CN102175697A - Object inspecting system, DR imaging device and CT imaging device - Google Patents

Abstract

The invention discloses an object inspecting system, which comprises a transmission path and a digital radiography (DR) imaging device arranged along the transmission path, wherein the DR imaging device is provided with a DR data acquisition trigger module; and when objects pass through every preset distance A along the transmission path in the process of passing through the DR imaging device, the DR data acquisition trigger module triggers the DR imaging device to perform data acquisition.

Description

Item inspection system, DR imaging device and CT imaging device

This application is a divisional application of the patent application with the application number 200910088630.8, the application date is June 30, 2009, and the invention title is "article inspection system, DR imaging system and CT imaging system".

technical field

The present invention relates to an item inspection system, wherein the item inspection system includes a CT imaging device and a DR imaging device. The invention also relates to a DR imaging device and a CT imaging device.

Background technique

Among the numerous explosives inspection methods, the CT-type explosives inspection system has become the main block explosives inspection method in the field of aviation security inspection due to its low false alarm rate and false negative rate. However, traditional CT products are bulky and expensive, and their development is greatly restricted.

In recent years, improved CT-type explosive inspection systems have been proposed, which are small in size and low in price. However, compared with the traditional CT-type EDS, its passing speed is greatly reduced, which has also become the bottleneck of its promotion.

In addition, an explosive inspection system including a DR imaging device and a CT imaging device has appeared on the market. DR imaging devices generally use a time-triggered mode to collect data on items, that is, the DR imaging system emits beams every predetermined time period, and the detector converts the rays that penetrate the items into digital information. This time-triggered mode requires a uniform relative velocity between the DR imaging device and the object.

However, while increasing the DR imaging device, it also increases the length of the explosives inspection system, and because the inspection speed of CT technology is lower than that of the DR imaging device, it also reduces the speed of items passing through the explosives inspection system. In order to keep the external dimension of the explosive inspection system small, its increased length must be as small as possible, so the distance between the CT imaging device and the DR imaging device must be sufficiently small.

In addition, when the size of the object is larger than the beam distance between the CT imaging device and the DR imaging device, it may happen that the object undergoes DR and CT scanning at the same time. For this reason, in the prior art, the speed of the item passing through the DR imaging device is the same as that passing through the CT imaging device.

The problem is that the DR imaging device takes much less time to image than the CT imaging device, which means that the whole system can only work at the speed that the slower CT imaging device is suitable for. At this time, if the system can be made to work in the faster DR scanning mode during DR imaging, and in the slower CT scanning mode when CT and DR are simultaneously scanned, the rate of items passing through the explosives inspection system can be improved as much as possible. average speed. But in this case, it means that the same item is scanned by DR at different speeds. If it is not controlled, the resulting image will be deformed (as shown in Figure 2), which will reduce the technical performance of the explosives inspection system.

Contents of the invention

The present invention is made to overcome at least one aspect of the defects and deficiencies in the prior art.

According to an aspect of the present invention, there is provided an article inspection system for inspecting articles conveyed along a conveying path, the article inspecting system comprising a DR imaging device and a CT imaging device disposed upstream or downstream of the DR imaging device along the conveying path , wherein the average velocity of items passing through the DR imaging device is greater than the average velocity of items passing through the CT imaging device.

Optionally, the DR imaging device includes a DR data collection trigger module, and when the item passes through the DR imaging device, each time the item passes a predetermined distance A along the transmission path, the DR data collection trigger module Data acquisition is performed on triggering the DR imaging device.

Further optionally, the DR data collection trigger module includes a rotary encoder arranged on the transmission path, and every time the rotary encoder rotates an angle, it sends a trigger signal to the DR data collection trigger module, wherein the rotary encoder sends a trigger signal to the DR data collection trigger module every time A rotation by an angle corresponds to said predetermined distance A being traversed by said article along said transport path.

Alternatively, the DR data collection trigger module includes a plurality of position markers arranged at intervals of the predetermined distance A on the transmission path and a marker detector for detecting passing of the position markers, wherein the marker detector is A trigger signal is sent to the DR data acquisition trigger module when a position marker is detected to pass by.

According to another aspect of the present invention, an item inspection system is proposed, which includes: a transmission path; and a DR imaging device arranged along the transmission path, wherein the DR imaging device has a DR data acquisition trigger module, and when the item passes through the DR imaging During the process of the device, when the item passes a predetermined distance A along the conveying path, the DR data collection trigger module triggers the DR imaging device to collect data.

According to still another aspect of the present invention, a DR imaging device is proposed, which is used to scan an item conveyed along a conveying path to form an image of the item, the DR imaging device comprising: an X-ray source; A passing detector; a digital image processing unit; and a DR data acquisition trigger module, when the item passes through a predetermined distance A along the transmission path during the process of the item passing through the DR imaging device, the DR data acquisition trigger The module triggers the DR imaging device for data acquisition.

According to yet another aspect of the present invention, a CT imaging device is provided, which is used to scan an item conveyed along a conveying path to form an image of the object, comprising: an X-ray source; a detector for detecting the passing of the object; A digital image processing unit; and a CT data acquisition trigger module, when the item passes through the CT imaging device, when the item passes a predetermined distance B along the conveying path, the CT data acquisition trigger module triggers the CT imaging device Perform data collection.

Description of drawings

The present invention will become more apparent by describing in detail embodiments of the invention with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of the composition of the article inspection system;

Figure 2 is a schematic diagram of a DR diagram obtained without distance triggering, wherein Figure 2a is a cross-sectional view of an item, and Figure 2b is a DR diagram of an item; and

Fig. 3 is a schematic diagram of a DR map obtained by distance triggering, wherein Fig. 3a is a cross-sectional view of an item, and Fig. 3b is a DR map of an item.

Detailed ways

The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals designate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention, but should not be construed as a limitation of the present invention.

As mentioned above, the image formed by scanning the same item in the trigger mode with equal time intervals at different speeds will be deformed (as shown in Figure 2). Therefore, it is still difficult to solve the problem of image distortion when DR and CT scanning are performed simultaneously on an item in the prior art.

Considering the above problems, the present invention proposes an item inspection system 100, which may be an explosives inspection system or other systems for identifying passing items. As shown in FIG. 1 , an article inspection system 100 is used to inspect an article 9 conveyed along a conveying path 4, and includes a DR imaging device 1 and a CT imaging device 10 disposed downstream of the DR imaging device 1 along the conveying path 4, wherein the article 9 The average speed passing through the DR imaging device 1 is greater than the average speed of the object 9 passing through the CT imaging device 10 . It should be noted that although the DR imaging device 1 is located upstream of the CT imaging device 10 in FIG. 1 , the DR imaging device 1 may also be located downstream of the CT imaging device 10 .

The DR imaging device 1 may include a DR data collection trigger module 2, and when the item 9 passes through the DR imaging device 1, each time the item 9 passes a predetermined distance A along the transmission path 4, the DR data The acquisition trigger module 2 triggers the DR imaging device 1 to perform data acquisition. Wherein, the DR data collection trigger module 2 includes a rotary encoder 3 arranged on the transmission path 4, and the rotary encoder 3 sends a trigger signal to the DR data collection trigger module 2 every time it rotates an angle, wherein the rotary encoder 3 Each rotation of the device 3 by an angle corresponds to the passage of the predetermined distance A by the article 9 along the conveying path 4 . Alternatively, the DR data collection trigger module 2 includes a plurality of position markers (not shown) arranged at intervals of the predetermined distance A on the transmission path 4 and a marker detector (not shown) for detecting passing of the position markers ( not shown), wherein the marker detector sends a trigger signal to the DR data collection trigger module 2 every time a position marker is detected passing by.

Of course, the DR data collection triggering module 2 may use a time trigger to trigger the DR imaging device to collect data every time the item passes a predetermined distance A along the conveying path. That is, when a time elapses, and the transmission path passes through the predetermined distance A within this time period, the DR data collection trigger module 2 triggers the DR imaging device to perform data collection.

The CT imaging device 10 wherein may also include a CT data acquisition trigger module 5 (with a similar function to the DR data acquisition module), and during the process of the item 9 passing through the CT imaging device 10, the item 9 along the The CT data collection trigger module 5 triggers the CT imaging device 10 to collect data every time the transmission path 4 passes a predetermined distance B, wherein the predetermined distance B is equal to or not equal to the predetermined distance A. Similarly, the CT data acquisition trigger module 5 may include a rotary encoder (not shown) arranged on the transmission path 9 for the CT imaging device 10, and the CT data The acquisition trigger module sends a trigger signal, wherein each rotation of the rotary encoder corresponds to the item 9 passing a predetermined distance B along the conveying path 4 . Similarly, the CT data acquisition trigger module 5 includes a plurality of position markers (not shown) arranged at intervals of the predetermined distance B on the transmission path 4 and a marker detector for detecting passing of the position markers (not shown), wherein the marker detector sends a trigger signal to the CT data acquisition trigger module every time it detects the passing of a position marker. Likewise, the CT data collection triggering module may use a time trigger to trigger the CT imaging device to collect data every time the item passes a predetermined distance B along the conveying path. That is, when a time elapses, and the transmission path passes through the predetermined distance B within this time, the CT data acquisition triggering module triggers the CT imaging device to perform data acquisition.

The CT imaging device 10 and the DR imaging device 1 may also share a rotary encoder or a marker detector.

As shown in FIG. 1 , the article inspection system 100 also includes a detector C located at a predetermined distance C in front of the downstream imaging device (CT imaging device 10 in FIG. 1 ) for detecting the front end of the article 4 passing through. After C detects that the front end of the object 4 passes, the imaging device downstream starts data collection.

Alternatively, the article inspection system 100 further includes a detector D located at a predetermined distance D in front of the downstream imaging device for detecting the passage of the front end of the article, wherein after the detector D detects that the front end of the article 9 passes through, the transmission path passes through the Decelerate from the first speed to the second speed within the predetermined distance D, so that the downstream imaging device starts data collection, or accelerate from the second speed to the first speed, so that the downstream imaging device starts data collection.

Reference numeral 7 in FIG. 1 denotes a detector C or a detector D. As shown in FIG.

The item inspection system 100 also includes an upstream detector 6 located in front of the upstream imaging device for judging that the front end of the item 9 passes. When the upstream detector 6 detects that the front end of the item 9 passes, the upstream imaging device starts data collection. Of course, the article inspection system 100 may also include a downstream detector 8 behind the imaging device positioned downstream for judging that the rear end of the article passes through. After that, when the upstream detector 6 does not detect the passage of the article 9, the article inspection system 100 stops checking or is in a standby state.

It should be noted that in this specification, the front end of the article 9 passes through, which means that the front end of the article 9 passes through the upstream detector 6 or detector 7 (detector C or detector D); the rear end of the article 9 passes through It means that the rearmost edge of the rear end of the article 9 passes the downstream detector 8 . In addition, in this specification, the upstream detector 6, the detector 7 and the downstream detector 8 can all be set as photoelectric switches. Moreover, in this specification, the predetermined distances A and B may vary from several millimeters to several centimeters according to inspection accuracy requirements, and the transmission path 4 may also be a conveyor belt moving in a loop.

Another embodiment of the article inspection system according to the present invention is discussed below.

An item inspection system 100', comprising: a transmission path 4; and a DR imaging device 1 arranged along the transmission path 4, wherein the DR imaging device 1 has a DR data acquisition trigger module 2, and when an item 9 passes through the DR imaging device 1 During the process, when the item 9 passes a predetermined distance A along the conveying path 4, the DR data collection trigger module 2 triggers the DR imaging device 1 to collect data.

The article inspection system 100 ′ also includes a CT imaging device 10 arranged upstream or downstream of the DR imaging device 1 along the transport path 4 . Wherein, the average speed of the item 9 passing through the DR imaging device 1 is greater than the average speed of the item 9 passing through the CT imaging device 10 . The CT imaging device 10 may also include a CT data acquisition trigger module 5, and during the process of the item 9 passing through the CT imaging device 10, each time the item passes through a predetermined distance B along the conveying path 4, the CT The data acquisition triggering module 5 triggers the CT imaging device 10 to perform data acquisition, wherein the predetermined distance B is equal to or not equal to the predetermined distance A; The detector C is used to detect the passage of the front end of the article 9. When the detector C detects the passage of the front end of the article 9, the downstream imaging device starts data collection.

Optionally, the article inspection system 100' further includes a detector D located at a predetermined distance D in front of the downstream imaging device for judging that the front end of the article passes. After the detector D detects that the front end of the article passes, the transmission path is Decelerate from the first speed to the second speed within the predetermined distance D, so that the downstream imaging device starts data collection, or accelerate from the second speed to the first speed, so that the downstream imaging device starts data collection.

Reference numeral 7 in FIG. 1 denotes a detector C or a detector D. As shown in FIG.

The article inspection system 100' also includes a downstream detector 8 behind the downstream imaging device for judging the passage of the rear end of the article. When the downstream detector 8 detects that the rear end of the article passes and after a predetermined time, the upstream detector 6 When no item is detected to pass through, the item inspection system stops checking or is in a standby state.

In addition, the present invention relates to a DR imaging device 1 for scanning an item 9 transported along the transport path 4 to form an image of the item 9, comprising: an X-ray source (not shown); a detector; a digital image processing unit; and a DR data acquisition trigger module 2, when the item 9 passes through a predetermined distance A along the conveying path 4 during the process of the item 9 passing through the DR imaging device 1, the The DR data acquisition trigger module 2 triggers the DR imaging device 1 to perform data acquisition. That is to say, the DR data acquisition trigger module 2 triggers the DR imaging device 1 to perform data acquisition in the distance trigger mode, and every time the item 9 on the transmission path 4 passes through a predetermined distance A (in any form), the DR data acquisition trigger module 2 will be triggered to control the DR imaging device 1 to emit beams and perform data acquisition. The DR imaging device 1 controlled in the distance trigger mode will not be affected by the relative speed between the DR imaging device 1 and the object 9, no matter whether the speed is fast or slow or not.

In order to realize the distance trigger mode, the DR data acquisition trigger module 2 includes a rotary encoder 3 arranged on the transmission path 4, and the rotary encoder 3 sends a trigger signal to the DR data acquisition trigger module 2 every time it rotates an angle , wherein each rotation of the rotary encoder 3 corresponds to a predetermined distance A passed by the item 9 along the conveying path 4 . Regardless of the rotation speed of the rotary encoder 3, as long as it rotates through an angle, it will send a trigger signal. Here, the end of the rotary encoder 3 may include a gear, and the gear teeth of the gear are in rolling contact with the transmission path 4, so that the transmission path 4 advances a predetermined distance A, and the gear rotates by a predetermined angle. The rotary encoder 3 can also adopt other forms, as long as it can realize that the transmission path 4 advances a predetermined distance A, it will rotate by a predetermined angle. Alternatively, the DR data collection trigger module 2 includes a plurality of position markers (not shown) arranged at the predetermined distance A along the transmission path 4 and a marker detector (not shown) for detecting passing of the plurality of position markers ( not shown), wherein the marker detector sends a trigger signal to the DR data collection trigger module 2 every time a position marker is detected passing by.

However, the CT imaging device 10 may also adopt the above-mentioned distance trigger mode. Therefore, the present invention also relates to a CT imaging device 10 for scanning an object 9 conveyed along the conveying path 4 to form an image of said object 9, the CT imaging device 10 comprising: an X-ray source; 9 passing detectors; a digital image processing unit; and a CT data acquisition trigger module 5, when the item 9 passes through the CT imaging device 10, when the item 9 passes through a predetermined distance B along the transmission path 4, the The CT data acquisition trigger module 5 triggers the CT imaging device 10 to perform data acquisition.

The operation process of the article inspection system 100 according to the present invention will be described in detail below by way of example with reference to FIG. 1 .

As shown in FIG. 1 , the DR imaging device 1 is located in the direction of the entrance of the article inspection system 100 , while the CT imaging device 10 is located in the direction of the exit. The operation process of the article inspection system 1 is as follows:

(1) The article 9 enters the entrance of the article inspection system 100 at a relatively high speed on the transport path 4 .

(2) After the front end of the article 9 passes through the upstream detector 6 located in front of the DR imaging device 1 , the DR imaging device 1 emits the beam, and the DR data collection trigger module 2 starts to work.

(3) The DR data acquisition trigger module 2 works in the distance trigger mode. The rotary encoder 3 rotates together with the movement of the conveying path 4, for example, by rolling contact with the conveying path 4, and every time the conveying path 4 moves a distance, the rotary encoder 3 rotates by an angle, and the rotary encoder 3 rotates by an angle every time it rotates. The DR data acquisition trigger module 2 sends out a trigger signal. Therefore, the DR imaging device 1 collects data every certain distance (for example, a certain displacement of the transmission path 4 ), and the collected data is processed to form a DR image.

(4) When the object 9 is at a predetermined distance from the front of the CT imaging device 10 (for example, the distance from the CT beam surface is a certain position greater than 2 times the thickness of the CT slice), or when the front end of the object 9 passes the detector 7 upstream of the CT ( detector D), the transmission path 4 is controlled to decelerate, and the transmission path 4 decelerates to a lower first speed and travels at a constant speed within the predetermined distance (for example, at a place where the distance from the CT beam plane is the thickness of the scanning layer), and at the same time starts to trigger the CT The imaging device 10 emits a beam for data collection.

(5) The CT data acquisition trigger module 5 controls the CT imaging device 10 to output the beam according to the time trigger mode, so as to perform data acquisition at regular intervals, process the acquired data, form a CT image, and automatically analyze the CT image , for substance identification. Give the perspective view and tomogram of the item, and call the police if necessary. However, as mentioned above, the CT data collection trigger module 5 may also control the CT imaging device 10 to emit beams according to the distance trigger mode.

(6) If the length of the item 9 is greater than the distance between the DR beam surface and the CT beam surface, the condition that the item 9 undergoes DR scanning and CT scanning at the same time will occur. Since the data collected during the DR scan is triggered by the distance trigger mode, the image is collected The frequency has nothing to do with the running speed of the transmission path 4, thereby ensuring the acquisition quality of DR images.

(7) When the rear end of the article 9 passes through the downstream detector 8 behind the CT imaging device 10, and after a certain period of time (determined according to the on-site implementation), when no article 9 enters the upstream detector 6 before the DR imaging device 1, the article The inspection system 100 stops the inspection, or enters a standby state.

Perform distance triggering on the DR data acquisition trigger module, so as to realize the stability of image quality under the condition of different transmission path speeds. In the acquisition process, the DR acquisition applies the distance trigger mode, so variable speed acquisition can be realized. Therefore, in the transmission path of the item inspection system, DR acquisition can be performed at a higher speed first, then CT acquisition and DR acquisition can be performed simultaneously at a lower speed, and finally CT acquisition can be performed at a lower speed. When the CT imaging device is set upstream of the DR imaging device, the items in the transmission path of the item inspection system can first perform CT acquisition at a low speed, and then perform CT acquisition and DR acquisition at a lower speed at the same time, and finally perform a comparison DR acquisition at high speed. It can be seen that the article inspection system and inspection method of the present invention can improve the speed of articles passing through the article inspection system while ensuring good image quality (as shown in FIG. 3 , the image obtained by DR acquisition according to the present invention is not deformed).

The invention has been described with reference to the exemplary embodiments. However, it is obvious that many alternative modifications and changes will be apparent to those skilled in the art under the teaching of the above description. Accordingly, the present invention embraces all alternative modifications and changes falling within the spirit and scope of the appended claims.

Claims (11)

1. An item inspection system, comprising: transmission path; and a DR imaging device arranged along the transport path, Wherein the DR imaging device has a DR data acquisition trigger module, and when the item passes through a predetermined distance A along the transmission path during the process of the item passing through the DR imaging device, the DR data acquisition trigger module triggers the DR imaging device for data collection. 2. The article inspection system of claim 1, wherein: The article inspection system also includes a CT imaging device arranged upstream or downstream of the DR imaging device along the transport path. 3. The article inspection system of claim 2, wherein: The average velocity of the item through the DR imaging device is greater than the average velocity of the item through the CT imaging device. 4. The article inspection system of claim 3, wherein: The CT imaging device includes a CT data acquisition trigger module, and when the item passes through the CT imaging device, each time the item passes a predetermined distance B along the conveying path, the CT data acquisition trigger module triggers the CT The imaging device performs data collection, wherein the predetermined distance B is equal to or not equal to the predetermined distance A; The article inspection system also includes a detector C located at a predetermined distance C in front of the downstream imaging device for detecting the passage of the front end of the article. When the detector C detects the passage of the front end of the article, the downstream imaging device starts data collection. 5. The article inspection system of claim 3, wherein: The article inspection system also includes a detector D located at a predetermined distance D in front of the downstream imaging device for judging that the front end of the article passes. The first speed is decelerated to the second speed to initiate data acquisition at the downstream imaging device, or accelerated from the second speed to the first speed to initiate data acquisition at the downstream imaging device. 6. The item inspection system of claim 2, wherein: The item inspection system further includes an upstream detector located in front of the upstream imaging device for judging that the front end of the item passes. When the upstream detector detects that the front end of the item passes, the upstream imaging device starts data collection. 7. The item inspection system of claim 6, wherein: The article inspection system also includes a downstream detector behind the imaging device located downstream for judging the passage of the rear end of the article. When the downstream detector detects that the rear end of the article passes and a predetermined time elapses, the upstream detector does not detect the passage of the article. , the item inspection system stops checking or is in a standby state. 8. A DR imaging device for scanning an item transported along a transport path to form an image of said item, comprising: X-ray source; Detectors for detecting the passage of objects; digital image processing unit; and The DR data acquisition triggering module is configured to trigger the DR imaging device to collect data when the item passes through a predetermined distance A along the conveying path during the process of the item passing through the DR imaging device. 9. The DR imaging device of claim 8, wherein: The DR data acquisition trigger module includes a rotary encoder arranged on the transmission path, and the rotary encoder sends a trigger signal to the DR data acquisition trigger module every time it rotates an angle, wherein each rotation angle of the rotary encoder corresponds to The article traverses a predetermined distance A along the conveying path. 10. The DR imaging device of claim 8, wherein: The DR data collection trigger module includes a plurality of position markers arranged at the predetermined distance A along the transmission path and a marker detector for detecting passing of the plurality of position markers, wherein the marker detector detects When a position mark passes, a trigger signal is sent to the DR data acquisition trigger module. 11. A CT imaging apparatus for scanning an item conveyed along a conveyance path to form an image of said item, comprising: X-ray source; Detectors for detecting the passage of objects; digital image processing unit; and The CT data acquisition triggering module is configured to trigger the CT imaging device to collect data when the item passes through a predetermined distance B along the conveying path during the process of the item passing through the CT imaging device.

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