Polarization navigation method and polarization navigation differential reference station based on light and shadow flow

Abstract

The application discloses a light and shadow circulation type polarization navigation differential reference station and a polarization navigation method. The light and shadow circulation type polarization navigation differential reference station comprises a rotating table top arranged on the top of a reference station main body, a plurality of polarized light windows are arranged on the first surface of the rotating table top, a transmission mechanism is connected with the second surface of the rotating table top and is used for controlling the rotating table top to rotate, an imaging sensor is arranged below the rotating table top, the central axis of the imaging sensor coincides with the central axis of any one of the plurality of polarized light windows, the optical lens of the imaging sensor is parallel to the mounting plane corresponding to the rotating table top, and a sampling controller is arranged on the inner side wall of the reference station main body and is used for controlling the imaging sensor to sample image data in response to the rotating table top rotating by a preset angle. According to the embodiment of the application, the cyclic collection of the plurality of polarization optical channels can be realized, and the sampling precision of the polarization differential reference station can be effectively improved.

Description

Technical Field

[0001] This application belongs to the field of navigation technology, and in particular relates to a light-shadow flow polarization navigation differential reference station and polarization navigation method. Background Technology

[0002] Polarized light navigation is a novel navigation method with advantages such as autonomy and no cumulative error. However, its polarization orientation accuracy is limited by the atmospheric environment. In cloudy or overcast conditions, the perpendicular relationship between the polarization vector and the solar vector is disrupted, introducing navigation errors. Existing polarization sensing devices, including point-source polarization sensors and image-based polarization sensors, all operate on a single-point detection mode of the sky's polarized light field, resulting in poor sampling accuracy and an inability to eliminate the aforementioned interference. Summary of the Invention

[0003] This application provides a light-shadow-flow polarization navigation differential reference station and polarization navigation method to at least solve the problem of poor sampling accuracy in single-point detection of sky polarization light field modes in related technologies.

[0004] In a first aspect, embodiments of this application provide a light-and-shadow-flow polarization navigation differential reference station, comprising:

[0005] A rotating platform is set on the top of the main body of the base station, and multiple polarization windows are provided on the first surface of the rotating platform;

[0006] A transmission mechanism is connected to the second surface of the rotating platform and is used to control the rotating platform to rotate with the top horizontal plane of the base station body as the plane of rotation.

[0007] An imaging sensor is disposed below the rotating stage, and the central axis of the imaging sensor coincides with the central axis of any one of the multiple polarization windows. The optical lens of the imaging sensor is parallel to the mounting plane corresponding to the rotating stage.

[0008] A sampling controller, located on the inner wall of the main body of the base station, is used to control the imaging sensor to sample image data in response to the rotation of the rotating platform at a preset angle.

[0009] In a second aspect, embodiments of this application provide a polarization navigation method, which is applied to a light-shadow-flow polarization navigation differential reference station as described in any embodiment of the first aspect. The reference station includes a rotating platform, a transmission mechanism, an imaging sensor, a sampling controller, and a heading collimator.

[0010] The method includes:

[0011] The rotating platform is controlled by a transmission mechanism to rotate with the top horizontal plane of the base station as the plane of rotation. Multiple polarization windows are provided on the first surface of the rotating platform.

[0012] In response to the rotating platform rotating at a preset angle, the imaging sensor is controlled by the sampling controller to sample image data.

[0013] The light and shadow flowing polarization navigation differential reference station and polarization navigation method of this application embodiment can realize the cyclic acquisition of multiple polarization optical channels by rotating the rotating table and the multiple polarization optical windows set on it. It has the advantages of high cyclic in-situ repeatability, cyclic alignment of polarization optical channels and imaging sensors, and automatic acquisition by imaging sensors. It is also low in cost and easy to implement, which can effectively improve the sampling accuracy of polarization differential reference station, thereby coping with navigation errors caused by atmospheric environmental interference. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a front view of the light and shadow flowing polarization navigation differential reference station provided in the embodiments of this application;

[0016] Figure 2 This is a cross-sectional view of the light and shadow flowing polarization navigation differential reference station provided in the embodiments of this application along the AA direction shown in the main view;

[0017] Figure 3 This is a schematic diagram of the transmission mechanism in the light and shadow flow polarization navigation differential reference station provided in the embodiments of this application;

[0018] Figure 4 This is a schematic flowchart of the polarization navigation method provided in the embodiments of this application.

[0019] Figure label:

[0020] Rotating table 100, polarizing window 110, transmission mechanism 200, cam divider 210, DC motor 220, transmission belt 230, position sensor 240, sampling controller 300, imaging sensor 400, heading collimator 500. Detailed Implementation

[0021] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application 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 only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0022] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0023] Polarized light navigation is a novel navigation method with advantages such as autonomy and no cumulative error. However, its polarization orientation accuracy is limited by the atmospheric environment. In cloudy or overcast conditions, the perpendicular relationship between the polarization vector and the solar vector is disrupted, introducing navigation errors. Existing polarization sensing devices, including point-source polarization sensors and image-based polarization sensors, all operate on a single-point detection mode of the sky's polarized light field, resulting in poor sampling accuracy and an inability to eliminate the aforementioned interference.

[0024] To address the problems in related technologies, this application provides a light-and-shadow-flow polarization navigation differential reference station and a polarization navigation method.

[0025] It should be noted that the light and shadow flow polarization navigation differential reference station and polarization navigation method in this application embodiment are inspired by satellite navigation technology. That is, in response to the ionospheric interference of broadcast messages, the reference station provides correction items for users, and pseudorange differential is used to cancel common errors. Furthermore, it is designed and implemented to take into account the random, unknown, and large-scale uniformity of atmospheric interference with polarized light, and can be applied to the autonomous navigation of UAVs.

[0026] The following description, in conjunction with the accompanying drawings, details the light-shadow-flow polarization navigation differential reference station provided in this application through specific embodiments and application scenarios.

[0027] refer to Figure 1 and Figure 2 These are, respectively, a front view of the light-shadow flowing polarization navigation differential reference station according to an embodiment of this application, and a cross-sectional view (i.e., AA cross-sectional view) of the light-shadow flowing polarization navigation differential reference station along the AA direction shown in the front view. Figure 1 and Figure 2 As shown, the light and shadow flowing polarization navigation differential reference station includes a rotating platform 100, a transmission mechanism 200, a sampling controller 300, an imaging sensor 400, and a heading collimator 500.

[0028] Specifically, a rotating platform 100 is disposed on the top of the base station body, and a plurality of polarizing windows 110 are disposed on the first surface of the rotating platform 100; a transmission mechanism 200 is connected to the second surface of the rotating platform 100 and is used to control the rotating platform 100 to rotate about the top horizontal plane of the base station body as the plane of rotation; an imaging sensor 400 is disposed below the rotating platform 100, and the central axis of the imaging sensor 400 coincides with the central axis of any one of the plurality of polarizing windows 110, and the optical lens of the imaging sensor 400 is parallel to the mounting plane of the rotating platform 100; a sampling controller 300 is disposed on the inner side wall of the base station body and is used to control the imaging sensor 400 to perform image data sampling in response to the rotating platform 100 rotating at a preset angle; a heading collimator 500 is detachably disposed above the base station body, including two collimators with precision collimation slots, used for two-point orientation to provide a heading reference.

[0029] Furthermore, Figure 3 A schematic diagram of the transmission mechanism 200 in the light-and-shadow flow polarization navigation differential reference station according to an embodiment of this application is shown. Figure 1 , Figure 2 and Figure 3 As shown, the transmission mechanism 200 includes: a cam divider 210, a DC motor 220, a transmission belt 230, and a position sensor 240.

[0030] The output end of the cam divider 210 is connected to the second surface of the rotary table 100, and the input end of the cam divider 210 is connected to the DC motor 220 through the transmission belt 230.

[0031] Optionally, the output shaft of the cam divider 210 coincides with the central axis of the rotary table 100.

[0032] Optionally, the cam divider 210 engages vertically and without clearance with an indexing plate on the output shaft, which has evenly distributed needle roller bearings, via a conjugate cam on the input shaft. The curved segment of the cam profile drives the needle roller bearings on the indexing plate to rotate the indexing plate, while the straight segment keeps the indexing plate stationary and self-locking. In this way, the output shaft completes a one-movement-one-stop indexing process with one rotation of the input shaft.

[0033] Optionally, the input end of the cam divider 210 is connected to the DC motor 220 via a transmission belt 230 for driving, and the output end flange is connected to the bottom (i.e. the second surface) of the rotary table 100 via bolts. The output end controls the rotary table 100 to perform intermittent rotational motion.

[0034] In some embodiments, the DC motor 220 is used to drive the input shaft of the cam divider 210 to rotate via the transmission belt 230 in response to power-on, so that the cam divider 210 controls the rotary table 100 to rotate with the top horizontal plane of the base station body as the plane of rotation.

[0035] In some embodiments, the position sensor 240 is connected to the cam divider 210 and is used to trigger the sampling controller 300 in response to the DC motor 220 rotating one revolution, so that the sampling controller 300 controls the imaging sensor 400 to perform image data sampling.

[0036] Optional, such as Figure 1 and Figure 2 As shown, the position sensor 240 comprises two parts: one part is a mechanical structure mounted on the input shaft of the cam divider 210; the other part is a photoelectric switch fixed on the side wall of the cam divider 210.

[0037] In other words, each rotation of the DC motor 220 triggers the position sensor 240 once, which in turn triggers the sampling controller 300, thereby controlling the imaging sensor 400 to sample data once. It should also be understood that each trigger of the imaging sensor 400 by the position sensor 240 corresponds to a preset angle rotation of the rotating platform 100. In this way, by controlling the rotation of the DC motor 220 through the sampling controller 300 and triggering the imaging sensor 400 through the position sensor 240, atmospheric polarization light field acquisition is achieved.

[0038] As an optional embodiment, a plurality of polarizing windows 110 are uniformly distributed circumferentially around the central axis of rotation of the rotating stage 100 on the first surface of the rotating stage 100. Each of the polarizing windows 110 includes a polarizing lens, and the installation polarization angles of the polarizing lenses of any two adjacent polarizing windows 110 differ by a preset angle.

[0039] Optionally, the plurality of polarization windows 110 includes four polarization windows 110, which are respectively disposed at four equal positions on the first surface of the rotating table 100.

[0040] Optionally, polarizing lenses with polarization angles of 0°, 45°, 90°, and 135° can be installed on the four polarization windows 110 respectively.

[0041] Optionally, a window may be opened at any one of the eight equal divisions on the first surface of the rotating platform 100 and an ultraviolet filter (ordinary UV filter) may be provided.

[0042] Thus, with windows opened at four equal divisions on the first surface of the rotating platform 100 and polarizing lenses with polarization angles of 0°, 45°, 90°, and 135° respectively, and with windows opened at any eight divisions on the first surface of the rotating platform 100 and ordinary UV lenses installed, the sampling controller 300 controls the DC motor 220 to rotate, which in turn drives the input shaft of the cam divider 210 to rotate via the transmission belt 230. This achieves intermittent rotation of the rotating platform 100, which is connected to the output flange of the cam divider 210, at its eight divisions on its plane. Consequently, every time the rotating platform 100 rotates 45°, the position sensor 240 is triggered, controlling the imaging sensor 400 to acquire atmospheric polarization images.

[0043] Therefore, in the light and shadow flowing polarization navigation differential reference station of this application embodiment, "light and shadow" refers to the polarization light signal and its imaging characteristics processed by the entire device. That is, five filters with different polarization angles are used to sequentially collect multi-angle polarization light fields by rotating the rotating platform 100, thereby forming optical information with directional differences, i.e., different light and shadow characteristics. "Flowing" refers to the dynamic working mechanism of the entire device. That is, the rotating platform 100 is driven by the cam divider 210 to achieve precise indexing rotation at eight equal positions, so that the five light windows set on it are cyclically switched.

[0044] In summary, by rotating the rotating platform 100 and setting multiple polarization windows 110 on it, cyclic acquisition of multiple polarization optical channels can be achieved. It has the advantages of high cyclic in-situ repeatability, cyclic alignment of polarization optical channels and imaging sensors, and automatic acquisition by imaging sensors. It is also low in cost and easy to implement, which can effectively improve the sampling accuracy of polarization differential reference station, thereby coping with navigation errors caused by atmospheric environmental interference.

[0045] Furthermore, this application also provides a polarization navigation method. It should be noted that the polarization navigation method can be applied to a light-shadow-flow polarization navigation differential reference station as described in any of the above embodiments, wherein the reference station includes a rotating platform, a transmission mechanism, an imaging sensor, a sampling controller, and a heading collimator.

[0046] Figure 4 A schematic flowchart of a polarization navigation method according to an embodiment of this application is shown. Figure 4 As shown, the polarization navigation method may specifically include the following steps: S401 to S405.

[0047] S401. The rotating platform is controlled by the transmission mechanism to rotate with the top horizontal plane of the base station body as the rotation plane. Multiple polarization windows are provided on the first surface of the rotating platform.

[0048] Optionally, the plurality of polarization windows includes four polarization windows, which are respectively disposed at four equal positions on the first surface of the rotating stage, and polarization lenses with polarization angles of 0°, 45°, 90° and 135° are respectively installed in the four polarization windows.

[0049] Optionally, windows can be opened at any of the eight equal divisions on the first surface of the rotating platform and ultraviolet filter lenses can be provided.

[0050] S402. In response to the rotating platform rotating at a preset angle, the imaging sensor is controlled by the sampling controller to sample image data.

[0051] In practice, in response to the DC motor being powered on, the input shaft of the cam divider is driven to rotate via the transmission belt, so that the cam divider controls the rotating table to rotate with the top horizontal plane of the base station as the plane of rotation; in response to the DC motor rotating one revolution, the position sensor triggers the sampling controller, so that the sampling controller controls the imaging sensor to sample image data.

[0052] Optionally, depending on the opening method of the light and shadow flow polarized optical window, when the rotating platform rotates one revolution, the acquired image data includes four polarized images and one unpolarized image.

[0053] S403. Starting with the unpolarized image, the four polarized images acquired subsequently are grouped together to calculate atmospheric polarization image data.

[0054] In some embodiments, a heading collimator is used to perform two-point orientation to provide a heading reference; starting from the unpolarized image, four subsequently acquired polarized images are grouped together, and the direction information of the atmospheric polarized image is determined based on the heading reference.

[0055] In practice, the heading collimator provides the direction reference for the polarization image. It includes two collimators with precision collimation slots. Before the acquisition work of the differential reference station begins, the black line is placed on the precision collimation slots. The heading of the black line is determined by the GPS module. Then, image sampling is performed. By identifying the direction of the black line in the image, the direction of the polarization image is indirectly obtained.

[0056] S404. Based on the atmospheric polarization image data and the pre-acquired heading information, calculate the target optical parameters of the atmosphere.

[0057] S405. Perform polarization navigation orientation based on the target optical parameters.

[0058] Therefore, by observing optical phenomena in the atmosphere, a polarization image of the atmosphere can be obtained. This involves using multiple filters with different polarization angles and sequentially acquiring multi-angle polarized light fields by rotating a rotating platform, thus forming optical information with directional differences. Based on the polarization image of the atmosphere and pre-calculated heading information, some optical parameters of the atmosphere can be calculated. Furthermore, these optical parameters can assist other polarization navigation sensors in achieving higher-precision orientation.

[0059] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0060] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0061] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0062] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0063] In this application, "multiple" means two or more (including two).

[0064] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0065] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0066] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A light-and-shadow-flow polarization navigation differential reference station, characterized in that, include: A rotating platform is set on the top of the main body of the base station, and multiple polarization windows are provided on the first surface of the rotating platform; A transmission mechanism is connected to the second surface of the rotating platform and is used to control the rotating platform to rotate with the top horizontal plane of the base station body as the plane of rotation. An imaging sensor is disposed below the rotating stage, and the central axis of the imaging sensor coincides with the central axis of any one of the multiple polarization windows. The optical lens of the imaging sensor is parallel to the mounting plane corresponding to the rotating stage. A sampling controller is disposed on the inner side wall of the main body of the base station, and is used to control the imaging sensor to sample image data in response to the rotation of the rotating platform at a preset angle; A heading collimator, detachably mounted above the main body of the reference station, includes two collimators with collimation slots for two-point orientation to provide a heading reference.

2. The base station according to claim 1, characterized in that, The transmission mechanism includes: a cam divider, a DC motor, a transmission belt, and a position sensor; The output end of the cam divider is connected to the second surface of the rotary table, and the input end of the cam divider is connected to the DC motor via the transmission belt; The DC motor is used to drive the input shaft of the cam divider to rotate via the transmission belt in response to power-on, so that the cam divider controls the rotating table to rotate with the top horizontal plane of the base station body as the plane of rotation; The position sensor is connected to the cam divider and is used to trigger the sampling controller in response to the DC motor rotating one revolution, so that the sampling controller controls the imaging sensor to perform image data sampling.

3. The base station according to claim 1, characterized in that, Multiple polarization windows are evenly distributed circumferentially around the central axis of the rotating platform on the first surface of the rotating platform. Each of the polarizing windows includes a polarizing lens, and the installation polarization angles of the polarizing lenses of any two adjacent polarizing windows differ by a preset angle.

4. The base station according to claim 3, characterized in that, The plurality of polarization windows includes four polarization windows, which are respectively disposed at four equal positions on the first surface of the rotating table; The four polarization windows are equipped with polarizing lenses with polarization angles of 0°, 45°, 90° and 135° respectively.

5. The base station according to claim 4, characterized in that, A window is opened at any one of the eight equal divisions on the first surface of the rotating platform and an ultraviolet filter lens is provided.

6. A polarization navigation method, characterized in that, The method is applied to the light and shadow flow polarization navigation differential reference station as described in any one of claims 1-5, wherein the reference station includes a rotating platform, a transmission mechanism, an imaging sensor, a sampling controller, and a heading collimator; The method includes: The rotating platform is controlled by a transmission mechanism to rotate with the top horizontal plane of the base station as the plane of rotation. Multiple polarization windows are provided on the first surface of the rotating platform. In response to the rotating platform rotating at a preset angle, the imaging sensor is controlled by the sampling controller to sample image data.

7. The method according to claim 6, characterized in that, The multiple polarization windows include four polarization windows, which are respectively located at four equal division positions on the first surface of the rotating stage. The four polarization windows are respectively equipped with polarizing lenses with polarization angles of 0°, 45°, 90°, and 135°. An ultraviolet filter lens is provided at any one of the eight equal division positions on the first surface of the rotating stage. When the rotating platform rotates one revolution, the acquired image data includes four polarized images and one unpolarized image.

8. The method according to claim 7, characterized in that, After the imaging sensor is controlled by the sampling controller to sample image data in response to the rotation of the rotating platform by a preset angle, the method further includes: Starting with the unpolarized image, four consecutively acquired polarized images are grouped together to calculate atmospheric polarization image data; Based on the atmospheric polarization image data and the pre-acquired heading information, the target optical parameters of the atmosphere are calculated; Polarization navigation and orientation are performed based on the target's optical parameters.

9. The method according to claim 8, characterized in that, The step of taking the unpolarized image as a starting point and then grouping four consecutively acquired polarized images into a set to calculate atmospheric polarization image data includes: Two-point orientation is performed using a heading collimator to provide a heading reference; Starting with the unpolarized image, four consecutively acquired polarized images are grouped together, and the direction information of the atmospheric polarized image is determined based on the heading reference.

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