CN102768020B - Measurement system and method for measuring height of surface of micro object on basis of digital fringe projection technology - Google Patents
Measurement system and method for measuring height of surface of micro object on basis of digital fringe projection technology Download PDFInfo
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- CN102768020B CN102768020B CN201210276379.XA CN201210276379A CN102768020B CN 102768020 B CN102768020 B CN 102768020B CN 201210276379 A CN201210276379 A CN 201210276379A CN 102768020 B CN102768020 B CN 102768020B
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Abstract
The invention discloses a measurement system and a measurement method for measuring the height of the surface of a micro object on the basis of a digital fringe projection technology. The measurement method comprises the following steps of: firstly, constructing a three-dimensional measurement system, wherein the three-dimensional measurement system comprises a working platform, a television microscope lens, a lens assembly and a mini projector, the television microscope lens is vertical to the working platform to be placed downward; a lens of the mini projector is downward and is placed on the same plane with the television microscope lens, the lens assembly is arranged in front of the lens of the mini projector and is used for focusing a sine fringe image projected by the mini projector and the object to be measured is placed on the working platform; and carrying out calibration on the three-dimensional measurement system to obtain a final phase of the surface of the object to be measured so as to obtain the height of the surface of the object to be measured. According to the invention, the height condition of the surface of the object to be measured is accurately obtained; the measurement system and the measurement method have high utilizing value and high accuracy, is convenient to measure and install and has low cost; and a measurement result is specifically shown in Figure 3 and Figure 4.
Description
Technical field
The invention belongs to field of measuring technique, particularly a kind of measuring system and method thereof measuring small items surface elevation based on digital stripe shadow casting technique.
Background technology
Among field of industry detection and industrial design field, microscope is applied widely by people.And by traditional optical microscope, we can only obtain the two-dimensional signal of testee.But, in some specific occasion, when needs do quantitative test time, if only have two-dimensional signal, just obviously can not satisfy the demand.Such as, to the real-time detection of electronic component and detect the surface state of emery wheel.Exactly because these reasons, it is more and more important that the quantitative detection of small items three-dimensional appearance is becoming.
In recent years, a lot of three-dimensional measurement technology all constantly emerged.Three-dimensional measurement technology is generally divided into contact and the large class of noncontact two.The surveying instrument of a kind of precision grown up over nearly 40 years---three coordinate measuring machine is typical instrument with contacts, and it utilizes the surface contact triggering gauge head and measured object to obtain the D coordinates value of contact point.Be widely used in the industry such as machine-building, electronics, automobile and Aero-Space because having the advantages such as precision is high, measurement range is large, performance is good.But three coordinate measuring machine price, high to environmental requirement, measuring speed is slow, and need to carry out Probe-radius Compensation in Reserve to measurement result, these deficiencies limit the application of three coordinate measuring machine.Relative contact type measurement, non-contact measurement have measuring speed fast, measure efficiency high, easily give robotization and the advantage such as flexible, be therefore widely used.Typical non-contact measurement method has optic triangle method, interferometry, structural light measurement method, stereo vision method and imaging radar method etc.Wherein, structural light measurement method, i.e. fringe projection technology, because it has noncontact, harmless, high-level efficiency, high resolving power, the characteristics such as measurement of full field, in industrial detection, product design, engineering in medicine, reverse-engineering, the industries such as anthropological measuring have very large application development potentiality.But, in some researchs in the past, have many people to use grating to produce grating fringe, in order to apply phase-shift method, grating self must move, and not only reduces the speed of measurement like this, and have also been introduced the phase displacement error brought due to mechanical motion, thus reduce measuring accuracy.
In addition, along with the development of digital projection technique, the generation of grating fringe has gradually transferred to and having been completed by digital projector, it is advantageous that and computing machine can be utilized to produce desirable grating fringe fast.But in order to obtain better visual effect, the projection response curve of projector all can be adjusted to non-linear by artificial when designing, and cause the non-sinusoidal of raster image thus, the phase error brought directly affects measuring accuracy simultaneously.
Summary of the invention
The object of the present invention is to provide a kind of measuring system and the method thereof of measuring small items surface elevation based on digital stripe shadow casting technique, solve the technical barrier that traditional optical microscope can only obtain the two-dimensional signal of testee, for small items surface measurement object, television microscope is used to coordinate micro projector to form three-dimension measuring system, obtain the altitudes on object under test surface accurately, and with low cost, structure is simple.
The technical solution realizing the object of the invention is: a kind of measuring method measuring small items surface elevation based on digital stripe shadow casting technique, and step is as follows:
The first step, build three-dimension measuring system, three-dimension measuring system comprises workbench, television microscopy lens head, lens combination and micro projector, television microscopy lens head is put down perpendicular to workbench, the camera lens of micro projector downwards and television microscopy camera lens be placed in same plane, before lens combination is placed on the camera lens of micro projector, be used for focusing on the sine streak image launched of micro projector, object under test is placed with on workbench;
Second step, to three-dimensional measuring systems calibration, the steps include:
1) throw the sine streak in 1 cycle and 2 cycles to workbench with micro projector, utilize the phase place of workbench after three step phase-shift method solution 1 cycle fringe projections, then the phase place now solved, the wrapped phase place of workbench after the 2 cycle fringe projections utilizing this phase place solved to assist solution to be solved by three step phase-shift methods, calls that 2 cycling platforms go the phase place after wrapping up; Then, projected fringe is changed into 4 cycle sinusoidal stripeds, the phase place after wrapping up is gone to assist the wrapped phase place of solution 4 cycling platform with 2 cycling platforms, by that analogy, last solution is to the phase place of going after parcel of 128 cycling platforms, then launch the sine streak only having three gray levels to workbench with micro projector, the solution now wrapped phase place of workbench is carried out with eight step phase-shift methods, and with 128 cycling platforms go wrap up rear phase place to assist solve workbench finally go wrap up after phase place, i.e. fixed phase;
2) ask for the phase value of standard workpiece, workbench is placed the standard workpiece of a known altitude, measure by the method identical with demarcation, the phase place obtained after measurement deducts fixed phase, i.e. the final phase place of standard workpiece;
3) ask for phase place height conversion constant K, according to the final phase place of standard workpiece and the relation of standard workpiece height, obtain constant K, i.e. standard workpiece height
refer to the final phase place of standard workpiece, obtain phase place height conversion constant K;
3rd step, workbench is placed any object under test, measures by the method identical with demarcation, fixed phase is deducted by the phase place obtained after measurement, namely obtain the final phase place on object under test surface, by final phase place multiplication by constants K, the height on object under test surface can be obtained.
The present invention compared with prior art, its remarkable advantage: solve the technical barrier that traditional optical microscope can only obtain the two-dimensional signal of testee, for small items surface measurement object, use television microscope to coordinate micro projector to form three-dimension measuring system, obtain the altitudes on object under test surface accurately, there is very high value, precision is high, and measure, easy for installation, cheap, specifically see the measurement result of Fig. 3 and Fig. 4.
Below in conjunction with accompanying drawing, the present invention is described in further detail.
Accompanying drawing explanation
Fig. 1 the present invention is based on the steps flow chart schematic diagram that the measuring method of small items surface elevation is measured by digital stripe shadow casting technique.
Fig. 2 is for small items digital stripe shadow casting technique three-dimension measuring system structural representation.
Fig. 3 is the surface measuring a piece of paper, and the sine streak cycle is wherein the schematic diagram of 16.
Fig. 4 is the three-dimensional appearance figure on tested paper surface.
Embodiment
Composition graphs 2, the present invention is based on the measuring system that small items surface elevation is measured by digital stripe shadow casting technique, comprise workbench 1, television microscopy lens head 3, lens combination 4 and micro projector 5, television microscopy lens head 3 is put down perpendicular to workbench 1, the camera lens of micro projector 5 can become the angle of 10 °-30 ° to be placed in same plane with television microscopy camera lens 3 downwards, before lens combination 4 is placed on the camera lens of micro projector 5, be used for focusing on the sine streak image launched of micro projector 5, object under test 2 is placed with on workbench 1.It is the biconvex lens of 50.8mm that the lens order of putting from top to bottom of described lens combination 4 is followed successively by a focal length, a focal length is the biconvex lens of 100mm, a focal length is the cemented doublet of 75mm, a polaroid, a focal length is the biconvex lens of 100mm, is upper with the camera lens of micro projector 5.
Composition graphs 1, the present invention is based on the measuring method that small items surface elevation is measured by digital stripe shadow casting technique, step is as follows:
The first step, build three-dimension measuring system, three-dimension measuring system comprises workbench 1, television microscopy lens head 3, lens combination 4 and micro projector 5, television microscopy lens head 3 is put down perpendicular to workbench 1, the camera lens of micro projector 5 is placed in same plane with the angle of 3 one-tenth 10 °-30 °, television microscopy camera lens downwards, before lens combination 4 is placed on the camera lens of micro projector 5, be used for focusing on the sine streak image launched of micro projector 5, object under test 2 is placed with on workbench 1.Micro projector 5 can be DMD projector.
Second step, to three-dimensional measuring systems calibration, the steps include:
1) with the step of micro projector 5 to workbench 1(known altitude) throw the sine streak in 1 cycle and 2 cycles, utilize the phase place of workbench after three step phase-shift method solution 1 cycle fringe projections, then the phase place now solved, the wrapped phase place of workbench after the 2 cycle fringe projections utilizing this phase place solved to assist solution to be solved by three step phase-shift methods, calls that 2 cycling platforms go the phase place after wrapping up; Then, projected fringe is changed into 4 cycle sinusoidal stripeds, the phase place after wrapping up is gone to assist the wrapped phase place of solution 4 cycling platform with 2 cycling platforms, by that analogy, last solution is to the phase place of going after parcel of 128 cycling platforms, then launch the sine streak only having three gray levels to workbench 1 with micro projector 5, the solution now wrapped phase place of workbench is carried out with eight step phase-shift methods, and with 128 cycling platforms go wrap up rear phase place to assist solve workbench finally go wrap up after phase place, i.e. fixed phase; Above-mentioned only have the sine streak of three gray levels to be: often row first pixel gray scale is 255/2, second pixel gray scale is the 255, three pixel gray scale be the 255/2, four pixel gray scale is 0, then carry out repetition 128 times as one-period, complete the value of often row pixel.Described n cycle striped refers to: the sine streak that the sine streak image launched with micro projector was made up of n cycle.
2) ask for the phase value of standard workpiece, workbench 1 is placed the standard workpiece of a known altitude, measure by the method identical with demarcation, the phase place obtained after measurement deducts fixed phase, i.e. the final phase place of standard workpiece.
3) ask for phase place height conversion constant K, according to the final phase place of standard workpiece and the relation of standard workpiece height, obtain constant K, i.e. standard workpiece height
refer to the final phase place of standard workpiece, obtain phase place height conversion constant K.
3rd step, workbench 1 is placed any object under test 2, measures by the method identical with demarcation, fixed phase is deducted by the phase place obtained after measurement, namely obtain the final phase place on object under test 2 surface, by final phase place multiplication by constants K, the height on object under test surface can be obtained.
Three above-mentioned step phase-shift methods are: have the stripe pattern of certain phase shift to calculate by gathering three frames the phase place initial value including testee surface three dimension information; Consider to add several bar graph equations dephased:
I
t(x,y)=I
0(x,y){1＋γ(x,y)cos(φ(x,y)＋α
t]}
Wherein, t represents the moment producing phase shift, I
t(x, y) represents the fringe intensity distribution of t, I
0(x, y) represents background light intensity, and γ (x, y) represents fringe contrast, α
trepresent the known phase shift amount that t is introduced; 3 steps are the minimum step numbers realizing phase-shifting technique; Adopt 3 step phase shifts, control the value α of phase-shift phase
tbe respectively
i can be obtained
1i
2i
3three spoke print images; Then form system of equations by this three width bar graph, the phase place exact solution that can solve in formula is:
Eight described step phase-shift methods are: similar to above-mentioned three step phase-shift methods, adopt 8 step phase shifts, control the value α of phase-shift phase
tbe respectively
i can be obtained
1i
2i
3i
4i
5i
6i
7i
8eight spoke print images; Then form system of equations by this eight width bar graph, the phase place exact solution that can solve in formula is:
The method of described auxiliary solution phase place is:
Φ
2k(x,y)＝φ
2k(x,y)＋2m(x,y)π
Wherein, Φ
2kwhen (x, y) is for 2k cycle fringe projection, the wrapped phase place of point (x, y); φ
2kwhen (x, y) is for 2k cycle fringe projection, point (x, y) goes the phase place after wrapping up.
Claims (2)
1. measure a measuring method for small items surface elevation based on digital stripe shadow casting technique, it is characterized in that step is as follows:
The first step, build three-dimension measuring system, three-dimension measuring system comprises workbench (1), television microscopy lens head (3), lens combination (4) and micro projector (5), television microscopy lens head (3) is put down perpendicular to workbench (1), the camera lens of micro projector (5) becomes the angle of 10 °-30 ° to be placed in same plane with television microscopy lens head (3) downwards, before lens combination (4) is placed on the camera lens of micro projector (5), be used for focusing on micro projector (5) the sine streak image launched, object under test (2) is placed with on workbench (1),
Second step, to three-dimensional measuring systems calibration, the steps include:
1) throw the sine streak in 1 cycle and 2 cycles to workbench (1) with micro projector (5), utilize the phase place of workbench after three step phase-shift method solution 1 cycle fringe projections, then the phase place now solved, the wrapped phase place of workbench after the 2 cycle fringe projections utilizing this phase place solved to assist solution to be solved by three step phase-shift methods, calls that 2 cycling platforms go the phase place after wrapping up; Then, projected fringe is changed into 4 cycle sinusoidal stripeds, the phase place after wrapping up is gone to assist the wrapped phase place of solution 4 cycling platform with 2 cycling platforms, by that analogy, last solution is to the phase place of going after parcel of 128 cycling platforms, then micro projector (5) is used to launch to workbench (1) sine streak only having three gray levels, the solution now wrapped phase place of workbench is carried out with eight step phase-shift methods, and with 128 cycling platforms go wrap up rear phase place to assist solve workbench finally go wrap up after phase place, i.e. fixed phase;
2) ask for the phase value of standard workpiece, at the standard workpiece of the upper placement known altitude of workbench (1), measure by the method identical with demarcation, the phase place obtained after measurement deducts fixed phase, i.e. the final phase place of standard workpiece;
3) ask for phase place height conversion constant K, according to the final phase place of standard workpiece and the relation of standard workpiece height, obtain constant K, i.e. standard workpiece height
obtain phase place height conversion constant K,
refer to the final phase place of standard workpiece;
3rd step, at workbench (1) any object under test of upper placement (2), measure by the method identical with demarcation, fixed phase is deducted by the phase place obtained after measurement, namely the final phase place on object under test (2) surface is obtained, by final phase place multiplication by constants K, the height on object under test surface can be obtained.
2. the measuring method measuring small items surface elevation based on digital stripe shadow casting technique according to claim 1, it is characterized in that the described sine streak of three gray levels that only has is: often row first pixel gray scale is 255/2, second pixel gray scale is 255,3rd pixel gray scale is 255/2,4th pixel gray scale is 0, then carry out repetition 128 times as one-period, complete the value of often row pixel.
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| CN103383360B (en) * | 2013-07-29 | 2016-01-13 | 重庆理工大学 | A kind of thin strap continuous casting blank surface defects sinusoidal grating phase shift detection device and detection method |
| CN103727875A (en) * | 2013-12-09 | 2014-04-16 | 乐视致新电子科技（天津）有限公司 | Measurement method based on smart television and smart television |
| CN105841620B (en) * | 2016-03-22 | 2019-01-25 | 上海交通大学 | Off-surface displacement measurement system and method based on projection moire method |
| CN107610183B (en) * | 2017-09-25 | 2020-12-15 | 天津大学 | Calibration method of fringe projection phase height conversion mapping model |
| CN108180868A (en) * | 2017-12-29 | 2018-06-19 | 南京理工大学 | A kind of real-time three-dimensional micro imaging system based on fringe projection |
| CN110398201B (en) * | 2019-08-06 | 2021-08-06 | 湖南大学 | Displacement measuring method combining digital image correlation technique and Moire sampling method |
| CN110864650A (en) * | 2019-11-25 | 2020-03-06 | 天津大学 | Flatness measuring method based on fringe projection |
| CN111174704B (en) * | 2019-11-26 | 2022-04-19 | 武汉华工激光工程有限责任公司 | Method for measuring height of tin ball by gray image |
| CN113237436B (en) * | 2021-04-07 | 2022-08-02 | 上海大学 | Device and method for measuring shape of polarized light space phase shift non-Lambertian metal object |
| CN115014242B (en) * | 2022-05-26 | 2023-03-10 | 华中科技大学 | Microcosmic surface topography measuring method and device based on parallel multi-slit structure illumination |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2784875Y (en) * | 2005-03-22 | 2006-05-31 | 范光照 | Novel micro three-dimensional topography measurer based on fiber-optic image bundles |
| CN201081696Y (en) * | 2007-06-13 | 2008-07-02 | 沈阳同联集团高新技术有限公司 | Micro three-dimensional projection pattern measuring device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011112639A (en) * | 2009-11-27 | 2011-06-09 | Nippon Kensaki Kk | Three-dimensional shape measuring system |
| JP5743419B2 (en) * | 2010-04-18 | 2015-07-01 | 国立大学法人宇都宮大学 | Shape measuring method and apparatus and strain measuring method and apparatus |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2784875Y (en) * | 2005-03-22 | 2006-05-31 | 范光照 | Novel micro three-dimensional topography measurer based on fiber-optic image bundles |
| CN201081696Y (en) * | 2007-06-13 | 2008-07-02 | 沈阳同联集团高新技术有限公司 | Micro three-dimensional projection pattern measuring device |
Non-Patent Citations (1)
| Title |
|---|
| 基于正弦条纹投影的三维传感及其去包裹处理;康新等;《光学学报》;20011231;第21卷(第12期);第1444-1447页 * |
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