An ultra-large aperture sub-aperture stitching collimation system

Abstract

The present invention relates to an ultra-large aperture sub-aperture splicing collimation system, comprising: a plane mirror assembly and a splicing adjustment mechanism, wherein the plane mirror assembly comprises a plane mirror, a support hook, an execution back plate and a support back plate, wherein the support back plate is connected to the execution back plate; the internal structure of the plane mirror is a honeycomb weight reduction form, and a hanging hole structure is provided on the back for installing the support hook; the splicing adjustment mechanism plays a role in adjusting the plane mirror assembly, and has an electric four-dimensional adjustment function. The present invention realizes the unloading support of a 2m diameter plane reflector with the mirror surface facing downward and the optical axis in a vertical state, the support structure is stable and the support error generated is small, and the optical system detection requirements are met.

Description

Technical Field

[0001] The invention relates to an ultra-large aperture sub-aperture splicing and collimation system, belonging to the technical field of optical assembly and adjustment of remote sensing cameras. Background Art

[0002] As aerospace remote sensors pursue higher resolution, the aperture of remote sensing cameras has also increased. Due to the influence of gravity deformation, large-aperture remote sensing cameras usually use a vertical optical axis to adjust the optical system. To carry out vertical adjustment, a vertical plane mirror that is not smaller than the camera aperture must be equipped to achieve self-collimation interferometric measurement of the camera.

[0003] For the detection of large-aperture optical systems, large-aperture interferometers or plane mirrors of equal aperture are usually used to achieve self-collimation of the optical path. The aperture of remote sensing cameras currently developed in China is less than 1.5m, and the use of plane mirrors of equal aperture can meet the detection needs. There is a lack of corresponding detection methods for large-aperture optical systems with a diameter of 2m or more. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and propose an ultra-large aperture sub-aperture splicing collimation system, which improves the measurement aperture while ensuring detection accuracy and overcomes the defect that a small aperture collimating plane mirror cannot detect the full aperture of the optical system.

[0005] The solution of the present invention is:

[0006] An ultra-large aperture sub-aperture splicing collimation system comprises: a plane mirror assembly and a splicing adjustment mechanism,

[0007] The plane mirror assembly includes a plane mirror, a support hook, an execution back plate and a support back plate, and the support back plate is connected to the execution back plate; the internal structure of the plane mirror is a honeycomb weight reduction form, and there is a hanging hole structure on the back for installing the support hook;

[0008] The support hook connects the plane mirror and the execution back plate, the upper end of the support hook is connected to the execution back plate, the support hook extends from the hole corresponding to the plane mirror, and the hanging spring is unfolded to realize the hoisting support of the plane mirror, and the position locking of one end of the plane mirror is realized, and the adjustment pressure ring can adjust and lock the position according to the distance between the execution back plate and the plane mirror;

[0009] The splicing adjustment mechanism plays the role of adjusting the plane mirror assembly and has the function of electric four-dimensional adjustment;

[0010] The splicing adjustment mechanism includes a main adjustment back plate, a sub-adjustment back plate, a tilt adjustment motor and a transfer plate, wherein the main adjustment back plate is installed with an X-direction guide rail, the sub-adjustment back plate is placed on the X-direction guide rail, and the one-dimensional translation adjustment of the sub-adjustment back plate in the X direction is achieved by driving the lead screw motor;

[0011] A guide rail in the Y direction is installed on the auxiliary adjustment back plate, and the adapter plate is placed on the guide rail in the Y direction. The one-dimensional translation adjustment of the adapter plate in the Y direction is realized by the lead screw motor drive;

[0012] One end of the main adjustment back plate is connected to the test installation surface through an adaptive ball joint, and the other end is installed on the test installation surface through two sets of tilt adjustment motors. By adjusting the height of the two sets of tilt adjustment motors, the two-dimensional tilt angle adjustment of the main adjustment back plate can be achieved;

[0013] The supporting back plate of the plane mirror assembly is connected to the adapter plate; by adjusting the two-dimensional direction and two-dimensional tilt angle of the plane mirror, the full-aperture imaging quality of the large-aperture remote sensing camera can be detected.

[0014] Furthermore, the plane mirror is a coated reflector, and the reflector is in use with the optical axis vertical and the mirror surface facing downward.

[0015] Furthermore, the supporting hook includes a connecting shaft, an adjusting pressure ring, a flexible pressure plate, a locking pressure cup, a connecting ring and a hanging spring plate. The lower end of the connecting shaft is connected to the hanging spring plate. The flexible pressure plate passes through the connecting shaft to press the locking pressure cup onto the flexible pressure plate. The connecting ring passes through the connecting shaft and can move up and down along the connecting shaft. By adjusting the position of the connecting ring, the distance between the plane mirror and the execution back plate is controlled. Finally, the connecting ring fits the execution back plate and is locked by the adjusting pressure ring.

[0016] Furthermore, a plurality of suspension holes are provided on the plane mirror, and the deformation of the plane mirror is controlled to be no greater than 0.03λ by selecting the positions of the suspension holes and the action of the suspension springs, where λ is the wavelength of the test light source.

[0017] Furthermore, the connection shaft above the suspension spring is recessed in the axial direction, and the suspension spring can be rotatably placed in the recess.

[0018] Furthermore, the two-dimensional tilt angle adjustment accuracy α is the adjustment accuracy of the lifting motor, D x It is the span between the system support points.

[0019] Furthermore, the tilt angle adjustment range is ±2°.

[0020] Furthermore, the lower end of the supporting hook is placed into the hanging hole of the plane mirror, the hanging spring leaves the recess, rotates open, and the locking pressure cup is adjusted downward so that the flexible pressure plate is embedded in the groove on the back of the plane mirror. The hanging spring contacts the upper end surface of the hanging hole to achieve locking of the plane mirror.

[0021] Furthermore, the plane mirror assembly realizes the unloading support of the 2m aperture plane mirror in the mirror-face-down state. With the support of the mirror support structure, the plane mirror can ensure that the RMS value of the surface shape when the optical axis is in the vertical state is better than 0.03λ, where λ is the wavelength of the test light source.

[0022] Furthermore, the splicing adjustment mechanism has four-dimensional electric adjustment capabilities, including two-dimensional tilt angle adjustment and two-dimensional translation adjustment capabilities. The splicing adjustment mechanism can meet the splicing detection requirements within a 3.2m diameter, and the splicing accuracy can reach 0.05mm.

[0023] The beneficial effects of the present invention compared with the prior art are:

[0024] (1) The present invention realizes the unloading support of a 2m diameter plane reflector with the mirror surface facing downward and the optical axis in a vertical state. The support structure is stable and the support error is small, which meets the optical system detection requirements;

[0025] (2) The splicing mechanism of the present invention reduces the overall outer envelope size of the system by integrating and distributing multiple motors; splitting the adjustment functions of different dimensions to achieve four-dimensional decoupling adjustment while effectively ensuring the stability of the system structure;

[0026] (3) The present invention applies the sub-aperture stitching mechanism, and the system realizes the function of using a small-sized plane mirror to detect a large-sized optical system. It is the first collimation system in China with the ability to detect 3m-aperture optical systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a system structure diagram of the present invention;

[0028] Figure 2 This is a structural diagram of a plane mirror assembly of the present invention;

[0029] Figure 3 The backplane structure diagram for the present invention is implemented;

[0030] Figure 4 This is a structural diagram of the plane mirror body of the present invention;

[0031] Figure 5 It is a structural diagram of the support hook of the present invention;

[0032] Figure 6 This is a diagram of the splicing adjustment mechanism of the present invention;

[0033] Figure 7 It is a schematic diagram of the adjustment range of the plane mirror of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the embodiments.

[0035] An ultra-large aperture sub-aperture stitching collimation system, such as Figure 1 As shown, it includes: a plane mirror assembly 1 and a splicing adjustment mechanism 2,

[0036] The plane mirror assembly 1 includes a plane mirror 1-1, a support hook 1-2, an execution back plate 1-3 and a support back plate 1-4, and the support back plate 1-4 is connected to the execution back plate 1-3; the plane mirror 1-1 is a coated reflector, and the reflector is used in a state where the optical axis is vertical and the mirror surface is downward, and the internal structure of the plane mirror 1-1 is a honeycomb weight reduction form, such as Figure 4 As shown, there is a hanging hole structure on the back for installing the support hooks 1-2;

[0037] like Figure 2 , 3 As shown, the support hook 1-2 connects the plane mirror 1-1 and the execution back plate 1-3, the upper end of the support hook 1-2 is connected to the execution back plate 1-3, the support hook 1-2 extends from the hole corresponding to the plane mirror 1-1, and three suspension springs are deployed to realize the lifting support of the plane mirror 1-1, and the position locking of one end of the plane mirror is realized, and the adjustment pressure ring can be adjusted and locked according to the distance between the execution back plate 1-3 and the plane mirror 1-1;

[0038] like Figure 5 As shown, the support hook 1-2 includes a connecting shaft 1-4, an adjusting pressure ring 1-5, a flexible pressure sheet 1-7, a locking pressure cup 1-6, a connecting ring 1-9 and a hanging spring sheet 1-8. The lower end of the connecting shaft is connected with a hanging spring sheet. The flexible pressure sheet penetrates into the connecting shaft, and the locking pressure cup is pressed on the flexible pressure sheet; the connecting ring penetrates into the connecting shaft and can move up and down along the connecting shaft. By adjusting the position of the connecting ring, the distance between the plane mirror 1-1 and the execution back plate 1-3 is controlled. Finally, the connecting ring fits with the execution back plate 1-3 and is locked by the adjusting pressure ring.

[0039] The connecting shaft above the suspension spring is concave in the axial direction, and the suspension spring can be rotated and placed in the concave. At this time, the lower end of the support hook 1-2 is placed in the suspension hole of the plane mirror 1-1, and the suspension spring leaves the concave, rotates and opens, and adjusts the locking pressure cup downward to make the flexible pressure piece embedded in the groove on the back of the plane mirror 1-1. The suspension spring contacts the upper end surface of the suspension hole to achieve locking of the plane mirror 1-1;

[0040] A plurality of suspension holes are provided on the plane mirror 1-1. By selecting the positions of the suspension holes and the function of the suspension springs, the deformation of the plane mirror 1-1 is controlled to be no greater than 0.03λ, where λ is the wavelength of the test light source;

[0041] The splicing adjustment mechanism 2 plays the role of adjusting the plane mirror assembly 1 and has an electric four-dimensional adjustment function;

[0042] like Figure 6As shown, the splicing adjustment mechanism 2 includes a main adjustment back plate 2-1, a sub-adjustment back plate 2-2, a tilt adjustment motor 2-3 and a transfer plate 2-4, wherein the main adjustment back plate 2-1 is installed with an X-direction guide rail, and the sub-adjustment back plate 2-2 is placed on the X-direction guide rail, and the one-dimensional translation adjustment of the sub-adjustment back plate 2-2 in the X direction is realized by driving the lead screw motor;

[0043] A guide rail in the Y direction is installed on the auxiliary adjustment back plate 2-2, and the adapter plate 2-4 is placed on the guide rail in the Y direction. The one-dimensional translation adjustment of the adapter plate 2-4 in the Y direction is realized by driving the lead screw motor;

[0044] One end of the main adjustment back plate 2-1 is connected to the test installation surface through an adaptive ball head hinge, and the other end is installed on the test installation surface through two sets of tilt adjustment motors 2-3. By adjusting the height of the two sets of tilt adjustment motors 2-3, the two-dimensional tilt angle adjustment of the main adjustment back plate 2-1 is achieved;

[0045] The support back plate 1-4 of the plane mirror assembly 1 is connected to the adapter plate 2-4; by adjusting the two-dimensional direction and two-dimensional tilt angle of the plane mirror 1-1, such as Figure 7 As shown, the full-aperture imaging quality detection of the large-aperture remote sensing camera is realized.

[0046] Tilt angle adjustment accuracy α is the adjustment accuracy of the lifting motor, D x is the span between the system support points;

[0047] The tilt angle adjustment range is plus or minus 2°.

[0048] The plane mirror assembly 1 realizes the unloading support of the 2m-diameter plane mirror in the mirror-face-down state. With the support of the mirror support structure, the plane mirror can ensure that the surface RMS value of the optical axis in the vertical state is better than 0.03λ, and the λ wavelength is preferably 632.8nm;

[0049] The splicing adjustment mechanism 2 has four-dimensional electric adjustment capability, including two-dimensional tilt angle adjustment and two-dimensional translation adjustment capability. The splicing adjustment mechanism can meet the splicing detection requirements within a 3.2m diameter, and the splicing accuracy can reach 0.05mm.

[0050] The electronic control system of the adjustment mechanism is composed of 5 servo motors and their related sensors. The two horizontal directions of the adjustment mechanism are controlled by two groups of 3 servo motors. The upper translation adjustment link is controlled by two motors at the same time. The angle pitch is lifted and lowered by stepper motors installed at two adjustable supports to achieve the angle adjustment of the adjustment mechanism around the axis.

[0051] The combination of the above adjustment mechanism and the plane mirror is a solution to meet the image quality detection of the 3m aperture remote sensing camera optical system under the condition of only having a 2m aperture plane mirror. Therefore, the plane mirror needs to cover the entire incident aperture of the camera while maintaining collimation with the camera's visual axis.

[0052] In order to accurately measure the image quality of remote sensing cameras with a diameter of 3m, a new type of vertical sub-aperture stitching and collimation system is proposed to meet the requirements of image quality detection of ultra-large aperture remote sensing cameras. That is, 2m aperture plane mirrors are used to stitch to achieve 3m aperture image quality measurement. The system mainly breaks through two technical difficulties: ① It solves the problem of support deformation of the 2m aperture plane mirror with the mirror surface downward in the vertical state of the optical axis; ② It solves the problem of sub-aperture stitching adjustment accuracy and stability of the 2m aperture plane mirror.

[0053] The design results show that the detection system has the following characteristics: ① strong versatility; ② high measurement accuracy; ③ large measurement range, etc. It can better solve the problem of insufficient aperture of large-aperture reflectors and large surface shape changes of the support in the vertical state of the optical axis.

[0054] As the aperture and volume of remote sensor lenses become larger and larger, the gravity deformation of the camera has a more serious impact on the image quality of the system. The traditional optical axis horizontal assembly process route will no longer be suitable for the subsequent large-aperture model development due to the large cantilever of the camera secondary mirror, which will cause structural deformation and position changes. The sub-aperture splicing test system proposed in the results has the ability to detect when the optical axis is vertical, is not limited by the aperture size of the plane mirror, and the splicing measurement accuracy meets the image quality test requirements. It can be widely used in the subsequent system image quality detection of various large-aperture and ultra-large-aperture cameras.

[0055] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An ultra-large aperture sub-aperture splicing collimation system, characterized in that: include: Plane mirror assembly (1) and splicing adjustment mechanism (2), The plane mirror assembly (1) comprises a plane mirror (1-1), a support hook (1-2), an execution back plate (1-3) and a connecting shaft (1-4) included in the support hook (1-2), wherein the connecting shaft (1-4) is connected to the execution back plate (1-3); the internal structure of the plane mirror (1-1) is a honeycomb weight-reducing form, and a hanging hole structure is provided on the back for installing the support hook (1-2); The support hook (1-2) is connected to the plane mirror (1-1) and the execution back plate (1-3), the upper end of the support hook (1-2) is connected to the execution back plate (1-3), the support hook (1-2) extends from the hole corresponding to the plane mirror (1-1), and the hanging spring sheet is unfolded to realize the lifting support of the plane mirror (1-1), and the position locking of one end of the plane mirror is realized, and the adjustment pressure ring can adjust the position and lock it according to the distance between the execution back plate (1-3) and the plane mirror (1-1); The splicing adjustment mechanism (2) plays a role in adjusting the plane mirror assembly (1) and has an electric four-dimensional adjustment function; The splicing adjustment mechanism (2) comprises a main adjustment back plate (2-1), a secondary adjustment back plate (2-2), a tilt adjustment motor (2-3) and a transfer plate (2-4), wherein a guide rail in the X direction is installed on the main adjustment back plate (2-1), the secondary adjustment back plate (2-2) is placed on the guide rail in the X direction, and the secondary adjustment back plate (2-2) is driven by a lead screw motor to achieve one-dimensional translation adjustment in the X direction; A guide rail in the Y direction is installed on the auxiliary adjustment back plate (2-2), and the adapter plate (2-4) is placed on the guide rail in the Y direction, and the one-dimensional translation adjustment of the adapter plate (2-4) in the Y direction is achieved through the drive of a lead screw motor; One end of the main adjustment back plate (2-1) is connected to the test installation surface via an adaptive ball head hinge, and the other end is installed on the test installation surface via two sets of tilt adjustment motors (2-3). By adjusting the heights of the two sets of tilt adjustment motors (2-3), the two-dimensional tilt angle adjustment of the main adjustment back plate (2-1) is achieved; The connecting shaft (1-4) of the plane mirror assembly (1) is connected to the adapter plate (2-4); by adjusting the two-dimensional direction and the two-dimensional tilt angle of the plane mirror (1-1), the full-aperture imaging quality of the large-aperture remote sensing camera can be detected; The supporting hook (1-2) comprises a connecting shaft (1-4), an adjusting pressure ring (1-5), a flexible pressure sheet (1-7), a locking pressure cup (1-6), a connecting ring (1-9) and a hanging spring sheet (1-8). The lower end of the connecting shaft is connected with the hanging spring sheet. The flexible pressure sheet penetrates into the connecting shaft and presses the locking pressure cup onto the flexible pressure sheet. The connecting ring penetrates into the connecting shaft and can move up and down along the connecting shaft. By adjusting the position of the connecting ring, the distance between the plane mirror (1-1) and the execution back plate (1-3) is controlled. Finally, the connecting ring fits with the execution back plate (1-3) and is locked by the adjusting pressure ring. The connecting shaft above the suspension spring is recessed in the axial direction, and the suspension spring can be rotated and placed in the recess; The lower end of the support hook (1-2) is placed in the hanging hole of the plane mirror (1-1), the hanging spring piece leaves the recess, rotates and opens, and the locking pressure cup is adjusted downward so that the flexible pressure piece is embedded in the groove on the back of the plane mirror (1-1), and the hanging spring piece contacts the upper end surface of the hanging hole, thereby locking the plane mirror (1-1).

2. The ultra-large aperture sub-aperture stitching collimation system according to claim 1, characterized in that: The plane mirror (1-1) is a coated reflector, and the reflector is in a use state with the optical axis vertical and the mirror surface downward.

3. The ultra-large aperture sub-aperture stitching collimation system according to claim 1, characterized in that: A plurality of suspension holes are arranged on the plane mirror (1-1), and the deformation of the plane mirror (1-1) is controlled to be no greater than 0.03λ by selecting the positions of the suspension holes and the action of the suspension spring pieces, where λ is the wavelength of the test light source.

4. The ultra-large aperture sub-aperture stitching collimation system according to claim 1, characterized in that: 2D tilt angle adjustment accuracy α is the adjustment accuracy of the lifting motor, D x It is the span between the system support points.

5. The ultra-large aperture sub-aperture stitching collimation system according to claim 1, characterized in that: Tilt angle adjustment range is ±2 ° .

6. The ultra-large aperture sub-aperture stitching collimation system according to claim 1, characterized in that: The plane mirror assembly (1) realizes unloading support of a 2m-diameter plane mirror in a mirror-face-down state. With the support of the mirror support structure, the plane mirror can ensure that the surface RMS value of the plane mirror in a vertical state of the optical axis is better than 0.03λ, where λ is the wavelength of the test light source.

7. The ultra-large aperture sub-aperture stitching collimation system according to claim 1, characterized in that: The splicing adjustment mechanism (2) has four-dimensional electric adjustment capability, including two-dimensional tilt angle adjustment and two-dimensional translation adjustment capability. The splicing adjustment mechanism can meet the splicing detection requirements within a 3.2m diameter, and the splicing accuracy can reach 0.05mm.

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