Star map identification method and system

Abstract

The invention relates to a star map recognition method, which comprises the following steps of: uniformly partitioning a celestial sphere, mapping fixed stars in a star catalogue to corresponding celestial sphere partitions, and completing star catalogue partitioning; constructing a navigation feature library by taking the partitioned star catalogue as a basic unit; and retrieving all star angular distances in the set # imgabs1 # in a basic unit # imgabs0 # of the navigation feature library one by one, and voting # imgabs2 # according to a retrieval result to complete star map recognition. The invention further relates to a star map recognition system. According to the invention, the image quality and the anti-noise performance can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to a star map recognition method and system. Background Art

[0002] A star sensor is a high-precision, high-reliability autonomous attitude measurement instrument that uses stars as its measurement objects. It has been widely used in space payloads such as spacecraft.

[0003] When the star sensor just enters the working state or the attitude is lost, the star sensor needs to image the starry sky, and then complete the attitude measurement after star point extraction, centroid positioning and star map recognition. Its main working principle is: use the optical system and image sensor to image the starry sky, and obtain the position and brightness information of the star point on the target surface of the image sensor through star point extraction and centroid positioning. Then, the star point is identified through the star map to find the corresponding matching navigation star in the star catalog, and finally the attitude of the star sensor relative to the inertial coordinate system is measured according to the recognition result.

[0004] With the rapid development of aerospace technology, the maneuverability of spacecraft is increasing day by day, and the demand for high-attitude update rate and high-precision star sensors is urgent. Since star map recognition is the most complex and time-consuming link in the working process of star sensors, higher requirements are currently placed on the recognition speed and recognition rate of star map recognition algorithms.

[0005] In addition, as the space environment becomes increasingly complex, in order to achieve real-time and accurate early warning of various non-cooperative targets, the requirements for the detection sensitivity of star sensors are constantly increasing, resulting in a sharp increase in the number of high-magnitude navigation stars in the star catalog, seriously affecting the recognition speed and recognition rate of star map recognition.

[0006] Therefore, star map recognition algorithms with fast recognition speed and high recognition rate are important key technologies in the current research field of star sensors. Summary of the invention

[0007] In view of this, it is necessary to provide a star map recognition method and system, which can improve the recognition speed and recognition rate of star map recognition.

[0008] The present invention provides a star map recognition method, which comprises the following steps: S1, evenly partitioning the celestial sphere, mapping the stars in the star catalog to the corresponding celestial sphere partitions, and completing the star catalog partitions; S2, building a navigation feature library based on the star catalog that has completed the partitions; S3, Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the Voting is conducted to complete the star map identification.

[0009] Preferably, the step S1 comprises: is the celestial coordinate system, the center of the celestial sphere The line connecting the three vertices of any face of the regular icosahedron forms a cone. The cone intersects with the celestial sphere, dividing the entire celestial sphere into 20 regions, which are numbered ;for Each area in the The entire celestial sphere is evenly divided into partitions; among them, The theoretical value range is , determined according to the field of view size of the star sensor; In determining the parameters Finally, map the stars in the star catalog to the corresponding celestial surface partitions to complete the star catalog partitioning.

[0010] Preferably, the step S2 comprises: Arrange the basic units of the navigation feature library in ascending order and divide them into The block index function in formula (1) is established to retrieve the position of the star angle distance in the basic unit of the navigation feature library: (1) In the formula, Indicates rounding to the nearest direction. and Respectively represent the minimum and maximum values ​​of the star angle distance in the basic unit of the navigation feature library, Represents the star angle distance The block number where it is located, its value range is .

[0011] Preferably, the step S3 comprises: Assume that there is Star points, the stars are composed of The star angle distance constitutes a set , in the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the To vote, here’s how: (2) In formula (2), Represents the basic unit of the navigation feature library The voting score, represent star point and The star angle distance between Represents the basic unit of the navigation feature library Middle Star and The star angle distance between is the error threshold; As shown in formula (2), if the basic unit of the navigation feature library There are two stars in and , so that the star angle distance With star points and Star angle distance At the error threshold The range is equal, indicating that the star and With star points and Matching, navigation feature library basic unit Voting score Increase; on the contrary, the basic unit of navigation feature library The voting score remains unchanged.

[0012] Preferably, the step S3 further comprises: Because of the collection The number of angular distances between the central stars is , so theoretically the basic unit of the navigation feature library The highest vote score is ,Right now ; If there are pseudo-stars in the field of view, that is, when the basic unit of the navigation feature library in formula (2) The voting score meets When the star angle distance of at least two sets of characteristic triangles in the star map belongs to the basic unit of the navigation feature library , then the basic unit of the navigation feature library is considered With star angle distance collection Matching is successful, that is, the star angle distance set It is the basic unit of navigation feature library Subset; then continue to use the basic unit of the navigation feature library Complete the identification of other star points in the star map; If you have traversed the collection All the star angle distances in the navigation feature library are Voting score , then the basic unit of the navigation feature library is considered With star angle distance collection If the match is unsuccessful, replace the navigation feature library base unit and re-vote it.

[0013] The present invention also provides a star map recognition system, which includes a partition module, a construction module, and a voting module, wherein: The partitioning module is used to evenly partition the celestial surface, map the stars in the star catalog to the corresponding celestial surface partitions, and complete the star catalog partitioning; The construction module is used to construct a navigation feature library based on the star catalog that has completed the partitioning; The voting module is used to Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the Voting is conducted to complete the star map identification.

[0014] Preferably, the partition module is specifically used for: is the celestial coordinate system, the center of the celestial sphere The line connecting the three vertices of any face of the regular icosahedron forms a cone. The cone intersects with the celestial sphere, dividing the entire celestial sphere into 20 regions, which are numbered ;for Each area in the The entire celestial sphere is evenly divided into partitions; among them, The theoretical value range is , determined according to the field of view size of the star sensor; In determining the parameters Finally, map the stars in the star catalog to the corresponding celestial surface partitions to complete the star catalog partitioning.

[0015] Preferably, the building blocks are specifically used for: Arrange the basic units of the navigation feature library in ascending order and divide them into The block index function in formula (1) is established to retrieve the position of the star angle distance in the basic unit of the navigation feature library: (1) In the formula, Indicates rounding to the nearest direction. and Respectively represent the minimum and maximum values ​​of the star angle distance in the basic unit of the navigation feature library, Represents the star angle distance The block number where it is located, its value range is .

[0016] Preferably, the voting module is specifically used for: Assume that there is Star points, the stars are composed of The star angle distance constitutes a set , in the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the To vote, here’s how: (2) In formula (2), Represents the basic unit of the navigation feature library The voting score, represent star point and The star angle distance between Represents the basic unit of the navigation feature library Middle Star and The star angle distance between is the error threshold; As shown in formula (2), if the basic unit of the navigation feature library There are two stars in and , so that the star angle distance With star points and Star angle distance At the error threshold The range is equal, indicating that the star and With star points and Matching, navigation feature library basic unit Voting score Increase; on the contrary, the basic unit of navigation feature library The voting score remains unchanged.

[0017] Preferably, the voting module is also specifically used for: Because of the collection The number of angular distances between the central stars is , so theoretically the basic unit of the navigation feature library The highest vote score is ,Right now ; If there are pseudo-stars in the field of view, that is, when the basic unit of the navigation feature library in formula (2) The voting score meets When the star angle distance of at least two sets of characteristic triangles in the star map belongs to the basic unit of the navigation feature library , then the basic unit of the navigation feature library is considered With star angle distance collection Matching is successful, that is, the star angle distance set It is the basic unit of navigation feature library Subset; then continue to use the basic unit of the navigation feature library Complete the identification of other star points in the star map; If you have traversed the collection All the star angle distances in the navigation feature library are Voting score , then the basic unit of the navigation feature library is considered With star angle distance collection If the match is unsuccessful, replace the navigation feature library base unit and re-vote it.

[0018] The capacity of the navigation feature library constructed by this application is significantly reduced based on basic unit voting, and the retrieval range of the navigation feature library is greatly narrowed during the star map recognition process, which not only significantly improves the recognition speed, but also effectively reduces the probability of redundant matching and mismatching. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of the star map recognition method of the present invention; Figure 2 A schematic diagram of uniformly partitioning the celestial surface provided by an embodiment of the present invention; Figure 3 A schematic diagram of a basic unit of a navigation feature library provided by an embodiment of the present invention; Figure 4 FIG. 4 is a hardware architecture diagram of the star map recognition system of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the invention clearer, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the invention and do not constitute a limitation to the invention. Similar components in different embodiments use associated similar component numbers. In the following embodiments, many detailed descriptions are to enable the invention to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other components, materials, and methods. In some cases, some operations related to the invention are not shown or described in the specification, in order to avoid the core part of the invention being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0021] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to form various implementation methods. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary sequence, unless otherwise specified that a certain sequence must be followed.

[0022] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0023] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0024] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0025] See also Figure 1 , which is a flow chart of a preferred embodiment of the star map recognition method of the present invention.

[0026] Step S1, evenly partition the celestial surface, map the stars in the star catalog to the corresponding celestial surface partitions, and complete the star catalog partitioning. Specifically: Please also read Figure 2 , is the celestial coordinate system, the center of the celestial sphere The line connecting the three vertices of any face of the regular icosahedron forms a cone. The cone intersects with the celestial sphere, dividing the entire celestial sphere into 20 regions, which are numbered .for Each area in the The entire celestial sphere is evenly divided into partitions; among them, The theoretical value range is In practical applications, it is necessary to select an appropriate value based on the field of view of the star sensor. Finally, map the stars in the star catalog to the corresponding celestial surface partitions to complete the star catalog partitioning.

[0027] Step S2, constructing a navigation feature library based on the partitioned star catalog as the basic unit, that is, simplifying the whole celestial sphere star map recognition problem into several local celestial sphere star map recognition problems. Specifically: Please also read Figure 3 , the red dotted circle line represents the field of view of the star sensor, and the appropriate star catalog partition parameters are selected , so that the field of view angle corresponding to the spherical surface partition after the star catalog partition includes the field of view of the star sensor. Figure 3 It can be seen from the figure that, with partition catalog 0 as the center, the 13 partition catalogs in the neighborhood must contain all the stars in the field of view of the star sensor. Figure 3 By building a navigation feature library based on the 13 partition star catalogs in the celestial sphere as basic units, the problem of identifying the entire celestial sphere star map can be simplified into several local celestial sphere star map recognition problems, which reduces the data volume of the navigation feature library and further reduces the number of feature matching times.

[0028] Since the arrangement order of the star angle distances in the basic unit of the navigation feature library is relatively chaotic, it is difficult to achieve fast retrieval in the process of star map recognition. Therefore, in order to improve the retrieval speed of the star angle distances in the basic unit of the navigation feature library, this embodiment arranges the basic unit of the navigation feature library in ascending order and divides it into The block index function in formula (1) is established, and the position of the star angle distance in the basic unit of the navigation feature library is retrieved through this function.

[0029] (1) In the formula, Indicates rounding to the nearest direction. and Respectively represent the minimum and maximum values ​​of the star angle distance in the basic unit of the navigation feature library, Represents the star angle distance The block number where it is located, its value range is .

[0030] Step S3, in the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the Voting is conducted to complete the star map identification. Specifically: Assume that there is Star points, the stars are composed of The star angle distance constitutes a set In the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the To vote, here’s how: (2) In the formula, Represents the basic unit of the navigation feature library The voting score, represent star point and The star angle distance between Represents the basic unit of the navigation feature library Middle Star and The star angle distance between is the error threshold.

[0031] As shown in formula (2), if the basic unit of the navigation feature library There are two stars in and , so that the star angle distance With star points and Star angle distance At the error threshold The range is equal, indicating that the star and With star points and Matching, navigation feature library basic unit Voting score Increase; on the contrary, the basic unit of navigation feature library The voting score remains unchanged.

[0032] Because of the collection The number of angular distances between the central stars is , so theoretically the basic unit of the navigation feature library The highest vote score is ,Right now Considering that there may be pseudo-stars in the field of view, when the basic unit of the navigation feature library in formula (2) The voting score meets When the star angle distance of at least two sets of characteristic triangles in the star map belongs to the basic unit of the navigation feature library , then the basic unit of the navigation feature library is considered With star angle distance collection Matching is successful, that is, the star angle distance set It is the basic unit of navigation feature library Subset; then continue to use the basic unit of the navigation feature library Complete the identification of other star points in the star map.

[0033] However, if you have already traversed the collection All the star angle distances in the navigation feature library are Voting score At this time, there may be star angles in the star map without characteristic triangles, which belong to the basic unit of the navigation feature library. In the case of With star angle distance collection If the match is unsuccessful, replace the navigation feature library base unit and re-vote it.

[0034] See also Figure 4 , which is a hardware architecture diagram of the star map recognition system 10 of the present invention. The system includes: a partition module 101, a construction module 102, and a voting module 103. Among them: The partitioning module 101 is used to evenly partition the celestial surface, map the stars in the star catalog to the corresponding celestial surface partitions, and complete the star catalog partitioning. Specifically: Please also read Figure 2 , is the celestial coordinate system, the center of the celestial sphere The line connecting the three vertices of any face of the regular icosahedron forms a cone, and the cone intersects with the celestial surface. The partitioning module 101 divides the entire celestial surface into 20 regions, which are numbered .for For each region in the partition module 101, the partition module 101 further divides it evenly into The entire celestial sphere is evenly divided into partitions; among them, The theoretical value range is In practical applications, it is necessary to select a suitable value according to the field of view of the star sensor. Finally, map the stars in the star catalog to the corresponding celestial surface partitions to complete the star catalog partitioning.

[0035] The construction module 102 is used to construct a navigation feature library based on the partitioned star catalog, that is, to simplify the whole celestial sphere star map recognition problem into several local celestial sphere star map recognition problems. Specifically: Please also read Figure 3 , the red dotted circle line represents the field of view of the star sensor, and the appropriate star catalog partition parameters are selected , so that the field of view angle corresponding to the spherical surface partition after the star catalog partition includes the field of view of the star sensor. Figure 3 It can be seen from FIG. 1 that, with partition star catalog 0 as the center, the 13 partition star catalogs in the neighborhood must contain all the stars in the field of view of the star sensor. Therefore, the construction module 102 is based on Figure 3 By building a navigation feature library based on the 13 partition star catalogs in the celestial sphere as basic units, the problem of identifying the entire celestial sphere star map can be simplified into several local celestial sphere star map recognition problems, which reduces the data volume of the navigation feature library and further reduces the number of feature matching times.

[0036] Since the arrangement order of the star angle distances in the constructed navigation feature library basic unit is relatively chaotic, it is difficult to achieve fast retrieval in the process of star map recognition. Therefore, in order to improve the retrieval speed of the star angle distances in the navigation feature library basic unit, the construction module 102 arranges the navigation feature library basic unit in ascending order and divides it into The block index function in formula (1) is established, and the position of the star angle distance in the basic unit of the navigation feature library is retrieved through this function.

[0037] (1) In the formula, Indicates rounding to the nearest direction. and Respectively represent the minimum and maximum values ​​of the star angle distance in the basic unit of the navigation feature library, Represents the star angle distance The block number where it is located, its value range is .

[0038] The voting module 103 is used to Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the Voting is conducted to complete the star map identification. Specifically: Assume that there is Star points, the stars are composed of The star angle distance constitutes a set In the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the To vote, here’s how: (2) In the formula, Represents the basic unit of the navigation feature library The voting score, represent star point and The star angle distance between Represents the basic unit of the navigation feature library Middle Star and The star angle distance between is the error threshold.

[0039] As shown in formula (2), if the basic unit of the navigation feature library There are two stars in and , so that the star angle distance With star points and Star angle distance At the error threshold The range is equal, indicating that the star and With star points and Matching, navigation feature library basic unit Voting score Increase; on the contrary, the basic unit of navigation feature library The voting score remains unchanged.

[0040] Because of the collection The number of angular distances between the central stars is , so theoretically the basic unit of the navigation feature library The highest vote score is ,Right now Considering that there may be pseudo-stars in the field of view, when the basic unit of the navigation feature library in formula (2) The voting score meets When the star angle distance of at least two sets of characteristic triangles in the star map belongs to the basic unit of the navigation feature library , then the basic unit of the navigation feature library is considered With star angle distance collection Matching is successful, that is, the star angle distance set It is the basic unit of navigation feature library Subset; then continue to use the basic unit of the navigation feature library Complete the identification of other star points in the star map.

[0041] However, if you have already traversed the collection All the star angle distances in the navigation feature library are Voting score At this time, there may be star angles in the star map without characteristic triangles, which belong to the basic unit of the navigation feature library. In the case of With star angle distance collection If the match is unsuccessful, replace the navigation feature library base unit and re-vote it.

[0042] Although the present invention has been described with reference to the current preferred embodiments, those skilled in the art should understand that the above-mentioned preferred embodiments are only used to illustrate the present invention and are not used to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A star map recognition method, characterized in that: The method comprises the following steps: S1, evenly partition the celestial surface, map the stars in the star catalog to the corresponding celestial surface partitions, and complete the star catalog partitioning; S2, using the partitioned star catalog as the basic unit, constructs a navigation feature library; S3, in the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the Voting is conducted to complete the star map identification.

2. The star map recognition method according to claim 1, characterized in that: The step S1 comprises: is the celestial coordinate system, the center of the celestial sphere The line connecting the three vertices of any face of the regular icosahedron forms a cone. The cone intersects with the celestial sphere, dividing the entire celestial sphere into 20 regions, which are numbered ;for Each region in the The entire celestial sphere is evenly divided into partitions; among them, The theoretical value range is , determined according to the field of view size of the star sensor; In determining the parameters Finally, map the stars in the star catalog to the corresponding celestial surface partitions to complete the star catalog partitioning.

3. The star map recognition method according to claim 2, characterized in that: The step S2 comprises: Arrange the basic units of the navigation feature library in ascending order and divide them into The block index function in formula (1) is established to retrieve the position of the star angle distance in the basic unit of the navigation feature library: （1） In the formula, Indicates rounding to the nearest direction. and Respectively represent the minimum and maximum values ​​of the star angle distance in the basic unit of the navigation feature library, Represents the star angle distance The block number where it is located, its value range is .

4. The star map recognition method according to claim 3, characterized in that: The step S3 comprises: Assume that there is Star points, the stars are composed of The star angle distance constitutes a set , in the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the To vote, here’s how: （2） In formula (2), Represents the basic unit of the navigation feature library The voting score, represent star point and The star angle distance between Represents the basic unit of the navigation feature library Middle Star and The star angle distance between is the error threshold; As shown in formula (2), if the basic unit of the navigation feature library There are two stars in and , so that the star angle distance With star points and Star angle distance At the error threshold The range is equal, indicating that the star and With star points and Matching, navigation feature library basic unit Voting score Increase; on the contrary, the basic unit of navigation feature library The voting score remains unchanged.

5. The star map recognition method according to claim 4, characterized in that: The step S3 further comprises: Because of the collection The number of angular distances between the central stars is , so theoretically the basic unit of the navigation feature library The highest vote score is ,Right now ; If there are pseudo-stars in the field of view, that is, when the basic unit of the navigation feature library in formula (2) The voting score meets When the star angle distance of at least two sets of characteristic triangles in the star map belongs to the basic unit of the navigation feature library , then the basic unit of the navigation feature library is considered With star angle distance collection Matching is successful, that is, the star angle distance set It is the basic unit of navigation feature library Subset; then continue to use the basic unit of the navigation feature library Complete the identification of other star points in the star map; If you have traversed the collection All the star angle distances in the navigation feature library are Voting score , then the basic unit of the navigation feature library is considered With star angle distance collection If the match is unsuccessful, replace the navigation feature library base unit and re-vote it.

6. A star map recognition system, characterized in that: The system includes a partitioning module, a building module, and a voting module, wherein: The partitioning module is used to evenly partition the celestial surface, map the stars in the star catalog to the corresponding celestial surface partitions, and complete the star catalog partitioning; The construction module is used to construct a navigation feature library based on the star catalog that has completed the partitioning; The voting module is used to Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the Voting is conducted to complete the star map identification.

7. The star map recognition system according to claim 6, characterized in that: The partition module is specifically used for: is the celestial coordinate system, the center of the celestial sphere The line connecting the three vertices of any face of the regular icosahedron forms a cone. The cone intersects with the celestial sphere, dividing the entire celestial sphere into 20 regions, which are numbered ;for Each region in the The entire celestial sphere is evenly divided into partitions; among them, The theoretical value range is , determined according to the field of view size of the star sensor; In determining the parameters Finally, map the stars in the star catalog to the corresponding celestial surface partitions to complete the star catalog partitioning.

8. The star map recognition system according to claim 7, characterized in that: The building blocks are specifically used for: Arrange the basic units of the navigation feature library in ascending order and divide them into The block index function in formula (1) is established to retrieve the position of the star angle distance in the basic unit of the navigation feature library: （1） In the formula, Indicates rounding to the nearest direction. and Respectively represent the minimum and maximum values ​​of the star angle distance in the basic unit of the navigation feature library, Represents the star angle distance The block number where it is located, its value range is .

9. The star map recognition system according to claim 8, characterized in that: The voting module is specifically used for: Assume that there is Star points, the stars are composed of The star angle distance constitutes a set , in the navigation feature library basic unit Middle pair set All the star angle distances in are searched one by one, and the search results are sorted according to the To vote, here’s how: （2） In formula (2), Represents the basic unit of the navigation feature library The voting score, represent star point and The star angle distance between Represents the basic unit of the navigation feature library Middle Star and The star angle distance between is the error threshold; As shown in formula (2), if the basic unit of the navigation feature library There are two stars in and , so that the star angle distance With star points and Star angle distance At the error threshold The range is equal, indicating that the star and With star points and Matching, navigation feature library basic unit Voting score Increase; on the contrary, the basic unit of navigation feature library The voting score remains unchanged.

10. The star map recognition system according to claim 9, characterized in that: The voting module is also specifically used for: Because of the collection The number of angular distances between the central stars is , so theoretically the basic unit of the navigation feature library The highest vote score is ,Right now ; If there are pseudo-stars in the field of view, that is, when the basic unit of the navigation feature library in formula (2) The voting score meets When the star angle distance of at least two sets of characteristic triangles in the star map belongs to the basic unit of the navigation feature library , then the basic unit of the navigation feature library is considered With star angle distance collection Matching is successful, that is, the star angle distance set It is the basic unit of navigation feature library Subset; then continue to use the basic unit of the navigation feature library Complete the identification of other star points in the star map; If you have traversed the collection All the star angle distances in the navigation feature library are Voting score , then the basic unit of the navigation feature library is considered With star angle distance collection If the match is unsuccessful, replace the navigation feature library base unit and re-vote it.

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