阅读说明：本技术 一种亚角秒星敏感器地面精度测试验证系统及方法 (sub-arc-second star sensor ground precision test verification system and method ) 是由 郑然� 钟俊 程会艳 武延鹏 张腾飞 赵亚芹 王晓燕 李玉明 隋杰 田玉松 曾峥 于 2019-08-14 设计创作，主要内容包括：本发明涉及一种亚角秒星敏感器地面精度测试验证系统及方法,属于卫星姿态控制技术领域。该方法可对产品地面静态及动态条件下优于0.1″精度进行测试及验证,解决了星敏感器产品难以通过试验对亚角秒级精度进行有效测试及验证的问题。该方法易于实现,使用方便,可有效节省试验成本,解放人力资源。该方法不仅可实现单个探头亚角秒精度测试与验证,同时,可对多个探头融合后实现亚角秒精度进行测试及验证,可适应众多亚角秒精度产品类型,具有很好的推广应用价值,该方法为一种切实可行、实现代价低且便于使用的甚高精度星敏感器精度测试与验证方法。(the invention relates to a sub-arc second star sensor ground precision test verification system and a sub-arc second star sensor ground precision test verification method, and belongs to the technical field of satellite attitude control. The method can test and verify the precision of the product better than 0.1' under the static and dynamic conditions on the ground, and solves the problem that the star sensor product is difficult to effectively test and verify the sub-arc second-level precision through tests. The method is easy to realize and convenient to use, can effectively save the test cost and liberate human resources. The method can realize the sub-arc second precision test and verification of a single probe, can realize the sub-arc second precision test and verification after a plurality of probes are fused, can adapt to a plurality of sub-arc second precision product types, has good popularization and application values, and is a very high precision star sensor precision test and verification method which is practical, low in realization cost and convenient to use.)

1. a sub-arc second star sensor ground precision test verification system is characterized in that: the system comprises an air-floating optical platform, a multi-star simulator, a light source and a product support;

the multi-star simulator comprises a two-dimensional motion platform for controlling the movement of the reticle, and the two-dimensional motion platform can realize the movement of the reticle in two directions vertical to the direction of the optical axis of the image plane;

The focal plane of the multi-star simulator can move orthogonally in two directions perpendicular to the optical axis direction, so that the change of an included angle between the probes of the star sensor is simulated and measured;

the light source is a generator light source capable of simulating any star-class spectrum;

The multi-star simulator, the light source and the product support are all placed on the air-floating optical platform, the sub-angular-second star sensor to be detected is installed on the air-floating optical platform through the product support, the light source can simulate infinite star parallel light beams to enter a view field of the sub-angular-second star sensor to be detected after passing through the multi-star simulator, and imaging is carried out on a detector of the sub-angular-second star sensor to be detected.

2. the sub-arc-second star sensor ground precision testing and verifying system according to claim 1, characterized in that: the number of the multi-star simulators is consistent with that of the probes of the sub-arc-second star sensor to be detected.

3. the sub-arc-second star sensor ground precision testing and verifying system according to claim 1, characterized in that: the image plane moving precision of the multi-star simulator is better than d, d is tan theta multiplied by f, theta is the measuring precision, and f is the focal length of the multi-star simulator; the image plane moving range is larger than +/-f multiplied by tan (2 omega/2), wherein 2 omega is the field angle of the product, and f is the focal length of the multi-star simulator.

4. The sub-arc-second star sensor ground precision testing and verifying system according to claim 1, characterized in that: the optical parameters of the multi-star simulator comprise a field of view, an aperture and an exit pupil distance, wherein the field of view needs to be ensured that the field of view of the multi-star simulator can cover the field of view of a product to be tested; the aperture size ensures that the exit pupil of the multi-star simulator is superposed with the optical system of the product; the exit pupil distance needs to ensure that the entrance pupil of the product to be measured coincides with the exit pupil of the multi-star simulator.

5. the sub-arc-second star sensor ground precision testing and verifying system according to claim 1, characterized in that: and the two directions vertical to the optical axis direction of the image surface are the X-axis direction and the Y-axis direction.

6. the sub-arc-second star sensor ground precision testing and verifying system according to claim 1, characterized in that: the method is characterized in that a translation structure of a two-dimensional motion platform is realized by a precise mechanical translation mechanism or an air-flotation translation mechanism, a multi-star simulator is controlled to move at different speeds, the precision of products at different angular speeds is tested and verified, meanwhile, the motion trail of a reticle is controlled, sinusoidal motion is realized, the condition that the two included angles of product probes have periodic variation due to the influence of temperature when the products work in an orbit is simulated, and the precision of the products after fusion is tested and verified when the two included angles of the product probes have periodic variation.

7. A sub-arc second star sensor ground precision test verification method is characterized by comprising the following steps:

(1) Mounting the sub-arc-second star sensor product to be detected on the air-floating optical platform through a product bracket, and enabling the air-floating optical platform to be in a stable state;

(2) controlling the working temperature of a reticle of the multi-star simulator to be constant at 20 ℃;

(3) Enabling the reticles to seek zero through a two-dimensional motion platform, and enabling all reticles to be in zero positions;

(4) starting a light source, acquiring an imaging image of a product to be detected, and adjusting the brightness of the light source according to the acquired imaging image of the product to be detected;

(5) The parallelism of the parallel light beams of the fixed stars, which are emitted by the light source after passing through the multi-star simulator, is tested, and the parallelism of the multi-star simulator is adjusted according to the test result, so that the parallelism of the parallel light beams of the fixed stars, which are emitted by the multi-star simulator, is better than 5';

(6) electrifying the product to be tested, and ensuring that the electrifying time of the product to be tested is not less than 8 h;

(7) Setting the movement speed of a reticle, enabling the reticle to move at a constant speed along the X direction, and recording the position variation of star points, the output attitude data of a star sensor and the movement distance value of the multi-star simulator under different distances of the image surface movement of the multi-star simulator in the movement process;

(8) setting the movement speed of a reticle, enabling the reticle to move at a constant speed along the Y direction, and recording the position variation of star points, the output attitude data of a star sensor and the movement distance value of the multi-star simulator under different distances of image surface movement of the multi-star simulator in the movement process;

(9) And (5) performing statistical analysis on the data recorded in the steps (7) and (8) to obtain a precision test result of the product to be tested.

8. A sub-arc second star sensor ground precision test verification method is characterized by comprising the following steps:

(1) mounting the sub-arc-second star sensor product to be detected on the air-floating optical platform through a product bracket, and enabling the air-floating optical platform to be in a stable state;

(2) Controlling the working temperature of a reticle of the multi-star simulator to be constant at 20 ℃;

(3) enabling the reticles to seek zero through a two-dimensional motion platform, and enabling all reticles to be in zero positions;

(4) starting a light source, acquiring an imaging image of a product to be detected, and adjusting the brightness of the light source according to the acquired imaging image of the product to be detected;

(5) the parallelism of the parallel light beams of the fixed stars, which are emitted by the light source after passing through the multi-star simulator, is tested, and the parallelism of the multi-star simulator is adjusted according to the test result, so that the parallelism of the parallel light beams of the fixed stars, which are emitted by the multi-star simulator, is better than 5';

(6) electrifying a product to be tested, confirming a reticle of the multi-star simulator according to the output attitude data of the star sensor, and ensuring that the installation included angle of a corresponding probe of the installed reticle is consistent with the installation included angle to be tested; if the two are not consistent, the reticle needs to be replaced, and the power-on time of the product to be tested is not less than 8 h;

(7) setting all the corresponding reticles of the probes to move at the same constant speed along the X direction, and recording the position variation of star points, the output attitude data of the star sensor and the moving distance value of the multi-star simulator under different distances of the moving image surface of the multi-star simulator in the moving process;

(8) Setting all the corresponding reticles of the probes to move at the same constant speed in the Y direction, and recording the position variation of star points, the output attitude data of the star sensor and the moving distance value of the multi-star simulator under different distances of the moving image surface of the multi-star simulator in the moving process;

(9) and (5) performing statistical analysis on the data recorded in the steps (7) and (8) to obtain a precision test result of the product to be tested.

9. the method for testing and verifying the ground precision of the sub-arc-second star sensor according to claim 8, wherein the method comprises the following steps: in the step (9), the method for testing the precision of the product to be tested comprises the following steps: the method comprises the following steps of utilizing test data to carry out product attitude measurement accuracy analysis, taking action position variation calculated according to image surface movement distance of the multi-star simulator as a star point position variation true value, correspondingly calculating attitude variation of each probe of the star sensor according to the variation true value as an attitude variation true value, taking attitude data of each probe collected in real time as a measured value, and counting errors between attitude measured values and true values to obtain the attitude measurement accuracy of the star sensor.

10. the method for testing and verifying the ground precision of the sub-arc-second star sensor according to claim 8, wherein the method comprises the following steps: in the step (8), if the product probes have periodic change of included angles due to the influence of temperature when the multi-probe star sensor works in the orbit, one probe corresponding to the reticle is set to periodically move according to a certain movement period and amplitude, the other reticles are set to move at a constant speed, and the star point position change amount, the star sensor output attitude data and the multi-star simulator movement distance value under different distances of the multi-star simulator image surface movement are recorded in the movement process.

Technical Field

The invention relates to a ground precision test verification system and method for a star sensor, and belongs to the technical field of satellite attitude control.

background

the star sensor obtains a star observation vector by imaging a space star, the direction of an optical axis of the star sensor in an inertial space is determined by adopting a star map matching method, and the satellite attitude is determined by utilizing the conversion relation between a star sensor body coordinate system and a satellite attitude coordinate system.

in recent years, with the continuous expansion of the application field of satellites, particularly high-resolution earth observation and astronomical observation tasks, higher precision requirements are provided for the control precision and stability of the satellites. The star sensor which is divided from the aspect of attitude measurement precision and has the precision of 10' magnitude belongs to the conventional precision star sensor; the precision is 3-5' magnitude, and the star sensor belongs to a high-precision star sensor. At present, the mainstream products at home and abroad belong to the two levels, the development mechanisms are more, and the product models are more. With the requirement of high-precision positioning precision of satellites, sub-arc second precision star sensors with precision superior to 1' are being developed by relevant units.

at present, the precision test of domestic and foreign star sensor products is mainly carried out by two methods, namely simulation test and field star observation, which are respectively as follows:

1) Simulation test

the star sensor precision is analyzed and verified on the ground through simulation at present, star maps under different conditions are simulated mainly according to product design parameters, then the simulated star maps are processed by using a software algorithm (consistent with the software algorithm on the product) to obtain star sensor attitude data under different conditions, and finally the attitude data is analyzed and processed to give the star sensor measurement precision under different conditions; for the multi-probe star sensor, a simulation tool can be used for carrying out simulation test and verification on the estimation precision of the drift deviation of the mounting array between the probes.

2) Star observation test

The star observation test is mainly characterized in that attitude data of the star sensor at different angular speeds within a period of time are collected by controlling the rotary table, and then the attitude data are processed by using an accuracy analysis method to obtain the measurement accuracy of the star sensor at different angular speeds. The measurement errors of the star sensor obtained by the existing star observation test mainly comprise two parts, namely a high-frequency error of the star sensor and a related low-frequency error of a view field.

for the star sensor product, the main means for precision test and verification is the field star observation test. However, the method is greatly influenced by the observation condition of the external field, especially the atmospheric seeing of the observation station. For the sub-arc second precision star sensor, the requirement for higher precision is put forward for the external field observation condition. Through analyzing the relevant test data of the domestic astronomical observatory, the average seeing degree of the Yunnan Lijiang astronomical observation station with the best domestic observation condition is about 0.7 ', the average seeing degree is basically maintained below 0.9' throughout the year, and the test method has the basic condition of sub-arc second-level precision product test. However, the satellite viewing conditions of the current Yunnan Lijiang astronomical observation station have the following problems:

(1) the observation condition is relatively simple, no matched test equipment exists, and the dynamic precision test of the product cannot be carried out;

(2) the climate is changeable, most of the time is rainy season, the number of observable days is small, and the product precision test in the delivery time is difficult to realize;

(3) the observation cost is high, each product needs to go to a Lijiang astronomical observation station for precision test and verification, and a great deal of energy, material resources, manpower and other resources are needed.

Disclosure of Invention

the technical problem to be solved by the invention is as follows: the method can test and verify the precision superior to 0.1' under the static and dynamic conditions of the product ground, and solves the problem that the star sensor product is difficult to effectively test and verify the sub-arc second-level precision through tests. The method is easy to realize and convenient to use, can effectively save the test cost and liberate human resources. The method can realize the sub-arc second precision test and verification of a single probe, can realize the sub-arc second precision test and verification after a plurality of probes are fused, can adapt to a plurality of sub-arc second precision product types, has good popularization and application values, and is a very high precision star sensor precision test and verification method which is practical, low in realization cost and convenient to use.

the technical solution of the invention is as follows:

a sub-arc second star sensor ground precision test verification system comprises an air-floating optical platform, a plurality of multi-star simulators, a light source and a product support;

the number of the multi-star simulators is consistent with that of the probes of the sub-arc-second star sensor to be detected; the image plane moving precision of the multi-star simulator is better than d, d is tan theta multiplied by f, theta is the measuring precision, and f is the focal length of the multi-star simulator; the image plane moving range needs to be larger than +/-f multiplied by tan (2 omega/2), wherein 2 omega is the field angle of the product, and f is the focal length of the multi-star simulator. The optical parameters of the multi-star simulator mainly comprise parameters such as a field of view, an aperture and an exit pupil distance. The field of view size needs to ensure that the field of view of the multi-star simulator can cover the field of view of the product to be tested; the aperture size ensures that the exit pupil of the multi-star simulator is superposed with the optical system of the product; the exit pupil distance needs to ensure that the entrance pupil of the product to be measured is coincident with the exit pupil of the multi-star simulator;

The multi-satellite simulator comprises a two-dimensional motion platform for controlling the movement of the reticle, and the two-dimensional motion platform can realize the high-precision movement of the reticle in two directions (an X axis and a Y axis) vertical to the optical axis direction of an image plane; the high-precision translation structure of the two-dimensional motion platform can be realized by a precise mechanical translation mechanism or an air floatation translation mechanism and the like. The method can test and verify the precision of products at different angular speeds by controlling the multi-star simulator to move at different speeds, can control the motion track of the reticle, and can simulate the condition that the product probes have periodic change at two included angles due to the influence of temperature and the like when the product is in orbit work by setting the motion period and amplitude to realize sinusoidal motion, and test and verify the precision of the fused products when the product probes have periodic change at two included angles.

the light source is a generator light source capable of simulating any star light spectrum;

the focal plane of the multi-star simulator can orthogonally move (X axis and Y axis) in two directions perpendicular to the optical axis direction, so that the change of an included angle between the star sensor probes is simulated and measured;

The multi-star simulator comprises a plurality of multi-star simulators, a light source and a product support, wherein the multi-star simulator comprises a plurality of light sources, the light sources and a product support, the multi-star simulator comprises a plurality of light sources, the light sources and the product support are all arranged on an air-floating optical platform, the sub-arc-second star sensor to be detected is installed on the air-floating optical platform through the product support, the light sources can simulate infinite star parallel light beams to enter a view field of the sub-arc-second star sensor to be detected after.

A sub-angle second star sensor ground precision test verification method, the multi-probe very high precision star sensor carries on the information fusion processing based on the star point information in the field of view of multiple probes, in order to further promote the product precision, its multiple probes realize the index is superior to 0.6 "(3 sigma) after fusing, the single probe realizes the index is superior to 1" (3 sigma), it is very high precision, high dynamic and high dynamic performance, mainly apply to the remote sensing satellite and high-resolution earth observation satellite, this method passes the control multi-star simulator reticle movement, realize the product precision test and verification under the small dynamic condition of different fields of view; simulation of fixed stars in different included angles and different view fields of a plurality of probes (at most 3 probes) is realized by replacing the reticle of the multi-star simulator, and precision test and verification after fusion of the probes are realized;

The method comprises the following steps:

(1) mounting the sub-arc-second star sensor product to be detected on the air-floating optical platform through a product bracket, and enabling the air-floating optical platform to be in a stable state;

(2) controlling the working temperature of a reticle of the multi-star simulator to be constant at 20 ℃;

(3) Enabling the reticles to seek zero through a two-dimensional motion platform, and enabling all reticles to be in zero positions;

(4) Starting a light source, acquiring an imaging image of a product to be detected, and adjusting the brightness of the light source according to the acquired imaging image of the product to be detected;

(5) the parallelism of the parallel light beams of the fixed stars, which are emitted by the light source after passing through the multi-star simulator, is tested, and the parallelism of the multi-star simulator is adjusted according to the test result, so that the parallelism of the parallel light beams of the fixed stars, which are emitted by the multi-star simulator, is better than 5';

(6) electrifying a product to be tested, if the precision of the fused multi-probe star sensor needs to be tested and verified, confirming a reticle of the multi-probe simulator according to output attitude data of the star sensor, and ensuring that the installation included angle of a corresponding probe of the installed reticle is consistent with the installation included angle to be tested; if the two are not consistent, the reticle needs to be replaced, and the power-on time of the product to be tested is not less than 8 h;

(7) Setting the movement speed of a reticle, enabling the reticle to move at a constant speed along the X direction, and recording the position variation of star points, the output attitude data of a star sensor and the movement distance value of the multi-star simulator under different distances of the image surface movement of the multi-star simulator in the movement process;

if the accuracy of the fused multiple probes (at most 3 probes) needs to be tested and verified, setting that all the probes move at the same constant speed according to the X direction, and recording the star point position variation, the star sensor output attitude data and the multi-star simulator moving distance value of the multi-star simulator when the image surface of the multi-star simulator moves at different distances in the moving process;

(8) Setting the movement speed of a reticle, enabling the reticle to move at a constant speed along the Y direction, and recording the position variation of star points, the output attitude data of a star sensor and the movement distance value of the multi-star simulator under different distances of image surface movement of the multi-star simulator in the movement process;

If the accuracy of the fused multiple probes (at most 3 probes) needs to be tested and verified, setting that all the probes move at the same constant speed in the Y direction corresponding to the reticle, and recording the position variation of star points, the output attitude data of the star sensor and the moving distance value of the multi-star simulator when the image surface of the multi-star simulator moves at different distances in the moving process;

If the product probe included angles are periodically changed due to the influence of temperature and the like when the multi-probe star sensor works in an orbit, testing and verifying the precision after product fusion, setting one of the probes to periodically move according to a certain movement period and amplitude corresponding to a reticle, setting other reticles to move at a constant speed, and recording the position change quantity of star points, the output attitude data of the star sensor and the movement distance value of the multi-star simulator under different image surface movement distances of the multi-star simulator in the movement process;

(9) and collecting data of the multi-star simulator and the star sensor under each working condition for statistical analysis, and giving a precision test result of the product to be tested.

and taking the action position variation calculated according to the image plane movement distance of the multi-star simulator as a true value of star point position variation, correspondingly calculating the attitude variation of each probe of the star sensor according to the true value of the variation as a true value of attitude variation, taking attitude data of each probe collected in real time as a measured value, and counting errors between the attitude measured value and the true value to obtain the attitude measurement precision of the star sensor.

advantageous effects

(1) a set of method for testing and verifying the sub-arc second-level star sensor product precision in a laboratory is provided, and the problem that the sub-arc second-level precision of the product cannot be tested and verified on the ground is solved;

(2) the test method provides that the product precision test and verification under the small dynamic conditions of different fields of view are realized by controlling the movement of a plurality of multi-star simulator reticles;

(3) the method can test and verify the sub-arc second-level precision of a single probe and a plurality of probes;

(4) the test method firstly provides that the star simulation in different included angles and different view fields of a plurality of probes is realized by replacing the reticle of the multi-star simulator, is different from the traditional method of carrying out precision test and verification by designing different product supports, and is simple and easy to realize.

Drawings

FIG. 1 is a schematic view of a verification system according to the present invention.

Detailed Description

The specific implementation mode of the sub-arc second star sensor ground precision test verification method provided by the invention is as follows:

(1) carrying out precision test and verification test system scheme design;

(2) according to the requirement that the multi-star simulator needs to realize important functions and indexes, a two-dimensional motion platform which meets the requirement and is required by high-precision image surface movement of the multi-star simulator, a matching reticle and the multi-star simulator is developed;

(3) Designing and processing structural components such as a support of the star sensor product to be tested, a mounting support of the multi-star simulator and the like according to the star sensor product to be tested, the multi-star simulator appearance dimension interface and the like;

(4) according to the design of a system scheme, the layout of a precision test and verification test system is given, the dimensional performance requirement of an optical platform required by the test system is given, and the optical platform required by the placement of a test component is developed;

(5) According to the environment design and requirements of the precision testing system, carrying out precision testing and the implementation of laboratory environment conditions required by the verification testing system;

(6) after all the equipment and the components are ready, debugging, testing and verifying the functional performance of the precision testing and verifying system by using the product to be tested;

(7) Performing precision testing and verification testing according to the precision testing and verification testing scheme;

(8) firstly, starting environmental condition control such as the temperature, the humidity and the illumination of a darkroom of a test system, starting an optical platform control mechanism, and mounting one or more star sensor products to be tested on a product support after an optical platform is stabilized;

(9) starting a constant temperature box, controlling the working temperature of the reticle to be constant at 20 ℃, searching zero for the reticle through a two-dimensional motion platform control mechanism, and controlling all the reticles to be at zero positions;

(10) the light source brightness, uniformity, light pipe parallelism and other performances of the multi-star simulator are confirmed;

(11) electrifying the star sensor to be tested, and starting a precision test and verification test after the normal working time of a star sensor product is more than 8 hours;

(12) Setting the movement speed of a reticle, controlling the reticle to move at constant speed along the X direction and the Y direction respectively, and recording the position variation of star points, the output attitude data of a star sensor and the movement distance value of the multi-star simulator under different distances of image surface movement of the multi-star simulator in the movement process;

(13) If the precision of a fused multi-star simulator is required to be tested and verified, all the corresponding reticles of the probes are set to move at the same constant speed in the same direction X direction/Y direction, when the influence of temperature and the like on the product in the rail working process is required to be simulated to cause the periodic change of the included angles of every two product probes, one of the corresponding reticles of the probes is set to periodically move according to a certain movement period and amplitude, the other reticles are set to move at a constant speed, and the position change of star points, the output attitude data of the star sensors and the moving distance value of the multi-star simulator under the condition that the image surface of the multi-star simulator moves at different distances are recorded in the moving process;

(14) and collecting data of the multi-star simulator and the star sensor under each working condition for statistical analysis, and giving a precision test result of the product to be tested.