CN111829446A - High-precision double-axis optical extensometer using plurality of rhombic prisms - Google Patents
High-precision double-axis optical extensometer using plurality of rhombic prisms Download PDFInfo
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- CN111829446A CN111829446A CN202010659710.0A CN202010659710A CN111829446A CN 111829446 A CN111829446 A CN 111829446A CN 202010659710 A CN202010659710 A CN 202010659710A CN 111829446 A CN111829446 A CN 111829446A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
Abstract
The invention discloses a high-precision biaxial optical extensometer using a plurality of rhombic prisms, which comprises: the digital camera, a telecentric lens, four rhombic prisms, a fixed flat plate, a tripod and a data processing device; the four rhombic prisms are fixed in the fixed flat plate and are respectively positioned in four directions of upper, lower, left and right, and are arranged at equal intervals from the central point of the fixed flat plate; after the target points on the surface of the tested sample are reflected for two times in sequence, the target points are converged and incident into the telecentric lens; the telecentric lens simultaneously images to form a digital image; the digital camera simultaneously shoots four target areas to obtain digital images; the data processing device comprises a correlation operation module and a post-processing module, displacement information of the four target points along the measuring direction is obtained according to the received digital image, and local uniform strain information is obtained by combining the distance information of the four target points. The invention simplifies the implementation steps of bidirectional view field separation, and the scale distance is amplified by multiple times, thereby greatly improving the measurement precision of biaxial strain.
Description
Technical Field
The invention relates to a high-precision biaxial optical extensometer utilizing a plurality of rhombic prisms, belonging to the technical field of optical measurement and nondestructive testing.
Background
In order to obtain the two constants of the elastic modulus and the poisson ratio of the material, the transverse and axial strain of the material, namely the bidirectional strain, must be accurately measured in the elastic range. The most common test means at present are sticking right-angle strain patterns and adopting a biaxial electronic extensometer to obtain bidirectional strain, and the methods need to be in direct contact with a tested sample during measurement, so that the sample is easy to damage, and therefore, the methods are not suitable for detecting large deformation, particularly flexible materials, and the optical non-contact measurement method is greatly obvious. The optical strain test method is mainly represented by an optical (video) extensometer, but is affected by the out-of-plane displacement of a sample during testing and limited by the resolution of a camera, and the strain measurement precision of the current optical extensometer is often not high and cannot meet the deformation measurement of brittle materials such as concrete, ceramic and the like.
Aiming at the problem, Pan and the like propose that the influence of out-of-plane displacement is reduced by using a bilateral telecentric lens, but the strain measurement precision is still limited by the resolution of a camera; the method for realizing the separation of the view fields by using the four-plane mirror is provided by julient et al, the extensometer gauge length is improved, and the method is combined with a telecentric lens to reduce the influence of out-of-plane displacement, however, the method can only improve the strain precision in a single direction, and can not obtain high-precision bidirectional strain measurement results at the same time.
Disclosure of Invention
In order to solve the problem of the existing optical extensometer in the aspect of bidirectional strain measurement precision, the invention aims to provide a high-precision biaxial optical extensometer utilizing a plurality of rhombic prisms, a technology of realizing bidirectional view field separation by utilizing four rhombic prisms, and a high-precision bidirectional optical extensometer formed by combining with a telecentric lens. The optical extensometer is used for strain test, the scale distance of the extensometer can be increased by several times, and false displacement and false strain caused by the out-of-plane displacement of a tested sample can be effectively eliminated, so that high-precision bidirectional strain measurement is realized.
The invention specifically adopts the following technical scheme to solve the technical problems:
a high precision biaxial optical extensometer utilizing a plurality of rhomboid prisms comprising: the digital camera comprises a digital camera, a telecentric lens, four rhombic prisms, a fixed flat plate, a tripod for bearing the digital camera and a data processing device; the four rhombic prisms are fixed in the fixed flat plate and are respectively positioned at four directions of the upper part, the lower part, the left side, the right side, the left side and the right side of the fixed flat plate, the left rhombic prism and the right rhombic prism are respectively positioned at the lower side and the upper side of the horizontal straight line, the upper rhombic prism and the lower rhombic prism are respectively positioned at the left side and the right side of the vertical straight line, and the four rhombic prisms are arranged at equal intervals from the central point of the fixed flat;
after four target points on the surface of the tested sample are reflected twice in an oblique square prism in sequence, convergence occurs and the four target points enter the telecentric lens in a direction parallel to the optical axis of the telecentric lens; the telecentric lens simultaneously images upper, lower, left and right target areas on the surface of the sample to be measured after secondary reflection, and forms a digital image on the target surface of the digital camera; the digital camera simultaneously shoots four target areas to obtain a digital image, the shot digital image is transmitted to the data processing module, and the information of each target area occupies one fourth of the target surface of the digital camera, so that the simultaneous acquisition of four separated target images is realized; the data processing device comprises a correlation operation module and a post-processing module, wherein the correlation operation module acquires displacement information of four target points along a measuring direction according to a received digital image, and the post-processing module acquires local uniform strain information of the surface of the sample to be measured by using the displacement information acquired by the correlation operation module and combining the distance information of the four target points.
Further, as a preferred technical solution of the present invention: the telecentric lens is an object-side telecentric lens or a bilateral telecentric lens.
Further, as a preferred technical solution of the present invention: the post-processing module obtains the horizontal uniform strain of the surface of the tested sample as (x)2-x1)/sH，x1And x2Displacement of the first and second target points, s, respectively, in the horizontal directionHThe initial distance between the left target point and the right target point is set; and obtaining the vertical uniform strain magnitude (y) of the surface of the tested sample2-y1)/sV，y1And y2Displacement of the third and fourth target points, respectively, in the vertical direction, sVThe initial distance between the upper and lower target points.
By adopting the technical scheme, the invention can produce the following technical effects:
(1) low cost, easy equipment, the integrated level is high: only four rhombic prisms with the same size are needed, and the prism processing cost is very low; the existing four-reflector device needs to finely adjust the deflection angle of each reflector one by one when realizing the one-way field separation, and the whole process is relatively troublesome, but the invention adopts the optical arrangement of four rhombic prisms to simplify the realization steps of the two-way field separation, and the four-reflector device is easy to assemble and integrate into a single device and is directly connected with a lens, so that the complicated adjustment steps are avoided;
(2) the double-shaft strain measurement precision is high: the strain measurement precision of the optical extensometer is limited by the resolution of a camera, and the arrangement of four rhombic prisms can converge four target points with longer distances, namely left, right, upper and lower target points, into a telecentric lens through light path reflection, so that the distance between the target points in the horizontal direction and the vertical direction, namely the gauge length, is multiplied by several times, and the measurement precision of biaxial strain is greatly improved;
(3) little influence by the sample out-of-plane displacement: because the telecentric lens has the characteristic of constant magnification in the field depth range, the micro out-of-plane displacement of the target point does not generate false displacement and false strain on the image surface of the digital camera, thereby obtaining higher displacement measurement precision.
Drawings
Fig. 1 is a schematic view of the measurement principle of the optical extensometer according to the present invention.
Fig. 2(a), (b), and (c) are a front view, a side view, and a plan view, respectively, of the arrangement of four rhombic prisms according to the present invention.
FIG. 3 is a schematic diagram of a single rhombus prism used in the present invention.
FIG. 4 is a schematic diagram illustrating the principle of eliminating out-of-plane displacement according to the present invention.
Wherein the reference numerals explain: 1-a sample to be measured, 2-four target points, 3-a digital camera, 4-a telecentric lens, 5-a tripod, 6-a first rhombic prism, 7-a second rhombic prism, 8-a third rhombic prism, 9-a fourth rhombic prism and 10-a fixed plate.
Detailed Description
The following describes embodiments of the present invention with reference to the drawings.
As shown in fig. 1, an embodiment of the present invention discloses a high-precision biaxial optical extensometer using a plurality of rhombic prisms,
the high-precision double-shaft optical extensometer for realizing bidirectional visual field separation based on four rhombic prisms comprises a digital camera 3, a telecentric lens 4, four rhombic prisms, namely a left rhombic prism 6, a right rhombic prism 7, an upper rhombic prism 8, a lower rhombic prism 9, a fixed flat plate 10 for fixedly placing the rhombic prisms, a tripod 5 for bearing the digital camera and a data processing device;
firstly, selecting four target points 2 of an optical extensometer on a sample 1 to be measured, wherein a left target point and a right target point form a horizontal extensometer, an upper target point and a lower target point form a vertical extensometer, and installing four rhombic prisms 6, 7, 8 and 9 with the same size in a fixed flat plate 10 as shown in figure 1, wherein the inclined plane of each prism forms 45 degrees with the surface of the sample 1 to be measured. The four rhombic prisms are arranged as shown in fig. 1, fixed in a fixed plate 10 and respectively located at four positions of the fixed plate, namely, the upper, lower, left and right directions, wherein the left and right rhombic prisms 6 and 7 are respectively located at the lower and upper sides of a horizontal straight line, the upper and lower rhombic prisms 8 and 9 are respectively located at the left and right sides of a vertical straight line, the four rhombic prisms are all arranged at equal intervals from the central point of the fixed plate 10, and the front view, the side view and the top view of the rhombic prisms are shown in fig. 2(a), (b) and (c). The incident surfaces of the four rhombic prisms face the surface to be measured of the sample to be measured, the centers of the four rhombic prisms are positioned on the same circumference, and the emergent surfaces of the four rhombic prisms 6, 7, 8 and 9 face the telecentric lens direction and are closely arranged and respectively correspond to four areas, namely the left lower area, the right upper area, the left upper area and the right lower area, of the telecentric lens.
The light rays emitted from the four target points on the surface of the measured sample will vary as follows: the two inclined planes of the left inclined prism 6 translate the light rays emitted by the first (left) target point to the right by a horizontal distance and then enter the telecentric lens 4, the two inclined planes of the right inclined prism 7 translate the light rays emitted by the second (right) target point to the left by a same horizontal distance and then enter the telecentric lens 4, the two inclined planes of the upper inclined prism 8 translate the light rays emitted by the third (upper) target point to the lower by a vertical distance and then enter the telecentric lens 4, and the two inclined planes of the lower inclined prism 9 translate the light rays emitted by the fourth (lower) target point to the upper by a vertical distance and then enter the telecentric lens 4. The structure of each rhombic prism is shown in fig. 3, the left inclined side face and the right inclined side face are both 45-degree coated reflecting surfaces, and incident light can be parallelly moved for a certain distance through secondary reflection in the prism without changing the propagation direction of the incident light, so that the rhombic prism is also called as a translation prism.
After four target points on the surface of the sample 1 to be measured are reflected twice inside an oblique square prism in sequence, convergence occurs and the target points enter the telecentric lens in a direction parallel to the optical axis of the telecentric lens, namely, a left target point on the surface of the sample 1 to be measured is reflected twice inside a left oblique square prism 6 in sequence, a right target point is reflected twice inside a right oblique square prism 7 in sequence, an upper target point is reflected twice inside an upper oblique square prism 8 in sequence, and a lower target point is reflected twice inside a lower oblique square prism 9 in sequence, convergence occurs and the target points enter the telecentric lens in a direction parallel to the optical axis of the telecentric lens.
A telecentric lens 4 and a digital camera 3 are installed on a tripod 5 bearing the digital camera, the telecentric lens 4 is used for imaging four target points on the surface of the tested sample 1, the telecentric lens 4 simultaneously images upper, lower, left and right target areas on the surface of the tested sample after secondary reflection, and forms a digital image on the target surface of the digital camera, and the characteristic of constant magnification of the telecentric lens 4 is utilized to eliminate the measurement error caused by the out-of-plane displacement of the tested sample 1. The digital camera 3 is used for simultaneously imaging four target points 2 on the surface of the sample 1 to be measured and forming a digital image, namely the digital camera simultaneously shoots four target areas to obtain a digital image, the information of each target area respectively occupies a quarter of the frame of the target surface of the digital camera, so as to realize the simultaneous acquisition of four separated target images, in the embodiment, the four target points 2 are respectively positioned in the left lower area, the right upper area, the left upper area and the right lower area of a digital image chip of the digital camera 3, namely the four target points 2 in the shot digital image respectively occupy 1/4 fields of view, so as to realize the simultaneous acquisition of the images of the left target area, the right target area, the upper target area and the lower target area of the sample, and transmit the shot digital image to the data processing module. The tripod 5, which can carry the digital camera, ensures that the digital camera 3 can be stably carried, and the position of the digital camera 3 can be adjusted within a certain range.
The data processing device comprises a correlation operation module and a post-processing module, wherein the correlation operation module performs correlation operation according to the received digital image to acquire displacement information of the four target points along the measuring direction, and the post-processing module performs calculation by combining the displacement information acquired by the correlation operation module and the distance information of the four target points to acquire local uniform strain information of the surface of the measured sample, namely the two-way strain information of the surface of the measured sample 1.
In this embodiment, the telecentric lens is preferably an object-side telecentric lens or a bilateral telecentric lens, and the larger the magnification ratio, the better. Further, the post-processing module obtains the horizontal uniform strain of the surface of the measured sample as (x)2-x1)/sH，x1And x2Displacement of the first and second target points, s, respectively, in the horizontal directionHThe initial distance between the left target point and the right target point is set; and obtaining the vertical uniform strain magnitude (y) of the surface of the tested sample2-y1)/sV，y1And y2Displacement of the third and fourth target points, respectively, in the vertical direction, sVThe initial distance between the upper and lower target points.
The embodiment of the invention discloses a high-precision biaxial optical extensometer for realizing bidirectional field separation and telecentric lens imaging based on four rhombic prisms, which can eliminate false displacement and false strain caused by out-of-plane displacement of a measured sample, and the generation principle of the false displacement and the strain is shown in figure 4. The imaging of the ordinary camera lens follows a pinhole imaging model, and if a target point is set as a point A far away from an optical axis on the surface of a sample to be detected in the graph of FIG. 4, the point A on the image surface can be imaged through the lens. When the sample point A is moved to the point B by the out-of-plane displacement, the point B on the image surface is imaged according to the pinhole model. Under the condition that a tested sample is not deformed, the image displacement on the image surface, namely the false displacement, is generated by the target point only through the out-of-plane displacement of the tested sample, the size of the false displacement is the distance between the point a and the point b, and strain data, namely the false strain, can be obtained according to the displacement data. Because the telecentric lens observes an object at a parallel visual angle, the magnification ratio is constant in the field depth range, if the telecentric lens is used for replacing a common lens, after the point A moves to the point B, the position of an imaging point on an image surface is unchanged, which shows that the out-of-plane displacement can not cause false displacement and false strain, therefore, the deformation measurement precision of the optical extensometer can be improved.
The invention uses the rhombic prisms to separate the view field and the telecentric lens to image the four target points on the surface of the tested sample, compared with the traditional single camera, the relative positions of the four rhombic prisms are also the horizontal distance between the left target point and the right target point and the vertical distance between the upper target point and the lower target point, namely, the gauge length is adjustable according to the actual requirement, the rhombic prisms with different sizes are selected, and the invention has high flexibility. The distance between two horizontal or vertical target points is closely related to the strain measurement precision, the gauge length can be enlarged by increasing the distance between the two target points, and the precision and the resolution of the strain measurement can be effectively improved under the condition that the relative displacement precision is not changed, so that the high-precision bidirectional strain measurement is realized.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all should be considered as belonging to the protection scope of the invention.
Claims (3)
1. A high precision biaxial optical extensometer utilizing a plurality of rhombic prisms, characterized by comprising: the digital camera comprises a digital camera, a telecentric lens, four rhombic prisms, a fixed flat plate, a tripod for bearing the digital camera and a data processing device; the four rhombic prisms are fixed in the fixed flat plate and are respectively positioned at four directions of the upper part, the lower part, the left side, the right side, the left side and the right side of the fixed flat plate, the left rhombic prism and the right rhombic prism are respectively positioned at the lower side and the upper side of the horizontal straight line, the upper rhombic prism and the lower rhombic prism are respectively positioned at the left side and the right side of the vertical straight line, and the four rhombic prisms are arranged at equal intervals from the central point of the fixed flat;
after four target points on the surface of the tested sample are reflected twice in an oblique square prism in sequence, convergence occurs and the four target points enter the telecentric lens in a direction parallel to the optical axis of the telecentric lens; the telecentric lens simultaneously images upper, lower, left and right target areas on the surface of the sample to be measured after secondary reflection, and forms a digital image on the target surface of the digital camera; the digital camera simultaneously shoots four target areas to obtain a digital image, the shot digital image is transmitted to the data processing module, and the information of each target area occupies one fourth of the target surface of the digital camera, so that the simultaneous acquisition of four separated target images is realized;
the data processing device comprises a correlation operation module and a post-processing module, wherein the correlation operation module acquires displacement information of four target points along a measuring direction according to a received digital image, and the post-processing module acquires local uniform strain information of the surface of the sample to be measured by using the displacement information acquired by the correlation operation module and combining the distance information of the four target points.
2. A high precision biaxial optical extensometer as claimed in claim 1 which utilizes a plurality of rhombic prisms characterized in that: the telecentric lens is an object-side telecentric lens or a bilateral telecentric lens.
3. A high precision biaxial optical extensometer as claimed in claim 1 which utilizes a plurality of rhombic prisms characterized in that: the post-processing module obtains the horizontal uniform strain of the surface of the tested sample as (x)2-x1)/sH，x1And x2Displacement of the first and second target points, s, respectively, in the horizontal directionHThe initial distance between the left target point and the right target point is set; and obtaining the vertical uniform strain magnitude (y) of the surface of the tested sample2-y1)/sV，y1And y2Are respectively third anddisplacement of the fourth target point in the vertical direction, sVThe initial distance between the upper and lower target points.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2762399Y (en) * | 2005-01-01 | 2006-03-01 | 吴砺 | Structure of optica ltransmission in laser |
| EP2286179A2 (en) * | 2008-04-08 | 2011-02-23 | QED Technologies International, Inc. | Stitching of near-nulled subaperture measurements |
| JP2011185725A (en) * | 2010-03-08 | 2011-09-22 | Saga Univ | Device for measurement of displacement or strain |
| CN105758719A (en) * | 2016-04-26 | 2016-07-13 | 河海大学 | Homogeneous strain optical measurement device based on double-mirror reflection and method |
| CN205941958U (en) * | 2016-11-10 | 2017-02-08 | 昂纳信息技术（深圳）有限公司 | Displacement prism subassembly |
| CN107957243A (en) * | 2017-11-21 | 2018-04-24 | 北京航天控制仪器研究所 | For the measuring device of part displacement or deformation quantity in high/low temperature vacuum glass cover |
| CN110763146A (en) * | 2019-10-31 | 2020-02-07 | 河海大学 | High-precision optical extensometer and measuring method based on double cameras |
| CN110806181A (en) * | 2019-10-30 | 2020-02-18 | 河海大学 | High-precision optical extensometer and measuring method based on color camera |
| CN110806182A (en) * | 2019-10-30 | 2020-02-18 | 河海大学 | High-precision optical extensometer and measuring method based on telecentric lens |
| US10663289B2 (en) * | 2016-07-01 | 2020-05-26 | Soochow University | Method and apparatus for detecting concave cylinder and cylindrical diverging lens |
-
2020
- 2020-07-09 CN CN202010659710.0A patent/CN111829446A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2762399Y (en) * | 2005-01-01 | 2006-03-01 | 吴砺 | Structure of optica ltransmission in laser |
| EP2286179A2 (en) * | 2008-04-08 | 2011-02-23 | QED Technologies International, Inc. | Stitching of near-nulled subaperture measurements |
| JP2011185725A (en) * | 2010-03-08 | 2011-09-22 | Saga Univ | Device for measurement of displacement or strain |
| CN105758719A (en) * | 2016-04-26 | 2016-07-13 | 河海大学 | Homogeneous strain optical measurement device based on double-mirror reflection and method |
| US10663289B2 (en) * | 2016-07-01 | 2020-05-26 | Soochow University | Method and apparatus for detecting concave cylinder and cylindrical diverging lens |
| CN205941958U (en) * | 2016-11-10 | 2017-02-08 | 昂纳信息技术（深圳）有限公司 | Displacement prism subassembly |
| CN107957243A (en) * | 2017-11-21 | 2018-04-24 | 北京航天控制仪器研究所 | For the measuring device of part displacement or deformation quantity in high/low temperature vacuum glass cover |
| CN110806181A (en) * | 2019-10-30 | 2020-02-18 | 河海大学 | High-precision optical extensometer and measuring method based on color camera |
| CN110806182A (en) * | 2019-10-30 | 2020-02-18 | 河海大学 | High-precision optical extensometer and measuring method based on telecentric lens |
| CN110763146A (en) * | 2019-10-31 | 2020-02-07 | 河海大学 | High-precision optical extensometer and measuring method based on double cameras |
Non-Patent Citations (3)
| Title |
|---|
| DONG LI等: "《An accurate calibration method for a camera with telecentric lenses》", 《OPTICS AND LASERS IN ENGINEERING》 * |
| 朱飞鹏，等: "《基于二维ＤＩＣ的脆性材料拉伸应力－应变曲线测定》", 《实验力学》 * |
| 朱飞鹏，等: "《基于数字图像相关的光学引伸计应变测量精度研究》", 《光学精密工程》 * |
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