CN109887037B - Calibration method suitable for oblique laser interferometry lens imaging distortion - Google Patents
Calibration method suitable for oblique laser interferometry lens imaging distortion Download PDFInfo
- Publication number
- CN109887037B CN109887037B CN201910058504.1A CN201910058504A CN109887037B CN 109887037 B CN109887037 B CN 109887037B CN 201910058504 A CN201910058504 A CN 201910058504A CN 109887037 B CN109887037 B CN 109887037B
- Authority
- CN
- China
- Prior art keywords
- flat metal
- interference image
- measured
- measured surface
- simulation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Length Measuring Devices By Optical Means (AREA)
- Instruments For Measurement Of Length By Optical Means (AREA)
Abstract
The invention discloses a calibration method suitable for oblique laser interferometry lens imaging distortion, which comprises the following specific steps: firstly, establishing a mathematical model of a measured surface of a flat metal; obtaining a simulation interference image of the measured surface of the flat metal by using a simulation method of light path ray tracing calculation through the established mathematical model; acquiring an actual measurement image of a measured surface of the flat metal by using a laser interferometry system; the obtained simulation interference image of the measured surface of the flat metal is compared with the actual measured image of the measured surface of the flat metal respectively, so that a calibration method for lens imaging distortion in the inclined laser interference measurement is established, and the defect that no directly available lens imaging distortion correction method exists in the current inclined laser interference measurement system is overcome.
Description
Technical Field
The invention belongs to the technical field of laser interferometry, and relates to a calibration method suitable for imaging distortion of an oblique laser interferometry lens.
Background
Laser interferometry is one of the methods of modern precision measurement techniques. In the current slant entry type laser interferometry, interference fringes acquired by measuring complex curved surfaces such as gears are seriously deformed, and the main reasons are three. The problem of distortion and deformation of an interference fringe pattern caused by compression and deformation of the interference fringe pattern along the direction of an optical axis due to the fact that a laser beam is reflected by the surface of an object after being bent and plane waves are scattered can be solved through an optical simulation method; deformation research caused by the distortion characteristics of the imaging lens is less, and no effective solution exists. At present, the distortion correction methods mainly include a conventional calibration method, a self-calibration method and an active vision calibration method. In terms of the oblique laser interferometry, the existing distortion correction method has the defect that the self-calibration method and the active vision calibration method cannot be applied to laser interferometry with a basically fixed imaging system, and the traditional camera calibration method is difficult to be directly applied. Therefore, a calibration method for lens imaging distortion is needed to solve the problems of image deformation and low reliability of image registration precision caused by imaging lens distortion characteristics in the current oblique laser interferometry.
Disclosure of Invention
The invention aims to provide a calibration method suitable for imaging distortion of a lens in inclined laser interferometry, and solves the problems that no directly available lens imaging distortion calibration method exists in inclined laser interferometry and image registration accuracy and reliability are low.
The invention adopts the technical scheme that the calibration method is suitable for the imaging distortion of the inclined laser interferometry lens, and comprises the following specific steps:
step 2, obtaining a simulation interference image of the measured surface of the flat metal by a simulation method of light path ray tracing calculation through the mathematical model established in the step 1;
step 3, collecting an actual measurement interference image of the measured surface of the flat metal by using a laser interference measurement system;
and 4, respectively comparing the simulation interference image of the measured surface of the flat metal obtained in the steps 2 and 3 with the actual measurement interference image of the measured surface of the flat metal, and establishing a calibration method of lens imaging distortion in the inclined laser interference measurement.
The invention is also characterized in that:
wherein the step 1 specifically comprises the following steps: selecting a rectangular flat metal of a standard part as an object, placing a measured surface of the flat metal at a measured position, wherein the measured surface of the flat metal is averagely divided into M parts according to an x-axis direction, averagely divided into N parts according to a y-axis direction, and the measured surface of the flat metal is divided into (M + 1) (N + 1) grid points, any grid point can be represented as V (M, N), wherein M =0,1,2, …, M, N =0,1,2, …, N, and the coordinate value of each grid point of the measured surface of the flat metal is represented as:
wherein the length of the flat metal is L, the width of the flat metal is W, and M and N are positive integers;
wherein the step 2 specifically comprises the following steps: obtaining a simulation interference image of the metal measured surface of the measured flat plate by using a simulation method of light path ray tracing calculation, wherein the simulation interference image point is represented as V' (m, n);
wherein the step 3 specifically comprises the following steps: placing the flat metal in a laser interference measurement system, realizing item shifting by controlling the movement of piezoelectric ceramic PZT, and collecting an actually measured interference image of the measured surface of the flat metal by using a CCD camera;
wherein the step 4 specifically comprises the following steps: comparing the simulated interference image obtained in the step 2 and the step 3 with the measured interference image of the flat metal, and defining a calibration matrix E as follows:
wherein M =0,1,2, …, M, N =0,1,2, …, N,
and
respectively, the coordinates of the R-th row before and after the simulation interference image is calibrated by using the calibration matrix E,
and
respectively, the coordinates of the S-th column before and after the simulation interference image is calibrated by using the calibration matrix E R For simulating the Rth line of the interference imageAngle of rotation, beta S A rotation angle of the S column of the simulated interference image;
calculating the parameter alpha of the calibration matrix by comparing and analyzing the images R And beta S The formula is as follows:
wherein alpha is 0 Simulating the included angle alpha between the interference image boundary cd and the actually measured object boundary cd for the flat metal M Simulating the included angle beta between the interference image boundary ab and the actually measured object boundary ab for the flat metal 0 An included angle beta between the boundary ad of the plate metal simulation interference image and the boundary ad of the actual measurement object N An included angle between a flat metal simulation interference image boundary bc and an actually measured object boundary bc is formed; therefore, the calibration of lens imaging distortion in the oblique laser interferometry is completed.
The invention has the beneficial effects that:
the calibration method for the imaging distortion of the lens in the inclined laser interferometry system provided by the invention is used for analyzing by taking a standard part as an object, provides a calibration method for the imaging distortion of the lens in the laser interferometry system, and overcomes the defect that no directly available lens imaging distortion correction method exists in the existing inclined laser interferometry system.
Drawings
FIG. 1 is a diagram of a flat metal grid point of a calibration method for imaging distortion of an oblique laser interferometry lens according to the present invention;
FIG. 2 is a boundary diagram of an effective measurement area in a registration result diagram before lens imaging distortion calibration, which is suitable for a calibration method for oblique laser interferometry lens imaging distortion of the present invention;
FIG. 3 is a registration graph of a simulated interference image and an actually measured interference image in a registration result graph before lens imaging distortion calibration, which is suitable for the calibration method of imaging distortion of an inclined laser interferometry lens of the invention;
FIG. 4 is a boundary diagram of an effective measurement area in a registration result diagram after lens imaging distortion calibration, which is suitable for a calibration method for imaging distortion of an inclined laser interferometry lens of the invention;
FIG. 5 is a diagram showing registration of a simulated interference image and an actually measured interference image in a registration result image after calibration of lens imaging distortion, which is applicable to a calibration method for oblique laser interferometry lens imaging distortion.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
The invention relates to a calibration method suitable for oblique laser interferometry lens imaging distortion, which adopts a laser interferometry system, takes a standard part rectangular flat metal with a smooth surface as an object, and calibrates the lens imaging distortion, and specifically comprises the following steps:
establishing a mathematical model of the flat metal: selecting a rectangular flat metal plate of a standard part as an object, and placing a measured surface of the flat metal plate at the same position as a measured tooth surface in the gear measuring process, wherein the centers of the measured surface are overlapped; the measured surface of the flat metal is averagely divided into M parts in the x-axis direction, and averagely divided into N parts in the y-axis direction, the measured surface of the flat metal is divided into (M + 1) (N + 1) grid points, and the grid points are uniformly distributed as shown in figure 1; any one grid point may be denoted as V (M, N), where M =0,1,2, …, M, N =0,1,2, …, N, and the coordinate value of each grid point of the flat sheet metal surveyed surface is expressed as:
wherein the length of the flat metal is L, the width of the flat metal is W, and M and N are positive integers;
step 2, obtaining a simulation interference image of the measured surface of the flat metal: obtaining a simulation interference image of the measured surface of the measured flat metal by using a simulation method of light path ray tracing calculation, wherein the simulation interference image point is represented as V' (m, n) for the purpose of comparing with the measured interference image;
step 3, collecting an actually measured interference image of the measured surface of the flat metal: placing the flat metal in the same position of a laser interference measurement system as the measured tooth surface, realizing item shifting by controlling the movement of the piezoelectric ceramic PZT, and collecting an actual measurement interference image of the measured surface of the flat metal by using a CCD camera;
step 4, calibrating imaging distortion of the lens: comparing the simulated interference image obtained in the step 2 and the step 3 with the measured interference image of the flat metal, and defining a calibration matrix E as follows:
wherein M =0,1,2, …, M, N =0,1,2, …, N,
and
respectively, the coordinates of the R-th row before and after the simulation interference image is calibrated by using the calibration matrix E,
and
respectively, the coordinates of the S-th column before and after the simulation interference image is calibrated by using the calibration matrix E R For simulating the rotation angle, beta, of the R-th line of the interference image S The rotation angle of the S-th column of the simulated interference image.
By analyzing the image contrast, calculatingParameter α of the calibration matrix R And beta S The formula is as follows:
wherein alpha is 0 The angle between the boundary cd of the interference image and the boundary cd of the actually measured object is simulated by the flat metal, alpha M Simulating the included angle beta between the interference image boundary ab and the actually measured object boundary ab for the flat metal 0 An included angle beta between the boundary ad of the plate metal simulation interference image and the boundary ad of the actual measurement object N An included angle between a flat metal simulation interference image boundary bc and an actually measured object boundary bc is formed;
therefore, the calibration of lens imaging distortion in the oblique laser interferometry is completed.
And (3) feasibility experiment verification: selecting a gear to be measured as an object, placing the gear to be measured in a laser interference measurement system, placing the tooth surface to be measured and a flat metal surface to be measured at the same measurement position, and obtaining a simulation interference image of the tooth surface of the gear to be measured by utilizing a simulation method of light path ray tracing calculation. And placing the measured tooth surface and the measured surface of the flat metal at the same measuring position, and collecting the actual measurement interference image of the measured surface of the gear by using a CCD camera. Before the distortion calibration of the lens imaging, the actually measured interference image and the simulated interference image in the laser interference measurement process are registered as shown in fig. 2 and 3. The calibration method suitable for the oblique laser interferometry lens imaging distortion is applied, the actual measurement interference image and the simulation interference image are registered after the lens imaging distortion is calibrated as shown in figures 3 and 4, and by comparison, the image registration is carried out by using the calibration method disclosed by the invention, so that the shapes of the actual measurement interference image and the simulation interference image are more consistent, and the image registration effect is better.
Claims (4)
1. A calibration method suitable for oblique laser interferometry lens imaging distortion is characterized by comprising the following specific steps:
step 1, establishing a mathematical model of a measured surface of a flat metal: selecting a rectangular flat metal of a standard part as an object, placing a measured surface of the flat metal at a measured position, wherein the measured surface of the flat metal is averagely divided into M parts according to an x-axis direction, averagely divided into N parts according to a y-axis direction, and the measured surface of the flat metal is divided into (M + 1) (N + 1) grid points, any grid point can be represented as V (M, N), wherein M =0,1,2, …, M, N =0,1,2, …, N, and the coordinate value of each grid point of the measured surface of the flat metal is represented as:
wherein the length of the flat metal is L, the width of the flat metal is W, and M and N are positive integers;
step 2, obtaining a simulation interference image of the measured surface of the flat metal by using a simulation method of light path ray tracing calculation through the mathematical model established in the step 1;
step 3, collecting an actually measured interference image of the measured surface of the flat metal by using a laser interference measurement system;
and 4, respectively comparing the simulation interference image of the measured surface of the flat metal obtained in the steps 2 and 3 with the actual measurement interference image of the measured surface of the flat metal, and establishing a calibration method of lens imaging distortion in the inclined laser interference measurement.
2. The method for calibrating imaging distortion of an oblique laser interferometry lens according to claim 1, wherein the step 2 specifically comprises: and obtaining a simulated interference image of the metal measured surface of the measured flat plate by using a simulation method of light path ray tracing calculation, wherein the point of the simulated interference image is represented as V' (m, n).
3. The method for calibrating imaging distortion of an oblique laser interferometry lens according to claim 1, wherein the step 3 specifically comprises: the method comprises the steps of placing the flat metal in a laser interference measurement system, realizing item shifting by controlling the movement of piezoelectric ceramics PZT, and collecting an actual measurement interference image of a measured surface of the flat metal by using a CCD camera.
4. The method for calibrating imaging distortion of an oblique laser interferometry lens according to claim 1, wherein the step 4 specifically comprises: comparing the simulated interference image obtained in the step 2 and the step 3 with the measured interference image of the flat metal, and defining a calibration matrix E as follows:
wherein M =0,1,2, …, M, N =0,1,2, …, N,
and
respectively, the coordinates of the R-th row before and after the simulation interference image is calibrated by using the calibration matrix E,
and
respectively, the coordinates of the S-th column before and after the simulation interference image is calibrated by using the calibration matrix E R For simulating the rotation angle, beta, of the R-th line of the interference image S A rotation angle of the S column of the simulated interference image;
calculating the parameter alpha of the calibration matrix by comparing and analyzing the images R And beta S The formula is as follows:
wherein alpha is 0 Simulating the included angle alpha between the interference image boundary and the actually measured object boundary for the flat metal M Simulating interference image boundary and actually measured object boundary for flat metalAngle of separation, beta 0 Is the included angle beta between the boundary of the plate metal simulation interference image and the boundary of the actual measurement object N The included angle between the boundary of the flat metal simulation interference image and the boundary of the actually measured object is obtained; therefore, the calibration of lens imaging distortion in the oblique laser interferometry is completed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910058504.1A CN109887037B (en) | 2019-01-22 | 2019-01-22 | Calibration method suitable for oblique laser interferometry lens imaging distortion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910058504.1A CN109887037B (en) | 2019-01-22 | 2019-01-22 | Calibration method suitable for oblique laser interferometry lens imaging distortion |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109887037A CN109887037A (en) | 2019-06-14 |
| CN109887037B true CN109887037B (en) | 2023-03-14 |
Family
ID=66926561
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910058504.1A Active CN109887037B (en) | 2019-01-22 | 2019-01-22 | Calibration method suitable for oblique laser interferometry lens imaging distortion |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109887037B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102288122A (en) * | 2011-04-22 | 2011-12-21 | 中国航空工业集团公司北京长城计量测试技术研究所 | Online calibrating device and method for fiber Bragg grating (FBG) strain sensor |
| CN102322816A (en) * | 2011-06-13 | 2012-01-18 | 北京航空航天大学 | Calibration target device and calibration method for three-dimensional ice-shaped digital image system |
| ES2391510A1 (en) * | 2011-04-29 | 2012-11-27 | Consejo Superior De Investigaciones Científicas (Csic) | Method for calibrating and correcting the scanning distortion of an optical coherence tomography system |
| CN103499297A (en) * | 2013-10-25 | 2014-01-08 | 爱科维申科技（天津）有限公司 | CCD (Charge Coupled Device)-based high-accuracy measuring method |
| CN104215261A (en) * | 2014-08-26 | 2014-12-17 | 中国科学院长春光学精密机械与物理研究所 | Distortion calibrating method for large-field reflex free form surface space camera |
| CN104284103A (en) * | 2014-09-26 | 2015-01-14 | 国家电网公司 | Calibration method of internal parameters of thermal infrared camera |
| CN105841633A (en) * | 2016-05-23 | 2016-08-10 | 电子科技大学 | Large-area optical profile measurement calibration method based on double-wave-surface interference fringe array |
| CN106017871A (en) * | 2016-06-23 | 2016-10-12 | 中国科学院长春光学精密机械与物理研究所 | High-precision large-aperture optical lens distortion calibration device and calibration method |
| CN106091978A (en) * | 2016-06-01 | 2016-11-09 | 西安工程大学 | The joining method of interference fringe image in inclined in type measurements by laser interferometry |
| CN107121109A (en) * | 2017-06-12 | 2017-09-01 | 北京航空航天大学 | A kind of structure light parameter calibration device and method based on preceding plated film level crossing |
| CN108428251A (en) * | 2018-03-09 | 2018-08-21 | 深圳市中捷视科科技有限公司 | One kind being based on machine vision technique laser structure light automatic calibration method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4451221B2 (en) * | 2004-06-04 | 2010-04-14 | 東京エレクトロン株式会社 | Gas processing apparatus and film forming apparatus |
-
2019
- 2019-01-22 CN CN201910058504.1A patent/CN109887037B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102288122A (en) * | 2011-04-22 | 2011-12-21 | 中国航空工业集团公司北京长城计量测试技术研究所 | Online calibrating device and method for fiber Bragg grating (FBG) strain sensor |
| ES2391510A1 (en) * | 2011-04-29 | 2012-11-27 | Consejo Superior De Investigaciones Científicas (Csic) | Method for calibrating and correcting the scanning distortion of an optical coherence tomography system |
| CN102322816A (en) * | 2011-06-13 | 2012-01-18 | 北京航空航天大学 | Calibration target device and calibration method for three-dimensional ice-shaped digital image system |
| CN103499297A (en) * | 2013-10-25 | 2014-01-08 | 爱科维申科技（天津）有限公司 | CCD (Charge Coupled Device)-based high-accuracy measuring method |
| CN104215261A (en) * | 2014-08-26 | 2014-12-17 | 中国科学院长春光学精密机械与物理研究所 | Distortion calibrating method for large-field reflex free form surface space camera |
| CN104284103A (en) * | 2014-09-26 | 2015-01-14 | 国家电网公司 | Calibration method of internal parameters of thermal infrared camera |
| CN105841633A (en) * | 2016-05-23 | 2016-08-10 | 电子科技大学 | Large-area optical profile measurement calibration method based on double-wave-surface interference fringe array |
| CN106091978A (en) * | 2016-06-01 | 2016-11-09 | 西安工程大学 | The joining method of interference fringe image in inclined in type measurements by laser interferometry |
| CN106017871A (en) * | 2016-06-23 | 2016-10-12 | 中国科学院长春光学精密机械与物理研究所 | High-precision large-aperture optical lens distortion calibration device and calibration method |
| CN107121109A (en) * | 2017-06-12 | 2017-09-01 | 北京航空航天大学 | A kind of structure light parameter calibration device and method based on preceding plated film level crossing |
| CN108428251A (en) * | 2018-03-09 | 2018-08-21 | 深圳市中捷视科科技有限公司 | One kind being based on machine vision technique laser structure light automatic calibration method |
Non-Patent Citations (2)
| Title |
|---|
| Automated Simultaneous Calibration of a Multi-View Laser Stripe Profiler;W. Stocher等;《IEEE》;20060110;第4424-4429页 * |
| 一种用于结构光测量系统的投影仪标定技术;王衡等;《信息技术》;20160325;第36-40页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109887037A (en) | 2019-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110296667B (en) | High-reflection surface three-dimensional measurement method based on line structured light multi-angle projection | |
| CN110672037A (en) | Linear light source grating projection three-dimensional measurement system and method based on phase shift method | |
| CN109307480B (en) | Method for detecting multi-surface shape of transmission element | |
| CN106959075B (en) | Method and system for accurate measurement using a depth camera | |
| CN107860337B (en) | Structured light three-dimensional reconstruction method and device based on array camera | |
| CN110864650A (en) | Flatness measuring method based on fringe projection | |
| WO2020199439A1 (en) | Single- and dual-camera hybrid measurement-based three-dimensional point cloud computing method | |
| CN109870111B (en) | Involute cylindrical gear tooth pitch accumulated error measuring method based on machine vision | |
| Li et al. | Light plane calibration and accuracy analysis for multi-line structured light vision measurement system | |
| CN109443214B (en) | Calibration method and device, measurement method and device for structured light three-dimensional vision | |
| CN108195314B (en) | Reflective striped three dimension profile measurement method based on more field stitchings | |
| CN111598931B (en) | Monocular vision system imaging parameter calibration device and method | |
| CN107941168A (en) | Reflective stripe surface shape measuring method and device based on speckle position calibration | |
| CN101666625B (en) | Model-free method for correcting distortion error | |
| CN110146032B (en) | Synthetic aperture camera calibration method based on light field distribution | |
| CN114199160B (en) | Circuit board component geometry detection method based on binary code grating defocusing projection | |
| CN112985258B (en) | Calibration method and measurement method of three-dimensional measurement system | |
| CN110428471A (en) | A kind of accurate method for self-locating for the measurement of freeform optics surface sub-aperture deviation | |
| CN112179292B (en) | Projector-based line structured light vision sensor calibration method | |
| CN109887037B (en) | Calibration method suitable for oblique laser interferometry lens imaging distortion | |
| CN109506562A (en) | A kind of Binocular vision photogrammetry device for the detection of solar wing spreading lock depth | |
| CN209706766U (en) | Inverse Hartmann's optical path wafer surface roughness measuring device | |
| CN116379965A (en) | Structured light system calibration method and device, structured light system and storage medium | |
| CN115046497A (en) | Improved calibration method based on grating projection measurement system | |
| CN105427302A (en) | Three-dimensional acquisition and reconstruction system based on mobile sparse camera acquisition array |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |