Method, electronic device and storage medium for judging polarity of star sensor based on STK

Abstract

The present invention discloses a method, electronic device and storage medium for judging the polarity of a star sensor based on STK, the method comprising: determining the longitude and latitude of an outdoor star-gazing location and the placement orientation of the star sensor; starting the star sensor to obtain the quaternion of the star sensor's measured attitude; modeling in STK according to the longitude and latitude of the outdoor star-gazing location and the placement orientation of the star sensor to obtain a satellite attitude quaternion report; comparing the satellite attitude quaternion report with the star sensor's measured attitude quaternion to judge the polarity of the star sensor. The present invention has the advantages of simple test process, simple judgment criteria, intuitive judgment results and reduced test costs.

Description

Technical Field

[0001] The invention relates to the technical field of field stargazing test of star sensors, and in particular to a method for judging the polarity of a star sensor based on STK, electronic equipment and a storage medium. Background Art

[0002] The field stargazing test of star sensors is an important indicator in the development process of star sensors. It can generally be used to assess the correctness of the operation of the entire link (including the optical path) of the star sensor and confirm the correctness of the polarity of the star sensor.

[0003] The traditional method is to place the star sensor on the operating turntable, and obtain a series of star sensor measurement data by rotating the star sensor. The rotation direction of the star sensor body is obtained through data processing, and compared with the rotation direction of the operating turntable. If the polarity of the two or three axes of the star sensor is correct, the polarity of the star sensor is correct. However, this judgment method requires more equipment (such as an operating turntable and corresponding tooling, etc.), the test process is complicated (requires multiple rotations), and the test cost is relatively high. Summary of the invention

[0004] The purpose of the present invention is to provide a method, electronic device and storage medium for determining the polarity of a star sensor based on STK, so as to solve the problems of the existing method for determining the polarity of a star sensor, such as the complicated test process, complicated judgment criteria, non-intuitive judgment results and relatively high test cost. In order to solve the above problems, the present invention is implemented by the following technical solutions:

[0005] A method for determining the polarity of a star sensor based on STK comprises: step S1, determining the longitude and latitude of an outdoor star-gazing location and a placement orientation of the star sensor; step S2, starting the star sensor to obtain a quaternion of a star sensor measurement attitude; step S3, modeling in STK according to the longitude and latitude of the outdoor star-gazing location and the placement orientation of the star sensor to obtain a satellite attitude quaternion report; and step S4, comparing the satellite attitude quaternion report with the measurement attitude quaternion to determine the polarity of the star sensor.

[0006] Optionally, the error of the longitude and latitude of the outdoor star-watching location of the star sensor is less than or equal to 1°.

[0007] Optionally, the step S1 of determining the placement orientation of the star sensor includes: predefining the pointing directions of three axes of the star sensor, wherein the x-axis of the star sensor points to a first direction, the y-axis of the star sensor points to a second direction, and the z-axis of the star sensor points to a third direction.

[0008] When the star sensor performs an outdoor stargazing test, the pointing deviation between the x-axis of the star sensor and the first direction is no greater than 20°, the pointing deviation between the y-axis of the star sensor and the second direction is no greater than 20°, and the pointing deviation between the z-axis of the star sensor and the third direction is no greater than 20°.

[0009] Optionally, the step S3 includes: step S3.1, establishing a scene in the STK.

[0010] Step S3.2, adding a satellite to the scene. Step S3.3, setting the satellite position in the STK according to the longitude and latitude of the outdoor star-gazing location of the star sensor. Step S3.4, establishing a reference coordinate system in the STK. Step S3.5, setting the attitude of the satellite so that its satellite body coordinate system is associated with the reference coordinate system. Step S3.6, setting the simulation time, and generating the satellite attitude quaternion report.

[0011] Optionally, the star sensor measured attitude quaternion is the quaternion of the body coordinate system of the star sensor relative to the J2000 inertial system.

[0012] Optionally, step S4 includes: judging the polarity of the star sensor at each moment by using the following process:

[0013] Step S4.1: Record the satellite attitude quaternion report at a certain moment as follows: the first attitude quaternion q 0_stk , the second attitude quaternion q 1_stk , the third attitude quaternion q 2_stk and the fourth attitude quaternion q 3_stk .

[0014] At this moment, the attitude quaternion measured by the star sensor is recorded as follows: the first inertial quaternion q 0_starsensor , the second inertial quaternion q 1_starsenso , the third inertial quaternion q 2_starsenso and the fourth inertial quaternion q 3_starsenso .

[0015] Step S4.2: Subtract the satellite attitude quaternion report from the star sensor attitude quaternion using the following formula:

[0016] Δq1=q 1_starsenso ·q 0_stk +q 0_starsenso ·q 1_stk -q 3_starsenso ·q 2_stk +q 2_starsenso ·q 3_stk

[0017] Δq2=q2_starsenso ·q 0_stk +q 3_starsenso ·q 1_stk +q 0_starsenso ·q 2_stk -q 1_starsenso ·q 3_stk

[0018] Δq3=q 3_starsenso ·q 0_stk -q 2_starsenso ·q 1_stk +q 1_starsenso ·q 2_stk +q 0_starsenso ·q 3_stk

[0019] If all of |Δq1|, |Δq2| and |Δq3| are not greater than 0.2, the polarity test of the star sensor is correct; if any one of |Δq1|, |Δq2| and |Δq3| is greater than 0.2, the polarity test of the star sensor is incorrect.

[0020] On the other hand, the present invention further provides an electronic device, including a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method described above is implemented.

[0021] On the other hand, the present invention further provides a readable storage medium, characterized in that a computer program is stored in the readable storage medium, and when the computer program is executed by a processor, the method described above is implemented.

[0022] The present invention has at least one of the following advantages:

[0023] The method for judging the polarity of a star sensor based on STK provided by the present invention sets the reference coordinate system of the star sensor in STK. Under the premise of believing that STK is used as the reference, it can be intuitively seen in the STK three-dimensional view whether the placement of the star sensor (satellite is used to replace the star sensor in STK) is consistent with the expectation, which is intuitive and not prone to error. By comparing the attitude quaternion measured by the star sensor with the attitude quaternion generated by the STK report, if the two are consistent, it can be determined that the polarity of the star sensor is correct, otherwise it means that the polarity of the star sensor is wrong, and it is not necessary to determine the polarity of the star sensor by three rotations (the traditional method generally needs to configure a two-dimensional turntable or a three-dimensional turntable because it needs to rotate the star sensor, which is costly and complicated to operate). Not only is the operation simple, but the judgment method is simple and intuitive. It can be seen that the judgment by the present invention has the advantages of simple test process and reduced test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1A schematic flow chart of a method for determining the polarity of a star sensor based on STK provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is a further detailed description of a method, electronic device and storage medium for determining the polarity of a star sensor based on STK proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0026] like Figure 1 As shown, the present embodiment provides a method for determining the polarity of a star sensor based on STK, comprising: step S1, determining the longitude and latitude and placement orientation of an outdoor star-gazing location of the star sensor. Specifically, in the present embodiment, the error of the longitude and latitude of the outdoor star-gazing location of the star sensor is less than or equal to 1°.

[0027] The step S1 of determining the placement orientation of the star sensor includes: predefining the pointing directions of the three axes of the star sensor, wherein the x-axis of the star sensor points to a first direction, the y-axis of the star sensor points to a second direction, and the z-axis of the star sensor points to a third direction.

[0028] When the star sensor performs an outdoor stargazing test, the pointing deviation between the x-axis of the star sensor and the first direction is no greater than 20°, the pointing deviation between the y-axis of the star sensor and the second direction is no greater than 20°, and the pointing deviation between the z-axis of the star sensor and the third direction is no greater than 20°.

[0029] In this embodiment, Shanghai can be taken as an example as the outdoor star-watching location of the star sensor, so the longitude of Shanghai is 121° and the latitude is 31°.

[0030] For ease of understanding, the first direction mentioned above is geographical east, the second direction is geographical north, and the third direction is geographical sky.

[0031] Therefore, when the star sensor is conducting an outdoor stargazing test, the deviation between the x-axis of the star sensor and the “geographic east” direction is no more than 20°, the deviation between the y-axis of the star sensor and the “geographic north” direction is no more than 20°, and the deviation between the z-axis of the star sensor and the “geographic sky” direction is no more than 20°.

[0032] Step S2, start the star sensor, and obtain the star sensor measurement attitude quaternion. In the present embodiment, when the star sensor performs an outdoor stargazing test, the sampling time and the star sensor data are recorded, and the star sensor measurement attitude quaternion is obtained (this process is generally completed by an automated test device, which will not be repeated here).

[0033] Step S3: Modeling in STK according to the latitude and longitude of the outdoor star-gazing location and the placement orientation of the star sensor to obtain a satellite attitude quaternion report (here, the simulated "satellite" in STK is used to simulate the real star sensor).

[0034] STK (Satellite Tool Kit) is a satellite dynamics simulation and visualization software. It has been repeatedly tested and verified by aerospace engineers around the world. It has the characteristics of stable software operation, high dynamics simulation accuracy, and good visualization. It is widely used in the aerospace field and can generally be used as a benchmark for orbital and attitude dynamics.

[0035] Specifically, the step S3 includes: step S3.1, establishing a scene in the STK.

[0036] In this embodiment, a new scene is created in STK: To facilitate scene saving, it is recommended to rename it. For example, in this embodiment, for subsequent demonstration needs, the scene is named "starsensor_test". It can be understood that the scene name can also be any characters that meet the requirements, and the present invention is not limited to this.

[0037] Step S3.2: Add a satellite to the scene.

[0038] The operation method in the STK is as follows: New Object→Satellite in the toolbar, the system will automatically name it "Satellite 1" (the name can be changed by yourself, for example, when there are multiple stargazing locations, different place names can be used to represent different stargazing locations). In this embodiment, the example star sensor polarity test location is Shanghai, China, so "Satellite 1" is changed to "Shanghai".

[0039] Step S3.3, setting the satellite position in the STK according to the longitude and latitude of the outdoor star-watching location of the star sensor.

[0040] The operation method in the STK is as follows: in the orbit parameter setting of the "Basic" property ("Basic" → "Orbit"), set the following: set the coordinate system (Coord System) option to "Fixed", set the coordinate system type (CoordType) option to "Geodetic", enter 1km in the altitude (Altitude) option, set the latitude (Latitude) to 31deg, set the longitude (Longitude) to 121deg, and keep other parameters as default;

[0041] Note: When the settings are completed and you confirm the exit, a dialog box will pop up saying "Warning! This orbit intersects Earth", warning that the orbit intersects with the Earth. Simply click "ok" to ignore it.

[0042] Step S3.4: Establish a reference coordinate system in the STK.

[0043] Specifically, the operation method in the STK is as follows: insert a vector in "Shanghai" (click the shortcut icon "Vector Geometry Tool"), and create a new coordinate system (click the shortcut icon "Create New Axes..."), name it (such as "ENZ", which means "Northeast Sky"), select "Aligned and Constrained" in "Type", and set the corresponding coordinate axis direction (such as: in "Aligned Vector", set "Facility1→East" to the x-axis of "Body", and set "Facility1→North" to the y-axis of "Body").

[0044] Step S3.5: setting the attitude of the satellite so that the satellite body coordinate system is associated with the reference coordinate system.

[0045] Specifically, in the attitude parameter setting of the "Basic" property ("Basic" → "Attitude"), make the following settings: Set the attitude mode to be fixed with the coordinate system (select "Fixed inAxes" in the "Type" drop-down box in "Basic"), then select the reference coordinate system as "ENZ" in step 3.4 ("In "Reference Axes" → "shanghai" → "ENZ"), and the attitude is the default 0 attitude (the default values ​​of the three-axis attitudes are all 0, no setting is required);

[0046] Note: In "3D Graphics", display the reference coordinate system ("ENZ") and the satellite body coordinate system ("Body") designed in the previous step in "Vector". If the two coordinate systems completely overlap, it means whether the coordinate system establishment is consistent with expectations. It can also be intuitively seen whether the two coordinate system settings are consistent with the placement orientation of the star sensor polarity test.

[0047] Step S3.6, setting the simulation time and generating the satellite attitude quaternion report.

[0048] In this embodiment, the start and end time of the system simulation time are set in the STK (this time period must include the outdoor stargazing time), and a satellite (shanghai) quaternion attitude report is generated (right-click the satellite "shanghai" → "Report&Graph Manager" → "Installed Styles" → "Attitude Quaternions").

[0049] Tips: The quaternion index part generated by STK is q4, while the index part of the current general star sensor may be q0. Please pay attention to this when performing attitude quaternion comparison.

[0050] Step S4: Compare the satellite attitude quaternion report with the star sensor measured attitude quaternion to determine the polarity of the star sensor.

[0051] Note: The satellite attitude quaternion report based on stk is the quaternion of the satellite body coordinate system relative to the J2000 inertial system; the star sensor measured attitude quaternion is the quaternion of the star sensor body coordinate system relative to the J2000 inertial system. The two have the same definition and are directly comparable.

[0052] The step S4 comprises: judging the polarity of the star sensor at each moment by using the following process:

[0053] Step S4.1: Record the satellite attitude quaternion report at a certain moment as follows: the first attitude quaternion q 0_stk , the second attitude quaternion q 1_stk , the third attitude quaternion q 2_stk and the fourth attitude quaternion q 3_stk .

[0054] At this moment, the attitude quaternion measured by the star sensor is recorded as follows: the first inertial quaternion q 0_starsensor , the second inertial quaternion q 1_starsenso , the third inertial quaternion q 2_starsenso and the fourth inertial quaternion q 3_starsenso .

[0055] Step S4.2, use the following formula to make a difference between the satellite attitude quaternion report and the star sensor measured attitude quaternion: specifically, make a difference between the vector part of the STK simulation quaternion and the three-vector part of the star sensor measured quaternion.

[0056]

[0057] If all of |Δq1|, |Δq2| and |Δq3| are not greater than 0.2, the polarity test of the star sensor is correct; if any one of |Δq1|, |Δq2| and |Δq3| is greater than 0.2, the polarity test of the star sensor is incorrect.

[0058] On the other hand, this embodiment further provides an electronic device, including a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method described above is implemented.

[0059] On the other hand, this embodiment further provides a readable storage medium, characterized in that a computer program is stored in the readable storage medium, and when the computer program is executed by a processor, the method described above is implemented.

[0060] In summary, the method for judging the polarity of a star sensor based on STK provided by the present embodiment sets the reference coordinate system of the star sensor in STK. On the premise of trusting STK as the reference, it can be intuitively seen in the STK three-dimensional view whether the placement of the star sensor is consistent with the expectation, which is intuitive and not prone to error. By comparing the attitude quaternion measured by the star sensor with the satellite attitude quaternion generated by the STK report, if the two are consistent, it can be determined that the polarity of the star sensor is correct, otherwise it means that the polarity of the star sensor is wrong, and it is not necessary to determine the polarity of the star sensor through three rotations. Not only is the operation simple, but the judgment method is simple and intuitive. It can be seen that the judgment by using the present embodiment has the advantages of simple test process, simple judgment criteria, intuitive judgment results, and reduced test costs.

[0061] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0062] It should be noted that the devices and methods disclosed in the embodiments of this article can also be implemented in other ways. The device implementation described above is only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of this article. In this regard, each box in the flowchart or block diagram can represent a part of a module, program or code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system for performing a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0063] In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0064] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A method for determining the polarity of a star sensor based on STK, characterized in that: include: Step S1, determining the latitude and longitude and placement position of the star sensor outdoor stargazing location; Step S2, starting the star sensor to obtain the star sensor measurement attitude quaternion; Step S3, modeling in STK according to the latitude and longitude and placement orientation of the outdoor star-gazing location of the star sensor, and obtaining a satellite attitude quaternion report; Step S4, comparing the satellite attitude quaternion report with the star sensor measured attitude quaternion to determine the polarity of the star sensor; The step S4 comprises: The polarity of the star sensor at a certain moment is determined by the following process: Step S4.1: Record the satellite attitude quaternion report at a certain moment as follows: the first attitude quaternion q 0_stk , the second attitude quaternion q 1_stk , the third attitude quaternion q 2_stk and the fourth attitude quaternion q 3_stk ; At this moment, the attitude quaternion measured by the star sensor is recorded as follows: the first inertial quaternion q 0_starsensor , the second inertial quaternion q 1_starsenso , the third inertial quaternion q 2_starsenso and the fourth inertial quaternion q 3_starsenso ; Step S4.2: Subtract the satellite attitude quaternion report from the star sensor attitude quaternion using the following formula: Δq1=q 1_starsenso ·q 0_stk +q 0_starsenso ·q 1_stk -q 3_starsenso ·q 2_stk +q 2_starsenso ·q 3_stk Δq2=q 2_starsenso ·q 0_stk +q 3_starsenso ·q 1_stk +q 0_starsenso ·q 2_stk -q 1_starsenso ·q 3_stk Δq3=q 3_starsenso ·q 0_stk -q 2_starsenso ·q 1_stk +q 1_starsenso ·q 2_stk +q 0_starsenso ·q 3_stk If all of |Δq1|, |Δq2| and |Δq3| are not greater than 0.2, the polarity test of the star sensor is correct; if any one of |Δq1|, |Δq2| and |Δq3| is greater than 0.2, the polarity test of the star sensor is incorrect.

2. The method for determining the polarity of a star sensor based on STK according to claim 1, characterized in that: The error of the longitude and latitude of the outdoor star-watching location of the star sensor is less than or equal to 1°.

3. The method for determining the polarity of a star sensor based on STK as claimed in claim 2, characterized in that: The step S1 of determining the placement orientation of the star sensor comprises: predefining the pointing directions of the three axes of the star sensor, wherein the x-axis of the star sensor points to a first direction, the y-axis of the star sensor points to a second direction, and the z-axis of the star sensor points to a third direction; When the star sensor performs an outdoor stargazing test, the pointing deviation between the x-axis of the star sensor and the first direction is no greater than 20°, the pointing deviation between the y-axis of the star sensor and the second direction is no greater than 20°, and the pointing deviation between the z-axis of the star sensor and the third direction is no greater than 20°.

4. The method for determining the polarity of a star sensor based on STK as claimed in claim 3, characterized in that: The step S3 includes: step S3.1, establishing a scene in the STK; Step S3.2, adding a satellite to the scene; Step S3.3, setting the satellite position in the STK according to the latitude and longitude of the outdoor star-gazing location of the star sensor; Step S3.4, establishing a reference coordinate system in the STK; Step S3.5, setting the attitude of the satellite so that the satellite body coordinate system is associated with the reference coordinate system; Step S3.6, setting the simulation time and generating the satellite attitude quaternion report.

5. The method for determining the polarity of a star sensor based on STK as claimed in claim 4, characterized in that: The star sensor measurement attitude quaternion is the quaternion of the body coordinate system of the star sensor relative to the J2000 inertial system.

6. An electronic device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method according to any one of claims 1 to 5 is implemented.

7. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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