CN101231161B - Method for measuring particle diameter - Google Patents
Method for measuring particle diameter Download PDFInfo
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- CN101231161B CN101231161B CN200710036728XA CN200710036728A CN101231161B CN 101231161 B CN101231161 B CN 101231161B CN 200710036728X A CN200710036728X A CN 200710036728XA CN 200710036728 A CN200710036728 A CN 200710036728A CN 101231161 B CN101231161 B CN 101231161B
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Abstract
The invention relates to a method of measuring a particle diameter by utilizing gray level difference of particle images, and belongs to the technical field of optical measurement of the particle diameter. The method utilizes an imaging system of a particle image speed field apparatus to obtain the particle images with gray level difference, wherein, the particle images are formed in the way that a flow field is exposed twice, and the imaging system of the particle image speed field apparatus is used for distinguishing and enquiring gray level statistics. The particle images are pretreated by using an image treatment technology, and a method of using particle image gray level autocorrelation to measure the particle velocity is used to realize that one same particle is performed exposure twice to be conjugated with image points of corresponding two particles. The size of the particle diameter can be obtained by the total gray level of the image points of the two particles via a solution formula of the particle diameter, so the particle diameter information of entire flow field is obtained. By using the invention, the demand of the stability of laser intensity is lowered, and the systematic errors and the affection of digital image treatment technology and laser diffraction on measuring results of the particle diameter are reduced. Besides, the invention overcomes the shortcoming and the defection in the prior art and has substantial characteristics and obvious improvement.
Description
Technical field
The invention belongs to the particle diameter field of optical measuring technologies, what relate to is the method for measuring the flow field particle diameter, and particularly a kind of use particle picture velocity field instrument (PIV) is taken the flow field particle picture and utilized the particle picture gray difference to measure the method for particle diameter.
Background technology
The experiment measuring of particle diameter and velocity distribution is the main contents of flow field demonstration and Quantitative Study thereof.Particle picture velocity field instrument PIV (Particle Image Velocimetry) melts Computer Image Processing and optical technology is an one, instantaneous velocity and stream field with energy measurement research space whole flow field disturb little advantage, become a very effective instrument of flow-field test and analysis.But the PIV technology can't be used for measuring when particle diameter is measured with realization flow field particle diameter and velocity distribution.For further expanding the usable range of PIV system, satisfy testing requirement, in recent years, people have done a large amount of research to how utilizing the PIV system to carry out flow field particle diameter measurement.
The simplest method of utilizing the PIV system to realize that particle diameter is measured is exactly to handle the single width particle picture of the single exposure that is obtained by the PIV system, obtain the number of pixels that each particle picture point comprises on the image, area as the particle picture point, with the equivalence of particle picture point is the round particle picture point, obtains the particle diameter information of particle on the image by area of a circle computing formula.Other method is to install a slit plate before the CCD camera lens additional, utilizes non-focal plane imaging to obtain the interference fringe of particle, measures fringe spacing to obtain the particle diameter distributed intelligence of whole flow field.
In the prior art, Wang Xishi, Liao Guangxuan etc. are at " A method of extending DPIV and its applicationin spray droplet size measurements " (" Chinese Science Bulletin ", the method of the digital PIV systematic survey spray particle diameter of Vol.47NO.12 June2002) introducing in the literary composition, be to utilize the PIV system to obtain the particle picture of spraying, proofread and correct by adopting image collection on computers, level and smooth and denoising, binaryzation, element is cut apart and digital image analysis disposal routes such as expansion and corrosion are carried out pre-service to particle picture, again pretreated particle picture is made particle identification and statistics, obtain the number of pixels that each particle picture point occupies, the particle diameter that obtains whole spraying by area of a circle computing formula distributes.The shortcoming of this method is that various digital image analysis preprocess methods all can influence the size of particle picture point, thereby has influence on determining of particle diameter full-size(d); Simultaneously, this method is very high to the stability requirement of laser intensity, and in a single day laser intensity changes, and just need reset various digital image analysis disposal routes; In addition, the also influence of Stimulated Light diffraction and PIV systematic error of particle imaging.
Summary of the invention
The purpose of this method is to provide a kind of method of utilizing the particle picture gray difference to measure particle diameter, the particle picture velocity field instrument imaging system that this method utilization is used for the gray-scale statistics classification inquiry obtains the particle picture with gray difference that the flow field forms through double exposure, after Flame Image Process, obtain the particle diameter information in whole flow field by specific particle diameter solution formula.
The particle picture velocity field instrument imaging system that utilization is used for the gray-scale statistics classification inquiry obtains the particle picture with gray difference that the flow field forms through double exposure, after the image processing techniques pre-service, realize the double expose pairing of corresponding two particle picture point of same particle, gray scale summation by the two particle picture point obtains the particle diameter size through the particle diameter solution formula, thereby obtains the particle diameter information in whole flow field.
Further, the present invention can be achieved through the following technical solutions, and specifically comprises:
(1) choose reasonable is set each parameter of the particle picture velocity field instrument imaging system be used for the gray-scale statistics classification inquiry: set the side length b of the square aperture of the orifice plate that installs additional before the wavelength X of semiconductor pumped continuous wave laser emitted laser, the used camera lens ', camera lens is to the vertical range d of laser optical path
1, laser optical path and camera lens axis angle θ
0, the laser sheet optical pulse width is camera double exposure time t
1And t
2The laser output power P of duration T that camera shutter is opened and decision laser sheet optical pulse light intensity I; And with each parameter input computing machine.
(2) be used for the particle picture with gray difference of flow field to be measured of particle picture velocity field instrument imaging system acquisition of gray-scale statistics classification inquiry through double exposure: the particle picture velocity field instrument imaging system that is used for the gray-scale statistics classification inquiry is successively launched the laser sheet optical pulsing light flow field to be measured that two bundles have identical light intensity distinct pulse widths, camera follows laser pulse to double expose, obtain the double-exposure particle picture that a width of cloth has gray difference, the input computing machine.
(3) use a computer particle picture is done pre-service: adopt suitable digital image processing techniques such as level and smooth and denoising that particle picture is done pre-service at the various flows field characteristic, remove background and other noise effect in the image, improve picture quality.
(4) obtain the position and the gray scale summation information of each particle picture point on the particle picture of flow field: particle picture is made rim detection, distinguish each the different particle picture points on the image, obtain positional information x and the y and the area size S of particle picture point simultaneously; Obtain the gray scale summation information G of each particle picture point correspondence again in conjunction with particle picture after the pre-service.
(5) particle of the different gray scales of pairing single particle double exposure correspondence is right: the inquiry zonule that particle picture is divided into a certain size, with identical size, the particle picture point of same grayscale is replaced original each particle picture point in the zonule, fast two-dimensional fourier transformation is made in zonule after replacing, auto-correlation peak value zoning relative displacement by the conversion acquisition, realize the pairing of corresponding different gray scale particle picture points that double exposes of same particle in conjunction with the ratio of each particle double exposure particle picture point gray scale summation in the zonule and the conditions such as inner link of laser sheet optical pulse width ratio, and extend to whole particle picture.
(6) according to the different half-tone informations of the paired two particle picture point of each particle and the parameter of the imaging system of select setting before, obtain the particle diameter information in whole flow field: each parameter of the particle picture velocity field instrument imaging system by aforementioned acquisition, utilize formula (a), try to achieve particle diameter and find the solution coefficient k, can obtain the particle diameter information of each particle according to the different half-tone information utilizations of the paired two particle picture point of each particle on the particle picture based on the granularity solution formula (b) of gray difference differentiation.
Wherein: K is coefficient, the K of gradation of image for the camera exposure Conversion of energy
MFor power equivalent, a are particle diameter; G
1Gray scale summation for the particle that exposes for the first time; G
2Gray scale summation for the particle that exposes for the second time.
Further, also can comprise: (7) output particle diameter frame: the particle diameter information that will obtain whole flow field is presented on the computer screen with the form of image, or by printer output.
Beneficial effect of the present invention: the present invention utilizes twice different-energy laser pulse of priority to obtain to have the particle picture of gray difference, in the solution procedure with laser intensity as input parameter, the fluctuation of light intensity can directly embody in the particle diameter solution procedure, the laser intensity restriction of having avoided particle diameter to measure; Utilize image particle gray-scale value under the pulsing light of identical light intensity distinct pulse widths laser sheet optical to subtract each other and ask for particle diameter, farthest eliminated the influence of systematic error and laser diffraction; The half-tone information of the particle picture point of same particle double exposure is all handled through the same numbers image processing method and is obtained, and the various Flame Image Process errors of bringing are thus eliminated under gray-scale value subtracts each other substantially.Overcome deficiency of the prior art and defective, had substantive distinguishing features and marked improvement.
Embodiment
Below in conjunction with the particle diameter information embodiment that measures the trace particle that adds in the tank flow field the present invention is described in further detail:
(1) because the flow velocity in tank flow field is slow, particle is greatly and more sparse in the flow field, Measurement Resolution is less demanding, thereby it is as follows to set each parameter of the particle picture velocity field instrument imaging system be used for the gray-scale statistics classification inquiry: the wavelength of semiconductor pumped continuous wave laser emitted laser is that the length of side of the square aperture of the orifice plate that installs additional before λ=532nm, the used camera lens is that b '=14mm, camera lens to the vertical range of laser optical path are d
1=500mm, laser optical path and camera lens axis angle are θ
0=90 °, laser sheet optical pulse width are camera double exposure time t
1=5ms and t
2=10ms, camera shutter are opened the laser output power P=100mw of duration T=130ms and decision laser sheet optical pulse light intensity I; Parameter values is imported computing machine.
(2) the laser sheet optical pulse is successively shone the tank flow field twice, and camera is followed laser pulse to double expose and obtained the particle picture with gray difference in flow field, transfer to computing machine.
(3) the gained particle picture is adopted digital image processing techniques such as level and smooth and denoising, remove background and other noise effect in the image, improve picture quality, the real information of reduction particle picture point.
(4) adopt improved differentiating operator further particle picture to be made rim detection according to the experiment concrete condition, distinguish each particle picture point and obtain the positional information x of particle picture point and y and area size S; Obtain the gray scale summation information G of each particle picture point correspondence in conjunction with pretreated particle picture.
(5) according to requirement of experiment such as flow field situation and resolution particle picture is divided 64 pixels * 64 pixel zonules, in the zonule, be 3 pixels * 3 pixels with size, each pixel grey scale is that 255 particle picture point is replaced all original particle picture points, fast two-dimensional fourier transformation is carried out in zonule after replacing, obtain the auto-correlation peak value with the zoning relative displacement, realize the pairing of corresponding different gray scale particle picture points that double exposes of same particle in conjunction with conditions such as the ratio of each particle double exposure particle picture point gray scale summation in the zonule and laser sheet optical pulse width ratio are linearly proportional within the specific limits, and expand extremely whole particle picture.
(6) by each parameter of the particle picture velocity field instrument imaging system that obtains in 1., utilize formula
Try to achieve particle diameter and find the solution the coefficient k value, then according to the different gray value informations of the pairing particle picture point of each particle through the particle diameter solution formula
Obtain the particle diameter information of each particle after the calculating.(wherein: K is coefficient, the K of gradation of image for the camera exposure Conversion of energy
MFor power equivalent, a are particle diameter; G
1Gray scale summation for the particle that exposes for the first time; G
2Gray scale summation for the particle that exposes for the second time.)
(7) the particle diameter distributed intelligence in the whole flow field that on computer screen, show to obtain or by printer output.
The above-mentioned description to embodiment is can understand and apply the invention for ease of those skilled in the art.The person skilled in the art obviously can easily make various modifications to these embodiment, and needn't pass through performing creative labour being applied in the General Principle of this explanation among other embodiment.Therefore, the invention is not restricted to the embodiment here, those skilled in the art should be within protection scope of the present invention for improvement and modification that the present invention makes according to announcement of the present invention.
Claims (4)
1. method of measuring particle diameter, it is characterized in that: the particle picture velocity field instrument imaging system that is used for the gray-scale statistics classification inquiry is taken the flow field particle picture, and utilize the particle picture gray difference to measure particle diameter, the particle picture velocity field instrument imaging system that its utilization is used for the gray-scale statistics classification inquiry obtains the particle picture with gray difference that the flow field forms through double exposure, after the image processing techniques pre-service, realize the double expose pairing of corresponding two particle picture point of same particle, gray scale summation by the two particle picture point obtains the particle diameter size through the particle diameter solution formula, thereby obtain the particle diameter information in whole flow field, concrete steps are as follows:
(1) set the side length b of the square aperture of the orifice plate that installs additional before the wavelength X of semiconductor pumped continuous wave laser emitted laser, the used camera lens ', camera lens is to the vertical range d of laser optical path
1, laser optical path and camera lens axis angle θ
0, the laser sheet optical pulse width is camera double exposure time t
1And t
2The laser output power P of duration T that camera shutter is opened and decision laser sheet optical pulse light intensity I; And with each parameter input computing machine;
(2) the particle picture velocity field instrument imaging system that is used for the gray-scale statistics classification inquiry is successively launched the laser sheet optical pulsing light flow field to be measured that two bundles have identical light intensity distinct pulse widths, camera follows laser pulse to double expose, obtain the double-exposure particle picture that a width of cloth has gray difference, the input computing machine;
(3) adopt suitable level and smooth and denoising digital image processing techniques that particle picture is done pre-service at the various flows field characteristic, remove background and other noise effect in the image, improve picture quality;
(4) particle picture is made rim detection, distinguish each the different particle picture points on the image, obtain positional information x and the y and the area size S of particle picture point simultaneously; Obtain the gray scale summation information G of each particle picture point correspondence again in conjunction with particle picture after the pre-service;
(5) particle picture is divided into a certain size inquiry zonule, particle picture point with identical size, same grayscale is replaced original each particle picture point in the zonule, fast two-dimensional fourier transformation is made in zonule after replacing, the auto-correlation peak value zoning relative displacement that is obtained by conversion realizes the double expose pairing of corresponding different gray scale particle picture points of same particle in conjunction with the ratio of each particle double exposure particle picture point gray scale summation in the zonule and the inner link condition of laser sheet optical pulse width ratio;
(6) each parameter of the particle picture velocity field instrument imaging system by aforementioned acquisition, utilize formula (a), try to achieve particle diameter and find the solution coefficient k, can obtain the particle diameter information of each particle according to the different half-tone information utilizations of the two particle picture point of each particle pairing on the particle picture based on the granularity solution formula (b) of gray difference differentiation;
Wherein, K is coefficient, the K of gradation of image for the camera exposure Conversion of energy
MFor power equivalent, a are particle diameter; G
1Gray scale summation for the particle that exposes for the first time; G
2Gray scale summation for the particle that exposes for the second time.
2. the method for measurement particle diameter according to claim 1 is characterized in that: also comprise: the particle diameter information that will obtain whole flow field is presented on the computer screen with the form of image, or by printer output.
3. the method for measurement particle diameter according to claim 1 is characterized in that: the wavelength of the semiconductor pumped continuous wave laser emitted laser described in the step (1) is that the length of side of the square aperture of the orifice plate that installs additional before λ=532nm, the used camera lens is that b '=14mm, camera lens to the vertical range of laser optical path are d
1=500mm, laser optical path and camera lens axis angle are θ
0=90 °, laser sheet optical pulse width are camera double exposure time t
1=5ms and t
2=10ms, camera shutter are opened the laser output power P=100mw of duration T=130ms and decision laser sheet optical pulse light intensity I.
4. the method for measurement particle diameter according to claim 1 is characterized in that: the zonule size that the particle picture described in the step (5) is divided is 64 pixels * 64 pixels.
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| CN102353337B (en) * | 2011-09-19 | 2013-05-08 | 南京信息工程大学 | Method and device for detecting diameter of atmospheric black carbon aerosol particle |
| CN102436015B (en) * | 2011-12-02 | 2014-01-08 | 南京英恩特环境技术有限公司 | Method and rain gauge for measuring rainfall by pulse illumination optics |
| CN103256899B (en) * | 2013-04-15 | 2016-08-10 | 同济大学 | A kind of measuring method of mean particle dia |
| CN110793450B (en) * | 2019-10-15 | 2022-05-31 | 哈尔滨工程大学 | High-precision particle size measuring device and method based on optical fiber tweezers |
| CN113552028B (en) * | 2020-04-23 | 2022-12-13 | 中冶长天国际工程有限责任公司 | Mixture visual analysis device, and method and system for detecting granularity composition of mixture |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19928698A1 (en) * | 1999-06-23 | 2000-09-21 | Deutsch Zentr Luft & Raumfahrt | Particle image velocimetry (PIV) measurement device, has light source illuminating slit and camera for taking successive images of particles in motion |
| US6879708B2 (en) * | 2001-05-24 | 2005-04-12 | Case Western Reserve University | Planar particle/droplet size measurement technique using digital particle image velocimetry image data |
| CN1763546A (en) * | 2005-11-03 | 2006-04-26 | 上海交通大学 | Imaging system of particle image velocimetry for gray scale statistics, discrimination and query |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19928698A1 (en) * | 1999-06-23 | 2000-09-21 | Deutsch Zentr Luft & Raumfahrt | Particle image velocimetry (PIV) measurement device, has light source illuminating slit and camera for taking successive images of particles in motion |
| US6879708B2 (en) * | 2001-05-24 | 2005-04-12 | Case Western Reserve University | Planar particle/droplet size measurement technique using digital particle image velocimetry image data |
| CN1763546A (en) * | 2005-11-03 | 2006-04-26 | 上海交通大学 | Imaging system of particle image velocimetry for gray scale statistics, discrimination and query |
Non-Patent Citations (7)
| Title |
|---|
| J.R.Kadambi ,et al.Particle sizing using Particle Imaging Velocimetry for two-phase flows.PowderTechnology100.1998,100251-259. |
| J.R.Kadambi,et al.Particle sizing using Particle Imaging Velocimetry for two-phase flows.PowderTechnology100.1998,100251-259. * |
| JP特开2006-313307A 2006.11.16 |
| 张伟等.基于灰度统计的粒子图像速度粒度实时测量新技术.应用激光25 2.2005,25(2),121-124. |
| 张伟等.基于灰度统计的粒子图像速度粒度实时测量新技术.应用激光25 2.2005,25(2),121-124. * |
| 朱立褀等.一种激光粒子图像速度粒度实时同场测量技术查询系统的开发.应用激光26 6.2006,26(6),第422页左栏最后一段至第424页左栏第1段、图1. |
| 朱立褀等.一种激光粒子图像速度粒度实时同场测量技术查询系统的开发.应用激光26 6.2006,26(6),第422页左栏最后一段至第424页左栏第1段、图1. * |
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