CN101387611A - Translational pipe CT detection device and detection method thereof - Google Patents

Abstract

The invention discloses a translation type tube CT detector and a detection method thereof. The translation type tube CT detector comprises a ray generator, a data collector and a control and image processing system, wherein the ray generator and the data collector are connected with the control and image processing system. The translation type tube CT detector further comprises a translation mechanism comprising a guide rail and a slider, wherein the guide rail is parallel to an object tube and is fixed relatively, the slider is arranged on the guide rail in a horizontal fixation and longitudinal slide type, the ray generator and the data collector are fixed relatively to the slider at tow sides of the object tube. The invention is used to detect fixed tubes, which can synchronously scan and iterative reconstruction, to improve detection efficiency and improve object image quality. The translation type tube CT detector has compact structure, small volume and low production cost, and utilizes segment online rolling type multi-process parallel acceleration iterative reconstruction algorism to reconstruct sectional or three-dimension images, having the advantages of high detection speed, non-overlapped image, eliminated insertion of tubes and eliminated rotation.

Description

Translational pipe CT pick-up unit and detection method thereof

Technical field

The present invention relates to a kind of pipeline inspection pick-up unit, particularly translational pipe CT pick-up unit and detection method thereof.

Background technology

Pipe detection is important maintenance program in industries such as petrochemical industry, chemical industry and electric power, is related to the safe operation of device, is to avoid because weld seam, the burn into substrate of pipeline comes off, crackle and the important means of security incident occurs.

In the prior art, the pipeline of online use generally adopts the method for Non-Destructive Testing, and Non-Destructive Testing does not need the dismounting pipeline, and method is efficient and convenient; But now a large amount of perspective imaging detection methods that adopt can't be avoided the eclipsing effects of object on the directions of rays, can't accomplish real three-dimensional imaging; The lossless detection method that has is installed in x ray generator in the pipeline to be checked, is unsuitable for the detection of closed conduit; The needs that have move pipeline to be checked, and this is unpractical to the pipeline of having fixed; What have needs rotation, and this has increased the difficulty made and to detecting on-the-spot conditional request.

Prior art is used for public places such as aviation, railway, customs the parallel-moving type CT pick-up unit of safety inspections such as container, luggage and articles is comprised the ray generating means, is used to produce ray; Data collector comprises in the face of the detector array of described radiographic source setting and the ray that is used for penetrating by reception the examine object obtains data for projection; Conveyer is used for making examine object between radiographic source and detector array and radiographic source and detector array do linear relative movement in the process of checking; Control and image processing apparatus are used to control described ray generating means, data collector and conveyer, and rebuild the image of examine object from described data for projection.Described control and image processing apparatus comprise: the data for projection conversion portion is used for converting described data for projection to intend under the collimated beam scanning data for projection; The filtering part by with predetermined convolution kernel function and the data for projection convolution of intending under the collimated beam scanning, obtains filtered data for projection; And back projection's part, by being weighted back projection, filtered data for projection comes reconstructed image.Adopt ray generating means and ray detecting apparatus to maintain static in this method, allow object do straight-line scan mode; This is infeasible for the pipeline of having fixed; In addition, because the sweep time of pipeline is longer, if carry out iterative approximation consuming time again after scanning is finished by the time, then the time efficiency of Jian Ceing is not high.Because under the orthoscopic scan mode, the data for projection of examine object is incomplete, this moment is of low quality with the subject image that the reconstruction of convolution backprojection algorithm obtains.

Therefore, need a kind of pipe CT carrying out flaw detection device, can be used for fixing easily pipeline fast, the Non-Destructive Testing of three-dimensional, clear picture.

Summary of the invention

In view of this, the purpose of this invention is to provide a kind of translational pipe CT pick-up unit and detection method thereof, can be used for fixing the detection of pipeline easily, carrying out the multi-process parallel iteration in the time of scanning rebuilds, improve detection efficiency, improve the subject image quality, the apparatus structure compactness, volume is little, low cost of manufacture.

Translational pipe CT pick-up unit of the present invention, comprise ray generating means, data collector and control and image processing system, described ray generating means links to each other with control and image processing system with data collector, also comprise the parallel-moving type mechanical hook-up, described parallel-moving type mechanical hook-up comprises guide rail and slide block, and the relative fixed setting parallel of described guide rail with pipeline to be checked, slide block is arranged on the guide rail in the longitudinally-slidable mode of crosswise fixed, and described ray generating means and data collector are to be arranged on pipeline to be checked both sides with the relatively-stationary mode of slide block.

Further, described parallel-moving type mechanical hook-up also comprises translation driving device, and described translation driving device cooperates with slide block, drives slide block and vertically moves along guide rail;

Further, described guide rail both sides are provided with the longitudinal rail groove respectively, slide block is in the form of slot to be stuck on the guide rail, and two medial surfaces of slide block slot shape are provided with the shape of cross section projection consistent with the guide-track groove shape of cross section, and described projection is embedded in the guide-track groove and can vertically moves along guide-track groove;

Further, described slide block both sides fixedly install crossbeam I and crossbeam II respectively, and described ray generating means and data collector are respectively by crossbeam I and crossbeam II and the setting of slide block relative fixed;

Further, described guide rail be arranged by four legs and the pipeline to be checked that is distributed in pipeline to be checked both sides at least;

Further, the ray that described ray generating means produces is a cone-beam x-ray, and described data collector is a planar array detector;

Further, the cone-beam x-ray that described ray generating means produces is 30 ° to 120 ° with respect to the scope of vertical subtended angle α of data collector, and radially subtended angle β covers pipeline to be checked;

Further, described translation driving device is chain, rack-and-pinion or the screw structure that motor-driven cooperates with slide block.

The invention also discloses a kind of method of translational pipe CT pick-up unit detection pipeline, may further comprise the steps:

A. start ray generating means, data collector, control and image processing system;

B. fractional scanning, slide block moves along guide rail, duct segments is scanned, data collector receives and the passback data for projection, control and image processing system receive data, when the data for projection of a segmentation is complete, the multi-process concurrent reconstruction that carries out this segmentation when continuing scanning, with the ray generating means when each position of this segmentation, the data for projection that data collector obtained is divided into the piece identical with the computing number of processes uniformly along the direction of scanning, and each process is responsible for calculating a piece; With each process i (i=0,1 ..., obtain N dimension image vector F=[f after the volume data discretize of reconstruction regions Ri Q-1) ₁, f ₂, Λ, f _N] ^T, through R _iFlying spot form M dimension data for projection P=[p ₁, p ₂, Λ, p _M] ^T, W=(w _Ij) be M * N dimension projection coefficient matrix, wherein w _IjRepresent the contribution rate of j pixel, R to i bar ray _iImage reconstruction add the type iterative formula below adopting:

$\left\{\begin{array}{c}{f}_j^{\left(0\right)}=0\\ f_j^{\left(k\right)}=f_j^{(k-1)}+\frac{\underset{l\∈[D_i,D_{i+1})}{\mathrm{\Σ}}(\frac{p_l-\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{w}_{\mathrm{lj}}\·f_j^{(k-1)}}{\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{w}_{\mathrm{lj}}}\·w_{\mathrm{lj}})}{\underset{l\∈[D_i,D_{i+1})}{\mathrm{\Σ}}{w}_{\mathrm{lj}}}\end{array}\right.(j=\mathrm{1,2},...,N)$

Wherein, f ⁽⁰⁾Be the initial value of the gradation data of pipeline to be checked, [D _i, D _I+1) be process i (i=0,1 ..., the Q-1) region R of be responsible for rebuilding _iThe scope of corresponding data for projection, k is an iterations;

C. segment reconstruction finishes, and the splicing data show;

D. each process turns to the reconstruction to the next segmentation of pipeline, carries out the online tumbling-type multi-process of segmentation concurrent reconstruction successively, and all pipeline is rebuild when finishing, termination routine.

The invention has the beneficial effects as follows: translational pipe CT pick-up unit of the present invention, employing is simple can be used for fixing the detection of pipeline easily along the parallel mobile pick-up unit of detected pipeline, the apparatus structure compactness, volume is little, low cost of manufacture; Use the parallel iterative reconstruction algorithm that quickens of the online tumbling-type multi-process of segmentation to rebuild tomography or stereo-picture in the time of scanning, improve detection efficiency, improve the subject image quality; The present invention has that inspection speed is fast, image is not overlapping, need not to go deep into pipe interior, do not need advantage such as rotation.

Description of drawings

Below in conjunction with drawings and Examples the present invention is further described.

Fig. 1 is a structural representation of the present invention;

Fig. 2 is vertical subtended angle α synoptic diagram;

Fig. 3 is subtended angle β synoptic diagram radially;

Fig. 4 is duct segments scanning synoptic diagram;

Fig. 5 is a detection method block diagram of the present invention.

Embodiment

Fig. 1 is a structural representation of the present invention, Fig. 2 is vertical subtended angle α synoptic diagram, Fig. 3 is subtended angle β synoptic diagram radially, Fig. 4 is duct segments scanning synoptic diagram, as shown in the figure: translational pipe CT pick-up unit of the present invention, comprise ray generating means 1, data collector 6 and control and image processing system 7, ray generating means 1 links to each other with control and image processing system 7 with data collector 6, the ray that ray generating means 1 produces in the present embodiment is a cone-beam x-ray, data collector 6 is a planar array detector, is applicable to the reception cone-beam x-ray;

Also comprise the parallel-moving type mechanical hook-up, the parallel-moving type mechanical hook-up comprises guide rail 2 and slide block 3 and translation driving device 4, guide rail 2 and pipeline 9 parallel and relative fixed settings to be checked, pipeline 9 to be checked is for being horizontally disposed with in the present embodiment, guide rail 2 is arranged on the top of pipeline 9 to be checked by four legs 8 that are distributed in pipeline to be checked 9 both sides, certain pipeline to be checked 9 also can adopt other set-up mode, guarantees that guide rail is parallel with it, can reach goal of the invention equally; Guide rail 2 both sides are provided with longitudinal rail groove 21 respectively, slide block 3 in the form of slot being stuck on the guide rail 2, two medial surfaces of slide block 3 groove shapes are provided with the shape of cross section projection 31 consistent with guide-track groove 21 shape of cross sections, projection 31 is embedded in the guide-track groove 21 and can vertically moves along guide-track groove 21, slide block 3 is arranged on the guide rail 2 in the longitudinally-slidable mode of crosswise fixed by projection 31 and guide-track groove 21, simple and reliable for structure, processing cost is low; Slide block 3 both sides fixedly install crossbeam I 3a and crossbeam II 3b respectively, ray generating means 1 and data collector 6 are respectively by crossbeam I 3a and crossbeam II 3b and slide block 3 relative fixed settings, ray generating means 1 and data collector 6 are separately positioned on pipeline to be checked 9 both sides, the ray that ray generating means 1 produces with respect to the scope of vertical subtended angle α of data collector 6 can for 30 ° to 120 ° arbitrarily angled, can obtain reconstructed image like this than good quality; Radially subtended angle β covers pipeline to be checked, can certainly be other area-of-interest;

Translation driving device 4 is that motor 5 drives the chain that cooperates with slide block 3, drives slide block 3 and vertically moves along guide rail 2; Can certainly be motor 5 driven wheel tooth bar or screw structures, can reach goal of the invention equally.

Fig. 5 is a detection method block diagram of the present invention, as shown in the figure: utilize translational pipe CT pick-up unit of the present invention to detect the method for pipeline, may further comprise the steps:

A. start ray generating means, data collector, control and image processing system;

B. fractional scanning, slide block moves along guide rail, and with duct segments scanning, Fig. 4 is divided into 9 for duct segments scanning synoptic diagram with pipeline 9 ₁To 9 _LSection scans every section; Data collector receives and the passback data for projection, control and image processing system receive data, when the data for projection of a segmentation is complete, the multi-process concurrent reconstruction that carries out this segmentation when continuing scanning, with the ray generating means when each position of this segmentation, the data for projection that data collector obtained is divided into the piece identical with the computing number of processes uniformly along the direction of scanning, and each process is responsible for calculating a piece; With each process i (i=0,1 ..., reconstruction regions R Q-1) _iThe volume data discretize after obtain N dimension image vector F=[f ₁, f ₂, Λ, f _N] ^T, through R _iFlying spot form M dimension data for projection P=[p ₁, p ₂, Λ, p _M] ^T, W=(w _Ij) be M * N dimension projection coefficient matrix, wherein w _IjRepresent the contribution rate of j pixel, R to i bar ray _iImage reconstruction add the type iterative formula below adopting:

$\left\{\begin{array}{c}{f}_j^{\left(0\right)}=0\\ f_j^{\left(k\right)}=f_j^{(k-1)}+\frac{\underset{l\∈[D_i,D_{i+1})}{\mathrm{\Σ}}(\frac{p_l-\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{w}_{\mathrm{lj}}\·f_j^{(k-1)}}{\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{w}_{\mathrm{lj}}}\·w_{\mathrm{lj}})}{\underset{l\∈[D_i,D_{i+1})}{\mathrm{\Σ}}{w}_{\mathrm{lj}}}\end{array}\right.(j=\mathrm{1,2},...,N)$

Wherein, f ⁽⁰⁾Be the initial value of the gradation data of pipeline to be checked, [D _i, D _I+1) be process i (i=0,1 ..., the Q-1) region R of be responsible for rebuilding _iThe scope of corresponding data for projection, k is an iterations;

C. segment reconstruction finishes, and the splicing data show;

D. each process turns to the reconstruction to the next segmentation of pipeline, carries out the online tumbling-type multi-process of segmentation concurrent reconstruction successively, and all pipeline is rebuild when finishing, termination routine.

Explanation is at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not breaking away from the aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (9)

1. translational pipe CT pick-up unit, comprise ray generating means (1), data collector (6) and control and image processing system (7), described ray generating means (1) links to each other with control and image processing system (7) with data collector (6), it is characterized in that: also comprise the parallel-moving type mechanical hook-up, described parallel-moving type mechanical hook-up comprises guide rail (2) and slide block (3), described guide rail (2) and relative fixed setting parallel with pipeline to be checked (9), slide block (3) is arranged on the guide rail (2) in the longitudinally-slidable mode of crosswise fixed, and described ray generating means (1) and data collector (6) are to be arranged on pipeline to be checked (9) both sides with the relatively-stationary mode of slide block (3).

2. translational pipe CT pick-up unit according to claim 1, it is characterized in that: described parallel-moving type mechanical hook-up also comprises translation driving device (4), described translation driving device (4) cooperates with slide block (3), drives slide block (3) and vertically moves along guide rail (2).

3. translational pipe CT pick-up unit according to claim 2, it is characterized in that: described guide rail (2) both sides are provided with longitudinal rail groove (21) respectively, slide block (3) is in the form of slot to be stuck on the guide rail (2), two medial surfaces of slide block (3) groove shape are provided with the shape of cross section projection (31) consistent with guide-track groove (21) shape of cross section, and described projection (31) is embedded in the guide-track groove (21) and can vertically moves along guide-track groove (21).

4. translational pipe CT pick-up unit according to claim 3, it is characterized in that: described slide block (3) both sides fixedly install crossbeam I (3a) and crossbeam II (3b) respectively, and described ray generating means (1) and data collector (6) are respectively by crossbeam I (3a) and crossbeam II (3b) and slide block (3) relative fixed setting.

5. translational pipe CT pick-up unit according to claim 4 is characterized in that: described guide rail (2) be arranged with to be checked pipeline (9) by four legs (8) that are distributed in pipeline to be checked (9) both sides at least.

6. according to the described translational pipe CT pick-up unit of the arbitrary claim of claim 1 to 5, it is characterized in that: the ray that described ray generating means (1) produces is a cone-beam x-ray, and described data collector (6) is a planar array detector.

7. translational pipe CT pick-up unit according to claim 6, it is characterized in that: the cone-beam x-ray that described ray generating means (1) produces is 30 ° to 120 ° with respect to the scope of vertical subtended angle α of data collector (6), and radially subtended angle β covers pipeline to be checked.

8. translational pipe CT pick-up unit according to claim 2 is characterized in that: described translation driving device (4) drives chain, rack-and-pinion or the screw structure that cooperates with slide block for motor (5).

9. method of utilizing the described translational pipe CT pick-up unit of claim 1 to detect pipeline is characterized in that: may further comprise the steps:

A. start ray generating means, data collector, control and image processing system;

B. fractional scanning, slide block moves along guide rail, duct segments is scanned, data collector receives and the passback data for projection, control and image processing system receive data, when the data for projection of a segmentation is complete, the multi-process concurrent reconstruction that carries out this segmentation when continuing scanning, with the ray generating means when each position of this segmentation, the data for projection that data collector obtained is divided into the piece identical with the computing number of processes uniformly along the direction of scanning, and each process is responsible for calculating a piece; With each process i (i=0,1 ..., reconstruction regions R Q-1) _iThe volume data discretize after obtain N dimension image vector F=[f ₁, f ₂, Λ, f _N] ^T, through R _iFlying spot form M dimension data for projection P=[p ₁, p ₂, Λ, p _M] ^T, W=(w _Ij) be M * N dimension projection coefficient matrix, wherein w _IjRepresent the contribution rate of j pixel, R to i bar ray _iImage reconstruction add the type iterative formula below adopting:

$\left\{\begin{array}{c}{f}_j^{\left(0\right)}=0\\ f_j^{\left(k\right)}=f_j^{(k-1)}+\frac{\underset{l\∈[D_i,D_{i+1}]}{\mathrm{\Σ}}(\frac{p_l-\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{w}_{\mathrm{lj}}\·f_j^{(k-1)}}{\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{w}_{\mathrm{lj}}}\·w_{\mathrm{lj}})}{\underset{l\∈[D_i,D_{i+1}]}{\mathrm{\Σ}}{w}_{\mathrm{lj}}}\end{array}\right.(j=\mathrm{1,2},...,N)$

Wherein, f ⁽⁰⁾Be the initial value of the gradation data of pipeline to be checked, [D _i, D _I+1) be process i (i=0,1 ..., the Q-1) region R of be responsible for rebuilding _iThe scope of corresponding data for projection, k is an iterations;

C. segment reconstruction finishes, and the splicing data show;

D. each process turns to the reconstruction to the next segmentation of pipeline, carries out the online tumbling-type multi-process of segmentation concurrent reconstruction successively, and all pipeline is rebuild when finishing, termination routine.

Images