A satellite laser communication terminal relative pose measurement system based on an eddy current sensor

Abstract

The application is a satellite laser communication terminal relative position measurement system based on an eddy current sensor, which comprises a communication terminal connecting plate, an axial sensor system, a radial sensor system, a position calculation circuit system, a passive and active hybrid damper and a single pendulum mirror type laser communication terminal. The axial sensor system is composed of an axial sensor support, an eddy current sensor and an axial sensor target surface; the radial sensor system is composed of a radial sensor support, an eddy current sensor and a radial sensor target surface. The application can measure the relative position of the satellite laser communication terminal relative to the satellite body with high precision, and has the characteristics of high precision, low power consumption and low complexity. Therefore, the application can meet the needs of the relative position measurement of the satellite laser communication terminal with a vibration isolation and damping link, and solve the problem that the boresight direction of the laser communication terminal is difficult to calculate after the laser communication terminal relative to the satellite body has a relative displacement after the vibration isolation and damping link is added.

Description

Technical Field

[0001] This invention belongs to the field of space optical communication and precision pose measurement technology, specifically relating to a satellite laser communication terminal relative pose measurement system based on an eddy current sensor. Background Technology

[0002] With the rapid development of space communication technology, laser communication, due to its advantages of high bandwidth, low power consumption, and strong anti-interference capability, is gradually becoming a key means of high-speed data transmission between future satellites. However, the laser beam used for communication has an extremely small divergence angle, requiring precise measurement of the relative position between the two communication terminals to establish a laser link.

[0003] Micro-vibrations of the satellite platform itself can affect the beam pointing stability of the communication terminal. Vibration isolation devices can effectively suppress these disturbances, but this leads to changes in the relative pose between the communication terminal and the satellite platform. This prevents the calculation of the relative position between the two communication terminals using the satellite platform's attitude and orbit information, thus affecting the establishment of the communication link. Therefore, real-time and accurate measurement of the pose change of the communication terminal relative to the satellite platform is crucial for improving the robustness of the laser communication system. Currently, common pose measurement methods include optical interferometry and inertial measurement units (IMUs), but these methods are susceptible to drift, error accumulation, or ambient light interference in complex space environments and are also highly complex. Eddy current sensors, due to their non-contact, high-precision, and high-bandwidth characteristics, have become an ideal pose measurement solution. They can achieve high-precision real-time measurement of the relative pose of the communication terminal under different environmental conditions, enabling rapid laser communication link establishment. Summary of the Invention

[0004] To address the increased uncertainty in terminal pointing and difficulties in calculating the target terminal position caused by adding vibration damping and isolation devices to existing laser communication terminals, this invention proposes a relative attitude measurement system for satellite laser communication terminals based on eddy current sensors. This invention uses eddy current sensors as the measuring mechanism to measure the relative displacement between the satellite platform and the laser communication terminal, realizing the calculation process from satellite attitude to terminal pointing, reducing the uncertainty in terminal pointing and target terminal position calculations, and ensuring the pointing accuracy of the communication terminal.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A satellite laser communication terminal relative pose measurement system based on eddy current sensors includes a single-pendulum mirror laser communication terminal, a communication terminal connection plate, a hybrid active-passive vibration damper, an axial sensor system, a radial sensor system, and a pose calculation circuit system. The single-pendulum mirror laser communication terminal is bolted to the communication terminal connection plate, which is connected to the satellite platform via the hybrid active-passive vibration damper to reduce the impact of vibration on the communication terminal. The axial and radial sensor systems are installed between the communication terminal connection plate and the satellite platform, respectively, to measure the relative angular displacement along the z-axis and xy-plane directions. The pose calculation circuit system acquires the sensor data and calculates the pose change of the communication terminal relative to the satellite platform, including angular displacement around the x, y, and z axes.

[0007] The advantages of this invention over existing pose measurement technologies are:

[0008] 1. High measurement accuracy. This invention uses an eddy current sensor as the measurement sensor, which can achieve a measurement accuracy of less than 1 microradian.

[0009] 2. Non-contact measurement. This invention uses an eddy current sensor as the measurement sensor. During measurement, there is no need for contact with the object being measured, no additional force is introduced, and the impact on the mechanism is minimal.

[0010] 3. Simple structure and low power consumption. Compared with using gyroscopes or star sensors for pose measurement, the measurement method adopted in this invention has a simpler structure and lower power consumption.

[0011] 4. No mechanical noise is generated. The measurement method used in this invention has no moving parts and will not generate additional vibration. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to the present invention;

[0013] Figure 2 This is a schematic diagram of the axial measurement system structure in this invention;

[0014] Figure 3 This is a schematic diagram of the radial measurement system structure in this invention;

[0015] Figure 4 This is a block diagram of the relative pose calculation of the measurement system of the present invention.

[0016] The labels in the diagram are explained as follows:

[0017] 1-Single pendulum mirror laser communication terminal, 2-Communication terminal connection plate, 3-Active and passive hybrid vibration damper, 4-Axial sensor system, 5-Radial sensor system;

[0018] 401-Axial sensor bracket, 402-Axial eddy current sensor, 403-Axial sensor target surface;

[0019] 501 - Radial sensor bracket, 502 - Radial eddy current sensor, 503 - Radial sensor target surface. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above objectives, this invention adopts the following technical solution.

[0021] like Figure 1 As shown, a satellite laser communication terminal relative pose measurement system based on eddy current sensors includes a single-pendulum mirror laser communication terminal 1, a communication terminal connecting plate 2, an active-passive hybrid vibration damper 3, an axial sensor system 4, a radial sensor system 5, and a pose calculation circuit system. The single-pendulum mirror laser communication terminal 1 is bolted to the communication terminal connecting plate 2, which is connected to the satellite platform via the active-passive hybrid vibration damper 3 to reduce the impact of vibration on the communication terminal. The axial sensor system 4 and the radial sensor system 5 are installed between the communication terminal connecting plate 2 and the satellite platform, respectively, to measure the relative angular displacement along the z-axis and xy-plane directions. The pose calculation circuit system acquires sensor data and calculates the pose change of the single-pendulum mirror laser communication terminal 1 relative to the satellite platform, including angular displacement around the x-axis, y-axis, and z-axis.

[0022] The communication terminal connection plate 2 is bolted to the side mounting flange of the single-pendulum mirror laser communication terminal 1. The upper end of the active-passive hybrid vibration damper 3 is bolted to the communication terminal connection plate 2, and the lower end of the active-passive hybrid vibration damper 3 is bolted to the satellite platform, thus being fixed to the satellite. The axial sensor bracket 401 of the axial sensor system 4 is bolted to the lower surface of the communication terminal connection plate 2. The axial sensor bracket 401 is threaded to the axial eddy current sensor 402, and the axial sensor target surface 403 is bolted to the outer surface of the satellite platform, thus being fixed to the satellite. The radial sensor bracket 501 of the radial sensor system 5 is bolted to the outer cylindrical surface of the communication terminal connection plate 2. The radial sensor bracket 501 is threaded to the radial eddy current sensor 502, and the radial sensor target surface 503 is bolted to the outer surface of the satellite platform, thus being fixed to the satellite.

[0023] Preferred, such as Figure 1As shown, three or more axial sensor systems 4 are arranged around the circumference of the communication terminal connecting plate 2, and their measurement directions are not collinear or parallel to the xy plane. The relative rotation of the single-pendulum laser communication terminal 1 relative to the satellite body around the x and y axes can be calculated using the measurement data of the axial sensor systems 4. The measurement directions of two or more radial sensor systems 5 are not parallel to the z-axis. The rotation of the single-pendulum laser communication terminal 1 relative to the satellite body around the z-axis can be calculated using the measurement data of the radial sensor systems 5.

[0024] Preferred, such as Figure 2 As shown, the axial sensor system 4 consists of an axial sensor bracket 401, an axial eddy current sensor 402, and an axial sensor target surface 403. The axial sensor bracket 401 is bolted to the lower surface of the communication terminal connection plate 2. The axial sensor bracket 401 engages with the axial eddy current sensor 402 via a threaded pair. The axial sensor target surface 403 is bolted to the outer surface of the satellite platform and fixed to the satellite. To meet the measurement requirements of the eddy current sensor, a gap exists between the axial eddy current sensor 402 and the axial sensor target surface 403. The pose calculation circuit system can measure the relative distance between the axial eddy current sensor 402 and the axial sensor target surface 403. To facilitate adjustment of the gap between the axial eddy current sensor 402 and the axial sensor target surface 403 after system assembly, the axial sensor bracket 401 and the axial eddy current sensor 402 are engaged via a threaded pair. The gap can be adjusted by screwing the axial eddy current sensor 402 in or out, ensuring that the working gap is within the linear region of the axial eddy current sensor 402. The axial eddy current sensor 402 and the axial sensor bracket 401 are fixed by adjusting the gap using a threaded joint. A gap exists between the axial eddy current sensor 402 and the axial sensor target surface 403, consisting of a material such as air that allows relative displacement between them. The number of axial sensor systems 4 is not limited to three, and the measurement direction is not limited to the z-direction; it also includes arrangements capable of forming three sets of measurement vectors not perpendicular to the z-direction. Preferably, as shown... Figure 3As shown, the radial sensor system 5 consists of a radial sensor bracket 501, a radial eddy current sensor 502, and a radial sensor target surface 503. The radial sensor bracket 501 is bolted to the lower surface of the communication terminal connection plate 2. The radial sensor bracket 501 engages with the radial eddy current sensor 502 via a threaded pair. The radial sensor target surface 503 is bolted to the outer surface of the satellite platform and fixed to the satellite. To meet the measurement requirements of the eddy current sensor, a gap exists between the radial eddy current sensor 502 and the radial sensor target surface 503. The pose calculation circuit system can measure the relative distance between the radial eddy current sensor 502 and the radial sensor target surface 503. To facilitate adjustment of the gap between the radial eddy current sensor 502 and the radial sensor target surface 503 after system assembly, the radial sensor bracket 501 and the radial eddy current sensor 502 are engaged via a threaded pair. The gap can be adjusted by screwing the radial eddy current sensor 502 in or out, ensuring that the working gap is within the linear region of the radial eddy current sensor 502. The radial eddy current sensor 502 and the axial sensor bracket 501 are fixed by adjusting the gap through a threaded connection. A gap exists between the radial eddy current sensor 502 and the radial sensor target surface 503, consisting of a material such as air that allows relative displacement between them. The number of axial sensor systems 5 is not limited to two, and the measurement direction is not limited to parallel to the xy plane; it also includes arrangements capable of forming two sets of measurement vectors not along the z-direction.

[0025] The pose calculation circuit system mainly consists of a power supply circuit, an eddy current preamplifier, and a microcontroller. Preferably, the pose calculation circuit system is installed inside the satellite or the communication terminal, and it employs digital devices such as a microcontroller and a programmable logic processor. The pose calculation circuit system can acquire measurement signals from the axial and radial sensor systems and calculate the relative displacement of the communication terminal relative to the satellite platform, including rotation in three directions.

[0026] like Figure 4 As shown, the relative rotation of the single-pendulum laser communication terminal 1 relative to the satellite platform about the x-axis and y-axis is obtained by the algorithm through the measurement values ​​of at least three axial sensors; the relative rotation of the single-pendulum laser communication terminal 1 relative to the satellite platform about the z-axis is obtained by the algorithm through the measurement values ​​of at least two radial sensors.

[0027] The above descriptions are merely embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles set forth in the present invention, or directly or indirectly applied to other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A relative pose measurement system for a satellite laser communication terminal based on an eddy current sensor, characterized in that, include: The system comprises a single-pendulum mirror laser communication terminal (1), a communication terminal connecting plate (2), an active-passive hybrid vibration damper (3), an axial sensor system (4), a radial sensor system (5), and a pose calculation circuit system. The single-pendulum mirror laser communication terminal (1) is fixed on the communication terminal connecting plate (2), which is connected to the satellite platform via the active-passive hybrid vibration damper (3). The axial sensor system (4) and the radial sensor system (5) are installed between the communication terminal connecting plate (2) and the satellite platform, respectively, to measure the relative angular displacement along the z-axis and the xy-plane. The pose calculation circuit system is used to calculate the pose change of the single-pendulum mirror laser communication terminal (1) relative to the satellite platform, including the angular displacement around the x-axis, y-axis, and z-axis.

2. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 1, characterized in that, The single-pendulum mirror laser communication terminal (1) is fixedly connected to the upper surface of the communication terminal connecting plate (2); the upper end of the active-passive hybrid vibration damper (3) is fixedly connected to the side of the communication terminal connecting plate (2), and the lower end of the active-passive hybrid vibration damper (3) is fixedly connected to the satellite platform; the upper end of the axial sensor system (4) is fixedly connected to the lower surface of the communication terminal connecting plate (2), and the other end of the axial sensor system (4) is fixedly connected to the satellite platform; the upper end of the radial sensor system (5) is fixedly connected to the lower surface of the communication terminal connecting plate (2), and the other end of the radial sensor system is fixedly connected to the satellite platform; the pose calculation circuit system is connected to the axial sensor system (4) and the radial sensor system (5) through cables.

3. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 1, characterized in that, The number of axial sensor systems (4) is not less than 3; the measurement direction of the axial sensor system (4) includes vectors that are parallel to the z-axis and are not collinear with each other.

4. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 1, characterized in that, The number of radial sensor systems (5) is not less than two, and the measurement directions of the radial sensor systems (5) include vectors that are not collinear on the xy plane.

5. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 3, characterized in that, The system uses no fewer than three axial sensor systems (4) to calculate the relative displacement of the single pendulum laser communication terminal (1) relative to the satellite platform, including rotation around the x-axis and rotation around the y-axis, and the system uses no fewer than three radial sensor systems (5) to calculate the relative displacement of the single pendulum laser communication terminal (1) relative to the satellite platform, including rotation around the z-axis.

6. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 4, characterized in that, At least two radial sensor systems (5) are used to calculate the relative displacement of the single-pendulum laser communication terminal (1) relative to the satellite platform, including rotation around the z-axis.

7. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 1, characterized in that, The axial sensor system (4) includes an axial sensor bracket (401), an axial eddy current sensor (402), and an axial sensor target (403). The axial sensor bracket (401) and the axial eddy current sensor (402) are connected by a threaded pair, and there is a measurement gap between the axial eddy current sensor (402) and the axial sensor target (403).

8. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 1, characterized in that, The radial sensor system (5) includes a radial sensor bracket (501), a radial eddy current sensor (502), and a radial sensor target (503). The radial sensor bracket (501) and the radial eddy current sensor (502) are connected by a threaded pair, and there is a measurement gap between the radial eddy current sensor (502) and the radial sensor target (503).

9. The satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 1, characterized in that, The upper end of the axial sensor system (4) is fixed to the lower surface of the communication terminal connecting plate (2) by bolts, and the other end of the axial sensor system (4) is fixed to the satellite platform by three connecting holes.

10. A satellite laser communication terminal relative pose measurement system based on an eddy current sensor according to claim 1, characterized in that, The upper end of the radial sensor system (5) is fixed to the lower surface of the communication terminal connecting plate (2) by bolts, and the other end of the radial sensor system (5) is fixed to the satellite platform through three connecting holes.

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