CN101470082B - Article detection apparatus and detection method thereof - Google Patents

Abstract

The invention discloses an object detection device, which includes an independent DR subsystem and an independent CT subsystem, and also includes a judging device for linking projection data of the DR subsystem and projection data of the CT subsystem for comprehensive judgment. In addition, a detection method is also disclosed, including: using the DR subsystem to obtain the first projection data containing the ray attenuation coefficient information of the A layer of the detected object, and using the CT subsystem to obtain the A layer of the detected object containing the ray attenuation coefficient The second projection data of the information; judging whether there are dangerous goods on the A-level of the detected object according to the first projection data and the second projection data, so as to obtain the first judgment on the A-level of the detected object. Compared with the prior art, the present invention increases the data information for judgment by linking the projection data of the DR subsystem and the projection data of the CT subsystem, so that the judgment result is more accurate without reducing the detected Item pass rate.

Description

Object detection device and detection method thereof

technical field

The invention relates to the technical field of radiation detection, in particular to an item detection device for safely detecting dangerous items such as explosives and drugs in a suitcase and a detection method for the item detection device.

Background technique

In recent years, more and more attention has been paid to the method and equipment of CT technology applied to the detection of explosives. Especially after the 9.11 incident, it is particularly important to check the luggage items carried by passengers in the aviation security work.

Currently, ray-type equipment used for package inspection is mainly divided into two categories: DR and CT.

DR-type radiation detection equipment adopts traditional two-dimensional digital imaging technology. Its advantage is that the detection speed is fast, the baggage passing rate is high, and it is easy to judge dangerous goods such as metals; the disadvantage is that the amount of information obtained by the detector is small, and it is difficult to accurately judge explosives, so it is more suitable for forming a planar image.

CT-type ray detection equipment mainly uses CT reconstruction algorithm to reconstruct the tomographic image of luggage. The advantage is that the tomographic data is rich in information, and explosives can be accurately judged by reconstructing the tomographic image; the disadvantage is that the detection speed is slow and the luggage passing rate is low.

Due to the deficiencies of the above two types of luggage safety testing equipment, it is difficult to meet the requirements of high pass rate and high accuracy at the same time, because, with the development of science and technology, not only requires a higher speed of luggage inspection, but also requires the equipment to be able to Accurately identify dangerous goods.

Therefore, recently, a multi-level scanning mode line packet detection device is proposed, which jointly applies a DR device and a CT device. The luggage detection equipment in the multi-level scanning mode first uses DR detection to pre-judge the danger of the luggage, and then performs CT detection on the suspected area. The advantage of this kind of equipment is that the detection speed is high, but the pre-judgment accuracy is not high, misjudgment is prone to occur, and the equipment is relatively large.

Contents of the invention

Therefore, the present invention aims to provide an object detection device with high detection speed and high judgment accuracy and a detection method thereof.

In order to achieve the above object, the present invention provides a detection method of an item detection device, the item detection device includes an independent DR subsystem and an independent CT subsystem, the detection method includes the following steps: using the DR subsystem to obtain the detected object The first projection data of the A level of the detected object is obtained by using the CT subsystem to obtain the second projection data of the A level of the detected object, wherein the projection angle for obtaining the first projection data is different from the projection angle for obtaining the second projection data; according to the first projection The data and the second projection data are used to determine whether there are dangerous goods on the A-level of the detected item, so as to obtain the first judgment on the A-level of the detected item.

In addition, the present invention also provides an object detection device, which includes an independent DR subsystem and an independent CT subsystem, wherein the object detection device further includes linking the projection data of the DR subsystem and the projection data of the CT subsystem in A judging device that makes comprehensive judgments together.

Compared with the prior art, the present invention increases the data information for judgment by linking the projection data of the DR subsystem and the projection data of the CT subsystem, so that the judgment result is more accurate without reducing the detected Item pass rate.

Description of drawings

Fig. 1 is the object detection device of the present invention;

Fig. 2 is a schematic diagram of layer A of the detected article of the present invention;

Fig. 3 shows a schematic diagram of projecting layer A of the detected article of the present invention at different projection angles;

FIG. 4 is a diagram showing a group of slices centered on slice A.

Detailed ways

【The first embodiment】

The first embodiment mainly describes the structure and features of the object detection device.

Fig. 1 shows the object detection device of the present invention. The object detection device shown in FIG. 1 includes an independent DR subsystem 2 and an independent CT subsystem 3 . The DR subsystem 2 has a radiation source 5 and a detector 6 . The CT subsystem 3 has a radiation source 7 , a detector 8 and a slip ring 9 . Since the specific configurations of the DR subsystem 2 and the CT subsystem 3 belong to the prior art, they will not be described in detail. The object detection device shown in FIG. 1 also includes a judging device 4, which communicates with the detector 6 of the DR subsystem 2 and the detector 8 of the CT subsystem 3 respectively, and is used to obtain projection data of the DR subsystem respectively. and the projection data of the CT subsystem, and link the projection data of the DR subsystem with the projection data of the CT subsystem for comprehensive judgment.

In the prior art, the judgment is generally made only based on the projection data of the DR subsystem or only based on the projection data of the CT subsystem, so the amount of data information used for the judgment is small, resulting in low judgment accuracy. However, the judging device of the present invention links the projection data of the DR subsystem and the projection data of the CT subsystem together for comprehensive judgment, thereby increasing the amount of data information used for judgment and improving the accuracy of judgment.

As shown in Figure 1, the detected item 1 is placed on the conveyor belt, and undergoes DR scanning and CT scanning respectively. Figure 2 shows a layer A of the detected object 1. When the layer A passes through the DR subsystem 2, the DR subsystem will project the layer A along a fixed projection angle α (see Figure 3), so that the detected object can be obtained For the distribution of the ray attenuation coefficient of the layer A, the distribution of the ray attenuation coefficient obtained by using DR may be called the first projection data of the ray attenuation coefficient. When the layer A of the object 1 to be detected passes through the CT subsystem 3, since the ray source 7 and the detector 8 of the CT subsystem rotate with the slip ring 9, the CT subsystem will reassess the layer A along another projection angle β. projection (see FIG. 3 ), so that the distribution of the ray attenuation coefficient of the layer A of the detected object can be obtained again. The distribution of the ray attenuation coefficient obtained by CT may be called the second projection data of the ray attenuation coefficient.

Since the CT subsystem and the DR subsystem respectively project the same layer A of the detected object at different projection angles, two sets of projection data can be obtained for the same layer A, which doubles the amount of projection data of the same layer A. This will undoubtedly help to improve the accuracy of judgment.

Further, as shown in FIG. 4, when the slip ring 9 of the CT subsystem rotates and scans, it is also possible to obtain the projection data of all layers in the front and rear intervals centered on the A layer, that is, as shown in FIG. 4, Projection data from the Af plane to the Ab plane can be acquired. In FIG. 4 , plane A is the central plane between plane Af and plane Ab, that is, the distance from plane Af to plane A is equal to the distance from plane A to plane Ab. Further, if the detector 8 of the CT subsystem adopts high and low energy detectors, the CT subsystem can also obtain the dual-energy projection data from the Af layer to the Ab layer of the detected object, and reconstruct and obtain the effective atomic number distribution on the A layer .

【Second Embodiment】

The second embodiment of the present invention is mainly based on the above characteristics of the item detection device, and proposes the first detection method of the item detection device. The item detection device includes an independent DR subsystem and an independent CT subsystem. The detection method includes the following Step: use the DR subsystem to obtain the first projection data containing the ray attenuation coefficient information of the A layer of the detected object, and use the CT subsystem to obtain the second projection data containing the ray attenuation coefficient information of the A layer of the detected object, wherein The projection angle of the first projection data is different from the projection angle of the second projection data; according to the first projection data and the second projection data, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the A layer of the detected object first judgment.

The above-mentioned first judgment is obtained based on two sets of projection data of the same layer A, so the amount of data information of the layer A is increased, and the judgment accuracy is improved. Please note that the first judgment of the present invention is a comprehensive judgment that links the projection data of the DR subsystem and the projection data of the CT subsystem.

[Third embodiment]

The third embodiment of the present invention mainly proposes the detection method of the second object detection device, and the second detection method also includes the steps:

The DR subsystem is used to obtain the first projection data containing the ray attenuation coefficient information of the A layer of the detected object, and the CT subsystem is used to obtain the second projection data containing the ray attenuation coefficient information of the A layer of the detected object, wherein the first The projection angle of the projection data is different from the projection angle of the second projection data; according to the first projection data and the second projection data, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the first A layer of the detected object a judgment;

Use the CT subsystem to obtain the projection data from the Af level to the Ab level of the detected object, where the A level is the central level between the Af level and the Ab level, that is, the distance from the Af level to the A level is equal to the A level to the Ab level The distance of the layer; the CT algorithm reconstruction is performed on the tomographic projection data of the ray attenuation coefficient, and according to the reconstruction result, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the second judgment on the A layer of the detected object;

Combining the first judgment and the second judgment, the final judgment of whether there are dangerous goods on the A layer of the detected item is obtained.

The above-mentioned second judgment is obtained based on the projection data of the ray attenuation coefficients of all slices in the intervals before and after slice A, thus increasing the amount of data information of slice A and improving the judgment accuracy. Please note that the CT algorithm used in the second judgment may be any algorithm in the prior art.

The above-mentioned final judgment is another comprehensive judgment obtained based on the first judgment and the second judgment, which has a larger amount of data information and higher judgment accuracy.

[Fourth Embodiment]

The fourth embodiment of the present invention mainly proposes the detection method of the third object detection device, the detection method includes steps:

The DR subsystem is used to obtain the first projection data containing the ray attenuation coefficient information of the A layer of the detected object, and the CT subsystem is used to obtain the second projection data containing the ray attenuation coefficient information of the A layer of the detected object, wherein the first The projection angle of the projection data is different from the projection angle of the second projection data; according to the first projection data and the second projection data, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the first A layer of the detected object a judgment;

Use the CT subsystem to obtain the projection data from the Af level to the Ab level of the detected object, where the A level is the central level between the Af level and the Ab level, that is, the distance from the Af level to the A level is equal to the A level to the Ab level The distance of the layer; the CT algorithm reconstruction is performed on the above projection data, and according to the distribution of the ray attenuation coefficient in the reconstruction result, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the second judgment on the A layer of the detected object;

Use the CT subsystem to obtain the projection data from the Af level to the Ab level of the detected item; perform CT algorithm reconstruction to obtain the effective atomic number distribution of the A level, and judge whether there are dangerous goods in the A level of the detected item according to this distribution, thereby Obtain a third judgment on the A-level of the detected item;

Combining the first judgment, the second judgment and the third judgment, the final judgment of whether there are dangerous goods in the A layer of the detected item is obtained.

The above-mentioned third judgment is also obtained based on the projection data of all layers in the interval before and after the layer A, so the amount of data information of the layer A is also increased, and the judgment accuracy is improved. Please note that the CT algorithm used in the third determination may be any algorithm in the prior art.

[fifth embodiment]

The fifth embodiment of the present invention mainly proposes the detection method of the fourth article detection device, and the detection method includes steps:

The DR subsystem is used to obtain the first projection data containing the ray attenuation coefficient information of the A layer of the detected object, and the CT subsystem is used to obtain the second projection data containing the ray attenuation coefficient information of the A layer of the detected object, wherein the first The projection angle of the projection data is different from the projection angle of the second projection data; according to the first projection data and the second projection data, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the first A layer of the detected object a judgment;

Use the CT subsystem to obtain the projection data from the Af level to the Ab level of the detected object, where the A level is the central level between the Af level and the Ab level, that is, the distance from the Af level to the A level is equal to the A level to the Ab level The distance of the level; perform CT algorithm reconstruction on the above projection data, and judge whether there are dangerous goods on the A level of the detected item according to the reconstruction result, so as to obtain the second judgment on the A level of the detected item;

The DR subsystem is used to obtain the projection data of all levels of the detected item, so as to obtain the two-dimensional projection map of the detected item, and judge whether there are dangerous goods on the A layer of the detected item according to the two-dimensional projection map, so as to obtain information about the detected item The fourth judgment of the A level of the item;

Combining the first judgment, the second judgment and the fourth judgment, the final judgment of whether there are dangerous goods in the A layer of the detected item is obtained.

The fourth judgment above is based on the two-dimensional projection image of the detected object, so the amount of data is large and the judgment accuracy is high.

[Sixth embodiment]

The sixth embodiment of the present invention mainly proposes a detection method of a fifth object detection device, which detection method includes steps:

The DR subsystem is used to obtain the first projection data containing the ray attenuation coefficient information of the A layer of the detected object, and the CT subsystem is used to obtain the second projection data containing the ray attenuation coefficient information of the A layer of the detected object, wherein the first The projection angle of the projection data is different from the projection angle of the second projection data; according to the first projection data and the second projection data, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the first A layer of the detected object a judgment;

Use the CT subsystem to obtain the projection data from the Af level to the Ab level of the detected object, where the A level is the central level between the Af level and the Ab level, that is, the distance from the Af level to the A level is equal to the A level to the Ab level The distance of the layer; the above projection data is reconstructed by CT algorithm, and according to the distribution of ray attenuation information in the reconstruction result, it is judged whether there are dangerous goods on the A layer of the detected object, so as to obtain the second judgment on the A layer of the detected object;

Use the CT subsystem to obtain the projection data from the Af level to the Ab level of the detected item; perform CT algorithm reconstruction on the above projection data, and judge whether there are dangerous goods in the A level of the detected item according to the effective atomic number distribution in the reconstruction result, Thereby obtaining the third judgment about the A level of the detected item;

The DR subsystem is used to obtain the projection data of all levels of the detected item, so as to obtain the two-dimensional projection map of the detected item, and judge whether there are dangerous goods on the A layer of the detected item according to the two-dimensional projection map, so as to obtain information about the detected item The fourth judgment of the A level of the item;

Combining the first judgment, the second judgment, the third judgment and the fourth judgment, the final judgment of whether there are dangerous goods in the A layer of the detected object is obtained.

【Other possible changes】

According to the descriptions of the above embodiments, it can be seen that Embodiments 2 to 5 of the present invention disclose five detection methods respectively: the first detection method including only the first judgment; the second detection method including the first judgment and the second judgment ; A third detection method including the first judgment, the second judgment and the third judgment; A fourth detection method including the first judgment, the second judgment and the fourth judgment; Judgment and fourth judgment of the fifth detection method.

Obviously, according to the reasoning above, the detection method of the present invention can also be: the sixth detection method comprising the first judgment and the third judgment; the seventh detection method comprising the first judgment and the fourth judgment; including the first judgment , The eighth detection method of the third judgment and the fourth judgment. These changes are obvious to those skilled in the art.

In the above embodiments, both the DR subsystem and the CT subsystem can use high and low energy detectors, so that the comprehensive application of dual-energy DR and CT technologies can be realized.

While embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by The appended claims and their equivalents are defined.

Claims (10)

1. a detection method of article detection device, this article detection device comprises independent DR subsystem and independent CT subsystem, and described detection method comprises the steps: Use the DR subsystem to obtain the first projection data of the ray attenuation coefficient of the A layer of the detected object, and use the CT subsystem to obtain the second projection data of the ray attenuation coefficient of the A layer of the detected object, wherein the projection of the first projection data is obtained the angle is different from the projection angle from which the second projection data was obtained; According to the first projection data and the second projection data, it is judged whether there are dangerous goods on the A-level of the detected item, so as to obtain a first judgment on the A-level of the detected item. 2. detection method as claimed in claim 1, also comprises step: Use the CT subsystem to obtain the projection data from the Af level to the Ab level of the detected object, where the A level is the central level between the Af level and the Ab level, that is, the distance from the Af level to the A level is equal to the A level to the Ab level level distance; Perform CT algorithm reconstruction on the projection data, and judge whether there are dangerous goods on the A-level of the detected item according to the reconstruction result, so as to obtain the second judgment on the A-level of the detected item. 3. detection method as claimed in claim 2, also comprises step: Combining the first judgment and the second judgment, the final judgment of whether there are dangerous goods on the A layer of the detected item is obtained. 4. detection method as claimed in claim 2, wherein CT subsystem adopts high and low energy detector, described detection method also comprises the step: Use the CT subsystem to obtain dual-energy projection data from the Af level to the Ab level of the detected item; Perform CT algorithm reconstruction on the dual-energy projection data, and obtain the effective atomic number distribution based on the reconstruction results to judge whether there are dangerous goods on the A-level of the detected item, so as to obtain the third judgment on the A-level of the detected item. 5. detection method as claimed in claim 4, also comprises the step: Combining the first judgment, the second judgment and the third judgment, the final judgment of whether there are dangerous goods in the A layer of the detected item is obtained. 6. detection method as claimed in claim 2, also comprises the step: Use the DR subsystem to obtain the projection data of all layers of the detected object, thereby obtaining the two-dimensional projection map of the detected object, and judge whether there are dangerous goods on the A layer of the detected object according to the two-dimensional projection map, so as to obtain information about the detected object The fourth judgment of the A level of the item. 7. detection method as claimed in claim 6, also comprises the step: Combining the first judgment, the second judgment and the fourth judgment, the final judgment of whether there are dangerous goods in the A layer of the detected item is obtained. 8. detection method as claimed in claim 4, also comprises the step: The DR subsystem is used to obtain the projection data of all levels of the detected item, so as to obtain the two-dimensional projection map of the detected item, and judge whether there are dangerous goods on the A layer of the detected item according to the two-dimensional projection map, so as to obtain information about the detected item The fourth judgment of the A level of the item. 9. detection method as claimed in claim 8, also comprises the step: Combining the first judgment, the second judgment, the third judgment and the fourth judgment, the final judgment of whether there are dangerous goods in the A layer of the detected object is obtained. 10. The detection method according to any one of the preceding claims, wherein the DR subsystem uses high and low energy detectors.

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