Fiber free-space alignment communication apparatus, method, system, and medium

Abstract

The application provides an optical fiber free space alignment communication device, method, system and medium. The device comprises a memory, a processor, a camera at a preset fixed position, a double-shaft holder and an auxiliary identification background plate arranged on the double-shaft holder; an identifier is arranged on the auxiliary identification background plate, a light beam collimating lens is arranged in the identifier area, and a visible light laser beam generating device is arranged on the side of the light beam collimating lens away from another optical fiber free space alignment communication device; the processor is electrically interconnected with the memory, the camera and the double-shaft holder circuit; the processor is used for acquiring an image including the background plate in another optical fiber free space alignment communication device collected by the camera, and identifying the identifier on the background plate in the image; if the identifier in the image is identified, it is determined whether a light spot is included in the image; the angle to be deflected of the double-shaft holder is determined according to the result of whether the light spot exists, and the double-shaft holder is controlled to deflect according to the deflection angle.

Description

Technical Field

[0001] This application relates to communication technology, and more particularly to an optical fiber free space alignment communication device, method, system, and medium. Background Technology

[0002] With the ever-increasing speed of information technology transmission, fiber optic communication technology has become one of the main pillars of modern communication, playing a crucial role in modern telecommunications networks. Fiber optic communication has the advantages of high data rates and long transmission distances. However, in some situations, two optical transceivers need to communicate relative to each other and cannot be directly connected via wired means. This necessitates the design of a spatial optical communication device to optically align the fiber end faces of the two transceivers, allowing the transmitted beams from both to couple into the opposite fiber after passing through a free space, thereby achieving short-distance, small-area mobile communication.

[0003] In existing technologies for spatial alignment of optical fibers, an infrared camera at the transmitting end captures the coordinates of the receiving end, and then controls the deflection of the transmitting end to ensure the light beam reaches the receiving end. After receiving the light beam, the receiving end reflects it through a spatial light modulator and uses a beam splitter to split the beam into two parts. One part is incident on the receiving optical fiber, and the other part is incident on a four-quadrant detector. The optical axes of the four-quadrant detector and the receiving detector are strictly symmetrical about the beam splitter. Based on the beam spot coordinates on the four-quadrant detector, the beam reversal angle at the receiving end is adjusted so that the beam spot is located at the center of the four-quadrant detector, thus allowing the other path to reach the receiving optical fiber.

[0004] Existing technologies, due to the use of spatial light modulators, four-quadrant detectors, and other components, result in complex alignment device structures, stringent alignment conditions, and high costs. Furthermore, the need to continuously illuminate the beacon LED at the receiving end leads to high energy consumption. Summary of the Invention

[0005] This application provides an optical fiber free space alignment communication device, method, system, and medium to solve the problems of complex structure, harsh conditions, high cost, and high energy consumption in the prior art.

[0006] In a first aspect, this application provides an optical fiber free-space alignment communication device, comprising:

[0007] The system includes a memory, a processor, a camera at a preset fixed position, a dual-axis gimbal, and an auxiliary recognition background plate set on the dual-axis gimbal; an identifier is set on the auxiliary recognition background plate, a beam collimating lens is set in the area of ​​the identifier, and a visible light laser beam generating device is set on the side of the beam collimating lens that is away from the other optical fiber free space and aligned with the communication device.

[0008] The processor is interconnected with the memory, the camera, and the dual-axis gimbal circuit, respectively.

[0009] The memory is used to store computer programs; the camera is used to capture images, including a background plate, from another fiber optic free-space alignment communication device.

[0010] The processor is configured to read the computer program in the memory and perform the following operations:

[0011] Acquire images captured by the camera and identify the markers on the background board in the images;

[0012] If an identifier is identified in the image, it is determined whether the image contains a light spot, which is formed by a visible light laser beam emitted by a visible light laser beam generator to the side of another optical fiber free space aligned with the communication device.

[0013] The angle to be deflected by the dual-axis gimbal is determined based on the presence or absence of light spots, and the dual-axis gimbal is controlled to deflect according to the deflection angle to achieve unidirectional optical alignment between the two optical fiber free space alignment communication devices.

[0014] Optionally, the visible light laser beam generating device includes: a visible light laser, an optical fiber communication module, an optical fiber, and a beam splitter;

[0015] The visible light laser and the optical fiber communication module are connected to the beam splitter via optical fiber, and the beam splitter is connected to the optical path of the beam collimating lens via optical fiber.

[0016] The visible light laser is used to emit visible light through an optical fiber;

[0017] The optical fiber communication module is used to transmit non-visible light carrying information through an optical fiber;

[0018] The beam splitter is used to couple the visible light and the non-visible light to form a visible light laser beam, and to emit the visible light laser beam to the beam collimating lens through an optical fiber.

[0019] Optionally, the marker is circular; when the processor identifies the marker on the background in the image, it specifically performs the following tasks:

[0020] The image is input into the Hough Circle algorithm; the Hough Circle algorithm is used to identify whether the image contains a marker based on the shape of the marker.

[0021] Optionally, when determining whether the image includes a light spot, the processor specifically performs the following:

[0022] The image is cropped to remove areas other than the background area.

[0023] The cropped image is binarized according to a first preset pixel brightness threshold.

[0024] Perform mean filtering on the binarized image;

[0025] Determine whether the mean-filtered image contains pixels with a brightness greater than a second preset pixel brightness threshold;

[0026] If it is determined that the image includes pixels with brightness values ​​greater than the second preset pixel brightness threshold, then it is determined that the image includes light spots.

[0027] If it is determined that there are no pixels with brightness values ​​greater than the second preset pixel brightness threshold, then it is determined that the image does not contain light spots.

[0028] Optionally, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, the processor is specifically used for:

[0029] If a light spot is determined to exist, determine whether the light spot is aligned with the beam collimating lens in another fiber free space aligned communication device.

[0030] If it is determined that the beam collimating lens in the communication device is aligned with another fiber optic free space, then the deflection angle of the dual-axis gimbal is determined to be zero.

[0031] If it is determined that the beam collimating lens in another fiber optic free space alignment communication device is not aligned, then the coordinate deviation between the light spot and the beam collimating lens is determined, and the deflection angle of the dual-axis gimbal is determined based on the coordinate deviation.

[0032] Optionally, when determining whether the light spot is aligned with the beam collimating lens in another fiber-optic free-space aligned communication device, the processor is specifically used for:

[0033] Determine whether the proportion of the first pixel value in the preset region surrounding the collimating lens of the beam in the mean-filtered image is greater than a preset proportion threshold, wherein the first pixel value is a pixel value greater than a first preset pixel brightness threshold;

[0034] If the value is determined to be greater than the preset percentage threshold, then the light spot is aligned with the beam collimating lens in another fiber free space alignment communication device.

[0035] If the value is less than or equal to a preset percentage threshold, then the light spot is determined to be misaligned with the beam collimating lens in another fiber free space aligned communication device.

[0036] Optionally, when determining the coordinate deviation between the light spot and the collimating lens, the processor is specifically configured to:

[0037] The pixel with the largest pixel value among the pixels in the mean-filtered image that are greater than the second preset pixel brightness threshold is obtained.

[0038] The coordinates of the pixel with the largest pixel value are determined as the center coordinates of the light spot in the image coordinate system;

[0039] Determine the center coordinates of the beam collimating lens in the image coordinate system;

[0040] The center coordinates of the light spot in the image coordinate system and the center coordinates of the beam collimating lens in the image coordinate system are transformed into the center coordinates in the world coordinate system.

[0041] The coordinate deviation between the light spot and the collimating lens is determined based on the center coordinates of the light spot in the world coordinate system and the center coordinates of the beam collimating lens in the world coordinate system.

[0042] Optionally, after recognizing that the image includes a marker, the processor is further configured to:

[0043] The Hough's circular algorithm is used to determine the first coordinates of the marker in the image coordinate system.

[0044] The first coordinates of the markers in multiple images are averaged to obtain the first mean coordinates;

[0045] The first mean coordinates are converted to coordinates in the world coordinate system to obtain the second coordinates of the marker.

[0046] Optionally, when determining the angle to be deflected by the dual-axis gimbal based on the presence or absence of a light spot, the processor is further configured to:

[0047] If it is determined that there is no light spot, then obtain the second coordinates of the marker;

[0048] The angle to be deflected by the dual-axis gimbal is determined based on the second coordinate of the marker and the coordinates and dimensions of the dual-axis gimbal in the world coordinate system.

[0049] Optionally, after controlling the dual-axis gimbal to deflect according to the deflection angle, the processor is further configured to:

[0050] Perform the step of determining whether the image contains light spots;

[0051] Optionally, the fiber optic free space alignment communication device is mounted on the transceiver terminal;

[0052] The auxiliary recognition background plate is mounted on a dual-axis gimbal, which is located on the surface of the transceiver terminal and on the same surface as the camera. The auxiliary recognition background plates and cameras of the two transceiver terminals are arranged facing each other.

[0053] In a second aspect, this application provides a fiber optic free-space alignment communication method, the method being applied to the fiber optic free-space alignment communication device described in the first aspect, the method comprising:

[0054] Acquire images captured by the camera and identify the markers on the background board in the images;

[0055] If an identifier is identified in the image, it is determined whether the image contains a light spot, which is formed by a visible light laser beam emitted by a visible light laser beam generator to the side of another optical fiber free space aligned with the communication device.

[0056] The angle to be deflected by the dual-axis gimbal is determined based on the presence or absence of light spots, and the dual-axis gimbal is controlled to deflect according to the deflection angle to achieve unidirectional optical alignment between the two optical fiber free space alignment communication devices.

[0057] Thirdly, this application provides an optical fiber free space alignment communication system, the system including the optical fiber free space alignment communication device described in the first aspect, wherein the number of optical fiber free space alignment communication devices is two;

[0058] Each fiber optic free space alignment communication device completes unidirectional optical alignment with another fiber optic free space alignment communication device to achieve coaxial optical alignment between the two fiber optic free space alignment communication devices.

[0059] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method described in the second aspect.

[0060] This application provides a fiber optic free-space alignment communication device, method, system, and storage medium, including a memory, a processor, a camera at a preset fixed position, a dual-axis pan-tilt unit, and an auxiliary recognition background plate mounted on the dual-axis pan-tilt unit; a marker is set on the auxiliary recognition background plate, a beam collimating lens is set in the area of ​​the marker, and a visible light laser beam generating device is set on the side of the beam collimating lens away from another fiber optic free-space alignment communication device; the processor is interconnected with the memory, the camera, and the dual-axis pan-tilt unit circuits respectively; the memory is used to store computer programs; the camera is used to acquire data from another fiber optic free-space alignment communication device. The device includes an image of a background panel. The processor reads a computer program from the memory and performs the following operations: acquiring an image captured by a camera and identifying markers on the background panel in the image; if markers are identified in the image, determining whether a light spot is present in the image, where the light spot is formed by a visible light laser beam emitted by a visible light laser beam generator to the other fiber optic free-space alignment communication device; determining the deflection angle of the dual-axis gimbal based on the presence of a light spot, and controlling the dual-axis gimbal to deflect according to the deflection angle to achieve unidirectional optical alignment with the other fiber optic free-space alignment communication device. The camera captures an image and sends it to the processor for processing. The processor uses image recognition technology to identify markers and light spots and performs alignment judgment. Based on the identification result, it determines the gimbal deflection angle and controls the gimbal deflection. The gimbal adjusts the position of the emitted beam on the opposite background panel by adjusting the horizontal and vertical axis angles, and the background panel receives the emitted beam. This combination of software and hardware simplifies the system structure, reduces system cost and energy consumption, and facilitates operation. Attached Figure Description

[0061] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0062] Figure 1 An application scenario diagram of the fiber optic free-space alignment communication device provided in this application;

[0063] Figure 2 This is a schematic diagram of the structure of the fiber optic free space alignment communication device provided in Embodiment 1 of this application;

[0064] Figure 3 This is a schematic diagram of the structure of the fiber optic free space alignment communication device provided in Embodiment 2 of this application;

[0065] Figure 4 This is a schematic diagram of coordinate transformation for the fiber optic free-space alignment communication device provided in Embodiment 5 of this application;

[0066] Figure 5This is a schematic diagram of world coordinate system 2 provided in Embodiment 5 of this application;

[0067] Figure 6 This is a schematic diagram of the center coordinates of the marker in world coordinate system 2, provided in Embodiment 9 of this application.

[0068] Figure 7 This is a schematic diagram of determining the deflection angle of a dual-axis gimbal provided in Embodiment 9 of this application;

[0069] Figure 8 This is a schematic diagram of the structure of the fiber optic free space alignment communication device provided in Embodiment Eleven of this application;

[0070] Figure 9 This is a flowchart of the fiber optic free-space coaxial alignment communication method provided in Embodiment Twelve of this application;

[0071] Figure 10 This is a schematic diagram of the structure of the fiber optic free-space alignment communication system provided in Embodiment Thirteen of this application.

[0072] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0073] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0074] To clearly understand the technical solution of this invention, a detailed description of the prior art is provided first. In the prior art, an infrared camera at the transmitting end captures images and identifies the center of the LED beacon light of the moving unit, calculates the corresponding deflection angle, and controls the rotation of the rotating platform so that the light beam hits the angle amplifier at the receiving end. After receiving the light beam from the transmitting end, the beam is focused by the angle amplifier and reflected by the spatial light modulator, then passed through a beam splitter so that part of the beam reaches the four-quadrant detector, and the rest reaches the optical fiber at the receiving end. Utilizing the beam steering capability of the receiving end, the light spot on the four-quadrant detector is ultimately located at the center of the detector. The axis of the four-quadrant detector and the optical fiber axis are symmetrical about the plane of the beam splitter; therefore, when the light spot on the four-quadrant detector is located at the center of the detector, it indicates that the remaining light beams are also coupled into the optical fiber. Due to the reversibility of the optical path, bidirectional alignment is achieved. The prior art has a complex structure, stringent alignment conditions, and high cost and energy consumption.

[0075] Based on the shortcomings of existing technologies, the applicant of this invention has creatively discovered that by introducing computer image recognition technology and a dual-axis gimbal to replace complex optical equipment, coaxial alignment of optical fibers in free space can be achieved, simplifying the system structure, facilitating operation, and reducing costs and energy consumption. Specifically, the optical fiber free space alignment communication device can be equipped with a camera, a dual-axis gimbal, and a computing device at a fixed position. A background plate and markers are placed on the dual-axis gimbal, and a collimating lens is fixed within the marker area. A visible light laser beam generator is placed on the back of the background plate and connected to the collimating lens via an optical fiber. The visible light laser beam generator can emit a beam of light, which is formed by coupling visible light with non-visible light carrying information. This beam forms a light spot on the background plate of the optical fiber free space alignment communication device on the other side through the collimating lens. The camera at the beam emission end captures the image, and the image recognition technology of the computing device identifies the markers and light spot on the opposite background plate. The deflection angle of the dual-axis gimbal on this side is determined based on the presence of a light spot, and the gimbal is controlled to deflect accordingly to adjust the position of the light spot on the background plate, ultimately achieving unidirectional optical alignment to the optical fiber free space alignment communication device on the other side.

[0076] The following describes the application scenarios of the fiber optic free-space alignment communication device, method, system, and medium provided by this invention.

[0077] Figure 1This diagram illustrates an application scenario of the fiber optic free-space alignment communication device, method, system, and medium provided by the present invention. In a mobile communication scenario, the fiber optic free-space alignment communication system includes two fiber optic free-space alignment communication devices (hereinafter referred to as communication devices), namely communication device 1 and communication device 2. A visible light laser beam generator in communication device 1 emits a coupled beam, which forms a light spot on the background plate of communication device 2. A camera in communication device 1 captures the image, and a processor performs image recognition to identify markers and the light spot on the background plate. Based on the presence or absence of the light spot, the deflection angle of the dual-axis gimbal top of the background plate is determined and adjusted accordingly. The light spot recognition is repeated, and the above steps are repeated until the coupled beam of communication device 1 is unidirectionally aligned with communication device 2. Communication device 2 simultaneously performs the above operations, ultimately achieving optical coaxial alignment of the two communication devices. For example, when communication device 1 on the ceiling needs to transmit data to communication device 2 on the table, the camera of communication device 1 captures an image containing communication device 2, identifies the position of the marker, determines and adjusts the deflection angle of the dual-axis pan-tilt head of the background plate of communication device 1, and the visible beam generating device couples the transmission data with a visible laser beam and emits it onto the background plate of communication device 2. The camera of communication device 1 captures an image containing communication device 2, the processor identifies the light spot and determines its position, determines and adjusts the deflection angle of the dual-axis pan-tilt head of the background plate of communication device 1, and repeats the above steps until unidirectional alignment between communication device 1 and communication device 2 is achieved. At this time, the data of communication device 1 can be transmitted to communication device 2. When communication device 2 needs to exchange data with communication device 1, optical coaxial alignment between communication device 2 and communication device 1 needs to be achieved. The dual-axis pan-tilt head is fixedly connected to the background plate, and the camera, dual-axis pan-tilt head, and processor are connected via a wired connection.

[0078] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0079] Example 1

[0080] Figure 2 This is a schematic diagram of the structure of an optical fiber free-space alignment communication device provided in Embodiment 1 of this application. Figure 2As shown, the fiber optic free-space alignment communication device 100 provided in this embodiment includes: a memory 101, a processor 102, a camera 103 at a preset fixed position, a dual-axis gimbal 104, and an auxiliary recognition background plate 105 disposed on the dual-axis gimbal. A marker 106 is disposed on the auxiliary recognition background plate, a beam collimating lens 107 is disposed within the marker area, and a visible light laser beam generating device 109 is disposed on the side of the beam collimating lens facing away from another fiber optic free-space alignment communication device 108.

[0081] The processor 102 is interconnected with the memory 101, the camera 103, and the dual-axis gimbal 104 circuits.

[0082] The memory 101 is used to store computer programs. The camera 103 is used to capture images, including the background plate 110, from another fiber optic free-space alignment communication device 108. The processor 102 is used to read the computer program in the memory 101 and perform the following operations:

[0083] The image captured by the camera 103 is acquired, and the marker 111 on the background board 110 in the image is identified.

[0084] If the image is identified to include marker 111, it is determined whether the image includes a light spot, which is formed by the visible light laser beam emitted by the visible light laser beam generating device 109 to the side of another optical fiber free space aligned communication device 108.

[0085] The angle to be deflected by the dual-axis gimbal 104 is determined based on the presence or absence of light spots, and the dual-axis gimbal 104 is controlled to deflect according to the deflection angle to achieve unidirectional optical alignment with another fiber optic free space alignment communication device 108.

[0086] The camera 103 and the dual-axis gimbal 104 are fixed in a preset position. For example, the longitudinal axis of the camera can be parallel to the longitudinal axis of the dual-axis gimbal 104.

[0087] The dual-axis gimbal is an adjustable gimbal in both the longitudinal and lateral dimensions. The auxiliary backdrop is used to receive the beam of light from the opposing beam, creating a light spot. This auxiliary backdrop can be a cuboid or a cube.

[0088] Specifically, the auxiliary background plate 105 is located on the dual-axis gimbal 104. For example, it can be vertically fixed to the surface of the dual-axis gimbal 104.

[0089] In this embodiment, the marker is used to identify the beam collimating lens. The marker can be ring-shaped or circular, etc. The marker 106 can be placed within a preset area in the middle of the auxiliary identification background plate 105.

[0090] In this embodiment, the beam collimating lens is used to adjust the collimation characteristics of the fiber-emerged beam and couple the incident beam propagating in free space. The beam collimating lens 107 is disposed within the area of ​​the marker 106, and exemplaryly, it may be located at the center of the marker 106 or have a slight offset.

[0091] The visible light laser beam generating device is used to emit a visible light beam, and its visible beam characteristics can help the camera determine whether unidirectional alignment has been achieved. This visible light laser beam generating device is located on the back of the auxiliary background plate 105 and is connected to the beam collimating lens 107 via an optical fiber.

[0092] The processor, memory, camera, and dual-axis pan-tilt circuitry are connected via a wired connection.

[0093] In practical applications, the camera captures images in real time, and the processor processes these images. It identifies the image coordinates of the marker, processes the image, and determines whether the light spot is within a specified area and its coordinates. If the light spot is not identified, the dual-axis gimbal deflection angle is calculated based on the initial position of the light spot and the center coordinates of the marker. The gimbal deflection is then controlled to adjust the light spot position to near the collimating lens, achieving coarse adjustment. If the light spot is successfully identified, its position is aligned. Based on the alignment result, the coordinate deviation is determined, and a PID algorithm is used for repeated fine-tuning, continuously reducing the coordinate deviation between the light spot and the collimating lens until the light spot is finally aligned with the collimating lens, thus achieving unidirectional alignment with another fiber optic free-space alignment communication device.

[0094] In this embodiment, the fiber optic free-space alignment communication device includes a memory 101, a processor 102, a camera 103 at a preset fixed position, a dual-axis gimbal 104, and an auxiliary identification background plate 105 disposed on the dual-axis gimbal. A marker 106 is disposed on the auxiliary identification background plate, a beam collimating lens 107 is disposed within the marker area, and a visible light laser beam generating device 109 is disposed on the side of the beam collimating lens facing away from another fiber optic free-space alignment communication device 108. The processor 102 is electrically interconnected with the memory 101, the camera 103, and the dual-axis gimbal 104. The memory 101 stores a computer program. The camera 103 acquires images of the background plate 110 in the other fiber optic free-space alignment communication device 108. The processor 102 reads the computer program in the memory 101 and performs the following operations: acquiring the image acquired by the camera 103 and identifying the marker 111 on the background plate 110 in the image. If marker 111 is identified in the image, it is determined whether the image contains a light spot, which is formed by a visible light laser beam emitted by the visible light laser beam generating device 109 to the side of another fiber optic free space alignment communication device 108. Based on the presence or absence of a light spot, the deflection angle of the dual-axis gimbal 104 is determined, and the dual-axis gimbal 104 is controlled to deflect according to the deflection angle to achieve unidirectional optical alignment with the other fiber optic free space alignment communication device 108. The camera captures an image and sends it to the processor for processing. The processor uses image recognition technology to identify the marker and light spot and perform alignment judgment. Based on the recognition result, the gimbal deflection angle is determined and the gimbal deflection is controlled. The gimbal adjusts the position of the emitted beam on the opposite background plate by adjusting the horizontal and vertical axis angles, and the background plate receives the emitted beam. Because of the combination of software and hardware, the system structure is simplified, system cost and energy consumption are reduced, and operation is convenient.

[0095] Example 2

[0096] Figure 3 This is a schematic diagram of the structure of an optical fiber free space alignment communication device provided in Embodiment 2 of this application, as shown below. Figure 3 As shown, this embodiment is a further refinement based on the fiber optic free space alignment communication device provided in Embodiment 1. The visible light laser beam generating device 109 in this application embodiment includes a visible light laser 110, a fiber optic communication module 111, a fiber optic cable 112, and a beam splitter 113.

[0097] The visible light laser 110 and the optical fiber communication module 111 are connected to the beam splitter 113 via optical fiber, and the beam splitter 113 is connected to the beam collimating lens 107 via optical fiber 112.

[0098] The visible light laser 110 is used to emit visible light through optical fiber 112.

[0099] The optical fiber communication module 111 is used to transmit non-visible light carrying information through an optical fiber.

[0100] The beam splitter 113 is used to couple the visible light and the non-visible light to form a visible light laser beam, and to emit the visible light laser beam to the beam collimating lens 107 through the optical fiber 112.

[0101] Specifically, the visible light laser 110 and the optical fiber communication module 111 are respectively connected to the two branches of the beam splitter 113 via optical fiber 112, and the other end of the beam splitter 113 is connected to the beam collimating lens 107 via optical fiber 112.

[0102] The visible light laser 110 is used to transmit and emit visible light, which is used to assist in beam alignment. The fiber optic communication module is used for fiber optic communication, specifically using non-visible light to carry information. This non-visible light can be infrared light, with a specific wavelength in the 1550nm or 1310nm band. The beam splitter receives the visible and non-visible light, and couples them together to form a visible light laser beam. This visible light laser beam can be emitted through a beam collimating lens to generate a light spot, modulated with information for information transmission.

[0103] In practical applications, visible lasers can emit infrared light, while fiber optic communication modules emit non-visible light carrying data information. These are coupled into a mixed beam by a beam splitter and transmitted through an optical fiber from a beam collimating lens to the opposite fiber optic free-space alignment communication device.

[0104] In this embodiment, the visible light laser beam generating device 109 includes a visible light laser 110, an optical fiber communication module 111, an optical fiber 112, and a beam splitter 113. The visible light laser 110 and the optical fiber communication module 111 are connected to the beam splitter 113 via the optical fiber, and the beam splitter 113 is connected to the beam collimating lens 107 via the optical fiber 112. The visible light laser 110 emits visible light through the optical fiber 112. The optical fiber communication module 111 emits non-visible light carrying information through the optical fiber. The beam splitter 113 couples the visible light and the non-visible light to form a visible light laser beam, and emits the visible light laser beam to the beam collimating lens 107 via the optical fiber 112. The visible light laser emits a visible beam, facilitating observation of the alignment results. The optical fiber communication module emits a non-visible beam carrying information for information transmission. The optical fiber serves as a path for beam transmission. The beam splitter couples the visible beam and the non-visible light to form a mixed beam, facilitating data transmission. A beam collimating lens transforms the emitted scattered beam into a parallel beam to maximize light transmission.

[0105] Example 3

[0106] Based on Embodiment 1 or Embodiment 2, in the fiber optic free-space alignment communication device provided in this application, the marker is circular, and when the processor identifies the marker on the background plate in the image, it is specifically used for:

[0107] The image is then input into the Hough ring algorithm.

[0108] The Hough circle algorithm is used to identify whether the image contains a marker based on the shape of the marker.

[0109] Specifically, the Hough circle algorithm transforms a circle in a two-dimensional image space into a point in a three-dimensional parameter space determined by the circle's radius and the coordinates of its center. Therefore, any circle defined by three points on the circumference corresponds to a single point in the three-dimensional parameter space after the Hough transformation. This process is analogous to an election vote; any three points on the circumference are considered voters, and the circle defined by these three points is a candidate (hereinafter referred to as the candidate circle). The algorithm iterates through all points on the circumference, voting on the candidate circles defined by any three points. After the iteration, the circle defined by the point with the highest number of votes is the circle defined by the vast majority of points on the circumference (hereinafter referred to as the elected circle). In other words, the vast majority of points lie on the circumference of the elected circle, thus determining the selected circle.

[0110] The equation of a circle in a Cartesian coordinate system is:

[0111]

[0112] Where (a, b) is the center of the circle and r is the radius, it can also be expressed as:

[0113]

[0114] Therefore, in the 3D coordinate system composed of ABR (Aspect Ratio and Graph Ratio), a single point can uniquely identify a circle. In the Cartesian xy-coordinate system, all circles passing through a given point are mapped to a 3D curve in the ABR coordinate system. All circles passing through all non-zero pixels in the xy-coordinate system constitute many 3D curves in the ABR coordinate system. Since all points on the same circle in the xy-coordinate system have the same circle equation, they map to the same point in the ABR coordinate system. Therefore, in the ABR coordinate system, this point should have N0 intersecting curves with a total of N0 pixels. By judging the number of intersections at each point in the ABR, points exceeding a certain threshold are considered circles.

[0115] Specifically, to reduce data processing volume, the two-dimensional image is processed into grayscale, and the grayscale image is input into the Hough rings algorithm model. The input image can also be a single-channel two-dimensional pixel matrix. This is not limited. There are various ways to implement the Hough rings algorithm, and this application does not limit it.

[0116] For example, the implementation of the OpenCV Hough Circle algorithm consists of two stages, the first stage being the detection of the circle center:

[0117] Edge detection is performed on the input image. The gradient of the shape is calculated, and the circumference line is determined, where the gradient of the circumference is its normal. Gradient lines for all shapes are plotted in 2D Hough space. The larger the sum of the coordinates at a point, the more times the lines intersect at that point, and the more likely that point is the center of the circle. Non-maximum suppression is performed in the four-neighborhood of the Hough space. A threshold is set; points whose sum in the Hough space is greater than this threshold correspond to the centers of the circles.

[0118] The second stage is to calculate the radius:

[0119] Calculate the distances from a given circle's center to all circumferences. These distances contain the radii of the circles corresponding to that center. These radii are equal, and the number of such radii is significantly greater than the number of other circles with equal distances. Set two thresholds: the maximum radius and the minimum radius. Keep the distances between these two radii and sort them. Find the values ​​with identical distances and count their number. Set a threshold; if the number of identical values ​​exceeds this threshold, consider that value as the radius of the circle corresponding to that center. Repeat the above steps for each circle's center to obtain all circle radii. If the Hough Circles algorithm detects a circular marker, output the center coordinates and radius of the marker in the image coordinate system.

[0120] In this embodiment, the marker is a ring shape. When the processor identifies the marker on the background of the image, it specifically inputs the image into the Hough Rings algorithm. The Hough Rings algorithm is used to identify whether the image contains a marker based on its shape. The processor can accurately identify whether a ring-shaped marker exists in the image using the Hough Rings algorithm.

[0121] Example 4

[0122] Based on any one of Embodiments 1 to 3, in the fiber optic free-space alignment communication device provided in this application, the processor, when determining whether the image includes a light spot, is specifically used for:

[0123] The image is cropped to remove areas other than the background area.

[0124] The cropped image is binarized according to a first preset pixel brightness threshold.

[0125] The binarized image is then subjected to mean filtering.

[0126] Determine whether the image after mean filtering contains pixels with brightness values ​​greater than a second preset pixel brightness threshold.

[0127] If it is determined that the image includes pixels with brightness values ​​greater than the second preset pixel brightness threshold, then the image is determined to contain light spots. If it is determined that the image does not include pixels with brightness values ​​greater than the second preset pixel brightness threshold, then the image is determined to not contain light spots.

[0128] The first preset pixel brightness threshold refers to the pixel boundary value used when performing binarization processing on the image. Its value ranges from 0 to 255, with no specific limitation. The second preset pixel brightness threshold refers to the lowest brightness value that the center point of the light spot can reach. Its value ranges from 0 to 255, with no specific limitation. For example, it can be 220.

[0129] In this system, the background color for auxiliary recognition is dark, while the color of the marker is light. That is, the pixel value of the background color is lower than the pixel value of the marker.

[0130] Specifically, the processor acquires images captured by the camera, identifies markers in the images, and selects a rectangular area of ​​a preset size to crop other areas. This rectangular area is centered on the center of the marker. Since the single-channel value of the image background generally does not reach the second preset pixel brightness threshold, it is only possible to reach the second preset pixel brightness threshold when a light spot is received on the background. Therefore, this application uses single-channel image data for processing to reduce the amount of data processing. The single-channel image is binarized according to the first preset pixel brightness threshold. For example, pixels with pixel values ​​lower than the first preset pixel brightness threshold are set to black, and pixels with pixel values ​​higher than the first preset pixel brightness threshold are set to white. The obtained binarized image is then subjected to mean filtering to remove image noise. Specifically, during mean filtering, for each pixel, the values ​​of its neighboring pixels are obtained, the mean is calculated, and the mean is set as the value of that pixel. For the mean-filtered single-channel image, it is determined whether the value of each pixel is greater than the second preset pixel brightness threshold. If there are pixels with values ​​greater than the second preset pixel brightness threshold, it can be determined that the cropped image includes a light spot. If all pixel values ​​are less than the second preset pixel brightness threshold, then the image is determined to not contain light spots.

[0131] In this embodiment, when determining whether the image includes light spots, the processor specifically performs a cropping process on the image to remove areas other than the background area. The cropped image is binarized according to a first preset pixel brightness threshold. The binarized image is then subjected to mean filtering. It is determined whether the mean-filtered image includes pixels with brightness values ​​greater than a second preset pixel brightness threshold. If pixels with brightness values ​​greater than the second preset pixel brightness threshold are found, the image is determined to include light spots. If pixels with brightness values ​​greater than the second preset pixel brightness threshold are not found, the image is determined not to include light spots. Cropping the image effectively reduces the amount of data processing. Binarization reduces the amount of data processing while highlighting the contours of the target of interest. Mean filtering effectively suppresses noise. By determining the relationship between pixel values ​​and the second preset pixel brightness threshold, the presence of light spots in the image can be accurately identified.

[0132] Example 5

[0133] Based on Embodiment 4, in the fiber optic free-space alignment communication device provided in this application embodiment, the processor, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, is specifically used for:

[0134] If a light spot is determined to exist, determine whether the light spot is aligned with a beam collimating lens in another fiber optic free-space aligned communication device.

[0135] If it is determined that the beam collimating lens in the communication device is aligned with another fiber optic free space, then the deflection angle of the dual-axis gimbal is determined to be zero.

[0136] If it is determined that the beam collimating lens in another fiber optic free space alignment communication device is not aligned, then the coordinate deviation between the light spot and the beam collimating lens is determined, and the deflection angle of the dual-axis gimbal is determined based on the coordinate deviation.

[0137] Specifically, if a light spot is determined to exist, the pixel value of each pixel within a preset rectangular region surrounding the beam collimating lens in the mean-filtered image is calculated. The proportion of high pixel values ​​is then counted to see if it exceeds a preset proportion threshold. High pixel values ​​refer to pixel values ​​that may be generated when the beam illuminates the background. If it is determined to be greater than the preset proportion threshold, the light spot is aligned with the beam collimating lens in the other fiber optic free-space alignment communication device. If the light spot is aligned with the beam collimating lens in the other fiber optic free-space alignment communication device, the dual-axis gimbal does not deflect. If the light spot is not aligned, the image coordinates of the center of the beam collimating lens and the center point of the light spot are obtained. If the center point of the beam collimating lens is located at the center point of the marker area, the image coordinates of the center point of the beam collimating lens are the same as the image coordinates of the marker center point. If the center point of the beam collimating lens is not located at the center point of the marker area, the image coordinates of the center point of the beam collimating lens are obtained by adding an offset value to the marker center coordinates. The image coordinates of the center point of the light spot are the coordinates of the pixel with the largest pixel value among the pixels with a brightness greater than a second preset pixel threshold in the mean-filtered image. The image coordinates of the center of the beam collimating lens and the center point of the light spot are then converted into world coordinates. Calculate the coordinate deviation between the center of the collimating lens and the center of the beam spot in the world coordinate system. Combine the world coordinates and dimensions of the dual-axis gimbal, and use a PID control algorithm to determine the deflection angle of the dual-axis gimbal.

[0138] The specific methods for transforming image coordinates to world coordinates are as follows:

[0139] First, the image coordinates are converted to coordinates in World Coordinate System 1 (World Coordinate System 1: ),like Figure 4 As shown:

[0140] The center image coordinates of the marker are After offset correction with the center coordinates of the beam collimating lens The image coordinates of the center of the collimating lens of the beam are obtained as follows: From image coordinates Convert to actual world coordinates The world coordinate system has its origin at the camera center. The coordinate transformation method uses a pinhole camera model. Based on triangle similarity, we can obtain:

[0141]

[0142] Where pixel is the actual physical size of a single pixel of the camera, d is the actual distance from the center of the camera to the target plane, and f is the focal length of the camera.

[0143] Coordinates in World Coordinate System 1 Convert to World Coordinate System 2 (World Coordinate System 2:) centered on the beam collimating lens of the outgoing beam. The coordinates (m, n, d') in the equation are given. For example, ... Figure 5 As shown, the three axes of world coordinate system 2 are consistent with those of world coordinate system 1, except that the origin is moved to the center of the collimating lens of the outgoing beam. The system structure diagram is shown below. Figure 6 As shown in the figure, the coordinates (m,n,d') represent the center position of the collimating lens of the incident beam.

[0144] In this system, the relative positions of the gimbal center and the camera are fixed, and the coordinates of the gimbal center in world coordinate system 1 are: The offset position of the optical fiber relative to the center of the gimbal is Therefore, in world coordinate system 2, the coordinates of the center of the collimating lens of the incident beam are:

[0145]

[0146] Among them, the PID control algorithm is a closed-loop algorithm that combines proportional, derivative, and integral operations. It compares the difference between the actual output and the target output, then multiplies the difference, its derivative, and its integral by a coefficient, and sums these to determine the output adjustment angle. Essentially, it is a negative feedback regulation. In this application, when using the PID control algorithm to determine the deflection angle of the dual-axis gimbal, since each alignment is a discrete operation, a discrete PID algorithm is used. The formula can be expressed as:

[0147]

[0148] Where u[k] is the rotation angle, and k p k is the proportionality coefficient. T k is the integral coefficient. D Here, e[k] represents the differential coefficient, and e[k] is the difference in coordinates between the marker and the light spot during the k-th alignment process. The X-axis coordinate difference controls the rotation of the turntable in the X direction, and the Y-axis coordinate difference controls the rotation of the turntable in the Y direction. Of the three coefficients, the proportional coefficient controls the convergence speed, and the differential coefficient reduces oscillations during the alignment process. This application does not use integral coefficients because the static error of the camera when measuring the marker position in the image is relatively small.

[0149] In this embodiment, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, the processor specifically determines whether the light spot is aligned with a beam collimating lens in another fiber optic free-space alignment communication device if the presence of a light spot is confirmed. If aligned with the beam collimating lens in the other fiber optic free-space alignment communication device, the processor determines the deflection angle of the dual-axis gimbal to be zero. If not aligned with the beam collimating lens in the other fiber optic free-space alignment communication device, the processor determines the coordinate deviation between the light spot and the beam collimating lens, and determines the deflection angle of the dual-axis gimbal based on the coordinate deviation. Through the light spot alignment determination operation, the deflection angle of the dual-axis gimbal can be accurately determined.

[0150] Example 6

[0151] Based on Embodiment 5, in the fiber optic free-space alignment communication device provided in this application embodiment, the processor, when determining whether the light spot is aligned with the beam collimating lens in another fiber optic free-space alignment communication device, is specifically used for:

[0152] Determine whether the proportion of a first pixel value in the preset region surrounding the collimating lens of the beam in the mean-filtered image is greater than a preset proportion threshold, wherein the first pixel value is a pixel value greater than a first preset pixel brightness threshold.

[0153] If the value is determined to be greater than the preset percentage threshold, then the light spot is aligned with the beam collimating lens in another fiber free space alignment communication device.

[0154] If the value is less than or equal to a preset percentage threshold, then the light spot is determined to be misaligned with the beam collimating lens in another fiber free space aligned communication device.

[0155] The first pixel value refers to the high pixel value generated when the light beam shines on it.

[0156] Specifically, the coordinates of the center of the beam collimating lens are obtained. Within a preset area surrounding the beam collimating lens, it is determined whether the pixel value of each pixel is the first pixel value. The proportion of the number of pixels with the first pixel value within the preset area to the total number of pixels is counted. It is then determined whether this proportion is greater than a preset proportion threshold. If it is greater than the preset proportion threshold, it is determined that the light spot is aligned with the beam collimating lens in the other fiber free space alignment communication device. Otherwise, it is determined that the light spot is not aligned with the beam collimating lens in the other fiber free space alignment communication device.

[0157] In this embodiment, when determining whether a light spot is aligned with a beam collimating lens in another fiber optic free-space alignment communication device, the processor specifically determines whether the proportion of a first pixel value within a preset area surrounding the beam collimating lens in the mean-filtered image is greater than a preset proportion threshold. The first pixel value is a pixel value greater than a first preset pixel brightness threshold. If it is determined to be greater than the preset proportion threshold, then the light spot is determined to be aligned with the beam collimating lens in the other fiber optic free-space alignment communication device. If it is determined to be less than or equal to the preset proportion threshold, then the light spot is determined not to be aligned with the beam collimating lens in the other fiber optic free-space alignment communication device. By determining the relationship between the proportion of the first pixel value and the preset proportion threshold, it is possible to accurately determine whether the light spot is aligned with the beam collimating lens in the other fiber optic free-space alignment communication device.

[0158] Example 7

[0159] Based on Embodiment 5 or Embodiment 6, in the fiber optic free-space alignment communication device provided in this application embodiment, the processor, when determining the coordinate deviation between the light spot and the beam collimating lens, is specifically used for:

[0160] The pixel with the largest pixel value among the pixels in the image after mean filtering that are greater than the second preset pixel brightness threshold is obtained.

[0161] The coordinates of the pixel with the largest pixel value are determined as the center coordinates of the light spot in the image coordinate system.

[0162] Determine the center coordinates of the beam collimating lens in the image coordinate system.

[0163] The center coordinates of the light spot in the image coordinate system and the center coordinates of the beam collimating lens in the image coordinate system are converted into the center coordinates in the world coordinate system.

[0164] The coordinate deviation between the light spot and the collimating lens is determined based on the center coordinates of the light spot in the world coordinate system and the center coordinates of the beam collimating lens in the world coordinate system.

[0165] Specifically, the image after mean filtering is acquired. For each pixel in the image, it is determined whether the pixel value is greater than a second preset pixel brightness threshold. The pixel with the largest pixel value is selected from the set of pixels with a value greater than the second preset pixel brightness threshold. This pixel is determined as the center coordinate of the light spot in the image coordinate system. The center coordinate of the marker in the image coordinate system is acquired, and an offset is added to obtain the center coordinate of the beam collimating lens in the image coordinate system. According to the coordinate transformation method in Embodiment 5, the center coordinates of the light spot and the beam collimating lens in the image coordinate system are transformed into center coordinates in the world coordinate system, with the beam collimating lens of the outgoing beam as the origin. The difference between the center coordinates of the light spot in the world coordinate system and the center coordinates of the beam collimating lens in the world coordinate system in each direction is calculated to obtain the coordinate deviation between the light spot and the beam collimating lens.

[0166] In this embodiment, when determining the coordinate deviation between the light spot and the collimating lens, the processor specifically acquires the pixel with the largest pixel value among the pixels in the mean-filtered image that are greater than a second preset pixel brightness threshold. The coordinates of the pixel with the largest pixel value are determined as the center coordinates of the light spot in the image coordinate system. The center coordinates of the collimating lens in the image coordinate system are also determined. The center coordinates of the light spot and the collimating lens in the image coordinate system are converted into center coordinates in the world coordinate system. The coordinate deviation between the light spot and the collimating lens is determined based on the center coordinates of the light spot and the collimating lens in the world coordinate system. By acquiring the pixel with the largest pixel value among the pixels greater than the second preset pixel brightness threshold, the center coordinates of the light spot in the image coordinate system are determined. By converting the center coordinates of the light spot and the collimating lens in the image coordinate system into center coordinates in the world coordinate system, the coordinate deviation between the light spot and the collimating lens can be accurately determined.

[0167] Example 8

[0168] Based on any one of Embodiments 3 to 7, in the fiber optic free-space alignment communication device provided in this application, the processor, after recognizing that the image includes a marker, is further configured to:

[0169] The Hough circular algorithm is used to determine the first coordinates of the marker in the image coordinate system.

[0170] The first coordinates of the markers in multiple images are averaged to obtain the first mean coordinates.

[0171] The first mean coordinates are converted to coordinates in the world coordinate system to obtain the second coordinates of the marker.

[0172] The first coordinate refers to the center coordinate of the marker in the image coordinate system. The second coordinate refers to the center coordinate of the marker in the world coordinate system.

[0173] Specifically, the grayscale image is input into the Hough rings algorithm model, and the center coordinates and radius of the marker in the image coordinate system are output. Multiple frames of images are captured continuously, and a Hough transform is performed. The mean of the marker center coordinates from the obtained multiple frames is calculated; this mean coordinate is the first mean coordinate. The marker center coordinates are then converted to coordinates in the world coordinate system using a pinhole camera method. The specific method is as described in Example 5.

[0174] In this embodiment, after identifying a marker in the image, the processor further uses the Hough circle algorithm to determine the first coordinates of the marker in the image coordinate system. The first coordinates of the markers in multiple images are averaged to obtain a first average coordinate. The first average coordinate is then converted to coordinates in the world coordinate system to obtain the second coordinates of the marker. The Hough circle algorithm can determine the center coordinates of the marker in the image coordinate system. Averaging the center coordinates of the marker reduces the impact of camera shake during image capture. The coordinate transformation converts the average coordinates of the marker in the image coordinate system to coordinates in the world coordinate system.

[0175] Example 9

[0176] Based on Embodiment 8, in the fiber optic free-space alignment communication device provided in this application embodiment, the processor, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, is further configured to:

[0177] If it is determined that there is no light spot, then obtain the second coordinates of the marker.

[0178] The angle to be deflected by the dual-axis gimbal is determined based on the second coordinate of the marker and the coordinates and dimensions of the dual-axis gimbal in the world coordinate system.

[0179] The second coordinate refers to the center coordinate of the marker in the world coordinate system.

[0180] Specifically, the image coordinates of the center of the marker are obtained, and the coordinate transformation method in Example 5 is used to convert the image coordinates into coordinates in the world coordinate system, with the beam collimating lens of the outgoing beam as the origin.

[0181] like Figure 7 As shown, the coordinates of the dual-axis gimbal in the world coordinate system are (-R). x -R y The offset dimension of the beam collimating lens from the center of the dual-axis gimbal to the output beam is (R, 0). x R yThe angle to be deflected by the dual-axis gimbal is determined based on the second coordinates of the marker and the coordinates and offset dimensions of the dual-axis gimbal in the world coordinate system. For example, continuing the example in Embodiment 5, the position of the light spot is adjusted from... Change to A dual-axis gimbal needs to rotate at an angle. . and The derivation process is the same, only with Derivation process explained. The derivation process is as follows:

[0182] Because the adjustment process does not change the light spot in the Y direction. w2 The offset in the direction, so it can only be done in X. w2 -Z w2 The above derivation. (As shown in the example...) Figure 7 As shown. The equations of the straight line L containing the adjusted optical fiber and the emitted beam are:

[0183]

[0184] The straight line needs to pass through the center of the lens. Substituting the coordinates of this point into the equation for L, we obtain:

[0185]

[0186] The equation can be solved to obtain:

[0187]

[0188] in, For rotating rod and X w2 The included angle, and definition Figure 7 The situation shown Take the positive value.

[0189] Similarly, we can conclude that:

[0190]

[0191] The processor, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, is further configured to, if it is determined that no light spot exists, acquire the second coordinates of the marker. The deflection angle of the dual-axis gimbal is then determined based on the second coordinates of the marker, the coordinates of the dual-axis gimbal in the world coordinate system, and its dimensions. By using the coordinates of the marker and the dual-axis gimbal in the world coordinate system, along with the dimensions of the dual-axis gimbal, the deflection angle of the dual-axis gimbal can be determined, enabling coarse adjustment of the dual-axis gimbal.

[0192] Example 10

[0193] Based on Embodiment Nine, in the fiber optic free-space alignment communication device provided in this application embodiment, after controlling the dual-axis gimbal to deflect according to the deflection angle, the processor is further configured to:

[0194] Perform the step of determining whether the image contains light spots.

[0195] Specifically, after the dual-axis gimbal is controlled to deflect according to the deflection angle, the camera recaptures the image and performs spot recognition. If a spot is recognized, alignment is performed. If no spot is recognized, the deflection angle of the dual-axis gimbal is determined again based on the coordinates of the marker in the world coordinate system and the coordinates and dimensions of the dual-axis gimbal in the world coordinate system, and the dual-axis gimbal is controlled to deflect.

[0196] In this embodiment, after controlling the dual-axis gimbal to deflect according to the deflection angle, the processor is further configured to perform a step of determining whether the image includes a light spot. By identifying whether a light spot exists in the image, the deflection angle of the dual-axis gimbal can be determined, thereby achieving precise adjustment of the dual-axis gimbal.

[0197] Example 11

[0198] Figure 8 This is a schematic diagram of the structure of the fiber optic free-space alignment communication device provided in an embodiment of this application. Figure 8 As shown, based on any one of Embodiments 1 to 10, the fiber optic free-space alignment communication device provided in this application is configured such that the fiber optic free-space alignment communication device 110 is mounted on a transceiver terminal 111. An auxiliary identification background plate 112 is mounted on a dual-axis gimbal 113, which is positioned on the surface of the transceiver terminal 111 and on the same surface as the camera of the camera 114. The auxiliary identification background plates and cameras of both transceiver terminals face each other. The dual-axis gimbal 113 and the camera are fixed to the surface of the transceiver terminal and are both located on the same surface. The auxiliary identification background plate 112 is vertically fixed to the dual-axis gimbal 113. The auxiliary identification background plates and cameras of both transceiver terminals face each other.

[0199] In this embodiment, the fiber optic free-space alignment communication device is mounted on the transceiver terminal. An auxiliary identification background plate 112 is mounted on a dual-axis gimbal 113, which is positioned on the surface of the transceiver terminal 111 and on the same surface as the camera of the camera 114. The auxiliary identification background plates and cameras of both transceiver terminals face each other. The auxiliary identification background plate 112 receives the transmitted light beam, the camera 114 captures the image, and the processor identifies the markers and their coordinates in the image. The deflection angle of the dual-axis gimbal 113 is determined based on the initial coordinates of the light spot and the center coordinates of the marker, and the deflection of the dual-axis gimbal 113 is controlled so that the light spot falls on the background plate near the marker, achieving coarse adjustment of the dual-axis gimbal 113. The light spot is identified, and the deviation between the center coordinates of the light spot and the marker is determined. The deflection angle of the dual-axis gimbal 113 is then determined. A PID control algorithm is used to repeatedly deflect the angle of the dual-axis gimbal 113, thereby adjusting the position of the light spot formed on the auxiliary background plate 112 of the fiber optic free-space alignment communication device on the opposite side. This ensures that the light spot is ultimately aligned with the beam collimating lens, achieving unidirectional optical alignment of the fiber optic free-space alignment communication device. The auxiliary identification background plates and cameras of the two transceiver terminals are set facing each other. The same operation is performed on the fiber optic free-space alignment communication device on the other side, achieving optical coaxial alignment between the transceiver terminals and the fiber optic free-space alignment communication device.

[0200] Example 12

[0201] Figure 9 A flowchart illustrating the method of the fiber optic free-space alignment communication device provided in this application embodiment. Figure 9 As shown, the method provided in this application embodiment is applied to the fiber optic free-space alignment communication device as described in any one of Embodiments 1 to 11, and the method includes the following steps:

[0202] Step S121: Acquire the image captured by the camera and identify the markers on the background board in the image.

[0203] Step S122: If an identifier is identified in the image, determine whether the image includes a light spot, wherein the light spot is formed by a visible light laser beam emitted by a visible light laser beam generator to another optical fiber free space aligned with the communication device.

[0204] Step S123: Determine the angle to be deflected by the dual-axis gimbal based on the presence or absence of light spots, and control the dual-axis gimbal to deflect according to the deflection angle, so as to achieve unidirectional optical alignment between the two optical fiber free space alignment communication devices.

[0205] Optionally, the marker is circular, and the processor, when recognizing the marker on the background in the image, includes the following schemes:

[0206] The image is input into the Hough Circles algorithm. Using the Hough Circles algorithm, the presence or absence of a marker in the image is determined based on the shape of the marker.

[0207] Optionally, the processor, when determining whether the image includes a light spot, includes the following scheme:

[0208] The image is cropped to remove areas other than the background area. The cropped image is then binarized according to a first preset pixel brightness threshold. The binarized image is then subjected to mean filtering. It is determined whether the mean-filtered image contains pixels with brightness values ​​greater than a second preset pixel brightness threshold. If pixels with brightness values ​​greater than the second preset pixel brightness threshold are found, the image is determined to contain light spots. If pixels with brightness values ​​greater than the second preset pixel brightness threshold are not found, the image is determined to not contain light spots.

[0209] Optionally, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, the processor includes the following scheme:

[0210] If a light spot is determined to exist, it is then determined whether the light spot is aligned with the beam collimating lens in another fiber optic free-space alignment communication device. If it is determined to be aligned with the beam collimating lens in another fiber optic free-space alignment communication device, the deflection angle to be determined for the dual-axis gimbal is zero. If it is determined not to be aligned with the beam collimating lens in another fiber optic free-space alignment communication device, the coordinate deviation between the light spot and the beam collimating lens is determined, and the deflection angle to be determined for the dual-axis gimbal is determined based on the coordinate deviation.

[0211] Optionally, the processor, when determining whether the light spot is aligned with the beam collimating lens in another fiber-optic free-space aligned communication device, includes the following scheme:

[0212] The algorithm determines whether the proportion of a first pixel value within a preset region surrounding the beam collimating lens in the mean-filtered image is greater than a preset proportion threshold, where the first pixel value is a pixel value greater than a first preset pixel brightness threshold. If it is determined to be greater than the preset proportion threshold, then the light spot is determined to be aligned with the beam collimating lens in another fiber optic free-space alignment communication device. If it is determined to be less than or equal to the preset proportion threshold, then the light spot is determined not to be aligned with the beam collimating lens in another fiber optic free-space alignment communication device.

[0213] Optionally, the processor, when determining the coordinate deviation between the light spot and the beam collimating lens, includes the following scheme:

[0214] The pixel with the largest pixel value among the pixels in the mean-filtered image that are greater than a second preset pixel brightness threshold is obtained. The coordinates of the pixel with the largest pixel value are determined as the center coordinates of the light spot in the image coordinate system. The center coordinates of the beam collimating lens in the image coordinate system are determined. The center coordinates of the light spot and the center coordinates of the beam collimating lens in the image coordinate system are converted into center coordinates in the world coordinate system. The coordinate deviation between the light spot and the beam collimating lens is determined based on the center coordinates of the light spot and the center coordinates of the beam collimating lens in the world coordinate system.

[0215] Optionally, after recognizing that the image includes a marker, the processor further includes the following scheme:

[0216] The Hough circular algorithm is used to determine the first coordinates of the marker in the image coordinate system. The first coordinates of the markers in multiple images are then averaged to obtain first mean coordinates. These first mean coordinates are then converted to coordinates in the world coordinate system to obtain the second coordinates of the marker.

[0217] Optionally, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, the processor further includes the following scheme:

[0218] If it is determined that there is no light spot, then the second coordinates of the marker are obtained. Based on the second coordinates of the marker and the coordinates and dimensions of the dual-axis gimbal in the world coordinate system, the deflection angle of the dual-axis gimbal is determined.

[0219] Optionally, after controlling the dual-axis gimbal to deflect according to the deflection angle, the processor further includes the following:

[0220] Perform the step of determining whether the image contains light spots.

[0221] The fiber optic free-space coaxial alignment communication method provided in this application can be applied to the fiber optic free-space alignment communication device provided in any one of the embodiments from Embodiment 1 to Embodiment 11. The specific implementation methods and beneficial effects are similar, and will not be described in detail here.

[0222] Example 13

[0223] Figure 10 This is a schematic diagram of the fiber optic free-space aligned communication system provided in this application. Figure 10As shown, the fiber optic free-space alignment communication system includes the fiber optic free-space alignment communication device described in any one of Embodiments 1 to 12, wherein there are two fiber optic free-space alignment communication devices. Each fiber optic free-space alignment communication device performs unidirectional optical alignment with the other fiber optic free-space alignment communication device to achieve coaxial optical alignment between the two fiber optic free-space alignment communication devices.

[0224] The fiber optic free space alignment communication system includes fiber optic free space alignment communication device 131 and fiber optic free space alignment communication device 132, both of which complete unidirectional optical alignment to each other.

[0225] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0226] This application embodiment also provides a non-transitory computer-readable storage medium including instructions, such as a memory 101 including instructions, which can be executed by a processor 102 of the device 100 to complete the above method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0227] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A fiber optic free-space alignment communication device, characterized in that, include: The system includes a memory, a processor, a camera at a preset fixed position, a dual-axis gimbal, and an auxiliary recognition background plate set on the dual-axis gimbal; an identifier is set on the auxiliary recognition background plate, a beam collimating lens is set in the area of ​​the identifier, and a visible light laser beam generating device is set on the side of the beam collimating lens that is away from the other optical fiber free space and aligned with the communication device. The processor is interconnected with the memory, the camera, and the dual-axis gimbal circuit, respectively. The memory is used to store computer programs; the camera is used to capture images, including a background plate, from another fiber optic free-space alignment communication device. The processor is configured to read the computer program in the memory and perform the following operations: Acquire images captured by the camera and identify the markers on the background board in the images; If an identifier is identified in the image, it is determined whether the image contains a light spot. The light spot is formed when the visible light laser beam emitted by the visible light laser beam generating device passes through free space and is directly projected onto the auxiliary identification background plate of another fiber optic free space alignment communication device. The angle to be deflected by the dual-axis gimbal is determined based on the presence or absence of light spots, and the dual-axis gimbal is controlled to deflect according to the deflection angle to achieve unidirectional optical alignment between the two optical fiber free space alignment communication devices. The processor, after identifying that the image includes a marker, is further configured to: use the Hough circle algorithm to determine the first coordinates of the marker in the image coordinate system; perform mean-averaging processing on the first coordinates of the markers in multiple images to obtain a first mean coordinate; and convert the first mean coordinate to coordinates in the world coordinate system to obtain the second coordinates of the marker. The processor, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of a light spot, specifically performs the following: if it is determined that there is no light spot, it obtains the second coordinates of the marker; and determines the deflection angle of the dual-axis gimbal based on the second coordinates of the marker and the coordinates and dimensions of the dual-axis gimbal in the world coordinate system.

2. The fiber optic free-space alignment communication device according to claim 1, characterized in that, The visible light laser beam generating device includes: a visible light laser, an optical fiber communication module, an optical fiber, and a beam splitter; The visible light laser and the optical fiber communication module are connected to the beam splitter via optical fiber, and the beam splitter is connected to the optical path of the beam collimating lens via optical fiber. The visible light laser is used to emit visible light through an optical fiber; The optical fiber communication module is used to transmit non-visible light carrying information through an optical fiber; The beam splitter is used to couple the visible light and the non-visible light to form a visible light laser beam, and to emit the visible light laser beam to the beam collimating lens through an optical fiber.

3. The fiber optic free-space alignment communication device according to claim 1, characterized in that, The marker is circular; When the processor identifies the markers on the background panel in the image, it is specifically used for: The image is then input into the Hough ring algorithm; The Hough circle algorithm is used to identify whether the image contains a marker based on the shape of the marker.

4. The fiber optic free-space alignment communication device according to claim 1, characterized in that, The processor, when determining whether the image includes light spots, is specifically configured to: The image is cropped to remove areas other than the background area. The cropped image is binarized according to a first preset pixel brightness threshold. Perform mean filtering on the binarized image; Determine whether the mean-filtered image contains pixels with a brightness greater than a second preset pixel brightness threshold; If it is determined that the image includes pixels with brightness values ​​greater than the second preset pixel brightness threshold, then it is determined that the image includes light spots. If it is determined that pixels with brightness greater than the second preset pixel brightness threshold are not included, then it is determined that the image does not contain light spots.

5. The fiber optic free-space alignment communication device according to claim 4, characterized in that, The processor, when determining the deflection angle of the dual-axis gimbal based on the presence or absence of light spots, is also used for: If a light spot is determined to exist, determine whether the light spot is aligned with the beam collimating lens in another fiber free space aligned communication device. If it is determined that the beam collimating lens in the communication device is aligned with another fiber optic free space, then the deflection angle of the dual-axis gimbal is determined to be zero. If it is determined that the beam collimating lens in another fiber optic free space alignment communication device is not aligned, then the coordinate deviation between the light spot and the beam collimating lens is determined, and the deflection angle of the dual-axis gimbal is determined based on the coordinate deviation.

6. The fiber optic free-space alignment communication device according to claim 5, characterized in that, The processor, when determining whether the light spot is aligned with the beam collimating lens in another fiber-optic free-space aligned communication device, is specifically used for: Determine whether the proportion of the first pixel value in the preset area surrounding the collimating lens of the beam in the mean-filtered image is greater than a preset proportion threshold, wherein the first pixel value is a pixel value greater than a first preset pixel brightness threshold; If the value is determined to be greater than the preset percentage threshold, then the light spot is aligned with the beam collimating lens in another fiber free space alignment communication device. If the value is less than or equal to a preset percentage threshold, then the light spot is determined to be misaligned with the beam collimating lens in another fiber free space aligned communication device.

7. The fiber optic free-space alignment communication device according to claim 5, characterized in that, The processor, when determining the coordinate deviation between the light spot and the collimating lens, is specifically used for: The pixel with the largest pixel value among the pixels in the mean-filtered image that are greater than the second preset pixel brightness threshold is obtained. The coordinates of the pixel with the largest pixel value are determined as the center coordinates of the light spot in the image coordinate system; Determine the center coordinates of the beam collimating lens in the image coordinate system; The center coordinates of the light spot in the image coordinate system and the center coordinates of the beam collimating lens in the image coordinate system are transformed into the center coordinates in the world coordinate system. The coordinate deviation between the light spot and the collimating lens is determined based on the center coordinates of the light spot in the world coordinate system and the center coordinates of the beam collimating lens in the world coordinate system.

8. The fiber optic free-space alignment communication device according to claim 1, characterized in that, After controlling the dual-axis gimbal to deflect according to the deflection angle, the processor is further configured to: Perform the step of determining whether the image contains light spots.

9. The fiber optic free-space alignment communication device according to any one of claims 1-8, characterized in that, The fiber optic free-space alignment communication device is mounted on the transceiver terminal. The auxiliary recognition background plate is mounted on a dual-axis gimbal, which is located on the surface of the transceiver terminal and on the same surface as the camera. The auxiliary recognition background plates and cameras of the two transceiver terminals are arranged facing each other.

10. A fiber optic free-space coaxial alignment communication method, characterized in that, The method is applied to the fiber optic free-space alignment communication device as described in any one of claims 1-9, and the method includes: Acquire images captured by the camera and identify the markers on the background board in the images; If an identifier is identified in the image, it is determined whether the image contains a light spot. The light spot is formed when the visible light laser beam emitted by the visible light laser beam generating device passes through free space and is directly projected onto the auxiliary identification background plate of another fiber optic free space alignment communication device. The angle to be deflected by the dual-axis gimbal is determined based on the presence or absence of light spots, and the dual-axis gimbal is controlled to deflect according to the deflection angle to achieve unidirectional optical alignment between the two optical fiber free space alignment communication devices. The method further includes, after identifying the marker in the image, using the Hough circle algorithm to determine the first coordinates of the marker in the image coordinate system; averaging the first coordinates of the markers in multiple images to obtain a first average coordinate; and converting the first average coordinate to coordinates in the world coordinate system to obtain the second coordinates of the marker. When determining the deflection angle of the dual-axis gimbal based on the presence or absence of light spots, the method specifically includes: if it is determined that there are no light spots, then the second coordinates of the marker are obtained, and the deflection angle of the dual-axis gimbal is determined based on the second coordinates of the marker and the coordinates and dimensions of the dual-axis gimbal in the world coordinate system.

11. A fiber optic free-space alignment communication system, characterized in that, Includes the fiber optic free space alignment communication device as described in any one of claims 1-9, wherein the number of the fiber optic free space alignment communication devices is two; Each fiber optic free space alignment communication device completes unidirectional optical alignment with another fiber optic free space alignment communication device to achieve coaxial optical alignment between the two fiber optic free space alignment communication devices.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in claim 10.

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