Astronavigation-level near-field rendezvous and docking TOF optical system

Abstract

The aerospace-level near-field rendezvous and docking TOF optical system comprises an object side surface lens group, a diaphragm, an image side surface lens group and a photosensitive imaging surface which are sequentially arranged from an object side surface to an image side surface, the object side surface lens group contracts the aperture of the incident light; the diaphragm is used for adjusting the luminous flux by adjusting the size of an aperture formed in the diaphragm; the image side surface lens group further focuses the light, corrects aberration, and then projects the light onto a photosensitive imaging surface to form a final image; the object side surface lens group comprises a first negative meniscus lens, a second negative meniscus lens, a first biconvex lens and a first positive meniscus lens which are sequentially arranged from the object side surface to the image side surface; and the image side surface lens group comprises a first optical filter, a third negative meniscus lens, a second positive meniscus lens, a second biconvex lens, a first plano-convex lens and a first plano-concave lens which are sequentially arranged from the object side surface to the image side surface. The optical system provided by the invention can realize high-precision imaging of a near-field target, and has a guiding effect on improvement of imaging precision in rendezvous and docking.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an aerospace-grade near-field rendezvous and docking TOF optical system. Background Art

[0002] Space rendezvous and docking technology is gaining increasing attention due to its important role in building large space stations, providing personnel and material supplies, and transporting scientific research instruments. Among them, optical rendezvous and docking technology uses an optical system to image the target, measure the position of its imaging center of mass, and then calculate the relative attitude of the target spacecraft and the tracking spacecraft. This technology has the advantages of high aiming accuracy, strong anti-interference ability, low accident risk, and unmanned operation. my country started research in this field relatively late. In order to keep up with the development of international space rendezvous and docking, it is urgent to carry out research in related fields.

[0003] At present, there are many difficulties in the development of near-field rendezvous and docking optical systems for spacecraft based on TOF (time of flight) imaging technology, and it is impossible to achieve the technical goals of high resolution, large field of view, high imaging quality, low distortion and high-precision imaging of near-field targets.

[0004] Therefore, there is an urgent need to develop a space-grade near-field rendezvous and docking optical system that can overcome the above-mentioned technical defects. Summary of the invention

[0005] The purpose of the present invention is to provide a space-grade near-field rendezvous and docking TOF optical system, which can solve the problems of low resolution, small field of view, low imaging quality and large distortion in near-field rendezvous and docking.

[0006] To achieve the above object, the present invention provides a space-grade near-field rendezvous and docking TOF optical system, comprising:

[0007] An object side lens group, an aperture, an image side lens group and a photosensitive imaging surface are arranged in sequence from the object side to the image side;

[0008] The object side lens group shrinks the incident light;

[0009] The aperture is provided with an adjustable aperture structure, and the light flux can be adjusted by adjusting the size of the aperture;

[0010] The image side lens group further focuses the light passing through the object side lens group, corrects the aberration, and then projects the light onto the photosensitive imaging surface for exposure to form a final image;

[0011] Wherein, the object side lens group comprises: a first negative meniscus lens, a second negative meniscus lens, a first biconvex lens and a first positive meniscus lens arranged in sequence from the object side to the image side;

[0012] The image side lens group includes: a first filter, a third negative meniscus lens, a second positive meniscus lens, a second biconvex lens, a first plano-convex lens and a first plano-concave lens, which are arranged in sequence from the object side to the image side.

[0013] Optionally, the air gap between the object side lens group and the image side lens group is 6.33 mm-9.27 mm.

[0014] Optionally, the air gap between the object side lens group and the aperture is 6.33 mm-9.17 mm.

[0015] Optionally, the air gap between the aperture and the image side lens group is 0mm-0.1mm.

[0016] Optionally, the air gap between the first negative meniscus lens and the second negative meniscus lens is 5.64mm-7.44mm; the air gap between the second negative meniscus lens and the first biconvex lens is 6.17mm-8.73mm; the air gap between the first biconvex lens and the first positive meniscus lens is 2.45mm-3.83mm.

[0017] Optionally, the air gap between the first filter and the third negative meniscus lens is 6.86mm-10.18mm; the air gap between the third negative meniscus lens and the second positive meniscus lens is 0.37mm-0.57mm; the air gap between the second positive meniscus lens and the second biconvex lens is 0.25mm-0.37mm; the air gap between the second biconvex lens and the first plano-convex lens is 0.25mm-0.35mm; the air gap between the first plano-convex lens and the first plano-concave lens is 2.18mm-3.66mm.

[0018] Optionally, the first negative meniscus lens, the second negative meniscus lens, the first biconvex lens and the first positive meniscus lens are all spherical lenses.

[0019] Optionally, the first filter, the third negative meniscus lens, the second positive meniscus lens, the second biconvex lens, the first plano-convex lens and the first plano-concave lens are all spherical lenses.

[0020] Optionally, when the object height is 8 mm and the spatial frequency is 50 lp / mm, when the object is 1 m away, the optical transfer function of the optical system is greater than 0.4; when the object is 2 m away, the optical transfer function of the optical system is greater than 0.6; when the object is 10 m away, the optical transfer function of the optical system is greater than 0.4.

[0021] Optionally, when the object is 2 m away, the optical transfer function of the optical system is greater than 0.6, the edge relative illumination is greater than 50%, the RMS radius of the diffuse spot is less than 4 μm, the field curvature is less than 0.15 mm, and the relative distortion is less than 1.5%.

[0022] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention provides a space-grade near-field rendezvous and docking TOF optical system, which effectively shrinks the aperture of incident light with a large field of view through the object side lens group through the cooperation of multiple positive and negative meniscus lenses, multiple concave and convex lenses and filters, and reduces the difficulty of correcting aberrations of the image side lens group, while achieving the miniaturization and lightweight of the near-field rendezvous and docking TOF optical system lens.

[0024] 2. The present invention provides a space-grade near-field rendezvous and docking TOF optical system, which has the characteristics of large field of view, low distortion, high resolution, long working distance and uniform relative illumination.

[0025] 3. The aerospace-grade near-field rendezvous and docking TOF optical system provided by the present invention can achieve high-precision imaging of near-field targets and play a guiding role in improving imaging accuracy during the rendezvous and docking process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the composition of the optical system of the present invention;

[0027] Figure 2 is an optical transfer function diagram of an optical system of the present invention when an object is located at 1 meter;

[0028] Figure 3 The optical transfer function diagram of the optical system of the present invention when the object is located at 2 meters;

[0029] Figure 4 The optical transfer function diagram of the optical system of the present invention when the object is located at 10 meters;

[0030] Figure 5 The relative illumination diagram of the optical system of the present invention when the object is located at 1 meter;

[0031] Figure 6 The relative illumination diagram of the optical system of the present invention when the object is located at 2 meters;

[0032] Figure 7 This is a relative illumination diagram of the optical system of the present invention when the object is located at 10 meters;

[0033] Figure 8 The optical system spot diagram of the present invention when the object is located at 1 meter;

[0034] Fig. 9 The optical system spot diagram of the present invention when the object is located at 2 meters;

[0035] Fig.10 The optical system spot diagram of the present invention when the object is located at 10 meters;

[0036] Fig.11 Figure (a) is a field curvature diagram of the optical system of the present invention when the object is located at 1 meter; Fig.11 Figure (b) is a relative distortion value diagram of the present invention when the object is located at 1 meter;

[0037] Fig.12 Figure (a) is a field curvature diagram of the optical system of the present invention when the object is located at 2 meters; Fig.12 Figure (b) is a relative distortion value diagram of the present invention when the object is located at 2 meters;

[0038] Fig.13 Figure (a) is a field curvature diagram of the optical system of the present invention when the object is located at 10 meters; Fig.13 Figure (b) is a relative distortion value diagram of the object of the present invention when it is located at 10 meters. DETAILED DESCRIPTION

[0039] The following will be combined with the attached Figures 1 to 13 , the technical content, structural features, objectives achieved and effects of the present invention are described in detail through preferred embodiments.

[0040] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0041] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The present invention provides a space-grade near-field rendezvous and docking TOF optical system, such as Figure 1 As shown, the near-field rendezvous TOF optical system comprises: an object side lens group 10, an aperture 90, an image side lens group 20 and a photosensitive imaging surface 100, which are arranged in sequence from the object side to the image side, that is, from the left side to the right side of the figure. The object side lens group 10 is the part closest to the object in the near-field rendezvous TOF optical system, and can shrink the aperture of the incident light; the aperture 90 is provided with an adjustable aperture structure, and the light flux can be adjusted by adjusting the size of the aperture; the image side lens group 20 further focuses the light passing through the object side lens group 10, corrects the aberration, and then projects it onto the photosensitive imaging surface (100) for light exposure and forms a final image.

[0044] The air gap between the object side lens group 10 and the image side lens group 20 is 6.33 mm to 9.27 mm. Furthermore, the air gap between the object side lens group 10 and the aperture 90 is 6.33 mm to 9.17 mm; and the air gap between the aperture 90 and the image side lens group 20 is 0 mm to 0.1 mm.

[0045] The object side lens group 10 includes: a first negative meniscus lens 31, which is the lens closest to the object side; a second negative meniscus lens 32, which is arranged on the side of the first positive meniscus lens 31 away from the object side; a first biconvex lens 51, which is arranged on the side of the second negative meniscus lens 32 away from the object side; and a first positive meniscus lens 41, which is arranged on the side of the first biconvex lens 51 away from the object side. Therefore, from the object side to the aperture 90, the first negative meniscus lens 31, the second negative meniscus lens 32, the first biconvex lens 51 and the first positive meniscus lens 41 are arranged in sequence.

[0046] Among them, the air gap between the first negative meniscus lens 31 and the second negative meniscus lens 32 is 5.64mm-7.44mm; the air gap between the second negative meniscus lens 32 and the first biconvex lens 51 is 6.17mm-8.73mm; the air gap between the first biconvex lens 51 and the first positive meniscus lens 41 is 2.45mm-3.83mm.

[0047] In a specific embodiment of the present invention, the first negative meniscus lens 31, the second negative meniscus lens 32, the first biconvex lens 51 and the first positive meniscus lens 41 are all spherical lenses. Further, the spherical lens adopts a spherical glass lens with high transmittance. Preferably, the spherical lens of the present invention is made of glass materials such as fused quartz and calcium fluoride, and the average transmittance of the optical system is higher than 75% without coating.

[0048] The image side lens group 20 includes: a first filter 61, which is arranged on the side of the aperture 90 away from the object side; a third negative meniscus lens 33, which is arranged on the side of the first filter 61 away from the object side; a second positive meniscus lens 42, which is arranged on the side of the third negative meniscus lens 33 away from the object side; a second biconvex lens 52, which is arranged on the side of the second positive meniscus lens 42 away from the object side; a first plano-convex lens 71, which is arranged on the side of the second biconvex lens 52 away from the object side; and a first plano-concave lens 81, which is arranged on the side of the first plano-convex lens 71 away from the object side. Therefore, from the aperture 90 to the photosensitive imaging surface 100, the first filter 61, the third negative meniscus lens 33, the second positive meniscus lens 42, the second biconvex lens 52, the first plano-convex lens 71 and the first plano-concave lens 81 are arranged in sequence.

[0049] Among them, the air gap between the first filter 61 and the third negative meniscus lens 33 is 6.86mm-10.18mm; the air gap between the third negative meniscus lens 33 and the second positive meniscus lens 42 is 0.37mm-0.57mm; the air gap between the second positive meniscus lens 42 and the second biconvex lens 52 is 0.25mm-0.37mm; the air gap between the second biconvex lens 52 and the first plano-convex lens 71 is 0.25mm-0.35mm; the air gap between the first plano-convex lens 71 and the first plano-concave lens 81 is 2.18mm-3.66mm.

[0050] In a specific embodiment of the present invention, the first filter 61, the third negative meniscus lens 33, the second positive meniscus lens 42, the second biconvex lens 52, the first plano-convex lens 71 and the first plano-concave lens 81 are all spherical lenses. Further, the spherical lens adopts a spherical glass lens with high transmittance. Preferably, the spherical lens of the present invention is made of glass materials such as fused quartz and calcium fluoride, and the average transmittance of the optical system is higher than 75% without coating.

[0051] In a more specific embodiment, the air gap between the object side lens group 10 and the image side lens group 20 is 7.75 mm. The air gap between the object side lens group 10 and the diaphragm 90 is 7.75 mm; the air gap between the diaphragm 90 and the image side lens group 20 is 0 mm, that is, the diaphragm 90 and the image side lens group 20 are in contact. Further, the air gap between the first negative meniscus lens 31 and the second negative meniscus lens 32 is 6.54 mm; the air gap between the second negative meniscus lens 32 and the first biconvex lens 51 is 7.45 mm; the air gap between the first biconvex lens 51 and the first positive meniscus lens 41 is 3.14 mm. The air gap between the first filter 61 and the third negative meniscus lens 33 is 8.52 mm; the air gap between the third negative meniscus lens 33 and the second positive meniscus lens 42 is 0.47 mm; the air gap between the second positive meniscus lens 42 and the second biconvex lens 52 is 0.31 mm; the air gap between the second biconvex lens 52 and the first plano-convex lens 71 is 0.30 mm; the air gap between the first plano-convex lens 71 and the first plano-concave lens 81 is 2.92 mm.

[0052] In a specific embodiment of the present invention, when the object height is 8 mm and the spatial frequency is 50 lp / mm, the optical transfer function of the near-field rendezvous and docking TOF optical system is as follows: Figure 2 , Figure 3 and Figure 4 shown. Figure 2 It shows that when the object is located at 1 meter, the optical transfer function of the near-field rendezvous and docking TOF optical system is greater than 0.4; Figure 3 It shows that when the object is at a distance of 2 meters, the optical transfer function of the near-field rendezvous and docking TOF optical system is greater than 0.6; Figure 4 It shows that when the object is located at 10 meters, the optical transfer function of the near-field rendezvous and docking TOF optical system is greater than 0.4.

[0053] When the object is at 1 meter, 2 meters, and 10 meters, the relative illumination values ​​of the optical system of the present invention are respectively as follows: Figure 5 , Figure 6 and Figure 7 As shown, it can be seen that under the near-field rendezvous and docking TOF optical system, the relative illumination of the photosensitive imaging surface 100 remains uniform, and the relative illumination at the edges is greater than 50%.

[0054] like Figure 8 , Fig. 9 and Fig.10As shown, they are the spot diagrams of the near-field rendezvous and docking TOF optical system when the object is at 1 meter, 2 meters and 10 meters. These spot diagrams show that the RMS radius of the diffuse spot of the photosensitive imaging surface 100 is less than 10μm, especially when the object is at 2 meters, the RMS radius of the diffuse spot is less than 4μm; the above results show that the shape of the diffuse spot of the photosensitive imaging surface 100 of the near-field rendezvous and docking TOF optical system is good.

[0055] Fig.11 Figure (a) is a field curvature diagram of the near-field rendezvous and docking TOF optical system when the object is 1 meter away. Fig.11 Figure (b) shows the relative distortion value of the near-field rendezvous and docking TOF optical system when the object is 1 meter away. Fig.11 As can be seen from Figure (a), the field curvature of the optical system is less than 0.15 mm. Fig.11 As can be seen from Figure (b), the relative distortion value of the optical system does not exceed 1.5%.

[0056] Fig.12 Figure (a) is a field curvature diagram of the near-field rendezvous and docking TOF optical system when the object is 2 meters away. Fig.12 Figure (b) shows the relative distortion value of the near-field rendezvous and docking TOF optical system when the object is 2 meters away. Fig.12 As can be seen from Figure (a), the field curvature of the optical system is less than 0.15 mm. Fig.12 As can be seen from Figure (b), the relative distortion value of the optical system does not exceed 1.5%.

[0057] Fig.13 Figure (a) is a field curvature diagram of the near-field rendezvous and docking TOF optical system when the object is 10 meters away. Fig.13 Figure (b) shows the relative distortion value of the near-field rendezvous and docking TOF optical system when the object is 10 meters away. Fig.13 As can be seen from Figure (a), the field curvature of the optical system is less than 0.15 mm. Fig.13 As can be seen from Figure (b), the relative distortion value of the optical system does not exceed 1.5%.

[0058] Therefore, when the object is 1 meter, 2 meters and 10 meters away, the field curvature value of the near-field rendezvous and docking TOF optical system is less than 0.15 mm, and the relative distortion value does not exceed 1.5%.

[0059] The near-field rendezvous and docking TOF optical system provided by the present invention has particularly outstanding optical performance when the object is 2 meters away, which is specifically manifested as: its optical transfer function is greater than 0.6, the relative illumination of the photosensitive imaging surface 100 is uniform, the edge relative illumination is greater than 50%, and the relative distortion value is less than 1.5%.

[0060] In summary, the near-field rendezvous and docking TOF optical system has the characteristics of optical transfer functions of each field of view being greater than 0.4 (especially when the object is located at 2 meters, the optical transfer function is greater than 0.6), relative illumination being greater than 50%, diffuse spot radius RMS being less than 10 μm (especially when the object is located at 2 meters, the diffuse spot radius RMS being less than 4 μm), field curvature being less than 0.15 mm, and relative distortion value being no more than 1.5%. In addition, the setting of the full spherical lens also provides conditions for the mass production of the near-field rendezvous and docking TOF optical system.

[0061] In addition, the near-field rendezvous and docking TOF optical system has the following optical indicators:

[0062] 1) Relative aperture: D / f′=1 / 5 (i.e., the image-side F number is 5), where D is the lens entrance pupil diameter and f′ is the lens focal length;

[0063] 2) Large field of view: 2ω=78°, where ω is the half field of view;

[0064] 3) Spectral range: 850nm±10nm;

[0065] 4) Resolution: The imaging quality reaches that of the 2 / 3-inch SmartSens 350 detector (3 million pixels, 4.2μm pixel imaging);

[0066] 5) Working distance: When the spatial frequency is 50lp / mm, the working distance is 0.8 meters to ∞.

[0067] In summary, the aerospace-grade near-field rendezvous and docking TOF optical system provided by the present invention has the excellent performance of large field of view, low distortion, high resolution, long working distance and uniform relative illumination; in addition, it can be used in conjunction with various 2 / 3-inch high-definition megapixel detectors such as 16:9 and 5:4, and can achieve low cost requirements and mass production purposes.

[0068] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the invention. After reading the above content, it will be obvious to those skilled in the art for various modifications and substitutions of the present invention. Therefore, the protection scope of the present invention should be limited by the attached claims.

Claims

1. A space-grade near-field rendezvous and docking TOF optical system, characterized in that: include: An object side lens group (10), an aperture (90), an image side lens group (20) and a photosensitive imaging surface (100) are arranged in sequence from the object side to the image side; The object side lens group (10) shrinks the aperture of the incident light; The aperture (90) is provided with an adjustable aperture structure, and the light flux is adjusted by adjusting the aperture size; The image side lens group (20) further focuses the light passing through the object side lens group (10), corrects the aberration, and then projects the light onto the photosensitive imaging surface (100) for light exposure and forms a final image; The object side lens group (10) comprises: a first negative meniscus lens (31), a second negative meniscus lens (32), a first biconvex lens (51) and a first positive meniscus lens (41) which are arranged in sequence from the object side to the image side; The image side lens group (20) comprises: a first filter (61), a third negative meniscus lens (33), a second positive meniscus lens (42), a second biconvex lens (52), a first plano-convex lens (71) and a first plano-concave lens (81) which are arranged in sequence from the object side to the image side.

2. The near-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The air gap between the object side lens group (10) and the image side lens group (20) is 6.33 mm to 9.27 mm.

3. The near-field rendezvous and docking TOF optical system according to claim 2, characterized in that: The air gap between the object side lens group (10) and the aperture (90) is 6.33 mm to 9.17 mm.

4. The near-field rendezvous and docking TOF optical system according to claim 3, characterized in that: The air gap between the aperture (90) and the image side lens group (20) is 0 mm-0.1 mm.

5. The near-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The air gap between the first negative meniscus lens (31) and the second negative meniscus lens (32) is 5.64 mm-7.44 mm; the air gap between the second negative meniscus lens (32) and the first biconvex lens (51) is 6.17 mm-8.73 mm; and the air gap between the first biconvex lens (51) and the first positive meniscus lens (41) is 2.45 mm-3.83 mm.

6. The near-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The air gap between the first filter (61) and the third negative meniscus lens (33) is 6.86 mm-10.18 mm; the air gap between the third negative meniscus lens (33) and the second positive meniscus lens (42) is 0.37 mm-0.57 mm; the air gap between the second positive meniscus lens (42) and the second biconvex lens (52) is 0.25 mm-0.37 mm; the air gap between the second biconvex lens (52) and the first plano-convex lens (71) is 0.25 mm-0.35 mm; the air gap between the first plano-convex lens (71) and the first plano-concave lens (81) is 2.18 mm-3.66 mm.

7. The near-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The first negative meniscus lens (31), the second negative meniscus lens (32), the first biconvex lens (51) and the first positive meniscus lens (41) are all spherical lenses.

8. The near-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The first optical filter (61), the third negative meniscus lens (33), the second positive meniscus lens (42), the second biconvex lens (52), the first plano-convex lens (71) and the first plano-concave lens (81) are all spherical lenses.

9. The near-field rendezvous and docking TOF optical system according to claim 1, characterized in that: When the object height is 8 mm and the spatial frequency is 50 lp / mm, when the object is 1 m away, the optical transfer function of the optical system is greater than 0.4; when the object is 2 m away, the optical transfer function of the optical system is greater than 0.6; when the object is 10 m away, the optical transfer function of the optical system is greater than 0.

4.

10. The near-field rendezvous and docking TOF optical system according to claim 1, characterized in that: When the object is 2 meters away, the optical transfer function of the optical system is greater than 0.6, the edge relative illumination is greater than 50%, the RMS of the diffuse spot radius is less than 4 μm, the field curvature value is less than 0.15 mm, and the relative distortion value is less than 1.5%.

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