Multi-dimensional information loading method and structure for smart city internet of things

Abstract

This invention belongs to the field of information loading technology, and particularly relates to a multi-dimensional information loading method and structure for smart city IoT. The method includes forming at least two information loading regions on the surface of the same target emitter, respectively for loading visible light information and infrared information. Within each information loading region, the information to be loaded is encoded into optical response distribution characteristics of the corresponding dimension using at least one of spatial, spectral, angular, and surface reflectivity dimensions. By utilizing the different optical response characteristics of the information loading regions in the visible light and infrared bands, the information loading regions form independently encoded information in the visible light and infrared bands, achieving compatible loading of dual-band information. This invention enables multi-dimensional information loading on the same target emitter, thereby overcoming the limitations of traditional single information carriers in terms of information capacity and expression dimensions.

Description

Technical Field

[0001] This invention belongs to the field of information loading technology, and in particular relates to a multi-dimensional information loading method and structure for smart city Internet of Things. Background Technology

[0002] With the rapid development of smart cities, the Internet of Things, and intelligent sensing technologies, the information generated in the urban environment is characterized by a continuous increase in data volume, increasingly diverse information types, and constantly expanding information dimensions. Carriers such as road traffic signs, public facility signs, unmanned equipment navigation signs, and urban infrastructure management labels need to carry and transmit massive amounts of information. Traditional information loading and expression methods relying on a single carrier or a single information channel are insufficient to meet the integrated loading, transmission, and sensing needs of multi-source heterogeneous information.

[0003] In terms of information acquisition, the identification of visible light information is severely interfered with under low visibility conditions such as nighttime, fog, and haze, leading to discontinuous and unreliable information acquisition. Long-wave infrared bands, due to their longer wavelengths and lower atmospheric scattering and absorption losses, possess stronger penetration capabilities and superior long-distance propagation performance during atmospheric propagation. They exhibit a significant environmental adaptability advantage compared to visible light, especially in visually limited environments such as fog, smoke, and dust. Therefore, utilizing both visible and infrared bands for information transmission can effectively enhance the accuracy of information acquisition and solve the problem of limited visible information acquisition in low-visibility environments.

[0004] Furthermore, existing information loading methods typically encode information using only a single dimension, resulting in limited information loading capacity and making it difficult to achieve compatible loading and multidimensional expression of multiple types of information on the same physical carrier. How to encode information using combinations of different bands and dimensions, enabling multiple independent or related pieces of information to be compatiblely loaded and multidimensionally expressed on the same target transmitter, and selectively parsing and identifying the loaded information based on different information acquisition methods, is a pressing technical problem that needs to be solved. Summary of the Invention

[0005] In view of this, the present invention aims to provide a method and structure for loading multiple and multi-dimensional information for smart city Internet of Things, in order to solve the problems of single information loading dimension, compatible loading and multi-dimensional expression of multiple and multi-dimensional information, and limited information acquisition in low visibility environments in the prior art.

[0006] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A method for loading multi-dimensional information for smart city IoT includes the following steps: S1: At least two information loading regions are formed on the surface of the same target emitter, which are used to load visible light information and infrared information respectively; S2: In the information loading area, the information to be loaded is encoded into the optical response distribution characteristics of the corresponding dimension using at least one of the spatial dimension, spectral dimension, angular dimension and surface reflection characteristic dimension. S3: By utilizing the different optical response characteristics of the information loading area in the visible light band and the infrared band, the information loading area forms mutually independent encoded information in the visible light band and the infrared band, realizing the compatible loading of dual-band information.

[0007] Furthermore, spatial dimension information encoding includes encoding the information to be loaded using the spatial distribution characteristics of the surface of the information loading area; the information forms of spatial distribution characteristics include character-based information, graphic-based information, and encoded information; Spectral dimension information encoding includes visible light dimension encoding and infrared dimension encoding; visible light dimension encoding includes encoding the information to be loaded by utilizing the different colors or visible spectral response characteristics of the information loading region; Infrared dimension coding includes encoding the information to be loaded by controlling the infrared emissivity or infrared radiation intensity of the information loading area; Information encoding in the angular dimension includes encoding the information to be loaded using the angle-dependent optical response generated by the information loading area as it changes with its tilt angle and observation direction; The information encoding of the surface reflection characteristics dimension includes encoding the information to be loaded by using the information loading region to encode the different reflection characteristics of the incident radiation.

[0008] Furthermore, character information includes numbers, letters, and symbols; graphic information includes patterns; and encoded information includes barcodes, QR codes, and AprilTags.

[0009] Furthermore, the two information loading areas are the infrared information loading area and the visible light information loading area, respectively; The infrared emissivity or infrared radiation intensity of the infrared information loading area can be controlled using any of the following methods: The first method involves using laser processing technology to fabricate micro / nano structures on the surface of the information loading area in order to control the infrared emissivity or infrared radiation intensity. The second method involves integrating functional material layers with different infrared emissivity or infrared radiation intensity onto the surface of the information loading area.

[0010] Furthermore, when the target emitter uses a low emissivity material, a high emissivity functional material layer is integrated on the surface of the information loading area; when the target emitter uses a high emissivity material, a low emissivity functional material layer is integrated on the surface of the information loading area.

[0011] Furthermore, the functional material layer is made of metal or polymer materials, and the integration method is deposition, spraying or adhesion.

[0012] Furthermore, a polymer film covering the surface of the infrared information loading area is integrated in the visible light information loading area. The polymer film has a transmittance of >75% in the 8μm~13μm infrared band, and visible light information encoding is achieved by controlling its optical response characteristics in the visible light band.

[0013] Furthermore, by employing a passive method to utilize the naturally existing non-isothermal radiation background, spatial differences are created in the self-radiation components and reflected radiation components of different regions on the surface of the target emitter, thereby achieving infrared information loading without external energy consumption.

[0014] Furthermore, assume that the surface of the target launcher is in the observation direction. The self-radiation component on it is The calculation formula is as follows: ; in, Indicates the wavelength of infrared radiation; Indicates temperature as A blackbody at wavelength Radiance at that location; Indicates the surface temperature of the target emitter; Indicates the target emitter surface at wavelength Location, observation direction Emissivity on; and These represent the zenith angle and azimuth angle of the observation direction, respectively. Assume the surface of the target launcher is in the observation direction Above, the reflected radiation component of the background radiation is The calculation formula is as follows: ; in, Indicates background radiation at wavelength Location, equivalent blackbody temperature The radiance below; Indicates background radiation at wavelength Location, direction of incidence Emissivity on; Indicates the surface of the target launcher in the incident direction After receiving background radiation, towards the observation direction The reflection ratio coefficient; and These represent the zenith angle and azimuth angle of the incident direction, respectively. Then radiance Calculated using the following formula: .

[0015] Furthermore, depending on the ambient lighting conditions and information acquisition needs, the information loaded on the target emitter can be selectively acquired through visible light detection or infrared detection.

[0016] Furthermore, the visible light information and infrared information loaded on the surface of the target emitter can be the same information, different information, or synonymous heterogeneous information. Same information refers to information with the same semantic content and the same information expression form carried by both bands; different information refers to information with different semantic content carried by both bands; and synonymous heterogeneous information refers to information with the same semantic content carried by both bands but using different information expression forms.

[0017] A multi-dimensional information loading structure for smart city Internet of Things includes a target transmitter, on the surface of which at least two information loading areas are formed, for loading visible light information and infrared information respectively; The information loading region is configured to encode the information to be loaded into optical response distribution features in the corresponding dimension using at least one of spatial dimension, spectral dimension, angular dimension and surface reflectance characteristic dimension. The information loading area has different optical response characteristics in the visible light band and the infrared band, so as to form mutually independent encoded information in the visible light band and the infrared band, and realize the compatible loading of dual-band information.

[0018] Furthermore, the target emitter adopts a metal structure, and infrared information loading area and visible light information loading area are planned on the surface of the metal structure; Micro- and nano-structures are fabricated on the surface of the infrared information loading region using laser processing technology to achieve the control of infrared emissivity or infrared radiation intensity. A polymer film is integrated into the visible light information loading area, and a low-absorption infrared pigment is sprayed onto the surface of the polymer film to achieve color control.

[0019] Furthermore, the infrared low-absorption pigments include any one or any combination of two or more of the following: red pigments, yellow pigments, blue pigments, and white pigments; the red pigments are iron oxide particles; the yellow pigments are goethite particles or silicon particles; the blue pigments are Prussian blue particles; and the white pigments are zinc oxide particles.

[0020] Compared with the prior art, the present invention can achieve the following beneficial effects: First, this invention encodes information using at least one of the following dimensions: spatial dimension, spectral dimension, angular dimension, and surface reflectivity dimension. The spatial dimension can load information through spatial distribution such as numbers, characters, QR codes, and patterns; the spectral dimension can load information through color in the visible band and through infrared emissivity or infrared radiation intensity in the infrared band; the angular dimension can load information using the changes in infrared radiation intensity caused by the target emitter's tilt angle and observation direction; and the surface reflectivity dimension can load information by adjusting the ratio of specular reflectivity to diffuse reflectivity. Through combinations of different bands and dimensions, multiple types of information can be compositely loaded and multidimensionally expressed on the same target emitter, enabling a limited physical carrier to carry more information.

[0021] Second, this invention loads information in both the visible light and infrared bands. The visible light band meets the visual recognition needs of the human eye, while the infrared band utilizes the strong penetrating power of long-wave infrared light through atmospheric windows, ensuring reliable information transmission even in low-visibility conditions such as nighttime, fog, and haze. The same information can be loaded in both bands to achieve continuous information transmission during the day and night; alternatively, synonymous but heterogeneous information can be loaded in both bands. For example, the visible band can use graphics or text that conform to human visual recognition habits, while the infrared band can use machine-readable coded patterns, thus simultaneously meeting the visual recognition needs of the human eye and the machine recognition needs of autonomous driving systems and machine vision systems.

[0022] Third, this invention utilizes the differences in infrared radiation characteristics between different regions on the surface of the target emitter to construct spatially distributed differences in radiance against a non-isothermal radiation background, achieving passive infrared information transmission without the need for external power supply. This method overcomes the limitation of traditional infrared communication relying on active radiation sources, fundamentally reducing system energy consumption and structural complexity.

[0023] Fourth, this invention achieves infrared information encoding by laser processing of a metal structure, which can be made of aluminum, copper, or aluminum alloy. Visible information is encoded using infrared low-absorption pigment particles, such as iron oxide, goethite, Prussian blue, and zinc oxide particles. The raw materials are readily available, the process is simple, and large-area processing can be achieved.

[0024] Fifth, the multi-dimensional information loading structure provided by this invention can be set on carriers such as road traffic signs, license plates, public facility signs, unmanned equipment navigation signs, or urban infrastructure management labels. It uses the visible light band to meet the visual recognition needs of the human eye and the infrared band to meet the recognition needs of intelligent devices under nighttime and low visibility conditions, realizing compatible loading of dual-band information and all-weather information transmission, providing a new technical approach for smart cities, the Internet of Things, intelligent sensing, and information interaction scenarios. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A flowchart illustrating the multi-dimensional information loading method for smart city IoT as described in an embodiment of the present invention; Figure 2 A schematic diagram showing the difference in radiance of different radiation characteristic regions on the surface of the target emitter under different tilt angles and different observation angles, as described in the embodiments of the present invention. Figure 3 A schematic diagram illustrating the difference in radiance across different radiation characteristic regions on the surface of a target emitter under varying specular and diffuse reflectance ratios, as described in an embodiment of the present invention. Figure 4 A schematic diagram of star patterns with different infrared radiation characteristics as described in the embodiments of the present invention; Figure 5 An infrared photographic illustration of star patterns with different infrared radiation characteristics under outdoor conditions, as described in the embodiments of the present invention; Figure 5 This indicates that, under non-isothermal radiation background, there are significant differences in radiance among emitters with different infrared radiation characteristics; Figure 6 This is a schematic diagram of an infrared photograph of a target emitter under a non-isothermal radiation background, as described in an embodiment of the present invention. Figure 7 This is a schematic diagram of an infrared photograph of a target emitter under isothermal radiation background, as described in an embodiment of the present invention. Figure 8 An infrared photograph of the aluminum plate coded with AprilTag as described in Embodiment 1 of the present invention; Figure 9 This is a schematic diagram of infrared images of AprilTag captured by a vehicle under different steering commands as described in Embodiment 1 of the present invention; wherein the steering commands executed by the vehicle include left turn command, straight-ahead command, and right turn command; Figure 10 A visible light photographic illustration of the polymer film integrated on the surface of the aluminum plate as described in Embodiment 1 of this invention; Figure 11 A schematic diagram of the test platform for assisting safe nighttime driving based on traffic signs, as described in Embodiment 2 of the present invention, and the test results thereof; Figure 12 An infrared photographic illustration of an aluminum plate with a QR code coded on it, as described in Embodiment 3 of this invention; Figure 13A schematic diagram of the test platform for assisting autonomous driving in foggy weather constructed according to Embodiment 3 of the present invention and the test results under fog-free conditions; Figure 14 A schematic diagram of the test platform for assisting autonomous driving in foggy weather, as described in Embodiment 3 of the present invention, and the test results under foggy conditions; Figure 15 A visible light photograph schematic diagram of the polymer film integrated on the surface of the aluminum plate as described in Embodiment 3 of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] This invention provides a multi-dimensional information loading method for smart city IoT. "Multi-dimensional" means that the target emitter can load information in multiple different bands, including visible band information, infrared band information, and joint information of visible and infrared bands, thereby realizing independent loading, combined loading, or collaborative loading of information in different bands. "Multi-dimensional" means that the target emitter can use multiple different physical dimensions to encode and load information, including spatial dimension, spectral dimension, angular dimension, and surface reflectivity dimension.

[0032] like Figure 1 As shown, this multi-dimensional information loading method for smart city IoT includes the following steps: S1: At least two information loading regions are formed on the surface of the same target emitter, which are used to load visible light information and infrared information respectively.

[0033] The information loading areas are divided into infrared information loading areas and visible light information loading areas according to the type of information loaded. The infrared information loading areas are used to load infrared information, and the visible light information loading areas are used to load visible light information. There is at least one infrared information loading area and one visible light information loading area. These two types of information loading areas can be distributed at different locations on the target emitter's surface, or they can be distributed at the same location on the target emitter's surface. When the infrared and visible light information loading areas are distributed at the same location on the target emitter's surface, they spatially overlap, and the visible light information loading area covers the outer side of the infrared information loading area. Specifically, a polymer film covering the surface of the infrared information loading area is integrated into the visible light information loading area. This polymer film has a transmittance >75% in the 8μm~13μm infrared band, and by controlling its optical response characteristics in the visible light band, visible light information encoding is achieved, ensuring that the loaded visible light information and infrared information do not interfere with each other. The polymer film can be a nanoporous polyethylene film. The visible light band information encoding is achieved based on low-absorption pigment particles in the infrared band, a mask, and a spraying process.

[0034] S2: In the information loading region, the information to be loaded is encoded into optical response distribution features in the corresponding dimension by utilizing at least one of the spatial dimension, spectral dimension, angular dimension and surface reflection characteristic dimension.

[0035] For visible light information loading regions, information can be encoded using spatial and spectral dimensions. For infrared information loading regions, information can be encoded using spatial, spectral, angular, and surface reflectivity dimensions.

[0036] Spatial information encoding includes encoding the visible light information to be loaded using the spatial distribution characteristics of the surface of the area loaded with visible light information; it also includes encoding the infrared information to be loaded using the spatial distribution characteristics of the surface of the area loaded with infrared information. The information forms of spatial distribution characteristics include character-based information, graphic-based information, and coded information. Character-based information includes, but is not limited to, numbers, letters, and symbols. Graphic-based information includes, but is not limited to, patterns. Coded information includes, but is not limited to, barcodes, QR codes, and AprilTags.

[0037] The optical response distribution characteristics encoded with visible light information can be recognized by the human eye or visible light detection devices. However, the optical response distribution characteristics encoded with infrared information can only be recognized by infrared detection devices.

[0038] Spectral dimension information encoding includes visible light dimension encoding and infrared dimension encoding. Visible light dimension encoding involves encoding the visible light information to be loaded using different colors or visible spectral response characteristics of the information loading region. Infrared dimension encoding involves encoding the information to be loaded using the modulation of infrared emissivity or infrared radiation intensity of the information loading region.

[0039] The infrared emissivity or infrared radiation intensity of the infrared information loading area can be controlled using any of the following methods: The first method involves using laser processing technology to fabricate micro / nano structures on the surface of the information loading area in order to control the infrared emissivity or infrared radiation intensity. The second method involves integrating functional material layers with different infrared emissivity or infrared radiation intensity onto the surface of the information loading area using methods such as deposition, spraying, transfer, or adhesion, thereby forming a radiation characteristic distribution with spatial differences.

[0040] Figure 4 The image shows star patterns with different emissivity constructed on the surface of a low-emissivity target emitter using femtosecond laser processing technology. The emissivity of the star patterns are as follows: ε ≈0.03、 ε ≈0.5 and ε ≈0.9. Figure 5The image shows infrared images of star patterns with different emissivity under outdoor conditions. The star patterns with different emissivity exhibit significant differences in radiance, indicating that the information to be encoded can be modulated through infrared radiation characteristics. It is noteworthy that the selection of the target emitter is not affected by emissivity. When a low-emissivity (ε≈0.03) target emitter is selected, a high-emissivity functional material layer is integrated into a predetermined area on the target emitter's surface. When a high-emissivity (ε≈0.9) target emitter is selected, a low-emissivity functional material layer is integrated into a predetermined area on the target emitter's surface. The functional material layer includes, but is not limited to, metallic materials, ceramic materials, polymer materials, oxide materials, and composite functional materials.

[0041] The target emitter is selected as a broadband emitter, which has an emissivity of nearly 1 in the 4μm–20μm band and nearly 0 in other bands. Preferably, the target emitter is a spectrally selective emitter with an emissivity of nearly 1 in the 8μm–13μm band and nearly 0 in other bands. Both broadband and spectrally selective emitters possess effective radiance differences, enabling stable infrared information transmission.

[0042] The information encoding in the angular dimension involves encoding the information to be loaded using the angle-dependent optical response generated by the infrared information loading area as it changes with its tilt angle and observation direction. For example... Figure 2 As shown, for the target emitter, its infrared radiance (in Wm) -2 sr -1 The intensity of infrared information changes with its own tilt angle and the observation angle. Different tilt angles and observation angles can obtain different infrared information intensities. Therefore, the observation angle can be used as the information loading dimension to realize information encoding, transmission and recognition based on the observation direction.

[0043] The information encoding of the surface reflectivity dimension involves encoding the information to be loaded using the different reflectivity of the incident radiation in the infrared information loading region. By adjusting the ratio of specular reflectivity to diffuse reflectivity of the surface of the infrared information loading region, the infrared information loading region exhibits different optical responses under corresponding detection conditions, thereby forming different information loading channels.

[0044] like Figure 3 As shown, the radiance (in Wm) of different radiation characteristic regions on the surface of the target emitter is displayed under different specular reflectance and diffuse reflectance ratios. -2 sr -1 Differences. At different specular reflectivities... r s and diffuse reflectance r dUnder the given ratio, the difference in radiance between target emitters with different emissivity is different. Therefore, the ratio of specular reflectivity to diffuse reflectivity on the surface of the target emitter can be used as the information loading dimension.

[0045] Optical response distribution characteristics refer to the features formed by the distribution of optical response parameters of a target emitter's surface according to specific laws in terms of spatial position, wavelength, observation angle, or surface reflectivity within a specific wavelength band. Optical response parameters include color, reflectivity, and pattern in the visible light band; emissivity, radiance, and radiant intensity in the infrared band; and radiant intensity varying with the observation angle. Optical response distribution characteristics are formed by the manipulation of at least one of the spatial, spectral, angular, and surface reflectivity dimensions, and can be acquired and interpreted by corresponding optical detection devices as loaded information. For example, in the visible light band, it manifests as a color distribution or pattern distribution; in the infrared band, it manifests as an infrared emissivity distribution or radiance distribution.

[0046] S3: By utilizing the different optical response characteristics of the information loading area in the visible light band and the infrared band, the information loading area forms mutually independent encoded information in the visible light band and the infrared band, realizing the compatible loading of dual-band information.

[0047] By combining different bands and dimensions, the present invention can achieve compatible loading of multiple types of information on the same target emitter, and use one or more of the following factors: band, spatial dimension, spectral response, sample tilt angle and detector observation angle, and surface reflection characteristics to distinguish, transmit and identify the loaded information, thereby improving the information loading capacity and information expression dimension.

[0048] The visible light information and infrared information loaded on the surface of the target emitter can be the same information, different information, or synonymous heterogeneous information. Same information means that the visible light band and the infrared band carry information with the same semantic content and use the same information expression form. Different information means that the visible light band and the infrared band carry information with different semantic content. Synonymous heterogeneous information means that the visible light band and the infrared band carry information with the same semantic content but use different information expression forms.

[0049] This invention utilizes a passive method to leverage naturally occurring non-isothermal radiation backgrounds, creating spatial differences between the intrinsic radiation component and the reflected radiation component of the target emitter surface, thus achieving infrared information transmission without external energy consumption. Specifically, the encoded target emitter surface is placed in a non-isothermal radiation background. By utilizing the differences in emissivity and reflectivity of different regions on the target emitter surface, spatial differences are created between the intrinsic radiation component and the reflected radiation component of each region, thereby generating a radiation brightness contrast pattern on the target emitter surface that can be recognized by infrared detection equipment.

[0050] Non-isothermal radiation background includes, but is not limited to, sky radiation background and ground radiation background. Sky radiation background refers to the radiation field from the sky, acting as a low-temperature radiation source incident on the surface of the target emitter. When a certain area on the surface of the target emitter has low emissivity, this low-emissivity area reflects the low-temperature radiation from the sky into the infrared detection equipment. Ground radiation background refers to the radiation field from the Earth's surface and near-surface objects, acting as a high-temperature radiation source incident on the surface of the target emitter. When a certain area on the surface of the target emitter has low emissivity, it reflects the high-temperature radiation from the ground into the infrared detection equipment.

[0051] Total radiance produced on the surface of the target emitter Calculate according to the following formula: ; in, Indicates the surface of the target launcher in the observation direction The self-radiation component on; Indicates the surface of the target launcher in the observation direction Above, the radiance reflected from the background radiation; and The zenith angle and azimuth angle represent the direction of observation, respectively; the direction of observation. This refers to the direction in which an infrared detection device looks at the surface of a target emitter.

[0052] Self-radiation component of the target emitter surface The calculation depends on the target emitter's own temperature and emissivity, and is performed according to the following formula: ; in, Indicates the wavelength of infrared radiation; Indicates temperature as A blackbody at wavelength Radiance at that location Indicates the surface temperature of the target emitter; Indicates the target emitter surface at wavelength Location, observation direction Emission rate.

[0053] Reflected radiation component of background radiation from the surface of the target emitter The calculation is based on the reflectivity of the target emitter's surface and the background radiation, using the following formula: ; in, Indicates background radiation at wavelength Location, equivalent blackbody temperature The radiance below; Indicates background radiation at wavelength Location, direction of incidence Emissivity on; Indicates the surface of the target launcher in the incident direction After receiving background radiation, towards the observation direction The reflection ratio coefficient; and These represent the zenith angle and azimuth angle of the incident direction, respectively; the incident direction refers to the direction in which background radiation (such as infrared radiation emitted from the sky or the ground) shines on the surface of the target emitter.

[0054] This invention uses specular reflective emitters and diffuse reflective emitters as information carriers, respectively, and analyzes the physical mechanism by which they achieve information encoding and transmission under non-isothermal radiation background.

[0055] For an ideal specular reflector, its reflected radiation component exhibits significant directional selectivity, and the formula for the reflected radiation component described above can be simplified to: ; in, This indicates the specular reflectivity.

[0056] For an ideal diffuse reflector, its reflected radiation components are averaged over the angular channel, and these components can be expressed as: ; ; in, r d Indicates diffuse reflectance. The average emissivity of the hemisphere is calculated by integrating the directional emissivity within the upper hemisphere. The reflected radiation components can then be expressed as: .

[0057] The passive infrared information transmission method proposed in this invention is based on the following core principle: the total radiance of a target emitter surface consists of two parts: its own radiative component and the background reflected radiative component. Emissivity and reflectivity satisfy a complementary relationship under the law of energy conservation (high emissivity means low reflectivity, and vice versa). When the encoded surface is placed in a non-isothermal radiation background, the intensity of ambient infrared radiation incident from different directions varies. Since the emissivity (and complementary reflectivity) of each region on the surface has been spatially encoded, the contribution of each region to its own radiative component and the background reflected radiative component differs: high emissivity regions are dominated by their own radiative component (large contribution) and supplemented by the background reflected radiative component (small contribution), resulting in higher total radiance; low emissivity regions are the opposite, with weaker own radiative component and stronger background reflected radiative component, resulting in lower total radiance. Based on this physical mechanism, the target emitter surface generates spatial differences in radiance under a non-isothermal radiation background, thereby forming a radiance contrast pattern recognizable by infrared detection equipment without external power supply, achieving passive transmission of infrared information.

[0058] It should be noted that, from the perspective of infrared radiation mechanisms, any object with a temperature above absolute zero can radiate energy outwards. Outer space, with a temperature of 3K, is considered a cryogenic radiation background and has received widespread attention. We utilize the reflectivity of the target emitter to couple the 3K outer space temperature to the 300K surface of the target emitter. Due to the significant difference between the target emitter's own radiation component and the reflected radiation component, the surface regions of the target emitter with different radiation characteristics will form a contrast in radiance that can be identified by infrared detection equipment, thereby enabling the encoding and transmission of infrared information. Clearly, the non-isothermal radiation background formed by the 3K outer space temperature and the environment in which the target emitter is located is a necessary condition for the generation of radiance differences. Figure 6 As shown, when the target emitter is placed against a non-isothermal radiation background, a difference in radiance is generated on the surface of the target emitter, enabling the loading and transmission of infrared information. The radiance comparison pattern is a QR code and can be identified. If the target emitter is placed against an isothermal radiation background, no difference in radiance is generated on the surface of the target emitter, and the loading and transmission of infrared information cannot be achieved. Figure 7 As shown, the QR code cannot be recognized.

[0059] This invention also provides a multi-dimensional information loading structure for smart city IoT, including a target emitter. Preferably, the target emitter is made of metal, such as aluminum, copper, or aluminum alloy. At least one visible light information loading area and at least one infrared information loading area are planned on the surface of the target emitter for loading visible light information and infrared information loading, respectively.

[0060] Micro- and nano-structures are fabricated on the surface of the infrared information loading area using laser processing technology to achieve the control of infrared emissivity or infrared radiation intensity, thereby enabling the encoding and transmission of infrared information.

[0061] A polymer film is integrated into the visible light information loading area, and infrared low-absorption pigments are sprayed onto the surface of the polymer film, or infrared low-absorption pigments are directly sprayed onto the surface of the target emitter to achieve color control.

[0062] Low-absorption pigments in the infrared band include any one or any combination of two or more of red, yellow, blue, and white pigments; the red pigment is iron oxide particles; the yellow pigment is goethite or silicon particles; the blue pigment is Prussian blue particles; and the white pigment is zinc oxide particles. Any color can be obtained by mixing multiple pigments in different proportions. For example, mixing prepared yellow and blue pigments in a 1:1 ratio yields green pigment; mixing prepared yellow and red pigments in a 1:1 ratio yields orange pigment. Besides using zinc oxide particles, dispersants can also be used as white pigments without adding any other pigments.

[0063] The specific spraying process used in this invention is as follows: Step 1: Mix the pigments and dispersant in the specified proportions and stir at a speed of not less than 300 rpm for at least 3 hours at room temperature.

[0064] The mass ratio of each pigment to the dispersant is 1g:100g to 1.5g:100g.

[0065] The dispersant consists of a dispersion solution and a binder. The dispersion solution is tetrahydrofuran, and the binder is the polymer SEBS; alternatively, the dispersion solution is dichloromethane, and the binder is nitrile rubber and hexamethylene diisocyanate. The mass ratio of the binder to the dispersion solution is 1g:10g to 1g:20g.

[0066] Step 2: Pour the mixed pigments and dispersant into the spray gun and spray.

[0067] The spray gun nozzle diameter is between 0.5cm and 1.5cm, and the spraying air pressure is between 2Bar and 3Bar.

[0068] This invention can be combined with a mask template to spatially control the color of the visible light information loading area.

[0069] Example 1: Vehicle steering intention prediction based on AprilTag This embodiment 1 provides an application of a passive infrared information transmission method in vehicle steering intention prediction, realizing passive infrared transmission of vehicle steering intention for early warning of vehicles behind.

[0070] Using low emissivity ( ε Using an aluminum plate with an emissivity of approximately 0.03 g / m² as the substrate material (i.e., the target emitter), and employing femtosecond laser surface processing technology, the emissivity of a localized area of ​​the aluminum plate is modulated to achieve a spatially programmable distribution of emissivity in different regions. This allows for the creation of an AprilTag on the aluminum plate surface for vehicle steering prediction, as shown in the infrared image. Figure 8 As shown.

[0071] like Figure 9 As shown, in an outdoor experimental environment, an aluminum plate with an AprilTag coded on its surface was installed at a predetermined position at the rear of a vehicle, and the vehicle was controlled to execute straight-ahead, left-turn, and right-turn commands respectively. During vehicle movement, an infrared thermal imager was used to image the AprilTag at the rear of the vehicle to obtain infrared photos corresponding to different motion states. Based on the infrared photos, a vision processing system was used to analyze the AprilTag and extract the vehicle's attitude information under different motion states, thereby realizing the vehicle's yaw angle. α Calculation and representation.

[0072] Specifically, the vision processing system first detects the two-dimensional pixel coordinates of the four corner points of the AprilTag in the image coordinate system; then, combining the actual physical size parameters of the AprilTag and the intrinsic parameters of the infrared imaging device, it uses the PnP pose solving algorithm to calculate the three-dimensional spatial pose of the AprilTag in the camera coordinate system; finally, it performs Euler angle decomposition on the rotation matrix corresponding to the pose to obtain the vehicle's yaw angle information. α When =0, it corresponds to vehicles going straight; when α When >0, it corresponds to a vehicle turning left; when α When the yaw angle is less than 0, it corresponds to a right turn. Therefore, by determining the yaw angle, the vehicle's lane-changing intention can be predicted.

[0073] Specifically, to ensure the vehicle's aesthetics, a polymer film with high infrared transmittance and information encoding capabilities in the visible band is further integrated onto the surface of the aluminum plate coded with the AprilTag. Its visible image is shown in the image below. Figure 10 As shown.

[0074] Example 2: Traffic Sign-Based Nighttime Safe Driving Assistance This embodiment 2 provides an application of a passive infrared information transmission method in nighttime safe driving assistance, which uses traffic signs to provide route guidance for vehicles driving at night.

[0075] Using low emissivity ( ε Using aluminum foil with an emissivity of approximately 0.03 as the base material, and through a high emissivity coating ( ε (≈0.9) Spatially regulate the emissivity of the aluminum foil surface to construct a series of traffic signs on the aluminum foil surface.

[0076] like Figure 11 As shown, a test platform for assisting safe nighttime driving was built based on traffic signs in an outdoor experimental environment. The test platform includes a remote-controlled vehicle equipped with both a visible camera and an infrared camera, with traffic signs placed along one side of the vehicle's preset driving trajectory. During the test, the remote-controlled vehicle traveled along the preset path, and the visible and infrared cameras monitored and collected data on the traffic signs within its field of view in real time. Figure 11 The test results shown in the inset indicate that, under low visibility conditions at night, visible light cameras can hardly identify traffic signs, while infrared cameras can clearly identify them, thus verifying the auxiliary role of traffic signs in safe driving at night.

[0077] In particular, to ensure the universality of traffic signs in both the visible and infrared bands, a polymer film with high transmittance in the infrared band and information encoding capability in the visible band is further integrated onto the surface of the aluminum foil on which the traffic signs are encoded. The traffic sign pattern visible under visible light is then created on the polymer film using infrared transparent pigments (such as nanoparticles like titanium dioxide), enabling the traffic signs to be recognized by visible light cameras during the day and achieving day and night universality.

[0078] The essence of achieving day and night usability is to display traffic signs using visible light during the day and infrared light at night or in environments with limited visible light. By loading the same information into different bands, traffic signs can achieve continuous information transmission from day to night, thereby improving the all-weather adaptability of information transmission.

[0079] Example 3: QR Code-Based Assisted Autonomous Driving in Fog This embodiment 3 provides an application of a passive infrared information transmission method in autonomous driving in foggy weather, using QR code traffic signs to provide steering instructions for unmanned vehicles.

[0080] Using low emissivity ( ε Aluminum plates with an emissivity of ≈0.03 g / m² were used as the base material, and a high emissivity coating was applied. ε ≈0.9) Spatial emissivity modulation is applied to the surface of an aluminum plate to construct a QR code for storing vehicle steering commands. Its infrared image is shown below. Figure 12 As shown.

[0081] like Figure 13 and Figure 14As shown, a test platform for assisting autonomous driving in foggy weather was built in an outdoor experimental environment. The test platform includes a smart car equipped with both visible and infrared cameras, and a fog chamber to simulate foggy conditions. An aluminum plate encoded with a QR code serves as a traffic sign inside the fog chamber, positioned on one side of the smart car's preset driving trajectory to provide instruction information.

[0082] Specifically, the intelligent vehicle integrates an OpenMV-based visual recognition system and an Arduino feedback control module, enabling it to autonomously acquire instruction information from traffic signs and execute corresponding movement decisions. The fog box is sealed with an infrared-transparent polyethylene film and generates a stable fog environment using standard atomization equipment. During testing, the intelligent vehicle travels along a preset path and reads the instruction information carried by traffic signs in real time as it approaches them; based on this instruction information, the intelligent vehicle makes autonomous driving decisions at intersections.

[0083] The test was conducted under both fog-free and foggy conditions. Figure 13 and Figure 14 The illustration in the upper part of the image shows the test results under two conditions. Under fog-free conditions, the visible photo clearly shows the pattern with the right-turn arrow, and the infrared photo clearly shows the coded QR code pattern. This indicates that under fog-free conditions, both visible light and infrared bands can be recognized normally. However, under fog conditions, the right-turn arrow in the visible photo is significantly attenuated or even unrecognizable due to the scattering effect of the fog, but the QR code in the infrared photo remains clear and recognizable. This indicates that under fog conditions, the visible light band fails, while the infrared band can be recognized normally. In other words, in foggy conditions, the information transmission reliability of the infrared band is significantly better than that of the visible light band, thus effectively assisting autonomous driving in foggy weather.

[0084] Specifically, similar to Example 2, to ensure the versatility of the traffic sign in both the visible and infrared bands, a polymer film with high transmittance (transmittance > 75%) in the infrared band and information encoding capability in the visible band is further integrated onto the surface of the aluminum plate encoded with infrared information. This allows the traffic sign to maintain its infrared information detection capability while also possessing the visual recognition function of a traditional visible light traffic sign, such as... Figure 15 As shown.

[0085] The visible band is primarily used to provide traffic guidance information to drivers. Therefore, it employs graphic forms such as turn arrows, consistent with traditional traffic sign expression habits, for intuitive driver recognition. The infrared band is mainly used to provide traffic instruction information to autonomous vehicles or other machine vision systems. Therefore, it uses QR codes, coded patterns, or other machine-readable forms for information loading, enabling machine vision systems to recognize and interpret it. By using information expression forms adapted to different information acquisition targets in different bands, the same traffic sign can simultaneously meet the visual recognition needs of drivers and the machine recognition needs of autonomous driving systems. Furthermore, by utilizing the detection characteristics of the visible and infrared bands under different environmental conditions, the continuity, reliability, and environmental adaptability of information transmission under complex weather conditions are improved.

[0086] Example 4: Cooperative Communication of Unmanned Aerial Vehicle Swarm Based on Flexible Encoded Identifiers This embodiment 4 provides an application of a passive infrared information transmission method in collaborative communication of UAV swarms, which utilizes flexible and lightweight coded identifiers to achieve passive identification and relative positioning between UAVs.

[0087] High emissivity ( ε Polyimide with an emissivity of approximately 0.9 g / L was used as a flexible substrate material, and a low emissivity coating was applied. ε Spatially modulate the emissivity of the polyimide surface (≈0.03) to construct an information coding structure for identification and positioning on the polyimide surface. This coding structure can be further used in UAV swarm collaborative communication scenarios for individual UAV identification, relative position calibration, and formation status information transmission.

[0088] Specifically, each UAV can be equipped with a flexible coded tag based on emissivity modulation. An onboard infrared detector identifies the coded information on the surface of neighboring UAVs, thereby obtaining the corresponding UAV's identity and spatial location information. Based on this information, coordinated control and formation maintenance within the cluster are achieved. In this embodiment 4, the reading of the coded information relies on an infrared imaging device to identify the differences in radiance formed by different emissivity regions, thus achieving passive information transmission and interaction without the need for additional power.

[0089] In particular, to improve concealment, a polymer film with high transmittance in the infrared band and information encoding capability in the visible band is further integrated on the surface of the polyimide used for encoding information, in order to achieve camouflage in the visible band.

[0090] Compared with the prior art, the present invention can achieve the following beneficial effects: First, it enables multi-dimensional information loading, improving information loading capacity and expression dimensions.

[0091] This invention encodes information using at least one of the following dimensions: spatial dimension, spectral dimension, angular dimension, and surface reflectivity dimension. The spatial dimension can load information through spatial distribution such as numbers, characters, QR codes, and patterns; the spectral dimension can load information through color in the visible band and through infrared emissivity or infrared radiation intensity in the infrared band; the angular dimension can load information using the changes in infrared radiation intensity caused by the target emitter's tilt angle and observation direction; and the surface reflectivity dimension can load information by adjusting the ratio of specular reflectivity to diffuse reflectivity. By combining different bands and dimensions, multiple types of information can be compositely loaded and multidimensionally expressed on the same target emitter, enabling a limited physical carrier to carry more information.

[0092] Second, it enables all-weather information transmission and identification, improving the reliability of information acquisition in low-visibility environments.

[0093] This invention loads information in both the visible light and infrared bands. The visible light band meets the visual recognition needs of the human eye, while the infrared band utilizes the strong penetrating power of long-wave infrared light through atmospheric windows, ensuring reliable information transmission even in low-visibility conditions such as nighttime, fog, and haze. The same information can be loaded in both bands to achieve continuous information transmission during the day and night; alternatively, synonymous but heterogeneous information can be loaded in both bands. For example, the visible light band can use graphics or text that conform to human visual recognition habits, while the infrared band can use machine-readable coded patterns, thus simultaneously satisfying both the visual recognition needs of the human eye and the machine recognition needs of autonomous driving systems and machine vision systems.

[0094] Third, it enables information transmission without the need for external energy consumption.

[0095] This invention utilizes the differences in infrared radiation characteristics between different regions on the surface of a target emitter to construct spatially distributed differences in radiance within a naturally occurring non-isothermal radiation background, achieving passive infrared information transmission without the need for external power supply. This method overcomes the limitation of traditional infrared communication relying on active radiation sources, fundamentally reducing system energy consumption and structural complexity.

[0096] Fourth, the preparation process is simple, it can be processed on a large scale, and it has strong environmental adaptability.

[0097] This invention achieves infrared information encoding by laser processing of metal structures. The metal structure can be made of aluminum, copper, or aluminum alloy, and the pigment can be made of iron oxide, goethite, Prussian blue, zinc oxide, or other particles. The raw materials are readily available, the process is simple, and large-area processing can be achieved.

[0098] Fifth, it can be widely used as an information carrier for the Internet of Things in smart cities.

[0099] The multi-dimensional information loading structure provided by this invention can be set on carriers such as road traffic signs, license plates, public facility signs, unmanned equipment navigation signs, or urban infrastructure management labels. It uses the visible light band to meet the visual recognition needs of the human eye and the infrared band to meet the recognition needs of intelligent devices under nighttime and low visibility conditions, realizing compatible loading of dual-band information and all-weather information transmission, providing a new technical approach for smart cities, the Internet of Things, intelligent sensing, and information interaction scenarios.

[0100] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0101] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for loading multi-dimensional information for smart city Internet of Things, characterized in that, Includes the following steps: S1: At least two information loading regions are formed on the surface of the same target emitter, which are used to load visible light information and infrared information respectively; S2: In the information loading area, the information to be loaded is encoded into the optical response distribution characteristics of the corresponding dimension using at least one of the spatial dimension, spectral dimension, angular dimension and surface reflection characteristic dimension. S3: By utilizing the different optical response characteristics of the information loading area in the visible light band and the infrared band, the information loading area forms mutually independent encoded information in the visible light band and the infrared band, realizing the compatible loading of dual-band information.

2. The multi-dimensional information loading method for smart city IoT according to claim 1, characterized in that, Information encoding in the spatial dimension includes encoding the information to be loaded using the spatial distribution characteristics of the surface of the information loading area; the information forms of spatial distribution characteristics include character-based information, graphic information, and encoded information; Spectral dimension information encoding includes visible light dimension encoding and infrared dimension encoding; visible light dimension encoding includes encoding the information to be loaded by utilizing the different colors or visible spectral response characteristics of the information loading region; Infrared dimension coding includes encoding the information to be loaded by controlling the infrared emissivity or infrared radiation intensity of the information loading area; Information encoding in the angular dimension includes encoding the information to be loaded using the angle-dependent optical response generated by the information loading area as it changes with its tilt angle and observation direction; The information encoding of the surface reflection characteristics dimension includes encoding the information to be loaded by using the information loading region to encode the different reflection characteristics of the incident radiation.

3. The multi-dimensional information loading method for smart city IoT according to claim 2, characterized in that, Character information includes numbers, letters, and symbols; graphic information includes patterns; and encoded information includes barcodes, QR codes, and AprilTags.

4. The multi-dimensional information loading method for smart city IoT according to claim 2, characterized in that, The two information loading areas are the infrared information loading area and the visible light information loading area, respectively. The infrared emissivity or infrared radiation intensity of the infrared information loading area can be controlled using any of the following methods: The first method involves using laser processing technology to fabricate micro / nano structures on the surface of the information loading area in order to control the infrared emissivity or infrared radiation intensity. The second method involves integrating functional material layers with different infrared emissivity or infrared radiation intensity onto the surface of the information loading area.

5. The multi-dimensional information loading method for smart city IoT according to claim 4, characterized in that, When the target emitter uses a low emissivity material, a high emissivity functional material layer is integrated on the surface of the information loading area; when the target emitter uses a high emissivity material, a low emissivity functional material layer is integrated on the surface of the information loading area.

6. The multi-dimensional information loading method for smart city IoT according to claim 4 or 5, characterized in that, The functional material layer is made of metal or polymer materials, and the integration method is deposition, spraying or adhesion.

7. The multi-dimensional information loading method for smart city IoT according to claim 4, characterized in that, A polymer film covering the surface of the infrared information loading area is integrated in the visible light information loading area. The polymer film has a transmittance of >75% in the 8μm~13μm infrared band, and visible light information encoding is achieved by controlling its optical response characteristics in the visible light band.

8. The multi-dimensional information loading method for smart city IoT according to claim 1, characterized in that, By employing a passive method and utilizing the naturally existing non-isothermal radiation background, spatial differences are created in the self-radiation components and reflected radiation components of different regions on the surface of the target emitter, thereby achieving infrared information loading without external energy consumption.

9. The multi-dimensional information loading method for smart city IoT according to claim 8, characterized in that, Assume the surface of the target launcher is in the observation direction The self-radiation component on it is The calculation formula is as follows: ； in, Indicates the wavelength of infrared radiation; Indicates temperature as A blackbody at wavelength Radiance at that location; Indicates the surface temperature of the target emitter; Indicates the target emitter surface at wavelength Location, observation direction Emissivity on; and These represent the zenith angle and azimuth angle of the observation direction, respectively. Assume the surface of the target launcher is in the observation direction Above, the reflected radiation component of the background radiation is The calculation formula is as follows: ； in, Indicates background radiation at wavelength equivalent blackbody temperature The radiance below; Indicates background radiation at wavelength Location, direction of incidence Emissivity on; Indicates the surface of the target projectile in the incident direction After receiving background radiation, towards the observation direction The reflection ratio coefficient; and These represent the zenith angle and azimuth angle of the incident direction, respectively; Then radiance Calculated using the following formula: 。 10. The multi-dimensional information loading method for smart city IoT according to claim 1, characterized in that, Depending on the ambient lighting conditions and information acquisition needs, the information loaded on the target emitter can be selectively acquired through visible light detection or infrared detection.

11. The multi-dimensional information loading method for smart city IoT according to claim 1, characterized in that, The visible light information and infrared information loaded on the surface of the target emitter can be the same information, different information, or synonymous heterogeneous information. Same information refers to information with the same semantic content and the same information expression form carried by both bands; different information refers to information with different semantic content carried by both bands; and synonymous heterogeneous information refers to information with the same semantic content carried by both bands but with different information expression forms.

12. A multi-dimensional information loading structure for smart city Internet of Things, characterized in that, The target emitter has at least two information loading areas formed on its surface, which are used to load visible light information and infrared information, respectively. The information loading region is configured to encode the information to be loaded into optical response distribution features in the corresponding dimension using at least one of spatial dimension, spectral dimension, angular dimension and surface reflectance characteristic dimension. The information loading area has different optical response characteristics in the visible light band and the infrared band, so as to form mutually independent encoded information in the visible light band and the infrared band, and realize the compatible loading of dual-band information.

13. The multi-dimensional information loading structure for smart city IoT according to claim 12, characterized in that, The target emitter adopts a metal structure, and infrared information loading area and visible light information loading area are planned on the surface of the metal structure; Micro- and nano-structures are fabricated on the surface of the infrared information loading region using laser processing technology to achieve the control of infrared emissivity or infrared radiation intensity; A polymer film is integrated into the visible light information loading area, and a low-absorption infrared pigment is sprayed onto the surface of the polymer film to achieve color control.

14. The multi-dimensional information loading structure for smart city IoT according to claim 13, characterized in that, Low-absorption pigments in the infrared band include any one or any combination of two or more of the following: red pigments, yellow pigments, blue pigments, and white pigments; red pigments are iron oxide particles; yellow pigments are goethite particles or silicon particles; blue pigments are Prussian blue particles; and white pigments are zinc oxide particles.

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