Large-size focal plane coupling reflex mirror integrated structure of space camera and coupling assembly method of large-size focal plane coupling reflex mirror integrated structure

Abstract

The invention relates to a space camera large-size focal plane coupling reflex mirror integrated structure and a coupling assembly method thereof, and relates to the technical field of aerospace optical remote sensing camera focal plane development. The invention discloses a large-size focal plane coupling reflex mirror integrated structure of a space camera. The integrated structure comprises a focal plane assembly, a reflex mirror assembly and a trimming gasket, the reflex mirror assembly is arranged at a light inlet at the upper part of the focal plane assembly; a trimming gasket is arranged at the joint of the focal plane assembly and the reflex mirror assembly, and the trimming gasket is used for ensuring the assembly precision between the focal plane assembly and the reflex mirror assembly through trimming and grinding. According to the large-size focal plane coupling reflex mirror integrated structure of the space camera and the coupling assembly method of the large-size focal plane coupling reflex mirror integrated structure, the main body structure of the camera can be reduced and simplified while high-resolution and large-width imaging of the space camera is met and multiple imaging channel modes are provided; the optimization of the camera load design layout is facilitated, and the installation and adjustment difficulty is reduced to a certain extent.

Description

Technical Field

[0001] The present invention relates to the technical field of the development of focal planes of aerospace optical remote sensing cameras, and particularly relates to a large-size focal plane coupling folding mirror integrated structure of a space camera and a coupling assembly method thereof. Background Art

[0002] With the rapid development of aerospace remote sensing technology, modern space optical remote sensing imaging not only has the capabilities of high resolution and large swath imaging, but also requires that the space camera payload can perform all-weather imaging of the earth and complete data transmission capabilities. This requires that multiple imaging channel modes need to be coupled and designed and assembled inside the space camera payload, generally including visible light imaging, multispectral imaging, infrared imaging (near infrared, short wave, medium wave, long wave), ultraviolet imaging mode, etc. For a space remote sensing camera payload with high resolution and large swath imaging capabilities, the designed focal length is relatively large. Limited by the launch envelope, the internal structure of the space camera payload is complex, the number of lens groups is large, and each imaging channel intersects with each other. Generally, folding mirrors are used to plan and arrange the positions of each imaging channel single machine. On the premise of not affecting the optical imaging quality, a reasonable planar folding mirror can be designed in the optical system to achieve the goal of reducing the camera envelope. Generally, the folding mirror is designed to be assembled on the main frame of the camera. For a camera with a large aperture, high resolution and multi-channel imaging mode in space, multiple groups of folding mirrors need to be arranged on the main frame of the camera to meet the overall structural design of the camera. This design scheme will make the main structure of the camera complex and increase the assembly and adjustment difficulty. Summary of the Invention

[0003] The present invention aims to solve the technical problems of the complex main structure and large assembly and adjustment difficulty of a camera with a large aperture, high resolution and multi-channel imaging mode in the prior art, and provides a large-size focal plane coupling folding mirror integrated structure of a space camera and a coupling assembly method thereof.

[0004] To solve the above technical problems, the technical solution of the present invention is specifically as follows:

[0005] A large-size focal plane coupling folding mirror integrated structure of a space camera includes: a focal plane assembly, a folding mirror assembly, and a trimming gasket; the folding mirror assembly is arranged at the light inlet position above the focal plane assembly; a trimming gasket is arranged at the connection between the focal plane assembly and the folding mirror assembly, and this trimming gasket is used to ensure the assembly accuracy between the focal plane assembly and the folding mirror assembly through lapping.

[0006] The focal plane assembly adopts an optical stitching scheme. The continuous field of view is cut into staggered fields of view by the focal plane mirror. At the same time, the staggered fields of view are divided into two mutually orthogonal directions. Two columns of detector assemblies are arranged on two mutually perpendicular outer side surfaces of the focal plane substrate. The focal plane mirror forms a 45° angle with the two columns of detector assemblies respectively. The photosensitive surfaces of the two columns of detector assemblies form a conjugate plane. Through the action of the focal plane mirror, the incident light has an equal optical path to the photosensitive surfaces of the two columns of detector assemblies. The focal plane processing circuits are respectively arranged on the back of the detector assemblies to form a complete focal plane array assembly;

[0007] The folding mirror assembly includes, from top to bottom in sequence: a folding mirror backplane, a folding mirror flexible support, and a folding mirror body; the folding mirror flexible support is installed inside the folding mirror body to ensure the surface accuracy of the folding mirror under the gravity field and temperature field; the whole composed of the folding mirror flexible support and the folding mirror body is connected to the folding mirror backplane;

[0008] The incident light entering from the light inlet is refracted by the folding mirror body, and the refracted light directly hits the focal plane photosensitive position, so as to realize the direct coupling and assembly of the folding mirror assembly and the focal plane assembly.

[0009] In the above technical solution, the folding mirror assembly and the focal plane assembly are connected by screws.

[0010] In the above technical solution, the whole composed of the folding mirror flexible support and the folding mirror body is connected to the folding mirror backplane by screws.

[0011] In the above technical solution, the folding mirror flexible support is installed inside the folding mirror body in a glued manner.

[0012] A coupling and assembly method for the integrated structure of a large-size focal plane coupling folding mirror of the above space camera includes the following steps:

[0013] The focal plane reference prism is arranged on the focal plane substrate, and at the same time, ensure that all surfaces of the focal plane reference prism can be observed; align the first theodolite with the -Y axis direction of the focal plane reference prism, and align the second theodolite with the normal direction of the folding mirror body mirror surface;

[0014] After the first theodolite and the second theodolite are aligned and leveled, clear the horizontal direction value and record the pitch direction angle value respectively;

[0015] After the first theodolite and the second theodolite aim at each other, record the horizontal direction angle value, and calculate the angle error value in the X-axis direction and the angle error value in the Z-axis direction between the folding mirror assembly and the focal plane reference prism;

[0016] Grind and repair the shim according to the angle error value in the X-axis direction, and adjust the attitude of the folding mirror assembly around the Z-axis according to the angle error value in the Z-axis direction to complete the assembly of the integrated structure of the focal plane coupling folding mirror;

[0017] In the above steps, the Y-axis direction is the reverse horizontal direction of the light input port transmission direction, the X-axis direction is the horizontal direction perpendicular to the Y-axis direction, and the Z-axis direction is the vertical direction perpendicular to the Y-axis direction.

[0018] In the above technical solution, the focal plane reference prism is arranged at the position directly below the focal plane light input port on the focal plane substrate.

[0019] The present invention has the following beneficial effects:

[0020] The integrated structure of the large-size focal plane coupling folding mirror of the space camera of the present invention and its coupling and assembly method can reduce and simplify the main structure of the camera while meeting the requirements of high-resolution and large field-of-view imaging of the space camera and having multiple imaging channel modes, which is beneficial to optimizing the design layout of the camera payload and reducing the alignment difficulty to a certain extent.

[0021] The integrated structure of the large-size focal plane coupling folding mirror of the space camera of the present invention and its coupling and assembly method are applied in engineering projects. The design and assembly of the integrated structure of the focal plane coupling folding mirror are completed, integrated with the optical lens and the outfield imaging test is completed. Clear outfield pictures are obtained from the test, further proving that this solution is reasonable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0023] Figure 1 It is a schematic cross-sectional view of the integrated structure of the large-size focal plane coupling folding mirror of the space camera of the present invention.

[0024] Figure 2 It is a schematic structural view of the integrated structure of the large-size focal plane coupling folding mirror of the space camera of the present invention.

[0025] Figure 3 It is a schematic diagram for calibrating the angular accuracy of the focal plane folding mirror.

[0026] Figure 4 It is a schematic diagram of the principle for calibrating the angular error w1 of the focal plane folding mirror around the X-axis.

[0027] Figure 5 It is a schematic diagram of the principle for calibrating the angular error w3 of the focal plane folding mirror around the Z-axis.

[0028] The reference signs in the drawings are represented as:

[0029] 1 - focal plane assembly; 2 - folding mirror assembly;

[0030] 3 - trimming gasket; 4 - focal plane substrate; 5 - focal plane mirror; 6 - detector assembly; 7 - focal plane processing circuit;

[0031] 8 - Fold - turning mirror backplane; 9 - Flexible support of fold - turning mirror; 10 - Fold - turning mirror body;

[0032] 11 - Incident light; 12 - Light after fold - turning;

[0033] 13 - Focal plane reference prism; 14 - First theodolite; 15 - Second theodolite. Specific implementation mode

[0034] The present invention will be described in detail below with reference to the accompanying drawings.

[0035] As Figure 1 and 2 shown, the integrated structure of the large - size focal plane coupling fold - turning mirror of the space camera of the present invention includes: focal plane assembly 1, fold - turning mirror assembly 2, and trimming gasket 3; the focal plane assembly 1 includes: focal plane substrate 4, focal plane mirror 5, detector assembly 6, and focal plane processing circuit 7; the fold - turning mirror assembly 2 includes: fold - turning mirror backplane 8, flexible support 9 of fold - turning mirror, and fold - turning mirror body 10. To more detailedly explain the details of the present invention, Figure 1 the incident light 11 and the light 12 after fold - turning are marked in the figure; as Figure 3 shown, the calibration and assembly of the fold - turning mirror and the focal plane assembly 1 require the use of the focal plane reference prism 13, the first theodolite 14, and the second theodolite 15.

[0036] Specifically, the integrated structure of the large - size focal plane coupling fold - turning mirror of the space camera of the present invention is composed of the focal plane assembly 1, the fold - turning mirror assembly 2, and the trimming gasket 3.

[0037] The focal plane assembly 1 adopts an optical splicing scheme. The continuous field of view is cut into staggered fields of view through the focal plane mirror 5, and at the same time, the staggered fields of view are divided into two mutually orthogonal directions. The detector assemblies 6 are respectively arranged on the precision reference focal plane substrate 4, and the focal plane processing circuit 7 is arranged on the back of the detector assembly 6, thereby forming a complete focal plane array assembly;

[0038] In the fold - turning mirror assembly 2, the flexible support 9 of the fold - turning mirror is installed inside the fold - turning mirror body 10 in a glued manner to ensure the surface accuracy of the fold - turning mirror under the gravity field and temperature field. At the same time, the whole composed of the flexible support 9 of the fold - turning mirror and the fold - turning mirror body 10 is connected to the fold - turning mirror backplane 8 by screws to form a complete fold - turning mirror assembly 2; the fold - turning mirror assembly 2 is arranged at the light - incident port position of the focal plane assembly 1 and is connected by screws, and the trimming gasket 3 is arranged at the connection position. Subsequently, the trimming gasket 3 is trimmed to ensure the assembly accuracy between the focal plane assembly 1 and the fold - turning mirror assembly 2.

[0039] In the integrated structure of the large - size focal plane coupling fold - turning mirror of the space camera of the present invention, as Figure 1As shown, the incident light 11 of the optical system passes through the folding mirror assembly 2 and directly projects the folded light 12 onto the photosensitive position of the focal plane, realizing the direct coupling and assembly of the folding mirror assembly 2 and the focal plane assembly 1, effectively simplifying the structure of the camera body.

[0040] For the integrated structure of the large-size focal plane coupling folding mirror of the space camera of the present invention, to ensure that all pixels within the photosensitive surface of the focal plane are accurately positioned within the designed field of view of the optical system, strict angular and positional accuracies are required between the folding mirror assembly 2 and the focal plane assembly 1 to ensure the smooth progress of the process of focusing the focal plane assembly 1 and the optical lens. As Figure 3 shown, the X direction is the width direction, and the effective length of the folding mirror assembly 2 covers the optical system with a margin; errors in the Y and Z directions will cause the field of view of the optical system to shift, but can be corrected by grinding the shims of the focal plane assembly 1 during the subsequent focusing and alignment process; the error w1 around the X axis and the error w3 around the Z axis will cause the focal plane to deviate from the field of view of the optical system, resulting in inconsistent imaging transfer functions of the detectors in each slice of the full field of view. The error w2 around the Y axis can be decomposed into w1 and w3, so the error w2 around the Y axis is jointly ensured by w1 and w3. The angular errors in the three directions must be accurately adjusted and positioned during the coupling stage of the folding mirror assembly 2 and the focal plane assembly 1.

[0041] When the folding mirror assembly 2 and the focal plane assembly 1 are coupled and assembled, the first theodolite 14 and the second theodolite 15 are used to complete the angular accuracy calibration. Specifically, the coupling and assembly method of the integrated structure of the large-size focal plane coupling folding mirror of the space camera of the present invention includes the following steps:

[0042] The focal plane reference prism 13 should be arranged on the precision reference focal plane substrate 4, and at the same time, ensure that all surfaces of the focal plane reference prism 13 can be observed. In the embodiment of the present invention, the focal plane reference prism 13 is arranged on the focal plane substrate 4 and is located directly below the light entrance of the focal plane. The first theodolite 14 is aligned with the -Y axis direction of the focal plane reference prism 13, and the second theodolite 15 is aligned with the normal direction of the mirror surface of the folding mirror body 10;

[0043] After the first theodolite 14 and the second theodolite 15 are aligned and leveled, the horizontal direction values are cleared, and the angular values in the pitch direction are recorded respectively;

[0044] After the first theodolite 14 and the second theodolite 15 are aimed at each other, the horizontal direction angular values are recorded, and the angular error values in the w1 and w3 directions between the folding mirror assembly 2 and the focal plane reference prism 13 can be calculated;

[0045] After obtaining the angular error values, the angular error value in the w1 direction is corrected by grinding the shim 3 between the folding mirror assembly 2 and the focal plane assembly 1, and the angular error value in the w3 direction is corrected by adjusting the attitude of the folding mirror assembly 2 around the Z axis to ensure the angular position relationship between the folding mirror assembly 2 and the focal plane assembly 1, and complete the assembly of the integrated structure of the focal plane coupling folding mirror. The specific calibration implementation plan is as Figure 3 shown.

[0046] Figure 4 This is the schematic diagram for calibrating the angular error w1 of the focal plane folding mirror about the X-axis. After the first theodolite 14 levels in the -Y direction of the focal plane reference prism 13 and records the pitch value and calculates α1, and the second theodolite 15 levels in the normal direction of the mirror surface of the folding mirror body 10 and records the pitch value and calculates α2, the measured value of the angle about the X-axis between the folding mirror assembly 2 and the focal plane reference prism 13 is:

[0047] θ 实测 = 90° - α1 - α2

[0048] The angular error w1 of the folding mirror assembly 2 and the focal plane reference prism 13 about the X-axis is:

[0049] w1 = θ 实测 -θ 理论

[0050] Figure 5 This is the schematic diagram for calibrating the angular error w3 of the focal plane folding mirror about the Z-axis. The first theodolite 14 levels in the -Y direction of the focal plane reference prism 13 and is horizontally zeroed, and the second theodolite 15 levels in the normal direction of the mirror surface of the folding mirror body 10 and is horizontally zeroed. The first theodolite 14 and the second theodolite 15 are aimed at each other, and the horizontal direction value β1 of the first theodolite 14 is recorded, and the horizontal direction value β2 of the second theodolite 15 is recorded. Theoretically, the mirror surface of the folding mirror body 10 and the focal plane reference prism 13 are parallel to each other in the angular direction about the Z-axis. The measured value of the angular error w3 of the folding mirror assembly 2 and the focal plane reference prism 13 about the Z-axis is:

[0051] w3 = 180° - β1 - β2

[0052] According to the angular error values of w1 and w3, adjust the positional relationship between the folding mirror assembly 2 and the focal plane assembly 1, and the assembly of the integrated structure of the focal plane coupling folding mirror is completed.

[0053] In the above steps, the focal plane reference prism 13 is arranged directly below the light inlet. The Y-axis direction is the reverse horizontal direction of the light transmission direction of the light inlet, the X-axis direction is the horizontal direction perpendicular to the Y-axis direction, and the Z-axis direction is the vertical direction perpendicular to the Y-axis direction.

[0054] The integrated structure of the large-size focal plane coupling folding mirror of the space camera of the present invention can reduce and simplify the main structure of the camera while meeting the requirements of high-resolution and large field-of-view imaging of the space camera and having multiple imaging channel modes, which is beneficial to optimizing the design layout of the camera payload and reducing the alignment difficulty to a certain extent.

[0055] The integrated structure of the large-sized focal plane coupling folding mirror of the space camera of the present invention has been applied in engineering projects, completing the design and assembly of the integrated structure of the focal plane coupling folding mirror, integrating with the optical lens and completing the field imaging test. Clear field pictures are obtained from the test, further proving that this solution is reasonable and reliable.

[0056] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A large-size focal plane coupled folding mirror integrated structure for a space camera, characterized in that: include: A focal plane assembly (1), a folding mirror assembly (2) and a trimming gasket (3); the folding mirror assembly (2) is arranged at a light entrance position on the upper part of the focal plane assembly (1); a trimming gasket (3) is arranged at the connection between the focal plane assembly (1) and the folding mirror assembly (2), and the trimming gasket (3) is used to ensure the assembly accuracy between the focal plane assembly (1) and the folding mirror assembly (2) through grinding; The focal plane assembly (1) adopts an optical splicing solution, and a continuous field of view is cut into staggered fields of view by a focal plane reflector (5), and the staggered fields of view are divided into two mutually orthogonal directions. Two rows of detector assemblies (6) are respectively arranged on two mutually perpendicular outer surfaces of the focal plane substrate (4), and the focal plane reflector (5) and the two rows of detector assemblies (6) are respectively at an angle of 45 degrees, and the photosensitive surfaces of the two rows of detector assemblies (6) form a conjugate surface. Through the action of the focal plane reflector (5), the incident light to the photosensitive surfaces of the two rows of detector assemblies (6) is equal in optical path, and the focal plane processing circuits (7) are respectively arranged on the back of the detector assemblies (6), so as to form a complete focal plane array assembly; The folding mirror assembly (2) comprises, arranged in order from top to bottom: a folding mirror back plate (8), a folding mirror flexible support (9) and a folding mirror body (10); the folding mirror flexible support (9) is installed inside the folding mirror body (10) to ensure the surface accuracy of the folding mirror under gravity field and temperature field; the folding mirror flexible support (9) and the folding mirror body (10) are connected to the folding mirror back plate (8); The incident light (11) entering from the light inlet is deflected by the deflecting mirror body (10), and the deflected light (12) directly hits the focal plane photosensing position, thereby realizing direct coupling assembly of the deflecting mirror assembly (2) and the focal plane assembly (1).

2. The large-size focal plane coupled folding mirror integrated structure of a space camera according to claim 1, characterized in that: The folding mirror assembly (2) and the focal plane assembly (1) are connected by screws.

3. The large-size focal plane coupling folding mirror integrated structure of a space camera according to claim 1, characterized in that: The whole composed of the folding mirror flexible support (9) and the folding mirror body (10) is connected to the folding mirror back plate (8) through screws.

4. The large-size focal plane coupling folding mirror integrated structure of a space camera according to claim 1, characterized in that: The folding mirror flexible support (9) is installed inside the folding mirror body (10) in an adhesive manner.

5. A coupling assembly method for a large-size focal plane coupling and folding mirror integrated structure of a space camera as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: The focal plane reference prism (13) is arranged on the focal plane substrate (4), and it is ensured that all surfaces of the focal plane reference prism (13) can be observed; the first theodolite (14) is aligned with the -Y axis direction of the focal plane reference prism (13), and the second theodolite (15) is aligned with the normal direction of the mirror surface of the folding mirror body (10); After the first theodolite (14) and the second theodolite (15) are aligned and leveled, the horizontal direction value is cleared and the pitch direction angle values ​​are recorded respectively; The first theodolite (14) and the second theodolite (15) are pointed at each other and record the horizontal angle value, and calculate the angle error value around the X-axis direction and the angle error value around the Z-axis direction between the folding mirror assembly (2) and the focal plane reference prism (13); According to the angle error value around the X-axis direction, the gasket (3) is repaired and cut, and the angle error value around the Z-axis direction is adjusted to adjust the posture of the folding mirror assembly (2) around the Z-axis, so as to complete the assembly of the integrated structure of the focal plane coupling folding mirror; In the above steps, the Y-axis direction is the horizontal direction opposite to the transmission direction of the light entrance, the X-axis direction is the horizontal direction perpendicular to the Y-axis direction, and the Z-axis direction is the vertical direction perpendicular to the Y-axis direction.

6. The coupling assembly method of the integrated structure of the large-size focal plane coupling folding mirror of a space camera according to claim 5, characterized in that: The focal plane reference prism (13) is arranged on the focal plane substrate (4) at a position directly below the focal plane light entrance.

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