CN102147376B - Liquid article detection method and device - Google Patents

Abstract

The invention discloses a method for detecting a liquid article by using a double-energy spiral CT (captive test) and a device. The device comprises a ray source, a detecting and collecting device, a load bearing mechanism, a controller and a computer, wherein the ray source is used for emitting high-energy and low-energy X rays; the detecting and collecting device is used for detecting and collecting the high-energy and low-energy X rays which penetrate through at least one detected liquid article; the load bearing mechanism can bear the detected liquid article to rotate around a shaft and can move up and down so that the detected liquid article enters a detection area, thereby leading the high-energy and low-energy X rays emitted by the ray source to penetrate through the tested liquid article; the controller controls the ray source and the detecting and collecting device to carry out double-energy spiral CT scanning on the detected liquid article so as to form a group of spiral CT images which respectively represent at least one physical attribute value of the detected liquid article; and the computer analyzes the group of spiral CT images so as to determine the spiral CT image part of liquid and judges whether the detected liquid article is suspicious based on the physical attribute value and the reference physical attribute value of the liquid article. The method can quickly detect the liquid article.

Description

Liquid article examination method and equipment

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

Background technology

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

Current, have the method for following four classes can be for the safety inspection of liquid article: chemical method, electromagnetic method, middle 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 cannot be realized inspection because of the sealed packing of liquid article in actual applications.Ion scan is surveyed famous with hypersensitivity, but its shortcoming is that rate of false alarm is high, is usually subject to the impact of background environment.Species analysis has precision height and the high feature of accuracy, but this method needs the regular hour to analyze sample, can not meet the on-the-spot demand checking fast.

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

3) use of neutron inspection method there will be the phenomenon of " neutron activation ", and the liquid article that is examined through neutron inspection has 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 cannot judge in liquid, whether to keep drugs; This is that just composition changes because keep after drugs in liquid, and obvious variation can't occur general structure.

In sum, for liquid article, check fast, chemical method, electromagnetic method and middle submethod exist the feature that itself is not suitable for fast and safely checking, adopt X ray two-dimensional imaging technology and three-D CT scanning imaging technique, can only obtain the image that comprises 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 object of this invention is to provide a kind of method and apparatus with safety-checking liquid stage article with ray, it can check fast it, obtain being examined the quantitative information of liquid article in the situation that not destroying liquid article packing.

In one aspect of the invention, proposed a kind of equipment checking with dual intensity spiral CT liquid towards article, having comprised: radiographic source, for sending high energy and low energy X ray; Survey and harvester, for surveying and gather high energy and the low energy X ray that penetrates at least one tested liquid article; Load carrier, carries tested liquid article and encloses and sway, and can lifting, make tested liquid article enter surveyed area, thereby the high energy being sent by radiographic source and low energy ray can see through tested liquid article; Controller, controls described radiographic source and detection and harvester tested liquid article is carried out to dual intensity Spiral CT scan, forms one group of spiral CT image of each at least one physical property values that all represents tested liquid article; Computing machine, analyzes this group spiral CT image to determine the spiral CT image section of liquid, and the reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is suspicious.

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

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

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

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

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

According to embodiments of the invention, described computing machine has database, and this database stores the relevant information of various known liquid articles, for comparing with the property value of tested liquid article liquid.

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

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

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

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

According to embodiments of the invention, describedly with reference to physical property values, be stored in database, and described database is open-ended.

According to embodiments of the invention, in described database, fill a record and comprise: actual measurement test sample is determined its reference density and atomic number; At tree-shaped tag system, for it, set up a unique sign; And sign, reference density and atomic number are deposited in this database together with sign.

Utilize method and apparatus of the present invention, owing to adopting transmission image to carry out 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 measurement 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, operator can carry out dual intensity CT scan in the position of any appointment, has facilitated the carrying out of check operation.In addition, operator can need to add new tested class of liquids voluntarily according to concrete.

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

Accompanying drawing explanation

In 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 according to the structural representation of 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 according to the structured flowchart of the controller of first embodiment of the invention;

Fig. 4 shows and in database, stores the identification information of various liquid articles and the structure that attribute information adopts;

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

Fig. 6 shows an example of DR imaging results;

Fig. 7 shows another example of DR imaging results;

Fig. 8 shows according to the overview flow chart of 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 DR imaging process and to survey and the arrangement mode of the DR view data that harvester 30 gathers;

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

Figure 12 shows CT imaging process;

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

Figure 14 shows the process of measuring liquid attribute;

Figure 15 shows the process that database is expanded;

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

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

Figure 18 shows the process flow diagram checking the in the situation that of many tested objects;

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

Figure 20 shows according to the side view of 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 according to the process flow diagram of 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, with reference to accompanying drawing, describe the preferred embodiment of the present invention in detail.In the accompanying drawings, although be shown in different accompanying drawings, identical Reference numeral is 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 according to the structural representation of the checkout facility of embodiment of the present invention.

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

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

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

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

After operational order 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, be presented in the display device 67 such as LCD display, or the direct formal output result with hard copy such as printing.

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

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

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

For example 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 inner reference density of each sample of subclass and the difference of atomic number are less than the value of a certain appointment, scope such as 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 user step by step by tree structure, and operator inputs identification information by the mode of selecting step by step.Such as, operator wishes to obtain the physical attribute information that Yi Ping Cuba produces 40 degree Havana anejo Rums, can select step by step along the path of wine-> Spirit-> Rum-> Cuba Rum-> Havana anejo Rum-> 40 degree.

Operator, by selecting step by step the process of input sign, is also the process of computer search simultaneously, and when user determines final sign, its corresponding reference density and atomic number are also retrieved simultaneously.

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

Fig. 6 and Fig. 7 show respectively the example of DR imaging.As shown in Figure 6, after certain liquid article is carried out to DR imaging, by the as described below position that pixel value analysis is judged to liquid in liquid article.As shown in Figure 6, in this liquid article, only comprise a kind of liquid.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 while there is layering in liquid, by the DR image to obtaining after DR imaging, carry out pixel analysis and judge the interfacial position between liquid.Then, for different liquid, carry out CT imaging.

Fig. 8 shows according to the overview flow chart of the liquid article examination method of first embodiment of the invention.As shown in Figure 8, for example, during being open to the custom, the liquid article that need to carry passenger carries out safety inspection.First at step S110, operator is placed on tested liquid article on load carrier 40, and according to the label on passenger's customs declaration or liquid article, obtains the identification information of this liquid article, for example 40 degree rum.

Then, at step S111, operator searches for from database according to this identification information and obtains its reference density and referencing atom ordinal number.Next, operator presses start button and starts to carry out DR scanning, to generate DR image, as shown in Figures 6 and 7.

As mentioned above, the object of carrying out DR scanning is: the one, obtain the fluoroscopy images of tested liquid article, and make 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, user can specify the position that need to carry out CT imaging and inspection at DR image, guides next step CT imaging.After will describe the detailed process of DR imaging in detail.

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

After obtaining DR image, at step S113A, DR image is analyzed, automatically determine the scanning position (as the position of arrow indication in Fig. 6 and Fig. 7) of CT imaging, or at step S113B, the input media 65 by operator's operation such as mouse is specified the position that will carry out CT scan.Like this, because CT scan is carried out in representational position in liquid towards article only, thereby accelerated inspection speed, and can not reduce and check on the quality.

After having determined the position of CT scan, at step S114, carry out CT scan process, namely for above-mentioned definite scanning position liquid towards article, carry out CT scan, obtain 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 liquid article.

Then, at step S115, computing machine is analyzed CT image by execution analyzer, obtains density and the atomic number of measurement.And then, at step S116, the density of measuring and atomic number and the reference density of retrieving from database and atomic number are compared, judge that whether the two is consistent with each other, for example whether the difference of the two is less than predetermined threshold value.At step S117, if difference is greater than predetermined threshold value, show that this liquid article is suspicious, to operator, send warning, or print check result.

Below in conjunction with accompanying drawing 9～14, describe the detailed operating process of above-mentioned each step in detail.Fig. 9 shows the process flow diagram of DR imaging process, and Figure 10 shows in 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 DR imaging process, at step S210, from computing machine 60, to controller 50, send order, to drive load carrier 40 along 20 vertical movements of object passage.Controller 50, in the process of load carrier vertical movement, is monitored the height of load carrier in real time by elevation information acquiring unit 53.

At step S211, controller 50 is given and is surveyed and a trigger pip of harvester 30 transmissions every certain height (such as 1 millimeter).Detection and harvester 30 receive after this trigger pip, and the output signal of each detector is once gathered, and obtain high energy detection data and low energy detection data, and are 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 reached 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 collecting from detection and harvester 30, is arranged as the form of data matrix, becomes 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 DR image.No matter be to use the mode of identification automatically, or the mode of artificial appointment, is all first on DR image, to obtain a line number, and then computing machine is converted to load carrier height by this line number, and instruction control unit 50 drives load carriers 40 to move to after assigned address, then carry out CT imaging.

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

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

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

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

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

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

At step S313, extract level and smooth after horizontal edge in 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: the every a line to along continuous straight runs in DR image, the ratio of adding up its horizontal edge number of picture elements and foreground pixel number, if ratio arrives greatly certain threshold value above (such as 50%), is classified as horizontal edge by this line capable.

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

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

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

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

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

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

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

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

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

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

If accumulative total rotational angle reaches after specified angle (such as 360 degree), at step S413, rotatablely move and stop, controller 50 is no longer given and is surveyed and harvester 30 transmission trigger pips.Computing machine 60 reads the high low energy detector signal collecting from detection and harvester 30, is arranged as the form of data matrix, becomes 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 dual intensity reconstruction algorithm, according to high low energy CT data for projection, rebuilds and obtains density and the atomic number image on tomography, i.e. CT image.Each pixel in 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.

● CT mathematical principle

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

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

● sill decomposition model

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

μ(E)＝a ₁f _p(E)+a ₂f _KN(E) (1)

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

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

In formula (1), f _p(E) represent that photoelectric effect cross section is along with the variation relation of energy, f _kN(E) represent that Compton scattering cross section is along with the variation of energy, f _pand f (E) _kN(E) all there is known analytical expression.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, with the linear combination of the line attenuation coefficient of sill, represent other all materials, shown in (4):

μ(E)＝b ₁μ ₁(E)+b ₂μ ₂(E) (4)

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

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

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

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

with according to formula (1)～(4) above, can derive the atomic number of any one material so and the expression formula of characteristic density is as follows:

${\mathrm{\&rho;}}^{*}={\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&rho;}}_1^{*}+b_2{\mathrm{\&rho;}}_2^{*}---\left(6\right)$

$Z={\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&rho;}}_1^{*}{Z}_1^n+b_2{\mathrm{\&rho;}}_2^{*}{Z}_2^{\mathrm{<figure-callout\; id="1"\; label="n\; b"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">n</figure-callout>}}}{b_{}}\right)}^{1/n}---\left(7\right)$

● sill projection model

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

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

The expression formula of the projection value on a 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 the detector readings value that ray is decayed after front and decay by object, E with I _mthe ceiling capacity that represents 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 X ray pleochroism, formula (9) does not represent that μ (x, y) is along the line integral of certain straight line, thereby does not meet the requirement of CT mathematical principle.Conventional reconstruction algorithm is ignored this inconsistency, and the artifact that μ (x, the y) image that reconstruction obtains contains cup-shaped, is called sclerosis artifact.

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

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

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

Formula below the integration along path l in above formula is used is expressed:

∫ _lb ₁(x，y)dl＝B ₁ (11)

∫ _lb ₂(x，y)dl＝B ₂ (12)

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

● solving of sill coefficient projection

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

$p_1({\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1,B_2)=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(13\right)$

$p_2({\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1,B_2)=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">B</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(14\right)$

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

Notice, when ray is d through thickness ₁and d ₂sill 1 and 2 after, the dual intensity projection measuring is as expression formula below:

${\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">p</figure-callout>}}_1=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">d</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(15\right)$

$p_2=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HSA00000409183100122.png,HSA00000409183100161.png"\; state="\{\{state\}\}">d</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(16\right)$

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

Measure the dual intensity projection under different-thickness combination, just can obtain 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 liquid attribute.

As shown in figure 14, at step S510, density image and atomic number image are merged with level and smooth, obtain the monodrome CT image that noise is less.The concrete grammar merging 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 processing to image.

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

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

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

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

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 in the system Qian You supplier of dispatching from the factory by producer, also allows operator after system is dispatched from the factory to expand database simultaneously.For example, in the situation that a kind of new beverage has appearred in market, 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: first survey test sample and determine its reference density and atomic number, then at tree-shaped tag system, for it, set up a unique sign, and sign, reference density and atomic number are deposited in database together with sign.

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

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

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

[the second embodiment]

What the first embodiment was above described is the situation that at every turn detects single-piece liquid article, describes the operating process that simultaneously detects many liquid articles below in conjunction with Figure 16～19 in detail.The difference of the second embodiment and the first embodiment is, because there are many liquid articles, need to be after CT imaging completes, the position of the imaging results showing on display is corresponding with the position of object on load carrier, thereby convenient operation person understands fully that part liquid article is suspicious.Figure 16 A and Figure 16 B show according to the schematic diagram of the CT image of rebuilding in the situation of many liquid articles of detection of second embodiment of the invention.

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

Figure 17 A-17K shows after CT imaging completes, and how CT reconstruction image and/or load carrier is rotated to 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 starts, and the vertical view of load carrier 40, wherein by 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 starts is for the first time 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 without this layer of CT image is rotated.

Figure 17 D shows when the n time CT imaging starts, the vertical view of load carrier.From Figure 17 D, can find out, when the n time CT imaging starts, load carrier is than the situation before CT imaging for the first time, with an angle.Figure 17 E shows the image before the n time CT image rotation, and when it starts with the n time imaging, the vertical view of load carrier is consistent.Figure 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 CT imaging starts the last time, and the vertical view of load carrier can be found out when load carrier now starts than CT imaging for the first time with an angle.Figure 17 H shows the image before the N time CT image rotation, and when it starts with the N time imaging, the vertical view of load carrier is consistent.Figure 17 I shows the image in Figure 17 H is rotated, and makes the schematic diagram of itself and ground floor CT image alignment.

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

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

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

Figure 18 shows the process flow diagram checking the in the situation that of many tested objects.As shown in figure 18, at step S710, operator powers on to system, and login inspection interface, enters ready state after System self-test.Then, operator is by many checking matters, and for example object A and object B are placed directly on load carrier 40 and press 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, operator inputs object A and object B identification information separately.

At step S711, the identification information based on object A and object B is retrieved reference density and referencing atom ordinal number separately from database.Next, at step S712, operator presses start button and starts according to carrying out DR scanning with identical as mentioned above mode, to generate DR image.

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

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

At step S715 and S716, after last CT imaging finishes, method is adjusted load carrier angle and each layer of CT image angle as described above, the position of each object in each layer of CT image is consistent (such as alignment ground floor CT), 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 to image dividing processing (such as using watershed algorithm), obtain the wherein liquid regions of every checking matter, the density of each pixel and atomic number average in step S718 adds up each liquid regions, at step S719 and by it, compare with reference density and atomic number, whether suspiciously at step S720, differentiate this layer of liquid of this part checking matter accordingly.

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

Described above is the situation that simultaneously checks two liquid articles, in the time will checking more liquid articles simultaneously, for the ease of operating personnel, see the position of understanding each liquid article, as shown in figure 19, to marking off a plurality of regions on the surface of 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 region like this, and input fluid identification information separately for regional.

[the 3rd embodiment]

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

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

Figure 20 shows according to the side view of 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 being coupled with bottom.On the lower surface of bottom, be provided with the projection of a plurality of tapers or other shapes.These three tapered protrusion can be inserted in pilot hole corresponding on load carrier 40, thereby in load carrier rotary course, lattice bucket 70 rotates together with load carrier 40, prevents from producing relative motion between the two.

In addition, as shown in figure 20, at the top of sidewall, within one week, be provided with flange, handled easily person grasps and carrying.Sidewall is columned or taper, and can be by having 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, in the space being formed by bottom and sidewall, be provided with one or more lattice parts, 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, these many liquid articles are placed on respectively in the space of being divided by lattice parts simultaneously, these liquid articles are detected simultaneously.In this case, can on the outside surface of sidewall, mark be set, be convenient to when detecting inspection instrument in the location of article.For example, in four article being detected, have one bottle when suspicious, can be according to these part article the relative position with respect to the mark arranging on sidewall, to user report, be which part article is suspicious.

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

Figure 22 is the backplan of lattice bucket.On the lower surface of bottom, be evenly distributed with three projections.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, lattice cylinder has specific structure, and in can processing with image, the method for conventional stencil matching detects.The first bucket of take with cross lattice is example, step S810 can model one width with the template image of cross, and the center of this template is placed in to CT picture centre to be identified, obtain matching value.

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

If there is lattice cylinder in CT figure, can further according to specifically labelled feature, carry out detection and location mark at step S812.The first cylinder of still take with cross lattice is example, and its telltale mark is positioned at the top of a frame bar, makes this frame bar short compared with other three frame bars.Use template matching method to confirm to exist after lattice cylinder in CT figure, 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 multi-Slice CT imaging, first every one deck CT image is carried out to the detection of lattice cylinder and telltale mark detection.If lattice cylinder all do not detected in each layer of CT image, think that operator does not use lattice cylinder; If at least lattice cylinder detected in one deck CT image, think that operator has used lattice cylinder; If differ in the telltale mark position that each layer detects, signal intensity maximum final telltale mark of conduct wherein.Describing a method of telltale mark signal intensity in certain one deck CT is: by the maximal value of four cut-off rule length of this layer, deduct mean value, its difference is larger, and telltale mark signal is stronger.

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

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

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

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

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

At step S926, system is listed 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 user.According to a kind of method of summary of present embodiment, be: for certain lattice, only in all CT images, drop in this lattice when all liq region is all 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 also can directly judge 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.

While being dissolved with 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:

It is as shown in table 2 below that liquid is hidden the variation (take water in dissolve cocainehydrochloride as example) of density after poison, atomic number:

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.

Contrast the inspection method that accompanying drawing 27 describes embodiment of the present invention in detail below.

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

Then, at step S1011, 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, referencing atom ordinal number is 7.51.Next, operator presses start button and starts to carry out DR scanning, to generate DR image.

After obtaining DR image, at step S1013A, DR image is analyzed, automatically determine the scanning position of CT imaging, or at step S1013B, the input media 65 by operator's operation such as mouse is specified the position that will carry out CT scan.Like this, because CT scan is carried out in representational position in liquid towards article only, thereby accelerated inspection speed, and can not reduce and check on the quality.

After having determined the position of CT scan, at step S1014, carry out CT scan process, namely for above-mentioned definite scanning position liquid towards article, carry out CT scan, obtain 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 liquid article.

Then, at step S1015, computing machine is analyzed 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.If hide malicious discrimination threshold, be set as density difference 0.01g/cm 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 is greater than predetermined threshold value, show that this liquid article is suspicious, to operator, send warning, or 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 micro-drugs, this threshold value can be made as to smaller value; Its risk is, even do not hide malicious checking matter, 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 to 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 single inspection object of take above is illustrated as 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, first to carry out DR imaging, then carry out CT and be imaged as example embodiments of the invention are illustrated, also can directly carry out spiral CT imaging and come liquid towards article to check.

Liquid towards article carry out spiral CT and check that resulting is one group of spiral CT image, by relatively and analyze the pixel in this group CT image, just can determine the position of liquid in liquid article, and whether layering of liquid, then utilize with as described above similarly method obtain the physical property values of the liquid of each layer of position, for example density and atomic number.For example, when the liquid article to as shown in figure 28 carries out spiral CT imaging, if take 2cm as screw pitch scans, 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 adopt coarse pitch CT imaging or conventional pitch CT imaging.

In addition, although take density and atomic number above, be illustrated as example, the present invention can only carry out with one of density or atomic number equally, or is undertaken by other more physical attributes.

[modification 2]

Although above first to carry out DR imaging, then carry out dual intensity CT imaging and obtain density and the atomic number of liquid, but the DR imaging is here 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.

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

Claims (11)

1. the equipment checking with dual intensity spiral CT liquid towards article, comprising:

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

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

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

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

Computing machine, analyze this group spiral CT image to determine the spiral CT image section of liquid, and the reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is suspicious, wherein by relatively and analyze one group of pixel in spiral CT image and determine in this liquid article whether layering of liquid, then the liquid for each layer obtains corresponding physical property values.

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

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

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

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

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

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

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

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

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

5. equipment as claimed in claim 4, wherein said elevation information acquiring unit and angle information acquiring unit are all photoelectric code disks.

6. equipment as claimed in claim 1, wherein said computing machine has database, and this database stores the relevant information of various known liquid articles, for comparing with the property value of tested liquid article liquid.

7. the method checking with dual intensity spiral CT liquid towards article, comprising:

From radiographic source, send high energy and low energy X ray;

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

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

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

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

Reference physical property values based on described physical property values and this liquid article judges whether described tested liquid article is suspicious, wherein by relatively and analyze one group of pixel in spiral CT image and determine in this liquid article whether layering of liquid, then the liquid for each layer obtains corresponding physical property values.

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

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

10. method as claimed in claim 7, is wherein saidly stored in database with reference to physical property values, and described database is open-ended.

11. methods as claimed in claim 10, wherein in described database, fill a record and comprise:

Actual measurement test sample is determined its reference density and atomic number;

At tree-shaped tag system, for it, set up a unique sign; And

Sign, reference density and atomic number are deposited in this database together with sign.

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