CN105004741A - Rapid and automatic quarantine contraband screening method based on X-ray article machine-based and device thereof - Google Patents

Abstract

The invention relates to the technical field of inspection and quarantine contraband inspection at inspection and quarantine ports, and in particular to a method and device for quickly and automatically screening quarantine contraband based on an X-ray article machine. The steps of the method are as follows: start the automatic screening of workstations and terminals, check whether the initialization of the workstations and terminals is normal, check whether the data in the quarantine feature database of the workstations are synchronized, check whether the terminal detector response curves are updated, and automatically screen whether the items are quarantine contraband. The device includes a frame, an L-shaped detector frame, a detector array collimator, a detector array, an X-ray source, an electric roller and a conveyor belt, an X-ray photon, a phantom container fixing frame for calibration, and a phantom container for calibration , Quarantine prohibited object imitation for calibration, object machine screening channel, channel baffle, hand inspection channel and non-contraband channel. The invention can quickly and automatically screen all the items in the mail bags entering the inspection and quarantine port in an all-weather, low false alarm, high efficiency and non-interfering manner with the same standard.

Description

A method and device for rapid and automatic screening of quarantine contraband based on an X-ray article machine

technical field

The invention relates to the technical field of inspection and quarantine contraband inspection at inspection and quarantine ports, and in particular to a method and device for quickly and automatically screening quarantine contraband based on an X-ray article machine.

Background technique

With the continuous deepening of global economic integration, the international flow of people is becoming more and more frequent. Once high-quarantine risk substances invade our country through passenger mail, it will cause immeasurable losses to the ecological environment and agricultural production. How to prevent and control the invasion of high-quarantine risk substances at the first line of defense at the border - inspection and quarantine ports has become an urgent task. At inspection and quarantine ports, the traditional inspection technology for quarantine contraband often adopts a combination of manual spot checks and quarantine dog patrols. The method of manual spot check relies on the security staff to randomly check the passenger's carry-on postal parcels manually. This method has two main disadvantages: first, it is very easy to miss inspection due to random selection; second, the work efficiency of manual checking is relatively low. Low. The patrolling method of quarantine dogs mainly relies on the sensitive sense of smell of quarantine dogs to check for prohibited objects. This method has three main shortcomings: First, the time of olfactory excitement of quarantine dogs is relatively short, so they cannot work around the clock; second, even strictly trained quarantine dogs Dogs are also easily misled by their own preferences or external interference, resulting in a high rate of false alarms; third, quarantine dogs are likely to cause panic or anxiety to some passengers when they are on duty. The dual-energy, line-scanning, and transmission-type X-ray security inspection machines commonly used in the field of public security now mainly separate inorganic substances from organic substances, focusing on detecting prohibited substances such as metal weapons and knives, while quarantine prohibited substances are all organic substances. It is difficult for X-ray security inspection machines to perform qualitative and quantitative screening.

Contents of the invention

In order to solve the above problems, the present invention provides a method and device for rapid and automatic screening of quarantine contraband based on an X-ray article machine, which can quickly and automatically screen quarantine contraband at inspection and quarantine ports that are synchronized with the quarantine feature database of the AQSIQ data center. The screening workstation can control the rapid and automatic screening terminal of all quarantine prohibited items in the local area network of the local inspection and quarantine port, and can check all the items in the parcels entering the inspection and quarantine port with the same standard in an all-weather, low false alarm, high efficiency, and non-interfering manner Carry out rapid and automatic screening, guard our country's borders, protect the ecological environment and the safety of agricultural production.

The technical scheme of invention is as follows:

The present invention is based on the X-ray article machine to carry out the method for fast and automatic screening of quarantine contraband, comprising the following steps:

S1: After starting the automatic screening workstation and terminal, check whether the initialization of the workstation and terminal is normal, if not normal, alarm, if normal, execute downward in order;

S2: Check whether the quarantine signature database data of the workstation is synchronized. If synchronization is required, the workstation is connected to the AQSIQ data center through the optical fiber backbone network, and the latest quarantine signature database data downloaded is synchronized. If synchronization is not required, it is executed sequentially;

S3: Regularly start the task of updating the response curve of the terminal detector. If it needs to be updated, insert the calibration phantom into the corresponding terminal to update the segmental fitting response curve of the terminal detector. If it does not need to be updated, execute it in order;

S4: Check whether the workstation has received the end screening command. If the command is received, stop the automatic screening of the workstation and terminal real-time online screening task. If the corresponding command is not received, execute it in order; real-time online screening of the terminal Whether the item in the channel is a quarantine prohibited item, if the item is not a prohibited item, it will be executed in order; if the item is judged to be a prohibited item under automatic screening, an alarm will be triggered immediately to notify the staff next to the manual inspection channel, and the conveyor belt movement will Switch the suspected prohibited items in the channel to the manual inspection channel for inspection. If the items are confirmed to be prohibited items after manual inspection by the staff, they will be immediately isolated, destroyed or returned according to the regulations, and executed in sequence; After the manual inspection, it is confirmed that the items are not prohibited items, and the items are released immediately, and executed in sequence.

Among them, when checking whether the quarantine signature database data of the workstation is synchronized, the AQSIQ data center cluster server will respond to the data center quarantine signature database version number information requested by all workstations in the national quality inspection system intranet through the optical fiber backbone network, and the workstation only needs to By comparing the latest version number received with its local version number, it can be determined whether the workstation needs to download the quarantine signature database from the AQSIQ data center cluster server and update the local data.

The workstations are connected to the AQSIQ data center cluster server through the optical fiber backbone network, and are connected to and manage all terminal X-ray item machines in the local inspection and quarantine port LAN through the star LAN.

Among them, the AQSIQ will update the quarantine feature database data in its data center in a timely manner according to the new quarantine contraband intercepted by inspection and quarantine ports across the country, so as to ensure the rapid and efficient response of inspection and quarantine port workstations and terminals to contraband.

Among them, after updating the response curve of the terminal detector with the phantom for calibration, all terminal X-ray item machines at various inspection and quarantine ports across the country can obtain the same item profile and X-ray intensity absorption value on the detector when inspecting the same item. .

Among them, when the workstation controls the terminal to automatically screen whether the items in the channel are quarantine prohibited items, the workstation can obtain the status information of the terminal through the LAN status and command bus and issue commands, and let the terminal upload its scan to get the X-ray of the item through the LAN video bus The intensity absorption value is sent to the image processing module connected to the workstation, and the object outline and feature data obtained by the algorithm are compared with the local quarantine feature database of the workstation to complete the task of rapid and automatic screening of quarantine contraband.

Preferably, the image processing module is common to all terminals in the local area network, and can convert the item outline and X-ray intensity absorption value transmitted from the fast processing terminal into item characteristic data through the embedded information processing algorithm.

The device for rapid and automatic screening of quarantine contraband based on the X-ray article machine provided by the present invention includes a frame, an L-shaped detector frame, a detector array collimator, a detector array, an X-ray source, an electric drum and a conveyor belt, X-ray photons, phantom container fixing frame for calibration, phantom container for calibration, quarantine contraband phantom for calibration, item machine screening channel, channel baffle, hand inspection channel, non-contraband channel and conveyor belt movement direction.

Preferably, the focal spot size of the X-ray source is 0.5mm, the maximum tube voltage is 100kV, and the maximum output power is 150W.

Preferably, a high-low dual-energy detector is used in the detector array, and the pixel size of the miniature silicon photodiode is 0.8mm.

Wherein, when the phantom container for calibration is placed at a limited position on the fixed frame of the phantom container for calibration, the X-ray photons on the line connecting the central point of the phantom of the quarantine prohibited object for calibration and the X-ray source will be vertically incident on the detector array.

Among them, the channel baffle can send the checked items in the channel to the non-contraband channel or the manual inspection channel according to the command of the workstation.

The main technical features of the invention are:

1. According to the idea of AQSIQ to strengthen the top-level design, in the present invention, due to the regular update of the quarantine feature library data in the AQSIQ data center, the latest feature library data is pushed to all workstations in the national quality inspection system intranet in time-sharing, It can ensure that the rapid and automatic screening terminals for quarantine contraband at each inspection and quarantine port have consistent implementation standards.

2. The present invention is based on a hybrid topology network, and the fast and automatic screening workstations for contraband at each inspection and quarantine port are externally connected to the AQSIQ data center through an optical fiber backbone network bus structure, and internally connected through a star structure to manage local inspection and quarantine ports All terminal X-ray item machines in the LAN.

3. In the present invention, under the control of the workstation, all terminal X-ray object machines in the local area network of each inspection and quarantine port multiplex a high-performance image processing module in time division. The advantage of such a design is that it reduces the hardware configuration requirements of each terminal X-ray object machine, and reduces the manufacturing and maintenance costs of the device.

4. In the present invention, the phantom is introduced for calibration to correct the L-type detector response curve in the fast automatic screening terminal of all contraband at the inspection and quarantine port. In this way, it can be ensured that all terminal X-ray item machines can check the same item. Obtain the same X-ray intensity absorption value of the item on the detector to provide accurate and credible data for the subsequent image processing module to extract the outline and feature information of the item.

5. In the present invention, the non-contraband channel and the manual inspection channel are designed, and while ensuring the normal customs clearance speed of the non-quarantine contraband, the manual inspection channel is connected with the normal quarantine contraband processing operation process.

6. Aiming at the shape of quarantine contraband and its weak absorption characteristics under X-ray irradiation, the present invention selects an X-ray source with a focal spot size of 0.5mm, a maximum tube voltage of 100kV, and a maximum output power of 150W, as well as a micro-silicon photoelectric A detector array with a diode pixel size of 0.8mm that can collect high and low energy signals.

The advantages of the invention are:

1. It is in line with the idea of strengthening the top-level design of the AQSIQ. It is convenient to implement the same screening standards for contraband across the country, which is conducive to the standardization of law enforcement at inspection and quarantine ports.

2. Customized design for rapid and automatic screening tasks of quarantine contraband. When designing a device for rapid and automatic screening of quarantine contraband based on an X-ray object machine, a small-focus low-voltage X-ray source and a detector with high spatial resolution were selected.

3. It is simple and convenient to correct the terminal detector response curve. Simply place the calibration phantom container embedded with equivalent quarantine contraband at a limited position on the fixed frame, run the terminal equipment, and start the automatic calibration process of the detector response curve, and finally realize the type of quarantine contraband and the detector Correspondence between X-ray intensity absorption values is obtained.

Description of drawings

Fig. 1 is a schematic flow chart of the method of the present invention

Fig. 2 is a schematic diagram of the device network topology of the present invention

Fig. 3 is a schematic view of the overall structure of the device of the present invention (front view)

Fig. 4 is a schematic diagram of the structure of the automatic screening channel for items in the device of the present invention (top view)

The labels in the figure indicate as follows:

1. Rack

2. L-shaped detector frame

3. Detector array collimator

4. Detector array

5. X-ray source

6. Electric drum and conveyor belt

7. X-ray photons

8. Phantom vessel holder for calibration

9. Phantom container for calibration

10. Imitations of prohibited quarantine objects for calibration

11. Item machine screening channel

12. Channel baffle

13. Manual inspection channel

14. Non-contraband channel

15. Moving direction of conveyor belt

Detailed ways

See Figure 1

The method and device for rapid and automatic screening of contraband in quarantine based on X-ray article machines rely on a hybrid topology network. The fast and automatic screening workstations for contraband at each inspection and quarantine port are connected to the data center of the AQSIQ through the optical fiber backbone network bus structure. By comparing the version number information of the quarantine feature database returned from the AQSIQ data center, the latest local quarantine feature database data of the workstation can be updated synchronously according to whether it is necessary. The data download supports training and uploading in the background without affecting the current fast Automatic screening work, when the data download is completed, the version number of the local signature database will be updated and the latest version of the quarantine signature database will be automatically used when the workstation is started next time. The fast automatic screening workstation manages all terminal X-ray item machines in the local area network of the local inspection and quarantine port through a star structure. On the workstation, it can control the startup and shutdown of all terminals, query the status of the terminals and manage them for fast automatic screening and image processing. The module receives and processes the X-ray intensity absorption value of the items in the channel transmitted by each terminal, and after completing the conversion of the outline and feature data of the item, the above data is sent to the workstation, and the workstation sends the outline and feature data of the item sent by the image processing module Compared with the data stored in the local quarantine feature database, the rapid and automatic screening task of the corresponding terminal quarantine contraband can be completed.

See Figure 2

After the staff starts the fast automatic screening workstation and enters the operating system, the workstation will start all terminals in the LAN. After all terminals enter the operating system, the workstation will start the self-check of the terminal hardware equipment and the communication status of the network through the LAN status and command bus. After the test, the initialization of the above workstations and terminals is completed, the system will enter the data synchronization of the workstation quarantine feature database and the update process of the terminal detector response curve, and then work in the state of rapid automatic screening until the staff controls the workstation to end the automatic screening task, the workstation will control all terminals in the LAN to stop automatic screening.

See Figure 3

Update terminal detector response curve: When all terminals in the LAN start up every day, the installed rapid screening application software will perform initial calibration on the respective terminal detector arrays. The initial calibration process includes: offset calibration, dark field calibration and array calibration. Calibration, the above steps measure the dynamic response range of the detector array. After the terminal works continuously for 18 hours, it will prompt to update the detector response curve on the rapid automatic screening application software. Afterwards, the detector response curve can be updated in a timely manner. Under the condition that there are no items in the screening channel, the calibration phantom container embedded with seven equivalent quarantine contraband objects is placed on the fixed frame at a defined position. The seven calibration phantoms in order of X-ray absorption from weak to strong are the equivalent quarantine contraband of milk, soil, apple, egg, ham, cowhide and green beans. After starting the automatic calibration process of the detector response curve on the rapid screening application software, let the terminal equipment collect the intensity absorption value of the equivalent quarantine contraband phantom under X-ray irradiation. Since the diameter of the cylindrical phantom is known, The influence of the light path length on X-ray absorption can be deducted by Lambert-Beer's law, and the corresponding relationship between the types of common quarantine contraband and the X-ray intensity absorption value obtained by the detector can be established, and the consistency of the species response of the detector response curve can be completed. Calibration task. After the update of the terminal detector response curve is completed, the rapid automatic screening application software will no longer prompt to update the detector response curve. The screening application returns to Express Auto Screening.

Fast automatic screening state: When the terminal is working in the fast automatic screening state, when the items to be inspected enter the detection area of the screening channel under the movement of the conveyor belt, the X-ray photon beam emitted by the X-ray tube located in the lower right corner passes through After the inspected item is scanned and received by the detector through the detector array collimator, the X-ray intensity absorption value of the inspected item is obtained, and the relevant data is sent to the image processing module connected to the workstation via the LAN video bus under the control of the workstation. The image processing module will perform the following processing on the X-ray intensity absorption data of the inspected items, including: extracting the shape feature information of all items in the screening channel through frequency domain and spatial filtering, boundary extraction, and morphological reconstruction; through histogram statistics, The X-ray intensity absorption information corresponding to each item is obtained by edge-improved global thresholding. The workstation converts the X-ray intensity absorption information processed by the image processing module into the equivalent density of the substance combined with the outline of the item, and compares it with the local feature database data of the workstation’s quarantine contraband through the table look-up method. When the outline of the item and its When the corresponding equivalent density falls outside the confidence threshold range of the local feature database of quarantine contraband, it means that the item is not a quarantine contraband, and the item will be sent directly to the non-contraband channel; when the outline of the item and its corresponding equivalent density fall below When entering the local feature library of quarantine contraband within the certainty threshold range, an alarm will be triggered immediately to notify the staff next to the manual inspection channel, and the channel baffle will be controlled so that the items are switched to the manual inspection channel for inspection under the movement of the conveyor belt. After the item is checked, the alarm is manually released.

See Figure 4

According to the judgment of the workstation, if the items in the channel are not contraband, the items will be sent out through the non-contraband channel. If the workstation judges that the item is a contraband, it will immediately trigger an alarm, and control the channel baffle in the terminal to change its position. The channel baffle blocks the exit of the non-contraband channel on the left, and the suspected contraband will be sent out through the right hand inspection channel. Quarantine prohibited items that have been hand-checked will be quarantined, destroyed or returned according to regulations. If it is found to be a misjudgment after hand-checking, the items will be released.

Claims (12)

1. A method for fast automatic screening of quarantine contraband based on an X-ray article machine, characterized in that the method comprises the steps: S1: After starting the automatic screening workstation and terminal, check whether the initialization of the workstation and terminal is normal, if not normal, alarm, if normal, execute downward in order; S2: Check whether the quarantine signature database data of the workstation is synchronized. If synchronization is required, the workstation is connected to the AQSIQ data center through the optical fiber backbone network, and the latest quarantine signature database data downloaded is synchronized. If synchronization is not required, it is executed sequentially; S3: Regularly start the task of updating the response curve of the terminal detector. If it needs to be updated, insert the calibration phantom into the terminal to update the segmented fitting response curve of the terminal detector. If it does not need to be updated, execute it in order; S4: Check whether the workstation has received the end screening command. If the command is received, stop the automatic screening of the workstation and terminal real-time online screening task. If the corresponding command is not received, execute it in order; real-time online screening of the terminal Whether the item in the channel is a quarantine prohibited item, if the item is not a prohibited item, it will be executed in order; if the item is judged to be a prohibited item under automatic screening, an alarm will be triggered immediately to notify the staff next to the manual inspection channel, and the conveyor belt movement will Switch the suspected prohibited items in the channel to the manual inspection channel for inspection. If the items are confirmed to be prohibited items after manual inspection by the staff, they will be immediately isolated, destroyed or returned according to the regulations, and executed in sequence; After the manual inspection, it is confirmed that the items are not prohibited items, and the items are released immediately, and executed in sequence. 2. The method for fast and automatic screening of quarantine contraband based on the X-ray article machine as claimed in claim 1, wherein when checking whether the data in the quarantine feature database of the workstation is synchronized, the cluster server of the AQSIQ data center will pass through the optical fiber The backbone network regularly pushes the version number of the quarantine feature database data in the data center to all workstations in the national quality inspection system intranet, and the workstation only needs to compare the latest version number received with its local version number to determine whether the workstation needs to obtain a copy from the national quality inspection system. Download the quarantine signature database on the cluster server of the data center of the General Administration and update the local data. 3. The workstation as claimed in claim 2, characterized in that the workstation is connected to the AQSIQ data center cluster server through the optical fiber backbone network, and is connected to and manages all terminal X-ray item machines in the local inspection and quarantine port LAN through a star LAN. 4. The AQSIQ data center cluster server as claimed in claim 2, characterized in that the AQSIQ will update the quarantine feature library data of its data center in time according to the new quarantine contraband intercepted by inspection and quarantine ports across the country, ensuring Rapid and efficient response to prohibited items by workstations and terminals at inspection and quarantine ports. 5. The method for fast and automatic screening of contraband in quarantine based on the X-ray article machine as claimed in claim 1, characterized in that after using the phantom to update the terminal detector response curve for calibration, all inspection and quarantine ports in the country can be made When the terminal X-ray item machine inspects the same item, it can obtain the same X-ray intensity absorption value of the item on the detector. 6. The method for fast and automatic screening of quarantine contraband based on the X-ray article machine as claimed in claim 1, wherein the workstation can pass through the local area network state when the control terminal automatically checks whether the article in the channel is a quarantine contraband. and the command bus to obtain the status information of the terminal and issue commands, and let the terminal upload the X-ray intensity absorption value of the item scanned to the image processing module connected to the workstation through the LAN video bus. The density data is compared with the local quarantine feature database of the workstation to complete the task of rapid and automatic screening of quarantine contraband. 7. The image processing module as claimed in claim 6, characterized in that the image processing module is common to all terminals in the local area network, and the X-ray intensity absorption value of the item transmitted by the fast processing terminal can be converted into Item outline and equivalent density data. 8. A device for rapid and automatic screening of quarantine contraband based on an X-ray article machine, including (1) frame, (2) L-shaped detector frame, (3) detector array collimator, (4) detection array, (5) X-ray source, (6) electric drum and conveyor belt, (7) X-ray photon, (8) phantom container holder for calibration, (9) phantom container for calibration, (10) calibration Quarantine contraband imitation body, (11) article machine screening channel, (12) channel baffle, (13) hand inspection channel, (14) non-contraband channel and (15) conveyor belt movement direction. 9. The device for fast and automatic screening of quarantine contraband based on the X-ray article machine as claimed in claim 8, characterized in that the focal spot size of the (5) X-ray source is 0.5mm, and the maximum tube voltage is 100kV. The maximum output power is 150W. 10. The device for fast and automatic screening of quarantine contraband based on the X-ray article machine as claimed in claim 8, characterized in that the (4) detector array adopts high and low dual-energy detectors, and its miniature silicon photodiode pixels The size is 0.8mm. 11. The device for fast and automatic screening of quarantine contraband based on the X-ray article machine as claimed in claim 8, characterized in that (9) the phantom container for calibration is placed on (8) the phantom container holder for calibration When the position is limited, the (7) X-ray photons on the line connecting the center point of the (10) quarantine contraband phantom for calibration and the (5) X-ray source will be vertically incident on the (4) detector array. 12. The device for fast and automatic screening of quarantine contraband based on the X-ray article machine as claimed in claim 8, characterized in that (12) the channel baffle can pass through the L-shaped detector array in the channel according to the order of the workstation. Items are sent to non-contraband channels or hand inspection channels.