CN108490714B

CN108490714B - Star sensor lens hood

Info

Publication number: CN108490714B
Application number: CN201810240718.6A
Authority: CN
Inventors: 李保权
Original assignee: National Space Science Center of CAS
Current assignee: National Space Science Center of CAS
Priority date: 2018-03-22
Filing date: 2018-03-22
Publication date: 2020-12-11
Anticipated expiration: 2038-03-22
Also published as: CN108490714A

Abstract

The invention discloses a star sensor light shield which is formed by split assembly of an installation shield (1) and a beam limiting shield (2); a knife edge light-blocking ring at the butt joint part of the installation cover (1) and the beam limiting cover (2) is a first knife edge light-blocking ring (4); the knife edge light-blocking ring at the butt joint of the beam limiting cover (2) and the mounting cover (1) is a second knife edge light-blocking ring (5); and the surfaces of the first knife edge light-blocking ring (4) opposite to the second knife edge light-blocking ring (5) are respectively provided with extinction grains. The invention adds the extinction lines with special structures on the surface of the key light blocking ring of the traditional light shield, and can improve the inhibition effect of stray light by orders of magnitude under the condition of not increasing the volume size of the light shield. The novel light shield structure can greatly improve the observation sensitivity and the measurement precision of the star sensor under the condition of not increasing the resource demand.

Description

Star sensor lens hood

Technical Field

The invention relates to the field of stray light suppression of camera systems, in particular to a satellite star sensor light shield with strict requirements on stray light suppression outside a field of view, and particularly relates to a star sensor light shield.

Background

The star sensor is used for measuring the attitude of the spacecraft by imaging fixed stars on the celestial sphere and calculating a transformation matrix of the fixed stars in a camera coordinate system and a geocentric coordinate system. The imaging object of the star sensor is a fixed star, the signal intensity is weak, and the star sensor is easily influenced by strong light sources such as direct sunlight or moon earth albedo in practical application, so that the performance of the star sensor is reduced in serious cases, and even the star sensor cannot work. Therefore, the star sensor is basically provided with a light shield for inhibiting or eliminating the influence of stray light of the sun, the earth and the moon, and the observation range of the whole celestial sphere is expanded as much as possible.

At present, a round beam limiting cover or a conical light shield is generally adopted internationally, in order to increase the light shielding effect and limit the field angle, light blocking rings are added inside the round beam limiting cover and the conical light shield, the number and the positions of the light blocking rings depend on the size of a star sensor lens and the size of the field angle of the star sensor, and the suppression effect is in direct proportion to the length of the light shield. In general, suppression of stray lightThe better the result, the longer the shade will be, if the required out-of-view solar suppression ratio reaches 10^-9The length of the light shield can approach or exceed 200mm, so the light shield is bulky and heavy, which conflicts with valuable resource constraints on the spacecraft. In order to reduce the size of the light shield, on the basis of the structural design of the traditional light shield, super black paint is generally required to be sprayed on the inner wall of the light shield to reduce diffuse reflection light rays or refrigerate a CCD (charge coupled device) of the star sensor to enhance the signal-to-noise ratio of a star point image.

Disclosure of Invention

The invention aims to overcome the defect of the traditional light shield structure in the stray light inhibition effect, and the light-eliminating stripes with special structures are added on the surface of the light blocking ring based on the traditional light shield structure, so that the stray light inhibition effect can be improved by orders of magnitude under the condition of not increasing the volume size of the light shield, the observation sensitivity and the measurement precision of the star sensor can be greatly improved by the novel light shield structure under the condition of not increasing the resource requirement, and the stray light inhibition effect can be improved or improved by orders of magnitude.

In order to achieve the aim, the invention provides a star sensor light shield which is formed by assembling a mounting cover 1 and a beam limiting cover 2 in a split mode; a knife edge light-blocking ring at the joint of the installation cover 1 and the beam limiting cover 2 is a first knife edge light-blocking ring 4; the knife edge light-blocking ring at the joint of the beam limiting cover 2 and the mounting cover 1 is a second knife edge light-blocking ring 5; and the surfaces of the first knife edge light-blocking ring 4 opposite to the second knife edge light-blocking ring 5 are respectively provided with extinction grains.

As a modification of the above device, the mounting cover 1 and the beam limiting cover 2 are fixed by screw threads.

As a modification of the above device, the mounting cover 1 is externally provided with a reinforcing rib 3.

As a modification of the above device, the beam limiting cover 2 has a cylindrical structure.

As an improvement of the device, the extinction lines are of a sawtooth annular concentric structure.

As an improvement of the device, the radial widths of the protrusions and the grooves in the sawtooth structure of the extinction groove are consistent.

As an improvement of the device, the height of the protrusions of the extinction grooves is 0.5-3 times of the radial width of the grooves.

As an improvement of the device, the top end of the convex part of the extinction vein is in a knife edge shape, and the knife edge section deviates from the centers of the first knife edge light-blocking ring 4 and the second knife edge light-blocking ring 5.

As an improvement of the device, the slope angle of the protrusions of the extinction lines is between 20 and 70 degrees.

As a modification of the above arrangement, the mounting cap 1 and the beam limiting cap 2 are coaxial.

The invention has the advantages that:

1. the invention adds the extinction lines with special structures on the surface of the key light blocking ring of the traditional light shield, and can improve the inhibition effect of stray light by orders of magnitude under the condition of not increasing the volume size of the light shield;

2. the novel light shield structure can greatly improve the observation sensitivity and the measurement precision of the star sensor under the condition of not increasing the resource requirement;

3. the star sensor light shield has a two-body structure of the installation shield and the beam limiting shield, reduces the processing difficulty of the light shield, is beneficial to the coaxial control and the spacing precision control of the light blocking rings in the light shield, and enhances the integral inhibition performance of the light shield on stray light.

Drawings

FIG. 1 is a schematic view of the overall structure of the star sensor light shield of the present invention;

FIG. 2 is a schematic view of a mounting cup for the light shield of the star sensor of the present invention;

FIG. 3 is an overall cross-sectional view of the light shield of the present invention;

fig. 4 is a partially enlarged view of a portion a of fig. 3.

Reference symbols of the drawings

1. Mounting cover 2, beam limiting cover 3 and reinforcing ribs

4. First knife edge light blocking ring 5 and second knife edge light blocking ring

Detailed Description

The invention will now be further described with reference to the accompanying drawings.

As shown in fig. 1, the star sensor light shield of the present invention is assembled by a mounting cover 1 and a beam limiting cover 2 separately.

As shown in fig. 2, the mounting cover 1 has a reinforcing rib 3 outside for reinforcing the strength of the light shield, and the knife edge light-blocking ring at the joint with the beam limiting cover 2 in the mounting cover 1 is a first knife edge light-blocking ring 4.

As shown in fig. 1, the beam limiting cover 2 is a cylindrical structure, and a knife edge light-blocking ring at the joint between the beam limiting cover 2 and the mounting cover 1 is a second knife edge light-blocking ring 5; and the surfaces of the first knife edge light-blocking ring 4 opposite to the second knife edge light-blocking ring 5 are respectively provided with extinction lines for limiting the view field and weakening stray light reflection. The beam limiting cover 2 and the mounting cover 1 are fixed through threads.

The components of the star sensor light shield are further described below.

Compared with the traditional light shield, the light shield of the star sensor is formed by the mounting cover 1 and the beam limiting cover 2 integrally, and the light shield is characterized in that special-structure light eliminating lines which can be processed and realized are added on a key knife edge light blocking ring, so that the inhibition effect on stray light is greatly enhanced. As shown in fig. 3 and 4, the extinction vein is of a sawtooth annular structure, the protrusions and the grooves of the sawtooth structure are uniformly distributed on the surface of the light blocking ring, the radial widths of the grooves and the protrusions of the extinction vein are consistent or nearly consistent, and the radial widths are kept unchanged; the extinction pattern bulges are cut into a knife edge shape. The angle of the knife edge slope is between 20 and 70 degrees, the top end of the convex part of the extinction line is in a knife edge shape, and the knife edge section deviates from the center of the first knife edge light-blocking ring 4 and the center of the second knife edge light-blocking ring 5. The height of the extinction pattern convex structure is 0.5-3 times of the radial width of the groove.

The light shield of the invention is composed of an installation cover 1 and a beam limiting cover 2, and the extinction grains are processed on only one surface of the knife edge light-blocking ring at the corresponding part of the installation cover 1 and the beam limiting cover 2. The mounting cover 1 and the beam limiting cover 2 are fixed through thread coupling, and coaxiality of the two bodies is guaranteed.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. The star sensor light shield is characterized by being assembled by a mounting cover (1) and a beam limiting cover (2) in a split mode; a knife edge light-blocking ring at the butt joint part of the installation cover (1) and the beam limiting cover (2) is a first knife edge light-blocking ring (4); the knife edge light-blocking ring at the butt joint of the beam limiting cover (2) and the mounting cover (1) is a second knife edge light-blocking ring (5); the surfaces of the first knife edge light-blocking ring (4) opposite to the second knife edge light-blocking ring (5) are respectively provided with extinction grains;

the extinction lines are of a saw-toothed annular concentric structure; the radial widths of the protrusions and the grooves in the sawtooth structure of the extinction lines are consistent; the top end of the convex part of the extinction line is in a knife edge shape, and the knife edge section deviates from the centers of the first knife edge light-blocking ring (4) and the second knife edge light-blocking ring (5).

2. The star sensor light shield according to claim 1, wherein the mounting shield (1) and the beam limiting shield (2) are fixed by screw thread coupling.

3. The star sensor light shield according to claim 1, characterized in that a reinforcing rib (3) is provided outside the mounting cover (1).

4. The star sensor light shield according to claim 1, characterized in that the beam limiting shield (2) is of a cylindrical structure.

5. The star sensor light shield according to claim 1, wherein the bump height of the extinction mark is 0.5 to 3 times the radial width of the groove.

6. The star sensor light shield according to claim 1, wherein the raised slope angle of the extinction mark is between 20-70 degrees.

7. The star sensor light shield according to claim 1, characterized in that the mounting shield (1) and the beam limiting shield (2) are coaxial.