Light and small space camera optical-mechanical system

Abstract

The invention discloses a light and small space camera optical-mechanical system, and the system comprises a main bearing assembly which is provided with bearing regions at the upper and lower parts and a supporting structure at the middle part; the primary mirror assembly and the third mirror assembly are respectively arranged at the lower part of the primary force bearing assembly through a primary mirror gasket and a third mirror gasket; the secondary mirror assembly and the fourth mirror assembly are respectively arranged at the upper part of the main bearing assembly through a secondary mirror gasket and a fourth mirror gasket; and the imaging focal plane assembly is close to the three-mirror assembly and is connected to the lower part of the main bearing assembly through an imaging focal plane gasket. The free-form surface off-axis four-mirror type optical system layout is adopted, more design freedom degrees can be released in cooperation with a truss type main force bearing configuration, the size and weight of the camera are effectively reduced, and non-blocking, large-view-field and high-quality imaging is achieved. The optical-mechanical system has the technical advantages of being compact in structure, large in width, high in image quality and the like, and the industrial application requirement of a high-resolution super-large-width space camera can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of space remote sensing cameras, and in particular to a light and small space camera optical-mechanical system. Background Art

[0002] Space remote sensing camera technology is widely used in scientific research observation, commercial remote sensing, military reconnaissance, deep space exploration and other fields. With the continuous advancement of technology, the requirements for space cameras in terms of resolution, stability, and lightweight are gradually increasing. Optical-mechanical system design is a key technology in the field of space remote sensing technology. As the requirements for imaging quality and environmental adaptability gradually increase, the research on optical-mechanical systems is developing in the direction of high precision, lightweight, high stability, and high environmental adaptability. It is urgently needed to carry out new explorations in new configurations, new materials, and new processes to meet the growing demand for space remote sensing imaging. Space cameras are generally divided into two optical system design forms: coaxial and off-axis. Compared with traditional coaxial optical systems, off-axis optical systems have the advantages of a wider field of view, a more compact configuration design, excellent aberration correction capabilities, no obstructions, and a high signal-to-noise ratio.

[0003] However, the design of off-axis optical systems is more difficult. Not only does it require extremely high positional accuracy of the reflector assembly, but it also needs to reduce the weight of the optical-mechanical structure while maintaining the static stiffness, dynamic stiffness and structural strength of the structure. At the same time, it is necessary to take into account factors such as thermal expansion and thermal stress to improve its environmental adaptability, thereby achieving a high-stability and high-environmental-adaptability optical-mechanical system design. The current optical-mechanical systems of space cameras generally have large structural weights, small widths and poor stability.

[0004] Based on the above technical problems, technicians in this field urgently need to develop a lightweight space camera optical-mechanical system with a compact structure that can better exert the imaging performance of the camera, increase the width and reduce the volume. Summary of the invention

[0005] The purpose of the present invention is to provide a light and small space camera optical-mechanical system with a compact structure, which can better exert the imaging performance of the camera, increase the width and reduce the volume.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A light and small space camera optical-mechanical system of the present invention comprises:

[0008] The main load-bearing component is a frame structure with load-bearing areas at the top and bottom and a supporting structure in the middle; and

[0009] The primary mirror assembly and the triple mirror assembly are respectively mounted on the lower part of the main load-bearing assembly through the primary mirror gasket and the triple mirror gasket;

[0010] The secondary mirror assembly and the four-mirror assembly are respectively mounted on the upper part of the main load-bearing assembly through the secondary mirror gasket and the four-mirror gasket;

[0011] The optomechanical system also includes:

[0012] The imaging focal plane assembly is located close to the three-mirror assembly and is connected to the lower part of the main load-bearing assembly through an imaging focal plane gasket.

[0013] Furthermore, the main mirror assembly is a free-form surface reflector, comprising a main mirror body, and three supporting holes are provided on the back of the main mirror body; and

[0014] A primary mirror back plate, wherein the primary mirror body is connected to the primary mirror back plate via three primary mirror flexible supports;

[0015] The main mirror back plate is provided with three main mirror mechanical interfaces, and the main mirror assembly is mounted on the main load-bearing assembly via the main mirror mechanical interfaces.

[0016] Furthermore, the secondary mirror assembly is a secondary aspherical reflector, comprising a secondary mirror body, and a support hole is provided at the center of the back of the secondary mirror body; and

[0017] A secondary mirror back plate, wherein the secondary mirror body is connected to the secondary mirror back plate via a secondary mirror flexible support;

[0018] Furthermore, three secondary mirror mechanical interfaces are arranged on the secondary mirror back plate, and the secondary mirror assembly is installed on the main load-bearing assembly through the secondary mirror mechanical interfaces.

[0019] Furthermore, the three-mirror assembly is a free-form surface reflector, comprising a three-mirror body, and three supporting holes are provided on the back of the three-mirror body; and

[0020] A three-mirror back plate is connected to the three-mirror body through three three-mirror flexible supports, three three-mirror mechanical interfaces are arranged on the three-mirror back plate, and the three-mirror assembly is installed on the main load-bearing assembly through the three-mirror mechanical interfaces.

[0021] Furthermore, the four-mirror assembly is a high-order aspheric reflector, comprising a four-mirror body, and three supporting holes are provided on the back of the four-mirror body; and

[0022] A four-mirror back plate is connected to the four-mirror body through three four-mirror flexible supports, three four-mirror mechanical interfaces are arranged on the four-mirror back plate, and the four-mirror assembly is installed on the main load-bearing assembly through the four-mirror mechanical interfaces.

[0023] Further, the main load-bearing assembly includes a front frame, which is a stepped flat plate structure and is provided with a secondary mirror assembly mounting surface and a quad mirror assembly mounting surface;

[0024] The rear frame is a flat frame structure and is provided with a primary mirror assembly mounting surface, a three-mirror assembly mounting surface and an imaging focal plane assembly mounting surface;

[0025] A plurality of truss rods are connected between the front frame and the rear frame through rod joints.

[0026] Preferably, the truss rods are cylindrical hollow thin-walled straight rods, and the number of the truss rods is eight, which are combined to support and connect the front frame and the rear frame to form a truss-type main support structure.

[0027] Furthermore, the imaging focal plane assembly includes a focal plane box, and the incident light is refracted through the optical path of four reflectors and then imaged on the sensor in the focal plane box; and

[0028] A focusing mechanism capable of driving the focal plane box to move to obtain an image plane position;

[0029] An imaging focal plane assembly mechanical interface is provided on the side of the focal plane box, and the imaging focal plane assembly is installed on the main load-bearing assembly through the imaging focal plane assembly mechanical interface.

[0030] In the above technical solution, the light and small space camera optical-mechanical system provided by the present invention has the following beneficial effects:

[0031] The light and small space camera optical system of the present invention adopts a free-form off-axis four-mirror optical system layout, and cooperates with a truss-type main load-bearing configuration, which can release more design freedom, effectively reduce the size and weight of the camera, and achieve unobstructed, large field of view, and high-quality imaging. The optical system of the present invention has the technical advantages of compact structure, large width, high image quality, etc., and can meet the industrial application requirements of high-resolution and ultra-wide-width space cameras. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0033] Figure 1 A schematic diagram of the overall structure of a light and small space camera optical-mechanical system provided by an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of the overall structure of a light and small space camera optical-mechanical system provided by an embodiment of the present invention;

[0035] Figure 3 A schematic structural diagram of a primary mirror assembly of an optical-mechanical system of a lightweight space camera provided by an embodiment of the present invention;

[0036] Figure 4 A schematic structural diagram of a secondary mirror assembly of a light and small space camera optical-mechanical system provided by an embodiment of the present invention;

[0037] Figure 5 A schematic diagram of the structure of a three-mirror assembly of a light and small space camera optical-mechanical system provided by an embodiment of the present invention;

[0038] Figure 6 A schematic diagram of the structure of a four-mirror assembly of a light and small space camera optical-mechanical system provided by an embodiment of the present invention;

[0039] Figure 7 A schematic diagram of the structure of the main load-bearing components of an optical-mechanical system of a light and small space camera provided by an embodiment of the present invention;

[0040] Figure 8 A schematic diagram of the reverse structure of the main load-bearing component of the optical-mechanical system of a light and small space camera provided by an embodiment of the present invention;

[0041] Fig. 9 A schematic diagram of the structure of an imaging focal plane component of an optical-mechanical system of a lightweight and small space camera provided in an embodiment of the present invention.

[0042] Description of reference numerals:

[0043] 1, primary mirror assembly; 2, secondary mirror assembly; 3, three-mirror assembly; 4, four-mirror assembly; 5, main bearing assembly; 6, imaging focal plane assembly; 7, primary mirror gasket; 8, secondary mirror gasket; 9, three-mirror gasket; 10, four-mirror gasket; 11, imaging focal plane gasket;

[0044] 101, main mirror body; 102, main mirror flexible support; 103, main mirror back plate; 104, main mirror assembly mechanical interface;

[0045] 201, secondary mirror body; 202, secondary mirror flexible support; 203, secondary mirror back plate; 204, secondary mirror assembly mechanical interface;

[0046] 301, three-mirror body; 302, three-mirror flexible support; 303, three-mirror back plate; 304, three-mirror assembly mechanical interface;

[0047] 401, four-mirror body; 402, four-mirror flexible support; 403, four-mirror back plate; 404, four-mirror assembly mechanical interface;

[0048] 501, front frame; 502, truss rod; 503, rod joint; 504, rear frame; 505, primary mirror assembly mounting surface; 506, secondary mirror assembly mounting surface; 507, three-mirror assembly mounting surface; 508, four-mirror assembly mounting surface; 509, imaging focal plane assembly mounting surface;

[0049] 601, focal plane box; 602, focusing mechanism; 603, imaging focal plane assembly mechanical interface. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0051] This embodiment is used for a free-form surface off-axis quad-mirror space camera with an ultra-wide width of 150km and an image resolution better than 0.5m. The overall envelope size of the camera is within 900mm*860mm*780mm, and the camera optical and mechanical system has a compact structure and a high degree of lightweight.

[0052] See also Figures 1 to 9 As shown;

[0053] A light and small space camera optical-mechanical system of the present invention comprises:

[0054] The main load-bearing component 5 is a frame-type structure with load-bearing areas at the top and bottom and a support structure in the middle; and

[0055] The main mirror assembly 1 and the three-mirror assembly 3 are respectively mounted on the lower part of the main load-bearing assembly 5 through the main mirror gasket 7 and the three-mirror gasket 9;

[0056] The secondary mirror assembly 2 and the quad mirror assembly 4 are mounted on the upper part of the main load bearing assembly 5 through the secondary mirror gasket 8 and the quad mirror gasket 10 respectively;

[0057] The optomechanical system also includes:

[0058] The imaging focal plane assembly 6 is located close to the three-mirror assembly 3 and is connected to the lower part of the main load-bearing assembly 5 through an imaging focal plane gasket 11 .

[0059] As a further introduction to this embodiment, the main mirror assembly 1 is a free-form surface reflector, comprising a main mirror body 101, and three supporting holes are provided on the back of the main mirror body 101; and

[0060] A primary mirror back plate 103, the primary mirror body 101 is connected to the primary mirror back plate 103 via three primary mirror flexible supports 102;

[0061] The main mirror back plate 103 is provided with three main mirror mechanical interfaces 104 , and the main mirror assembly 1 is installed on the main load-bearing assembly 5 via the main mirror mechanical interfaces 104 .

[0062] As a further introduction to this embodiment, the secondary mirror assembly 2 is a secondary aspherical reflector, comprising a secondary mirror body 201, wherein a support hole is provided at the center of the back of the secondary mirror body 201; and

[0063] A secondary mirror back plate 203, the secondary mirror body 201 is connected to the secondary mirror back plate 203 via a secondary mirror flexible support 202;

[0064] Furthermore, three secondary mirror mechanical interfaces 204 are provided on the secondary mirror back plate 203 , and the secondary mirror assembly 2 is installed on the main load-bearing assembly 5 via the secondary mirror mechanical interfaces 204 .

[0065] As a further introduction to this embodiment, the three-mirror assembly 3 is a free-form surface reflector, including a three-mirror body 301, and three supporting holes are provided on the back of the three-mirror body 301; and

[0066] A three-mirror back plate 303 is connected to the three-mirror body 301 via three three-mirror flexible supports 302 , and three three-mirror mechanical interfaces 304 are provided on the three-mirror back plate 303 . The three-mirror assembly 3 is installed on the main load-bearing assembly 5 via the three-mirror mechanical interfaces 304 .

[0067] As a further introduction to this embodiment, the four-mirror assembly 4 is a high-order aspheric reflector, including a four-mirror body 401, and three supporting holes are provided on the back of the four-mirror body 401; and

[0068] A four-mirror back plate 403 is connected to the four-mirror body 401 via three four-mirror flexible supports 402 , three four-mirror mechanical interfaces 404 are provided on the four-mirror back plate 403 , and the four-mirror assembly 4 is mounted on the main load-bearing assembly 5 via the four-mirror mechanical interfaces 404 .

[0069] It should be noted that, in the present invention, the primary mirror body 101, the secondary mirror body 201, the third mirror body 301 and the fourth mirror body 401 are all made of silicon carbide material, the back of the mirror body is lightweight, and the mirror surface is finally formed into a high-precision reflective surface after mechanical processing, optical processing, surface modification, and optical coating;

[0070] The primary mirror flexible support 102, the secondary mirror flexible support 202, the third mirror flexible support 302 and the fourth mirror flexible support 402 are all made of invar material that matches the linear expansion coefficient of the mirror body silicon carbide material, and are provided with flexible links, which can effectively eliminate the changes in the reflector surface caused by gravity, temperature, assembly errors, etc., provide highly stable reflector support and high-precision reflector surface accuracy, and the surface accuracy of each reflector can reach more than 1 / 60λ;

[0071] The primary mirror back plate 103, the secondary mirror back plate 203, the third mirror back plate 303 and the fourth mirror back plate 403 are all made of high volume fraction aluminum-based silicon carbide material with high specific stiffness. They are highly lightweight flat plate configurations and are formed by CNC precision milling.

[0072] As a further introduction to this embodiment, the main load-bearing assembly 5 includes a front frame 501, which is a stepped flat plate structure and is provided with a secondary mirror assembly mounting surface 506 and a quad mirror assembly mounting surface 508;

[0073] The rear frame 504 is a flat frame structure, and is provided with a main mirror assembly mounting surface 505, a three-mirror assembly mounting surface 507 and an imaging focal plane assembly mounting surface 509, and can also provide a camera external mechanical interface or other stand-alone interfaces as required;

[0074] A plurality of truss rods 502 are connected between the front frame 501 and the rear frame 504 through rod joints 503, and are connected by pin positioning and screw connection to achieve high-precision assembly and reliable connection. In the present invention, the front frame 501, the rear frame 504, and the rod joints 503 are made of high-volume aluminum-based silicon carbide material and are formed by CNC precision milling. Since they are made of the same material as the back plate of the reflector, the consistency of material properties can be better guaranteed, and a high-stability main support configuration can be achieved by perfect matching of linear expansion. The truss rods 502 are automatically wound and formed by carbon fiber materials. The designability of the carbon fiber material properties is utilized, and the stiffness and linear expansion coefficient of the truss rods 502 are adjusted by designing the winding angle of the fiber, thereby achieving precise main support structure design and thermal compensation control.

[0075] As a preferred technical solution of this embodiment, the truss rods 503 are cylindrical hollow thin-walled straight rods, and the number of the truss rods 503 is eight, which are combined to support and connect the front frame 501 and the rear frame 504 to form a truss-type main support structure.

[0076] As a further introduction to this embodiment, the imaging focal plane assembly 6 includes a focal plane box 601, and the incident light is refracted through the optical path of four reflectors and then imaged on the sensor in the focal plane box 601; and

[0077] A focusing mechanism 602, which can drive the focal plane box 601 to move to obtain an image plane position;

[0078] An imaging focal plane assembly mechanical interface 603 is disposed on the side of the focal plane box 601 , and the imaging focal plane assembly 6 is mounted on the main load-bearing assembly 5 via the imaging focal plane assembly mechanical interface 603 .

[0079] In the above technical solution, the light and small space camera optical-mechanical system provided by the present invention has the following beneficial effects:

[0080] The light and small space camera optical system of the present invention adopts a free-form off-axis four-mirror optical system layout, combined with a truss-type main load-bearing configuration, which can release more design freedom, effectively reduce the size and weight of the camera, and achieve unobstructed, large field of view, and high-quality imaging. The optical system of the present invention has the technical advantages of compact structure, large width, high image quality, etc., and can meet the industrial application needs of high-resolution and ultra-wide-width space cameras;

[0081] In the present invention, each reflector is made of silicon carbide material, the mirror body is highly lightweight and has good long-term stability; each reflector back plate, main load-bearing front and rear frames and other optical and mechanical structural parts are made of high-volume aluminum-based silicon carbide material with good material consistency; the linear expansion coefficients between the above-mentioned components are highly matched, and have good thermal conductivity, which is conducive to reducing the temperature sensitivity of the overall optical and mechanical structure. Therefore, the space camera has good thermal compensation effect, stable structure, good adaptability to space environment and long-term on-orbit stability;

[0082] Silicon carbide reflectors, high volume fraction aluminum-based silicon carbide frame plates, and carbon fiber trusses all maximize the performance advantages of advanced aerospace materials in terms of high specific stiffness, and can achieve optimal lightweight structural design, which is conducive to the mass production and commercial application of space cameras.

[0083] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A light and small space camera optical and mechanical system, characterized in that: The optomechanical system includes: The main load-bearing component (5) is a frame-type structure, and has load-bearing areas at the top and bottom, and a supporting structure in the middle; and The main mirror assembly (1) and the three-mirror assembly (3) are respectively mounted on the lower part of the main load-bearing assembly (5) via a main mirror gasket (7) and a three-mirror gasket (9); The secondary mirror assembly (2) and the quad mirror assembly (4) are respectively mounted on the upper part of the main load bearing assembly (5) via a secondary mirror gasket (8) and a quad mirror gasket (10); The optomechanical system also includes: An imaging focal plane assembly (6) is located close to the three-mirror assembly (3) and is connected to the lower part of the main load-bearing assembly (5) via an imaging focal plane gasket (11).

2. The light and small space camera optical-mechanical system according to claim 1, characterized in that: The main mirror assembly (1) is a free-form surface reflector, comprising a main mirror body (101), wherein three supporting holes are provided on the back of the main mirror body (101); and A primary mirror back plate (103), wherein the primary mirror body (101) is connected to the primary mirror back plate (103) via three primary mirror flexible supports (102); The main mirror back plate (103) is provided with three main mirror mechanical interfaces (104), and the main mirror assembly (1) is mounted on the main load-bearing assembly (5) via the main mirror mechanical interfaces (104).

3. The light and small space camera optical-mechanical system according to claim 1, characterized in that: The secondary mirror assembly (2) is a secondary aspherical reflector, comprising a secondary mirror body (201), wherein a support hole is provided at the center of the back of the secondary mirror body (201); and A secondary mirror back plate (203), wherein the secondary mirror body (201) is connected to the secondary mirror back plate (203) via a secondary mirror flexible support (202); Furthermore, three secondary mirror mechanical interfaces (204) are provided on the secondary mirror back plate (203), and the secondary mirror assembly (2) is mounted on the main load-bearing assembly (5) via the secondary mirror mechanical interfaces (204).

4. The light and small space camera optical-mechanical system according to claim 1, characterized in that: The three-mirror assembly (3) is a free-form surface reflector, comprising a three-mirror body (301), wherein three supporting holes are provided on the back of the three-mirror body (301); and A three-mirror back plate (303) is connected to the three-mirror body (301) via three three-mirror flexible supports (302), three three-mirror mechanical interfaces (304) are provided on the three-mirror back plate (303), and the three-mirror assembly (3) is mounted on the main load-bearing assembly (5) via the three-mirror mechanical interfaces (304).

5. The light and small space camera optical-mechanical system according to claim 1, characterized in that: The four-mirror assembly (4) is a high-order aspheric reflector, comprising a four-mirror body (401), wherein three supporting holes are provided on the back of the four-mirror body (401); and A four-mirror back plate (403) is connected to the four-mirror body (401) via three four-mirror flexible supports (402), three four-mirror mechanical interfaces (404) are provided on the four-mirror back plate (403), and the four-mirror assembly (4) is mounted on the main load-bearing assembly (5) via the four-mirror mechanical interfaces (404).

6. The light and small space camera optical-mechanical system according to claim 1, characterized in that: The main load-bearing component (5) comprises a front frame (501) which is a stepped flat plate structure and is provided with a secondary mirror component mounting surface (506) and a quad mirror component mounting surface (508); The rear frame (504) is a flat frame structure and is provided with a primary mirror assembly mounting surface (505), a triple mirror assembly mounting surface (507) and an imaging focal plane assembly mounting surface (509); A plurality of truss rods (502) are connected between the front frame (501) and the rear frame (504) via rod joints (503).

7. The light and small space camera optical-mechanical system according to claim 6, characterized in that: The truss rods (503) are cylindrical hollow thin-walled straight rods, and the number of the truss rods (503) is eight, which are combined to support and connect the front frame (501) and the rear frame (504) to form a truss-type main support structure.

8. The light and small space camera optical-mechanical system according to claim 1, characterized in that: The imaging focal plane assembly (6) comprises a focal plane box (601), and incident light is refracted through the optical paths of four reflectors to form an image on a sensor in the focal plane box (601); and A focusing mechanism (602) capable of driving the focal plane box (601) to move to obtain an image plane position; An imaging focal plane assembly mechanical interface (603) is provided on the side of the focal plane box (601), and the imaging focal plane assembly (6) is mounted on the main load-bearing assembly (5) via the imaging focal plane assembly mechanical interface (603).

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