CN102095663B - Method and equipment for inspecting liquid substances - Google Patents

Abstract

The invention discloses a method and equipment for simultaneously inspecting a plurality of liquid substances by using dual-energy computed tomography (CT). The method comprises the following steps of: performing dual-energy CT scanning on inspected liquid substances at a plurality of positions to acquire dual-energy CT protection data; rotating CT images of the inspected liquid substances after performing the dual-energy CT scanning at each position so as to align the images formed by multiple times of scanning operation; performing CT reconstruction according to the projection data to acquire the CT images for representing physical attribute values of the inspected liquid substances; extracting the physical attribute values of the inspected liquid substances according to the CT images; and judging whether the inspected liquid substances are suspicious based on the physical attribute values and reference physical attribute values of the liquid substances. By the method, the liquid substances can be inspected rapidly.

Description

Liquid article examination method and equipment

The application submitted to the dividing an application of No. 200710180653.2 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 carry out by the liquid towards article 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. occured, the safety inspection work of aviation field more and more came 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 effective mode and means and carry out the fast and safely inspection of liquid article in luggage and articles.

Current, have the method for following four classes can be used 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 that sample is analyzed, and can not satisfy the on-the-spot demand that checks fast.

2) the electromagnetic method metering system of taking 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) phenomenon of " neutron activation " can appear in the use of neutron inspection method, and namely 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 can obtain the structural information of object, but can't judge whether keep drugs in liquid; This is because after keeping drugs in liquid, just composition changes, and obvious variation can't occur general structure.

In sum, check fast for liquid article, 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 to comprise the image of structural information, can not be for judging whether liquid article keeps drugs abundant foundation is provided.

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, a kind of method that a plurality of liquid articles is checked simultaneously with dual intensity CT has been proposed, comprise step: in a plurality of positions, tested liquid article is carried out the dual intensity CT scan, obtain dual intensity CT data for projection, after wherein carrying out the dual intensity CT scan for each position, rotate the CT image of tested liquid article, make the formed image alignment of Multiple-Scan; Carry out CT according to described data for projection and rebuild, obtain representing 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 the reference physical property values of described physical property values and this liquid article whether described tested liquid article is suspicious.

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 the CT scan 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 determine the CT scan position according to transmission image.

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

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

According to embodiments of the invention, the step that obtains 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 obtains 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, carry out CT according to described data for projection and rebuild, obtain representing that the step of CT image of the physical property values of tested liquid article 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, obtain representing the CT image of the corresponding two kinds of sill coefficients of tested liquid article; And the CT image of the corresponding two kinds of sill coefficients of liquid article tested according to described expression, generate the CT image of the tested liquid article physical property values of described expression.

According to embodiments of the invention, the step of extracting the physical property values of tested liquid article according to described CT image 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 based on the ginseng physical property values of described physical property values and this liquid article whether described tested liquid article is that suspicious step comprises: calculate the density of described tested liquid article and the difference between atomic number and reference density and atomic number; In the situation that greater than predetermined threshold value, thinking, described difference hidden drugs in described tested liquid article.

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

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

According to embodiments of the invention, described tested 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: with 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: with the CT image color of each tested liquid article.

In another aspect of this invention, proposed a kind of with dual intensity CT to the equipment that a plurality of liquid articles check simultaneously, comprising: radiographic source is used for sending ray; Survey and harvester, be used for surveying and gathering the ray signal that penetrates at least one tested liquid article; Controller, control described radiographic source and detection and harvester and in a plurality of positions, tested liquid article is carried out the dual intensity CT scan, obtain data for projection, after wherein carrying out the dual intensity CT scan for each position, rotate the CT image of tested liquid article, make the formed image alignment of Multiple-Scan; Rebuild the device of the CT image of the physical property values that represents tested liquid article from data for projection; And judge based on the reference physical property values of described physical property values and this liquid article whether described tested liquid article is suspicious device.

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 the delegation at least in transmission image; Described dual intensity CT scan is based on specified going and carries out.

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

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 the delegation at least in described appointment transmission image comprises: the operator utilizes input media to select the device of delegation at least from transmission image.

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

According to embodiments of the invention, the device of CT image of rebuilding the physical property values of the tested liquid article of expression from data for projection 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 device of 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 based on the reference physical property values of described physical property values and this liquid article whether described tested liquid article is that suspicious device comprises: calculate the density of described tested liquid article and the device of the difference between atomic number and described reference density and atomic number; In the situation that greater than predetermined threshold value, thinking, described difference hidden drugs in described tested liquid article.

According to embodiments of the invention, after described equipment also was included in and carries out the dual intensity CT scan for every row, the CT image of the tested liquid article of rotation made 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, the judged result of the tested liquid article of demonstration.

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: with 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, is divided into the discernible a plurality of zones of operating personnel on the surface of the described tested liquid article of described bearing structure carrying.

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 bucket of described load carrier carrying, a plurality of pilot holes are arranged, make the projection of described bottom of the barrel can be inserted in pilot hole corresponding on load carrier.

In still another aspect of the invention, proposed a kind of equipment that checks with dual intensity CT liquid towards article, having comprised: radiographic source is used for sending ray; Survey and harvester, be used for surveying and gathering the ray signal that penetrates at least one tested object; Controller is controlled described radiographic source and detection and harvester tested liquid article is carried out Spiral CT scan, forms one group of spiral CT image of each at least a physical property values that all represents tested liquid article; Analyze this group spiral CT image with the device of the spiral CT image section of definite liquid; And judge based on the reference physical property values of described physical property values and this liquid article whether described tested liquid article is suspicious device.

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

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, by the density of measuring is compared with atomic number with reference density with atomic number, can judge whether tested liquid article (such as wine etc.) keeps drugs (such as cocaine etc.).

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, the operator can add new tested class of liquids voluntarily according to concrete needs.

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

Description of drawings

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 shows the identification information of the various liquid articles of storage in database and the structure that attribute information adopts;

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

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 DR image is processed to determine the process flow diagram of 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 shows the process that database is expanded;

Figure 16 A and Figure 16 B show the schematic diagram of the CT image of rebuilding in situation according to many liquid articles of detection of second embodiment of the invention;

Figure 17 A shows after the CT imaging is completed to 17K, how CT reconstructed image and/or load carrier is rotated its process consistent with the relative position of object before CT scan that make;

Figure 18 shows in the situation that many process flow diagrams that tested object checks;

Figure 19 shows the vertical view according to the load carrier of second embodiment of the invention;

Figure 20 shows the side view according to the lattice bucket of present embodiment;

Figure 21 shows the vertical view of lattice bucket;

Figure 22 shows the backplan of lattice bucket;

Figure 23 shows the process that how automatically to detect lattice bucket and mark in checking process;

Figure 24 A shows the schematic diagram of rotary barrel in testing process to 24D;

Figure 25 shows the process flow diagram according to the checking process of the 3rd embodiment;

Figure 26 A is the change curve of explanation liquid density after having hidden drugs;

Figure 26 B is the change curve of explanation liquid atomic number after having hidden drugs;

Figure 26 C is the change curve of explanation liquid characteristic density after having hidden drugs;

Figure 27 describes the process flow diagram of the inspection method of the 4th invention embodiment in detail;

Figure 28 is the schematic diagram that explanation liquid towards article carry out Spiral CT scan;

Figure 29 A is that explanation liquid towards article carry out the resulting image of Spiral CT scan to 29M.

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 used for representing 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, the checkout facility according to present embodiment comprises: send the radiographic source 10 that checks with dual-energy x-ray, such as X-ray machine; Load carrier 40, the tested liquid article of its carrying rotates around axle Z, and can lifting, makes tested liquid article enter surveyed area, thereby can see through tested liquid article by the ray that radiographic source 10 sends; Survey and harvester 30, it is detector and the data acquisition unit with integral module structure, be used for surveying the dual intensity ray of the tested liquid article of transmission, obtain simulating signal, and analog signal conversion is become digital signal, thereby the dispensing liquid article are for the scan-data of sigmatron and low energy X ray; Controller 50, it is used 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, are used 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 the data output cable of being connected with harvester and be connected with computer data processor 60, according to trigger command, the data that gather are stored in computer data processor 60.

In addition, checkout facility also comprises the tubular object passage 20 that is 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 gather of data acquisition unit 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 used in the temporary various data of processor 66 courses of work.In addition, also store in storer 61 be used to the computer program that carries out the data processing and database prepared in advance, this database stores the relevant information of various known liquid articles, information such as liquid title, kind and physical attribute, the property value such as density and atomic number that is used for the tested liquid article liquid that calculates with processor 66 compares.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 the operational order of 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 display device 67 such as LCD display, perhaps directly with the formal output result of 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 is used for producing the trigger command of the action that is 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 at the trigger command that produces according to trigger pip generation unit 52 and rises or descend under the control of control module 51; 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, it drives load carrier 40 rotations at the trigger command that produces according to trigger pip generation unit 52 under the control of control module 51; Angle information acquiring unit 54, it obtains the anglec of rotation of load carrier 40 in load carrier 40 rotary courses, feed 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.

As mentioned above, store database in storer 61, wherein stored identification information and the physical property values of known various liquid articles with tree structure, for example the reference density of liquid article and referencing atom ordinal number.Fig. 4 shows the identification information of the various liquid articles of storage in database and the structure that attribute information adopts.

For example at first all samples are divided into some subclasses, such as subclass 1 (wine), subclass 2 (cola), subclass 3 (milk) ... subclass n etc.Then, each subclass is subdivided into some subclasses.For example subclass 1 (wine) is subdivided into subclass 1.1 (grape wine), subclass 1.2 (Spirit), subclass 1.3 (beer) ..., subclass 1.n etc.Each subclass continues segmentation.Such as, subclass 1.2 (Spirit) be subdivided into subclass 1.2.1 (Rum), subclass 1.2.2 (whiskey), subclass 1.2.3 (vodka) ..., subclass 1.2.n (China white wine), until the difference of the reference density of inner each sample of subclass and atomic number is less than the value of a certain appointment, scope such as the systematic survey noise, no longer segmentation, this group becomes the leaf node of attribute structure.

In addition, each leaf node identifies with the combination of its all father node titles, such as " Cuba produces 40 degree Havana anejo Rums ".This sign and reference density and referencing atom ordinal number are one to one.In check process, computing machine shows the user step by step with tree structure, and the operator inputs identification information by the mode of selecting step by step.Such as, operator wishes to obtain the physical attribute information that one bottle of Cuba produces 40 degree Havana anejo Rums, can along wine-＞Spirit-＞Rum-＞Cuba's Rum-＞path of Havana anejo Rum-＞40 degree is selected step by step.

The operator by selecting step by step the process of input sign, is also the process of computer search simultaneously, and when the user determined final sign, its corresponding reference density and atomic number also were retrieved simultaneously.

Fig. 5 is the schematic diagram for the relation of explanation DR imaging and CT imaging.First embodiment of the 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 that checks.

Fig. 6 and Fig. 7 show respectively the example of DR imaging.As shown in Figure 6, after certain liquid article is carried out the DR imaging, by the position that pixel value analysis is judged liquid in liquid article as described below.As shown in Figure 6, only comprise a kind of liquid in this liquid article.But, as shown in Figure 7, because different liquids is different to the absorption coefficient of liquid, when liquid article comprises two kinds or two or more liquid, and when layering occurring in liquid, judge interfacial position between liquid by the DR image that obtains after the DR imaging being carried out pixel analysis.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, need to carry out safety inspection to the liquid article that the passenger carries.At first at step S110, the operator is placed on tested liquid article on load carrier 40, and the identification information that obtains this liquid article according to passenger's customs declaration or the label on liquid article, for example 40 degree rum.

Then, at step S111, the operator searches for from database according to this identification information and obtains its reference density and referencing atom ordinal number.Next, the operator presses start button and begins to carry out DR scanning, to generate the DR image, as shown in Fig. 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.The 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 not scan to guide CT scan by DR, but directly CT scan is carried out in predetermined some positions.Such as, through investigation, as can be known at the distance bottle end 5 centimetres carry out CT scan the time, can be checked through the liquid position of most of liquid commodity, can use at the bottom of the bottle height of 5 centimetres 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 (as the position of arrow indication in Fig. 6 and Fig. 7) of CT imaging, perhaps at step S113B, specify by the input media 65 of operator's operation such as mouse 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, do not checked on the quality and can not reduce.

After the position of having determined CT scan, carry out the CT scan process at step S114, namely carry out CT scan for above-mentioned definite scanning position liquid towards article, 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, the density measured and atomic number and the reference density of retrieving from database and atomic number are compared, judge both whether consistent with each otherly, for example whether both difference is less than the threshold value of being scheduled to.At step S117, if difference shows that greater than predetermined threshold value this liquid article is suspicious, send warning to the operator, perhaps print 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 S210,50 send order from computing machine 60 to controller, to drive load carrier 40 along 20 vertical movements of object passage.Controller 50 is in the process of load carrier vertical movement, by the height of elevation information acquiring unit 53 Real Time Monitoring load carriers.

At step S211, controller 50 is given every certain height (such as 1 millimeter) and is surveyed and trigger pip of harvester 30 transmissions.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 that collects from detection and harvester 30, be arranged as the form of data matrix, becomes the DR image.Each pixel of DR image has recorded ray and has 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 is all at first to obtain a line number on the DR image, and then computing machine is converted to the load carrier height with this line number, and after instruction control unit 50 drives load carriers 40 and move to assigned address, then carry out the CT imaging.

By DR imaging flow process as can be known, every delegation of DR image is corresponding to specific load carrier 40 height.When supposing that the DR imaging process begins, the load carrier height value is 0, and in imaging process, load carrier constantly descends, and triggers once gathering every the h millimeter, and the m in the DR image is capable so, and its corresponding load carrier height is-m*h.

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

At step S310, the high low energy data of DR image are merged and level and smooth, obtain the less monodrome DR image of noise.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 filtering to image to process.

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 the pixel below threshold value is classified as foreground pixel at this with value, 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 delegation 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 delegation is classified as horizontal edge capable.

At step S314, the DR image is carried out 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 got rid of less than the zone of a certain threshold value.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 might being bottle, between bottle cap or liquid in container and container top.Determining of concrete threshold value can be determined 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 got rid of less than the zone of certain threshold value.These zones are often corresponding to elongated bottleneck.Determining of concrete threshold value can be determined by the width that various liquid package container bottlenecks are obtained in realization.

At step S315, determine the CT scan position of liquid regions (may have a plurality of), complete the Hierarchical Location of liquid.Behind eliminating 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 by input media 65 on the DR image that shows directly appointment to carry out the row of CT scan, 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 for controller 50, drives load carrier 40 rotation predetermined angulars, for example 1 degree.Controller 50 is in the process that load carrier rotatablely moves, by angle information acquiring unit 54 Real Time Monitoring load carrier angles.

At step S411, when turning over 1 degree, controller 50 is given and is surveyed and 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 a week.If do not reach a week, flow process forwards step S410 to, continues above-mentioned operating process.

If after the accumulative total rotational angle reached specified angle (such as 360 degree), rotatablely moving at step S413 stopped, 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 that collects from detection and harvester 30, be 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 has recorded ray and has 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 the density and the atomic number image that obtain on tomography, i.e. the CT image.Each pixel in the CT image has recorded tested object at density and the atomic number of 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 line integral along certain direction θ, just obtain the function p of one dimension _θ(t), this function is called u (x, y) in the projection of θ angle.If can access the projection p of all directions _θ(t), can obtain Two dimensional Distribution u (x, y) according to Radon conversion accurate Calculation so.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 the related energy range of small-sized X-ray safety inspection system (＜200keV), the material line attenuation coefficient can come approximate representation with following analytical expression (1).

μ(E)＝a ₁f _p(E)+a ₂f _KN(E) (1)

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

$a_2=\frac{\mathrm{\ρZ}}{M}---\left(3\right)$

In formula (1), f _p(E) expression photoelectric effect cross section is along with the variation relation of energy, f _KN(E) expression Compton scattering cross section is along with the variation of energy, f _p(E) and f _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 represents atomic number, and M represents mass number, and ρ represents density (g/cm ³), n is constant.

Because the line attenuation coefficient of every kind of material can be by two coefficient a in formula (1) ₁And a ₂Uniquely determine, therefore can choose two kinds of sills, such as carbon and aluminium, represent 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, μ (E) is the line attenuation coefficient of any one material, μ ₁(E) and μ 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.

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

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:

${\mathrm{\&rho;}}^{*}={\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&rho;}}_1^{*}+b_2{\mathrm{\&rho;}}_2^{*}---\left(6\right)$

$Z={\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&rho;}}_1^{*}{Z}_1^n+b_2{\mathrm{\&rho;}}_2^{*}{Z}_2^{\mathrm{<figure-callout\; id="1"\; label="n\; b"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">n</figure-callout>}}}{b_{}}\right)}^{1/n}---\left(7\right)$

● 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 with 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 ₀Represent respectively ray by before object decay and the detector readings value after decay, E with I _mThe ceiling capacity of expression ray, l represents 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 represent μ (x, y) along the line integral of certain straight line, thereby does not satisfy the requirement of CT mathematical principle.Conventional reconstruction algorithm is ignored this inconsistency, rebuilds the pseudo-shadow that μ (x, the y) image that obtains contains cup-shaped, is called the pseudo-shadow of sclerosis.

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:

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

The integration along path l in following formula is expressed with following formula:

∫ _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 ₂Be 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 according to the CT reconstruction theory and obtain sill coefficient b 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.

● finding the solution of sill coefficient projection

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

$p_1({\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1,B_2)=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(13\right)$

$p_2({\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1,B_2)=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(14\right)$

Measuring (p ₁, p ₂) after, can find the solution according to equation (13) and (14) and obtain (B 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.

Noticing, is d when ray passes thickness ₁And d ₂Sill 1 and 2 after, the dual intensity projection that measures such as following expression formula:

${\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">p</figure-callout>}}_1=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">d</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(15\right)$

$p_2=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HSA00000409184300161.png"\; state="\{\{state\}\}">d</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(16\right)$

Contrast (13), (14) and (15), (16) can find out, the data for projection of supposing to measure is to (p ₁, p ₂) identical, the sill data for projection is to (B so ₁, B ₂) with the thickness of sill combination (d 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 less monodrome CT image of noise.The concrete grammar that merges 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 filtering to image to process.

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 the pixel more than threshold value is classified as foreground pixel at this with value, 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 bianry image corresponding to CT figure, and the value of foreground pixel is 1, the value of background pixel is 0; Then this bianry image is carried out repeatedly erosion operation, corrode a pixel at every turn, value is that 1 pixel is the liquid pixel at last.This is because liquid always in the inside of packing material, can be removed packing material step by step by repeatedly corroding.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 are 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 liquid is suspicious.Finally, report final check result to the operator.

In addition, exist the liquid article information in database not enough, the situation that need to expand.In other words, the every data content in database can be filled by supplier before system dispatches from the factory by producer, also allows that the operator expands database after system dispatches from the factory simultaneously.For example in the situation that a kind of new beverage has appearred in the market, the operator can be from reference density and the referencing atom ordinal number of this beverage of Sample producing of this beverage.Figure 15 shows the process that database is expanded.

The basic skills of filling a record in database is: at first survey test sample and determine its reference density and atomic number, then set up a unique sign at tree-shaped tag system for it, and sign, reference density and atomic number are deposited in database together according to sign.

As shown in figure 15, at step S610, the operator powers on to system, and the log database Expansion Interface.Enter ready state after System self-test.The operator is placed on the fluid sample that hope is added in database on load carrier 40.At step S611,50 give an order from computing machine 60 to controller, trigger radiographic source 10 and detection and harvester 30 and carry out the DR imaging, and step S612A as described above mode automatically determine liquid position or also can manually specify liquid position on DR figure step S612B operator.

At step S613, carry out the CT imaging at automatic or manual definite liquid position, and analyze the CT image with reference density and atomic number from CT Image Acquisition liquid at step S614.

Then, at step S615, the operator sets a sign to fluid sample, such as Coca-Cola, then after step S616 is with fluid identification and its reference density and atomic number binding, is saved in database.

[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 detects simultaneously many liquid articles in detail below in conjunction with Figure 16～19.The difference of the second embodiment and the first embodiment is, because there are many liquid articles, need to be after the CT imaging be completed, the position of the object on the position of the imaging results that shows on display and load carrier is corresponding, thereby convenient operation person understands fully that part liquid article is suspicious.Figure 16 A and Figure 16 B show the schematic diagram of the CT image of rebuilding in situation according to many liquid articles of detection of second embodiment of the invention.

For example, the operator observes checking matter on load carrier in the mode of overlooking, and after this just requires to check and finishes, on each layer CT image, the position of each object must be consistent with load carrier 40 vertical views.

Figure 17 A-17K shows after the CT imaging is completed, and how CT reconstructed image and/or load carrier is rotated its process consistent with the relative position of object before CT scan that make.

Figure 17 A shows when CT imaging for the first time begins, and the vertical view of load carrier 40 is wherein with the angle of arrow indication load carrier.Figure 17 B shows the CT image before CT image rotation for the first time, and the vertical view of its load carrier when imaging begins for the first time is consistent, the rotating range of dotted line sign load carrier wherein.Figure 17 C shows the image after ground floor CT image rotation, because the anglec of rotation is zero, therefore in fact need not this layer CT image is rotated.

Figure 17 D shows when the n time CT imaging begins, the vertical view of load carrier.Can find out from Figure 17 D, when the n time CT imaging begins, the situation of load carrier before the CT imaging for the first time, with an angle.Figure 17 E shows the image before the n time CT image rotation, and when it begins with the n time imaging, the vertical view of load carrier is consistent.Figure 17 F shows the image in Figure 17 D is rotated, and makes the schematic diagram of itself and ground floor CT image alignment.

Figure 17 G shows when the CT imaging begins the last time, the vertical view of load carrier, the load carrier that can find out this moment when beginning than CT imaging for the first time with an angle.Figure 17 H shows the image before the N time CT image rotation, and when it begins with the N time imaging, the vertical view of load carrier is consistent.Figure 17 I shows the image in Figure 17 H is rotated, and makes the schematic diagram of itself and ground floor CT image alignment.

After Figure 17 J shows last CT imaging end, the vertical view of load carrier, the situation before wherein beginning than CT imaging for the first time has an anglec of rotation.Figure 17 K shows after imaging finishes, load carrier to be rotated and makes it consistent with the image that CT imaging for the first time obtains.

After all CT imaging processes finish, each layer CT image and load carrier are carried out angular setting one time.At first, load carrier angle when imaging begins according to each time CT (this angle can obtain by angle information acquiring unit 54), each layer CT image is rotated processing, the position of same object in each layer 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 begins, the load carrier angle is α _n, during end, the load carrier angle is β _n, load carrier is counterclockwise to rotate on vertical view.For the position on all with the 1st layer, the position of object in n layer CT image is consistent, only need n layer CT image by anglec of rotation α counterclockwise _n-α ₁Get final product.After image rotating, be consistent at load carrier vertical view and CT figure in order to make object, only need load carrier by counter clockwise direction anglec of rotation 360-(β _N-α ₁) get final product.

Figure 18 shows in the situation that many process flow diagrams that tested object checks.As shown in figure 18, at step S710, the operator powers on to system, and login checks and to enter ready state after System self-test in the interface.Then, the operator is with 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.In addition, the operator inputs object A and object B identification information separately.

At step S711, retrieve separately reference density and referencing atom ordinal number based on the identification information of object A and object B from database.Next, at step S712, the operator presses start button and begins according to carrying out DR scanning with identical as mentioned above mode, 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, perhaps at step S713B, specify by the input media 65 of operator's operation such as mouse 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, do not checked on the quality and can not reduce.

After the position of having determined CT scan, carry out the CT scan process at step S714, namely carry out CT scan for above-mentioned definite position liquid towards article, 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.Exist when liquid in the situation of multilayer, carry out CT scan for each layer.

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

At step S717, every layer of CT image carried out image segmentation process (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, compare with reference density and atomic number at step S719 and with it, whether suspiciously differentiate this layer liquid of this part checking matter at step S720 accordingly.

At step S721, gather each layer inspection conclusion and be prompted to the operator.A kind of method of summary is: only when in all CT images, all liq zone all was judged to safe liquid, the conclusion of this inspection was " safety "; Otherwise the conclusion of this inspection is " suspicious ".In addition, every layer of CT image carried out colorize process and be shown to the user, the checking matter that is judged to suspicious object in CT figure uses 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 checks simultaneously 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 19, mark off a plurality of zones on surface to load carrier carrying liquid article, for example the A district in Figure 19, B district, C district and D district, operating personnel can be placed on each part liquid article in corresponding zone like this, and input separately fluid identification information for regional.

[the 3rd embodiment]

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

Therefore, the difference of the 3rd embodiment and the second embodiment is, has used the lattice bucket in the process that checks many objects.Describe specific operation process according to the checkout equipment of present embodiment in detail below in conjunction with accompanying drawing 20～25.

Figure 20 shows the side view according to the lattice bucket of present embodiment, and Figure 21 shows the vertical view of lattice bucket, and Figure 22 shows the backplan of lattice bucket.

As shown in figure 20, lattice bucket 70 comprises bottom and the sidewall that is coupled with the 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 both.

In addition, as shown in figure 20, be provided with flange in one week of top of sidewall, 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 21 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 that is formed by bottom and sidewall, this space is divided into a plurality of spaces as required, be respectively used to place liquid article.Like this, in the time will detecting many liquid articles simultaneously, these many liquid articles are placed on respectively in the space of being divided by the lattice parts, these liquid articles are detected simultaneously.In this case, can on the outside surface of sidewall, mark be set, be convenient to when detecting inspection instrument in the location of article.For example, having one bottle when suspicious in four article being detected, can according to the relative position of these part article with respect to the mark that arranges on sidewall, be which part article is suspicious to user report.

For example, as shown in the left hand view of Figure 21, be provided with at the upside of lattice parts the mark that the cross section is the circle of preliminary dimension, perhaps other little of the Length Ratio of certain lattice parts is thus as location liquid article mark used.

Figure 22 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 23 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.Take with the first bucket of cross lattice as example, step S810 can model one width with the template image of cross, and the center of this template is placed in CT picture centre to be identified, obtain matching value.

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

If there is the lattice cylinder in CT figure, can further come the detection and location mark according to specifically labelled characteristics at step S812.Still take with the first cylinder of cross lattice as example, 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 to have the lattice cylinder in CT figure, the 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 the detection of lattice cylinder and telltale mark detection.If the lattice cylinder all do not detected in each layer CT image, think that the operator does not use the lattice cylinder; If the lattice cylinder detected in one deck CT image at least, think that the operator has used the lattice cylinder; If differ in each layer detects telltale mark position, wherein the signal intensity maximum final telltale mark of conduct.Describe that in certain one deck CT, a method of telltale mark signal intensity is: the maximal value with four cut-off rule length of this layer deducts mean value, and its difference is larger, and the telltale mark signal is stronger.

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

As shown in Figure 24 A and 24B, with angle of lattice bucket rotation, to reach the position that requires in advance.Equally, every layer of resulting image of CT imaging is rotated, makes its angle with postrotational lattice bucket consistent.

Figure 25 shows the process flow diagram according to the checking process of present embodiment.Because the step S710 with above-mentioned the 3rd embodiment is identical to step S721 from step S910 to step S921, step S922 is only described to step S926. here

At step S922, analyze the CT image, whether detect cylinder with lattice 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 CT image angle are adjusted for the second time, will be detected the position of each lattice in cylinder on load carrier, and the position of each lattice on each layer of liquid CT image, all adjust on preposition.

At step S926, system lists the check result that drops on each liquid regions in each lattice part in every layer of CT image, 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 when dropping in all CT images that in this lattice, 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 ".

[the 4th embodiment]

The first to the 3rd above embodiment has been described inspection method of the present invention and has been used for judging whether tested liquid article is suspicious object, but can judge directly also whether tested liquid article has hidden drugs.

The physical attribute of liquid (such as density and equivalent atom ordinal number) will change after hiding poison.Such as, the density of pure water is 1.00g/cm ³, atomic number is 7.5.

When being dissolved with the 50g cocaine in 1000g water, its density becomes 1.01g/cm ³, atomic number is 7.6.

The method of substance for calculation (comprising potpourri) equivalent atom ordinal number is as follows:

Suppose that certain material contains N kind element altogether, various Atom of Elements are respectively Z _i, atom number number percent is α _i, i=1 wherein, 2 ..., N, and

The equivalent atom ordinal number of this material is so:

$Z_{\mathrm{eff}}={[\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i{Z_i}^{4.5}/\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i{Z}_i]}^{\frac{1}{3.5}}$

Like this, with water (H ₂O) be example, the computation process of its equivalent atom ordinal number is as shown in table 1 below:

The variation of density, atomic number after the poison of liquid Tibetan (dissolving cocainehydrochloride as example in water) is as shown in table 2 below:

In addition, Figure 26 A is the change curve of explanation liquid density after having hidden drugs.Figure 26 B is the change curve of explanation liquid atomic number after having hidden drugs.Figure 26 C is the change curve of explanation liquid characteristic density after having hidden drugs.

The below's contrast accompanying drawing 27 describes the inspection method of embodiment of the present invention in detail.

At step S1010, the operator is placed on tested liquid article on load carrier 40, and the identification information that obtains this liquid article according to passenger's customs declaration or the label on liquid article, for example one bottle of water.

Then, at step S1011, the operator searches for from database according to this identification information and obtains its reference density and referencing atom ordinal number, and for example density is 1.00 (characteristic density 1.11) g/cm ³, the referencing atom ordinal number is 7.51.Next, the operator presses start button and begins to carry out DR scanning, to generate the DR image.

After obtaining the DR image, at step S1013A, the DR image is analyzed, automatically determine the scanning position of CT imaging, perhaps at step S1013B, specify by the input media 65 of operator's operation such as mouse 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, do not checked on the quality and can not reduce.

After the position of having determined CT scan, carry out the CT scan process at step S1014, namely carry out CT scan for above-mentioned definite scanning position liquid towards article, 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 S1015, computing machine is analyzed the CT image by execution analyzer, obtains density and the atomic number of measurement, and for example recording its density is 1.02 (characteristic density 1.13) g/cm ³, atomic number 7.71.And then, at step S1016, by can be calculated actual density and reference value differs 0.02g/cm ³, atomic number differs 0.20.Be set as density difference 0.01g/cm if hide malicious discrimination threshold ³, atomic number differs from 0.10, within the density of measuring so and atomic number have dropped on predetermined scope.At step S1017, if difference shows that greater than predetermined threshold value this liquid article is suspicious, send warning to the operator, perhaps print check result.

Differentiate required reference density and atomic number, can measure in advance a sample of this class I liquid I, and be saved in database.Differentiate required difference threshold value, can manually be set as a suitable value.If wish to detect the drugs of trace, this threshold value can be made as smaller value; Its risk is, even do not hide the checking matter of poison, also may record a larger deviate because of the reason of system noise, thereby cause wrong report.Otherwise, if wish to reduce as much as possible for not hiding the wrong report of venom body, threshold value should be made as higher value; Its risk is, if tested liquid keeps a small amount of drugs, its density variation is not enough to reach discrimination threshold, will cause failing to report.

Although abovely be illustrated as an example of single inspection object example, as those of ordinary skill in the art institute clearly, the method for the 4th embodiment can be applied to many bottles of detections equally as the second embodiment and the 3rd embodiment.

[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 and come the liquid towards article to check.

The liquid towards article carry out spiral CT and check that resulting is one group of spiral CT image, by relatively and analyze 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 position, for example density and atomic number.For example when as shown in figure 28 liquid article is carried out the spiral CT imaging, if scan take 2cm as screw pitch, will obtain one group of CT image as shown in Figure 29 A-29M.Like this, by analyzing the pixel value in each spiral CT image, the position that just can learn liquid in liquid article.The spiral CT imaging here can be adopted coarse pitch CT imaging or conventional pitch CT imaging.

In addition, although toply be illustrated as an example of density and atomic number example, the present invention can only carry out with one of density or atomic number equally, perhaps carries out with other more physical attributes.

[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 only is used for realizing embodiments of the present invention; it should be appreciated by those skilled in the art; the any modification or partial replacement that is not departing from the scope of the present invention; all should belong to claim of the present invention and come restricted portion; therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.

Claims (40)

1. One kind with dual intensity CT to the method that a plurality of liquid articles check simultaneously, comprise step:

   In a plurality of positions, tested liquid article is carried out the dual intensity CT scan, obtain dual intensity CT data for projection, after wherein carrying out the dual intensity CT scan for each position, the CT image of the tested liquid article of rotation makes the formed image alignment of Multiple-Scan;

   Carry out CT according to described data for projection and rebuild, obtain representing 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

   Reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is suspicious.
2. 2. the method for claim 1, wherein said physical property values comprises density and the atomic number of tested liquid article.
3. 3. the method for claim 1, wherein said dual intensity CT scan adopts the mode of plane fault CT scan.
4. 4. the method for claim 1, wherein said dual intensity CT scan adopts the mode of conventional Spiral CT scan.
5. 5. the method for claim 1, wherein said dual intensity CT scan adopts the mode of screw with long screw pitch CT scan.
6. 6. method as claimed in claim 3 before carrying out the plane fault CT scan, presets the CT scan position.
7. 7. method as claimed in claim 3 before carrying out the plane fault CT scan, is first carried out the transmission image that DR scanning obtains tested liquid article, then determines the CT scan position according to transmission image.
8. 8. method as claimed in claim 7, after obtaining transmission image, the operator specifies delegation at least in transmission image by input media, as the CT scan position.
9. 9. method as claimed in claim 7 after obtaining transmission image, is determined delegation at least in transmission image by image processing techniques, automatically as the CT scan position.
10. 10. method as claimed in claim 7, the step that wherein obtains transmission image comprises:

    Send high-energy ray and low energy ray from radiographic source, penetrate tested liquid article, form high energy transmission image and low energy transmission image;

    Merge high energy transmission image and low energy transmission image, form described transmission image.
11. 11. method as claimed in claim 7, the step that wherein obtains transmission image comprises:

    Send high-energy ray and low energy ray from radiographic source, penetrate tested liquid article, 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.
12. 12. the method for claim 1 is wherein carried out CT according to described data for projection and is rebuild, and obtains representing that the step of CT image of the physical property values of tested liquid article 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, obtain representing the CT image of the corresponding two kinds of sill coefficients of tested liquid article; And

    According to the CT image of the corresponding two kinds of sill coefficients of the tested liquid article of expression, generate the CT image of the tested liquid article physical property values of described expression.
13. 13. the method for claim 1 wherein comprises according to the step that described CT image extracts the physical property values of tested liquid article:

    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.
14. 14. method as claimed in claim 13, wherein the reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is that suspicious step comprises:

    Calculate the density of described tested liquid article and atomic number and reference density and the atomic number difference between separately;

    In the situation that greater than predetermined threshold value, thinking, described difference hidden drugs in described tested liquid article.
15. 15. the method for claim 1, wherein after carrying out the dual intensity CT scan for each position, the CT image of the tested liquid article of rotation makes itself and the formed image alignment of dual intensity CT scan for the first time.
16. 16. method as claimed in claim 15 wherein after carrying out the dual intensity CT scan for each row, is rotated tested liquid article, makes it identical with the position before scanning.
17. 17. the method for claim 1, wherein said tested liquid article are placed in the bucket that has been divided into a plurality of spaces.
18. 18. method as claimed in claim 17 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.
19. 19. method as described in claim 16 or 18 also comprises step:

    With the judgment result displays of tested liquid article on display screen.
20. 20. method as described in claim 16 or 18 also comprises step:

    The judged result of each tested liquid article is printed.
21. 21. method as described in claim 16 or 18 also comprises step:

    CT image color with each tested liquid article.
22. 22. one kind with dual intensity CT to the equipment that a plurality of liquid articles check simultaneously, comprising:

    Radiographic source is used for sending ray;

    Survey and harvester, be used for surveying and gathering the ray signal that penetrates at least one tested liquid article;

    Controller, control described radiographic source and detection and harvester and in a plurality of positions, tested liquid article is carried out the dual intensity CT scan, obtain data for projection, after wherein carrying out the dual intensity CT scan for each position, rotate the CT image of tested liquid article, make the formed image alignment of Multiple-Scan;

    Rebuild the device of the CT image of the physical property values that represents tested liquid article from data for projection; And

    Reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is suspicious device.
23. 23. being based on preposition, equipment as claimed in claim 22, described dual intensity CT scan carries out.
24. 24. the ray signal that penetrates at least one tested liquid article is surveyed and gathered to equipment as claimed in claim 22, wherein said detection and harvester to form transmission image;

    Wherein said equipment also comprises the device of specifying the delegation at least in transmission image;

    Described dual intensity CT scan is based on specified going and carries out.
25. 25. equipment as claimed in claim 22, wherein said physical property values comprise density and the atomic number of tested liquid article at least.
26. 26. equipment as claimed in claim 24 wherein sends high-energy ray and low energy ray from radiographic source, penetrates tested object, forms 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.
27. 27. equipment as claimed in claim 24 wherein sends high-energy ray and low energy ray from radiographic source, penetrates tested object, forms 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.
28. 28. equipment as claimed in claim 24, the device of the delegation at least in described appointment transmission image comprises:

    The operator utilizes input media to select the device of delegation at least from transmission image.
29. 29. equipment as claimed in claim 24, the device of the delegation at least in wherein said appointment transmission image comprises:

    Analyze the pixel value of described transmission image, with the device with described transmission image layering;

    Middle row in each layer is appointed as the device that will carry out the row of dual intensity CT scan.
30. 30. equipment as claimed in claim 24 wherein comprises from the device of CT image that data for projection is rebuild the physical property values of the tested liquid article of expression:

    The density image that fusion is identified by the density of tested liquid article and the atomic number image that identified by the atomic number of tested liquid article are as the device of described CT image;

    Extract the device of 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.
31. 31. equipment as claimed in claim 30, wherein the reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is that suspicious device comprises:

    Calculate the device of the density of described tested liquid article and atomic number and reference density and the atomic number difference between separately; In the situation that greater than predetermined threshold value, thinking, described difference hidden drugs in described tested liquid article.
32. 32. equipment as claimed in claim 24 also comprises: after carrying out the dual intensity CT scan for every row, the CT image of the tested liquid article of rotation makes itself and the device of the formed image alignment of dual intensity CT scan for the first time.
33. 33. equipment as claimed in claim 24, also be included in carry out the dual intensity CT scan for each row after, rotate tested liquid article, make the identical device in position before itself and scanning.
34. 34. equipment as claimed in claim 24 also comprises bucket, has been divided into a plurality of spaces, is respectively used to place described liquid article.
35. 35. equipment as claimed in claim 34 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.
36. 36. equipment as described in claim 33 or 35 also comprises:

    Display device, the judged result of the tested liquid article of demonstration.
37. 37. equipment as described in claim 33 or 35 also comprises:

    The device that the judged result of each tested liquid article is printed.
38. 38. equipment as described in claim 33 or 35 also comprises:

    Device with the CT image color of each tested liquid article.
39. 39. equipment as claimed in claim 24 also comprises the load carrier that carries described tested liquid article, is divided into the discernible a plurality of zones of operating personnel on the surface of the described tested liquid article of described load carrier carrying.
40. 40. equipment as claimed in claim 35, also comprise the load carrier that carries described tested liquid article, on the surface of the described bucket of described load carrier carrying, a plurality of pilot holes are arranged, make the projection of described bottom of the barrel can be inserted in pilot hole corresponding on load carrier.

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