CN115371950B - Fluorescent color oil flow spectrum three-dimensional reconstruction formula and method suitable for inner pipeline - Google Patents
Fluorescent color oil flow spectrum three-dimensional reconstruction formula and method suitable for inner pipeline Download PDFInfo
- Publication number
- CN115371950B CN115371950B CN202211298493.2A CN202211298493A CN115371950B CN 115371950 B CN115371950 B CN 115371950B CN 202211298493 A CN202211298493 A CN 202211298493A CN 115371950 B CN115371950 B CN 115371950B
- Authority
- CN
- China
- Prior art keywords
- oil flow
- block
- image
- spectrum
- model
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/08—Aerodynamic models
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/06—Measuring arrangements specially adapted for aerodynamic testing
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
The invention relates to the field of wind tunnel color oil flow tests, and particularly discloses a fluorescent color oil flow spectrum three-dimensional reconstruction formula and a method suitable for an inner pipeline. The method dries the dyed resin; weighing a carrier, a diluent and a filler, and uniformly mixing to obtain an oil flow coating; brushing an oil flow coating on the surface of a model area to be tested along the incoming flow direction, and performing a blowing test; dividing the oil flow spectrum on the surface of the model into blocks, recording calibration points, adjusting the angle between the laser and the surface of the model, and illuminating the block to be measured; collecting a photo of a block to be detected; dividing block meshes with the same three-dimensional model data; processing and acquiring an oil flow spectrum photo, intercepting an effective block oil flow image, and projecting the image on a three-dimensional model in a block-by-block manner by referring to a calibration point; and establishing a three-dimensional panoramic color flow spectrum. The invention solves the defects that the acquired oil flow spectrum image is locally unclear and the traditional two-dimensional plane oil flow spectrum can not intuitively reflect the oil flow trace of a space complex model.
Description
Technical Field
The invention belongs to the field of wind tunnel color oil flow tests, and particularly relates to a fluorescent color oil flow spectrum three-dimensional reconstruction formula and method suitable for an inner pipeline.
Background
In wind tunnel tests, the color oil flow technology is a mature and widely-used flow display test technology. According to the technology, an oil agent with tracer particles is coated on the surface of a model, and an oil flow spectrum is generated through interaction of air flow on the surface of the model and an oil film when a wind tunnel runs. Because the oil film is very thin, the viscosity coefficient of the oil film is far larger than that of air, and the pressure gradient of the object surface is not very strong, the color oil flow spectrum actually shows a friction force line spectrum on the object surface in the flowing around. Theoretical calculation and actual observation are carried out to find out singular points such as saddle points, nodes and the like with zero surface friction force and determine the separation position, form, shock wave, vortex position and the like so as to better analyze the aerodynamic characteristics of the model surface.
The Direct Linear Transform (DLT) method is an algorithm for establishing a Linear relationship between the image coordinates of the acquired image and the object space coordinates of the corresponding object points. The method is suitable for images shot by a non-measuring camera, does not need initial values of internal and external orientation elements of the images, can directly convert two-dimensional image point coordinates into object space coordinates, and can analyze data more intuitively. Due to the advantages of simple operation, strong applicability and the like, the DLT method is widely applied to various fields such as surveying and mapping, measurement and the like.
Due to the fact that the type of the wind tunnel, the Mach number of the test incoming flow, the temperature and the total pressure are different, and the viscosity of the oil flow formula with a fixed proportion is single, the conventional oil flow formula cannot meet the existing test. In addition, the model is generally made of metal, and when a camera is used for acquiring an oil flow spectrum image, due to interference of natural light, if specular light reflection is generated, the acquired oil flow spectrum image is locally unclear, and the later analysis is influenced. Moreover, for surfaces with large curvature, the inside of a cavity and the like, oil flow spectrum images are difficult to acquire, and the effect is poor.
Disclosure of Invention
The problem that when a camera is used for acquiring an oil flow spectrum image, the wind tunnel model in the prior art generates mirror light reflection to cause the acquired oil flow spectrum image to be locally unclear and influence later analysis is solved, and the defect that a traditional two-dimensional plane oil flow spectrum cannot visually reflect an oil flow trace line of a space complex model is solved. The invention provides a fluorescent color oil flow spectrum three-dimensional reconstruction formula and a method suitable for an inner pipeline.
The technical scheme of the invention is as follows: the formula consists of 2-5 parts of carrier, 5-8 parts of diluent and 2-6 parts of filler in parts by weight.
The carrier is methyl silicone oil with 50cs viscosity.
The diluent is aviation kerosene.
The filler is dyed resin with the particle size of 100nm to 5 mu m.
In another aspect, the present invention provides a method for three-dimensional reconstruction of a fluorescence color oil flow spectrum of an internal pipe, the method comprising the following steps:
the method comprises the following steps: drying the dyed resin;
step two: weighing the carrier, the diluent and the filler according to the proportion;
step three: uniformly mixing the weighed materials, and sealing for later use to obtain an oil flow coating;
step four: uniformly brushing the uniformly mixed oil flow coating in the third step on the surface of the area of the model to be tested along the incoming flow direction, and carrying out a blowing test;
step five: dividing the oil flow spectrum on the surface of the model into blocks, and recording calibration points;
step six: opening a laser, adjusting the angle between the laser and the surface of the model, and illuminating the block to be measured;
step seven: installing a filter in front of a camera lens, and collecting photos of a block to be detected;
step eight: carrying out histogram equalization processing on the collected original color oil flow image to enhance the image;
step nine: dividing block meshes with the same three-dimensional model data;
step ten: intercepting the oil flow image of the effective block, and projecting the image to the three-dimensional model by referring to the calibration points block by block; and establishing a three-dimensional panoramic color flow spectrum.
The specific operation of the first step is to dry the dyed resin for 2 to 3 hours at a temperature of between 60 and 70 ℃.
And step seven, installing the filter in front of the lens of the single lens reflex, collecting the photos of the block to be detected, and ensuring that the collected images are larger than the divided blocks.
And step ten, projecting the oil flow image of the effective block by using a DLT method.
The formula of the DLT method for projecting the oil flow graph of the effective block is as follows:
，
in this formulax、yCoordinate system coordinates representing the image points, XYZ space coordinates representing object points corresponding to the image points,
are 11 coefficients that exist objectively and are independent of each other.
The invention has the beneficial effects that:
the invention provides a color oil flow coating formula suitable for the working conditions of Mach number ranging from 0.2 to 0.4, and a clear and stable oil flow spectrum can be formed after air blowing. The flow spectrum of the formula oil can radiate fluorescence under the laser irradiation condition so as to facilitate the next acquisition.
According to the data acquisition method of the three-dimensional panoramic color oil flow spectrum, the specific wave band laser is used as a light source, the filter is used for acquiring the specific oil flow trace line, so that the shot image can be shot on the inner surface of the cavity of the model under the condition of no natural illumination, the reflection influence on the surface of the model is eliminated, and the obtained image is clear, high in contrast and universal in applicability. The data processing method of the three-dimensional panoramic color oil flow spectrum, disclosed by the invention, is based on a DLT solution, so that the traditional two-dimensional image is converted into the three-dimensional panoramic color oil flow spectrum, and the data processing method has the advantages of convenience for observing and analyzing the aerodynamic characteristics of the model surface, and clear and accurate image.
Drawings
FIG. 1 is a three-dimensional panoramic color flow spectrum effect chart obtained by using the formula and the method of the invention;
FIG. 2 is a block grid of a three-dimensional blank model according to the method of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in the following specific embodiments. It is to be understood that such description is merely illustrative and not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.
The invention provides a fluorescent color oil flow spectrum three-dimensional reconstruction formula suitable for an inner pipeline, which is combined with attached drawings 1-2, and comprises 2-5 parts of a carrier, 5-8 parts of a diluent and 2-6 parts of a filler in parts by weight. The carrier is methyl silicone oil with 50cs viscosity. The diluent is aviation kerosene. The filler is dyed resin with the particle size of 100nm to 5 mu m. The dyed resin is obtained by dyeing the resin with a dye, and the resin is dyed with a blue dye in the invention.
The invention discloses a fluorescent color oil flow spectrum three-dimensional reconstruction method suitable for an inner pipeline, which comprises the following steps:
the method comprises the following steps: drying the dyed resin; step two: weighing the carrier, the diluent and the filler according to the proportion; step three: uniformly mixing the weighed materials, and sealing for later use to obtain an oil flow coating; step four: uniformly brushing the uniformly mixed oil flow coating in the third step on the surface of the area of the model to be tested along the incoming flow direction, and carrying out a blowing test; step five: dividing the oil flow spectrum on the surface of the model into blocks, and recording calibration points; step six: opening a laser, adjusting the angle between the laser and the surface of the model, and illuminating the block to be measured; step seven: installing a filter in front of a camera lens, and collecting a picture of a block to be detected; step eight: preprocessing the obtained color oil flow spectrum, using self-adaptive histogram equalization, changing the image contrast by calculating the local histogram of the image and then redistributing the brightness so as to highlight details, so that the image is clearer and is convenient to analyze; step nine: dividing block meshes with the same three-dimensional model data; with reference to fig. 2; step ten: intercepting the oil flow image of the effective block, and projecting the image to the three-dimensional model by referring to the calibration points block by block; and establishing a three-dimensional panoramic color flow spectrum. The specific operation of the first step is to dry the dyed resin for 2 to 3 hours at a temperature of between 60 and 70 ℃. The dyed resin has a particle size of 100nm to 5 μm. And step seven, installing the Changtong 495 filter in front of a lens of the single lens reflex, and acquiring photos of the block to be detected to ensure that the acquired images are larger than the divided blocks. And step eight, carrying out histogram equalization processing on the acquired image to enhance the image.
The tenth step is to use the DLT method. Intercepting the oil flow spectrum image subjected to equalization processing according to a block divided by a three-dimensional digital-analog, and rejecting data irrelevant to the block. And clicking the preset reference calibration points of the intercepted oil flow image according to the programmed sequence. And finding out the mapping relation between the two-dimensional image and the space three-dimensional grid by utilizing a DLT basic formula. In this formulax、yCoordinate system coordinates representing the image points, XYZ space coordinates representing object points corresponding to the image points,
the coefficients are 11 coefficients which exist objectively and are independent from each other, and the coefficients can be solved by at least aiming at the reference points so as to find out the matrix mapping relation.
And fitting the corresponding function relationship of the pixel point light intensity by using an engineering interpolation method, thereby solving the problem of discontinuous image light intensity in the two-dimensional to three-dimensional conversion process.
And editing the program based on the DLT principle and the engineering interpolation method. And selecting six reference points of each processed oil flow image by using a program, matching the six reference points with the corresponding reference points of the known three-dimensional model grid, calculating unknown coefficients in the DLT basic formula, projecting the two-dimensional oil flow image on the three-dimensional model block by block, and establishing the three-dimensional panoramic color oil flow spectrum. Repeating the above operations, checking whether the three-dimensional models overlap and collide, and completing the operations after proper adjustment, wherein the effect is shown in fig. 1.
In the prior art, because the wind tunnel types, the test incoming flow Mach number, the temperature and the total pressure are different, and the viscosity of the oil flow formula with a fixed proportion is single, the conventional oil flow formula can not meet the existing test. In addition, the model is generally made of metal, and when a camera is used for acquiring an oil flow spectrum image, due to interference of natural light, if specular light reflection is generated, the acquired oil flow spectrum image is locally unclear, and the later analysis is influenced. Moreover, for surfaces with large curvature, the inside of a cavity and the like, oil flow spectrum images are difficult to acquire, and the effect is poor. The formula of the color oil flow coating suitable for the working conditions of Mach number ranging from 0.2 to 0.4 can form a clear and stable oil flow spectrum after blowing. The formula oil flow spectrum can radiate fluorescence under the laser irradiation condition, the reflected light on the surface of a metal material is filtered by a filter, only excited fluorescence is reserved, so that the next image acquisition is facilitated, and the technical resistance is overcome.
The invention relates to a fluorescent color oil flow spectrum three-dimensional reconstruction method suitable for an inner pipeline, which particularly takes laser with a specific waveband as a light source, utilizes a filter to collect a specific oil flow trace line, enables a shot image to be taken on the inner surface of a cavity of a model under the condition of no natural illumination, eliminates the reflection influence on the surface of the model, obtains clear images with high contrast, can be applied to color tests of various wind tunnels, is not influenced by the model and the environment, and has universal applicability.
Example 1
The formula consists of 2 parts of carrier, 5 parts of diluent and 2 parts of filler in parts by weight. The carrier is methyl silicone oil with 50cs viscosity. The diluent is aviation kerosene. The filler is a dyed resin with a particle size of 100nm mu m.
The formula is applied to a fluorescent color oil flow spectrum three-dimensional reconstruction method suitable for an inner pipeline, and the method specifically comprises the following steps:
the method comprises the following steps: drying the dyed resin for 2 hours at the temperature of 60 ℃; step two: pressing a carrier by an electronic scale: diluent agent: filler =2:5:2, weighing the materials in proportion; step three: mixing the weighed materials in a beaker, fully stirring the materials by using a glass rod, and sealing the mixture for later use; step four: uniformly brushing the oil flow coating on the surface of the model area to be tested along the flowing direction by using a brush, and carrying out a blowing test; step five: dividing the oil flow spectrum on the surface of the model into blocks, and recording calibration points; step six: opening a laser, adjusting the angle between the laser and the surface of the model, and illuminating the block to be measured; step seven: installing a Changtong 495nm filter in front of a lens of a single lens reflex, collecting photos of a block to be detected, and ensuring that a collected image is larger than a divided block; step eight: processing the collected original color oil flow image to enhance the image; step nine: carrying out same block mesh division on the three-dimensional model data; step ten: and intercepting the oil flow image of the effective block by utilizing a program written based on a DLT (digital Living transform) solution, and projecting the image to the three-dimensional model by referring to the calibration points block by block to establish a three-dimensional panoramic color oil flow spectrum.
Example 2
The difference between the embodiment and the embodiment 1 is that the fluorescent color oil flow spectrum three-dimensional reconstruction formula suitable for the inner pipeline is composed of a carrier, a diluent and a filler, and the carrier is 5 parts by weight, the diluent is 8 parts by weight and the filler is 6 parts by weight.
Example 3
The difference between the embodiment and the embodiment 1 is that the fluorescent color oil flow spectrum three-dimensional reconstruction formula suitable for the inner pipeline is composed of 4 parts of carrier, 6 parts of diluent and 5 parts of filler in parts by weight.
The specific protection scope of the present invention is not limited to the above explanation, and any simple replacement or modification within the technical spirit of the present invention and technical solution according to the present invention should be within the protection scope of the present invention.
Claims (6)
1. A method for three-dimensional reconstruction of a fluorescent color oil flow spectrum for an internal pipe, the method comprising the steps of:
the method comprises the following steps: drying the dyed resin;
step two: weighing the carrier, the diluent and the filler according to the proportion;
step three: uniformly mixing the weighed materials, and sealing for later use to obtain an oil flow coating;
step four: uniformly brushing the uniformly mixed oil flow coating in the third step on the surface of the area of the model to be tested along the incoming flow direction, and carrying out a blowing test;
step five: dividing the oil flow spectrum on the surface of the model into blocks, and recording calibration points;
step six: turning on a laser, adjusting the angle between the laser and the surface of the model, and illuminating the to-be-measured area;
step seven: installing a filter in front of a camera lens, and collecting photos of a block to be detected;
step eight: processing the collected original color oil flow image to enhance the image;
step nine: dividing block meshes with the same three-dimensional model data;
step ten: intercepting the oil flow image of the effective block, and projecting the image to the three-dimensional model by referring to the calibration points block by block; establishing a three-dimensional panoramic color flow spectrum; drying the dyed resin at 60-70 ℃ for 2-3 hours; the seventh step is that the filter is arranged in front of the lens of the single lens reflex to collect the photos of the block to be measured,
ensuring that the collected image is larger than the division block;
the three-dimensional reconstruction method is realized on the basis of a fluorescent color oil flow spectrum three-dimensional reconstruction formula of an inner pipeline, wherein the formula consists of 2-5 parts of a carrier, 5-8 parts of a diluent and 2-6 parts of a filler in parts by weight; the filler is dyed resin with the particle size of 100 nm-5 mu m.
2. The method of claim 1, wherein the carrier is methyl silicone oil with a viscosity of 50 cs.
3. The method for three-dimensional reconstruction of fluorescence color oil spectra for internal pipelines according to claim 1, wherein the diluent is aviation kerosene.
4. The method of claim 3, wherein the formulation is a color oil flow coating applied to Mach number range of 0.2-0.4.
5. The method for three-dimensional reconstruction of fluorescence color oil flow spectrum for internal pipe according to claim 1, wherein the step ten is to project an effective block oil flow image by using DLT method.
6. The method for three-dimensional reconstruction of fluorescence color oil flow spectrum applicable to the inner pipeline according to claim 5, wherein the DLT method intercepts the oil flow diagram of the effective block according to the formula:
in the formula, x and y represent coordinate of coordinate apparatus of image point, XYZ represents space coordinate of object point corresponding to image point, and L 1 ～L 11 Are 11 coefficients that exist objectively and are independent of each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211298493.2A CN115371950B (en) | 2022-10-21 | 2022-10-21 | Fluorescent color oil flow spectrum three-dimensional reconstruction formula and method suitable for inner pipeline |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211298493.2A CN115371950B (en) | 2022-10-21 | 2022-10-21 | Fluorescent color oil flow spectrum three-dimensional reconstruction formula and method suitable for inner pipeline |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115371950A CN115371950A (en) | 2022-11-22 |
| CN115371950B true CN115371950B (en) | 2023-01-17 |
Family
ID=84072865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211298493.2A Active CN115371950B (en) | 2022-10-21 | 2022-10-21 | Fluorescent color oil flow spectrum three-dimensional reconstruction formula and method suitable for inner pipeline |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115371950B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107091722A (en) * | 2017-04-20 | 2017-08-25 | 中国人民解放军国防科学技术大学 | A kind of Flow Field in Wind Tunnel observation system |
| CN108613791A (en) * | 2018-05-29 | 2018-10-02 | 南京航空航天大学 | A kind of incident shock three-dimensional structure measurement apparatus and measurement method |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102564723B (en) * | 2011-12-14 | 2014-08-06 | 中国航空工业集团公司沈阳空气动力研究所 | Formula of oil for color oil flow test of low-speed wind tunnel |
| CN104849018A (en) * | 2015-04-29 | 2015-08-19 | 中国航空工业集团公司哈尔滨空气动力研究所 | Three-component oil for colorful oil flow test of low-speed wind tunnel |
| CN104824081A (en) * | 2015-05-26 | 2015-08-12 | 龚柱 | Design method for cooker support of cooker used for manufacturing fried bread sticks |
| CN106840576A (en) * | 2017-03-10 | 2017-06-13 | 中国空气动力研究与发展中心高速空气动力研究所 | High-speed wind tunnel oil stream test method |
| CN108760225A (en) * | 2018-04-03 | 2018-11-06 | 西北工业大学 | A kind of oil stream formula of the high-speed wind tunnel oil stream experiment of clearly calibration range of Mach numbers |
| CN110987356A (en) * | 2019-12-06 | 2020-04-10 | 中国航空工业集团公司沈阳空气动力研究所 | Formula and using method of colored oil flow suitable for subsonic velocity temporary flushing wind tunnel |
| CN111811769B (en) * | 2020-06-16 | 2021-08-06 | 南京航空航天大学 | Three-dimensional internal rotation type air inlet channel real-time oil flow display method with wave-rider precursor |
-
2022
- 2022-10-21 CN CN202211298493.2A patent/CN115371950B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107091722A (en) * | 2017-04-20 | 2017-08-25 | 中国人民解放军国防科学技术大学 | A kind of Flow Field in Wind Tunnel observation system |
| CN108613791A (en) * | 2018-05-29 | 2018-10-02 | 南京航空航天大学 | A kind of incident shock three-dimensional structure measurement apparatus and measurement method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115371950A (en) | 2022-11-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102297660B (en) | Measuring method of shield tunnel lining segment seam open width and apparatus thereof | |
| CN102183214B (en) | Light detection method for large-aperture aspherical mirror structure | |
| Le Sant et al. | Surface pressure measurements by using pressure-sensitive paints | |
| CN107403177A (en) | Brightness measurement method based on industrial camera | |
| Winnemöller et al. | Light waving: Estimating light positions from photographs alone | |
| CN109612512B (en) | Multi-mode integrated test platform and test method for space-based photoelectric system | |
| Ciortan et al. | A practical reflectance transformation imaging pipeline for surface characterization in cultural heritage | |
| CN110514392A (en) | Temperature deformation measuring system and method based on wide-angle lens and image distortion correction | |
| CN114283203A (en) | Calibration method and system of multi-camera system | |
| Powell et al. | Development of unsteady-PSP data processing and analysis tools for the NASA AMES UNITary 11ft wind tunnel | |
| CN113030510A (en) | Three-dimensional flow field testing method and system based on three-color mask single-color camera | |
| CN115371950B (en) | Fluorescent color oil flow spectrum three-dimensional reconstruction formula and method suitable for inner pipeline | |
| CN110288711A (en) | The detection method of bituminous pavement three-D grain pattern | |
| CN108007382B (en) | Surface shape measurement device and method based on Structured Illumination | |
| Sole et al. | Image based reflectance measurement based on camera spectral sensitivities | |
| CN114858404A (en) | Global surface frictional resistance testing method based on optical flow algorithm | |
| CN115546320A (en) | Camera calibration and online ice shape measurement method for measuring ice shape | |
| CN110298082B (en) | Method for obtaining coating bidirectional reflection distribution function simulation parameters through imaging method | |
| Bencic | Experiences using pressure sensitive paint in NASA Lewis Research Center propulsion test facilities | |
| Shimbo et al. | Evaluation of several calibration techniques for pressure sensitive paint in transonic testing | |
| CN111750995B (en) | Spectrum measurement method for open measurement environment application | |
| Dong et al. | Three-dimensional pressure field measurement on turbine guide vanes using a dynamic distortion correction endoscopic pressure-sensitive paint technique | |
| CN114509203B (en) | Fusion method for PSP (pressure sensitive protocol) measurement pressure of test model surface | |
| Sitnik et al. | Processing paths from integrating multimodal 3D measurement of shape, color and BRDF | |
| CN117249967B (en) | Pressure and temperature synchronous measurement method based on two-component pressure-sensitive paint technology |
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 |