System-level verification method for calibrating direction of multi-beam antenna by star sensor

Abstract

The invention provides a system-level verification method for star-sensitive calibration of multi-beam antenna pointing, and the method comprises the steps: generating an orbit position speed parameter through an orbit parameter simulator, and transmitting the orbit position speed parameter to an antenna controller through a satellite service computer; in antenna controller ground test equipment, the angle of a bias mechanism is adjusted to be an initial value of 0 degree, a corresponding quaternion is calculated and sent to a dynamic star model, and the dynamic star model generates a star map signal according to the quaternion and sends the star map signal to a calibration star sensor; the antenna controller verifies that the current mechanism angle is 0 degree according to the quaternion uploaded by the calibration star sensor in combination with the orbit position speed parameter and then marks the initial state; adjusting a target offset angle value, calculating a corresponding quaternion, sending the quaternion to a dynamic star module, calibrating a star sensor, uploading the quaternion based on feedback, and verifying that a mechanism angle is consistent with the target offset angle by an antenna controller according to the quaternion; the analog load motor or the antenna reflecting surface is driven to rotate, the antenna controller ground test equipment detects the angle change in real time, calculates the current angle value and the corresponding quaternion and feeds back the current angle value and the corresponding quaternion to the antenna controller, and the antenna controller drives the motor to adjust the angle based on a calibration algorithm until the difference value between the offset angle and 0 degree reaches a preset threshold value. Therefore, the aim of verifying the function, the performance and the polarity of the system can be fulfilled only by directly testing the calibration pointing function of the star sensor, and the operation is simple and economical.

Description

Technical Field

[0001] The present invention relates to the field of satellite technology, and particularly to a system-level verification method for star sensor calibration of multi-beam antenna pointing. Background Art

[0002] In recent years, more and more operators of communication satellites have deployed high-throughput payload satellites (hereinafter referred to as HTS satellites). The number and proportion of HTS satellites are increasing significantly. HTS satellites mostly adopt the form of multi-point beam antennas, and the frequency can be multiplexed multiple times to improve the satellite capacity. Currently, the beam width of the multi-beam used in high-throughput satellites is 0.5° - 2°. With the development of multi-beam feeder technology, the beam width can reach 0.1° or even less in the future. Generally, the satellite beam pointing is affected by mechanical installation errors, platform attitude errors, and thermal deformation errors of the antenna itself. To ensure the pointing accuracy of the multi-beam antenna, a beam calibration pointing system is usually configured on high-throughput satellites. Traditionally, satellites adopt the strategy of configuring a capture and tracking calibration system to achieve the pointing calibration of the spot beam antenna and ensure that the pointing accuracy of the satellite antenna meets the requirements.

[0003] When using a capture and tracking calibration system, satellites usually need to configure equipment such as calibration feeders, low-noise amplifiers, capture and tracking receivers, waveguides, and RF cables. Configuring so many devices will occupy the weight of the satellite payload. Generally, the weight of the calibration system reaches 12 - 15 kg. At the same time, a calibration ground station needs to be configured on the ground to form a space-ground capture and tracking link to cooperate to complete the capture and tracking beam pointing calibration task.

[0004] For traditional antenna pointing calibration methods, which adopt the capture and tracking calibration mode, on-orbit cooperation between space and ground is required to achieve it. When conducting ground tests on the system, multiple devices such as ground signal sources, phase shifters, RF cables, and spectrum analyzers are needed. At the same time, the correctness of the system design needs to be indirectly verified through test items such as test dynamic range, error signal characteristics, angular error zero drift, Doppler compensation performance of the capture and tracking receiver, and automatic tracking test. At the same time, to ensure the correct polarity between space and ground, a far-field joint test of the capture and tracking calibration system is required; its operation is cumbersome and costly.

[0005] By installing a star sensor at a suitable position on the multi-beam antenna to be calibrated and cooperating with software to achieve on-board self-closed-loop calibration of the multi-beam antenna pointing, it is much more economical and efficient compared to the traditional capture and tracking system. As a new type of antenna pointing calibration system, the correctness and matching of the system design of star sensor calibration of the multi-beam antenna pointing need to be tested and verified at the system level on the ground. Therefore, there is an urgent need for a method that can conduct system-level tests on star sensor calibration beam pointing to verify the correctness and matching of the design of the star sensor calibration multi-beam pointing system configured on the satellite. Summary of the Invention

[0006] The purpose of the present invention is to provide a system-level verification method for star sensor calibration of multi-beam antenna pointing, which is used for system-level testing of the star sensor calibration beam pointing system to verify the correctness and matching of the system.

[0007] To achieve the above object, the present invention provides a system-level verification method for star sensor calibration of multi-beam antenna pointing, including the following steps:

[0008] Connect the on-board equipment to be tested with the ground test system; wherein, the ground test system includes a dynamic star model, an antenna controller ground test device, a satellite telemetry and telecontrol ground processing device, and an orbit parameter simulator, and the on-board equipment includes a spacecraft computer, an antenna controller, and a calibration star sensor;

[0009] Generate orbit position and velocity parameters through the orbit parameter simulator, and forward them to the antenna controller through the spacecraft computer; adjust the angle of the bias mechanism to the initial value of 0° in the antenna controller ground test device to calculate the corresponding first set of quaternions and send them to the dynamic star model; the dynamic star model generates a star map signal based on the first set of quaternions and transmits it to the calibration star sensor; the calibration star sensor generates the first set of quaternions based on the star map signal and uploads them to the antenna controller; after the antenna controller combines the first set of quaternions and the orbit position and velocity parameters to verify that the current mechanism angle is 0°, mark the initial state;

[0010] Adjust the target bias angle value in the antenna controller ground test device to calculate the corresponding second set of quaternions and send them to the dynamic star model; the calibration star sensor generates the second set of quaternions based on the feedback information of the dynamic star model and uploads them to the antenna controller; the antenna controller verifies that the mechanism angle is consistent with the target bias angle according to the received third set of quaternions and the orbit position and velocity parameters;

[0011] Drive the simulated load motor or the antenna reflector to rotate, and detect the angle change in real time through the antenna controller ground test device to calculate the current angle value and the corresponding quaternions, and feedback them to the antenna controller; the antenna controller drives the motor to adjust the angle based on the calibration algorithm, and when the difference between the bias angle and 0° reaches the preset threshold value, the closed-loop verification is completed.

[0012] Optionally, the satellite telemetry and telecontrol ground processing device, the orbit parameter simulator are connected to the spacecraft computer through a 1553B bus, the antenna controller ground test device is connected to the dynamic star model through a network cable, and the calibration star sensor is connected to the antenna controller through an RS422 bus.

[0013] Optionally, the calibration star sensor is installed at the joint of the satellite antenna arm and the antenna reflector to sense the antenna pointing state.

[0014] Optionally, the preset threshold value is 0.02°.

[0015] Optionally, the dynamic star model is used to simulate the star map data collected by the star sensor during on-orbit operation, and generate corresponding dynamic star map signals according to the input quaternion.

[0016] Optionally, the orbital position and velocity parameters include satellite position, velocity, and attitude information for simulating the on-orbit operating environment.

[0017] The system-level verification method for calibrating the multi-beam antenna pointing by the star sensor according to the present invention simulates the on-orbit environment through a ground test system, directly senses the antenna pointing state by using a lightweight calibrated star sensor, generates star map signals in combination with a dynamic star model, and constructs a closed-loop calibration verification system. This method abandons the ground station and complex radio frequency equipment required by the traditional acquisition and tracking calibration system, and uses the high-precision attitude measurement characteristics of the star sensor to complete the system-level verification of the multi-beam antenna pointing without the need for a large ground-space closed loop, significantly reducing the satellite payload weight, simplifying the test process, and providing an efficient and economical solution for the precise pointing of multi-beams of high-throughput satellites. Brief Description of the Drawings

[0018] Figure 1 It is a flowchart of the steps of the system-level verification method for calibrating the multi-beam antenna pointing by the star sensor provided by an embodiment of the present invention;

[0019] Figure 2 It is a schematic connection diagram between the ground test system adopted by the system-level verification method for calibrating the multi-beam antenna pointing by the star sensor provided by an embodiment of the present invention and the on-board equipment to be tested;

[0020] Figure 3 It is a schematic installation diagram of the calibrated star sensor of the system-level verification method for calibrating the multi-beam antenna pointing by the star sensor provided by an embodiment of the present invention. Detailed Description of the Embodiment

[0021] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] It should be noted that the references to "one embodiment", "embodiment", "exemplary embodiment", etc. in this specification mean that the described embodiment may include specific features, structures, or characteristics, but not every embodiment must include these specific features, structures, or characteristics. In addition, such expressions do not refer to the same embodiment. Further, when combining specific features, structures, or characteristics with an embodiment, whether or not there is an explicit description, it has been shown that combining such features, structures, or characteristics with other embodiments is within the knowledge of those skilled in the art.

[0023] In addition, in the specification and subsequent claims, certain terms are used to refer to specific components or parts. Those of ordinary skill in the art should understand that manufacturers may use different nouns or terms to refer to the same component or part. This specification and subsequent claims do not use the difference in name as a way to distinguish components or parts, but use the difference in function of components or parts as the criterion for distinction. The terms "comprising" and "including" mentioned throughout the specification and subsequent claims are open-ended terms, so they should be interpreted as "including but not limited to". In addition, the term "connected" herein includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0024] Before describing the embodiments of the present application in detail, first briefly describe the technical concept of the present application: Satellite star sensors are usually used to measure the attitude of satellites and are used as sensors in satellite control systems. For example, if the star sensor is installed on the satellite antenna arm or the back of the antenna transmitting surface, the measurement of the beam pointing of the antenna itself can be realized. By comparing with the target pointing of the antenna beam, the difference from the target pointing can be obtained, and the difference is transmitted back to the antenna controller. The antenna controller drives the X and Y axes of the antenna to rotate towards the target pointing according to the target pointing requirement. When the difference from the target pointing is less than a certain threshold (usually 0.02° or less), the antenna pointing calibration is finally realized. As a new calibration method for the star sensor to calibrate the satellite beam pointing, how to test and verify the star sensor calibration antenna pointing system on the ground and verify the correctness and coordination of the star sensor calibration algorithm and the star sensor calibration system is of decisive significance for the normal calibration work of the system in orbit. The method provided by the present invention is as follows: (1) Build a ground test system including a dynamic star model and an orbit parameter simulator to simulate satellite attitude and orbit data; (2) Dynamically associate the antenna offset angle with the star map data through a quaternion conversion mechanism to calibrate the real-time feedback of the star sensor on the antenna pointing deviation; (3) The antenna controller drives the reflector adjustment based on the calibration algorithm to gradually converge the offset angle to a preset threshold (such as 0.02°) to achieve closed-loop verification.

[0025] The following describes the specific principle of the system-level verification method for calibrating the multi-beam antenna pointing of the star sensor of the present application in combination with specific embodiments.

[0026] Figure 1 A system - level verification method for the pointing of a star - sensor - calibrated multi - beam antenna provided by an embodiment of the present invention is shown, and the steps are as follows:

[0027] S101: Connect the on - satellite equipment to be tested to the ground test system; wherein, the ground test system includes a dynamic satellite model, a ground test device for the antenna controller, a ground processing device for satellite telemetry and telecontrol, and an orbit parameter simulator, and the on - satellite equipment includes a satellite bus computer, an antenna controller, and a calibration star - sensor; the connection relationship in this embodiment is as Figure 2 shown. Preferably, the ground processing device for satellite telemetry and telecontrol and the orbit parameter simulator are connected to the satellite bus computer through a 1553B bus, the ground test device for the antenna controller is connected to the dynamic satellite model through a network cable, and the calibration star - sensor is connected to the antenna controller through an RS422 bus.

[0028] The star - sensor used in the satellite star - sensor calibration system is generally a micro - nano star - sensor, usually weighing about dozens of grams. Compared with the traditional acquisition and tracking calibration system, the weight can be basically ignored, and the saved weight can be used to configure more payloads, further improving the carrier - to - interference ratio of the satellite. Among them, the calibration star - sensor is installed at the joint of the satellite antenna arm and the antenna reflector to sense the antenna pointing state. After completing the connection between the device under test and the ground test system, power on all the ground test system devices.

[0029] S102: Generate orbit position and velocity parameters through the orbit parameter simulator, and forward them to the antenna controller through the satellite bus computer; adjust the bias mechanism angle to the initial value of 0° in the ground test device for the antenna controller to calculate the corresponding first set of quaternions and send them to the dynamic satellite model; the dynamic satellite model generates a star map signal based on the first set of quaternions and transmits it to the calibration star - sensor; the calibration star - sensor generates the first set of quaternions according to the star map signal and uploads them to the antenna controller; after the antenna controller combines the first set of quaternions and the orbit position and velocity parameters to verify that the current mechanism angle is 0°, mark the initial state.

[0030] The dynamic satellite model is used to simulate the star map data collected by the star - sensor during on - orbit operation and generate the corresponding dynamic star map signal according to the input quaternions.

[0031] During specific implementation, the orbital parameter simulator simulates the data collected by the star sensor of the control system during on-orbit operation to generate orbital position and velocity parameters, where the orbital position and velocity parameters include satellite position, velocity, and attitude information for simulating the on-orbit operating environment. Then, it is forwarded to the antenna controller by the on-board computer. In the antenna controller ground test equipment, the offset mechanism angle is set to 0. The antenna controller ground test equipment calculates the quaternion corresponding to the 0 angle and sends it to the dynamic star model. The dynamic star model generates a star map and transmits it to the calibration star sensor. After the calibration star sensor senses the star map, it generates a quaternion and transmits it to the antenna controller, so that the antenna controller can calculate that the mechanism angle in this state should also be 0 by combining the orbital position and velocity parameters. That is, after verifying their consistency, the reference setting instruction can be triggered to mark this state as the initial state.

[0032] S103: Adjust the target offset angle value in the antenna controller ground test equipment to calculate the corresponding second set of quaternions and send them to the dynamic star model; the calibration star sensor generates the second set of quaternions based on the feedback information of the dynamic star model and uploads them to the antenna controller; the antenna controller verifies that the mechanism angle is consistent with the target offset angle according to the received third set of quaternions and the orbital position and velocity parameters. That is, by inputting an X-axis angle offset of a for a certain antenna in the antenna controller ground test equipment, the quaternion corresponding to the offset angle a is calculated by software at this time and sent to the dynamic star model; the dynamic star model generates a star map and feeds it back to the calibration star sensor. The calibration star sensor generates the corresponding quaternion and sends it to the antenna controller. After receiving this quaternion, the antenna controller calculates that the mechanism angle should also be a by combining the orbital position and velocity parameters. For example, by inputting an X-axis or Y-axis angle offset of 2° for the east antenna north in the antenna controller ground test equipment, the quaternion corresponding to the offset angle of 2° is calculated by software at this time and sent to the dynamic star model. After receiving this quaternion, the antenna controller calculates that the mechanism angle should also be 2° by combining the orbital position and velocity parameters. If the verification is consistent, proceed to the next step; otherwise, check the status of each device and related parameters.

[0033] S104: Drive the simulated load motor or the antenna reflector to rotate, and detect the angle change in real time through the ground test equipment of the antenna controller to calculate the current angle value and the corresponding quaternion, and feedback it to the antenna controller; based on the calibration algorithm, the antenna controller drives the motor to adjust the angle, and when the difference between the offset angle and 0° reaches the preset threshold, the closed-loop verification is completed. Specifically, a star sensor calibration start command can be generated to trigger the antenna controller to start driving the simulated load motor or the antenna reflector (such as the reflector of the east antenna or the north antenna) to rotate. The ground processing equipment of the antenna controller detects the angle change, calculates the current angle value, and infers the corresponding quaternion information at this angle according to this angle value, and transmits it to the antenna controller. The antenna controller drives the antenna motor to rotate according to the calibration algorithm, driving the antenna arm and the reflector to rotate. As the motor rotates, the initial angle deviation a gradually decreases until it finally approaches 0; when the difference between the current angle and 0 reaches the preset threshold of the calibration, the closed-loop calibration is completed, and this calibration is ended by sending a star sensor calibration stop command.

[0034] The preset threshold value of this embodiment is 0.02°; that is, when the difference between the current angle and 0 reaches the preset threshold value of 0.02° of the calibration, the closed-loop calibration is completed, the antenna motor stops rotating, and this calibration is ended by the star sensor calibration stop command.

[0035] Optionally, the calibration algorithm of this embodiment drives the motor to adjust the angle of the antenna reflector by iteratively calculating the quaternion deviation until the deviation is less than the preset threshold value.

[0036] For high-throughput communication satellites, which include more than one antenna reflector, the pointing error calibration test of other antenna reflectors can also be implemented by using the method provided by the present invention.

[0037] In summary, the system-level verification method for star sensor calibration of the multi-beam antenna pointing described in the present invention uses star sensor calibration of the antenna pointing to overcome the deficiencies of the original acquisition and tracking calibration mode. It does not require the participation of the ground station, and only the satellite can achieve closed-loop calibration. Therefore, there is no need to build a ground calibration station to achieve the large closed-loop calibration between the satellite and the ground; compared with the traditional acquisition and tracking calibration system test, the present invention only needs to directly test the star sensor calibration pointing function to achieve the purpose of verifying the system function, performance and polarity; it can significantly reduce the weight of the satellite payload, simplify the test process, and provide an efficient and economical solution for the multi-beam accurate pointing of high-throughput satellites.

[0038] Of course, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A system-level verification method for star-sensing calibration of multi-beam antenna pointing, characterized in that: The following steps are involved: Connecting the onboard equipment to be tested to the ground test system; wherein the ground test system includes a dynamic star model, an antenna controller ground test equipment, a satellite telemetry and remote control ground processing equipment and an orbit parameter simulator, and the onboard equipment includes a satellite computer, an antenna controller and a calibration star sensor; Generate orbital position velocity parameters through the orbital parameter simulator, and forward them to the antenna controller through the satellite computer; adjust the paranoid mechanism angle to the initial value 0° in the ground test equipment of the antenna controller to calculate the corresponding first set of quaternions and send them to the dynamic star model; the dynamic star model generates a star map signal based on the first set of quaternions and transmits it to the calibration star sensor; the calibration star sensor generates the first set of quaternions according to the star map signal and uploads it to the antenna controller; the antenna controller verifies that the current mechanism angle is 0° in combination with the first set of quaternions and the orbital position velocity parameters, and then marks the initial state; The target offset angle value is adjusted in the ground test equipment of the antenna controller to calculate the corresponding second set of quaternions and send them to the dynamic star model; the calibration star sensor generates the second set of quaternions based on the feedback information of the dynamic star model and uploads them to the antenna controller; the antenna controller verifies that the mechanism angle is consistent with the target offset angle according to the received third set of quaternions and the orbital position speed parameters; Drive the simulated load motor or antenna reflector to rotate, and detect the angle change in real time through the antenna controller ground test equipment to calculate the current angle value and the corresponding quaternion, and feed back to the antenna controller; the antenna controller drives the motor to adjust the angle based on the calibration algorithm to complete the closed-loop verification when the difference between the offset angle and 0° reaches the preset threshold value.

2. The method according to claim 1, characterized in that: The satellite telemetry and remote control ground processing equipment, the orbit parameter simulator and the star service computer are connected via a 1553B bus, the antenna controller ground test equipment and the dynamic star model are connected via a network cable, and the calibration star sensor and the antenna controller are connected via an RS422 bus.

3. The method according to claim 1, characterized in that: The calibration star sensor is installed at the junction of the satellite antenna arm and the antenna reflector to sense the antenna pointing state.

4. The method according to claim 1, characterized in that The preset threshold value is 0.02°.

5. The method according to claim 1, characterized in that The dynamic star model is used to simulate the star map data collected by the star sensor while on orbit, and to generate a corresponding dynamic star map signal according to the input quaternion.

6. The method according to any one of claims 1 to 5, characterized in that: The orbital position and velocity parameters include satellite position, velocity and attitude information used to simulate the on-orbit operating environment.

Images