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

Abstract

The invention discloses an astronavigation-level far-field rendezvous and docking TOF optical system, which comprises a first lens group, a diaphragm, a second lens group and an imaging surface, the first lens group is close to the object side surface and gathers and gathers incident light; the first lens group comprises a first plano-convex lens, a first positive meniscus lens and a first negative meniscus lens which are sequentially arranged from the object side surface to the diaphragm; the diaphragm is arranged on one side, far away from the object side surface, of the first lens group and is used for adjusting the luminous flux of the light passing through the first lens group; the second lens group is arranged on the image side surface and further processes the light passing through the diaphragm; the second lens group comprises a second positive meniscus lens, a second plano-convex lens, a first biconvex lens, a first optical filter and a second negative meniscus lens which are sequentially arranged from the diaphragm to the image side surface; and the imaging surface is used for projecting and imaging the light passing through the second lens group. The optical system provided by the invention has the characteristics of large field of view, low distortion, high resolution and long working distance, and can realize high-precision imaging of a far-field target.

Description

Technical Field

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

[0002] Space rendezvous and docking technology has attracted increasing attention due to its important role in the construction of large space stations, providing personnel and material supplies, and transporting scientific research equipment. Among them, optical rendezvous and docking technology is a technology that first images the target through an optical system, then measures the position of its imaging center of mass, and then calculates the relative posture of the target spacecraft and the tracking spacecraft. This optical rendezvous and docking technology has the advantages of high aiming accuracy, strong anti-interference ability, low accident risk, and unmanned operation. However, my country's research work in this field started relatively late. In order to keep up with the pace of international space rendezvous and docking development, it is urgent to develop optical rendezvous and docking technology.

[0003] At present, there are many difficulties in the development of spacecraft far-field rendezvous and docking optical systems 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 far-field targets. Therefore, it is urgent to develop an aerospace-grade far-field rendezvous and docking TOF optical system to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a space-grade far-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 far-field rendezvous and docking.

[0005] To achieve the above object, the present invention provides a space-grade far-field rendezvous and docking TOF optical system, comprising:

[0006] A first lens group, an aperture, a second lens group and an imaging surface;

[0007] The first lens group is close to the object side and gathers and converges the incident light; the first lens group comprises: a first plano-convex lens, a first positive meniscus lens and a first negative meniscus lens which are arranged in sequence from the object side to the aperture;

[0008] The aperture is arranged on a side of the first lens group away from the object side, and is used to adjust the luminous flux of the light passing through the first lens group;

[0009] The second lens group is arranged on the image side, and further processes the light passing through the aperture to improve the imaging quality; the second lens group comprises: a second positive meniscus lens, a second plano-convex lens, a first biconvex lens, a first filter and a second negative meniscus lens, which are arranged in sequence from the aperture to the image side;

[0010] The imaging surface is used to project the light passing through the second lens group into an image.

[0011] Optionally, the air gap between the first lens group and the second lens group is 7.45 mm-10.61 mm.

[0012] Optionally, the air space between the first lens group and the aperture is 1.8 mm-2.6 mm; the air space between the aperture and the second lens group is 5.65 mm-8.01 mm.

[0013] Optionally, the air gap between the first plano-convex lens and the first positive meniscus lens is 0.37 mm-0.63 mm; the air gap between the first positive meniscus lens and the first negative meniscus lens is 0.76 mm-1.12 mm.

[0014] Optionally, the air gap between the second positive meniscus lens and the second plano-convex lens is 3.9mm-6.9mm; the air gap between the second plano-convex lens and the first biconvex lens is 0.47mm-0.73mm; the air gap between the first biconvex lens and the first filter is 1.6mm-2.4mm; the air gap between the first filter and the second negative meniscus lens is 2.7mm-4.3mm.

[0015] Optionally, the first plano-convex lens, the first positive meniscus lens and the first negative meniscus lens are all spherical lenses.

[0016] Optionally, the second positive meniscus lens, the second plano-convex lens, the first biconvex lens, the first filter and the second negative meniscus lens are all spherical lenses.

[0017] Optionally, when the object height is 8 mm and the spatial frequency is 901p / mm, when the object is 10 m away, the optical transfer function of the optical system is greater than 0.45; when the object is 70 m away, the optical transfer function of the optical system is greater than 0.1.

[0018] Optionally, when the object is 10 meters away, the RMS radius of the diffuse spot of the optical system is less than 2 μm; when the object is 70 meters away, the RMS radius of the diffuse spot of the optical system is less than 13 μm.

[0019] Optionally, when the object is 10 meters and 70 meters away, the field curvature value of the far-field rendezvous and docking TOF optical system is less than 0.1 mm, and the relative distortion value does not exceed 0.5%.

[0020] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention provides a space-grade far-field rendezvous and docking TOF optical system, which reduces the difficulty of correcting aberrations of the entire optical system by cooperating with multiple positive and negative meniscus lenses, multiple convex lenses and filters; at the same time, by cooperating with a first lens group and an aperture with a relatively small number of lenses, the aperture can be effectively contracted quickly after light of a large field of view enters the lens, thereby effectively controlling the lateral size of the lens, thereby realizing the miniaturization and lightweight of the lens of the far-field rendezvous and docking TOF optical system.

[0022] 2. The present invention provides a space-grade far-field rendezvous and docking TOF optical system, which has the characteristics of large field of view, low distortion, high resolution and long working distance.

[0023] 3. The aerospace-grade far-field rendezvous and docking TOF optical system provided by the present invention can achieve high-precision imaging of far-field targets and play a guiding role in improving the imaging accuracy of far-field rendezvous and docking TOF cameras. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the composition of the optical system of the present invention;

[0025] Figure 2 The optical transfer function diagram of the optical system of the present invention when the object is located at 10 meters;

[0026] Figure 3 The optical transfer function diagram of the optical system of the present invention when the object is located at 70 meters;

[0027] Figure 4 The optical system spot diagram of the present invention when the object is located at 10 meters;

[0028] Figure 5 The optical system spot diagram of the present invention when the object is located at 70 meters;

[0029] Figure 6 Figure (a) is a field curvature diagram of the optical system of the present invention where the object is located at 10 meters. Figure 6 Figure (b) is a diagram of relative distortion values ​​of the optical system of the present invention when the object is located at 10 meters;

[0030] Figure 7 Figure (a) is a field curvature diagram of the optical system of the present invention when the object is located at 70 meters. Figure 7 Figure (b) is a diagram of relative distortion values ​​of the optical system of the present invention when the object is located at 70 meters. DETAILED DESCRIPTION

[0031] The following will be combined with the attached Figures 1 to 7 , the technical content, structural features, objectives achieved and effects of the present invention are described in detail through preferred embodiments.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The present invention provides a space-grade far-field rendezvous and docking TOF optical system, such as Figure 1 As shown, the far-field rendezvous TOF optical system includes: a first lens group 10, an aperture 80, a second lens group 20 and an imaging surface 90, which are arranged in sequence from the object side to the image side, that is, from the left to the right side of the figure. The first lens group 10 is the part closest to the object in the far-field rendezvous TOF optical system, which realizes the gathering and convergence of the incident light; the aperture 80 can adjust the luminous flux of the light passing through the first lens group 10; the second lens group 20 further processes the light passing through the aperture 80 to improve the imaging quality; the imaging surface 90 is used to project the light passing through the second lens group 20 into an image.

[0036] The air gap between the first lens group 10 and the second lens group 20 is 7.45 mm to 10.61 mm. Furthermore, the air gap between the first lens group 10 and the aperture 80 is 1.8 mm to 2.6 mm; and the air gap between the aperture 80 and the second lens group 20 is 5.65 mm to 8.01 mm.

[0037] Among them, Figure 1 As shown, the first lens group 10 includes: a first plano-convex lens 71, which is the lens closest to the object side; a first positive meniscus lens 41, which is arranged on the side of the first plano-convex lens 71 away from the object side; and a first negative meniscus lens 31, which is arranged on the side of the first positive meniscus lens 41 away from the object side. Therefore, from the object side to the aperture 80, the first plano-convex lens 71, the first positive meniscus lens 41 and the first negative meniscus lens 31 are arranged in sequence.

[0038] The air gap between the first plano-convex lens 71 and the first positive meniscus lens 41 is 0.37 mm-0.63 mm; the air gap between the first positive meniscus lens 41 and the first negative meniscus lens 31 is 0.76 mm-1.12 mm.

[0039] In a specific embodiment of the present invention, the first plano-convex lens 71, the first positive meniscus lens 41 and the first negative meniscus lens 31 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 ZF6, and the average transmittance of the optical system is higher than 75% without coating.

[0040] Among them, Figure 1 As shown, the second lens group 20 includes: a second positive meniscus lens 42, which is arranged on the side of the aperture 80 away from the object side; a second plano-convex lens 72, which is arranged on the side of the second positive meniscus lens 42 away from the object side; a first biconvex lens 51, which is arranged on the side of the second plano-convex lens 72 away from the object side; a first filter 61, which is arranged on the side of the first biconvex lens 51 away from the object side; and a second negative meniscus lens 32, which is arranged on the side of the first filter 61 away from the object side. Therefore, from the aperture 80 to the imaging surface 90, the second positive meniscus lens 42, the second plano-convex lens 72, the first biconvex lens 51, the first filter 61 and the second negative meniscus lens 32 are arranged in sequence.

[0041] Among them, the air gap between the second positive meniscus lens 42 and the second plano-convex lens 72 is 3.9mm-6.9mm; the air gap between the second plano-convex lens 72 and the first biconvex lens 51 is 0.47mm-0.73mm; the air gap between the first biconvex lens 51 and the first filter 61 is 1.6mm-2.4mm; the air gap between the first filter 61 and the second negative meniscus lens 32 is 2.7mm-4.3mm.

[0042] In a specific embodiment of the present invention, the second positive meniscus lens 42, the second plano-convex lens 72, the first biconvex lens 51, the first filter 61 and the second negative meniscus lens 32 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 ZF6, and the average transmittance of the optical system is higher than 75% without coating.

[0043] In a more specific embodiment, the air gap between the first lens group 10 and the second lens group 20 is 9.03 mm. The air gap between the first lens group 10 and the aperture 80 is 2.2 mm; the air gap between the aperture 80 and the second lens group 20 is 6.83 mm. Further, the air gap between the first plano-convex lens 71 and the first positive meniscus lens 41 is 0.5 mm; the air gap between the first positive meniscus lens 41 and the first negative meniscus lens 31 is 0.94 mm. The air gap between the second positive meniscus lens 42 and the second plano-convex lens 72 is 5.4 mm; the air gap between the second plano-convex lens 72 and the first biconvex lens 51 is 0.6 mm; the air gap between the first biconvex lens 51 and the first filter 61 is 2 mm; the air gap between the first filter 61 and the second negative meniscus lens 32 is 3.5 mm.

[0044] In a specific embodiment of the present invention, when the object height is 8 mm and the spatial frequency is 90 lp / mm, the optical transfer function of the far-field rendezvous and docking TOF optical system is as follows: Figure 2 and Figure 3 shown. Figure 2 It shows that when the object is located at 10 meters, the optical transfer function of the far-field rendezvous and docking TOF optical system is greater than 0.45; Figure 3 It shows that when the object is located at 70 meters, the optical transfer function of the far-field rendezvous and docking TOF optical system is greater than 0.1.

[0045] like Figure 4 and Figure 5 As shown, they are the spot diagrams of the far-field rendezvous and docking TOF optical system when the object is at 10 meters and 70 meters. Figure 4 It shows that when the object is 10 meters away, the RMS radius of the diffuse spot on the imaging surface 90 is less than 2 μm; Figure 5 It shows that when the object is 70 meters away, the RMS radius of the diffuse spot is less than 13 μm. The above results show that the diffuse spot shape of the imaging surface 90 of the far-field rendezvous and docking TOF optical system is better.

[0046] Figure 6 Figure (a) is a field curvature diagram of the far-field rendezvous and docking TOF optical system when the object is 10 meters away. Figure 6Figure (b) shows the relative distortion value of the far-field rendezvous and docking TOF optical system when the object is 10 meters away. Figure 6 As can be seen from Figure (a), the field curvature of the optical system is less than 0.1 mm. Figure 6 As can be seen from Figure (b), the relative distortion value of the optical system does not exceed 0.5%.

[0047] Figure 7 Figure (a) is a field curvature diagram of the far-field rendezvous and docking TOF optical system when the object is 70 meters away. Figure 7 Figure (b) shows the relative distortion value of the far-field rendezvous and docking TOF optical system when the object is 70 meters away. Figure 7 As can be seen from Figure (a), the field curvature of the optical system is less than 0.1 mm. Figure 7 As can be seen from Figure (b), the relative distortion value of the optical system does not exceed 0.5%.

[0048] Therefore, when the object is 10 meters and 70 meters away, the field curvature value of the far-field rendezvous and docking TOF optical system is less than 0.1 mm, and the relative distortion value does not exceed 0.5%.

[0049] The optical performance of the far-field rendezvous and docking TOF optical system provided by the present invention is particularly outstanding when the object is 10 meters away, which is specifically manifested as: the optical transfer function is greater than 0.45, the RMS of the diffuse spot radius is less than 2μm, the field curvature value is less than 0.1mm, and the relative distortion value is less than 0.5%.

[0050] In summary, the far-field rendezvous and docking TOF optical system has the characteristics that the optical transfer function of each field of view is greater than 0.1 (especially when the object is located at 10 meters, the optical transfer function is greater than 0.45), the RMS radius of the diffuse spot is less than 13μm (especially when the object is located at 10 meters, the RMS radius of the diffuse spot is less than 2μm), the field curvature value is less than 0.1mm, and the relative distortion value does not exceed 0.5%. The setting of the full spherical lens also provides conditions for the mass production of the far-field rendezvous and docking TOF optical system.

[0051] In addition, the far-field rendezvous and docking TOF optical system has the following optical indicators:

[0052] 1) Relative aperture: D / f′=1 / 4.8 (i.e., the image-side F number is 4.8), where D is the lens entrance pupil diameter and f′ is the lens focal length;

[0053] 2) Large field of view: 2ω=30.6 o ， Where ω is the half field of view;

[0054] 3) Spectral range: 850nm±10nm;

[0055] 4) Resolution: The imaging quality reaches that of the 2 / 3-inch SmartSens 350 detector (3 million pixels, 4.2μm pixel imaging);

[0056] 5) Working distance: When the spatial frequency is 90lp / mm, the working distance is 6 meters to ∞.

[0057] In summary, the aerospace-grade far-field rendezvous and docking TOF optical system provided by the present invention has excellent performance such as large field of view, low distortion, high resolution, and long working distance; in addition, the far-field rendezvous and docking TOF optical system can also be used in conjunction with various standard 2 / 3-inch high-definition megapixel detectors such as 16:9 and 5:4, which can achieve the purpose of low cost requirements and mass production.

[0058] 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 far-field rendezvous and docking TOF optical system, characterized in that: It comprises: a first lens group (10), an aperture (80), a second lens group (20) and an imaging surface (90); The first lens group (10) is close to the object side and gathers and converges the incident light; the first lens group (10) comprises: a first plano-convex lens (71), a first positive meniscus lens (41) and a first negative meniscus lens (31) which are arranged in sequence from the object side to the aperture (80); The aperture (80) is arranged on a side of the first lens group (10) away from the object side, and is used to adjust the luminous flux of light passing through the first lens group (10); The second lens group (20) is arranged on the image side and further processes the light passing through the aperture (80) to improve the imaging quality; the second lens group (20) comprises: a second positive meniscus lens (42), a second plano-convex lens (72), a first biconvex lens (51), a first filter (61) and a second negative meniscus lens (32) which are arranged in sequence from the aperture (80) to the image side; The imaging surface (90) is used to project the light passing through the second lens group (20) into an image.

2. The far-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The air gap between the first lens group (10) and the second lens group (20) is 7.45 mm-10.61 mm.

3. The far-field rendezvous and docking TOF optical system according to claim 2, characterized in that: The air gap between the first lens group (10) and the aperture (80) is 1.8 mm to 2.6 mm; the air gap between the aperture (80) and the second lens group (20) is 5.65 mm to 8.01 mm.

4. The far-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The air gap between the first plano-convex lens (71) and the first positive meniscus lens (41) is 0.37 mm-0.63 mm; the air gap between the first positive meniscus lens (41) and the first negative meniscus lens (31) is 0.76 mm-1.12 mm.

5. The far-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The air gap between the second positive meniscus lens (42) and the second plano-convex lens (72) is 3.9 mm-6.9 mm; the air gap between the second plano-convex lens (72) and the first biconvex lens (51) is 0.47 mm-0.73 mm; the air gap between the first biconvex lens (51) and the first optical filter (61) is 1.6 mm-2.4 mm; the air gap between the first optical filter (61) and the second negative meniscus lens (32) is 2.7 mm-4.3 mm.

6. The far-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The first plano-convex lens (71), the first positive meniscus lens (41) and the first negative meniscus lens (31) are all spherical lenses.

7. The far-field rendezvous and docking TOF optical system according to claim 1, characterized in that: The second positive meniscus lens (42), the second plano-convex lens (72), the first biconvex lens (51), the first filter (61) and the second negative meniscus lens (32) are all spherical lenses.

8. The far-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 901p / mm, the optical transfer function of the optical system is greater than 0.45 when the object is 10 m away; and when the object is 70 m away, the optical transfer function of the optical system is greater than 0.

1.

9. The far-field rendezvous and docking TOF optical system according to claim 1, characterized in that: When the object is 10 meters away, the RMS radius of the diffuse spot of the optical system is less than 2 μm; when the object is 70 meters away, the RMS radius of the diffuse spot of the optical system is less than 13 μm.

10. The far-field rendezvous and docking TOF optical system according to claim 1, characterized in that: When the object is 10 meters and 70 meters away, the field curvature value of the far-field rendezvous and docking TOF optical system is less than 0.1 mm, and the relative distortion value does not exceed 0.5%.

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