device 210, so that the scanning beam emitted by the radiation device 210 can exit through the gap. The detection area may refer to a propagation area of the scanning beam within the radiation inspection channel, and in a case where a propagation direction of the scanning beam is perpendicular to a traveling direction defined by the radiation inspection channel, the detection area is a surface area perpendicular to the traveling direction defined by the radiation inspection channel.

The dragging device 230 is arranged on one side or two sides of the width direction perpendicular to the advancing direction in the radiation inspection channel, and the upper surface of the dragging device is basically flush with the upper surface of the bottom of the radiation inspection channel and is used for dragging the detected object to advance along the advancing direction. Therefore, the dragging device 230 may be a single-side dragging device or a double-side dragging device, and the dragging device 230 may drag one or both sides of the detected object to drive the whole detected object to move along the moving direction.

The control device 240 may control the radiation device 210 to emit the scanning beam to the detection area in a first operation mode in a case where the detected object passes through the radiation inspection passage under its own driving action, and may control the radiation device 210 to emit the scanning beam to the detection area in a second operation mode in a case where the detected object passes through the radiation inspection passage under the dragging action of the dragging device 230. The first working mode and the second working mode respectively correspond to the specific mode that the detected object passes through the radiation inspection channel.

Taking the detected object as an example, when a driver drives a vehicle to pass through a radiation inspection channel, the detection of avoiding the personnel distribution area on the vehicle is needed, and the personnel on the vehicle are prevented from being subjected to higher radiation dose. When a driver and passengers get off the vehicle and the vehicle is dragged by the dragging device to pass through the radiation inspection passage, the whole vehicle can be normally detected. Therefore, in the first working mode, the radiation device can carry out evasive detection on the personnel distribution area on the vehicle and carry out normal detection on other areas, and in the second working mode, the radiation device can carry out normal detection on the whole vehicle. The avoidance detection may be attenuation of a scanning beam corresponding to a person distribution area on the vehicle. Thus, when the radiation inspection system of the present invention is applied to vehicle inspection, it is possible to flexibly switch between the pull-type scanning mode and the active pass-through scanning mode.

The basic structure and operation of the radiation inspection system 200 of the present invention is now briefly described with reference to fig. 2. The structure of the various components that make up radiation inspection system 200 are described further below.

First, dragging device

In the present invention, the dragging device may be a single-segment dragging device, or may be a multi-segment dragging device, preferably a single-segment dragging device, wherein the single-segment dragging device is a whole segment from the entrance area, the scanning area, and the exit area, and the middle of the single-segment dragging device is not disconnected. Moreover, the dragging device can be arranged on one side of the width direction in the radiation inspection channel for unilateral dragging, and also can be arranged on two sides of the width direction in the radiation inspection channel for bilateral dragging. Taking the detected object as a vehicle as an example, the dragging device can be a single-side dragging device, and a single-side wheel of the dragging vehicle moves along the travel direction defined by the radiation inspection channel; the dragging device can also be a bilateral dragging device, dragging the double-side wheels of the vehicle to travel along the travel direction defined by the radiation inspection passage. The dragging device can move the vehicle by pushing a front wheel drive of the vehicle, can also move the vehicle by pushing a rear wheel drive of the vehicle, and preferably can push the front wheel of the vehicle.

The dragging device can move in a single direction or in two directions along the travel direction defined by the radiation inspection channel. In the present invention, the dragging device may preferably employ a closed-loop transfer mechanism that can be cyclically rotated in one direction to push the detected object. For example, the closed-loop conveying mechanism can be a plurality of devices which can do circular reciprocating motion, such as an endless chain, a chain plate and the like. When the chain transmission is adopted, the structure can be a single-chain structure or a double-chain structure. The transport direction of the upper surface of the closed loop transport mechanism should be set to coincide or substantially coincide with the direction of travel defined by the radiation inspection tunnel.

The body structure of the closed-loop transport mechanism may be mounted below the bottom level of the radiation inspection tunnel such that the upper surface of the closed-loop transport mechanism is substantially level with the bottom upper surface of the radiation inspection tunnel. When the radiation inspection channel is set to be a sloping platform structure with a certain height away from the ground, the main structure of the closed-loop transmission mechanism can be arranged in the sloping platform.

Fig. 3A is a side view showing the case where the single-chain actuator is used as the actuator, and fig. 3B is a plan view.

As shown in fig. 3A and 3B, the dragging device may include a driving device 1133 and a closed-loop conveyor chain 1134.

The driving device 1133 is used for providing a driving force for the movement of the closed-loop transmission chain 1134, and may be a motor and a speed reducer, or may be a hydraulic motor and a speed reducer, and other driving devices.

The closed-loop transmission chain 1134 can perform a circular reciprocating motion under the driving action of the driving device 1133. The chain of the closed-loop conveyor 1134 may be lower than the bottom surface of the radiation inspection channel, and one or more pushing rollers may be disposed on the chain of the closed-loop conveyor 1134, and the pushing rollers may move along with the transmission chain, and may be in direct contact with a dragging portion of the detected object (e.g., a wheel of a vehicle) to act as pushing members to push the detected object to travel along the travel direction defined by the radiation inspection channel.

In the present invention, the radiation inspection passage directly above the closed-loop conveyor 1134 may be referred to as a conveying track 1130, and a gap with a certain width may be provided on the conveying track 1130 in the traveling direction, so that the push roller can move above the conveying track 1130 through the gap and drive the detected object to travel along the conveying track 1130 along with the rotation of the closed-loop conveyor 1134.

In consideration of improving the conveying efficiency and saving energy, a plurality of pushing rollers may be disposed on the chain of the closed-loop conveying chain 1134, so that the closed-loop conveying chain 1134 may push a plurality of detected objects to move along the conveying track 1130 by using the plurality of pushing rollers during the rotation process. As an alternative embodiment of the invention, as shown in fig. 3A, a first push roller 11311 and a second push roller 11312 may be disposed at two symmetrical positions on the closed-loop conveyor chain 1134. Wherein when the first push roller 11311 or the second push roller 11312 moves to the upper surface of the closed loop conveyor chain, the push roller is higher than the upper surface of the bottom of the radiation inspection channel.

As shown in fig. 3A, a flap 1140 may also be movably disposed between the home position on the upstream side of the closed loop conveyor and the radiation inspection passageway 1091. After the dragging part of the detected object moves onto the conveying track 1130 along the turning plate 1140, the corresponding push roller (the first push roller 11311 or the second push roller 11312) can push up the turning plate 1140 and move onto the conveying track 1130 along with the rotation of the closed-loop conveyor chain 1134. Thereafter, the object to be detected can travel along the conveying rail 1130 under the pushing action of the pushing rollers.

Further, one or more sensors may be provided at the start position on the upstream side and/or the end position on the downstream side of the closed-loop conveying mechanism, respectively, for detecting information on the timing at which the detected object passes the start position and/or the end position. For example, the first position sensor 11361 may be provided on the upstream side of the flap 1140, and the third position sensor 11363 may be provided on the downstream side of the flap 1140. A first position sensor 11361 may be used to detect whether the first push roller 11311 or the second push roller 11312 reaches a suitable position below the flap; the third position sensor 11363 may be used to detect whether the trailing portion of the inspected object passes over the flipper 1140 to the delivery track 1130. After the dragging part of the detected object passes through the turning plate 1140, the driving device 1133 may be activated to drive the first pushing roller 11311 or the second pushing roller 11312 to push up the turning plate 1140 and move onto the conveying track 1130, so that the pushing roller pushes the dragging part of the detected object to drive the detected object to travel along the conveying track 1130. As shown, a fourth position sensor 11364 may also be provided near the upstream side of the end position of the closed loop conveyor chain 1134, and a second position sensor 11362 may be provided near the downstream side of the end position. When the detected object passes the fourth position sensor 11364, indicating that the dragging of the detected object is completed soon, the driving device 1133 may be controlled to decelerate, and when the pushing roller pushing the detected object is detected to reach the second position sensor 11362, indicating that the dragging of the detected object is completed, the driving device 1133 may be controlled to stop working.

Further, as shown in fig. 3A, a limiting device 1150 may be further disposed between the end position of the downstream side of the closed-loop conveying mechanism and the radiation inspection channel, for limiting the detected object to a fixed position at the downstream side of the end position when the closed-loop conveying mechanism finishes dragging the detected object, for example, taking the detected object as a vehicle, the pushing roller pushes the wheel to the position, so that the vehicle will not roll away without braking. The closed loop conveyor mechanism may also include a tensioning device 1135 that may be used to adjust the tightness of the closed loop conveyor chain 1134.

Further, as shown in fig. 3B, a position-limiting safety rod 112 may be disposed on both sides of the entire radiation inspection passage for ensuring that the detected object travels along the middle position of the radiation inspection passage as much as possible. An anti-derailing side stop 1138 may be disposed on both sides of the conveying track 1130, for limiting a dragging portion (e.g., a wheel of a vehicle) of the detected object from being separated from the conveying track 1130 when the detected object is dragged along the conveying track by the dragging device. A stopper 1139 may be disposed on the conveying track, and the stopper may be controlled to move up and down by a control command, so as to block or release the passing detected object. For example, in the dragging mode, when the vehicle is ready to enter the conveying track 1130, the stopper 1139 will be raised to block the wheel, so that the initial position of the wheel parking does not exceed the stopper, and after the system is ready, the dragging device can be activated to push the wheel.

Radiation device

The radiation device of the invention is used for emitting a scanning ray bundle to a detection area. Different from the existing radiation device, the radiation device of the invention can emit scanning ray beams according to the working mode corresponding to the scanning mode according to the specific scanning mode (dragging scanning or driving through scanning) of the detected object (vehicle).

The following further explains the specific structure and operation principle of the radiation device.

The radiation device of the present invention may comprise a scanning device and an attenuation device. The scanning device is used for emitting scanning ray beams to the detection area. The detection area is an area where the object to be detected is subjected to radiation inspection, and may be an area where a scanning beam emitted by the scanning device propagates in space. When the scanning device is disposed at the bottom of the radiation inspection passage for scanning an object to be inspected (such as a vehicle) traveling along a traveling direction defined by the radiation inspection passage, the scanning beam emitted by the scanning device is preferably perpendicular to the traveling direction of the object to be inspected, and the detection area is a surface area perpendicular to the traveling direction of the object to be inspected.

The scanning device may be an existing conventionally constructed scanning device. For example, the scanning device may comprise a radiation source and a collimator. The radiation source can adopt an X-ray tube of 160 kV-450 kV, and a shielding device made of lead or tungsten material can be used for shielding the useless ray beams which are not emitted to the detection area. Wherein the shielding device can be designed in a labyrinth shape to improve the shielding effect. The shielding device can be provided with a window, and the ray bundle emitted by the radiation source can enter the collimator through the window.

The collimator can be arranged in the radiation direction of the radiation source, a beam slit is arranged on the collimator, and the collimator can restrict the field angle of the X-ray beam radiated by the radiation source in the height direction (perpendicular to the scanning direction) and the width of the X-ray beam radiated by the radiation source in the scanning direction (the movement direction of the detected object) through the beam slit. The ray bundle emitted by the radiation source forms a scanning ray bundle emitted to the detection area through the beam action of the beam slit.

The attenuator has a plurality of modes of operation. The attenuation device can attenuate the intensity of different parts of scanning beams emitted by the scanning device in different working modes, so that the absorption dose rate of the attenuated scanning beams incident to corresponding parts on a detected object in the detection area is lower than a preset threshold value. Wherein the corresponding portion is preferably a detection avoiding portion on the detected object. Taking the detected object as an example of a vehicle, the corresponding part may be a region of the vehicle, such as a main driver, a passenger driver, a rear seat, and the like, where a person is present. The preset threshold may be a safety value set according to an actual situation, and the absorption dose rate is used to measure an energy absorption situation of the object after being irradiated, and may be an absorption dose in a unit time when the object is irradiated. For purposes of the present invention, an absorbed dose rate can also be characterized as a single absorbed dose, which refers to the amount of radiation energy absorbed by a unit mass of matter after exposure to radiation, and a single absorbed dose, which is the amount of radiation energy absorbed by a unit mass of matter during a single exposure to radiation.

When the radiation inspection is performed on the detected object, the single absorbed dose of the detection avoiding portion of the detected object is positively correlated with the radiation time of the detection avoiding portion through the radiation inspection and the radiation intensity of the radiation source. The intensity of a scanning ray beam emitted by a radiation source and corresponding to the detection avoiding part is attenuated to change the radiation intensity of the radiation source, so that the radiation intensity received by the detection avoiding part is reduced, and the single absorption dose of the detection avoiding part is lower than a preset threshold. The specific attenuation degree of the scanning ray bundle can be determined according to various parameters such as the setting of a preset threshold, the actual traveling speed of the detected object, the radiation parameters of the radiation source, the distance between the radiation source and the detected object, and the like, and the details are not repeated here.

Therefore, the working mode of the attenuation device can be controlled according to the specific detection mode of the detected object, so as to form the working modes of the radiation device under different scanning modes. Taking the detected object as an example, when a driver drives the vehicle to detect, the radiation device may operate in a first operating mode, and in the first operating mode, in a process that the detection evasion portion of the vehicle passes through the detection region, the attenuation device may control the operating mode thereof, so that only the target scanning beam corresponding to the detection evasion portion among the scanning beams emitted by the scanning device is attenuated in the operating mode. Therefore, under the condition of ensuring that the detection evasion part is not radiated by high intensity, the normal detection of the non-detection evasion part on the detected object is not influenced. When the person gets off the vehicle and the dragging device drags the vehicle for detection, the radiation device can work in a second working mode, and the attenuation device can not attenuate the intensity of any scanning ray beam emitted by the scanning device in the second working mode.

It should be noted that, when the detected object has a plurality of detection avoiding portions, and the plurality of detection avoiding portions pass through the detection area and correspond to different portions of the scanning beam, the attenuation device may control the operation mode of the plurality of detection avoiding portions of the detected object in real time in the process of passing through the detection area one by one, so as to realize the attenuation of the scanning beam corresponding to the detection avoiding portion passing through the detection area. Taking an example that the detected object is a left-driving vehicle with 5 seats, a driver is arranged at a driving position on the vehicle, and a passenger is arranged at a middle seat in the rear row, when the cab passes through the detection area, the working mode of the attenuation device can be controlled, so that the attenuation device attenuates the scanning ray beams corresponding to the left cab, when the rear seat passes through the detection area, the working mode of the attenuation device can be switched, and the attenuation device is controlled to attenuate the scanning ray beams corresponding to the middle seat in the rear row.

The basic structure of the radiation device of the present invention and the basic process of performing radiation inspection on an object to be inspected by using the radiation device of the present invention are briefly described so far. From the above description, it can be seen that the present invention mainly achieves attenuation of different parts of the scanning beam emitted by the scanning device by the attenuation device, and the working principle and the specific structure of the attenuation device are further explained below.

The intensity of the radiation decreases after passing through the material, a phenomenon known as attenuation. Different metal materials (such as aluminum, iron, copper, lead, alloys, etc.) have different attenuation coefficients for radiation. The attenuation device of the invention can be made of one or more materials with strong ray attenuation capability, such as aluminum, iron, copper, lead, alloy and the like.

The attenuation device can realize the attenuation of the scanning ray beam by blocking the scanning ray beam. The attenuation device can have a plurality of working modes, and the attenuation device can attenuate the intensity of different parts of scanning ray beams emitted by the scanning device in the radiation imaging device under different working modes. In other words, the attenuation device can shield different parts of the scanning ray beams emitted by the scanning device so as to realize the attenuation of the different parts of the scanning ray beams.

Fig. 4 is a schematic structural view showing a radiation device according to an embodiment of the present invention.

In this embodiment, the scanning device may comprise a radiation source 101, a switching device 102 and a collimator 104.

The radiation source 101 is for emitting a radiation beam. A shielding device (not shown) may be arranged near the radiation source 101, the shielding device may be designed in a labyrinth shape, and the shielding device may surround the radiation source 101, and the shielding device may leave a window corresponding to a portion of the radiation emitted by the radiation source 101. The radiation beam emitted by the radiation source 101 may exit through the window.

The switching device 102 may be made of one or more radiation attenuating materials such as lead or tungsten. The switching means 102 may be used to control the shielding of the radiation beam emitted by the radiation source 101 towards the detection area. When the switch device 102 is closed, the radiation can be completely blocked from transmitting to the detection area, and when the switch device 102 is opened, the radiation can not be blocked from transmitting to the detection area. The switching device 102 may control the shielding state of the radiation beam emitted by the radiation source 101 by shielding or not shielding a window reserved in the shielding device.

The collimator 104 is provided with a beam slit, and the radiation beam emitted by the radiation source 101 can form a scanning radiation beam emitted to the detection area after passing through the beam slit.

The attenuating device 130 may attenuate the scanning beam emitted from the beam slits at different positions to form a plurality of operating modes. For example, the attenuation device can realize the attenuation of the scanning ray beams emitted from the corresponding parts by blocking the beam stream slits at different parts. When attenuating the intensity of the corresponding part of the scanning beam, the attenuation device 120 may attenuate completely or partially, as long as the absorption dose rate of the detected object at the position corresponding to the scanning beam after attenuation is lower than a preset threshold.

In theory, it is possible that all the scanning beams exiting from the beam slit of the collimator 104 correspond to the detection evasion portion of the detected object. Therefore, preferably, the attenuating device 130 should be configured to attenuate all or most of the scanning beam exiting from the beam slit.

As an alternative embodiment of the present invention, the attenuating device 130 may be composed of a plurality of attenuating units. The plurality of attenuation units can respectively correspond to different parts of the beam seams, the plurality of attenuation units can be of mutually independent structures, and each attenuation unit can realize the attenuation of the scanning beam emitted from the beam seam at the corresponding part by shielding the beam seam at the corresponding part. Therefore, different working modes can be formed by controlling different attenuation units to participate in working.

As shown in fig. 5A, the attenuation apparatus may be composed of 11 attenuation cells S1-S11, and the 11 attenuation cells may be closely arranged, each attenuation cell corresponding to a portion of the beam slit 1151 of the collimator 104. The beam slit 1151 of the corresponding portion can be shielded by moving the attenuation unit, so that the intensity of the scanning beam emitted from the beam slit of the corresponding portion can be attenuated. As shown in fig. 5B, the beam slit 1151 of the corresponding portion can be blocked by the movable attenuation units S7 and S8, and the intensity of the scanning beam emitted from the corresponding portion can be attenuated. As shown in fig. 5C, the other beam slit 1151 may be blocked by moving the attenuation units S3 to S6, so that the scanning beam emitted from the other beam slit is attenuated.

As mentioned above, the attenuating means should preferably be arranged to attenuate all or a substantial part of the scanning beam exiting from the beam slit. Therefore, a plurality of attenuation units constituting the attenuation apparatus may preferably correspond to the whole or most of the beam slits 1151. In addition, a plurality of attenuation units forming the attenuation device may also correspond to only a part of the beam slit 1151, and at this time, the plurality of attenuation units may be integrally translated along the direction of the beam slit 1151, so that the attenuation device may attenuate the whole or most of the scanning beam emitted from the beam slit.

When the attenuator is composed of a plurality of attenuation units, the length of the beam slit 1151 corresponding to a single attenuation unit can be regarded as the control accuracy of the attenuator on the scanning beam, and the shorter the length of the beam slit 1151 corresponding to a single attenuation unit is, the smaller the minimum controllable part of the scanning beam is, and the higher the control accuracy of the attenuator is. In practical applications, the number of the attenuation units constituting the attenuation apparatus and the length of the beam slit 1151 corresponding to each attenuation unit may be set according to actual requirements, and are not described herein again.

Fig. 6 is a schematic diagram showing one structure that a single attenuation cell may have. As shown in fig. 6, the attenuation unit may include an attenuation block 1212 and a driving device 1211.

The attenuation block 1212 may be made of one or more materials with strong ray attenuation capability, such as aluminum, iron, copper, lead, alloy, etc. The driving device 1211 is configured to drive the attenuation block 1212 to shield the beam slit 1151 at the corresponding portion, so as to attenuate the intensity of the scanning beam exiting from the beam slit 1151 at the corresponding portion, and may further drive the attenuation block 1212 to be away from the beam slit 1151 at the corresponding portion, so that the scanning beam exiting from the beam slit 1151 at the corresponding portion can normally enter the detection region. The driving device 1211 may be a power mechanism having a telescopic structure, a push-pull mechanism, or the like. For example, the driving device 1211 may be a high-speed electromagnet.

The size of the attenuation block 1212 may be set as practical. As shown in fig. 6, generally, the width w of the attenuation block 1212 perpendicular to the propagation direction of the scanning beam emitted from the beam slit 1151 should be set to be greater than or equal to the slit width of the beam slit 1151 corresponding thereto, so that the attenuation block 1212 can block the beam slit 1151 at the corresponding portion. For example, the width w may be set larger than the maximum slit width of the beam slit 1151.

The thickness of the attenuation block 1212 in the propagation direction of the scanning beam emitted from the beam slit 1151 should be set so that the intensity of the scanning beam emitted from the beam slit 1151 at the corresponding position is attenuated by the attenuation block 1212, and then the absorption dose rate incident on the corresponding position on the detected object in the detection area is lower than a preset threshold.

As is well known to those skilled in the art, when an object at a distance R from a target point is irradiated by a radiation beam (e.g., X-rays), the absorbed dose can be approximated by the following equation:

D＝f·X₀·I·t·(R₀/R)²

wherein f is the absorbed dose conversion coefficient (ge/n), X₀Is off target as R₀The output of the radiation (Lon/milliampere) is, I is the tube current (milliampere), t is the irradiation time (minute), R₀To find out the narrow beam output X on the graph₀And the distance (centimeter) from the target point, and R is the distance (centimeter) from the actual irradiated point to the target point.

From the above formula, if the single absorbed dose of the radiation beam received by the passenger or the special position on the vehicle is to be reduced under the condition of a certain radiation source parameter, one method is to increase the speed of the scanned vehicle or the passenger to pass through so as to reduce the irradiation time of the radiation, and the other method is to add metal filtering between the scanned object and the radiation source, on one hand, the low-energy radiation which is useless for the quality of the scanned detection image is filtered, on the other hand, the intensity of the radiation is attenuated, and the single absorbed dose irradiating the passenger area of the vehicle is reduced to a very low level. The detection precision of the normal detection part of the vehicle is influenced to a certain extent by improving the passing speed of the scanned vehicle or the scanned person, so that the single-time absorbed dose of the person on the vehicle or a special position on the vehicle is reduced by adopting a mode of attenuating rays.

The intensity of the radiation after passing through the substance is reduced, which is called attenuation, and different metal materials (such as aluminum, iron, copper, lead, alloys, etc.) have different attenuation coefficients for the X-ray. The physical quantity describing the attenuation properties of the rays is called the attenuation rate, and the calculation formula is as follows: j. the design is a square_d＝J₀·e^-ud. In the formula, J_dIntensity after passage of the radiation through the material, J₀Is the intensity of the radiation without passing through the material, and u is the attenuation coefficient of the radiation, representing the radiationThe degree of attenuation of the intensity after penetration of a unit length of material, d is the thickness of the material.

In a radiation inspection system, the single absorption dose of the detected object is basically from useful ray beams, and according to the requirement of specific single absorption dose limit values, the thickness of the attenuation block can be calculated after the material of the attenuation block and the following technical parameters of the detection system are determined. The technical parameters of the aspects are as follows: radiation dose rate at 1 meter from the source (μ Sv ∙ m)²∙h^-1) The device comprises a detection avoiding part, a radiation source, a distance (m) between the detection avoiding part and the radiation source, a beam width of a scanning beam corresponding to the detection avoiding part and incident on the detection avoiding part, and a relative moving speed (m/s) between a detected object and the radiation source.

As shown in fig. 7, the length of the attenuation block 1212 along the beam slit direction may be determined based on the distance between the attenuation block 1212 and the radiation source 101 and the radiation angle β of the scanning radiation beam to which the attenuation block 1212 corresponds. The radiation angle β can be regarded as the control accuracy of the attenuation device, and the smaller the radiation angle β, the higher the control accuracy of the attenuation device 130.

Fig. 8A to 8D are schematic views showing the structure of an attenuating device according to another embodiment of the present invention. Fig. 8A is a front view, fig. 8B is a schematic top view when not blocked by the damping block, and fig. 8C is a schematic top view when the damping blocks S6 and S8 are pushed out to participate in the operation.

As shown in fig. 8A, the attenuating device may be composed of 13 attenuating units S1-S13. Wherein each attenuation unit comprises a high-speed push-pull 1051 (preferably a high-speed electromagnet), an attenuation block 1052, a positioning rod 1053 and a push rod 1054. Attenuation block 1052 is mounted on positioning rod 1053. The positioning rod 1053 is connected to the end of the push rod 1054. The push rod 1054 is a moving part of the high-speed push-pull 1051.

Each attenuation unit can independently act under the instruction of the controller, the push rod pushes the attenuation block to rapidly stretch, the ray of the corresponding block is filtered when the attenuation block extends out, and the ray filtering is cancelled when the attenuation block retracts. The high-speed push-pull 1051 action execution time of each damping unit is not more than 20ms (preferably not more than 10 ms). The stroke of the push rod 1054 is not less than 3mm (preferably 20 mm). In the process of carrying out radiation inspection on the detected object such as a vehicle, the control system can selectively send out commands to control the relevant attenuation units to execute actions according to the acquired characteristic information of the detected object in the scanning channel, and the pushed attenuation blocks weaken or shield the ray intensity of the corresponding area so as to limit the single absorption dose of the corresponding area in an extremely low range.

Fig. 8D is a schematic side view, as shown in fig. 8D, where the collimator 104 and the attenuating device 130 may be mounted on a mounting block 1041. The scanning device may further comprise a switching device 102, the switching device 102 being adapted to control the shielding state of the radiation beam emitted by the radiation source 101 towards the detection area. The switching device 102 may be made of a radiation-shielding material having an extremely strong attenuation capability to radiation, such as lead, tungsten, and the like. The switching device 102 can rapidly switch on and off the radiation beam emitted by the radiation source 101 and directed to the detection area by rapidly closing or opening the radiation window. The switch device 102 can completely block the radiation from penetrating to the safety scanning area when being closed, and does not block any useful radiation beam from being emitted to the detection area when being opened.

Third, the detector

The detector and the radiation device constitute a radiation imaging device, preferably a transmission radiation imaging device. Wherein the detector may be arranged at the top and/or at the side of the radiation examination channel.

The detector may be plural, the detection faces of the plural detectors may be perpendicular to the propagation direction of the scanning beam emitted by the scanning device, and the center lines of the detection faces of the plural detectors may be substantially in a plane. The center line mentioned here means a center line in the detection plane which is substantially in the same direction. For example, the detecting surface of the detector is mostly rectangular, the center line of the rectangle may include a center line of an excessively long side and a center line of an excessively short side, after the detecting surfaces of the plurality of detectors are fixed, the center lines of the detecting surfaces of the plurality of detectors may be divided into a center line approximately along the horizontal direction and a center line approximately along the vertical direction, and the center lines of the detecting surfaces of the plurality of detectors are substantially in one plane, which means that the center lines approximately along the same direction (horizontal and/or vertical) are substantially in one plane.

Fourth, information acquisition device

Returning to fig. 2, the radiation inspection system may also optionally include an information acquisition device 250, shown in phantom.

The information acquiring means 250 may be disposed at a predetermined distance upstream from the detection region within the radiation inspection tunnel for acquiring relative position information between a plurality of characteristic portions of the detected object, the plurality of characteristic portions including at least a leading edge and a trailing edge of the detection avoiding portion, and the control means 240 may determine the region distribution information of the detection avoiding portion based on the relative position information between the plurality of characteristic portions.

Specifically, the control device 240 may acquire attribute information of the detected object in advance, which may include, but is not limited to, approximate area distribution information of the detection avoidance portion in the detected object. Taking the detected object as a vehicle as an example, the attribute information may include, but is not limited to, a license plate number, a vehicle type, a number of vehicle seats, a distribution of people on the vehicle, and other information such as a vehicle body color, a vehicle contour, driver identification, a driver face photograph, etc. Thereby, the basic outline and/or the characteristic region distribution information of the detected object can be determined based on the relative position information between the plurality of characteristic portions acquired by the information acquiring means 250. And the attribute information acquired by the information acquisition device includes approximate area distribution information of the detection avoiding portion in the detected object, so that accurate area distribution information of the detection avoiding portion in the detected object can be determined according to the attribute information and the relative position information between the plurality of characteristic portions.

As shown in fig. 9A and 9B, taking a vehicle with a detected object as a seat for 5 persons as an example, the vehicle may be divided into five feature areas, and each feature area includes a plurality of feature portions. Specifically, the first characteristic region includes a vehicle head foremost edge P1, a vehicle head contour inflection point P2. The second characteristic region comprises a lower edge P3 of a front windshield of the vehicle, a left rearview mirror P4 of the vehicle, a right rearview mirror P4 of the vehicle, a left A column P4a of the vehicle, a right A column P4 a' of the vehicle, and an upper edge P5 of the front windshield of the vehicle. The third feature includes the vehicle left B-pillar P6, the vehicle right B-pillar P6', and the vehicle roof P7. The fourth characteristic zone comprises a vehicle left middle pillar P8, a vehicle right middle pillar P8', a rear windshield upper edge P9 and a rear windshield lower edge P10. The fifth characteristic zone comprises a tail section contour inflection point P11 and a tail section final edge P12.

Further, the second characteristic region and the third characteristic region can be further divided according to the seat arrangement of the vehicle. As shown in fig. 8B, the second characteristic region may be divided into a main driving region a12, a passenger driving region a11, and the third characteristic region may be divided into a left-side seat region a22, a middle seat region a20, and a right-side seat region a 21. Also, the leading edge and the trailing edge of each feature region, as well as sub-feature regions within the feature region (e.g., the seating region), may be described by corresponding features. The size information of each seat in the vehicle can be obtained by analyzing a plurality of characteristic parts, and the national design standard 'size in passenger car GBT 13053-2008' can also be referred to.

The attribute information acquired in advance by the control device 240 may be the distribution of persons on the detected vehicle, such as only one person in the main driver seat. The information acquisition device 250 may acquire relative position information between a plurality of characteristic portions of the vehicle shown in fig. 8A and 8B, and may obtain a basic outline of the vehicle and a distribution of each characteristic region from the acquired relative position information between the plurality of characteristic portions of the vehicle. Thus, the area a12 can be determined as the detection avoidance portion corresponding to the main driver seat. The front edge of the region a12 is the feature P4 or P4a, and the rear edge is the feature P6. The size of the area a12 can be determined by reference to the national design standard "passenger car interior size GBT 13053-2008", or by the relative position information among the characteristic parts P4, P4a, P6, and P6'.

In the present invention, the information acquiring device 250 may acquire the relative position information between the plurality of characteristic portions of the detected object by using various methods such as ranging, a correlation sensor, an image analysis technique, and the like. Several possible implementations of the information acquisition device 250 are described below.

1. Distance measurement

In brief, a scanning beam can be emitted to a detected object, distance information of a plurality of positions on the detected object can be determined according to a time difference of receiving a signal returned from the detected object, and shape information of the detected object can be obtained by analyzing the distance information of the plurality of positions. By further analyzing the shape of the detected object, the relative position information between a plurality of representative characteristic parts can be obtained.

In acquiring the relative position information between the plurality of characteristic portions based on the distance measuring principle, the information acquiring device 250 may acquire the relative position information between the plurality of characteristic portions of the detected object by using various distance measuring devices such as a laser distance measuring device and an ultrasonic distance measuring sensor.

Taking the information acquisition device 250 as a laser ranging device for example, the laser ranging device may be disposed above or at the side (left or right) of the radiation inspection channel. The laser ranging device may periodically scan a laser beam toward the radiation inspection tunnel at a predetermined frequency, an exit direction of the laser beam being preferably substantially perpendicular to a traveling direction defined by the radiation inspection tunnel, and a surface along which the laser beam is formed may be referred to as a laser scanning surface. When the laser distance measuring device is arranged above the radiation inspection tunnel, the laser distance measuring device can preferably be arranged directly above the radiation inspection tunnel, in which case the projection of the laser scanning surface onto the horizontal plane should preferably cover the entire radiation inspection tunnel in the width direction. When the laser distance measuring device is arranged at the side of the radiation inspection channel, the projection height of the laser scanning surface on the vertical plane should preferably be larger than the height of the detected object.

The laser ranging device may obtain ranging values corresponding to the laser beams emitted at a plurality of unit angles (minimum resolution angles) according to a predetermined angular resolution for each emission period to obtain a plurality of ranging values. When the detected object does not pass through the laser scanning surface, the obtained multiple distance measurement values are distance information when the detected object does not exist in the radiation inspection channel. When the detected object passes through the laser scanning surface, the plurality of distance measurement values obtained at each period are the distance measurement values of a plurality of positions of the detected object in the width direction in the radiation inspection channel when the detected object passes through the laser scanning surface. The basic contour information of the detected object can be obtained by analyzing the range values in a plurality of periods, and the relative position information between a plurality of characteristic parts and a plurality of characteristic parts in the detected object can be further obtained by analyzing the basic attribute information such as the type of the detected object.

When the information acquiring device 250 employs a laser ranging device and is disposed above the radiation inspection channel, the laser beam emitted by one laser ranging device may not scan the whole detected object considering that the detected object may have a large width. Therefore, the information acquisition device may also employ two or more laser ranging devices.

2. Correlation type sensor

The correlation sensor generally comprises a transmitting part and a receiving part which are separated, wherein the transmitting part and the receiving part can be respectively arranged at two sides of a radiation inspection channel, and the measurement principle is that the transmitting part transmits signals, and the receiving part judges whether the transmitting part and the receiving part are shielded according to whether the signals are received, so as to judge whether a detected object exists between the transmitting part and the receiving part.

Thus, the information acquiring device 250 may employ a plurality of correlation sensors or a correlation sensor array, the transmitting portions and the receiving portions of the plurality of correlation sensors or the correlation sensor array may be respectively disposed at both sides of the radiation inspection channel, and the detection surfaces of the plurality of correlation sensors or the correlation sensor array may be substantially located in the same plane and perpendicular to the traveling direction defined by the radiation inspection channel. When the detected object passes through the detection surfaces of the plurality of correlation sensors or the correlation sensor array, the side structure of the detected object positioned in the detection surface at a certain moment can be determined according to the signal receiving condition of the plurality of receivers at the moment, so that the whole side structure information of the detected object can be obtained when the detected object completely passes through the detection surfaces. By analyzing the side structure information, the relative position information between the plurality of characteristic parts and the plurality of characteristic parts can be further obtained.

In addition, when the information acquisition device 250 employs a plurality of correlation sensors or correlation sensor arrays, the transmitting portions and the receiving portions of the plurality of correlation sensors or correlation sensor arrays may be disposed above and at the bottom of the radiation inspection passage, respectively. The detection faces of the plurality of correlation sensors or the correlation sensor array may lie substantially in the same plane and perpendicular to the direction of travel defined by the radiation inspection channel. When the detected object passes through the detection surfaces of the plurality of correlation sensors or the correlation sensor array, the overlooking structure of the detected object positioned in the detection surface at a certain moment can be determined according to the signal receiving condition of the plurality of receivers at the moment, so that the whole overlooking structure information of the detected object can be obtained when the detected object completely passes through the detection surfaces. By analyzing the overhead view structure information, relative position information between the plurality of features and the plurality of features can be further obtained.

3. Image analysis technique

The information acquiring means 250 may also acquire relative position information between a plurality of characteristic portions of the detected object based on an image analysis technique. In particular, the information acquisition device may employ an image sensor, which may be disposed above and/or to the side of the radiation inspection tunnel. The image sensor is used for imaging the detected object, and the relative position relation among a plurality of characteristic parts and a plurality of characteristic parts of the detected object can be obtained by analyzing the formed image. The image analysis techniques are well known to those skilled in the art and will not be described herein.

So far, the structure of the radiation imaging system of the present invention is explained in detail. The following will further explain the application of the radiation inspection system of the present invention by taking the detected object as a vehicle.

Specific examples of the applications

Example one

10-13, wherein FIG. 10 is a front view illustrating a vehicle undergoing a drag scan using a radiation inspection system constructed in accordance with the present invention; FIG. 10A is an enlarged schematic view of the portion of the dragging device of FIG. 10; FIG. 11 is a front view showing a vehicle being driven through a scan using a radiation inspection system constructed in accordance with the present invention; FIG. 11A is an enlarged schematic view of the portion of the dragging device of FIG. 11; FIG. 12 is a side view; fig. 13 is a plan view.

The rack 100 may be built on a chassis 1001. The rack 100 may include a left upright rack and a right upright rack, perpendicular to the upper surface of the chassis 1001. The lower ends of the left upright post frame and the right upright post frame are respectively connected with the left side and the right side of the chassis 1001, the upper ends of the left upright post frame and the right upright post frame are respectively connected with the left side and the right side of the cross beam frame, and the left upright post frame, the right upright post frame, the cross beam frame and the chassis 1001 form a square channel for a scanned vehicle to pass through.

The front and rear sides of the chassis 1001 may be connected to an upstream side flat table 1092 and a downstream side flat table 1093, respectively, and the upper surface of the chassis 1001 is on the same horizontal plane as the upper surfaces of the upstream and downstream side flat tables. The upstream side flat land 1092 and the downstream side flat land 1093 may be higher than the ground, and the portions of the connection between the upstream side flat land 1092 and the downstream side flat land 1093 and the ground may be provided with an upstream side flat land 1091 and a downstream side flat land 1094, respectively, so that the vehicle can smoothly enter and exit the radiation inspection passage. The upstream side ramp 1091, the upstream side ramp 1092, the chassis 1001 and the rack 100, the downstream side ramp 1093, and the downstream side ramp 1094 constitute the entire radiation inspection passage.

The chassis 1001 is a bearing foundation of the whole set of equipment, the horizontal flatness of the chassis 1001 can be flexibly adjusted, and a radiation device and a dragging device can be installed in the chassis 1001. Wherein, a gap with a certain width is reserved on the corresponding chassis right above the radiation device so as to allow the scanning ray beams emitted by the radiation device to pass through.

As shown, the radiation device may include a radiation source 101, a shutter 102, a radiation shielding chamber 103, a radiation collimator 104, and an attenuation mechanism 105.

The ray source 101 can use an X-ray machine of 160kV to 450kV, or an electron induction accelerator Betatron of 1MeV to 3MeV, and the field angle of the ray beam emitted by the ray source 101 is large enough (the X-ray machine is not less than 90 degrees) and can be fixed inside the ray shielding chamber 103.

The shutter 102 may be made of a radiation-shielding material having an extremely strong attenuation ability to radiation, such as lead, tungsten, or the like. The radiation window can be closed or opened quickly and tightly for quickly opening and closing the radiation guided to the scanning channel. The shutter 102 can completely block the transmission of the radiation to the safety scanning area when closed, and the shutter 102 can not block any useful radiation from being transmitted to the detection area when opened.

The structure of the ray shielding room 103 can be designed into a labyrinth shape, which surrounds the periphery of the ray source 101, and a slit with a certain width is left on the room surface facing the collimator 104, so that the ray source 101 can be adjusted with multiple degrees of freedom.

The beam collimator 104, which may be composed primarily of lead or an alloy of lead-containing materials, reshapes the radiation emitted by the source into a fan beam plane substantially perpendicular to the direction of traffic through beam slits therebetween. The width of the beam flow seam can be adjusted between 0mm and 10 mm.

An attenuation mechanism 105 is preferably mounted on the collimator 104 and on the beam exit side of the beam slit of the collimator 104 for rapidly and selectively filtering and attenuating the intensity of the radiation at specific locations of the vehicle being scanned to ensure that the dose of the single absorption irradiated at a block of its area is in the ultra-low range.

The damping mechanism 105 may be the damping device described above. In this embodiment, the attenuation mechanism 105 may be designed in a plurality of stages, and the attenuation units of each stage are preferably designed in a straight line arrangement, and may also be designed in a circular arc arrangement, and the attenuation unit array is mounted on the bottom plate. For example, a single layer attenuation unit may be composed of a plurality of attenuation units, each of which may include a high-speed push-pull (preferably a high-speed electromagnet), an attenuation block. Each attenuation unit can independently act under the instruction of the controller, the push rod pushes the attenuation block to rapidly stretch, the ray of the corresponding block is filtered when the attenuation block extends out, and the ray filtering is cancelled when the attenuation block retracts. The actuation execution time of the high-speed push-pull of each attenuation unit is not more than 20ms (preferably not more than 10 ms). The stroke of the extension and contraction is not less than 3mm (20 mm is preferred).

The detectors 106 may be mounted in a detector chamber 107, and the sensitive area centerlines of all detectors may preferably be on one face. The detector cavity 107 may be divided into a left detector cavity and a right detector cavity fixed inside the left and right column frames, and a top detector cavity installed in the upper cross beam frame. Detectors 106 may be disposed in the left detector cavity, the right detector cavity, and the top detector cavity. The cavity of the detector can be flexibly adjusted in multiple degrees of freedom such as left-right, front-back, lifting, pitching, rotating and the like, so that the collimated fan-shaped ray beams can enable the output of the detector to reach the maximum value.

The radiation protection wall 108 may be divided into a left radiation protection wall and a right radiation protection wall, which are respectively connected and installed at the outer sides of the left pillar support and the right pillar support to shield redundant rays.

The dragging device 113 provided in the chassis 1001 may be a chain transmission mechanism. As shown in fig. 9, when the vehicle is dragged by the dragging device 113 for detection, the pushing roller on the dragging device 113 may be higher than the upper surface of the chassis 1001 (i.e. the upper surface of the bottom of the radiation inspection passage), as shown in fig. 11, when the vehicle is driven by a driver for detection, the dragging device 113 may be completely accommodated in the chassis 1001 to ensure that the vehicle can normally run.

The body of the dragging device 113 may be of steel construction to ensure sufficient strength and corrosion resistance, and the dragging device 113 may be mounted in the ground or in a ramp in the direction of travel defined by the radiation inspection tunnel. The dragging device 113 may include a conveying rail 1130, a first pushing roller 11311, a second pushing roller 11312, a conveying device support 1132, a driving device 1133, a transmission chain 1134, a tensioning device 1135, a first position sensor 11361, a second position sensor 11362, a third position sensor 11363, a fourth position sensor 11364, a wheel guider 1137, an anti-derailment sideguard 1138, a parking stopper 1139, a flap 1140, a local operation button box 1141, and a control system (not shown in the figure). The specific components of the dragging device 113 can be referred to the above description, and are not described herein again. Only the parts and contents not mentioned above will be briefly described here.

As shown in fig. 10A and 11A, the derailment prevention side guard 1138 may be designed to have a liftable structure, for example, the derailment prevention side guard 1138 may be composed of a stopper and an elastic member (e.g., a spring). When the vehicle is dragged by the dragging device to pass through, the derailment prevention side blocking device 1138 can be lifted to be higher than the conveying track 1130 so as to prevent the wheels of the vehicle from deviating from the conveying track 1130, and when the vehicle passes through in a driving mode, the derailment prevention side blocking device 1138 can be lowered to be lower than the conveying track 1130 so that normal running of the vehicle is not affected.

Conveyor support 1132 is used for supporting conveying mechanism, and may be a strenghthened type steel structure. According to practical conditions, the slope can be installed on the ground in the slope and also can be installed in a groove below the ground. A slit with a certain width may be left on a bracket beam of a portion of the conveying device bracket 1132 corresponding to the radiation device, so that the radiation beam shaped by the collimator 104 passes through the slit.

The tensioner 1135 is used to adjust the tightness of the chain, and the wheel guide 1137 is used to guide the wheels into the conveying track.

The controller (not shown) of the dragging device can be an electric control system, which can include a control cabinet, a control CPU/PLC, a frequency converter, and the like.

The local operation button box 1141 is provided with an indicator light, a local/remote selection switch, a sudden stop key switch, a positive point, a reverse point, a running and an uploading/ready button and the like; the system is used for debugging and operating the dragging system locally, and when the checked vehicle is parked in place, and a driver and a passenger get off and arrive at a safe area, an operator presses an uploading/ready button, and an operator in a remote control room can perform a vehicle scanning process.

An inlet stop 1111 and an outlet stop 1112 are provided at the inlet on the upstream side and the outlet on the downstream side of the inspection system, respectively. The entrance stop lever 1111 is used for prompting a scanning flow, limiting the traffic flow entering a scanning channel, limiting the entering of an illegal vehicle and the like; the exit bars 1112 are used to limit the flow and clearance of the vehicle. The guard rail 611 serves as a guard rail surrounding the safety zone boundary of the radiation protection zone, so that the illegal entry of irrelevant personnel is avoided. The ladder 612 may facilitate the relative personnel to ascend and descend the ramp.

The scanning process under the embodiment of the invention is as follows:

1) the device starts.

2) And (4) electrifying, initializing and self-checking the system, wherein the system is in a default state. The radiation source 101 is in a state of stopping emission line, or the radiation source 101 is in emission line but the shutter 102 is in a closed state. All the attenuation units are in a retraction state, the ray beams are not shielded by the attenuation blocks, and the scanning channel is emptied.

3) The scan mode is selected and the system defaults to the drag mode.

4) The main operation steps in the dragging mode are as follows:

A. allowing the vehicle to be scanned to enter the scanning passage according to the traffic signal prompt, and guiding the wheel to enter the conveying track 1130 by the wheel guider 1137;

B. the rear edge of the front wheel leaves the third position sensor 11363 to ensure that the front wheel cannot press against the flipper 1140 and the front edge of the front wheel cannot exceed the parking brake 1139;

C. the driver stops the vehicle according to the instructions: a steering wheel is turned right, a neutral gear is engaged, a hand brake is released and the like;

D. the driver and the vehicle occupant get off the vehicle, leave the scanning corridor from the position of the ladder 612, walk from the sidewalk behind the guardrail 611 to the position of the exit-side ladder 612 to wait;

E. after confirming ready, the operator presses the "upload/ready" button on the local operation button box 1141;

F. after the control room operator "confirms" the vehicle, the dragging system is started, the first push roller 11311 starts to be started from below the turning plate 1140, the vehicle is conveyed from the inlet side to the outlet side, and the vehicle position information can be acquired by an information detection unit (not shown in the figure);

G. the information detection unit can send the vehicle position information to the control system, the control system can carry out comprehensive processing according to the received signals and carry out abnormity judgment (such as too low vehicle speed), if abnormity occurs, the scanning is directly interrupted, and the flow is ended; if the result is normal, continuing the following steps;

H. the control system normally controls the ray source to emit/stop rays, the detector and other system components to carry out a scanning process on the vehicle;

I. when the first push roller 11311 travels to the fourth position sensor 11364, the speed starts to be reduced, the vehicle is pushed into the anti-sliding limiting area at a low speed, and when the first push roller 11311 travels to the second position sensor 11362, the dragging system stops;

J. the inspector checks the image to determine whether the image is released, and after the image is released, the driver drives the vehicle to leave the passage, and the vehicle scanning is finished; scanning of the next vehicle is entered.

K. And (6) ending.

5) The main steps in the drive through mode are as follows:

B. the derailment prevention side stop device 1138 and the parking limiter 1139 are all descended to the top of the derailment prevention side stop device to be level with the surface of the conveying rail 1130;

C. waiting for a system ready instruction;

D. after the system is ready, the driver is allowed to drive the vehicle into the scanning lane according to the traffic signal indication, and the wheel aligner 1137 aligns the wheels into the delivery track 1130;

E. the driver drives to continue to move forward, and the information unit acquires the position state and information of the vehicle, sends the position state and information to the control system for comprehensive processing and judges the abnormality. If the abnormal condition occurs, the scanning is directly interrupted, and the flow is ended; if the result is normal, the following steps are continuously executed;

F. when the front end of the vehicle passes through the detection area, the radiation source 101 is controlled to start emitting the scanning ray beam, or the shutter 102 is controlled to be opened so that the scanning ray beam emitted by the radiation source 101 can be normally incident on the detection area.

When a detection-evaded portion (i.e., a region where a person is present) on the vehicle passes through the detection region, the attenuation device is controlled to attenuate the scanning beam emitted from the beam source 101 corresponding to the detection-evaded portion, and when the detection-evaded portion completely passes through the detection region, the attenuation device is controlled to stop attenuation. When the end of the vehicle leaves the detection area, the radiation source 101 is controlled to stop emitting the radiation beam, or the shutter 102 is controlled to close to block the radiation beam emitted by the radiation source 101.

G. The inspector checks the image to determine whether the image is released, and after the image is released, the driver drives the vehicle to leave the passage, and the vehicle scanning is finished; scanning of the next vehicle is entered.

H. And (6) ending.

Example two

Referring to fig. 14-17, fig. 14 is a front view showing a vehicle being subjected to a drag scan using a radiation inspection system constructed according to the present invention; FIG. 15 is a front view showing a vehicle being driven through a scan using a radiation inspection system constructed in accordance with the present invention; FIG. 16 is a side view; fig. 17 is a plan view.

Different from the first embodiment, the radiation inspection system in the present embodiment employs a dual-side dragging device, that is, two dragging devices are respectively disposed on two sides of the radiation inspection channel. And, the dragging device adopts a chain plate/flat plate dragging device. In the following, only the differences are explained, and for the same parts reference is made to the above-mentioned relevant description.

As shown in the figure, the first dragging device 213 and the second dragging device 214 are both single-segment flat plate/chain plate type conveying device structures, are installed at two sides in the radiation inspection channel, and are respectively used for bearing and dragging wheels at two sides of the inspected vehicle, and when the vehicle is conveyed, the first dragging device 213 and the second dragging device 214 keep the speed consistent. The first driving device 213 and the second driving device 214 may share one driving motor and be connected to each other by a transmission shaft, or two driving motors may be used to drive the driving devices on both sides respectively. When the undrawn vehicle or the system is switched to the drive-through mode, the first and

second dragging devices

213 and 214 are in a stopped and braked state, so that the inspected vehicle can drive through the flat plate/chain plate for scanning.

The first and second conveyor supports 2132, 2142 are for supporting a conveyor mechanism and may be of reinforced steel construction. The first and second conveyor supports 2132, 2142 may be mounted on the ground within the ramp or in a trench below the ground, as the case may be. A slit with a certain width may be left on the bracket beam of the portion of the first conveying device bracket 2132 and the second conveying device bracket 2142 corresponding to the radiation device, so that the radiation beam shaped by the collimator 104 passes through the slit.

The first driving device 2133 can provide a strong driving force to drive the first transmission chain plate 2134 and the second transmission chain plate 2144 to move so as to convey the vehicle to be inspected, and the first driving device can be a motor and a speed reducer, and can also be a hydraulic motor and a speed reducer.

The synchronizing shaft 2143 is preferably selected to be a synchronizing shaft for transmitting the force generated by the first driving means 2133 to drive the second link plates 2144 and maintain synchronization with the speed of the first link plates 2134. Alternatively, a second driving device may be provided, which may be a motor and a speed reducer, or a hydraulic motor and a speed reducer, etc.

The first and second

drive link plates

2134 and 2144 are configured to carry wheels and a vehicle body and, in a vehicle towing mode, to transport the vehicle from the entrance side to the exit side.

The first tensioning device 2135 and the second tensioning device 2145 are used for adjusting the tightness of the plate link chain.

The scanning process in the embodiment of the present invention is basically the same as the process in the first embodiment, and will not be described herein again, except that in the dragging mode, it is necessary to ensure that all the wheels of the vehicle fall on the transmission chain plate.

The radiation inspection system according to the present invention has been described in detail hereinabove with reference to the accompanying drawings.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A radiation inspection system for radiation inspection of a inspected object traveling along a direction of travel defined by a radiation inspection tunnel, the system comprising:

the radiation device is arranged at the bottom of the radiation inspection channel and is used for emitting scanning ray beams to a detection area;

one or more detectors disposed at the top and/or sides of the radiation inspection channel for receiving imaging beams transmitted or scattered from inspected objects in the inspection area;

the dragging device is arranged on one side or two sides of the width direction perpendicular to the advancing direction in the radiation inspection channel, the upper surface of the dragging device is basically level with the upper surface of the bottom of the radiation inspection channel, and the dragging device is used for dragging the detected object to advance along the advancing direction; and

the control device controls the radiation device to emit scanning ray beams to the detection area in a first working mode under the condition that the detected object passes through the radiation inspection channel under the driving action of the control device, and controls the radiation device to emit scanning ray beams to the detection area in a second working mode under the condition that the detected object passes through the radiation inspection channel under the dragging action of the dragging device;

wherein the radiation device comprises:

a scanning device for emitting a scanning beam to the detection area; and

the attenuation device has a plurality of working modes, and the attenuation device attenuates the intensities of the scanning ray beams of different parts emitted by the scanning device under different working modes;

wherein the detected object comprises a part to be detected and a detection evasion part,

in the first working mode, when the control device determines that the leading edge of the detection and avoidance part of the detected object reaches the detection area according to the area distribution information of the detection and avoidance part of the detected object, the attenuation unit which participates in working in the attenuation device, in the process that the detection and avoidance part of the detected object passes through the detection area, the attenuation device attenuates the intensity of the scanning ray beam which is emitted by the scanning device and corresponds to the detection and avoidance part based on the determined attenuation unit which participates in working so as to enable the absorption dose rate of the detection and avoidance part to be lower than a preset threshold value,

in the second mode of operation, the attenuation device does not attenuate the intensity of the scanning beam emitted by the scanning device.

2. The radiation inspection system of claim 1, wherein the dragging device comprises: a closed loop conveyor having an upper surface substantially level with an upper surface of the bottom of the radiation inspection tunnel, the closed loop conveyor having an upper surface with a conveying direction substantially coincident with the direction of travel.

3. The radiation inspection system of claim 2, wherein at least one push roller is provided on the closed loop transport mechanism, the push roller being driven by the closed loop transport mechanism to push the inspected object to travel along the travel direction.

4. The radiation inspection system of claim 3, wherein the closed-loop transport mechanism comprises:

a driving device for providing a driving force;

the pushing roller is arranged on the closed-loop conveying chain and used for driving the pushing roller to move along the conveying direction under the driving action of the driving device, and when the pushing roller moves to the upper surface of the closed-loop conveying chain, the pushing roller is higher than the upper surface of the bottom of the radiation inspection channel.

5. The radiation inspection system of claim 3, further comprising: a flap movably disposed between a starting position at an upstream side of the closed-loop transport mechanism and the radiation inspection passage,

after the dragging part of the detected object moves onto the closed-loop conveying mechanism along the turning plate, the pushing roller pushes up the turning plate under the driving of the closed-loop conveying mechanism and moves to the upper surface of the closed-loop conveying mechanism.

6. The radiation inspection system of claim 2, further comprising:

one or more sensors respectively arranged at the starting position at the upstream side and/or the ending position at the downstream side of the closed-loop conveying mechanism and used for detecting the time information when the detected object passes through the starting position and/or the ending position.

7. The radiation inspection system of claim 2, further comprising:

and the limiting device is arranged between the end position of the downstream side of the closed-loop conveying mechanism and the radiation inspection channel and used for limiting the detected object at a fixed position when the closed-loop conveying mechanism finishes dragging the detected object.

8. The radiation inspection system of claim 1, further comprising:

an information acquisition device, provided at a predetermined distance upstream from the detection region within the radiation inspection passage, for acquiring relative position information between a plurality of characteristic portions of the detected object, the plurality of characteristic portions including at least a leading edge and a trailing edge of the detection avoidance portion,

the control device determines the area distribution information of the detection avoidance part according to the relative position information among the plurality of characteristic parts.