Preparation method of noctilucent speckles applied to light-free condition

Abstract

The invention discloses a noctilucent speckle preparation method applied to a non-illumination condition, and the method comprises the following steps: designing a digital speckle pattern: firstly selecting the diameter size of a digital speckle according to the distance of a target to be measured, and then generating a corresponding digital speckle pattern according to the diameter size of the speckle; the printing ink and the luminous body material are evenly mixed according to the proportion, then the mixed solution is guided into a needle cylinder for standby application, and the particle diameter of the luminous body material is 2-8 micrometers; the mixed solution in the needle cylinder is injected into the ink box through an ink injection hole, air in the ink box is exhausted through a pumping and pressing machine, and then the ink injection hole is blocked through a steel ball; preparing a sample: processing a test piece to be tested into a preset size, and cleaning and drying the surface of the test piece; and speckle spraying: the ink-jet printer prints the solution in the ink box on the tested piece according to the digital speckle pattern. The method has the advantages of simplicity in operation, easiness in implementation, low manufacturing cost and the like.

Description

Technical Field

[0001] The invention relates to the technical field of DIC measurement, and in particular to a method for preparing luminous speckles under no-light conditions. Background Art

[0002] Digital image correlation is an advanced optical technology based on images. It can measure the full-field morphology, displacement and deformation of the surface of an object. The measurement range ranges from microscopic to macroscopic. It has been widely used in many fields such as material science, biomechanics and mechanical manufacturing. It has been recognized as a popular tool for experimental mechanics measurement. It has a simple measurement method and high measurement accuracy. As an information carrier for DIC measurement, speckle needs to have high contrast, disordered speckle size and order, and the surface to be measured must have a high-quality speckle pattern, and it can also deform with the structure.

[0003] At present, the DIC method, which is usually made of fluorescent particles to achieve shape and deformation measurement, is also called fluorescent DIC. Studies have shown that compared with the method of using speckle patterns made of black and white matte paint, it can eliminate mirror reflections, observe the surface structure of objects, and have high-contrast speckle patterns, thereby making the measurement more accurate. It has been widely used in high temperature, composite materials, and battery electrodes. However, this method requires active ultraviolet light irradiation to stimulate the fluorescence on the surface of the measured object so that it can be imaged in the imaging system, which is not suitable for real-time measurement at long distances and at night. Summary of the invention

[0004] The embodiment of the present invention provides a method for preparing luminous speckle under no-light conditions, which is mainly used to solve the problem that nighttime measurement requires real-time nighttime light compensation.

[0005] The specific technical solutions are as follows: In order to solve the above-mentioned technical problems, the present invention is achieved as follows: In a first aspect, a method for preparing luminous speckle under no-light conditions is provided, which comprises the following steps: Design digital speckle pattern: first select the diameter of the digital speckle according to the distance of the target to be measured, and then generate the corresponding digital speckle pattern according to the diameter of the speckle; Prepare solution: Mix the ink and the luminescent material in proportion, and then introduce the mixed solution into a syringe for standby use, wherein the particle diameter of the luminescent material is 2-8 μm; Loading the ink cartridge: Inject the mixed solution in the syringe into the ink cartridge through the ink injection hole, use a pump to expel the air in the ink cartridge, and then use a steel ball to plug the ink injection hole; Prepare the sample: process the test piece into the predetermined size, clean and dry its surface; Spraying speckle: The designed digital speckle pattern is transferred to the inkjet printer through a mobile storage device, and the inkjet printer prints the solution in the ink cartridge on the test piece according to the digital speckle pattern.

[0006] In one embodiment, in the step of designing a digital speckle pattern, the diameter size of the selected digital speckle is to ensure that the size of a single speckle in an imaging picture of a target image acquired by an image acquisition system is controlled within 3-5 pixels.

[0007] In one embodiment, in the step of designing a digital speckle pattern: the image scale of the target to be measured is Xpixel·mm -1 ), in order to obtain the speckle of Ypixel, the diameter size D of the selected digital speckle is (Xpixel) / (Ypixel·mm -1 )), and then generate the corresponding digital speckle pattern in Glare according to the diameter of the speckle.

[0008] In one embodiment, in the step of preparing the solution, the ink and the luminescent material are mixed in a weight ratio of 2:1, introduced into a test tube, stirred for 3-5 minutes using an ultrasonic mixer, and then the mixed solution is introduced into a syringe for use.

[0009] In one embodiment, in the step of cleaning and drying the surface of the tested object, the surface of the tested object is first cleaned with acetone, then wiped clean with a cotton ball, and dried.

[0010] In a second aspect, a method for preparing luminous speckle under no-light conditions is provided, which comprises the following steps: Design digital speckle pattern: first select the diameter of the digital speckle according to the distance of the target to be measured, and then generate the corresponding digital speckle pattern according to the diameter of the speckle; Prepare solution: Mix the ink and the luminescent material evenly according to the proportion, and then introduce the mixed solution into a syringe for standby use, wherein the particle diameter of the luminescent material is greater than 8 μm; Making the luminous substrate: Process the test piece into a predetermined size, clean and dry its surface, and then roll-coat the mixed solution evenly on the surface of the test piece; Spraying speckle: The designed digital speckle pattern is transferred to the inkjet printer through a mobile storage device, and the inkjet printer prints ink on the test piece according to the digital speckle pattern.

[0011] In one embodiment, in the step of designing a digital speckle pattern, the diameter size of the selected digital speckle is to ensure that the size of a single speckle in an imaging picture of a target image acquired by an image acquisition system is controlled within 3-5 pixels.

[0012] In one embodiment, in the step of designing a digital speckle pattern: the image scale of the target to be measured is Xpixel·mm -1 ), in order to obtain the speckle of Ypixel, the diameter size D of the selected digital speckle is (Xpixel) / (Ypixel·mm -1 )), and then generate the corresponding digital speckle pattern in Glare according to the diameter of the speckle.

[0013] In one embodiment, in the step of preparing the solution, the ink and the luminescent material are mixed in a weight ratio of 2:1, introduced into a test tube, stirred for 3-5 minutes using an ultrasonic mixer, and then the mixed solution is introduced into a syringe for use.

[0014] In one embodiment, in the step of cleaning and drying the surface of the tested object, the surface of the tested object is first cleaned with acetone, then wiped clean with a cotton ball, and dried.

[0015] In an embodiment of the present invention, an inkjet solution is prepared by mixing ink with a luminescent material, and a printer prints the inkjet solution on a test piece according to a designed digital speckle pattern, so that no illumination and no energy consumption are required during the printing process. The inkjet solution prepared by the present invention inherits the advantages of fluorescent speckle, can eliminate specular reflection and speckle patterns with high contrast, and has higher measurement accuracy than the classical DIC method, avoiding the problem of "heat wave" phenomenon between the imaging system and the speckle caused by long-term irradiation with an active light source, which leads to increased errors in the measurement results. The present invention has the advantages of simple operation, easy implementation, and low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 This is a flow chart of the steps of the method for preparing luminous speckles under no-light conditions according to Example 1 of the present invention; Figure 2 A schematic diagram of a process of designing speckles in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the process of preparing luminous speckles by the inkjet printer according to Example 1 of the present invention; Figure 4 This is a flow chart of the steps of a method for preparing luminous speckles under no-light conditions according to Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of a process for preparing luminous speckles using a luminescent material as a substrate according to Example 2 of the present invention; Figure 6 This is a luminous speckle pattern in a scene without a light source according to Example 2 of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Long afterglow materials are luminescent materials that first store excitation energy and then release the stored excitation energy in the form of light through heat, light or mechanical energy stimulation after the excitation source stops radiating. They are also called energy storage luminescent materials. Compared with fluorescent materials that rely on real-time excitation, long afterglow materials can last for seconds, hours, or even days. In 1996, a new type of green long afterglow strontium aluminate (SrAl2O4:Eu2+, Dy3+) phosphor was first reported with an afterglow time of up to 20 hours. Since then, long afterglow materials with excellent luminous intensity, high afterglow efficiency and long afterglow time have been widely used in emergency signs, watch dials, luminescent coatings and in vivo imaging.

[0019] The DIC method that uses fluorescent particles to make speckle patterns to achieve shape and deformation measurement is also called fluorescent DIC. Studies have shown that compared with the traditional method of using black and white matte paint to make speckle patterns, it can eliminate mirror reflections, observe the surface structure of objects, and have high-contrast speckle patterns, thereby making the measurement more accurate. It has been widely used in high temperature, composite materials, and battery electrodes. However, unlike long afterglow materials, this method requires active ultraviolet light irradiation to stimulate fluorescence on the surface of the measured object so that it can be imaged in the imaging system. In the scenario of long-distance and real-time measurement at night, the advantages of speckle patterns prepared using long afterglow materials are highlighted.

[0020] The method for preparing luminous speckle under no-light conditions of the present invention uses a long afterglow material to make speckle, which is a DIC measurement method for nighttime without light and energy consumption. From a certain perspective, it is a further extension of fluorescence DIC measurement. It inherits the advantages of fluorescence DIC measurement and supplements the scenes that are difficult to measure with fluorescence DIC. The method for preparing luminous speckle under no-light conditions of the present invention mainly includes the following two preparation methods for luminous materials with different particle sizes, as shown in Example 1 and Example 2. Among them: See also Figures 1 to 3 , Figure 1 is a flowchart of the steps of the method for preparing luminous speckles under no-light conditions according to Example 1 of the present invention, Figure 2This is a schematic diagram of the process of designing speckles in Example 1 of the present invention. Figure 3 This is a schematic diagram of the process of preparing luminous speckles by the inkjet printer of Example 1 of the present invention; as shown in the figure, the luminous speckle preparation method applied to the no-light condition of this embodiment includes the following steps S1 to S5. Among them: Step S1, designing digital speckle pattern: first select the diameter size of digital speckle according to the distance of the target to be measured, and then generate the corresponding digital speckle pattern according to the diameter size of the speckle. The diameter size of the selected digital speckle should ensure that the size of a single speckle in the imaging screen of the target image acquired by the image acquisition system is controlled within 3-5 pixels. The image scale of the target to be measured is Xpixel·mm -1 ), in order to obtain the speckle of Ypixel, the diameter size D of the selected digital speckle is (Xpixel) / (Ypixel·mm -1 ), and then generate the corresponding digital speckle pattern in Glare according to the diameter of the speckle. For example, the image scale is 20pixel·mm -1 In order to obtain a 5-pixel speckle, the diameter of the digital speckle is (5pixel) / (20pixel·mm-1)=0.25mm. Based on this speckle size, the required speckle pattern can be easily output in Glare.

[0021] Step S2, prepare solution: mix the ink and the luminescent material in proportion, and then introduce the mixed solution into a syringe for standby use, wherein the particle diameter of the luminescent material is 2-8μm. For luminescent bodies with a particle diameter of 2-8μm, use a self-prepared mixed solution to prepare the ink cartridge solution, mainly because the ink cartridge is relatively precise and the nozzle outlet diameter cannot be greater than 8μm, otherwise the nozzle will be blocked and the ink cartridge will be scrapped. The ink and the luminescent material are mixed in a weight ratio of 2:1, and introduced into a test tube, stirred for 3-5 minutes using an ultrasonic mixer, and then the mixed solution is introduced into a syringe for standby use.

[0022] Step S3, loading the ink cartridge: inject the mixed solution in the syringe into the ink cartridge through the ink injection hole, use a pump to expel the air in the ink cartridge, and then use a steel ball to plug the ink injection hole. Inject the mixed solution in the syringe into the ink cartridge. Since the selected ink cartridge can only inject 42-44ml of solution, we inject 42ml here to prevent overflow. Then use a pump to expel the air in the ink cartridge. Stop pumping and pressing when the solution just overflows, and use a steel ball to plug the injection hole at the same time.

[0023] Step S4, preparing the sample: processing the test piece into a predetermined size, and cleaning and drying the surface thereof. When cleaning and drying the surface of the test piece, first use acetone to clean the surface of the test piece, then wipe it clean with a cotton ball, and dry it.

[0024] Step S5, spraying speckle: the designed digital speckle pattern is transferred to the inkjet printer through the mobile storage device, and the inkjet printer prints the solution in the ink cartridge on the test piece according to the digital speckle pattern. The digital speckle pattern designed in step S1 is transferred to the inkjet printer through the mobile storage device, and the speckle preparation is completed by printing according to the image.

[0025] The method for preparing luminous speckle under no-light conditions of this embodiment prepares an inkjet solution by mixing ink with a luminescent material, so that no light is required and no energy is consumed in the subsequent printing process. The inkjet solution prepared in this embodiment inherits the advantages of fluorescent speckle, can eliminate specular reflection and speckle patterns with high contrast, and has higher measurement accuracy than the classic DIC method, avoiding the problem of "heat wave" phenomenon between the imaging system and the speckle caused by long-term irradiation with an active light source, resulting in increased error in the measurement results. The preparation method of this embodiment has the advantages of simple operation, easy implementation, and low production cost.

[0026] See also Figures 4 to 6 , Figure 4 is a flowchart of the steps of the method for preparing luminous speckles under no-light conditions according to Example 2 of the present invention, Figure 5 This is a schematic diagram of a process for preparing luminous speckles using a luminescent material as a substrate according to Example 2 of the present invention. Figure 6 This is a luminous speckle diagram in a scene without light source according to Example 2 of the present invention; as shown in the figure, the luminous speckle preparation method for a scene without light source according to this embodiment includes the following steps S1 to S4. Step S1 of this embodiment is the same as step S1 in the above-mentioned Example 1, and the difference between step S2 of this embodiment and step S2 in the above-mentioned Example 1 is the selection of the particle diameter size of the luminescent material, and the particle diameter of the luminescent material in this embodiment is greater than 8 μm.

[0027] Step S3, making a luminescent substrate: process the test piece into a predetermined size, clean and dry its surface, and then roll the mixed solution evenly on the surface of the test piece. Process the material of the test piece into a predetermined size, then clean its surface with acetone, wipe it dry with cotton balls and dry it. After drying, use a brush or roller to roll the solution evenly on the surface of the test piece. It should be noted that the long afterglow luminescence time is related to the particle size and the spraying area, so it is necessary to repeat the spraying many times. Spraying too much at one time will cause the substrate to dry and crack, and bubbles will be generated; spraying too few times will result in a short luminescence time, and the luminescence brightness per unit area will be difficult to complete the DIC calculation process.

[0028] Step S4, spraying speckle: the designed digital speckle pattern is transferred to the inkjet printer through a mobile storage device, and the inkjet printer prints ink on the test piece according to the digital speckle pattern. The digital speckle pattern designed in step S1 is transferred to the inkjet printer through a mobile storage device, and the speckle preparation is completed by printing according to the image.

[0029] The difference between the method for preparing luminous speckle under no-light conditions of the present embodiment and the method for preparing luminous speckle under no-light conditions of the above-mentioned embodiment 1 is that the particle diameter of the luminescent material used in the present embodiment is greater than 8 μm, and the mixed solution of ink and luminescent material is applied to the test piece as a luminescent base. In addition, the inkjet printer of the present embodiment can use an ink cartridge loaded with ordinary black ink.

[0030] In summary, the present invention provides a method for preparing luminous speckle for use in non-lighting conditions, wherein an inkjet solution is prepared by mixing ink with a luminescent material, and a printer prints the inkjet solution on a test piece according to a designed digital speckle pattern, so that no illumination and no energy consumption are required during the printing process. The inkjet solution prepared by the present invention inherits the advantages of fluorescent speckle, can eliminate specular reflection and speckle patterns with high contrast, and has higher measurement accuracy than the classical DIC method, avoiding the problem of "heat wave" phenomenon between the imaging system and the speckle caused by long-term irradiation with an active light source, resulting in increased errors in the measurement results. The present invention has the advantages of simple operation, easy implementation, and low production cost.

[0031] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0032] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for preparing luminous speckle in the absence of light, characterized in that: The following steps are involved: Design digital speckle pattern: first select the diameter of the digital speckle according to the distance of the target to be measured, and then generate the corresponding digital speckle pattern according to the diameter of the speckle; Prepare solution: Mix the ink and the luminescent material in proportion, and then introduce the mixed solution into a syringe for standby use, wherein the particle diameter of the luminescent material is 2-8 μm; Loading the ink cartridge: Inject the mixed solution in the syringe into the ink cartridge through the ink injection hole, use a pump to expel the air in the ink cartridge, and then use a steel ball to plug the ink injection hole; Prepare the sample: process the test piece into the predetermined size, clean and dry its surface; Spraying speckle: The designed digital speckle pattern is transferred to the inkjet printer through a mobile storage device, and the inkjet printer prints the solution in the ink cartridge on the tested piece according to the digital speckle pattern.

2. The method for preparing luminous speckles under no-light conditions according to claim 1, characterized in that: In the step of designing the digital speckle pattern, the diameter size of the selected digital speckle should ensure that the size of a single speckle in the imaging picture of the target image acquired by the image acquisition system is controlled within 3-5 pixels.

3. The method for preparing luminous speckles under no-light conditions according to claim 1, characterized in that: In the step of designing digital speckle pattern: the image scale of the target to be measured is Xpixel·mm -1 In order to obtain the speckle of Ypixel, the diameter size D of the selected digital speckle is (Xpixel) / (Ypixel·mm -1 ), and then generate the corresponding digital speckle pattern in Glare according to the diameter of the speckle.

4. The method for preparing luminous speckles under non-illumination conditions according to claim 1, characterized in that: In the step of preparing the solution, the ink and the luminescent material are mixed at a weight ratio of 2:1, introduced into a test tube, stirred for 3-5 minutes using an ultrasonic mixer, and then the mixed solution is introduced into a syringe for use.

5. The method for preparing luminous speckles under non-illumination conditions according to claim 1, characterized in that: In the step of cleaning and drying the surface of the tested object, the surface of the tested object is first cleaned with acetone, then wiped clean with a cotton ball, and then dried.

6. A method for preparing luminous speckle in the absence of light, characterized in that: The following steps are involved: Design digital speckle pattern: first select the diameter of the digital speckle according to the distance of the target to be measured, and then generate the corresponding digital speckle pattern according to the diameter of the speckle; Prepare solution: Mix the ink and the luminescent material in proportion, and then introduce the mixed solution into a syringe for standby use, wherein the particle diameter of the luminescent material is greater than 8 μm; Making the luminous substrate: processing the tested piece into a predetermined size, cleaning and drying its surface, and then rolling the mixed solution evenly on the surface of the tested piece; Spraying speckle: The designed digital speckle pattern is transferred to the inkjet printer through a mobile storage device, and the inkjet printer prints ink on the test piece according to the digital speckle pattern.

7. The method for preparing luminous speckles in the absence of light according to claim 6, characterized in that: In the step of designing the digital speckle pattern, the diameter size of the selected digital speckle should ensure that the size of a single speckle in the imaging picture of the target image acquired by the image acquisition system is controlled within 3-5 pixels.

8. The method for preparing luminous speckles under non-illumination conditions according to claim 6, characterized in that: In the step of designing digital speckle pattern: the image scale of the target to be measured is Xpixel·mm -1 In order to obtain the speckle of Ypixel, the diameter size D of the selected digital speckle is (Xpixel) / (Ypixel·mm -1 ), and then generate the corresponding digital speckle pattern in Glare according to the diameter of the speckle.

9. The method for preparing luminous speckles under non-illumination conditions according to claim 6, characterized in that: In the step of preparing the solution, the ink and the luminescent material are mixed at a weight ratio of 2:1, introduced into a test tube, stirred for 3-5 minutes using an ultrasonic mixer, and then the mixed solution is introduced into a syringe for use.

10. The method for preparing luminous speckles in the absence of light according to claim 6, characterized in that: In the step of cleaning and drying the surface of the tested object, the surface of the tested object is first cleaned with acetone, then wiped clean with a cotton ball, and then dried.

Images