CN-121711023-B - Laser communication terminal pointing error real-time compensation method based on orbit space-time characteristics and satellite-borne laser communication terminal

CN121711023BCN 121711023 BCN121711023 BCN 121711023BCN-121711023-B

Abstract

A real-time compensation method for the pointing error of a laser communication terminal based on the space-time characteristics of an orbit and a satellite-borne laser communication terminal, which utilizes the periodicity of satellite orbit operation to systematically correct the deviation of an installation angle caused by the thermal deformation of an installation surface and other slowly-varying factors in a multi-orbit period and angle partition iterative learning and compensation mode, specifically comprises the steps that when the terminal is operated to a certain preset angle partition in the chain building process of the first orbit period, the system synchronously records and calculates the pointing error of the interval; starting from the second track period, when the terminal runs to the learned angle partition again, the system automatically injects the partition installation angle deviation learned and stored by the last track as feedforward compensation quantity to pre-correct the current direction, and through the running of a plurality of continuous track periods, all the common working angles of the terminal can be gradually covered. The invention ensures that the pointing precision of the terminal can be dynamically maintained and continuously optimized in a long-term on-orbit task.

Inventors

CHEN XINYU
LU SHAOWEN
HOU XIA
LI JIAWEI
FAN YONGBO
CHANG ZHENYU
CHEN WEIBIAO

Assignees

中国科学院上海光学精密机械研究所

Dates

Publication Date: 20260512
Application Date: 20260214

Claims (9)

1. A real-time compensation method for the pointing error of a laser communication terminal based on the space-time characteristics of a track is characterized by comprising the following steps: s1, dividing a pointing space of a laser communication terminal into N preset discrete angle partitions according to an on-orbit working view field range of the laser communication terminal; In the track period of successfully establishing a communication link for the first time, synchronously acquiring a theoretical pointing vector and an actual pointing vector of an angle partition when the laser communication terminal operates to any angle partition; Calculating the difference between the two as an initial installation angle deviation corresponding to the angle partition, and storing the initial installation angle deviation and a corresponding angle partition mark in an associated manner to form an initial installation angle deviation mapping table; S2, starting from a second track period, when the laser communication terminal runs to a certain angle partition which has completed learning again, acquiring the current stored installation angle deviation of the angle partition as a feedforward compensation quantity; Superposing the feedforward compensation quantity and the current theoretical pointing instruction to form a corrected pointing instruction, and sending the corrected pointing instruction to a pointing executing mechanism; After the pre-correction is completed, measuring the compensated residual pointing error in real time, and updating the installation angle deviation of the corresponding angle partition based on the residual pointing error; s3, gradually completing the learning and compensation of all the common working angle partitions of the laser communication terminal through the iterative operation of a plurality of continuous track periods, and forming a mounting angle deviation mapping relation for real-time correction of the pointing error.
2. The method for compensating pointing error of a laser communication terminal in real time based on track space-time characteristics according to claim 1, wherein the pointing error comprises a slowly varying pointing error caused by thermal deformation of a mounting surface, release of structural stress, and change of thermal environment.
3. The method for compensating for pointing errors of a laser communication terminal in real time based on space-time characteristics of an orbit according to claim 1, wherein the angle division is performed according to at least one of an attitude angle, an azimuth angle and a pitch angle of the visual axis of the laser communication terminal during the orbit of a satellite.
4. The real-time compensation method for the pointing error of the laser communication terminal based on the track space-time characteristic according to claim 1, wherein the feedforward compensation quantity is overlapped with the original installation angle in the form of installation angle deviation to obtain a corrected installation angle, and the terminal pointing theoretical value is calculated based on the corrected installation angle.
5. The method for compensating pointing error of a laser communication terminal in real time based on track space-time characteristics according to claim 1, wherein the updating of the installation angle deviation adopts an iterative learning algorithm, and the iterative learning algorithm comprises at least one of weighted average, adaptive filtering or least square algorithm.
6. The method for compensating pointing errors of a laser communication terminal in real time based on track space-time characteristics according to claim 1, wherein the angle partitions gradually cover the whole common working field of view of the laser communication terminal.
7. The method for compensating pointing error of a laser communication terminal in real time based on track space-time characteristics according to claim 1, wherein the updating weight of the installation angle deviation of a certain angle partition is reduced when the residual pointing error of the certain angle partition is smaller than a preset threshold.
8. A satellite-borne laser communication terminal comprising a control processing unit, a pointing actuator and a memory, characterized in that the control processing unit is configured to perform the method for real-time compensation of pointing errors of a laser communication terminal according to any one of claims 1 to 7.
9. The satellite-borne laser communication terminal according to claim 8, wherein the control processing unit is used for generating a control signal according to a theoretical pointing instruction and/or a feedback signal, the pointing actuator is used for driving the optical component to move in response to the control signal, and the pointing measuring unit is used for measuring the actual pointing deviation between the optical axis of the terminal and the target sight line and feeding back to the control processing unit.

Description

Laser communication terminal pointing error real-time compensation method based on orbit space-time characteristics and satellite-borne laser communication terminal Technical Field The invention belongs to the technical field of space laser communication, and particularly relates to a real-time compensation method for pointing errors of a laser communication terminal based on machine learning and track space-time characteristics and a satellite-borne laser communication terminal. Background With the rapid development of low-orbit satellite constellation and space information network, satellite-borne laser communication has become an important technical means for inter-satellite communication and satellite-ground communication because of the advantages of high bandwidth, high speed, strong anti-interference capability, good confidentiality and the like. The laser communication terminal has extremely high requirements on pointing precision in the communication process, and the pointing error of the laser communication terminal directly influences the capture probability, stability and communication quality of a communication link. In the actual in-orbit running process, the laser communication terminal is usually arranged on a satellite structure platform and is influenced by factors such as periodic sunlight change, thermal environment fluctuation, structural stress release and the like, and the terminal mounting surface can generate tiny thermal deformation or attitude deviation, so that the pointing error which slowly changes along with time is introduced. The errors have the characteristics of long change period, small amplitude and obvious cumulative effect, and are difficult to eliminate for a long time by a one-time ground calibration or static compensation mode. In the prior art, the correction method for the pointing error of the laser communication terminal mainly comprises ground precise calibration, full-view-field unified installation angle compensation and correction method based on a temperature or structural model. The above method generally assumes that the angular deviation of the mounting remains consistent throughout the pointing range. However, under a complex on-orbit environment, the terminal pointing error often presents non-uniform distribution characteristics closely related to a pointing angle and a track period, and the traditional method is difficult to simultaneously consider the compensation precision and the system instantaneity. In addition, with the development trend of miniaturization and light weight of the laser communication terminal, satellite-borne calculation and storage resources are severely limited, and engineering implementation is difficult by adopting a compensation scheme of a high-complexity model or large-scale data storage. Along with the increase of the number of on-orbit operation terminals, on-orbit maintenance is increasingly complex, so that a technical scheme capable of fully utilizing the orbit operation rule and realizing long-term stable correction of the pointing error of the laser communication terminal under the condition of limited calculation and storage resources is needed. Disclosure of Invention Aiming at the problem that pointing errors caused by slow-change factors such as installation surface thermal deformation and structural stress release caused by orbit periodic thermal environment change are difficult to effectively correct for a long time in the long-term chain building operation process of the existing laser communication terminal, the invention aims to provide a real-time compensation method for the pointing errors of the laser communication terminal and a satellite-borne laser communication terminal based on machine learning and orbit space-time characteristics on the premise of not increasing hardware complexity. And taking the corresponding pointing state of the terminal under the repeatedly-appearing track position and gesture as a learning object, and realizing online learning, dynamic compensation and long-term stable correction of the pointing error of the terminal by establishing and dynamically updating an installation angle deviation mapping table of the angle division and the partition. The technical scheme of the invention is as follows: a real-time compensation method for the pointing error of a laser communication terminal based on the space-time characteristics of a track is characterized by comprising the following steps: s1, dividing a pointing space of a laser communication terminal into N preset discrete angle partitions according to an on-orbit working view field range of the laser communication terminal; In the track period of successfully establishing a communication link for the first time, synchronously acquiring a theoretical pointing vector and an actual pointing vector of an angle partition when the laser communication terminal operates to any angle partition; Calculating the difference between the two as