CN102162798B - Method and equipment for inspecting liquid article - Google Patents

Abstract

The invention discloses a method and equipment for inspecting a liquid article by dual-energy helical computed tomography (CT). The method comprises the following steps of: emitting high-energy and low-energy X rays by a ray source; detecting and acquiring the high-energy and low-energy X rays penetrating at least one liquid article to be inspected; carrying the liquid article to be inspected to ensure it can rotate around an axis and can be lifted, so that the liquid article to be inspected enters a detection region, and the high-energy and low-energy X rays emitted by the ray source can penetrate the liquid article to be inspected; performing dual-energy helical CT scanning on the liquid article to be inspected to form a group of helical CT images, each of which represents at least one physical attribute value of the liquid article to be inspected; analyzing the group of helical CT images to determine a helical CT image part of the liquid; and judging whether the liquid article is a dangerous article based on the physical attribute values and reference physical attribute values of the liquid article. By the invention, the liquid article can be quickly inspected.

Description

Liquid article examination method and equipment

The application submits to the dividing an application of No. 200710180652.8 application for a patent for invention that is entitled as " liquid article examination method and equipment " of Patent Office of the People's Republic of China on October 5th, 2007.

Technical field

The present invention relates to the radiation monitoring technical field, particularly a kind ofly by the liquid towards article, carry out the method and apparatus that dual intensity CT imaging comes the liquid towards article fast and safely to check.

Background technology

After 911 events of the U.S. occur, the safety inspection work of aviation field more and more comes into one's own.On the basis of the luggage parcel safety inspection of in the past carrying out, increased the safety inspection requirement of the liquid article that the passenger is carried.Therefore, be badly in need of the fast and safely inspection that effective mode and means are carried out liquid article in luggage and articles.

Current, have the method for following four classes can be for the safety inspection of liquid article: chemical method, electromagnetic method, submethod and ray method specifically describe as follows:

1) chemical method can be subdivided into odor identification, ion scan is surveyed and species analysis.Odor identification usually can't be realized because of the sealed packing of liquid article checking in actual applications.Ion scan is surveyed famous with hypersensitivity, but its shortcoming is that rate of false alarm is high, usually is subject to the impact of background environment.Species analysis has precision height and the high characteristics of accuracy, but this method needs the regular hour to be analyzed sample, can not meet the on-the-spot demand checked fast.

2) metering system that electromagnetic method is taken the initiative, thus it makes a distinction liquid article to electromagnetic specific inductive capacity is different according to different liquid articles.Electromagnetic method itself easily is subject to the adverse effect of mental package and thicker material packing.Therefore, under the actual conditions of wrappage complexity, electromagnetic method has certain limitation.

3) use of neutron inspection method there will be the phenomenon of " neutron activation ", and the liquid article that is examined through the neutron inspection has the radiation residual phenomena.And, because the penetration capacity of neutron is stronger, therefore its radiation shield is more complicated, occupation area of equipment is large, thereby be not suitable for using in the safety check system of civil aviaton.

4) current, the safety inspection device of aviation field mostly is x-ray apparatus, and in these devices, adopting at present maximum technology is X ray two-dimensional imaging technology and three-D CT scanning imaging technique.These technology are mainly used in luggage and articles are carried out to safety inspection, can not carry out safety inspection for the liquid article in luggage and articles specially.

X ray two-dimensional imaging technology is the three-dimensional information of inspected object to be obtained to the two-dimensional signal projected image of object in X-ray beam direction upper integral.These images adopt the form of expression of gray scale or pseudo-colours to show the structure of interior of articles, give the equipment operator to show intuitively.Therefore but X ray two-dimensional imaging technology has lacked the information of a dimension of inspected object after all, check the especially severe that affects of the profile that is subject to being examined liquid article and size with these technology liquid towards article.

The three-D CT scanning imaging technique is the promotion and application of CT technology.The CT technology is applied to medical science the earliest, is the instrument that auxiliary doctor is diagnosed.It is that the projection of carrying out multi-angle by each tomography to checked property realizes.Reconstruction by computing machine to the multi-angle projection data of above-mentioned each tomography, calculate the reconstructed image of each tomography, with different gray scales, shows different attenuation coefficient information in reconstructed image, thereby show the inner structure of checked property.Development along with the CT technology, occurred for the industry CT of nondestructive examination with for luggage CT of safety inspection etc., it is purpose that these CT Extended Technologies remain to obtain the faultage image that shows internal structure of body, depend on manually structure is analyzed, to judge whether checking matter belongs to dangerous goods, be not suitable for automatically, check fast.In addition, above-mentioned CT type Security Inspection Equipments, because its checked property scope covered is wide, and cause cost high, and the equipment heaviness, apply difficulty.

In sum, for liquid article, check fast, chemical method, electromagnetic method and middle submethod exist the characteristics that itself are not suitable for fast and safely checking, adopt X ray two-dimensional imaging technology and three-D CT scanning imaging technique, can only obtain the image of performance article inner structure, can not provide abundant foundation for automatic, the safety inspection of liquid article.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the purpose of this invention is to provide a kind of method and apparatus with safety-checking liquid stage article with ray, it can in the situation that do not destroy liquid article packing it is checked fast, obtain being examined the quantitative information of liquid article.

In one aspect of the invention, provide a kind of equipment checked with dual intensity spiral CT liquid towards article, having comprised: radiographic source, for sending high energy and low energy X ray; Survey and harvester, for surveying and gather high energy and the low energy X ray that penetrates at least one tested liquid article; Load carrier, carry tested liquid article and rotate around axle, and can lifting, make tested liquid article enter surveyed area, thereby the high energy sent by radiographic source and low energy ray can see through tested liquid article; Controller, control described radiographic source and detection and harvester tested liquid article carried out to the dual intensity Spiral CT scan, forms one group of spiral CT image of each at least one physical property values that all means tested liquid article; Computing machine, analyze this group spiral CT image to determine the spiral CT image section of liquid, and the physical property values comprised in the spiral CT image section based on liquid judges in Zhong De position, the space of respective dimensions whether described tested liquid article is dangerous material.

According to embodiments of the invention, described physical property values at least comprises density and the atomic number of tested liquid article.

According to embodiments of the invention, described dual intensity Spiral CT scan is the screw with long screw pitch CT scan.

According to embodiments of the invention, whether the described physical property values that judges described computing machine drops on by the described preset range limited with reference to physical property values, and the described liquid article that judges of the situation in described physical property values drops on described preset range is dangerous material.

According to embodiments of the invention, described controller comprises: control module, control radiographic source, load carrier and detection and harvester according to the instruction from computing machine; The trigger pip generation unit produces the trigger command of the action be used for triggering radiographic source, detection and harvester and load carrier under the control of control module; The first drive motor, the trigger command produced under the control at control module according to the trigger pip generation unit drives load carrier to rise or descends; The elevation information acquiring unit, along with the motion of load carrier, to the elevation information of control module feedback load carrier; The second drive motor, the trigger command produced under the control at control module according to the trigger pip generation unit drives the load carrier rotation; The angle information acquiring unit obtains the anglec of rotation of load carrier in the load carrier rotary course, feeds back to control module.

According to embodiments of the invention, described elevation information acquiring unit and angle information acquiring unit are all photoelectric code disks.

In another aspect of this invention, provide a kind of method checked with dual intensity spiral CT liquid towards article, having comprised: from radiographic source, send high energy and low energy X ray; Survey and gather the high energy and the low energy X ray that penetrate at least one tested liquid article; Carry tested liquid article and rotate around axle, and can lifting, make tested liquid article enter surveyed area, thereby the high energy sent by radiographic source and low energy ray can see through tested liquid article; Tested liquid article is carried out to the dual intensity Spiral CT scan, form one group of spiral CT image of each at least one physical property values that all means tested liquid article; Analyze this group spiral CT image to determine the spiral CT image section of liquid; And the reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is dangerous material.

According to embodiments of the invention, described physical property values at least comprises density and the atomic number of tested liquid article.

According to embodiments of the invention, described dual intensity Spiral CT scan is the screw with long screw pitch CT scan.

According to embodiments of the invention, the reference physical property values based on described physical property values and this liquid article judges that whether described tested liquid article is that the step of dangerous material comprises: judge whether described physical property values drops on by the described preset range limited with reference to physical property values; And the described liquid article that judges of the situation in described physical property values drops on described preset range is dangerous material.

In one aspect of the invention, propose a kind of method checked with dual intensity CT liquid towards article, comprised step: tested liquid article is carried out to the dual intensity CT scan, obtain dual intensity CT data for projection; Carry out the CT reconstruction according to described data for projection, obtain meaning the CT image of the physical property values of tested liquid article; Extract the physical property values of tested liquid article according to described CT image; And judge based on described physical property values whether described tested liquid article is dangerous material.

According to embodiments of the invention, described physical property values comprises density and the atomic number of tested liquid article.

According to embodiments of the invention, described dual intensity CT scan adopts the mode of plane fault CT scan.

According to embodiments of the invention, described dual intensity CT scan adopts the mode of conventional Spiral CT scan.

According to embodiments of the invention, described dual intensity CT scan adopts the mode of screw with long screw pitch CT scan.

According to embodiments of the invention, before carrying out the plane fault CT scan, preset one group of scanning position.

According to embodiments of the invention, before carrying out the plane fault CT scan, first carry out the transmission image that DR scanning obtains inspected object, then according to transmission image, determine the CT scan position.

According to embodiments of the invention, after obtaining transmission image, the operator specifies at least a line in transmission image by input media, as the CT scan position.

According to embodiments of the invention, after obtaining transmission image, automatically determine at least a line in transmission image by image processing techniques, as the CT scan position.

According to embodiments of the invention, the step that forms transmission image comprises: send high-energy ray and low energy ray from radiographic source, penetrate tested object, form high energy transmission image and low energy transmission image; Merge high energy transmission image and low energy transmission image, form described transmission image.

According to embodiments of the invention, the step that forms transmission image comprises: send high-energy ray and low energy ray from radiographic source, penetrate tested object, form high energy transmission image and low energy transmission image; Select one of high energy transmission image and low energy transmission image, as described transmission image.

According to embodiments of the invention, the step of rebuilding the CT image of the physical property values that means tested liquid article from the dual intensity data for projection comprises: according to high low energy data for projection, generate the data for projection about two kinds of sill coefficients; Rebuild according to the data for projection of described two kinds of sill coefficients, obtained meaning the CT image of the corresponding two kinds of sill coefficients of tested liquid; And, according to described expression sill coefficient CT image, generate the CT image of the tested liquid article physical property values of described expression.

According to embodiments of the invention, according to the CT image of the physical property values that means tested liquid article, the step that obtains tested liquid article physical property values comprises: extract the pixel corresponding with the liquid part from described CT image; To pixel bulk density average and the atomic number average of liquid part, as density and the atomic number of described tested liquid article.

According to embodiments of the invention, judge that based on described physical property values whether described tested liquid article is that the step of dangerous material comprises: judge whether the determined point of described density and atomic number drops in the presumptive area in density-atomic number two-dimensional coordinate space; In the situation that, during described point drops on described presumptive area, think that described tested liquid article is dangerous material.

According to embodiments of the invention, after for each position, carrying out the dual intensity CT scan, rotation is examined the CT image of liquid article, makes itself and the formed image alignment of dual intensity CT scan for the first time.

According to embodiments of the invention, after for each row, carrying out the dual intensity CT scan, rotate tested liquid article, make it identical with the position before scanning.

According to embodiments of the invention, described liquid article is placed in the bucket that has been divided into a plurality of spaces.

According to embodiments of the invention, described method also comprises step: utilize predetermined template automatically to detect the existence of bucket; In the situation that there is bucket, detect the specific markers in the CT image; Based on described specific markers, bucket is rotated to preposition.

According to embodiments of the invention, described method also comprises step: by the judgment result displays of tested liquid article on display screen.

According to embodiments of the invention, described method also comprises step: the judged result of each tested liquid article is printed.

According to embodiments of the invention, described method also comprises step: by the CT image color of each tested liquid article.

According to embodiments of the invention, described dual intensity CT scan is based on preposition and carries out.

In another aspect of this invention, proposed a kind of equipment checked with dual intensity CT liquid towards article, having comprised: radiographic source, for sending ray; Survey and harvester, for surveying and gather the ray signal that penetrates at least one tested liquid article; Controller, control described radiographic source and detection and harvester tested liquid article carried out to the dual intensity CT scan, obtains data for projection; Rebuild the device of the CT image of at least one physical property values that means tested liquid article from data for projection; And judge in Zhong De position, the space of respective dimensions based on described physical property values whether described tested liquid article is the device of dangerous material.

According to embodiments of the invention, described dual intensity CT scan is based on preposition and carries out.

According to embodiments of the invention, the ray signal that penetrates at least one tested liquid article is surveyed and gathered to described detection and harvester to form transmission image; Wherein said equipment also comprises the device of specifying at least a line in transmission image; Described dual intensity CT scan is based on specified going and carries out.

According to embodiments of the invention, described in physical property values at least comprise density and the atomic number of tested liquid article.

According to embodiments of the invention, send high-energy ray and low energy ray from radiographic source, penetrate tested object, form high energy transmission image and low energy transmission image, described equipment also comprises: merge the device that high energy transmission image and low energy transmission image form described transmission image.

According to embodiments of the invention, send high-energy ray and low energy ray from radiographic source, penetrate tested object, form high energy transmission image and low energy transmission image, described equipment also comprises: select one of high energy transmission image and low energy transmission image, as the device of described transmission image.

According to embodiments of the invention, the device of at least a line in described appointment transmission image comprises: the operator utilizes input media to select at least device of a line from transmission image.

According to embodiments of the invention, the device of at least a line in described appointment transmission image comprises: analyze the pixel value of described transmission image, with the device by described transmission image layering; Middle row in each layer is appointed as to the device that will carry out the row of dual intensity CT scan.

According to embodiments of the invention, rebuild to mean that from data for projection the device of CT image of the physical property values of tested liquid article comprises: merge density image that the density by tested liquid article identifies and the atomic number image that identified by the atomic number of tested liquid article as the device of described CT image; Extract the pixel corresponding with the liquid part from described CT image; To the pixel bulk density average of liquid part and atomic number average as the density of described tested liquid article and the device of atomic number.

According to embodiments of the invention, judge that based on described physical property values whether described tested liquid article is that the device of dangerous material comprises: judge whether the determined point of described density and atomic number drops on the device in the presumptive area in density-atomic number two-dimensional coordinate space, wherein, in the situation that, during described point drops on presumptive area, think that described tested liquid article is dangerous material.

According to embodiments of the invention, described equipment also comprises: after for every row, carrying out the dual intensity CT scan, rotation is examined the CT image of liquid article, makes itself and the device of the formed image alignment of dual intensity CT scan for the first time.

According to embodiments of the invention, described equipment rotates tested liquid article after also being included in and carrying out the dual intensity CT scan for each row, makes its device identical with the position before scanning.

According to embodiments of the invention, described equipment also comprises bucket, has been divided into a plurality of spaces, is respectively used to place described liquid article.

According to embodiments of the invention, described equipment also comprises: utilize predetermined template automatically to detect the device of the existence of bucket; In the situation that there is bucket, detect the device of the specific markers in the CT image; Based on described specific markers, bucket is rotated to the device of preposition.

According to embodiments of the invention, described equipment also comprises: display device shows the judged result of tested liquid article.

According to embodiments of the invention, described equipment also comprises: the device that the judged result of each tested liquid article is printed.

According to embodiments of the invention, described equipment also comprises: by the device of the CT image color of each tested liquid article.

According to embodiments of the invention, described equipment also comprises the load carrier that carries described tested liquid article, on the surface of the described tested liquid article of described bearing structure carrying, is divided into the discernible a plurality of zones of operating personnel.

In still another aspect of the invention, proposed a kind of equipment checked with dual intensity CT liquid towards article, having comprised: radiographic source, for sending ray; Survey and harvester, for surveying and gather the ray signal that penetrates at least one tested object; Controller, control described radiographic source and detection and harvester tested liquid article carried out to Spiral CT scan, forms one group of spiral CT image of each at least one physical property values that all means tested liquid article; Analyze the device of this group spiral CT image with the spiral CT image section of determining liquid; And the physical property values comprised in the spiral CT image section based on liquid judges in Zhong De position, the space of respective dimensions whether described tested liquid article is the device of dangerous material.

Utilize method and apparatus of the present invention, owing to adopting transmission image to carry out the dual intensity CT scan as guiding, when having improved detection speed, do not reduce Detection accuracy, and can also judge by transmission image whether liquid article exists interlayer.

In addition, whether the density of measuring by judgement and atomic number drop in the presumptive area of two-dimensional space, can judge whether tested liquid article is explosive.

In addition, the operator can carry out the dual intensity CT scan in the position of any appointment, has facilitated the carrying out of check operation.

In addition, in the situation that many detections simultaneously adopt the lattice bucket, can determine easily it is whether the tested liquid article of that part is explosive.

The accompanying drawing explanation

From the detailed description below in conjunction with accompanying drawing, above-mentioned feature and advantage of the present invention will be more obvious, wherein:

Fig. 1 is the structural representation according to the checkout facility of embodiment of the present invention;

Fig. 2 shows the structured flowchart of computer data processor 60 as shown in Figure 1;

Fig. 3 shows the structured flowchart according to the controller of first embodiment of the invention;

Fig. 4 A and 4B show the schematic diagram according to the method for inspection liquid article of the present invention;

Fig. 5 is the schematic diagram of the relation for DR imaging and CT imaging are described;

Fig. 6 shows an example of DR imaging results;

Fig. 7 shows another example of DR imaging results;

Fig. 8 shows the overview flow chart according to the liquid article examination method of first embodiment of the invention;

Fig. 9 shows the process flow diagram of DR imaging process;

Figure 10 shows in the DR imaging process and to survey and the arrangement mode of the DR view data that harvester 30 gathers;

Figure 11 shows the process flow diagram of the DR image being processed to determine the CT scan position;

Figure 12 shows the CT imaging process;

Figure 13 shows the arrangement mode of CT data for projection in the CT imaging process;

Figure 14 shows the process of measuring the liquid attribute;

Figure 15 A and Figure 15 B show the schematic diagram of the CT image of rebuilding in the situation according to many liquid articles of detection of second embodiment of the invention;

Figure 16 A shows after the CT imaging completes to 16K, how CT reconstructed image and/or load carrier is rotated to its process consistent with the relative position of object before CT scan that make;

Figure 17 shows in the situation that many process flow diagrams that tested object is checked;

Figure 18 shows the vertical view according to the load carrier of second embodiment of the invention;

Figure 19 shows the side view according to the lattice bucket of present embodiment;

Figure 20 shows the vertical view of lattice bucket;

Figure 21 shows the backplan of lattice bucket;

Figure 22 shows the process that how automatically to detect lattice bucket and mark in checking process;

Figure 23 A shows the schematic diagram of rotary barrel in testing process to 23D;

Figure 24 shows the process flow diagram according to the checking process of the 3rd embodiment;

Figure 25 is the schematic diagram that explanation liquid towards article carry out Spiral CT scan;

Figure 26 A is that explanation liquid towards article carry out the resulting image of Spiral CT scan to 26M.

Embodiment

Below, describe the preferred embodiment of the present invention in detail with reference to accompanying drawing.In the accompanying drawings, although be shown in different accompanying drawings, identical Reference numeral is for meaning identical or similar assembly.For clarity and conciseness, the detailed description that is included in the known function and structure here will be omitted, otherwise they will make theme of the present invention unclear.

[the first embodiment]

Fig. 1 is the structural representation according to the checkout facility of embodiment of the present invention.

As shown in Figure 1, according to the checkout facility of present embodiment, comprise: send the radiographic source 10 checked with dual-energy x-ray, such as X-ray machine; Load carrier 40, it carries tested liquid article and rotates around axle Z, and can lifting, make tested liquid article enter surveyed area, thereby the ray sent by radiographic source 10 can see through tested liquid article; Survey and harvester 30, it is detector and the data acquisition unit with integral module structure, for surveying the dual intensity ray of the tested liquid article of transmission, obtain simulating signal, and analog signal conversion is become to digital signal, thereby the dispensing liquid article are for the scan-data of sigmatron and low energy X ray; Controller 50, it is for controlling the various piece synchronous working of whole system; And computer data processor 60, it is used for processing the data that gathered by data acquisition unit, and the outgoing inspection result.

As shown in Figure 1, radiographic source 10 is placed in load carrier 40 1 sides that can place tested liquid article, detection and harvester 30 are placed in the opposite side of load carrier 40, comprise detector and data acquisition unit, for obtaining tested liquid article DR data and multi-angle projection data.Data acquisition unit comprises data amplification wave-shaping circuit, and it can work in (electric current) integral way or pulse (counting) mode.Survey and be connected with computer data processor 60 with the data output cable of harvester 30, according to trigger command, the data of collection are stored in computer data processor 60.

In addition, checkout facility also comprises the tubular object passage 20 be made of metal, and it is arranged on load carrier 40, can shield the outside radiation of X ray.Tested liquid article is placed in tested object passage.

Fig. 2 shows the structured flowchart of computer data processor 60 as shown in Figure 1.As shown in Figure 2, the data that data acquisition unit gathers are stored in storer 61 by interface unit 68 and bus 64.Store configuration information and the program of computer data processor in ROM (read-only memory) (ROM) 62.Random access memory (RAM) 63 is for keeping in various data in processor 66 courses of work.In addition, in storer 61, also store for carrying out the computer program of data processing.Internal bus 64 connects above-mentioned storer 61, ROM (read-only memory) 62, random access memory 63, input media 65, processor 66, display device 67 and interface unit 68.

After operational order the user by input media 65 inputs such as keyboard and mouse, the instruction code instructs processor 66 of computer program is carried out predetermined data processing algorithm, after obtaining data processed result, it is presented on the display device 67 such as LCD display, or the direct formal output result with hard copy such as printing.

Fig. 3 shows the structured flowchart according to the controller of embodiment of the present invention.As shown in Figure 3, controller 50 comprises: control module 51, according to the instruction from computing machine 60, control radiographic source 10, load carrier 40 and detection and harvester 30; Trigger pip generation unit 52, for producing the trigger command of the action be used for triggering radiographic source 10, detection and harvester 30 and load carrier 40 under the control of control module; The first drive motor 55, it drives load carrier 40 to rise or descend at the trigger command produced under the control of control module 51 according to trigger pip generation unit 52; Elevation information acquiring unit 53, it is along with the motion of load carrier 40, to the elevation information of control module 51 feedback load carriers; The second drive motor 56, the trigger command that it produces under the control of control module 51 according to trigger pip generation unit 52 drives load carrier 40 rotations; Angle information acquiring unit 54, it obtains the anglec of rotation of load carrier 40 in load carrier 40 rotary courses, feeds back to control module 51.

According to the embodiment of the present invention, above-mentioned elevation information acquiring unit 53 and angle information acquiring unit 54 are all photoelectric code disks, and it possesses jamproof advantage.

According to embodiments of the invention, by measuring density and the atomic number of liquid in liquid article, and whether density and atomic number that judgement is measured drop in predefined hazardous location, and inspection method of the present invention can be used for detecting dangerous material.For density and atomic number, safe liquid (such as beverage, skin care item, cosmetics etc.) and dangerous liquid (such as flammable liquid, liquid explosive, strongly corrosion liquid etc.) have very big-difference.Such as, as the water of safe liquid, density is approximately 1 (characteristic density 1.11), atomic number is approximately 7.51.And, as the alcohol of dangerous liquid, its density is approximately 0.79 (characteristic density 0.89), atomic number is approximately 6.47.Utilize the method for pattern-recognition, can safe liquid and dangerous liquid be separated according to density and atomic number.

Fig. 4 A and 4B show the schematic diagram according to the method for inspection liquid article of the present invention.In the two-dimensional space that density and atomic number form, mark one or more zones, when the density of checking matter and atomic number drop in these zones, be judged to safe liquid, otherwise be judged to dangerous liquid.And definite method in safe liquid zone is, survey a large amount of safe liquid and dangerous liquid, get safe liquid and concentrate and the more sparse zone of dangerous liquid, as the safe liquid zone.As shown in Figure 4 A, by density and the atomic number of the various liquid of actual measurement, determine the zone that safe liquid falls in density and atomic number two-dimensional space, and the zone at dangerous liquid place.Then, as shown in Figure 4 B, the zone at safe liquid place is shunk in order to improve the sensitivity detected.Like this, after the method by above-mentioned has obtained the density and atomic number of liquid article, just can judge whether it is dangerous material in the position on two-dimensional space according to it.

Fig. 5 is the schematic diagram of the relation for DR imaging and CT imaging are described.According to the embodiment of the present invention, at first the liquid towards article carry out the DR imaging, so that then the liquid part in the judgement liquid article only carries out the CT imaging for certain position in the liquid part, in order to improve the speed checked.

Fig. 6 and Fig. 7 show respectively the example of DR imaging.As shown in Figure 6, after certain liquid article is carried out to the DR imaging, by the as described below position that pixel value analysis is judged to liquid in liquid article.As shown in Figure 6, only comprise a kind of liquid in this liquid article.But, as shown in Figure 7, due to the absorption coefficient difference of different liquids to liquid, when liquid article comprises two kinds or two or more liquid, and, while in liquid, layering occurring, carry out pixel analysis by the DR image to obtaining after the DR imaging and judge the interfacial position between liquid.Then, carry out the CT imaging for different liquid.

Fig. 8 shows the overview flow chart according to the liquid article examination method of first embodiment of the invention.As shown in Figure 8, for example, during being open to the custom, the liquid article that need to carry the passenger carries out safety inspection.At first at step S111, the operator is placed on tested liquid article on load carrier 40.

Next, at step S112, the operator presses start button and starts to carry out DR scanning, to generate the DR image, as shown in Figures 6 and 7.

As mentioned above, the purpose of carrying out DR scanning is: the one, obtain the fluoroscopy images of tested liquid article, and make the operator can see the inner structure of tested liquid clearly; The 2nd, software can, according to DR image automatic identification liquid position, guide next step CT imaging; The 3rd, the user can specify the position that need to carry out CT imaging and inspection at the DR image, guides next step CT imaging.Back will be described the detailed process of DR imaging in detail.

Should be noted that, DR scanning is not necessary.In order to accelerate inspection speed, can by DR, not scan to guide CT scan, but directly CT scan is carried out in predetermined some positions.Such as, through investigation, known 5 centimetres, the distance bottle end carry out CT scan the time, can be checked through the liquid position of most of liquid commodity, can use from the height of 5 centimetres at the bottom of bottle as predetermined scanning height.In addition, the operator can arrange suitable height by rule of thumb by range estimation checking matter size, and such as the scanning height that tank shape cola is set is 3cm, and at the bottom of arranging bottle, thicker scanning height vinous is 10cm.

After obtaining the DR image, at step S113A, the DR image is analyzed, automatically determine the scanning position of CT imaging, or, at step S113B, by the input media 65 of operator's operation such as mouse, specify the position that will carry out CT scan.Like this, because CT scan is carried out in representational position in liquid towards article only, thereby accelerated inspection speed, and can not reduce and check on the quality.

After the position of having determined CT scan, carry out the CT scan process at step S114, namely for above-mentioned definite scanning position liquid towards article, carry out CT scan, obtain the CT scan data, and calculate CT image reconstruction according to rebuilding.Each pixel of this CT image has represented density and the atomic number of appropriate section in the liquid article.

Then, at step S115, computing machine is analyzed the CT image by execution analyzer, obtains density and the atomic number of measurement.And then, at step S116, whether density and the determined point of atomic number of judgement actual measurement have dropped in the presumptive area in two coordinate spaces of density-atomic number.At step S117, if the determined point of density and atomic number has dropped in predetermined explosive area, show that this liquid article is suspicious or is likely dangerous material, sends warning to the operator, or prints check result.

Describe the detailed operating process of above-mentioned each step in detail below in conjunction with accompanying drawing 9～14.Fig. 9 shows the process flow diagram of DR imaging process, and Figure 10 shows in the DR imaging process and to survey and the arrangement mode of the DR view data that harvester 30 gathers.

As shown in Figure 9, in the DR imaging process, at step S210, from computing machine 60 to controller, 50 send order, to drive load carrier 40 along 20 vertical movements of object passage.Controller 50, in the process of load carrier vertical movement, is monitored the height of load carrier in real time by elevation information acquiring unit 53.

At step S211, controller 50 is given and is surveyed and a trigger pip of harvester 30 transmissions every certain height (such as 1 millimeter).Survey and after harvester 30 receives this trigger pip, the output signal of each detector is once gathered, acquisition high energy detection data and low energy detection data, and be saved in its built-in impact damper.

At step S212, judge whether load carrier 40 reaches specified altitude assignment, such as 500 millimeters.If do not reach yet, flow process forwards step S210 to, continues aforesaid operations.

If load carrier 40 arrives above-mentioned predetermined height, controller 50 is no longer given and is surveyed and harvester 30 transmission trigger pips.Computing machine 60 reads the high low energy detector signal collected from detection and harvester 30, is arranged as the form of data matrix, becomes the DR image.Each pixel of DR image, recorded ray and penetrated remaining intensity after object, comprises low energy ray intensity and high-energy ray intensity.

As mentioned above, the scanning position of follow-up CT imaging is all determined on the DR image.No matter be to use the mode of identification automatically, or the mode of artificial appointment, be all at first on the DR image, to obtain a line number, and then computing machine is converted to the load carrier height by this line number, and after instruction control unit 50 drives load carriers 40 to move to assigned address, then carry out the CT imaging.

From DR imaging flow process, every a line of DR image, corresponding to specific load carrier 40 height.While supposing that the DR imaging process starts, the load carrier height value is 0, and in imaging process, load carrier constantly descends, and every the h millimeter, triggers once and gathers, and the m in the DR image is capable so, and its corresponding load carrier height is-m*h.

Figure 11 shows the process flow diagram of the DR image being processed to determine the CT scan position.

In the DR image, at the bottom of tested liquid article generally is divided into bottle, several parts such as liquid part, bottleneck, bottle cap, liquid part (multilayer may be arranged) wherein can be extracted by image analysis technology, and determine each layer of CT scan position.

At step S310, the high low energy data of DR image are merged and level and smooth, obtain the monodrome DR image that noise is less.For example, the concrete grammar that high low energy merges can be directly to select a kind of as fusion results in high low energy data, can be also the weighted array of high low energy data.Level and smooth method can be to use Gaussian filter to carry out the filtering processing to image.

At step S311, extract the tested liquid article (prospect) in level and smooth rear DR image, remove air (background).Concrete grammar can be to set a threshold value, and by value, at this, the pixel below threshold value is classified as foreground pixel, and other pixels are classified as background pixel.The reason that adopts threshold value to remove background is: tested liquid article has blocked ray, so its corresponding DR pixel value lower (DR recording image be the residual intensity of ray).

At step S312, extract the horizontal edge pixel in level and smooth rear DR image.Concrete grammar can be: to each pixel of DR image, calculate the difference value of neighbor on itself and vertical direction; If this difference value arrives greatly certain more than threshold value, just think that this pixel belongs to the horizontal edge pixel.

At step S313, extract level and smooth after horizontal edge in the DR image capable, horizontal edge is capable of the interface between multilayer liquid at the bottom of bottle and in the interface of the interface of the interface of liquid, liquid and air, bottle cap and air or container.Concrete grammar can be: to every a line of along continuous straight runs in the DR image, add up the ratio of its horizontal edge number of picture elements and foreground pixel number, if ratio arrives greatly certain threshold value above (such as 50%), this line is classified as to horizontal edge capable.

At step S314, the DR image is carried out to vertical partitioning, and get rid of non-liquid regions.Each horizontal edge in the DR image is about to the DR image and has been divided into a plurality of zones, comprises successively from the bottom up: air (if any), bottle cap etc. in the bottle end, liquid (according to the difference of density, multilayer may be arranged), bottle.By formulating filter criteria, can get rid of the on-liquid zone, concrete criterion as:

A) in vertical direction, line number is less than the zone of a certain threshold value, gets rid of.The zone that line number is less, the very little zone of thickness namely, narrow and small space (such as the air of pop can inner top) at the bottom of being likely bottle, between bottle cap or liquid in container and container top.Determining of concrete threshold value, can determine by air layer thickness in the bottle end, bottle cap and the container of investigating various liquid package containers.

B) in the horizontal direction, the average foreground pixel number of each row is less than the zone of certain threshold value, gets rid of.These zones are often corresponding to elongated bottleneck.Determining of concrete threshold value, the width that can obtain various liquid package container bottlenecks by realization is determined.

At step S315, determine the CT scan position of liquid regions (may have a plurality of), complete the Hierarchical Location of liquid.After getting rid of the on-liquid zone, remaining zone (may have a plurality of) is classified as liquid regions.Get the central row of these zones on short transverse, as the CT scan position.

Described above is the process of automatically determining the CT scan position.But, in the situation that manual invisible scanning position, the operator will carry out the row of CT scan by input media 65 direct appointment on the DR image shown, as the CT scan position.

Figure 12 shows the CT imaging process, and Figure 13 shows the arrangement mode of CT data for projection in the CT imaging process.

As shown in figure 12, after the position of having determined CT scan, carry out the CT imaging process, namely in performed CT scan position, carry out the CT imaging, generate density and atomic number image about a tomography of checking matter, to carry out the measurement of fluid density and atomic number.As mentioned above, owing to only CT scan being carried out in typical position, so can greatly save the time of being open to the custom.

At step S410, computing machine 60 sends order to controller 50, drives load carrier 40 rotation predetermined angulars, for example 1 degree.In the process that controller 50 rotatablely moves at load carrier, by angle information acquiring unit 54, monitor in real time the load carrier angle.

At step S411, when turning over 1 degree, controller 50 is given and is surveyed and a trigger pip of harvester 40 transmissions.Survey and after harvester 40 receives trigger pip, the output signal of each detector is once gathered, and be saved in its built-in impact damper.

Then, at step S412, whether judgement accumulative total rotational angle reaches one week.If do not reach one week, flow process forwards step S410 to, continues above-mentioned operating process.

If, after the accumulative total rotational angle reaches specified angle (such as 360 degree), at step S413, rotatablely move and stop, controller 50 is no longer given and is surveyed and harvester 30 transmission trigger pips.Computing machine 60 reads the high low energy detector signal collected from detection and harvester 30, is arranged as the form of data matrix, becomes the CT data for projection, as shown in figure 13.Each pixel of CT data for projection, recorded ray and penetrated remaining intensity after object, comprises low energy ray intensity and high-energy ray intensity.

At step S414, computing machine 60 utilizes the dual intensity reconstruction algorithm, according to high low energy CT data for projection, rebuilds and obtains density and the atomic number image on tomography, i.e. CT image.Each pixel in the CT image, recorded density and the atomic number of tested object at this pixel correspondence position.

The following describes the process of rebuilding faultage image from high low energy CT data for projection.

● the CT mathematical principle

Two dimensional Distribution u (x, y) is asked to line integral along certain direction θ, just obtain the function p of one dimension _θ(t), this function is called the projection of u (x, y) in the θ angle.If can access the projection p of all directions _θ(t), can convert accurate Calculation according to Radon so and obtain Two dimensional Distribution u (x, y).The process that obtains Two dimensional Distribution from projection is called reconstruction.

In practical application, X-ray machine and detector are around object rotation one circle, and the attenuation coefficient that just measures certain section of object is distributed in the projection of all directions, thereby can rebuild the attenuation coefficient Two dimensional Distribution that obtains the object section according to the CT principle.

● the sill decomposition model

In small-sized X-ray safety inspection system, in related energy range (<200keV), the material line attenuation coefficient can carry out approximate representation with following analytical expression (1).

μ(E)＝a ₁f _p(E)+a ₂f _KN(E) (1)

$a_1=\frac{\mathrm{\&rho;Z}}{M}{Z}^n---\left(2\right)$

$a_2=\frac{\mathrm{\&rho;Z}}{M}---\left(3\right)$

In formula (1), f _p(E) mean the variation relation of photoelectric effect cross section along with energy, f _KN(E) mean the variation of Compton scattering cross section along with energy, f _pAnd f (E) _KN(E) known analytical expression is all arranged.Constant a ₁And a ₂Relevant with atomic number, mass number and the density of material, its expression formula is as shown in (2) and (3) formula, and wherein Z means atomic number, and M means mass number, and ρ means density (g/cm ³), n is constant.

Because the line attenuation coefficient of every kind of material can by two coefficient a1 in formula (1) and a2 is unique be determined, therefore can choose two kinds of sills, such as carbon and aluminium, mean other all materials with the linear combination of the line attenuation coefficient of sill, shown in (4):

μ(E)＝b ₁μ ₁(E)+b ₂μ ₂(E) (4)

Wherein, the line attenuation coefficient that μ (E) is any one material, μ ₁And μ (E) ₂(E) be the line attenuation coefficient of selected two kinds of sills, b ₁And b ₂Be called the sill coefficient.

According to formula (5), 2 times of the definition atomic number is characteristic density with the ratio of mass number and the product of density.

${\mathrm{\&rho;}}^{*}=\mathrm{\&rho;}\frac{2Z}{M}---\left(5\right)$

Atomic number and the characteristic density of supposing two kinds of sills are respectively

With

Can derive the expression formula of the atomic number of any one material and characteristic density according to top formula (1)～(4) so as follows:

${\mathrm{\&rho;}}^{*}=b_1{\mathrm{\&rho;}}_1^{*}+b_2{\mathrm{\&rho;}}_2^{*}---\left(6\right)$

$Z={\left(\frac{b_1{\mathrm{\&rho;}}_1^{*}{Z}_1^n+b_2{\mathrm{\&rho;}}_2^{*}{Z}_2^n}{b_1{\mathrm{\&rho;}}_1^{*}+b_2{\mathrm{\&rho;}}_2^{*}}\right)}^{1/n}---\left(7\right)$

● the sill projection model

The power spectrum that X-ray tube produces is generally continuous spectrum, and detector neither constant to the energy response function of X ray.Suppose power spectrum N (E) and energy response function P _d(E) product is S (E), and by S (E) normalization,

${\&Integral;}_0^{E_m}S\left(E\right)\mathrm{dE}=1---\left(8\right)$

The expression formula of the projection value on projection line is following integration type so:

$p=-\ln \frac{I}{I_0}=-\ln {\&Integral;}_0^{E_m}S\left(E\right)\exp (-\underset{l}{\&Integral;}\mathrm{\&mu;}(E,x,y)\mathrm{dl})\mathrm{dE}---\left(9\right)$

In formula (9), I ₀Mean that respectively ray is by before object decay and the detector readings value after decay, E with I _mMean the ceiling capacity of ray, l means the path that ray passes.

Formula (9) is the relation of measurement projection value p and the Two dimensional Distribution μ (x, y) of real system.Can find out, due to the X ray pleochroism, formula (9) does not mean the line integral of μ (x, y) along certain straight line, thereby does not meet the requirement of CT mathematical principle.Conventional reconstruction algorithm is ignored this inconsistency, and the artifact that μ (x, the y) image that reconstruction obtains contains cup-shaped, be called the sclerosis artifact.

Existing dual intensity CT method first adopts conventional reconstruction algorithm to obtain two groups of μ (x, y), then calculates the information such as atomic number and density.But can not eliminate so the pleochromatic impact of ray.The thinking that the present invention adopts sill to decompose has solved this problem.

The sill decomposition model is updated in formula (9), can obtains the projection value expression formula based on the sill coefficient:

$p=-\ln {\&Integral;}_0^{E_m}S\left(E\right)\exp (-{\&Integral;}_l[{\mathrm{\&mu;}}_1\left(E\right)b_1(x,y)+{\mathrm{\&mu;}}_2\left(E\right)b_2(x,y)\left]\mathrm{dl}\right)\mathrm{dE}---\left(10\right)$

Following formula for 1 the integration along path in above formula is expressed:

∫ _lb ₁(x，y)dl＝B ₁ (11)

∫ _lb ₂(x，y)dl＝B ₂ (12)

According to above-mentioned (11), (12) two formula definition, claim B ₁And B ₂For sill coefficient b ₁(x, y) and b ₂The projection of (x, y).Supposed to get the complete sill coefficient projection under each angle, so just can rebuild and obtain sill coefficient b according to the CT reconstruction theory ₁And b ₂Distribution, thereby calculate the atomic number of object and characteristic density distributes according to the sill decomposition model, and the line attenuation coefficient value under energy arbitrarily.

● solving of sill coefficient projection

Dual intensity CT is recording projection data under two energy, just obtains following dual intensity data for projection:

$p_1(B_1,B_2)=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-B_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(13\right)$

$p_2(B_1,B_2)=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-B_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(14\right)$

Measuring (p ₁, p ₂) after, can solve and obtain (B according to equation (13) and (14) ₁, B ₂).But because above-mentioned two equations are the logarithmic integral equation, can't Analytical Solution.The common calculated amount of Iterative solution method for nonlinear equation is very large, and is not easy to obtain stable solution.

Notice, when ray is d through thickness ₁And d ₂Sill 1 and 2 after, the dual intensity projection measured is as following expression formula:

$p_1=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-d_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(15\right)$

$p_2=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-d_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(16\right)$

Contrast (13), (14) and (15), (16) can be found out, suppose that the data for projection measured is to (p ₁, p ₂) identical, the sill data for projection is to (B so ₁, B ₂) combine (d with the thickness of sill ₁, d ₂) be identical.

Measure the dual intensity projection under the different-thickness combination, just can obtain the dual intensity data for projection to (p ₁, p ₂) with sill coefficient data for projection to (B ₁, B ₂) corresponding relation, form look-up table.According to (p ₁, p ₂) calculating (B ₁, B ₂) just can be according to look-up table, utilize linear interpolation to realize, replace complicated solution procedure.

Figure 14 shows the process of measuring the liquid attribute.

As shown in figure 14, at step S510, density image and atomic number image are merged with level and smooth, obtain the monodrome CT image that noise is less.The concrete grammar merged can be directly to select a kind of as fusion results in density image and atomic number image, can be also both weighted array.Level and smooth method can be to use Gaussian filter to carry out the filtering processing to image.

At step S511, extract the checking matter (prospect comprises liquid and packing thereof) in level and smooth rear CT image, remove air (background).Concrete grammar can be to set a threshold value, and by value, at this, the pixel more than threshold value is classified as foreground pixel, and other pixels are classified as background pixel.This is that the density of tested liquid article and atomic number are relatively large because density and the atomic number of air are almost 0.

At step S512, extracting liq pixel in foreground pixel.Concrete grammar can be: one of model and CT scheme corresponding bianry image, and the value of foreground pixel is 1, and the value of background pixel is 0; Then this bianry image is carried out to repeatedly erosion operation, corrode a pixel at every turn, the pixel that last value is 1 is the liquid pixel.This is always in the inside of packing material, by repeatedly corroding and can remove step by step packing material because of liquid.The number of times of corrosion can be set by realizing the thickness of determining packing material.

At step S513, average density and the average atomic number of all liq pixel in statistics CT figure, as the Output rusults of this measurement.

In addition, if determine that in the DR image analysis process liquid state is layering, carries out step as above for every layer of liquid, and then judges whether each layer of liquid is suspicious.Finally, report final check result to the operator.

[the second embodiment]

What the first top embodiment was described is the situation that at every turn detects the single-piece liquid article, describes the operating process that simultaneously detects many liquid articles in detail below in conjunction with Figure 15～18.The difference of the second embodiment and the first embodiment is, because there are many liquid articles, need to be after the CT imaging completes, the position of the imaging results shown on display is corresponding with the position of object on load carrier, thereby convenient operation person understands fully that part liquid article is dangerous material.Figure 15 A and Figure 15 B show the schematic diagram of the CT image of rebuilding in the situation according to many liquid articles of detection of second embodiment of the invention.

For example, the operator observes the checking matter on load carrier in the mode of overlooking, and this just requires to check that the position of finishing each object on rear each layer of CT image must be consistent with the load carrier vertical view.

Figure 16 A-16K shows after the CT imaging completes, and how CT reconstructed image and/or load carrier is rotated to its process consistent with the relative position of object before CT scan that make.

Figure 16 A shows when CT imaging for the first time starts, and the vertical view of load carrier 40, wherein by the angle of arrow indication load carrier.Figure 16 B shows the CT image before CT image rotation for the first time, and the vertical view of its load carrier when imaging starts for the first time is consistent, the rotating range of dotted line sign load carrier wherein.Figure 16 C shows the image after ground floor CT image rotation, because the anglec of rotation is zero, therefore in fact without this layer of CT image is rotated.

Figure 16 D shows when the n time CT imaging starts, the vertical view of load carrier.From Figure 16 D, can find out, when the n time CT imaging starts, load carrier is than the situation before CT imaging for the first time, with an angle.Figure 16 E shows the image before the n time CT image rotation, and when it starts with the n time imaging, the vertical view of load carrier is consistent.Figure 16 F shows the image in Figure 16 D is rotated, and makes the schematic diagram of itself and ground floor CT image alignment.

Figure 16 G shows when the CT imaging starts the last time, and the vertical view of load carrier can be found out when load carrier now starts than CT imaging for the first time with an angle.Figure 16 H shows the image before the N time CT image rotation, and when it starts with the N time imaging, the vertical view of load carrier is consistent.Figure 16 I shows the image in Figure 16 H is rotated, and makes the schematic diagram of itself and ground floor CT image alignment.

After Figure 16 J shows last CT imaging end, the vertical view of load carrier, the situation before wherein starting than CT imaging for the first time, have an anglec of rotation.Figure 16 K shows after imaging finishes load carrier is rotated and makes it consistent with the image that CT imaging for the first time obtains.

After all CT imaging processes finish, each layer of CT image and load carrier are carried out to angular setting one time.At first, load carrier angle while starting according to each CT imaging (this angle can obtain by angle information acquiring unit 54), each layer of CT image is rotated to processing, the position of same object in each layer of CT image is consistent, such as snapping to ground floor CT.Then, adjust the angle of load carrier, the vertical view of load carrier and CT image are consistent.

For example, suppose to have carried out altogether N CT imaging, when the n time CT imaging starts, the load carrier angle is α _n, during end, the load carrier angle is β _n, on vertical view, load carrier is counterclockwise to rotate.For the position of the position of object in n layer CT image on all with the 1st layer is consistent, only need be by n layer CT image by anglec of rotation α counterclockwise _n-α ₁Get final product.After image rotating, in order to make object, at load carrier vertical view and CT figure, be consistent, only need be by load carrier by counter clockwise direction anglec of rotation 360-(β _N-α ₁) get final product.

Figure 17 shows in the situation that many process flow diagrams that tested object is checked.As shown in figure 17, at step S711, the operator powers on to system, and login inspection interface, enters ready state after System self-test.Then, the operator is by many checking matters, and for example object A and object B are placed directly on load carrier 40 and press the inspection knob.Here, suppose that object A is placed on the position, the upper right corner of load carrier, and object B is placed on the position, the lower left corner of load carrier.

Next, at step S712, the operator presses start button and starts to carry out DR scanning according to the mode with identical as mentioned above, to generate the DR image.

After obtaining the DR image, at step S713A, the DR image is analyzed, automatically determine the scanning position of CT imaging, or, at step S713B, by the input media 65 of operator's operation such as mouse, specify the position that will carry out CT scan.Like this, because CT scan is carried out in representational position in liquid towards article only, thereby accelerated inspection speed, and can not reduce and check on the quality.

After the position of having determined CT scan, carry out the CT scan process at step S714, namely for above-mentioned definite position liquid towards article, carry out CT scan, obtain the CT scan data, and according to the reconstruction algorithm CT image reconstruction.Each pixel of this CT image has represented density and the atomic number of appropriate section in the liquid article.When liquid exists in the situation of multilayer, for each layer, carry out CT scan.

At step S715 and S716, after last CT imaging finishes, method is adjusted load carrier angle and each layer of CT image angle as described above, the position of each object in each layer of CT image is consistent (such as alignment ground floor CT image), with object, the physical location on load carrier is consistent (such as consistent with vertical view) simultaneously, so that distinguish object B and object A.

At step S717, every layer of CT image carried out to image dividing processing (such as using watershed algorithm), obtain the wherein liquid regions of every checking matter, the density of each pixel and atomic number average in step S718 adds up each liquid regions, in step S719 judgement in the density measured for each liquid regions and the true point of the atomic number presumptive area in whether having dropped on density-atom coefficient coordinate space, whether this layer of liquid differentiating this part checking matter at step S720 accordingly is dangerous material.

At step S721, gather each layer of inspection conclusion and be prompted to the operator.A kind of method of summary is: when only in all CT images, all liq zone all is judged to the danger product, the conclusion of this inspection is " safety "; Otherwise the conclusion of this inspection is " suspicious ".In addition, every layer of CT image carried out the colorize processing and be shown to the user, the checking matter that is judged to suspicious object in CT figure is used a kind of color (such as redness), is judged to the another kind of color (such as green) of use of safe liquid.

Described above is the situation that simultaneously checks two liquid articles, in the time will checking more liquid articles simultaneously, see the position of understanding each liquid article for the ease of operating personnel, as shown in figure 18, mark off a plurality of zones on surface to load carrier carrying liquid article, for example the A district in Figure 18, B district, C district and D district, operating personnel can be placed on each part liquid article in corresponding zone like this, and input fluid identification information separately for regional.

[the 3rd embodiment]

In order further to improve detection efficiency and to prevent that elongated tested liquid article directly is placed on load carrier while causing detecting, easily produce unstable and impact detects the problem of effect, the 3rd embodiment proposes many objects are placed in the lattice bucket.

Therefore, the difference of the 3rd embodiment and the second embodiment is, in the process that checks many objects, has used the lattice bucket.Describe the specific operation process according to the checkout equipment of present embodiment in detail below in conjunction with accompanying drawing 19～24.

Figure 19 shows the side view according to the lattice bucket of present embodiment, and Figure 20 shows the vertical view of lattice bucket, and Figure 21 shows the backplan of lattice bucket.

As shown in figure 19, lattice bucket 70 comprises bottom and the sidewall be coupled with bottom.Be provided with the projection of a plurality of tapers or other shapes on the lower surface of bottom.These three tapered protrusion can be inserted in pilot hole corresponding on load carrier 40, thereby in the load carrier rotary course, lattice bucket 70 rotates together with load carrier 40, prevents from producing relative motion between the two.

In addition, as shown in figure 19, at the top of sidewall, within one week, be provided with flange, handled easily person grasps and carrying.Sidewall is columned or taper, and can be by having the elastic side material, and for example tygon (PE) or aluminium are made.

Figure 20 is the vertical view of three kinds of lattice buckets.As shown in the figure, be provided with one or more lattice parts in the space formed by bottom and sidewall, this space is divided into to a plurality of spaces as required, be respectively used to place liquid article.Like this, in the time will detecting many liquid articles, these many liquid articles are placed on respectively in the space of being divided by the lattice parts simultaneously, these liquid articles are detected simultaneously.In this case, can on the outside surface of sidewall, mark be set, be convenient to when detecting detecting the location of article in bucket.For example, have one bottle when suspicious in four article being detected, can be according to these part article the relative position with respect to the mark arranged on sidewall, to user report, be which part article is suspicious.

For example, as shown in the left hand view of Figure 20, be provided with the mark of the circle that cross section is preliminary dimension at the upside of lattice parts, or other little of the Length Ratio of certain lattice parts, thus as location liquid article mark used.

Figure 21 is the backplan of lattice bucket.Be evenly distributed with three projections on the lower surface of bottom.It can be also inhomogeneous that but these three projections distribute.

Figure 22 shows the process that how automatically to detect lattice bucket and mark in checking process.As mentioned above, the lattice cylinder has specific structure, and in can processing with image, the method for stencil matching commonly used detects.The first bucket of take with the cross lattice is example, step S810 can model one width with the template image of cross, and the center of this template is placed in to CT picture centre to be identified, obtain matching value.

Then at step S811, judge whether this matching value is greater than predetermined threshold value, if result negate, after the rotary template image, until the matching degree maximum of template image and CT image.If matching degree is greater than certain predefined threshold value, thinks in CT figure and have the lattice cylinder, otherwise think in CT figure and do not have the lattice cylinder.

If there is the lattice cylinder in CT figure, can further according to specifically labelled characteristics, carry out the detection and location mark at step S812.The first cylinder of still take with the cross lattice is example, and its telltale mark is positioned at the top of a frame bar, makes this frame bar short than other three frame bars.After using template matching method to confirm in CT figure to have the lattice cylinder, cross curve when matching degree is maximum in template image just in time overlaps with frame bar; By the length of four frame bars relatively, extract wherein the longest one, can obtain telltale mark.

After the multi-Slice CT imaging, at first every one deck CT image is carried out to the detection of lattice cylinder and telltale mark detection.If the lattice cylinder all do not detected in each layer of CT image, think that the operator does not use the lattice cylinder; If at least in one deck CT image, the lattice cylinder detected, think that the operator has used the lattice cylinder; If differ in the telltale mark position that each layer detects, the signal intensity maximum final telltale mark of conduct wherein.Describing a method of telltale mark signal intensity in certain one deck CT is: deduct mean value by the maximal value of four cut-off rule length of this layer, its difference is larger, and the telltale mark signal is stronger.

Figure 23 A-23D shows the schematic diagram of rotary barrel in testing process.The telltale mark that only lattice need be detected to cylinder is adjusted to precalculated position, each lattice can be adjusted to assigned address.The first cross lattice cylinder of take is example, and the CT picture centre of take is set up polar coordinate system as coordinate origin, and the position of each lattice is determined by specifically labelled angle coordinate is unique.Supposing the system final definite corresponding polar angle of telltale mark in various CT images is γ, and the predefined adjustment aim of system is θ, so only each layer of CT image and load carrier anglec of rotation θ-γ can need be completed to adjustment, be illustrated in fig. 24 shown below.

As shown in Figure 23 A and 23B, by an angle of lattice bucket rotation, to reach the position required in advance.Equally, every layer of resulting image of CT imaging is rotated, makes its angle with postrotational lattice bucket consistent.

Figure 24 shows the process flow diagram according to the checking process of present embodiment.Due to identical to step S721 with the step S711 of above-mentioned the 3rd embodiment from step S911 to step S921, step S922 is only described to step S926. here

At step S922, analyze the CT image, whether with lattice, detect cylinder in step S923 judgement.If do not detect cylinder, this checks and finishes.

Detect bucket if used, at the telltale mark of step S924 recognition detection cylinder, determine the position of each lattice.Then at step S925, load carrier angle and each layer of CT image angle are adjusted for the second time, will on load carrier, be detected the position of each lattice in cylinder, and the position of each lattice on each layer of CT image of liquid, all adjust on preposition.

At step S926, system is listed in every layer of CT image the check result that drops on each liquid regions in each lattice part, is aggregated into the inspection conclusion of each lattice and is prompted to the user.According to a kind of method of summary of present embodiment, be: for certain lattice, only in all CT images, drop in this lattice when all liq zone all is judged to safe liquid, the inspection conclusion of these lattice is " safety "; Otherwise the inspection conclusion of these lattice is " suspicious ".

[modification 1]

Although above with first carry out the DR imaging then carry out CT be imaged as the example embodiments of the invention are illustrated, also can directly carry out the spiral CT imaging, come the liquid towards article to be checked.

The liquid towards article carry out spiral CT and check that resulting is one group of spiral CT image, by relatively and analyze the pixel in this group CT image, just can determine the position of liquid in liquid article, and whether layering of liquid, then utilize with as described above similarly method obtain the physical property values of the liquid of each layer of position, for example density and atomic number.For example, when the liquid article to as shown in figure 25 carries out the spiral CT imaging, if take 2cm as screw pitch is scanned, will obtain one group of CT image as shown in Figure 26 A-26M.Like this, by analyzing the pixel in each spiral CT image, the position that just can learn liquid in liquid article.The spiral CT imaging here can adopt coarse pitch CT imaging or conventional pitch CT imaging.

Equally, as those of ordinary skill in the art institute clearly, above-mentioned variant embodiment also can be applied to many bottles of detections as the second embodiment and the 3rd embodiment.

In addition, take density and atomic number to be illustrated as example although top, the present invention can only carry out with one of density or atomic number equally, or carries out the identification of dangerous material by other more physical attributes.In the former case, in checking process, judge by judging whether a kind of physical property values drops in predetermined scope whether liquid is dangerous material, under latter event, in checking process, by judging whether to be dropped in the presumptive area in the hyperspace limited by these attributes to draw by the determined point of multiple physical property values, judge whether liquid is dangerous material.

[modification 2]

Although above first to carry out the DR imaging, then carry out dual intensity CT imaging and obtain density and the atomic number of liquid, but the DR imaging here is not necessary, because can specify in advance preposition to carry out dual intensity CT imaging for different liquid articles, obtain density and the atomic number of liquid.

Top description is only for realizing embodiments of the present invention; it should be appreciated by those skilled in the art; the any modification or partial replacement do not departed from the scope of the present invention; all should belong to the scope that claim of the present invention limits; therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.

Claims (10)

1. the equipment checked with dual intensity spiral CT liquid towards article comprises:

Radiographic source, for sending high energy and low energy X ray;

Survey and harvester, for surveying and gather high energy and the low energy X ray that penetrates at least one tested liquid article;

Load carrier, carrying tested liquid article rotates around axle, and can lifting, make tested liquid article enter surveyed area, thereby the high energy sent by radiographic source and low energy ray can see through tested liquid article, described load carrier possesses a plurality of pilot holes, and the respective bump that has allowed to place the lattice bucket lower surface of a plurality of liquid articles is inserted into wherein;

Controller, control described radiographic source and detection and harvester tested liquid article carried out to the dual intensity Spiral CT scan, forms one group of spiral CT image of each at least one physical property values that all means tested liquid article;

Computing machine, analyze this group spiral CT image to determine the spiral CT image section of liquid, and the physical property values comprised in the spiral CT image section based on liquid judges in Zhong De position, the space of respective dimensions whether described tested liquid article is dangerous material.

2. equipment as claimed in claim 1, wherein said physical property values at least comprises density and the atomic number of tested liquid article.

3. equipment as claimed in claim 1, wherein said dual intensity Spiral CT scan is the screw with long screw pitch CT scan.

4. equipment as claimed in claim 1, wherein said computing machine judges whether described physical property values drops in the preset range limited by the reference physical property values, and the described liquid article that judges of the situation in described physical property values drops on described preset range is dangerous material.

5. equipment as claimed in claim 1, wherein said controller comprises:

Control module, control radiographic source, load carrier and detection and harvester according to the instruction from computing machine;

The trigger pip generation unit produces the trigger command of the action be used for triggering radiographic source, detection and harvester and load carrier under the control of control module;

The first drive motor, the trigger command produced under the control at control module according to the trigger pip generation unit drives load carrier to rise or descends;

The elevation information acquiring unit, along with the motion of load carrier, to the elevation information of control module feedback load carrier;

The second drive motor, the trigger command produced under the control at control module according to the trigger pip generation unit drives the load carrier rotation;

The angle information acquiring unit obtains the anglec of rotation of load carrier in the load carrier rotary course, feeds back to control module.

6. equipment as claimed in claim 5, wherein said elevation information acquiring unit and angle information acquiring unit are all photoelectric code disks.

7. the method checked with dual intensity spiral CT liquid towards article comprises:

Send high energy and low energy X ray from radiographic source;

Survey and gather the high energy and the low energy X ray that penetrate at least one tested liquid article;

Carrying tested liquid article with a load carrier rotates around axle, and can lifting, make tested liquid article enter surveyed area, thereby the high energy sent by radiographic source and low energy ray can see through tested liquid article, described load carrier possesses a plurality of pilot holes, and the respective bump that has allowed to place the lattice bucket lower surface of a plurality of liquid articles is inserted into wherein;

Tested liquid article is carried out to the dual intensity Spiral CT scan, form one group of spiral CT image of each at least one physical property values that all means tested liquid article;

Analyze this group spiral CT image to determine the spiral CT image section of liquid; And

Reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is dangerous material.

8. method as claimed in claim 7, wherein said physical property values at least comprises density and the atomic number of tested liquid article.

9. method as claimed in claim 7, wherein said dual intensity Spiral CT scan is the screw with long screw pitch CT scan.

10. method as claimed in claim 7, wherein the reference physical property values based on described physical property values and this liquid article judges that whether described tested liquid article is that the step of dangerous material comprises:

Judge whether described physical property values drops on by the described preset range limited with reference to physical property values; And

Situation in described physical property values the drops on described preset range described liquid article that judges is dangerous material.

Images