CN-116007657-B - Astronomical calibration method for synchronizing small-view-field camera and star-sensitive measurement reference

CN116007657BCN 116007657 BCN116007657 BCN 116007657BCN-116007657-B

Abstract

The invention discloses an astronomical calibration method for synchronizing a small-view-field camera and a star-sensitive measurement reference, which comprises the following steps of S1, adopting a space-based small-view-field camera and a star-sensitive camera to simultaneously expose and scan a space area corresponding to respective view fields, obtaining a desired star image shot by the small-view-field camera and a satellite inertial quaternion under a star-sensitive measurement coordinate system, S2, calculating vector coordinates of a star in the star-sensitive measurement coordinate system and the star-based small-view-field camera measurement coordinate system by the star-sensitive camera according to measurement information of the space-based small-view-field camera and the star-sensitive camera, S3, calculating estimated values of measurement offset angles of the space-based small-view-field camera and the star-sensitive camera through an optimal estimation algorithm, and S4, setting limiting conditions of the estimation algorithm in the step S3, including limiting the estimated values and timing the estimation algorithm. The invention has high identification precision, the identification data can be directly used for the next load task, the gesture determination and task precision are improved, and the invention has stronger engineering practicability.

Inventors

SHAO ZHIJIE
LIU XIAO
MENG QICHEN
GUO ZHENGYONG
DAI WEIZONG
FENG BAOMIN
HUANG YEPING
SHEN QINGFENG

Assignees

上海航天控制技术研究所

Dates

Publication Date: 20260512
Application Date: 20221229

Claims (5)

1. A method for calibrating astronomical system by synchronizing a small-view-field camera with a star-sensitive measurement reference is characterized by comprising the following steps of S1, adopting a small-view-field camera with a star-sensitive camera to simultaneously expose and scan a space where an expected star is located, obtaining an expected star image shot by the small-view-field camera and a satellite inertial quaternion under a star-sensitive measurement coordinate system, S2, calculating vector coordinates of the star in the star-sensitive measurement coordinate system and the star-sensitive measurement coordinate system respectively according to measurement information of the small-view-field camera with the star-sensitive camera, S3, calculating estimated values of measurement offset angles of the small-view-field camera with the star-sensitive camera through an optimal estimation algorithm, S4, setting limiting conditions of the estimation algorithm in the step S3, including limiting the estimated values and timing the estimation algorithm, wherein the step S2 is specifically that the star-based small-view-field camera transmits image information to the star-sensitive camera in real time, and the star-sensitive camera is used for identifying images through a star identification algorithm after the star-sensitive camera loads optical system parameters of the small-view-field camera, and simultaneously giving vector coordinates of the star in the star-sensitive measurement coordinate system and the star-sensitive measurement coordinate system in the star-sensitive measurement coordinate system respectively: wherein Is a star vector under an inertial system stored in a star-sensitive star database, Through satellite inertia quaternion Calculating to obtain the vector coordinates of the star in the small field of view camera measurement coordinate system Can be directly obtained by extracting star images shot by the space-based small-view-field camera by star sensitivity through using a mature star recognition algorithm, The step S3 further comprises the steps of S31, establishing a reference plane perpendicular to the star-sensitive measurement plane, wherein the base vector of the reference plane is H (k), S32, establishing an observed quantity S33, calculating the measurement reference deviation angle of the small-view-field camera and the star sensor Wherein For measuring the rolling deviation angle of the small-field camera and the star sensitivity, For measuring pitch offset angle of small field camera and star sensitivity, Measuring a yaw offset angle for a small field-of-view camera and a star sensor; Wherein, the Is a matrix Is a matrix of inverse of (a).
2. The astronomical calibration method for synchronizing a small-view-field camera with a star-sensitive measurement reference is characterized in that the step S1 further comprises the following steps of S11, utilizing the pointing capability of any inertial space of a satellite, enabling the optical axis of the small-view-field camera on the satellite to point to a desired star in the space, enabling the three-axis attitude of the satellite to scan at a constant speed and in a constant angle range during the period, driving the optical axis of the small-view-field camera on the star as the center to scan a cross-shaped track, acquiring a desired star image in real time through measurement information of the small-view-field camera, S12, capturing a space region corresponding to the field of view of the star-sensitive synchronous exposure itself when the small-view-field camera shoots and scans the desired star, and acquiring satellite inertial quaternion under a star-sensitive measurement coordinate system 。
3. The astronomical calibration method for synchronizing a small field of view camera with a star sensor measurement reference of claim 2, wherein the star sensor sends an internal exposure signal to the space-based small field of view camera in real time to synchronize the falling edges of the two.
4. The astronomical calibration method for synchronizing a small-field camera with a star sensor measurement reference of claim 1, wherein a high-speed communication interface is arranged between the small-field camera and the star sensor.
5. The astronomical calibration method for synchronizing a small-view camera with a star sensor measurement reference according to claim 1 is characterized in that step S4 is specifically implemented by performing amplitude limiting processing on estimated values of measurement deviation angles of the small-view camera and the star sensor, wherein the amplitude is 0.1/57.3rad, setting a counter for an estimation algorithm of step S3, starting timing the counter when the optimal estimation algorithm is started, taking an output value of the optimal estimation algorithm after 50S of counting as the measurement reference deviation angle of the small-view camera and the star sensor, exiting the algorithm at the moment and resetting the counter.

Description

Astronomical calibration method for synchronizing small-view-field camera and star-sensitive measurement reference Technical Field The invention relates to a satellite attitude determination and reference identification technology, in particular to an astronomical calibration method for synchronizing a space-based small-view-field camera with a star-sensitive period measurement reference. Background The space safety satellite needs to obtain the position and posture information of the target satellite, and in the process of acquiring the posture information, the measurement reference error of the star sensor relative to the satellite body coordinate system and the measurement reference error of the tracking single machine (space-based small-field camera) relative to the satellite body coordinate system are involved. Both the star-sensitive and space-based small-view cameras are high-precision optical instruments, and various error sources exist, such as installation errors, thermal deformation errors, optical system imaging errors, machining assembly errors, optical axis instability, CCD noise, dark current, response non-uniformity, electronic circuit noise, calibration errors and the like, so that error calibration compensation is required to obtain high-precision angle measurement. At present, the calibration of the star sensor and the small-view field camera is generally performed by using ground calibration test equipment, but because a laboratory and a measurement and control system corresponding to the ground calibration are quite complex, the environment of the ground calibration is expensive, and various space environments of the satellite in-orbit operation cannot be completely and truly simulated. Secondly, as the working time of the satellite in the irradiation environment increases, the aberration of an optical system in the star-sensitive and space-based small-view-field camera increases, the structure deforms and the like, so that various ground calibration parameters of the star-sensitive and small-view-field camera change. When the star-sensitive and space-based small-field-of-view camera is actually measuring on-orbit, the method is influenced by various factors such as installation errors, calibration precision and the like, the measurement errors are increased, and the measurement precision of the installation errors and the calibration precision is reduced; Moreover, the space-based small-view-field camera is generally limited to the size of the view field, satellite inertial quaternion information under a measurement system cannot be directly output, and in the attitude pointing control of a space safety satellite, satellite attitude determination is often carried out by using the measurement information of the space-based small-view-field camera and the space-based small-view-field camera, so that the installation deviation between the space-based small-view-field camera and the space-based small-view-field camera needs to be calibrated and reflected to high-precision attitude determination. Disclosure of Invention The invention aims to solve the problems of large error and measurement precision of the existing star-sensitive and space-based small-view-field camera calibration method. In order to achieve the above purpose, the invention provides an astronomical calibration method for synchronizing a small-view-field camera and a star-sensitive measurement reference, which comprises the following steps: S1, adopting a space-based small-view-field camera and a star-sensitive camera to simultaneously expose and scan a space area corresponding to each view field, wherein an expected star is near the center of the view field of the space-based small-view-field camera, and acquiring a satellite inertia quaternion under a star-sensitive measurement coordinate system and an expected star image under the small-view-field camera measurement coordinate system; S2, the star sensor calculates star vector coordinates of the same star in a star sensor measurement coordinate system and a space-based small view field camera measurement coordinate system according to the measurement information of the space-based small view field camera and the star sensor; s3, calculating estimated values of measurement deviation angles of the space-based small-view camera and the star sensor through an optimal estimation algorithm; S4, setting limiting conditions of the estimation algorithm in the step S3, wherein the limiting conditions comprise limiting amplitude of the estimation value and timing of the estimation algorithm. Wherein, the step S1 further comprises the following steps: S11, utilizing the pointing capability of any inertial space of a satellite, enabling an optical axis of a space-based small-view field camera on the satellite to point to a desired star in the space, and during the period, scanning the satellite in a triaxial attitude with a constant speed and a constant angle range, so that the field