Positioning mark, identification method, system, control device and storage medium thereof

Abstract

The present application relates to the technical field of computer vision, and specifically provides a positioning mark, an identification method and system thereof, a control device and a storage medium, aiming at solving the problem of poor identification effect of the positioning mark in the prior art. To this end, the positioning mark comprises n*m ID points and 3 direction points; the 3 direction points are located at 3 vertices of a rectangular frame surrounding all the points; the ID points are distributed on n direction rays with the center of the rectangular frame as the end point, there are m ID points on each direction ray, and the included angle of any two adjacent rays is equal; and the mark surface is infrared reflective material. The positioning mark provided by the present application has strong anti-interference ability and is easy to identify to ensure the identification accuracy, and the mark surface is infrared reflective material, so that it only reflects infrared light, reducing the influence on the aesthetic feeling of the surrounding environment.

Description

Technical Field

[0001] This invention relates to the field of computer vision technology, and specifically provides a positioning marker and its recognition method, system, control device and storage medium. Background Technology

[0002] Visual tagging systems have become ubiquitous tools, providing a reference coordinate system by capturing images of pre-designed tags with a camera to estimate the relative position of the camera and the tags. Over the past few decades, various methods have emerged, each with its own advantages and limitations. Some tags are optimized to recover high-precision camera pose, while others aim to maximize detection speed or minimize the impact of occlusion on the detection process. Current tags, primarily those resembling black squares similar to QR codes, such as the common ARUCO type, are aesthetically unappealing in practical use. Furthermore, these tags, based on ordinary camera recognition, are highly susceptible to lighting conditions; excessive brightness or darkness can easily lead to recognition failure.

[0003] Accordingly, there is a need in the art for a new positioning marker and its identification method, system, control device, and storage medium to solve the above problems. Summary of the Invention

[0004] In order to overcome the above-mentioned defects, the present invention is proposed to provide a new positioning marker and its identification method, system, control device and storage medium to solve or at least partially solve the technical problem of poor positioning marker recognition effect in the prior art.

[0005] In a first aspect, the present invention provides a positioning marker comprising n×m ID points and 3 directional points; the 3 directional points are respectively located at the 3 vertices of a rectangular frame surrounding all the points; the ID points are distributed on rays in n directions with the center of the rectangular frame as the endpoint, each ray having m ID points, and the included angle between any two adjacent rays is equal.

[0006] In one technical solution of the above-mentioned positioning marker, the marker is made of infrared reflective material.

[0007] In a second aspect, the present invention provides a method for identifying a location marker, wherein the location marker is the location marker provided in the first aspect of the present invention, and the method includes:

[0008] Obtain x suspected punctuation marks, where x = 3 + n × m;

[0009] The orientation of the suspected marker composed of the suspected punctuation marks is determined based on the suspected punctuation marks;

[0010] Based on the orientation of the suspected marker, the suspected punctuation mark, and the preset marker template, determine whether the suspected marker is the positioning marker.

[0011] In one technical solution of the above-mentioned location marker identification method, the step of "determining the orientation of the suspected marker composed of the suspected markers based on the suspected markers" includes:

[0012] Calculate the distance between any two suspected punctuation marks;

[0013] Traverse all the suspected punctuation marks, select the two suspected punctuation marks with the largest distance between them and the suspected punctuation mark with the largest perpendicular distance from the line connecting the two suspected punctuation marks, and record the three selected suspected punctuation marks as suspected directional punctuation marks;

[0014] The orientation of the suspected mark is determined based on the suspected directional marker.

[0015] In one technical solution of the above-mentioned location marker recognition method, "obtaining x suspected markers" includes:

[0016] Obtain an image to be inspected, the image to be inspected comprising y points to be inspected, wherein y ≥ x;

[0017] Choose any one point to be inspected as the reference point, and select x-1 points to be inspected that are closest to the reference point;

[0018] The reference point and the x-1 points to be inspected together form the x suspected markers.

[0019] In one technical solution of the above-mentioned location marker recognition method, the method further includes:

[0020] For each suspected marker and / or each point to be inspected, perform ellipse fitting;

[0021] Obtain the coordinates and pixel values ​​of the fitted ellipse edge;

[0022] The centroid of the ellipse is determined based on the coordinates and the pixel values.

[0023] The distance between any two suspected markers and / or any two points to be inspected is calculated using the centroid.

[0024] In one technical solution of the above-mentioned location marker identification method, the step of "determining whether the suspected marker is the location marker based on the orientation of the suspected marker, the suspected marker point, and the preset marker template" includes:

[0025] Based on the orientation of the suspected marker, the suspected marker is mapped onto the preset marker template, the preset marker template including at least 3 + n × m preset punctuation marks;

[0026] For each suspected punctuation mark, determine whether the distance between the suspected punctuation mark and its nearest neighbor preset punctuation mark is greater than a preset threshold;

[0027] If there is no suspected marker whose distance to its nearest neighbor is greater than the preset threshold, then the suspected marker is determined to be the location marker.

[0028] If a suspected punctuation mark is found to be located at a distance greater than the preset threshold from its nearest neighbor, a new reference point is selected, and x-1 points to be checked that are closest to the new reference point are selected to obtain a new set of suspected punctuation marks. The process of determining whether the distance between the new suspected punctuation mark and its nearest neighbor is greater than the preset threshold is repeated until no suspected punctuation mark is found to be located at a distance greater than the preset threshold from its nearest neighbor.

[0029] In one technical solution of the above-mentioned location marker recognition method, the method further includes:

[0030] If the suspected marker is determined to be the positioning marker, the pose of the device that captured the suspected marker is determined based on the pixel coordinate information of the positioning marker in the image and the coordinate information of the positioning marker in the preset marker template.

[0031] In a third aspect, the present invention provides a location marker identification system, wherein the location marker is the location marker provided in the first aspect of the present invention, and the system includes:

[0032] A selection module, configured to acquire x suspected punctuation marks;

[0033] Analysis module, configured to determine the orientation of a suspected marker composed of the suspected punctuation marks based on the suspected punctuation marks;

[0034] The identification module is configured to determine whether the suspected mark is the positioning mark based on the orientation of the suspected mark, the suspected punctuation mark, and a preset mark template.

[0035] In a fourth aspect, a control device is provided, comprising a processor and a storage device, the storage device being adapted to store a plurality of program codes, the program codes being adapted to be loaded and run by the processor to perform the location marker recognition method described in any of the above-described technical solutions.

[0036] In a fifth aspect, a computer-readable storage medium is provided, wherein a plurality of program codes are stored therein, the program codes being adapted to be loaded and run by a processor to perform the location marker identification method described in any of the above-described technical solutions.

[0037] The above-described technical solutions of the present invention have at least one or more of the following beneficial effects:

[0038] In implementing the technical solution of this invention, the positioning marker provided by this invention includes n×m ID points and 3 direction points; the 3 direction points are respectively located at the 3 vertices of a rectangular frame surrounding all the points; the ID points are distributed on rays in n directions with the center of the rectangular frame as the endpoint, with m ID points on each ray, and the included angle between any two adjacent rays is equal; the marker surface is made of infrared reflective material. This positioning marker has strong anti-interference ability and is easy to identify to ensure its identification accuracy, and the infrared reflective material on the marker surface ensures that it only reflects infrared light, reducing the impact on the aesthetics of the surrounding environment.

[0039] In implementing the technical solution of this invention, the positioning marker identification method provided by this invention determines the orientation of a suspected marker by identifying suspected marker points, and determines whether the suspected marker is a positioning marker based on the orientation of the suspected marker, the suspected marker points, and a preset marker template. Determining the orientation based on the suspected marker points contained within it provides data with a simple and easily obtainable structure, while the preset marker template ensures the accuracy of the reference data.

[0040] Furthermore, in implementing the technical solution of this invention, the positioning marker recognition method provided by this invention performs ellipse fitting for each suspected marker and / or each point to be inspected, obtains the coordinates and pixel values ​​of the edge of the fitted ellipse, then determines the centroid of the ellipse based on the coordinates and pixel values, and uses the centroid to calculate the distance between any two suspected markers and / or any two points to be inspected. By using the centroid of the fitted ellipse as the reference point for calculating the distance between any two suspected markers and / or any two points to be inspected, instead of directly using the center of the ellipse as the reference point in the prior art, the problem of center offset caused by the floating phenomenon of the ellipse edge contour is avoided.

[0041] Furthermore, in implementing the technical solution of the present invention, the positioning marker identification method provided by the present invention determines whether the distance between the suspected marker and its nearest neighbor preset marker is greater than a preset threshold for each suspected marker. The present invention determines whether there are noise points in this group of suspected markers. If there are, the group of suspected markers is discarded and a new group of suspected markers is selected with a new reference point, thereby improving the accuracy of identification and avoiding the occurrence of inaccurate results in subsequent calculations or positioning due to mistakenly taking noise points as a marker in the positioning marker. Attached Figure Description

[0042] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Furthermore, similar numbers in the drawings are used to denote similar components, wherein:

[0043] Figure 1 This is a schematic flowchart of the main steps of a location marker identification method according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic flowchart of the main steps of a method for obtaining suspected punctuation marks according to an embodiment of the present invention;

[0045] Figure 3 This is a schematic flowchart of the main steps of a method for determining the orientation of a suspected marker according to an embodiment of the present invention;

[0046] Figure 4 This is a schematic flowchart of the main steps of a location marker identification method according to an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of a positioning mark according to an embodiment of the present invention;

[0048] Figure 6 This is a schematic diagram of a positioning mark according to another embodiment of the present invention;

[0049] Figure 7 This is a schematic diagram of the main structure of a location marker identification system according to an embodiment of the present invention.

[0050] List of reference numerals :

[0051] 11: Selection module; 12: Analysis module; 13: Recognition module. Detailed Implementation

[0052] Some embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0053] In the description of this invention, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, memory, and may also include software components, such as program code, or a combination of software and hardware. A processor can be a central processing unit, microprocessor, image processor, digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor can be implemented in software, in hardware, or a combination of both. Non-transitory computer-readable storage media includes any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "a" or "this" can also include plural forms.

[0054] Please see the appendix Figure 1 , Figure 1 This is a schematic flowchart of the main steps of a location marker identification method according to an embodiment of the present invention. The method mainly includes steps S1-S3.

[0055] Step S1: Obtain x suspected punctuation marks, x = 3 + n × m.

[0056] In this embodiment, the suspected punctuation mark is the punctuation mark to be verified, n represents the arrangement of ID punctuation marks along n directions in the actual positioning mark, m represents the specific number of ID punctuation marks arranged in each direction, and the quantity 3 represents the number of directional punctuation marks in the actual positioning mark. In specific application scenarios, there are several positioning marks pasted, and the specific positions of their internal ID punctuation marks are different (e.g., near the center or near the outer edge), making each positioning mark unique. This characteristic makes each positioning mark contain different information, but the number of directions in which ID punctuation marks are distributed and the number of marks arranged in each direction are the same for each positioning mark.

[0057] In one implementation, in conjunction with the appendix Figure 2 The diagram shows the main steps of the method for obtaining suspected punctuation marks. The method mainly includes steps S11-S13.

[0058] Step S11: Obtain the image to be inspected, which includes y points to be inspected, where y ≥ x.

[0059] Step S12: Select any point to be inspected as the reference point, and select the x-1 points to be inspected that are closest to the reference point.

[0060] Step S13: The reference point and x-1 points to be inspected form x suspected markers.

[0061] In this embodiment, the image to be inspected is generally an image captured by a camera that contains positioning markers. In real-world scenarios, noise may exist around the positioning markers due to lighting conditions. Therefore, the points to be inspected in the image include the marks of the actual positioning markers and noise from non-actual positioning markers.

[0062] Step S2: Determine the orientation of the suspected markers composed of suspected punctuation marks based on the suspected punctuation marks.

[0063] In this embodiment, the orientation of the mark can be determined based on the positional relationship and degree of deformation between suspected punctuation marks, or the orientation of the suspected mark can be determined based on special suspected punctuation marks.

[0064] In one implementation, in conjunction with the appendix Figure 3 The flowchart shown is a key step of the method for determining the orientation of a suspected marker. The method includes steps S21-S23.

[0065] Step S21: Calculate the distance between any two suspected punctuation marks.

[0066] Step S22: Traverse all suspected punctuation marks, select the two suspected punctuation marks with the largest distance between them and the suspected punctuation mark with the largest perpendicular distance from the line connecting the two suspected punctuation marks, and record the three selected suspected punctuation marks as suspected directional punctuation marks.

[0067] Step S23: Determine the orientation of the suspected marker based on the suspected directional marker.

[0068] In this embodiment, the distance between each pair of x suspected directional points is calculated. The two points with the greatest distance are the directional directional points (vertices) at the two ends of the diagonal of the rectangle in the actual positioning mark, and the point with the greatest distance from the diagonal is the third directional directional point (vertice) in the actual positioning mark. Using these three suspected directional directional points, the orientation of the suspected mark can be determined according to the principle of vector cross product.

[0069] exist Figure 2 and / or Figure 3 In the illustrated embodiment, since the punctuation marks (suspected punctuation marks and / or points to be inspected) in real-world scenarios have a certain area and their shapes may not be sufficiently precise, it is necessary to determine a reference point with reference value. The distance between reference points is the distance between the punctuation marks. In one implementation, for each suspected punctuation mark and / or each point to be inspected, ellipse fitting is performed; the coordinates and pixel values ​​of the fitted ellipse's edge are obtained; the centroid of the ellipse is determined based on the coordinates and pixel values; and the distance between any two suspected punctuation marks and / or any two points to be inspected is calculated using the centroid.

[0070] This implementation performs ellipse fitting for each suspected punctuation point and / or each point to be inspected, obtaining the coordinates and pixel values ​​of the fitted ellipse's edge. Then, the centroid of the ellipse is determined based on the coordinates and pixel values, and the distance between any two suspected punctuation points and / or any two points to be inspected is calculated using the centroid. By using the centroid of the fitted ellipse as the reference point for calculating the distance between any two suspected punctuation points and / or any two points to be inspected, instead of directly using the center of the ellipse as the reference point in existing technologies, the problem of center offset caused by the floating phenomenon of the ellipse's edge contour is avoided.

[0071] Step S3: Determine whether the suspected mark is a positioning mark based on the orientation of the suspected mark, the suspected punctuation mark, and the preset mark template.

[0072] In this embodiment, the orientation of the suspected marker can be used to perform an affine transformation, for example, mapping it onto a preset marker template to determine the degree of overlap.

[0073] In one embodiment, step S3 may further include: mapping the suspected marker onto a preset marker template based on the orientation of the suspected marker, the preset marker template including at least 3 + n × m preset markers; for each suspected marker, determining whether the distance between the suspected marker and its nearest neighbor preset marker is greater than a preset threshold; if no suspected marker is greater than the preset threshold in distance between it and its nearest neighbor preset marker, then the suspected marker is determined to be a positioning marker; if a suspected marker is greater than the preset threshold in distance between it and its nearest neighbor preset marker, then a new reference point is selected, and x-1 points to be checked that are closest to the new reference point are selected to obtain a new set of suspected markers, and the determination of whether the distance between the new suspected marker and its nearest neighbor preset marker is greater than the preset threshold is repeated until no suspected marker is greater than the preset threshold in distance between it and its nearest neighbor preset marker.

[0074] In this embodiment, by determining whether there are noise points in this group of suspected markers, if so, the group of suspected markers is discarded and a new group of suspected markers is selected with a new reference point, which improves the accuracy of identification and avoids the situation where noise points are mistakenly used as markers in the positioning marks, resulting in inaccurate results in subsequent calculations or positioning.

[0075] In another implementation, if the suspected marker is determined to be a positioning marker, the pose of the device that captured the suspected marker is determined based on the pixel coordinate information of the positioning marker in the image and the coordinate information of the positioning marker in the preset marker template. Specifically, the PnP algorithm (Perspective-n-Point) is used, etc., which is not limited here.

[0076] Please see the appendix Figure 4 , Figure 4This is a schematic flowchart illustrating the main steps of a location marker identification method according to an embodiment of the present invention. Since specific location markers are used in this embodiment, please refer to the relevant documentation first. Figure 5 and Figure 6 A schematic diagram of the positioning markers shown.

[0077] like Figure 5 The diagram shows a positioning marker, which includes three black directional markers located at the top left, bottom left, and bottom right corners, and eight gray ID markers distributed along eight directions indicated by dashed lines (dashed lines are for auxiliary viewing and do not actually exist). On each dashed line, there is also a white marker representing another placement position for the ID marker in that direction. Therefore, this type (i.e., eight directions, with two choices per direction) is... Figure 5 In addition to the styles shown, there are also 2 8 -1 style. It should be understood that the default markup template should include, for example: Figure 5 All punctuation marks shown are used to ensure that various styles of marks of the same type can be effectively detected. Furthermore, each punctuation mark can be assigned a unique code on the preset mark template. For example, in binary, punctuation marks closer to the ray endpoint can be marked as 0, while those farther from the ray endpoint can be marked as 1. Figure 5 The ID punctuation in the location marker shown can be encoded as 01001011, starting from the top and proceeding clockwise.

[0078] like Figure 6 The diagram shows a positioning marker consisting of three black directional markers located at the top left, bottom left, and bottom right corners, and eight gray ID markers distributed along four directions indicated by dashed lines (these are auxiliary lines and do not actually exist). On each dashed line, there is also a white marker representing another placement position for the ID marker in that direction. Therefore, this type (i.e., four directions, with two out of three options per direction) is... Figure 6 In addition to the styles shown, there are also 3 4 -1 style. It should be understood that the default markup template should include, for example: Figure 6 All punctuation marks shown are used to ensure that various styles of marks of the same type can be effectively detected. Furthermore, each punctuation mark can be assigned a unique code on the preset mark template. For example, in binary, the punctuation mark closest to the ray endpoint can be marked as 00, the punctuation mark furthest from the ray endpoint as 10, and the punctuation mark in the middle as 01. Thus, the code of the ID punctuation mark in the positioning mark shown in Figure 6, starting from the top and proceeding clockwise from the inside out, can be described as 00 / 01 / 00 / 10 / 01 / 10 / 00 / 10.

[0079] The above Figure 5 and Figure 6 The styles of the positioning marks shown are only two of the positioning marks provided by this invention and are not intended to limit this invention.

[0080] For example Figure 4 In the illustrated embodiment, combined with Figure 5 The location marker identification method of the present invention, as shown in the diagram, can be described as follows:

[0081] First, detect the dots in the image: perform edge detection first, and then perform ellipse fitting to obtain the center of the dots. Since the center obtained by edge detection is not accurate enough due to binarization and has fluctuations, the centroid method is used to obtain a more accurate center of the ellipse dot.

[0082] Then, punctuation detection is performed: Assuming k points are detected in an image, any one of these points is selected, and its 10 nearest neighbors are found, forming a set of 11 points. Within this set of 11 points, pairwise distances are calculated to find the two vertices of the bounding box, i.e., the two points furthest apart. Figure 5 The two red dots (top left and bottom right) are used to determine the direction of the marker. Due to the limited field of view, there won't be a large angle of view for the marker. The two points with the greatest distance are the two points on the diagonal of the square marker. These two points form a straight line, and the point with the greatest distance to this line is the third defense point (bottom left red dot). This detects the three directional marker points of the square marker's vertices. Using the vector cross product principle, the marker's orientation is determined. Since three points are sufficient to calculate the affine transformation from one plane to another, the marker is mapped to a 700x700 reference marker. The remaining eight points are also mapped to the reference marker. If any of these 11 points differs from the reference marker's position by 10 pixels after mapping, that 11 points are considered not to be the desired marker, but a false positive (noise).

[0083] During the noise detection process, if any one of these 11 points is more than the distance of the corresponding point in the template than the threshold T, the group of points is considered invalid and contains noise. Another point is then selected and its 10 nearest neighbors are selected to form a new group of points.

[0084] Finally, the number of each marker is determined in the reference marker, and the PnP solution is performed using the 3D coordinate information of the marker in the template and the pixel coordinate information in the image to calculate the pose of the camera relative to the marker.

[0085] The steps of the location marker identification method provided by the present invention have now been described. It should be noted that although the steps are described in a specific order in the above embodiments, those skilled in the art will understand that, in order to achieve the effects of the present invention, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders, and these variations are all within the protection scope of the present invention.

[0086] Furthermore, the present invention also provides a location marker recognition system.

[0087] See appendix Figure 7 , Figure 7 This is a main structural block diagram of a location marker identification system according to an embodiment of the present invention. Figure 7 As shown, the location marker identification system in this embodiment of the invention mainly includes a selection module 11, an analysis module 12, and an identification module 13. In some embodiments, one or more of the selection module 11, analysis module 12, and identification module 13 can be combined into a single module. In some embodiments, the selection module 11 can be configured to acquire x suspected markers. The analysis module 12 can be configured to determine the orientation of a suspected marker composed of suspected markers based on the suspected markers. The identification module 13 can be configured to determine whether a suspected marker is a location marker based on the orientation of the suspected marker, the suspected markers, and a preset marker template.

[0088] The aforementioned location marker recognition system is used for execution Figure 1 The location marker identification method embodiments shown are similar in technical principle, the technical problems solved and the technical effects produced. Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the location marker identification system can be referred to the content described in the embodiments of the location marker identification method, which will not be repeated here.

[0089] Those skilled in the art will understand that all or part of the processes in the method of the above embodiment of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable storage medium can include any entity or device capable of carrying the computer program code, a medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory, a random access memory, an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer-readable storage medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable storage medium does not include electrical carrier signals and telecommunication signals.

[0090] Furthermore, the present invention also provides a control device. In one embodiment of the control device according to the present invention, the control device includes a processor and a storage device. The storage device can be configured to store a program for executing the location marker identification method of the above-described method embodiments, and the processor can be configured to execute the program in the storage device. The program includes, but is not limited to, a program for executing the location marker identification method of the above-described method embodiments. For ease of explanation, only the parts related to the embodiments of the present invention are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of the present invention. This control device can be a control device device comprising various electronic devices.

[0091] Furthermore, the present invention also provides a computer-readable storage medium. In one embodiment of the computer-readable storage medium according to the present invention, the computer-readable storage medium can be configured to store a program that performs the location marker identification method of the above-described method embodiments. This program can be loaded and run by a processor to implement the above-described location marker identification method. For ease of explanation, only the parts related to the embodiments of the present invention are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of the present invention. The computer-readable storage medium can be a storage device comprising various electronic devices. Optionally, in the embodiments of the present invention, the computer-readable storage medium is a non-transitory computer-readable storage medium.

[0092] Furthermore, it should be understood that since the various modules are only provided to illustrate the functional units of the device of the present invention, the physical devices corresponding to these modules may be the processor itself, or a part of the processor's software, hardware, or a combination of software and hardware. Therefore, the number of modules shown in the figures is merely illustrative.

[0093] Those skilled in the art will understand that the various modules in the device can be adaptively split or combined. Such splitting or combining of specific modules will not cause the technical solution to deviate from the principles of the present invention; therefore, the technical solutions after splitting or combining will fall within the protection scope of the present invention.

[0094] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for identifying location markers, characterized in that, The positioning markers include n×m ID marks and 3 direction marks; the 3 direction marks are located at the 3 vertices of the rectangle surrounding all the marks; the ID marks are distributed on n rays with the center of the rectangle as the endpoint, and there are m ID marks on each ray, and the included angle between any two adjacent rays is equal. The method includes: Obtain x suspected punctuation marks, where x = 3 + n × m; The orientation of the suspected marker composed of the suspected punctuation marks is determined based on the suspected punctuation marks; Based on the orientation of the suspected marker, the suspected punctuation mark, and the preset marker template, determine whether the suspected marker is the positioning marker; The step of determining the orientation of the suspected marker composed of the suspected punctuation marks based on the suspected punctuation marks includes: calculating the distance between any two suspected punctuation marks; traversing all suspected punctuation marks, selecting the two suspected punctuation marks with the largest distance between them and the suspected punctuation mark with the largest perpendicular distance from the line connecting the two suspected punctuation marks, and recording the three selected suspected punctuation marks as suspected direction punctuation marks; and determining the orientation of the suspected marker based on the suspected direction punctuation marks. The step of determining whether a suspected marker is the location marker based on the orientation of the suspected marker, the suspected punctuation mark, and the preset marker template includes: mapping the suspected marker onto the preset marker template based on the orientation of the suspected marker, the preset marker template including at least 3 + n × m preset punctuation marks; for each suspected punctuation mark, determining whether the distance between the suspected punctuation mark and its nearest neighbor preset punctuation mark is greater than a preset threshold; if there is no suspected punctuation mark whose distance to its nearest neighbor preset punctuation mark is greater than the preset threshold, then the suspected marker is determined to be the location marker.

2. The method as described in claim 1, characterized in that, The acquisition of x suspected punctuation marks includes: Obtain an image to be inspected, the image to be inspected comprising y points to be inspected, wherein y ≥ x; Choose any one point to be inspected as the reference point, and select x-1 points to be inspected that are closest to the reference point; The reference point and the x-1 points to be inspected together form the x suspected markers.

3. The method according to any one of claims 1-2, characterized in that, The method further includes: For each suspected punctuation mark and / or each point to be inspected, perform ellipse fitting; Obtain the coordinates and pixel values ​​of the fitted ellipse edge; The centroid of the ellipse is determined based on the coordinates and the pixel values. The distance between any two suspected markers and / or any two points to be inspected is calculated using the centroid.

4. The method as described in claim 2, characterized in that, The method further includes: If a suspected punctuation mark is found to be located at a distance greater than the preset threshold from its nearest neighbor, a new reference point is selected, and x-1 points to be checked that are closest to the new reference point are selected to obtain a new set of suspected punctuation marks. The process of determining whether the distance between the new suspected punctuation mark and its nearest neighbor is greater than the preset threshold is repeated until no suspected punctuation mark is found to be located at a distance greater than the preset threshold from its nearest neighbor.

5. The method as described in claim 1, characterized in that, The method further includes: If the suspected marker is determined to be the positioning marker, the pose of the device that captured the suspected marker is determined based on the pixel coordinate information of the positioning marker in the image and the coordinate information of the positioning marker in the preset marker template.

6. The method as described in claim 1, characterized in that, The markings are made of infrared reflective material.

7. A location marker identification system, characterized in that, The positioning markers include n×m ID marks and 3 direction marks; the 3 direction marks are located at the 3 vertices of the rectangle surrounding all the marks; the ID marks are distributed on n rays with the center of the rectangle as the endpoint, and there are m ID marks on each ray, and the included angle between any two adjacent rays is equal. The system includes: A selection module, configured to acquire x suspected punctuation marks; An analysis module is configured to determine the orientation of a suspected marker composed of the suspected punctuation marks based on the suspected punctuation marks. The determination of the orientation of the suspected marker based on the suspected punctuation marks includes: calculating the distance between any two suspected punctuation marks; traversing all suspected punctuation marks, selecting the two suspected punctuation marks with the largest mutual distance and the suspected punctuation mark with the largest perpendicular distance from the line connecting the two suspected punctuation marks, and recording the three selected suspected punctuation marks as suspected direction punctuation marks; and determining the orientation of the suspected marker based on the suspected direction punctuation marks. The identification module is configured to determine whether a suspected marker is the location marker based on the orientation of the suspected marker, the suspected punctuation mark, and a preset marker template. The determination includes: mapping the suspected marker onto the preset marker template based on its orientation, the preset marker template including at least 3 + n × m preset punctuation marks; for each suspected punctuation mark, determining whether the distance between the suspected punctuation mark and its nearest neighbor preset punctuation mark is greater than a preset threshold; if no suspected punctuation mark has a distance greater than the preset threshold between it and its nearest neighbor preset punctuation mark, then the suspected marker is determined to be the location marker.

8. A control device, comprising a processor and a storage device, said storage device being adapted to store a plurality of program codes, characterized in that, The program code is adapted to be loaded and run by the processor to perform the location marker identification method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a plurality of program codes, characterized in that, The program code is adapted to be loaded and run by a processor to perform the location marker identification method according to any one of claims 1 to 6.

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