Full-day biomimetic polarized light compass orientation method, system, equipment and medium

Abstract

This invention provides an all-day biomimetic polarization compass orientation method, system, device, and medium, including: calculating the current solar altitude angle based on the observation time and the carrier's latitude and longitude; calculating the degree of polarization of each pixel based on the current sky polarization image, obtaining the overall polarization degree index and the low polarization degree ratio index; determining the sky polarization state based on the current solar altitude angle, the overall polarization degree index, and the low polarization degree ratio index, and selecting the current orientation mode: when the current orientation mode is an atmospheric polarization vector orthogonal orientation mode, calculating and outputting the carrier's heading angle based on the polarization vector orthogonality method; when the current orientation mode is a solar spot orientation mode, calculating and outputting the carrier's heading angle based on an orientation algorithm that extracts the centroid of the solar spot from the polarization image. This invention is applicable to all-weather autonomous orientation and navigation of mobile platforms, and can provide high-precision azimuth information under conditions of no satellite or satellite loss of lock.

Description

Technical Field

[0001] This invention relates to the field of navigation and orientation technology, specifically to a daytime biomimetic polarized light compass orientation method, system, device, and medium. Background Technology

[0002] A polarized light compass is a biomimetic navigation technology that mimics the orientation sense of arthropods (such as desert ants and bees) using polarized light from the sky. Based on Rayleigh scattering theory, sunlight forms specific polarization patterns within various scattering angle ranges after entering the atmosphere. The polarization direction and degree exhibit a predictable distribution pattern with the sun's position, allowing the sun's orientation and further heading angle to be calculated even when the sun is not visible by measuring the sky's polarization field.

[0003] In recent years, with the rapid development of polarization imaging technology and computational models, polarization compasses based on the orthogonal method of sky polarization vectors can achieve orientation accuracy of less than 1° in the morning, evening, and under low to medium solar altitude angle conditions. However, this type of method is easily limited in the following scenarios:

[0004] (1) Significant problem of weak polarization at noon: When the solar altitude angle is high (especially greater than 60°~70°), the degree of polarization of the sky is significantly reduced and the gradient of polarization direction is weakened, which leads to the deterioration of the mathematical solution conditions of the polarization vector orthogonal method, and the solution is unstable or even jumps.

[0005] (2) Clouds and aerosols cause polarization field degradation: In environments with thin clouds, local cloud cover, or increased aerosol concentration, the overall polarization degree of the sky decreases or the polarization degree of local areas decreases, which significantly increases the polarization angle noise and thus affects the accuracy of the solution based on polarization characteristics.

[0006] (3) The feasibility of solar spot imaging varies with the environment: When the sun is within the field of view, the solar elevation angle is large, and the sky is clear, the direction estimation accuracy (<0.2°) can be obtained by extracting the centroid of the solar spot through image processing. However, when the sun is blocked or the elevation angle is low, the solar spot is not usable.

[0007] In summary, the key issue in current polarization compass research is how to intelligently switch between the polarization vector orthogonal method and the orientation algorithm based on extracting the centroid of the solar spot from polarization images under different solar altitude angles, weather conditions, and polarization field qualities, so as to ensure that a stable and reliable heading angle can be obtained under various environments. Summary of the Invention

[0008] Existing technologies lack an adaptive switching mechanism that can simultaneously make comprehensive judgments based on the quality of the sky polarization field and the geometric position of the sun. Furthermore, no method has been found to accurately identify weak or degraded polarization states by introducing an overall polarization degree threshold and a low polarization degree proportion threshold, thus ensuring high-precision orientation throughout the day. Therefore, this invention provides a biomimetic polarization compass orientation method, system, device, and medium for all-day operation. This method, by introducing methods including but not limited to an overall polarization degree threshold, a low polarization degree proportion threshold, and a solar altitude angle threshold, achieves intelligent judgment of the sky polarization state and adaptive switching between the polarization vector orthogonal method and the orientation algorithm based on extracting the centroid of the solar spot from a polarization image. This fundamentally improves the robustness and accuracy of the polarization compass under complex conditions such as weak polarization, cloud cover, and midday. It is applicable to high-precision heading calculations for platforms such as UAVs, unmanned vehicles, and unmanned surface vessels under conditions of satellite absence or satellite loss of lock.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] On the one hand, a biomimetic polarized light compass orientation method is provided for all-day conditions, including the following steps:

[0011] Calculate the current solar altitude angle based on the observation time and the latitude and longitude of the carrier;

[0012] Acquire a polarization image of the current sky, calculate the degree of polarization of each pixel based on the polarization image, obtain a polarization degree distribution image, and calculate the overall polarization degree index and the low polarization degree proportion index. The overall polarization degree index is the average polarization degree or weighted average polarization degree of the polarization degree distribution image, and the low polarization degree proportion index is the ratio of the number of pixels in the polarization degree distribution image with a polarization degree lower than a preset polarization degree threshold to the total number of pixels in the polarization degree distribution image.

[0013] Based on the current solar altitude angle, overall polarization index, and low polarization percentage index, determine the sky polarization state and select the current orientation mode:

[0014] When the current orientation mode is the atmospheric polarization vector orthogonal orientation mode, the carrier heading angle is calculated based on the polarization vector orthogonal method and output as the current orientation result;

[0015] When the current orientation mode is the solar spot orientation mode, the orientation algorithm based on the polarization image to extract the centroid of the solar spot calculates the carrier heading angle and outputs it as the current orientation result.

[0016] On the other hand, a biomimetic polarized light compass orientation system for all-day operation is provided, comprising a polarization camera unit, an inertial measurement unit, a solar ephemeris storage unit, and a processing unit. The polarization camera unit is used to acquire polarized images of the sky and full-field images including solar flares. The inertial measurement unit is used to output the attitude information of the carrier. The solar ephemeris storage unit is used to provide a solar direction vector corresponding to the observation time and the carrier's latitude and longitude. The processing unit includes:

[0017] The first module is used to calculate the current solar altitude angle based on the observation time and the latitude and longitude of the carrier;

[0018] The second module is used to calculate the degree of polarization of each pixel based on the current polarization image of the sky, obtain a polarization degree distribution image, and calculate the overall polarization degree index and the low polarization degree proportion index. The overall polarization degree index is the average polarization degree or weighted average polarization degree of the polarization degree distribution image, and the low polarization degree proportion index is the ratio of the number of pixels with a polarization degree lower than a preset polarization degree threshold in the polarization degree distribution image to the total number of pixels in the polarization degree distribution image.

[0019] The third module is used to determine the sky polarization state based on the current solar altitude angle, overall polarization index, and low polarization ratio index, and to select the current orientation mode:

[0020] The fourth module is used to calculate and output the carrier heading angle based on the polarization vector orthogonal orientation method when the current orientation mode is the atmospheric polarization vector orthogonal orientation mode, as the current orientation result;

[0021] The fifth module is used to calculate the carrier heading angle and output it as the current orientation result when the current orientation mode is the solar spot orientation mode, based on the orientation algorithm that extracts the centroid of the solar spot from the polarization image.

[0022] On the other hand, the present invention provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described biomimetic polarization compass orientation method for all-day conditions.

[0023] On the other hand, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described biomimetic polarized compass orientation method for all-day conditions.

[0024] On the other hand, the present invention provides a computer program product stored on a computer-readable storage medium and including computer instructions that, when executed by a processor, cause an electronic device to implement the steps of the above-described biomimetic polarization compass orientation method for all-day conditions.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] To overcome the shortcomings of existing polarized light compasses, such as increased orientation error under weak polarization conditions at noon and instability of polarization field under cloud interference, this invention proposes a full-day biomimetic polarized light compass orientation method, which is a full-day biomimetic polarized light compass orientation method that combines the overall polarization degree threshold, the low polarization degree proportion threshold, and the solar altitude angle threshold.

[0027] Specifically, the data acquired by the polarization compass of this invention includes polarization images, observation time, carrier latitude and longitude, IMU attitude information, etc. Based on the observation time and carrier latitude and longitude, the current solar altitude angle is calculated; based on the current sky polarization image, the degree of polarization of each pixel is calculated to obtain a polarization degree distribution image; the overall polarization degree index and the low polarization degree proportion index are obtained, where the overall polarization degree index is the average polarization degree or weighted average polarization degree of the polarization degree distribution image, and the low polarization degree proportion index is the ratio of the number of pixels in the polarization degree distribution image with a polarization degree lower than a preset polarization degree threshold to the total number of pixels in the polarization degree distribution image; based on the current solar altitude angle, the overall polarization degree index, and the low polarization degree proportion index, the sky polarization state is determined, and the current orientation mode is selected. Based on the current solar altitude angle, overall polarization degree index, and low polarization degree ratio index, the quality of the sky polarization field is comprehensively determined, and the current orientation mode is intelligently selected. When the current orientation mode is the atmospheric polarization vector orthogonal orientation mode, the carrier's heading angle is calculated and output based on the polarization vector orthogonal method. When the current orientation mode is the solar spot orientation mode, the carrier's heading angle is calculated and output based on the orientation algorithm that extracts the centroid of the solar spot from the polarization image. In this way, stable and high-precision heading calculation is achieved all day and all weather conditions.

[0028] Experiments have confirmed that the biomimetic polarization compass orientation method proposed in this invention can maintain an orientation error of less than 0.2° in scenarios where traditional polarization compasses are prone to failure, such as midday, thin clouds, and partial obstruction, thus significantly improving the robustness and practicality of the system.

[0029] This invention improves system robustness and is applicable to a wider range of unmanned system applications. The method can be used on platforms such as drones, unmanned vehicles, and unmanned surface vessels to provide continuous and stable heading information even in the absence of satellite signals.

[0030] In summary, this invention proposes a biomimetic polarization compass orientation method for all-day conditions. By using an orientation algorithm based on intelligent selection of polarization vectors for orthogonal orientation or extraction of the solar spot centroid from polarization images, it solves the problem of decreased accuracy of polarization compasses in various scenarios during all-day conditions. This method achieves high-precision carrier azimuth angle calculation in all weather conditions and has broad application value. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of a daytime biomimetic polarized light compass orientation method in one embodiment;

[0033] Figure 2 This diagram illustrates the relationship between the solar meridian azimuth, the solar direction vector, and the vehicle's heading angle.

[0034] Figure 3 This is a structural block diagram of an electronic device provided in one embodiment. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described through specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] In one embodiment, a biomimetic polarized light compass orientation method is provided for daytime operation, comprising the following steps:

[0037] Calculate the current solar altitude angle based on the observation time and the latitude and longitude of the carrier;

[0038] The polarization image of the current sky is acquired, and the degree of polarization of each pixel is calculated based on the polarization image to obtain the polarization degree distribution image. The overall polarization degree index and the low polarization degree proportion index are obtained. The overall polarization degree index is the average polarization degree or weighted average polarization degree of the polarization degree distribution image, and the low polarization degree proportion index is the ratio of the number of pixels in the polarization degree distribution image with a polarization degree lower than the preset polarization degree threshold to the total number of pixels in the polarization degree distribution image.

[0039] Based on the current solar altitude angle, overall polarization index, and low polarization ratio index, determine the sky polarization state and select the current orientation mode;

[0040] When the current orientation mode is the atmospheric polarization vector orthogonal orientation mode, the carrier heading angle is calculated and output based on the polarization vector orthogonal method, which serves as the current orientation result. When the current orientation mode is the solar spot orientation mode, the carrier heading angle is calculated and output based on the orientation algorithm that extracts the centroid of the solar spot from the polarization image, which serves as the current orientation result.

[0041] In the above embodiments, specifically, the method for selecting the current orientation mode is as follows: when the overall polarization degree index is lower than the preset overall polarization degree threshold, or the low polarization degree ratio index is greater than the preset ratio threshold, or the solar altitude angle is greater than the preset solar altitude angle threshold, it is determined that the current sky is weakly polarized or the sun is within the field of view, and the current orientation mode is selected as the solar spot orientation mode.

[0042] In other cases, the current orientation mode is selected as the orientation mode based on the orthogonality of atmospheric polarization vectors. Specifically, when the overall polarization degree index is not lower than the preset overall polarization degree threshold, the low polarization degree proportion index is not greater than the preset proportion threshold, and the solar altitude angle is not greater than the preset solar altitude angle threshold, the current orientation mode is selected as the orientation mode based on the orthogonality of atmospheric polarization vectors.

[0043] The above embodiments employ the polarization vector orthogonal method under conditions of high overall polarization degree, small proportion of low polarization degree, and low solar altitude angle, and employ a orientation algorithm based on extracting the centroid of the solar spot from the polarization image under conditions of reduced overall polarization degree, increased proportion of low polarization degree, or high solar altitude angle. This enables adaptive high-precision heading calculation for different sky polarization states throughout the day and significantly reduces orientation errors in weak polarization environments at noon and under complex weather conditions.

[0044] The above embodiments, by introducing methods including but not limited to the overall polarization degree threshold, the low polarization degree proportion threshold, and the solar altitude angle threshold, realize intelligent determination of the sky polarization state and adaptive switching between the polarization vector orthogonal method and the solar spot extraction method. They are applicable to high-precision heading calculation for platforms such as UAVs, unmanned vehicles, and unmanned boats under conditions of no satellite or satellite loss of lock.

[0045] The above embodiments introduce polarization field quality assessment indicators, including overall polarization degree index and low polarization degree ratio index, to improve the scientific nature and accuracy of the switching logic. Through analysis of overall polarization degree and low polarization degree ratio, various weak polarization conditions can be accurately identified. A triple judgment mechanism is established, making orientation mode switching more comprehensive and reliable. Whether it's noon weak polarization, cloud obstruction, aerosol enhancement, or the sun entering the field of view, this method can automatically switch to the optimal orientation algorithm, significantly improving orientation accuracy in complex environments. Compared to traditional polarization compasses that rely solely on sky polarization patterns, this invention can maintain an orientation error within 0.2° even under various complex lighting conditions such as noon weak polarization and local cloud obstruction, significantly improving orientation stability and robustness throughout the day, and is clearly superior to traditional polarization compass orientation schemes.

[0046] In any of the above embodiments, the preset solar altitude angle threshold is a solar altitude angle between 60° and 90°. Furthermore, the preset solar altitude angle threshold is preferably 70°, so that when the solar altitude angle is large and the sun is within the field of view, the solar spot orientation mode is preferentially adopted, improving orientation stability under weak polarization conditions.

[0047] In any of the above embodiments, the overall polarization degree threshold is preferably in the range of 0.1 to 0.5. When the overall polarization degree is lower than the overall polarization degree threshold, the sky is considered to be in a weakly polarized or unstable polarization mode state, thereby triggering the solar spot orientation mode.

[0048] The low polarization degree ratio index is the ratio of the number of pixels in the polarization degree distribution image with a polarization degree lower than the preset polarization degree threshold DOP_low to the total number of pixels in the polarization degree distribution image. The preset polarization degree threshold is preferably in the range of 0.1 to 0.3, and the preset ratio threshold is preferably in the range of 0.3 to 0.7. When the low polarization degree ratio index is greater than the preset low polarization degree ratio threshold, it is determined that the atmospheric polarization mode is significantly affected by cloud cover or aerosols, thus triggering the solar spot orientation mode.

[0049] In any of the above embodiments, calculating the heading angle of the carrier based on the polarization vector orthogonal method is a commonly used orientation algorithm in the field. Specifically, it includes: calculating the polarization angle based on the polarization image, solving the azimuth angle of the solar meridian by utilizing the orthogonality of the sky polarization vector on the solar meridian, and then calculating the heading angle of the carrier by combining the solar ephemeris information.

[0050] In one embodiment, the proposed orientation algorithm based on extracting the centroid of the solar spot from a polarization image calculates the carrier's heading angle, including:

[0051] Acquire full-field images containing sunspots or extract sunspot regions using intensity components of polarized images;

[0052] Image processing algorithms are used to extract the centroid of the sunspot from the sunspot region;

[0053] Imaging relationships are established using the projection model of the selected lens, and the position of the solar spot centroid in the image coordinate system is converted into a direction vector in the sensor coordinate system using camera intrinsic parameters;

[0054] The attitude information provided by the inertial measurement unit is obtained and the solar direction vector in the local horizontal coordinate system is obtained by consulting the solar ephemeris. The heading angle of the vehicle is solved by coordinate transformation, including: using the observation time and latitude and longitude, obtaining the solar direction vector in the local horizontal coordinate system from the publicly available solar ephemeris or solar position calculation model, and combining the roll angle and pitch angle provided by the inertial measurement unit to transform the solar direction vector in the sensor coordinate system to the vehicle system. The heading angle of the vehicle can be obtained by calculating the angle between the solar meridian azimuth angle and the solar direction vector in the vehicle coordinate system.

[0055] Reference Figure 2 , Figure 2 This diagram illustrates the relationship between the solar meridian azimuth angle, the solar direction vector, and the vehicle's heading angle. This represents the azimuth angle of the solar meridian, which is the solar direction vector in the local horizontal coordinate system. This represents the solar direction vector in the carrier's coordinate system, which is the angle between the current orientation and the solar meridian. This represents the vehicle's heading angle, which is defined here as the angle between the vehicle's forward direction and the local north direction. Given the time of the photograph and the latitude and longitude of the observation point, it can be obtained through solar ephemeris and time information. The solar azimuth angle is obtained by calculating the solar azimuth angle in the carrier's coordinate system. Therefore, the formula for obtaining the carrier's heading angle is: .

[0056] In the above embodiments, image processing algorithms are used to extract the centroid of the sunspot from the sunspot region. Specific implementation methods include, but are not limited to: filtering the full-field image, thresholding, and performing morphological opening and closing operations to remove noise, then calculating the geometric center of the sunspot pixels as the centroid; or, using least-squares ellipse fitting to the edge points of the sunspot to obtain the center of the sunspot circle as its centroid. Both algorithms can be selected according to the scene and ensure that the estimation error of the extracted sunspot centroid is less than 0.2°.

[0057] In another embodiment, a biomimetic polarized light compass orientation system for all-day operation is provided, comprising a polarization camera unit, an inertial measurement unit, a solar ephemeris storage unit, and a processing unit. The polarization camera unit is used to acquire polarized images of the sky and full-field images including solar flares. The inertial measurement unit is used to output the attitude information of the carrier. The solar ephemeris storage unit is used to provide a solar direction vector corresponding to the observation time and the latitude and longitude of the carrier. The processing unit includes:

[0058] The first module is used to calculate the current solar altitude angle based on the observation time and the latitude and longitude of the carrier;

[0059] The second module is used to calculate the degree of polarization of each pixel based on the current polarization image of the sky, obtain a polarization degree distribution image, and calculate the overall polarization degree index and the low polarization degree proportion index. The overall polarization degree index is the average polarization degree or weighted average polarization degree of the polarization degree distribution image, and the low polarization degree proportion index is the ratio of the number of pixels with a polarization degree lower than a preset polarization degree threshold in the polarization degree distribution image to the total number of pixels in the polarization degree distribution image.

[0060] The third module is used to determine the sky polarization state based on the current solar altitude angle, overall polarization index, and low polarization ratio index, and to select the current orientation mode:

[0061] The fourth module is used to calculate and output the carrier heading angle based on the polarization vector orthogonal orientation method when the current orientation mode is the atmospheric polarization vector orthogonal orientation mode, as the current orientation result;

[0062] The fifth module is used to calculate the carrier heading angle and output it as the current orientation result when the current orientation mode is the solar spot orientation mode, based on the orientation algorithm that extracts the centroid of the solar spot from the polarization image.

[0063] The implementation methods of each component module in the all-day biomimetic polarized light compass orientation system provided in the above embodiments can be implemented based on the corresponding methods described in any of the foregoing embodiments.

[0064] The acquisition of polarization images of the sky and the calculation of polarization field information are achieved through a polarization camera unit. The degree of polarization (DOP) and angle of polarization (AOP) of each pixel are calculated based on polarization images with different polarizer orientations. On this basis, the overall polarization degree index DOP_mean is calculated using the overall average or weighted average polarization degree of the polarization field to evaluate the global polarization intensity of the sky. The low polarization degree ratio R_low is calculated using the ratio of the number of pixels in the polarization degree distribution image with a polarization degree lower than a preset polarization degree threshold DOP_low to the total number of pixels in the polarization degree distribution image, which is used to quantify the degree of polarization field degradation.

[0065] The solar altitude angle H is obtained from the solar ephemeris based on the observation time and the carrier's latitude and longitude. The level of the solar altitude angle reflects whether the sun is within the imaging field of view.

[0066] The system proposes three decision logics to adaptively select the current orientation mode, with different orientation modes corresponding to different orientation algorithms.

[0067] (1) Overall polarization threshold

[0068] When the overall polarization degree is lower than the preset overall polarization degree threshold, it indicates that the overall polarization of the sky polarization field is weak. At this time, the error of the polarization vector orthogonal method is large, and the mode should be switched to the solar spot orientation mode.

[0069] (2) Threshold for low polarization degree

[0070] When the proportion of low polarization degree exceeds the preset threshold for low polarization degree, that is, the proportion of low polarization degree region is too large, it indicates that the polarization field is significantly affected by clouds, aerosols, etc. At this time, the reliability of polarization angle data is poor, and the mode of solar spot orientation should be switched.

[0071] (3) Solar altitude angle threshold

[0072] When the solar elevation angle is greater than the preset solar elevation angle threshold, i.e., when the solar elevation angle is too high, the degree of polarization naturally weakens, the calculation accuracy of the polarization vector orthogonal method decreases, and the solar spot appears stably in the field of view. The solar spot orientation mode should be switched.

[0073] In other cases, the current orientation mode is selected as the orientation mode based on the orthogonality of atmospheric polarization vectors. Specifically, when the overall polarization degree index is not lower than the preset overall polarization degree threshold, the low polarization degree proportion index is not greater than the preset proportion threshold, and the solar altitude angle is not greater than the preset solar altitude angle threshold, the current orientation mode is selected as the orientation mode based on the orthogonality of atmospheric polarization vectors.

[0074] Orientation model based on orthogonal atmospheric polarization vectors: Under conditions of good polarization field quality, a solution model is constructed using polarization angle measurements and the orthogonal distribution characteristics of sky polarization vectors along the solar meridian. The solar meridian azimuth angle is calculated, and then the vehicle's heading angle is obtained by combining solar ephemeris data and attitude angles. This model has a high accuracy advantage under conditions of morning, evening, and moderate solar altitude angles.

[0075] Solar spot orientation mode: When the polarization field degrades or the solar altitude angle is large, the solar spot region is extracted from the full field of view image and the centroid of the spot is calculated. The direction of sunlight is derived by combining the lens imaging model, and coordinate transformation is completed using IMU attitude angle and solar ephemeris data to finally obtain the carrier heading angle. This mode has significant stability at noon, when atmospheric transparency is high, or when the degree of polarization is unstable.

[0076] The system automatically selects the current orientation mode and then the corresponding orientation algorithm through the three judgment logics mentioned above. It can output stable and reliable heading results under different weather conditions and different solar geometry, achieving high-precision navigation all day long.

[0077] The all-day bionic polarized compass orientation system provided in the above embodiments can be installed on mobile platforms such as drones, unmanned vehicles, or unmanned boats to provide high-precision autonomous heading information all day long when there are no satellite navigation signals or when satellites are lost.

[0078] Figure 3 The figure shows a block diagram of an electronic device according to an embodiment, such as Figure 3 As shown, the electronic device includes one or more processors and a memory. The memory stores a computer program, and when the processor executes the computer program, it implements the steps of the all-day biomimetic polarization compass orientation method provided in any of the above embodiments. The processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. The memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc.

[0079] In one example, the electronic device may also include input devices and output devices, which are interconnected via a bus system and / or other forms of connection mechanism (not shown).

[0080] Of course, for the sake of simplicity, Figure 3 Only some of the components of the electronic device relevant to this application are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0081] Embodiments of the present invention may also be computer-readable storage media storing a computer program thereon, which, when executed by a processor, implements the steps of the all-day biomimetic polarization compass orientation method provided in any of the above embodiments. The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may, for example, include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0082] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0083] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0084] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0085] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application should not be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0086] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A biomimetic polarized light compass orientation method for all-day illumination, characterized in that, Includes the following steps: Calculate the current solar altitude angle based on the observation time and the latitude and longitude of the carrier; Acquire a polarization image of the current sky, calculate the degree of polarization of each pixel based on the polarization image, obtain a polarization degree distribution image, and calculate the overall polarization degree index and the low polarization degree proportion index. The overall polarization degree index is the average polarization degree or weighted average polarization degree of the polarization degree distribution image, and the low polarization degree proportion index is the ratio of the number of pixels in the polarization degree distribution image with a polarization degree lower than a preset polarization degree threshold to the total number of pixels in the polarization degree distribution image. Based on the current solar altitude angle, overall polarization index, and low polarization percentage index, the sky polarization state is determined, and the current orientation mode is selected, including: When the overall polarization index is lower than the preset overall polarization threshold, or the low polarization ratio index is greater than the preset ratio threshold, or the solar altitude angle is greater than the preset solar altitude angle threshold, it is determined that the current sky is weakly polarized or the sun is within the field of view, and the current orientation mode is selected as the solar spot orientation mode. When the overall polarization degree index is not lower than the preset overall polarization degree threshold, the low polarization degree ratio index is not greater than the preset ratio threshold, and the solar altitude angle is not greater than the preset solar altitude angle threshold, the current orientation mode is selected as the orientation mode based on the orthogonality of atmospheric polarization vectors. When the current orientation mode is the atmospheric polarization vector orthogonal orientation mode, the carrier heading angle is calculated based on the polarization vector orthogonal method and output as the current orientation result; When the current orientation mode is the solar spot orientation mode, the orientation algorithm based on the polarization image to extract the centroid of the solar spot calculates the carrier heading angle and outputs it as the current orientation result.

2. The all-day biomimetic polarized light compass orientation method according to claim 1, characterized in that, The preset solar altitude angle threshold is a solar altitude angle between 60° and 90°.

3. The all-day biomimetic polarized light compass orientation method according to claim 1, characterized in that, The overall polarization threshold value ranges from 0.1 to 0.

5.

4. The all-day biomimetic polarized light compass orientation method according to claim 1, characterized in that, The preset polarization threshold value ranges from 0.1 to 0.3, and the preset proportion threshold value ranges from 0.3 to 0.

7.

5. The all-day biomimetic polarized light compass orientation method according to any one of claims 1 to 4, characterized in that, The calculation of the carrier heading angle based on the polarization vector orthogonal method includes: The polarization angle is calculated based on the polarization image, and the azimuth angle of the solar meridian is solved by utilizing the orthogonality of the sky polarization vector on the solar meridian. Then, the heading angle of the carrier is calculated by combining the solar ephemeris information.

6. The all-day biomimetic polarized light compass orientation method according to any one of claims 1 to 4, characterized in that, An orientation algorithm based on extracting the centroid of the solar spot from polarization images is used to calculate the carrier's heading angle, including: Acquire full-field images containing sunspots or extract sunspot regions using intensity components of polarized images; Image processing algorithms are used to extract the centroid of the sunspot from the sunspot region; Imaging relationships are established using the projection model of the selected lens, and the position of the solar spot centroid in the image coordinate system is converted into a direction vector in the sensor coordinate system using camera intrinsic parameters; The attitude information provided by the inertial measurement unit is obtained, and the solar direction vector in the local horizontal coordinate system is obtained by consulting the solar ephemeris. The vehicle heading angle is then calculated through coordinate transformation, including: Using observation time and latitude and longitude, obtain the solar direction vector in the local horizontal coordinate system from publicly available solar ephemeris or solar position calculation models; By combining the roll and pitch angles provided by the inertial measurement unit, the solar direction vector in the sensor coordinate system is transformed to the carrier coordinate system to obtain the solar direction vector in the carrier coordinate system; The azimuth angle of the solar meridian is obtained based on the solar direction vector in the local horizontal coordinate system; The heading angle of the vehicle can be obtained by calculating the angle between the azimuth angle of the solar meridian and the solar direction vector in the vehicle's coordinate system.

7. A biomimetic polarized light compass orientation system for all-day illumination, characterized in that, The system includes a polarization camera unit, an inertial measurement unit, a solar ephemeris storage unit, and a processing unit. The polarization camera unit is used to acquire polarized images of the sky and full-field images including solar flares. The inertial measurement unit is used to output the attitude information of the carrier. The solar ephemeris storage unit is used to provide a solar direction vector corresponding to the observation time and the latitude and longitude of the carrier. The processing unit includes: The first module is used to calculate the current solar altitude angle based on the observation time and the latitude and longitude of the carrier; The second module is used to calculate the degree of polarization of each pixel based on the current polarization image of the sky, obtain a polarization degree distribution image, and calculate the overall polarization degree index and the low polarization degree proportion index. The overall polarization degree index is the average polarization degree or weighted average polarization degree of the polarization degree distribution image, and the low polarization degree proportion index is the ratio of the number of pixels with a polarization degree lower than a preset polarization degree threshold in the polarization degree distribution image to the total number of pixels in the polarization degree distribution image. The third module is used to determine the sky polarization state based on the current solar altitude angle, overall polarization index, and low polarization ratio index, and to select the current orientation mode, including: When the overall polarization index is lower than the preset overall polarization threshold, or the low polarization ratio index is greater than the preset ratio threshold, or the solar altitude angle is greater than the preset solar altitude angle threshold, it is determined that the current sky is weakly polarized or the sun is within the field of view, and the current orientation mode is selected as the solar spot orientation mode. When the overall polarization degree index is not lower than the preset overall polarization degree threshold, the low polarization degree ratio index is not greater than the preset ratio threshold, and the solar altitude angle is not greater than the preset solar altitude angle threshold, the current orientation mode is selected as the orientation mode based on the orthogonality of atmospheric polarization vectors. The fourth module is used to calculate and output the carrier heading angle based on the polarization vector orthogonal orientation method when the current orientation mode is the atmospheric polarization vector orthogonal orientation mode, as the current orientation result; The fifth module is used to calculate the carrier heading angle and output it as the current orientation result when the current orientation mode is the solar spot orientation mode, based on the orientation algorithm that extracts the centroid of the solar spot from the polarization image.

8. An electronic device comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the all-day biomimetic polarized light compass orientation method as described in claim 1.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the all-day biomimetic polarized light compass orientation method as described in claim 1.

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