A space-grade far-field rendezvous and docking TOF optical system

Abstract

This invention discloses a space-grade far-field rendezvous and docking TOF optical system, comprising: a first lens group, an aperture stop, a second lens group, and an imaging plane; the first lens group is located near the object side to focus and converge incident light rays; the first lens group includes: a first plano-convex lens, a first positive meniscus lens, and a first negative meniscus lens arranged sequentially from the object side to the aperture stop; the aperture stop is located on the side of the first lens group away from the object side to adjust the luminous flux of the light rays passing through the first lens group; the second lens group is located on the image side to further process the light rays passing through the aperture stop; the second lens group includes: a second positive meniscus lens, a second plano-convex lens, a first biconvex lens, a first filter, and a second negative meniscus lens arranged sequentially from the aperture stop to the image side; the imaging plane is used to project and image the light rays passing through the second lens group. The optical system provided by this invention features a large field of view, low distortion, high resolution, and long working distance, enabling high-precision imaging of far-field targets.

Description

Technical Field

[0001] This invention relates to the field of imaging lens technology, and in particular to a space-grade far-field rendezvous and docking TOF optical system. Background Technology

[0002] Space rendezvous and docking technology has attracted increasing attention due to its crucial role in the construction of large space stations, the provision of personnel and supplies, and the transport of scientific research equipment. Among these technologies, optical rendezvous and docking technology involves first imaging a target using an optical system, then measuring the position of its image's centroid, and finally calculating the relative attitude of the target spacecraft and the tracking spacecraft. This optical rendezvous and docking technology boasts advantages such as high aiming accuracy, strong anti-interference capabilities, low accident risk, and the ability to operate unmanned. However, my country's research in this field started relatively late, and developing optical rendezvous and docking technology is urgently needed to keep pace with international advancements in this area.

[0003] Currently, the development of far-field rendezvous and docking optical systems for spacecraft based on Time-of-Flight (TOF) imaging technology faces numerous challenges, failing 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, there is an urgent need to develop a space-grade far-field rendezvous and docking TOF optical system to address these issues. Summary of the Invention

[0004] The purpose of this invention is to provide an aerospace-grade far-field rendezvous and docking TOF optical system that 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 objectives, the present invention provides a space-grade far-field rendezvous and docking TOF optical system, comprising:

[0006] First lens group, aperture stop, second lens group, and imaging plane;

[0007] The first lens group is located near the object side to focus and converge the incident light rays; the first lens group includes: a first plano-convex lens, a first positive meniscus lens, and a first negative meniscus lens arranged sequentially from the object side to the aperture.

[0008] The aperture is located on the 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 disposed on the image side and further processes the light passing through the aperture to improve the image quality; the second lens group includes: a second positive meniscus lens, a second plano-convex lens, a first biconvex lens, a first filter and a second negative meniscus lens arranged sequentially from the aperture to the image side.

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

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

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

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

[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; and 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 901 p / mm, the optical transfer function of the optical system is greater than 0.45 when the object is 10 m away, and greater than 0.1 when the object is 70 m away.

[0018] Optionally, when the object is 10 meters away, the RMS of the diffuse spot of the optical system is less than 2 μm; when the object is 70 meters away, the RMS 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 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 an aerospace-grade far-field rendezvous and docking TOF optical system. By cooperating with multiple positive and negative meniscus lenses, multiple convex lenses and filters, the difficulty of correcting aberrations in the overall optical system is reduced. At the same time, by utilizing the first lens group with a smaller number of lenses and the aperture stop, the aperture of the lens is rapidly reduced after the light from the large field of view enters the lens, thereby effectively controlling the lateral size of the lens. This achieves the miniaturization and weight reduction of the lens of the far-field rendezvous and docking TOF optical system.

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

[0023] 3. The present invention provides an aerospace-grade far-field rendezvous and docking TOF optical system, which can realize high-precision imaging of far-field targets and has a guiding role in improving the imaging accuracy of far-field rendezvous and docking TOF cameras. Attached Figure Description

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

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

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

[0027] Figure 4 This is a point diagram of the optical system of the present invention located at 10 meters;

[0028] Figure 5 This is a point diagram of the optical system of the object of the present invention located at 70 meters;

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

[0030] Figure 7 Figure (a) shows the field curvature diagram of the optical system of the present invention located at 70 meters. Figure 7 Figure (b) shows the relative distortion values ​​of the optical system at a distance of 70 meters from the object of the present invention. Detailed Implementation

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

[0032] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.

[0033] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] This invention provides a space-grade far-field rendezvous and docking TOF optical system, such as... Figure 1 As shown, the far-field rendezvous and docking TOF optical system includes: a first lens group 10, an aperture 80, a second lens group 20, and an imaging plane 90 arranged sequentially from the object side to the image side, i.e., from left to right in the figure. The first lens group 10 is the part of the far-field rendezvous and docking TOF optical system closest to the object, realizing the focusing and convergence of incident light rays; the aperture 80 can adjust the light flux of the light rays passing through the first lens group 10; the second lens group 20 further processes the light rays passing through the aperture 80 to improve the image quality; and the imaging plane 90 is used to project the light rays 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 7.45mm-10.61mm. Further, the air gap between the first lens group 10 and the aperture 80 is 1.8mm-2.6mm; the air gap between the aperture 80 and the second lens group 20 is 5.65mm-8.01mm.

[0037] Among them, such as 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, disposed on the side of the first plano-convex lens 71 away from the object side; and a first negative meniscus lens 31, disposed on the side of the first positive meniscus lens 41 away from the object side. Therefore, the first plano-convex lens 71, the first positive meniscus lens 41, and the first negative meniscus lens 31 are sequentially arranged from the object side to the aperture stop 80.

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

[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 lenses are made of high-transmittance spherical glass. Preferably, the spherical lenses of the present invention are made of fused silica and ZF6 glass materials, and without coating, the average transmittance of the optical system is higher than 75%.

[0040] Among them, such as Figure 1 As shown, the second lens group 20 includes: a second positive meniscus lens 42, disposed on the side of the aperture stop 80 away from the object side; a second plano-convex lens 72, disposed on the side of the second positive meniscus lens 42 away from the object side; a first biconvex lens 51, disposed on the side of the second plano-convex lens 72 away from the object side; a first filter 61, disposed on the side of the first biconvex lens 51 away from the object side; and a second negative meniscus lens 32, disposed on the side of the first filter 61 away from the object side. Therefore, from the aperture stop 80 to the imaging plane 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 sequentially.

[0041] 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; and 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. Furthermore, the spherical lenses are made of high-transmittance spherical glass. Preferably, the spherical lenses of the present invention are made of fused silica and ZF6 glass materials, and without coating, the average transmittance of the optical system is higher than 75%.

[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. Specifically, the air gap between the first lens group 10 and the aperture stop 80 is 2.2 mm; the air gap between the aperture stop 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; and 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 As shown. Figure 2 This indicates that when the object is located at a distance of 10 meters, the optical transfer function of this far-field rendezvous and docking TOF optical system is greater than 0.45. Figure 3 This indicates that when the object is located at 70 meters, the optical transfer function of this far-field rendezvous and docking TOF optical system is greater than 0.1.

[0045] like Figure 4 and Figure 5 The figures shown are point diagrams of the far-field rendezvous and docking TOF optical system when the object is at a distance of 10 meters and 70 meters, respectively. Figure 4 This indicates that when the object is 10 meters away, the RMS radius of the blur spot on the imaging plane 90 is less than 2 μm; Figure 5 This indicates that when the object is 70 meters away, the RMS radius of the blur spot is less than 13 μm; the above results show that the blur spot shape of the imaging plane 90 of the far-field rendezvous and docking TOF optical system is good.

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

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

[0048] Therefore, when the object is 10 meters and 70 meters away, the field curvature 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 far-field rendezvous and docking TOF optical system provided by this invention exhibits particularly outstanding optical performance when the object is 10 meters away. Specifically, its optical transfer function is greater than 0.45, the RMS spot radius is less than 2 μm, the field curvature is less than 0.1 mm, and the relative distortion is less than 0.5%.

[0050] In summary, the far-field rendezvous and docking TOF optical system possesses the following characteristics: optical transfer function (OTF) greater than 0.1 for each field of view (especially greater than 0.45 when the object is located at 10 meters); RMS spot radius less than 13 μm (especially less than 2 μm when the object is located at 10 meters); field curvature less than 0.1 mm; and relative distortion not exceeding 0.5%. Furthermore, the global surface lens configuration provides the conditions for mass production of this far-field rendezvous and docking TOF optical system.

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

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

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

[0054] 3) Spectral range: 850nm ± 10nm;

[0055] 4) Resolution: Achieve imaging quality comparable to a 2 / 3-inch SmartSens 350 detector (3 megapixels, 4.2μm pixel imaging);

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

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

[0058] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A space-grade far-field rendezvous and docking TOF optical system, characterized in that, The optical system consists of a first lens group (10), an aperture (80), a second lens group (20), and an imaging plane (90); The first lens group (10) is close to the object side to focus and converge the incident light rays; the first lens group (10) is composed of a first plano-convex lens (71), a first positive meniscus lens (41) and a first negative meniscus lens (31) arranged sequentially from the object side to the aperture (80); The aperture (80) is disposed on the side of the first lens group (10) away from the object side, and is used to adjust the light flux of the light passing through the first lens group (10); The second lens group (20) is disposed on the image side and further processes the light passing through the aperture (80) to improve the image quality; the second lens group (20) is composed of 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) arranged sequentially from the aperture (80) to the image side. The imaging surface (90) is used to project and image the light rays passing through the second lens group (20); The air gap between the first lens group (10) and the second lens group (20) is 7.45mm-10.61mm; The air gap between the first plano-convex lens (71) and the first positive meniscus lens (41) is 0.37mm-0.63mm; the air gap between the first positive meniscus lens (41) and the first negative meniscus lens (31) is 0.76mm-1.12mm. 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; and the air gap between the first filter (61) and the second negative meniscus lens (32) is 2.7mm-4.3mm. The first positive meniscus lens (41) bends toward the object side; the first negative meniscus lens (31) bends toward the object side; the second positive meniscus lens (42) bends toward the image side; and the second negative meniscus lens (32) bends toward the image side.

2. The far-field rendezvous and docking TOF optical system as described in claim 1, characterized in that, The air gap between the first lens group (10) and the aperture (80) is 1.8mm-2.6mm; the air gap between the aperture (80) and the second lens group (20) is 5.65mm-8.01mm.

3. The far-field rendezvous and docking TOF optical system as described in 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.

4. The far-field rendezvous and docking TOF optical system as described in 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.

5. The far-field rendezvous and docking TOF optical system as described in claim 1, characterized in that, With an object height of 8 mm and a spatial frequency of 901 p / mm, the optical transfer function of the optical system is greater than 0.45 when the object is 10 m away and greater than 0.1 when the object is 70 m away.

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

7. The far-field rendezvous and docking TOF optical system as described in claim 1, characterized in that, When the object is 10 meters and 70 meters away, the field curvature 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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