Load attitude determination method and device based on angle monitoring star sensor

Abstract

The present application relates to the technical field of spacecraft attitude control, and particularly relates to a load attitude determination method and device based on an included angle monitoring star sensor, wherein the method comprises: obtaining angle conversion relationships between a reference mirror coordinate system and a star sensor measurement coordinate system, between a central prism coordinate system and the reference mirror coordinate system, and between the central prism coordinate system and a star sensor monitoring coordinate system in a ground phase; obtaining angle conversion relationships between the central prism coordinate system and the star sensor monitoring coordinate system, and between the star sensor measurement coordinate system and a J2000 coordinate system in an on-orbit phase; and combining a corresponding relationship between the star sensor measurement coordinate system and the star sensor monitoring coordinate system to determine an angle conversion relationship between the central prism coordinate system and the J2000 coordinate system in the on-orbit phase. The present application can obtain high-precision load pointing.

Description

Technical Field

[0001] This invention relates to the field of spacecraft attitude control technology, and in particular to a method and apparatus for determining the attitude of a payload based on a star sensor for monitoring the included angle. Background Technology

[0002] Satellite systems typically consist of a platform and a payload. Star sensors determine the platform's orientation, and this, combined with the installation relationship, determines the payload's orientation. However, this method does not account for interference caused by structural changes between the star sensor and the payload in space. As spacecraft performance increases, the high-precision attitude-determining star sensor and payload in satellite systems often have large structural dimensions. The uncertainty introduced by deformation due to these large structures has gradually exceeded the measurement accuracy of the attitude-determining star sensor, thus affecting the attitude-determining accuracy of the payload. Summary of the Invention

[0003] To obtain high-precision load pointing, embodiments of the present invention provide a load attitude determination method and apparatus based on a star sensor for angle monitoring.

[0004] In a first aspect, embodiments of the present invention provide a method for determining the attitude of a payload based on a star sensor monitoring the included angle.

[0005] The following system will be used for implementation;

[0006] The system includes a star sensor and a central prism; a reference mirror is provided on one side of the star sensor; the central prism is located on the payload of the spacecraft and includes two reflective surfaces with a fixed angle, which are used to reflect the two angled beams emitted by the star sensor respectively.

[0007] The method includes the following steps:

[0008] The angular transformation relationships between the reference mirror coordinate system and the star sensor measurement coordinate system, the central prism coordinate system and the reference mirror coordinate system, and the central prism coordinate system and the star sensor monitoring coordinate system are obtained during the on-site phase. Specifically, the star sensor measurement coordinate system is established with a set point as the origin, the optical axis of the star sensor as the z-axis, and the plane where the imaging chip is located as the xy-plane. The reference mirror coordinate system is established with a fixed point on the reference mirror as the origin, and its three axes are designed to be the same as those of the star sensor measurement coordinate system. The central prism coordinate system is established with a fixed point on the central prism as the origin, and its three axes are designed to be the same as those of the star sensor measurement coordinate system. The star sensor monitoring coordinate system is established with a set point as the origin, the optical axis of the star sensor as the z-axis, the line connecting the theoretical image positions of the two vertical reflecting beams as the x-axis, and the y-axis determined according to the right-hand rule.

[0009] Obtain the angular transformation relationships between the central prism coordinate system and the star sensor monitoring coordinate system during the on-orbit phase, as well as between the star sensor measurement coordinate system and the J2000 coordinate system;

[0010] By combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system, the angle transformation relationship between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is determined.

[0011] Optionally, obtaining the angular transformation relationships between the reference mirror coordinate system and the star sensor measurement coordinate system, between the central prism coordinate system and the reference mirror coordinate system, and between the central prism coordinate system and the star sensor monitoring coordinate system in the local phase includes:

[0012] Determine the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-unit development phase. The attitude transformation matrix is ​​used to represent the three-axis angle transformation relationship from one coordinate system to another; determining the attitude transformation matrix... The method involves calibrating the reference mirror coordinate system and the star sensor measurement coordinate system at room temperature during the single-machine development phase, and recording the product temperature T. 基准 ;

[0013] Determine the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT phase. Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准 Under these conditions, the coordinate system of the central prism and the coordinate system of the reference mirror are calibrated using a theodolite;

[0014] Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT phase. Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准 Under the condition of [condition], the coordinate system of the central prism is calibrated by using the angle monitoring function of the star sensor; the angle monitoring function of the star sensor is achieved by the star sensor emitting two beams to the two reflecting surfaces of the central prism and acquiring the return images.

[0015] Optionally, obtaining the angular transformation relationships between the central prism coordinate system and the star sensor monitoring coordinate system, and between the star sensor measurement coordinate system and the J2000 coordinate system during the on-orbit phase, includes:

[0016] Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the on-orbit phase. Among them, the attitude transformation matrix is ​​determined. The method involves using the angle monitoring function of the star sensor to calibrate the coordinate system of the central prism during the on-orbit phase.

[0017] Determine the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system during the on-orbit phase. Among them, the attitude transformation matrix is ​​determined. The method involves calibrating the star imagery function of the star sensor during the on-orbit phase; the star imagery function of the star sensor is achieved by acquiring star images through the star sensor.

[0018] Optionally, determining the angle transformation relationship between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase, by combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system, includes:

[0019] Based on the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-machine development phase And the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT phase. The attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT phase is determined by the following expression:

[0020] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT and on-orbit phases. and The attitude transformation matrix for the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase is determined by the following expression:

[0021] Based on the attitude transformation matrix of the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase Combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system The attitude transformation matrix for the star sensor measurement coordinate system from the AIT phase to the on-orbit phase is determined by the following expression:

[0022]

[0023] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT phase And the attitude transformation matrix of the star sensor measurement coordinate system from the AIT phase to the on-orbit phase. Determine the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase; the expression is:

[0024] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase And the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system. The attitude transformation matrix between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is determined by the following expression:

[0025] Optionally, the payload is a camera.

[0026] Optionally, the star sensor is a high-precision attitude-determining star sensor.

[0027] Secondly, embodiments of the present invention also provide a payload attitude determination device based on an angle-monitoring star sensor, applied to the following system, the system including a star sensor and a central prism; a reference mirror is provided on one side of the star sensor; the central prism is located on the payload of the spacecraft, the central prism including two reflecting surfaces with a fixed angle, used to reflect the two angled beams emitted by the star sensor respectively;

[0028] The device includes:

[0029] The local information acquisition module is used to acquire the angle transformation relationships between the reference mirror coordinate system and the star sensor measurement coordinate system, the central prism coordinate system and the reference mirror coordinate system, and the central prism coordinate system and the star sensor monitoring coordinate system during the local phase. The star sensor measurement coordinate system is established with a set point as the origin, the optical axis of the star sensor as the z-axis, and the plane where the imaging chip is located as the xy-plane. The reference mirror coordinate system is established with a fixed point on the reference mirror as the origin, and its three axes are designed to be the same as those of the star sensor measurement coordinate system. The central prism coordinate system is established with a fixed point on the central prism as the origin, and its three axes are designed to be the same as those of the star sensor measurement coordinate system. The star sensor monitoring coordinate system is established with a set point as the origin, the optical axis of the star sensor as the z-axis, the line connecting the theoretical image positions of the two vertical reflecting beams as the x-axis, and the y-axis determined according to the right-hand rule.

[0030] The on-orbit information acquisition module is used to acquire the angle transformation relationship between the central prism coordinate system and the star sensor monitoring coordinate system, as well as between the star sensor measurement coordinate system and the J2000 coordinate system during the on-orbit phase.

[0031] The load pointing determination module is used to determine the angle transformation relationship between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase by combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system.

[0032] Optionally, the local information acquisition module is used to perform the following operations:

[0033] Determine the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-unit development phase. The attitude transformation matrix is ​​used to represent the three-axis angle transformation relationship from one coordinate system to another; determining the attitude transformation matrix... The method involves calibrating the reference mirror coordinate system and the star sensor measurement coordinate system at room temperature during the single-machine development phase, and recording the product temperature T. 基准 ;

[0034] Determine the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT phase. Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准 Under these conditions, the coordinate system of the central prism and the coordinate system of the reference mirror are calibrated using a theodolite;

[0035] Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT phase. Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准 Under the condition of [condition], the coordinate system of the central prism is calibrated by using the angle monitoring function of the star sensor; the angle monitoring function of the star sensor is achieved by the star sensor emitting two beams to the two reflecting surfaces of the central prism and acquiring the return images.

[0036] Optionally, the on-orbit information acquisition module is used to perform the following operations:

[0037] Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the on-orbit phase. Among them, the attitude transformation matrix is ​​determined. The method involves using the angle monitoring function of the star sensor to calibrate the coordinate system of the central prism during the on-orbit phase.

[0038] Determine the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system during the on-orbit phase. Among them, the attitude transformation matrix is ​​determined. The method involves calibrating the star imagery function of the star sensor during the on-orbit phase; the star imagery function of the star sensor is achieved by acquiring star images through the star sensor.

[0039] Optionally, the load pointing determination module is used to perform the following operations:

[0040] Based on the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-machine development phase And the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT phase. The attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT phase is determined by the following expression:

[0041] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT and on-orbit phases. and The attitude transformation matrix for the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase is determined by the following expression:

[0042] Based on the attitude transformation matrix of the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase Combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system The attitude transformation matrix for the star sensor measurement coordinate system from the AIT phase to the on-orbit phase is determined by the following expression:

[0043]

[0044] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT phase And the attitude transformation matrix of the star sensor measurement coordinate system from the AIT phase to the on-orbit phase. Determine the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase; the expression is:

[0045] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase And the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system. The attitude transformation matrix between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is determined by the following expression:

[0046] This invention provides a method and apparatus for determining the attitude of a payload based on a star sensor with an angle monitoring capability. This method can unify the benchmark measurement data obtained from measurements under different time and space conditions, thereby obtaining a high-precision payload orientation. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart of a payload attitude determination method based on an angle-monitoring star sensor provided in an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of the system structure provided in an embodiment of the present invention;

[0050] Figure 3 This is a hardware architecture diagram of an electronic device provided in an embodiment of the present invention;

[0051] Figure 4 This is a structural diagram of a payload attitude determination device based on an angle monitoring star sensor provided in an embodiment of the present invention;

[0052] In the diagram: 200: star sensor; 201: reference mirror; 300: central prism. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0054] As mentioned earlier, with the increasing performance of spacecraft, the high-precision attitude-determining star sensors in satellite systems typically have a large structural dimension between them and the payload. The uncertainty error introduced by the deformation caused by the large structure has gradually exceeded the measurement accuracy of the attitude-determining star sensors.

[0055] To obtain high-precision payload pointing, spacecraft (such as satellites) can set a highly stable central prism on the payload and use it as a payload reference. Based on the principle of self-collimation, they can use a star sensor to emit two beams with a certain angle between them, obtain the echo of the central prism, and calculate the angle change between the payload and the central prism.

[0056] However, since the star sensor angle monitoring measures the angle change between the star sensor monitoring coordinate system and the central prism coordinate system, and the spacecraft calibrates the relationship between the star sensor reference mirror coordinate system and the central prism coordinate system during the AIT phase (Assembly, Integration and Test), the former is a relative quantity that is a time variable, while the latter is an absolute quantity. Therefore, it is necessary to design a load attitude determination method based on the star sensor angle monitoring to solve the problem that the calibration of different coordinate systems is distributed at different locations and times, and the reference is not uniform, so as to finally obtain a high-precision load pointing.

[0057] The following describes the specific implementation of the above concept.

[0058] Please refer to Figure 1 This invention provides a method for determining the attitude of a payload based on a star sensor with a specific angle of inclination, implemented using the following system: Figure 2 As shown, the system includes a star sensor and a central prism; a reference mirror is provided on one side of the star sensor; the central prism is located on the payload of the spacecraft, and the central prism includes two reflective surfaces with a fixed angle, which are used to reflect the two angled beams emitted by the star sensor respectively;

[0059] The method includes the following steps:

[0060] Step 100: Obtain the angle transformation relationships between the reference mirror coordinate system and the star sensor measurement coordinate system, between the central prism coordinate system and the reference mirror coordinate system, and between the central prism coordinate system and the star sensor monitoring coordinate system during the on-site phase.

[0061] The star sensor measurement coordinate system is a coordinate system established with a set point as the origin, the optical axis of the star sensor as the z-axis, and the plane where the imaging chip of the star sensor is located as the xy plane; the specific direction of the x-axis is unrestricted; the specific position of the origin can be set according to actual needs.

[0062] The reference mirror coordinate system is a coordinate system established with a fixed point on the reference mirror as the origin. In design, it has the same three-axis direction as the star sensor measurement coordinate system. The specific position of the origin of the reference mirror coordinate system can be set according to actual needs. In design, the three-axis direction of the reference mirror coordinate system coincides with that of the star sensor measurement coordinate system. In reality, due to assembly errors, there will be a small angular deviation between the three axes of the reference mirror coordinate system and the three axes of the star sensor measurement coordinate system.

[0063] The central prism coordinate system is a coordinate system established with a fixed point of the central prism as the origin. In design, it is the same as the three-axis direction of the star sensor measurement coordinate system. The specific position of the origin of the central prism coordinate system can be set according to actual needs. In design, the central prism coordinate system and the star sensor measurement coordinate system are basically coincident. In reality, due to factors such as assembly, gravity, and heat, there are small angular differences between the three axes of the central prism coordinate system and the three axes of the star sensor measurement coordinate system.

[0064] The star sensor monitoring coordinate system is a coordinate system with a set point as the origin, the optical axis of the star sensor as the z-axis, the line connecting the theoretical image positions of the two vertical reflective beams as the x-axis, and the y-axis determined according to the right-hand rule. The theoretical image positions of the two vertical reflective beams are the theoretical image positions of the two beams when the two beams emitted by the star sensor have an angle and are perpendicular to the reflective surface corresponding to the central prism. The specific position of the origin can be set according to actual needs.

[0065] Step 102: Obtain the angular transformation relationships between the central prism coordinate system and the star sensor monitoring coordinate system during the on-orbit phase, as well as between the star sensor measurement coordinate system and the J2000 coordinate system; the J2000 coordinate system is the geocentric inertial coordinate system.

[0066] Step 104: Combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system, determine the angle transformation relationship between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase, and obtain the payload orientation of the spacecraft during the on-orbit phase.

[0067] In this embodiment of the invention, the angle transformation relationship between relevant coordinate systems at different stages is obtained. Utilizing the correspondence between the star sensor measurement coordinate system (unaffected by launch) and the star sensor monitoring coordinate system, the angle transformation relationship between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is determined, thereby obtaining high-precision payload pointing of the spacecraft during the on-orbit phase. This invention uses the central prism as a reference to unify the reference measurement data obtained from various time and space conditions, enabling the use of angle data from star sensors with angle monitoring capabilities within the system. It should be noted that in the above embodiment, the x, y, and z axes are manually selected coordinate axes, and they can be interchanged. For example, the star sensor measurement coordinate system can also be represented as a coordinate system established with the star sensor's optical axis as the x-axis and the imaging chip's plane as the yz plane. Correspondingly, the three-axis representation of other coordinate systems can be adjusted according to the star sensor measurement coordinate system.

[0068] The following description Figure 1 The execution method for each step is shown.

[0069] First, for step 100, it further includes:

[0070] Step 100-0: Determine the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-machine development phase.

[0071] The attitude transformation matrix is ​​used to represent the three-axis angle transformation relationship from one coordinate system to another, i.e., without considering the change of the origin position; determining the attitude transformation matrix... The method involves calibrating the reference mirror coordinate system and the star sensor measurement coordinate system at room temperature during the single-machine development phase, and recording the product temperature T. 基准 ;

[0072] Using attitude transformation matrix This enables the transformation from the reference mirror coordinate system to the star sensor measurement coordinate system. The attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system needs to be calibrated using the reference mirror 201 and the star sensor 200. The specific steps can be found in existing technologies and will not be elaborated further here.

[0073] Step 100-2: Determine the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT stage.

[0074] Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准 Under these conditions, the coordinate system of the central prism and the coordinate system of the reference mirror are calibrated using a theodolite;

[0075] The coordinate systems of the central prism and the reference mirror are calibrated using a theodolite. Specifically, the coordinate system of the reference mirror is measured first using the theodolite, and then the coordinate system of the central prism is measured using the theodolite. Based on the theodolite measurement results, the attitude transformation matrix is ​​calculated. The specific steps can be found in existing technologies, and will not be elaborated further here.

[0076] Step 100-4: Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT phase.

[0077] Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准 Under these conditions, the coordinate system of the central prism is calibrated using the angle monitoring function of the star sensor;

[0078] The angle monitoring function of the star sensor is achieved by the star sensor emitting two beams to the two reflecting surfaces of the central prism and acquiring the returned images.

[0079] The two beams emitted by the star sensor 200 are reflected back to the theoretical position of the image plane by the central prism 300. Affected by factors such as assembly / adjustment / gravity / structure, the relative attitude of the star sensor 200 and the central prism 300 changes, and the reflected image also changes accordingly. By calculating the change in the reflected image, the angle change between the star sensor 200 and the central prism 300 can be determined, that is, the angle change between the star sensor monitoring coordinate system and the central prism coordinate system, thus realizing the angle monitoring function.

[0080] By using the above embodiments, the correspondence between relevant coordinate systems can be obtained through calibration before launching the spacecraft.

[0081] Then, for step 102, it further includes:

[0082] Step 102-0: Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the on-orbit phase.

[0083] Among them, the attitude transformation matrix is ​​determined. The method involves using the angle monitoring function of the star sensor to calibrate the coordinate system of the central prism during the on-orbit phase.

[0084] Step 102-2: Determine the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system during the on-orbit phase.

[0085] Among them, the attitude transformation matrix is ​​determined. The method involves calibrating the star imaging function of the star sensor during the on-orbit phase.

[0086] The star sensor's star imaging function is achieved by acquiring images of the starry sky through the star sensor. Using stars as a reference source for attitude measurement, the star sensor can output the vector direction of the star in the star sensor's measurement coordinates, providing high-precision measurement data for spacecraft attitude control and astronomical navigation.

[0087] Using the above embodiments, the correspondence between relevant coordinate systems can be obtained through measurement after the spacecraft is launched. During the spacecraft's on-orbit phase, due to potential changes in relative positional relationships, the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system is a relative quantity that is a time-varying variable.

[0088] Finally, for step 104, the following is further included:

[0089] Step 104-0: Based on the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-machine development stage. And the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT phase. The attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT phase is determined by the following expression:

[0090] Step 104-2: Based on the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT and on-orbit phases. and The attitude transformation matrix for the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase is determined by the following expression: The superscript T indicates transpose;

[0091] Step 104-4: Based on the attitude transformation matrix of the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase. Combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system The attitude transformation matrix for the star sensor measurement coordinate system from the AIT phase to the on-orbit phase is determined by the following expression:

[0092] in, This represents the attitude transformation matrix between the star sensor measurement coordinate system and the star sensor monitoring coordinate system during the AIT phase. This represents the attitude transformation matrix between the star sensor monitoring coordinate system and the star sensor measurement coordinate system during the on-orbit phase, and the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system. for The transpose of , therefore we have

[0093] Step 104-6: Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT stage. And the attitude transformation matrix of the star sensor measurement coordinate system from the AIT phase to the on-orbit phase. The attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase is determined by the following expression:

[0094] Step 104-8: Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase. And the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system. The attitude transformation matrix between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is determined by the following expression:

[0095] Using the above embodiments, the attitude transformation matrix between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is obtained through coordinate transformation. This allows for the determination of the precise orientation of the payload containing the central prism, and consequently, the spacecraft's attitude. The attitude transformation matrix between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase can be updated as needed.

[0096] Optionally, the payload is a camera that can be used to photograph the starry sky.

[0097] Optionally, the star sensor is a high-precision attitude-determining star sensor, which can achieve higher measurement accuracy.

[0098] like Figure 3 , Figure 4 As shown, this embodiment of the invention provides a payload attitude determination device based on a star sensor for angle monitoring. The device embodiment can be implemented through software, hardware, or a combination of both. From a hardware perspective, such as... Figure 3 The diagram shown is a hardware architecture diagram of an electronic device for determining the attitude of a payload based on a star sensor with an included angle, provided in an embodiment of the present invention. (Except for...) Figure 3 In addition to the processor, memory, network interface, and non-volatile memory shown, the electronic device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 4 As shown, a device in a logical sense is formed by the CPU of its electronic device reading the corresponding computer program from the non-volatile memory into memory and running it. This embodiment provides a payload attitude determination device based on an angle-monitoring star sensor, applied to the following system: the system includes a star sensor and a central prism; a reference mirror is provided on one side of the star sensor; the central prism is located on the payload of the spacecraft, and the central prism includes two reflecting surfaces at a fixed angle, used to reflect the two angled beams emitted by the star sensor respectively;

[0099] The device includes:

[0100] The local information acquisition module 401 is used to acquire the angle transformation relationships between the reference mirror coordinate system and the star sensor measurement coordinate system, the central prism coordinate system and the reference mirror coordinate system, and the central prism coordinate system and the star sensor monitoring coordinate system during the local phase. The star sensor measurement coordinate system is established with a set point as the origin, the optical axis of the star sensor as the z-axis, and the plane where the imaging chip is located as the xy-plane. The reference mirror coordinate system is established with a fixed point on the reference mirror as the origin, and its three axes are designed to be the same as those of the star sensor measurement coordinate system. The central prism coordinate system is established with a fixed point on the central prism as the origin, and its three axes are designed to be the same as those of the star sensor measurement coordinate system. The star sensor monitoring coordinate system is established with a set point as the origin, the optical axis of the star sensor as the z-axis, the line connecting the theoretical image positions of the two vertical reflecting beams as the x-axis, and the y-axis determined according to the right-hand rule.

[0101] The on-orbit information acquisition module 402 is used to acquire the angle transformation relationship between the central prism coordinate system and the star sensor monitoring coordinate system, as well as between the star sensor measurement coordinate system and the J2000 coordinate system during the on-orbit phase.

[0102] The load pointing determination module 403 is used to determine the angle transformation relationship between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase by combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system.

[0103] In this embodiment of the invention, the on-ground information acquisition module 401 can be used to execute step 100 in the above method embodiment, the on-orbit information acquisition module 402 can be used to execute step 102 in the above method embodiment, and the load pointing determination module 403 can be used to execute step 104 in the above method embodiment.

[0104] Optionally, the local information acquisition module 401 is configured to perform the following operations:

[0105] Determine the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-unit development phase. The attitude transformation matrix is ​​used to represent the three-axis angle transformation relationship from one coordinate system to another; determining the attitude transformation matrix... The method involves calibrating the reference mirror coordinate system and the star sensor measurement coordinate system at room temperature during the single-machine development phase, and recording the product temperature T. 基准 ;

[0106] Determine the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT phase. Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准Under these conditions, the coordinate system of the central prism and the coordinate system of the reference mirror are calibrated using a theodolite;

[0107] Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT phase. Among them, the attitude transformation matrix is ​​determined. The method is that the AIT stage is held at an ambient temperature of T. 基准 Under the condition of [condition], the coordinate system of the central prism is calibrated by using the angle monitoring function of the star sensor; the angle monitoring function of the star sensor is achieved by the star sensor emitting two beams to the two reflecting surfaces of the central prism and acquiring the return images.

[0108] Optionally, the on-orbit information acquisition module 402 is used to perform the following operations:

[0109] Determine the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the on-orbit phase. Among them, the attitude transformation matrix is ​​determined. The method involves using the angle monitoring function of the star sensor to calibrate the coordinate system of the central prism during the on-orbit phase.

[0110] Determine the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system during the on-orbit phase. Among them, the attitude transformation matrix is ​​determined. The method involves calibrating the star imagery function of the star sensor during the on-orbit phase; the star imagery function of the star sensor is achieved by acquiring star images through the star sensor.

[0111] Optionally, the load pointing determination module 403 is used to perform the following operations:

[0112] Based on the attitude transformation matrix between the reference mirror coordinate system and the star sensor measurement coordinate system during the single-machine development phase And the attitude transformation matrix between the central prism coordinate system and the reference mirror coordinate system during the AIT phase. The attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT phase is determined by the following expression:

[0113] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor monitoring coordinate system during the AIT and on-orbit phases. and The attitude transformation matrix for the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase is determined by the following expression:

[0114] Based on the attitude transformation matrix of the star sensor monitoring coordinate system from the AIT phase to the on-orbit phase Combining the correspondence between the star sensor measurement coordinate system and the star sensor monitoring coordinate system The attitude transformation matrix for the star sensor measurement coordinate system from the AIT phase to the on-orbit phase is determined by the following expression:

[0115]

[0116] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the AIT phase And the attitude transformation matrix of the star sensor measurement coordinate system from the AIT phase to the on-orbit phase. Determine the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase; the expression is:

[0117] Based on the attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase And the attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system. The attitude transformation matrix between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is determined by the following expression:

[0118] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a payload attitude determination device based on an angle-based star sensor. In other embodiments of the present invention, a payload attitude determination device based on an angle-based star sensor may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0119] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0120] In summary, this invention provides a method and apparatus for determining the attitude of a load based on an angle-monitoring star sensor, which can obtain high-precision load pointing. This invention uses a central prism as a reference to unify the reference measurement data obtained from measurements under different time and space conditions, enabling the use of angle data from a star sensor with angle monitoring function within the system. This allows the design of the star sensor's angle monitoring function to be carried out without considering the selection of the theoretical position of the image plane.

[0121] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0122] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A load attitude determination method based on an included angle monitoring star sensor, characterized in that, The system is implemented as follows; The system comprises a star sensor and a central prism; one side of the star sensor is provided with a reference mirror; the central prism is arranged on a load of a spacecraft; the central prism comprises two reflection surfaces with a fixed included angle, and is used for reflecting two paths of light beams with an included angle emitted by the star sensor respectively; The method comprises the following steps: Obtaining an angle conversion relationship between a reference mirror coordinate system and a star sensor measurement coordinate system, between a central prism coordinate system and the reference mirror coordinate system, and between the central prism coordinate system and a star sensor monitoring coordinate system in a ground phase; wherein the star sensor measurement coordinate system is a coordinate system with a set point as an origin, with an optical axis of the star sensor as a z axis, and with an imaging chip plane as an xy plane; the reference mirror coordinate system is a coordinate system with a fixed point on the reference mirror as an origin, and is designed to be the same as the star sensor measurement coordinate system in three-axis direction; the central prism coordinate system is a coordinate system with a fixed point on the central prism as an origin, and is designed to be the same as the star sensor measurement coordinate system in three-axis direction; the star sensor monitoring coordinate system is a coordinate system with a set point as an origin, with an optical axis of the star sensor as a z axis, and with a line connecting two paths of perpendicular reflection surface light beam theoretical image positions as an x axis, and with a y axis determined according to a right-hand rule; Obtaining an angle conversion relationship between the central prism coordinate system and the star sensor monitoring coordinate system, and between the star sensor measurement coordinate system and a J2000 coordinate system in an on-orbit phase; Combining a corresponding relationship between the star sensor measurement coordinate system and the star sensor monitoring coordinate system, determining an angle conversion relationship between the central prism coordinate system and the J2000 coordinate system in the on-orbit phase.

2. The method according to claim 1, characterized in that, the obtaining of the angle conversion relationship between the reference mirror coordinate system and the star sensor measurement coordinate system, between the central prism coordinate system and the reference mirror coordinate system, and between the central prism coordinate system and the star sensor monitoring coordinate system in the ground phase comprises: Determine the attitude conversion matrix between the benchmark mirror coordinate system and the star sensor measurement coordinate system in the single machine development stage Wherein, the attitude conversion matrix is used to represent the three-axis angle conversion relationship from one coordinate system to another coordinate system; the attitude conversion matrix is determined The way is to calibrate the benchmark mirror coordinate system and the star sensor measurement coordinate system at room temperature in the single machine development stage, and record the product temperature T 基准 ; Determine the attitude conversion matrix between the central prism coordinate system and the reference mirror coordinate system in the AIT stage Wherein, the attitude conversion matrix is determined in the following way: in the AIT stage, the central prism coordinate system and the reference mirror coordinate system are calibrated by the theodolite under the condition that the ambient temperature is T 基准 ​ Determine the attitude conversion matrix between the central prism coordinate system of the AIT stage and the star sensor monitoring coordinate system Wherein, the attitude conversion matrix is determined in the following manner: under the condition that the ambient temperature is T 基准 , calibrate the central prism coordinate system by using the included angle monitoring function of the star sensor; the included angle monitoring function of the star sensor is realized by emitting two light beams to the two reflecting surfaces of the central prism respectively by the star sensor and acquiring the return image.

3. The method according to claim 2, characterized in that, the obtaining of the angle conversion relationship between the central prism coordinate system and the star sensor monitoring coordinate system, and between the star sensor measurement coordinate system and the J2000 coordinate system in the on-orbit phase comprises: Determine the attitude conversion matrix between the central prism coordinate system and the star sensor monitoring coordinate system in the on-orbit stage Wherein, the attitude conversion matrix is determined by calibrating the central prism coordinate system using the included angle monitoring function of the star sensor in the on-orbit stage; Determine the attitude conversion matrix between the star sensor measurement coordinate system and the J2000 coordinate system in the on-orbit stage Wherein, the attitude conversion matrix is determined The way is to calibrate the star sky imaging function of the star sensor in the on-orbit stage; the star sky imaging function of the star sensor is realized by acquiring star sky image by the star sensor.

4. The method according to claim 1, characterized in that, the combining of the corresponding relationship between the star sensor measurement coordinate system and the star sensor monitoring coordinate system to determine the angle conversion relationship between the central prism coordinate system and the J2000 coordinate system in the on-orbit phase comprises: The attitude conversion matrix between the coordinate system of the reference mirror in the single-machine development stage and the coordinate system measured by the star sensor and the attitude conversion matrix between the coordinate system of the central prism in the AIT stage and the coordinate system of the reference mirror The attitude conversion matrix between the coordinate system of the central prism in the AIT stage and the coordinate system measured by the star sensor is determined, and the expression is: The attitude conversion matrix between the central prism coordinate system and the star sensor monitoring coordinate system in the AIT stage and on-orbit stage and The attitude conversion matrix from the AIT stage to the star sensor monitoring coordinate system in the on-orbit stage is determined, and the expression is: According to the AIT phase to the on-orbit phase star sensor monitoring coordinate system attitude conversion matrix Combined with the corresponding relationship between the star sensor measurement coordinate system and the star sensor monitoring coordinate system Determine the AIT phase to the on-orbit phase star sensor measurement coordinate system attitude conversion matrix, the expression is: The attitude conversion matrix between the central prism coordinate system of the AIT stage and the star sensor measurement coordinate system and the attitude conversion matrix from the AIT stage to the star sensor measurement coordinate system of the on-orbit stage The attitude conversion matrix between the central prism coordinate system of the on-orbit stage and the star sensor measurement coordinate system is determined, and the expression is: The attitude conversion matrix between the central prism coordinate system and the star sensor measurement coordinate system in the on-orbit stage and the attitude conversion matrix between the star sensor measurement coordinate system and the J2000 coordinate system The attitude conversion matrix between the central prism coordinate system and the J2000 coordinate system in the on-orbit stage is determined, and the expression is:

5. The method according to claim 1, characterized in that, the load is a camera.

6. The method according to claim 1, characterized in that, the star sensor is a high-precision attitude determination star sensor.

7. A device for determining a load attitude of a star sensor based on an included angle, characterized in that, the device is applied to a system comprising a star sensor and a central prism; one side of the star sensor is provided with a reference mirror; the central prism is arranged on a load of a spacecraft; the central prism comprises two reflection surfaces with a fixed included angle, and is used for reflecting two paths of light beams with an included angle emitted by the star sensor respectively; the device comprises: The in-orbit information acquisition module is configured to acquire an angle conversion relationship between the central prism coordinate system and the star sensor monitoring coordinate system in the in-orbit stage, and an angle conversion relationship between the star sensor measurement coordinate system and the J2000 coordinate system.

8. The apparatus of claim 7, wherein the in-orbit information acquisition module is configured to perform the following operation:

9. The apparatus of claim 8, wherein the in-orbit information acquisition module is configured to perform the following operation:

10. The apparatus of claim 9, wherein the load pointing determination module is configured to perform the following operation: ​ Determine the attitude conversion matrix between the benchmark mirror coordinate system and the star sensor measurement coordinate system in the single-machine development stage Wherein, the attitude conversion matrix is used to represent the three-axis angle conversion relationship from one coordinate system to another coordinate system; determine the attitude conversion matrix The way is to calibrate the benchmark mirror coordinate system and the star sensor measurement coordinate system at room temperature in the single-machine development stage, and record the product temperature T 基准 ; determining a pose conversion matrix between the central prism coordinate system and the reference mirror coordinate system in the AIT stage wherein the pose conversion matrix is determined in the AIT stage by calibrating the central prism coordinate system and the reference mirror coordinate system using a theodolite under the condition that the ambient temperature is T 基准 ​ Determine the attitude conversion matrix between the central prism coordinate system of the AIT stage and the star sensor monitoring coordinate system Wherein, the attitude conversion matrix is determined in the following manner: under the condition that the ambient temperature is T 基准 , calibrate the central prism coordinate system by using the included angle monitoring function of the star sensor; the included angle monitoring function of the star sensor is realized by emitting two light beams to the two reflecting surfaces of the central prism respectively by the star sensor and acquiring the return image. ​ ​ Determine the attitude conversion matrix between the central prism coordinate system and the star sensor monitoring coordinate system in the on-orbit stage Wherein, the attitude conversion matrix is determined The way is to calibrate the central prism coordinate system by using the included angle monitoring function of the star sensor in the on-orbit stage. Determine the attitude conversion matrix between the star sensor measurement coordinate system and the J2000 coordinate system in the on-orbit stage Wherein, the attitude conversion matrix is determined by calibrating the star sky imaging function of the star sensor in the on-orbit stage; the star sky imaging function of the star sensor is realized by acquiring star sky images by the star sensor. ​ ​ The attitude conversion matrix between the coordinate system of the reference mirror in the single-machine development stage and the coordinate system measured by the star sensor and the attitude conversion matrix between the coordinate system of the central prism in the AIT stage and the coordinate system of the reference mirror The attitude conversion matrix between the coordinate system of the central prism in the AIT stage and the coordinate system measured by the star sensor is determined, and the expression is: The attitude conversion matrix between the central prism coordinate system and the star sensor monitoring coordinate system in the AIT stage and on-orbit stage and The attitude conversion matrix from the AIT stage to the star sensor monitoring coordinate system in the on-orbit stage is determined, and the expression is: According to the AIT phase to the on-orbit phase star sensor monitoring coordinate system attitude conversion matrix Combined with the corresponding relationship between the star sensor measurement coordinate system and the star sensor monitoring coordinate system Determine the AIT phase to the on-orbit phase star sensor measurement coordinate system attitude conversion matrix, the expression is: According to the attitude conversion matrix between the central prism coordinate system of the AIT stage and the star sensor measurement coordinate system And the attitude conversion matrix from the AIT stage to the star sensor measurement coordinate system of the on-orbit stage The attitude conversion matrix between the central prism coordinate system of the on-orbit stage and the star sensor measurement coordinate system is determined, and the expression is an attitude transformation matrix between the central prism coordinate system and the star sensor measurement coordinate system during the on-orbit phase and an attitude transformation matrix between the star sensor measurement coordinate system and the J2000 coordinate system an attitude transformation matrix between the central prism coordinate system and the J2000 coordinate system during the on-orbit phase is determined, expressed as:

Images