High-precision light-induced positioning method

Abstract

The invention discloses a high-precision light-induced positioning method, and relates to the technical field of light spot imaging. Comprising a base material, and the surface of the base material is provided with randomly distributed photoluminescent particles; an excitation light source can uniformly irradiate the surface of the base material, so that the photoluminescence particles on the surface of the base material generate photoluminescence after being excited, luminous patterns are generated on the surface of the base material, and the movement distance is determined by comparing the luminous patterns collected before and after movement. The method has the advantages that light emitted by the excitation light source irradiates on the photoluminescence particles which are randomly distributed on the surface of the base material, the photoluminescence array patterns which are randomly distributed can be formed, the excitation light source is a narrow-band light source, stray light can be removed, and generated light spots are not deformed and have uniqueness; if the surface of the base material is stained by fingerprints and the like, the route of light is not changed, the image of light spots is not changed, and when the technology is used for accurate positioning comparison and recognition, the positioning and recognition result is more accurate.

Description

Technical Field

[0001] The invention relates to the technical field of light spot imaging, and in particular to a high-precision photo-positioning method. Background Art

[0002] Laser is a light source with high coherence. Therefore, when two high coherence light beams collide and are within the coherence length, interference effects are likely to occur. Interference effects are divided into constructive interference and destructive interference. Constructive interference is bright, while destructive interference is dark. Therefore, interference effects are often arranged in a pattern of light and dark. Interference effects are widely used. When high coherence light is incident on a rough surface, it will be scattered due to the rough surface. The result of scattering is that many lights propagate in random directions. Therefore, when two high coherence lights collide and are within their coherence length, interference effects will occur. These high coherence scattered lights interfere with each other to form an image with many bright and dark spots. This image is a laser spot.

[0003] In the prior art, the concept of the laser spot moving with the relative motion of the light source and the illuminated surface is proposed by using the principle that the average laser spot size remains unchanged. As long as the average speed of the laser spot moving on the detector is known, the relative motion information of the light source and the illuminated surface can be inferred. This technology can then be used for precise positioning, comparison and identification of robotic arms, encoders, three-dimensional tooling, precision machine tools, etc.

[0004] Taiwan Patent TW094134281 discloses a light spot imaging device and method, which emits high coherence light through a light source. When the high coherence light irradiates a surface, scattered light is generated. The scattered light passes through a light-limiting member and generates diffraction light. The diffracted light interferes with each other to generate a light spot. The light spot is captured by a sensor to form a light spot diagram. The diffraction and interference effects are used to increase the size of the light spot, and the image of the light spot can be clear and easy to distinguish. The imaging method is very stable and sensitive. However, the above patent has the following defects: if the surface of the device is stained with fingerprints or the like in actual use, the path of the light will change, and the image of the light spot will change. When using this technology for precise positioning, comparison and recognition, errors will occur, resulting in inaccurate positioning and recognition results. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a high-precision photo-positioning method, which can solve the problem in the prior art that if there is contamination such as fingerprints on the surface of the device, the path of light will change, the image of the light spot will change, and errors will occur when using this technology for precise positioning, comparison and identification, resulting in inaccurate positioning and identification results.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a high-precision optical positioning method, the innovation of which is: comprising:

[0007] a substrate, with randomly distributed photoluminescent particles disposed on the surface of the substrate;

[0008] An excitation light source, which can evenly illuminate the surface of the substrate, so that the photoluminescent particles on the surface of the substrate are excited to generate photoluminescence, thereby generating a luminescent pattern on the surface of the substrate;

[0009] An image collector is provided with an objective lens in front of the image collector, and the objective lens is used to image the luminous pattern of a part of the surface of the substrate to the image collector, and the image collector samples the pattern and stores the image signal;

[0010] The substrate moves relative to the image collector and the excitation light source. The image collector samples at a fixed frequency. The sampling pattern before the substrate moves is recorded as the first sampling pattern, and the sampling pattern after the movement is recorded as the second sampling pattern. By comparing the first sampling pattern with the second sampling pattern, the relative movement direction and distance of the substrate can be obtained.

[0011] Preferably, the photoluminescent particles are photoluminescent mixed particles with a size of 100 nm to 5 um; the number of particles distributed per unit area is 0.01% to 20% of the pixel area.

[0012] Preferably, the photoluminescent particles are phosphor mixed particles doped with terbium rare earth, and the image collector is equipped with a 485nm bandpass filter.

[0013] Preferably, the photoluminescent particles are attached to the surface of the substrate via an adhesive, and the adhesive is a highly light-absorbing resin.

[0014] Preferably, the photoluminescent particles are randomly arranged on the surface of the substrate, and the specific preparation steps are:

[0015] S1, mixing the photoluminescent particles with an adhesive to obtain a mixture;

[0016] S2, spraying the mixture on the surface of the substrate;

[0017] S3. After the mixed agent is cured on the surface of the substrate to form a solidified layer, the upper surface of the solidified layer is polished so that the top of the photoluminescent particles is flush with the polished solidified layer.

[0018] Preferably, the photoluminescent particles are randomly arranged on the surface of the substrate, and the specific preparation steps are:

[0019] S1. Spray adhesive on the surface of substrate;

[0020] S2. Randomly distributing the photoluminescent particles on the adhesive on the surface of the substrate, so that the lower part of the photoluminescent particles is connected to the substrate through the adhesive, and the adhesive is cured to form a cured layer with exposed photoluminescent particles on the surface.

[0021] Preferably, the adhesive is black glue.

[0022] The advantages of the present invention are: by irradiating the light emitted by the excitation light source onto the randomly distributed photoluminescent particles on the surface of the substrate, a randomly distributed photoluminescent array pattern can be formed; the excitation light source is a narrow-band light source, and the emitted light has a sufficiently narrow bandwidth, which can remove stray light, and the generated light spot will not be deformed and has uniqueness;

[0023] If there are stains such as fingerprints on the surface of the substrate, the image produced by photoluminescence will basically not change. This technology can be used for precise positioning, comparison and identification, and the positioning and identification results will be more accurate. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific implementation methods. The following examples can enable technicians in this field to understand the present invention more comprehensively, but the present invention is not limited to the scope of the embodiments.

[0025] The high-precision optical positioning method of the present invention comprises:

[0026] a substrate, with randomly distributed photoluminescent particles disposed on the surface of the substrate;

[0027] An excitation light source, which can evenly illuminate the surface of the substrate, so that the photoluminescent particles on the surface of the substrate are excited to generate photoluminescence, thereby generating a luminescent pattern on the surface of the substrate;

[0028] An image collector is provided with an objective lens in front of the image collector, and the objective lens is used to image the luminous pattern of a part of the surface of the substrate to the image collector, and the image collector samples the pattern and stores the image signal;

[0029] The substrate moves relative to the image collector and the excitation light source. The image collector samples at a fixed frequency. The sampling pattern before the substrate moves is recorded as the first sampling pattern, and the sampling pattern after the movement is recorded as the second sampling pattern. By comparing the first sampling pattern with the second sampling pattern, the relative movement direction and distance of the substrate can be obtained.

[0030] More specifically, the photoluminescent particles are photomixed particles with a size of 100 nm to 5 um, and the number of particles distributed per unit area is 0.01% to 20% of the pixel area. The photoluminescent particles are attached to the surface of the substrate through an adhesive, and the adhesive is a highly light-absorbing resin.

[0031] Example 1

[0032] This embodiment adopts the following technical solution to randomly arrange the photoluminescent particles on the surface of the substrate. The specific preparation steps are:

[0033] S1. Mix photoluminescent particles with an adhesive to obtain a mixture; the photoluminescent particles are 100nm to 5um phosphor mixed particles doped with europium ions Eu3+, and the adhesive is black glue. The proportion of the photoluminescent particles in the mixture is such that the number of the phosphor mixed particles distributed per unit area is between 0.01% and 20% of the pixel area, and in most cases between 1% and 8%, and preferably 4±0.2% in this embodiment.

[0034] S2. Spray the mixture onto the surface of the substrate.

[0035] S3. After the mixed agent is cured on the surface of the substrate to form a solidified layer, the upper surface of the solidified layer is polished so that the top of the photoluminescent particles is flush with the polished solidified layer, so that the photoluminescent particles are exposed and in direct contact with the atmosphere.

[0036] When performing high-precision photolocalization, in this embodiment, the peak wavelength of the excitation light source is selected to be 393 nm, and the image collector is equipped with a 610 nm bandpass filter.

[0037] Example 2

[0038] The photoluminescent particles of this embodiment are randomly arranged on the surface of the substrate, and the specific preparation steps are:

[0039] S1. Spray adhesive on the surface of substrate;

[0040] S2. Selecting 100nm to 5um phosphor mixed particles doped with europium ions Eu3+ as photoluminescent particles, randomly spraying the photoluminescent particles on the adhesive on the surface of the substrate, so that the lower part of the photoluminescent particles is connected to the substrate through the adhesive, and the adhesive is cured to form a cured layer with exposed photoluminescent particles on the surface, and the adhesive is black glue. The number of photoluminescent particles distributed per unit area is 4±0.2% of the pixel area.

[0041] When performing high-precision photolocalization, in this embodiment, the peak wavelength of the excitation light source is selected to be 393 nm, and the image collector is equipped with a 610 nm bandpass filter.

[0042] Example 3

[0043] This embodiment adopts the following technical solution to randomly arrange the photoluminescent particles on the surface of the substrate. The specific preparation steps are:

[0044] S1. Mixing photoluminescent particles with an adhesive to obtain a mixture; the photoluminescent particles are 100nm to 5um phosphor mixed particles doped with terbium rare earth, and the adhesive is black glue. The proportion of the photoluminescent particles in the mixture is such that the number of the phosphor mixed particles distributed per unit area is 2±0.2% of the pixel area.

[0045] S2. Spray the mixture onto the surface of the substrate.

[0046] S3. After the mixed agent is cured on the surface of the substrate to form a solidified layer, the upper surface of the solidified layer is polished so that the top of the photoluminescent particles is flush with the polished solidified layer, so that the photoluminescent particles are exposed and in direct contact with the atmosphere.

[0047] When performing high-precision photolocalization, in this embodiment, the peak wavelength of the excitation light source is selected to be 377 nm, and the image collector is equipped with a 485 nm bandpass filter.

[0048] Example 4

[0049] This embodiment adopts the following technical solution to randomly arrange the photoluminescent particles on the surface of the substrate. The specific preparation steps are:

[0050] S1. Spray adhesive on the surface of substrate;

[0051] S2. Select 100nm to 5um phosphor mixed particles doped with terbium rare earth as photoluminescent particles, randomly spray the photoluminescent particles on the adhesive on the surface of the substrate, so that the lower part of the photoluminescent particles is connected to the substrate through the adhesive, and the adhesive is cured to form a cured layer with exposed photoluminescent particles on the surface, and the adhesive is black glue. The number of particles distributed per unit area of ​​the photoluminescent particles sprayed is 2±0.2% of the pixel area.

[0052] When performing high-precision photolocalization, in this embodiment, the peak wavelength of the excitation light source is selected to be 377 nm, and the image collector is equipped with a 485 nm bandpass filter.

[0053] Positioning tests were performed according to the positioning methods in Examples 1 to 4, and the test parameters and results are summarized in the following table:

[0054]

[0055]

[0056] Conclusion: Using the positioning method of the present invention, the signal-to-noise ratio of the luminous patterns obtained in Examples 1 and 2 is relatively small, and they are easily affected by the test ambient light; while the signal-to-noise ratio of Examples 3 and 4 is large, and they are not easily affected by ambient light. The distribution of pattern details collected before and after movement is almost the same, and the generated luminous patterns will not be deformed and are unique, so they can be used for accurate positioning, comparison and identification.

Claims

1. A high-precision optical positioning method, characterized in that: include a substrate, with randomly distributed photoluminescent particles disposed on the surface of the substrate; An excitation light source, which can evenly illuminate the surface of the substrate, so that the photoluminescent particles on the surface of the substrate are excited to generate photoluminescence, thereby generating a luminescent pattern on the surface of the substrate; An image collector is provided with an objective lens in front of the image collector, and the objective lens is used to image the luminous pattern of a part of the surface of the substrate to the image collector, and the image collector samples the pattern and stores the image signal; The substrate moves relative to the image collector and the excitation light source. The image collector samples at a fixed frequency. The sampling pattern before the substrate moves is recorded as the first sampling pattern, and the sampling pattern after the movement is recorded as the second sampling pattern. By comparing the first sampling pattern with the second sampling pattern, the relative movement direction and distance of the substrate can be obtained.

2. The high-precision optical positioning method according to claim 1, characterized in that: The photoluminescent particles are photoluminescent mixed particles with a size of 100 nm to 5 um; the number of particles distributed within a unit area is 0.01% to 20% of the pixel area.

3. The high-precision optical positioning method according to claim 2, characterized in that: The photoluminescent particles are fluorescent powder mixed particles doped with terbium rare earth.

4. The high-precision optical positioning method according to claim 3, characterized in that: The image collector is equipped with a 485 nm bandpass filter.

5. The high-precision optical positioning method according to claim 1, characterized in that: The photoluminescent particles are attached to the surface of the substrate via an adhesive, and the adhesive is a highly light-absorbing resin.

6. The high-precision optical positioning method according to claim 1, characterized in that: The photoluminescent particles are randomly arranged on the surface of the substrate, and the specific preparation steps are: S1, mixing the photoluminescent particles with an adhesive to obtain a mixture; S2, spraying the mixture on the surface of the substrate; S3. After the mixed agent is cured on the surface of the substrate to form a solidified layer, the upper surface of the solidified layer is polished so that the top of the photoluminescent particles is flush with the polished solidified layer.

7. The high-precision optical positioning method according to claim 1, characterized in that: The photoluminescent particles are randomly arranged on the surface of the substrate, and the specific preparation steps are: S1. Spray adhesive on the surface of substrate; S2. Randomly distributing the photoluminescent particles on the adhesive on the surface of the substrate, so that the lower part of the photoluminescent particles is connected to the substrate through the adhesive, and the adhesive is cured to form a cured layer with exposed photoluminescent particles on the surface.

8. The high-precision optical positioning method according to claim 6 or 7, characterized in that: The adhesive is black glue.

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