High-precision navigation multi-optical field-of-view photoelectric system

Abstract

A multi-optical-view-field photoelectric system for high-precision navigation is composed of a plurality of optical view fields in different vector directions, a highly integrated design is adopted, a CCD / CMOS is shared to achieve control over a plurality of head vector directions, a plurality of off-axis optical systems sharing the same optical axis are integrated together, and the multi-optical-view-field photoelectric system is formed. And finally, optical information in multiple vector directions of the object space is converged on the same optical focal plane through the same rear light path optical system, and the imaging sky area range is expanded by adopting a plurality of heads with different direction vectors, so that high-precision unification of time dimensions is realized.

Description

Technical Field

[0001] The invention relates to a multi-optical field-of-view photoelectric system for high-precision navigation, and belongs to the technical field of positioning, navigation and control. Background Art

[0002] The roll angle accuracy of a star sensor is generally an order of magnitude lower than the pitch and yaw angle accuracy. From the perspective of attitude solution, the wider the spatial distribution of the observation vector, the higher the accuracy of the three-axis attitude solution. However, the star angle distance measured by a single-field-of-view star sensor will not be larger than its field of view. To overcome the shortcomings of single-field-of-view star sensors, multiple star sensors are usually installed on spacecraft to expand the observed sky area and improve the accuracy and reliability of attitude measurement.

[0003] As the number of star sensors increases, on the one hand, the overall weight and volume increase exponentially, and on the other hand, they are independent of each other, and the accuracy of their direction and time is difficult to guarantee. A new configuration must be adopted to achieve high-precision fusion and unification of the time and space dimensions of multi-field-of-view star sensors. Summary of the Invention

[0004] The technical problem solved by the present invention is that, in the current existing technology, conventional single-field-of-view star sensors have insufficient attitude measurement accuracy. Furthermore, after physically splicing multiple independent star sensors into a multi-field-of-view sensor system, the uncertainty in direction and time accuracy results in low measurement accuracy, and there is a lack of a photoelectric detection system that can achieve a high degree of integration and unification of time and space. Therefore, a multi-optical field-of-view photoelectric system for high-precision navigation is proposed.

[0005] The present invention solves the above technical problems by the following technical solutions:

[0006] A multi-optical field-of-view optoelectronic system for high-precision navigation:

[0007] It includes a coaxial primary mirror, a secondary reflector, a plane reflector, a lens group and a detector assembly, wherein:

[0008] The coaxial primary mirror is used to receive incident light from each field of view and reflect it to the secondary reflector; a reflected light through hole is provided in the middle of the coaxial primary mirror;

[0009] The secondary reflector gathers the incident light from each field of view reflected by the coaxial primary mirror to form reflected light, which is then directed to the plane reflector through the reflected light through-hole of the coaxial primary mirror;

[0010] A plane reflector deflects the reflected light from the secondary reflector and then injects it into the lens group;

[0011] A lens assembly receives the reflected light after the light beam is turned, processes the light path, and then inputs it into the detector assembly;

[0012] The detector assembly receives the incident light after optical path processing, and unifies the time dimension of each field of view according to the star map corresponding to the incident light in each field of view to achieve target detection in each field of view.

[0013] The coaxial primary mirror receives incident light from each field of view in two ways, including directly receiving the incident light from the field of view or receiving the incident light from each field of view through a folding reflector. The folding reflector is a plane reflector, and the number is set to two, which is used to collect incident light from the field of view in different vector directions to increase the observation range.

[0014] The coaxial primary mirror adopts an annular reflector, and the reflective surface of the annular reflector is provided with a coating area of ​​the same diameter, and each coating area is provided with a circular anti-reflection film. The coaxial primary mirror corresponds to the main reflector of each field of view through the anti-reflection film to achieve mutual non-interference and common incidence of the reflection areas of each field of view.

[0015] The gap condition of the edge distance △ of the circular anti-reflection film in each field reflection area is:

[0016] △≥0 and the angle θ between the center of each field reflection area and the center of the annular reflector, the radius r of the reflection area and the distance R between the center of each reflection area and the center of the annular reflector satisfy θ≥2arcsin(r / R).

[0017] The detector assembly receives all incident light in the field of view through the same area of ​​the photosensitive surface, and uses a CCD / CMOS module to unify the time dimension of each field of view according to the star map corresponding to the incident light; the field of view size in each vector direction is the same and the imaging area on the detector assembly is the same.

[0018] The detector assembly receives all incident light in the field of view and performs data fusion to filter out noise data. During the data fusion process, the detector assembly searches for abnormal data through self-checking and eliminates the abnormal data before outputting fused light.

[0019] The detector assembly performs a method for unifying the time dimensions of each field of view of the star map corresponding to the incident light as follows:

[0020] Select a vector direction as the target area, obtain the corresponding star map of the current field of view and perform matching processing;

[0021] Use the field of view areas in other vector directions as the field of view background and eliminate targets in the field of view areas in other vector directions;

[0022] After completing the target culling in the target area of ​​the current vector direction, replace the field of view area of ​​other vector directions as the target area, adjust the field of view background to the field of view area of ​​other vector directions, and after traversing the target areas of each vector direction, obtain a multi-vector field of view area that only includes the target to be extracted.

[0023] The coaxial primary mirror, secondary reflector, plane reflector, lens group and detector assembly are all arranged on a support assembly, and the support assembly includes a mirror base, a lens barrel and a support frame. The mirror base is used to install the coaxial primary mirror, secondary reflector and plane reflector; the lens barrel is used to install the lens group; and the support frame is used to provide auxiliary support for the detector assembly. The support assembly is made of materials whose expansion coefficient meets the requirements of optical path construction. The inner surfaces of the mirror base, lens barrel and support frame are all black anodized to reduce the interference of stray light energy.

[0024] The lens group includes a first lens, a second lens, a third lens, and a fourth lens, which are arranged in the order of the optical paths of the reflected light after the light beam is turned. The first lens, the second lens, the third lens, and the fourth lens are all meniscus lenses.

[0025] The angles between the main light rays in the incident direction in the fields of view of each vector direction are updated according to the optoelectronic requirements of the multi-optical field of view; the coaxial primary mirror realizes the off-axis catadioptric incidence form of the aperture through the reflective light through-hole to reduce center occlusion.

[0026] The advantages of the present invention compared with the prior art are:

[0027] (1) The present invention provides a high-precision navigation multi-optical field-of-view optoelectronic system, which adopts a multi-field-of-view common optical path configuration, uses a plane reflector to realize multiple fields of view with different vectors, and receives star maps collected from multiple fields of view with different vector directions through the same CCD / CMOS, thus achieving a high degree of integration and unification of time and space. In addition, the light beams received from multiple fields of view are passed through the common optical path, which simplifies the system volume and reduces the system quality.

[0028] (2) The present invention proposes a multi-field star sensor configuration, which designs multiple optical fields of view with different vector directions and uses a common optical path to image on the same CCD / CMOS. This method can, on the one hand, multiply the range of the observed sky area and improve the accuracy of the three-axis attitude solution; on the other hand, it can reduce the volume and mass of the optical-mechanical system, thus achieving miniaturization and lightweighting of the multi-field star sensor.

[0029] (3) The present invention designs multiple fields of view to be imaged on the photosensitive surface of the same detector, solving the problem that existing multi-field star sensors are simply physically spliced, which leads to uncertainty in direction and time accuracy and affects measurement accuracy, and realizes high-precision unification of multi-field star sensors in time and space dimensions;

[0030] (4) The optical systems of multiple fields of view in the present invention all adopt a catadioptric structure with off-axis aperture, which solves the center occlusion problem introduced by the coaxial catadioptric system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1Schematic diagram of the reflection areas corresponding to multiple different fields of view of the coaxial primary mirror provided by the invention;

[0032] Figure 2 A schematic diagram of the three-field-of-view optoelectronic system provided for the invention;

[0033] Figure 3 Schematic diagram of the positional relationship of the three field of view and zero field of view chief rays provided by the invention. DETAILED DESCRIPTION

[0034] A high-precision navigation multi-optical field optoelectronic system consists of multiple optical fields of view in different vector directions. It adopts a highly integrated design and shares a CCD / CMOS to control the vector directions of multiple heads. It also integrates multiple off-axis optical systems with a common optical axis. Ultimately, through the same rear optical path optical system, the optical information of multiple vector directions in the object space is converged on the same optical focal plane. By using multiple heads with different direction vectors to expand the imaging sky area, high-precision unification of the time dimension is achieved.

[0035] A multi-optical field-of-view optoelectronic system for high-precision navigation includes a coaxial primary mirror, a secondary reflector, a plane reflector, a lens group, and a detector assembly, wherein:

[0036] The coaxial primary mirror is used to receive incident light from each field of view and reflect it to the secondary reflector; a reflected light through hole is provided in the middle of the coaxial primary mirror;

[0037] The secondary reflector gathers the incident light from each field of view reflected by the coaxial primary mirror to form reflected light, which is then directed to the plane reflector through the reflected light through-hole of the coaxial primary mirror;

[0038] A plane reflector deflects the reflected light from the secondary reflector and then injects it into the lens group;

[0039] A lens assembly receives the reflected light after the light beam is turned, processes the light path, and then inputs it into the detector assembly;

[0040] The detector assembly receives the incident light after optical path processing, and unifies the time dimension of each field of view according to the star map corresponding to the incident light in each field of view to achieve target detection in each field of view.

[0041] The coaxial primary mirror receives incident light from each field of view in two ways, including directly receiving the incident light from the field of view or receiving the incident light from each field of view through a folding reflector. The folding reflector adopts a plane reflector, and the number is set to two, which is used to realize the collection of incident light from the field of view in different vector directions to expand the observation range.

[0042] The coaxial primary mirror adopts an annular reflector. The reflective surface of the annular reflector is provided with a coating area of ​​the same diameter, and each coating area is provided with a circular anti-reflection film. The coaxial primary mirror corresponds to the main reflector of each field of view through the anti-reflection film to achieve mutual non-interference and common incidence of the reflection areas of each field of view.

[0043] The clearance condition of the edge distance △ of the circular anti-reflection film in each field of view reflection area is:

[0044] △≥0 and the angle θ between the center of each field reflection area and the center of the annular reflector, the radius r of the reflection area and the distance R between the center of each reflection area and the center of the annular reflector satisfy θ≥2arcsin(r / R).

[0045] The detector assembly receives all incident light from the field of view through the same area of ​​the photosensitive surface. Using a CCD / CMOS module, the time dimension of each field of view is unified according to the star map corresponding to the incident light. The field of view size of each vector direction is the same and the imaging area on the detector assembly is the same.

[0046] The detector assembly unifies the time dimension of each field of view of the star map corresponding to the incident light as follows:

[0047] Select a vector direction as the target area, obtain the corresponding star map of the current field of view and perform matching processing;

[0048] Use the field of view areas in other vector directions as the field of view background and eliminate targets in the field of view areas in other vector directions;

[0049] After completing the target culling in the target area of ​​the current vector direction, replace the field of view area of ​​other vector directions as the target area, adjust the field of view background to the field of view area of ​​other vector directions, and after traversing the target areas of each vector direction, obtain a multi-vector field of view area that only includes the target to be extracted.

[0050] The coaxial primary mirror, secondary reflector, plane reflector, lens group and detector assembly are all arranged on the support assembly. The support assembly includes a mirror base, a lens barrel and a support frame. The mirror base is used to install the coaxial primary mirror, secondary reflector and plane reflector. The lens barrel is used to install the lens group. The support frame is used to provide auxiliary support for the detector assembly. The support components are all made of materials with expansion coefficients that meet the requirements of optical path construction. The inner surfaces of the mirror base, lens barrel and support frame are all black anodized to reduce interference from stray light energy.

[0051] The lens group includes a first lens, a second lens, a third lens, and a fourth lens, which are arranged in the order of the optical paths of the reflected light after the light beam is turned. The first lens, the second lens, the third lens, and the fourth lens are all meniscus lenses.

[0052] The angles of the main light rays in the incident direction are 90° between the fields of view in each vector direction; the coaxial primary mirror realizes the off-axis catadioptric incidence form through the reflective light through-hole to reduce the center obstruction.

[0053] The following is further described in conjunction with the accompanying drawings and preferred embodiments:

[0054] In the current embodiment, if Figure 1 As shown in the figure, multiple areas of the coaxial primary mirror coated with circular anti-reflection films are characterized to reflect light beams of multiple different vector directions into the common optical path system. Each reflection area does not interfere with each other, and the edge distance △ between the two reflection areas must meet the following requirements:

[0055] △≥0;

[0056] That is, the angle θ between the center of each reflection area and the center of the primary mirror, the radius r of the reflection area, and the distance R between the center of the reflection area and the center of the primary mirror must satisfy:

[0057] θ ≥ 2arcsin(r / R);

[0058] Example 1:

[0059] Take three fields of view, such as Figure 2 As shown, the optoelectronic system for high-precision navigation includes a catadioptric mirror assembly, a reflector assembly, a rear lens assembly, and a CCD / CMOS, arranged in sequence from front to back along the incident direction of light. The catadioptric mirror assembly includes a 45°-angled catadioptric mirror 2 and a 45°-angled catadioptric mirror 3. Light is reflected from the catadioptric mirror assembly into the reflector assembly, achieving orthogonal object fields of view.

[0060] The reflector group includes a coaxial primary reflector 1, a secondary reflector 4, and a plane reflector 5, which are arranged in sequence from front to back. The coaxial primary reflector 1 is a concave reflector with a through hole in the middle. The secondary reflector 4 is a convex reflector. The plane reflector 5 is a plane reflector. The reflective surfaces of the coaxial primary reflector 1 and the secondary reflector 4 are opposite to each other, and the reflective surface of the coaxial primary reflector 1 is provided with an aperture stop.

[0061] The rear lens group of the rear optical path includes a first lens 6, a second lens 7, a third lens 8, and a fourth lens 9 which are arranged in sequence backward. The first lens 6, the second lens 7, the third lens 8, and the fourth lens 9 are all meniscus lenses.

[0062] The incident light of field of view 1 is directly directed to the coaxial main reflector 1, and the incident light of field of view 2 and field of view 3 passes through their corresponding folding mirrors 2 and turning mirrors 3 respectively, and the light is turned 90 degrees and then directed to the coaxial main reflector 1. The light beams of the three fields of view are reflected by the coaxial main reflector 1 to the secondary reflector 4. The secondary reflector 4 reflects the light beams of the three fields of view to form reflected light. The reflected light passes through the through hole in the middle of the coaxial main reflector 1 and is directed to the plane reflector 5. The plane reflector folds the light beam 90 degrees to minimize the system volume and further reduce the system mass.

[0063] The incident light of the three fields of view is reflected by the plane reflector 5 and then sequentially passes through the first lens 6, the second lens 7, the third lens 8, and the fourth lens 9, and finally is emitted to the same area on the CCD / CMOS.

[0064] The direction of incident light is from front to back.

[0065] like Figure 3 As shown, Figure 3 The mutual angular relationship of the directions of the three fields of view is characterized. By making the angles of the three zero-field chief rays 90° to each other, the range of the observed sky area is expanded and the accuracy of the system is maximized.

[0066] Furthermore, compared to a single field of view, multiple fields of view can simultaneously capture the position information of more stars, improve the accuracy of attitude determination, reduce errors, and quickly capture the position changes of stars across a large range of sky areas, improving the system's response speed and real-time performance.

[0067] The detector component receives optical signals collected from multiple fields of view and performs multi-field data fusion. The system can more effectively filter noise and abnormal data, improving system accuracy, stability and reliability.

[0068] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions 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 solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

[0069] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A multi-optical field of view optoelectronic system for high-precision navigation, characterized by: It includes a coaxial primary mirror, a secondary reflector, a plane reflector, a lens group and a detector assembly, wherein: A coaxial primary mirror is used to receive incident light from each field of view and reflect it to a secondary reflector; The secondary reflector gathers the incident light from each field of view reflected by the coaxial primary mirror to form reflected light, which is then directed to the plane reflector through the reflected light through-hole provided in the middle of the coaxial primary mirror; A plane reflector deflects the reflected light from the secondary reflector and then injects it into the lens group; A lens assembly receives the reflected light after the light beam is turned, processes the light path, and then inputs it into the detector assembly; The detector assembly receives the incident light after optical path processing, and unifies the time dimension of each field of view according to the star map corresponding to the incident light in each field of view to achieve target detection in each field of view.

2. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 1, characterized in that: The coaxial primary mirror receives incident light from each field of view in two ways, including directly receiving the incident light from the field of view or receiving the incident light from each field of view through a folding reflector. The folding reflector is a plane reflector, and the number is set to two, which is used to collect incident light from the field of view in different vector directions to increase the observation range.

3. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 1, characterized in that: The coaxial primary mirror adopts an annular reflector, and the reflective surface of the annular reflector is provided with a coating area of ​​the same diameter, and each coating area is provided with a circular anti-reflection film. The coaxial primary mirror corresponds to the main reflector of each field of view through the anti-reflection film to achieve mutual non-interference and common incidence of the reflection areas of each field of view.

4. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 3, characterized in that: The gap condition of the edge distance △ of the circular anti-reflection film in each field reflection area is: △≥0 and the angle θ between the center of each field reflection area and the center of the annular reflector, the radius r of the reflection area and the distance R between the center of each reflection area and the center of the annular reflector satisfy θ≥2arcsin(r / R).

5. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 1, characterized in that: The detector assembly receives all incident light in the field of view through the same area of ​​the photosensitive surface, and uses a CCD / CMOS module to unify the time dimension of each field of view according to the star map corresponding to the incident light; the field of view size in each vector direction is the same and the imaging area on the detector assembly is the same.

6. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 5, characterized in that: The detector assembly receives all incident light in the field of view and performs data fusion to filter out noise data. During the data fusion process, the detector assembly searches for abnormal data through self-checking and eliminates the abnormal data before outputting fused light.

7. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 5, characterized in that: The detector assembly performs a method for unifying the time dimensions of each field of view of the star map corresponding to the incident light as follows: Select a vector direction as the target area, obtain the corresponding star map of the current field of view and perform matching processing; Use the field of view areas in other vector directions as the field of view background and eliminate targets in the field of view areas in other vector directions; After completing the target culling in the target area of ​​the current vector direction, replace the field of view area of ​​other vector directions as the target area, adjust the field of view background to the field of view area of ​​other vector directions, and after traversing the target areas of each vector direction, obtain a multi-vector field of view area that only includes the target to be extracted.

8. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 5, characterized in that: The coaxial primary mirror, secondary reflector, plane reflector, lens group and detector assembly are all arranged on a support assembly, and the support assembly includes a mirror base, a lens barrel and a support frame. The mirror base is used to install the coaxial primary mirror, secondary reflector and plane reflector; the lens barrel is used to install the lens group; and the support frame is used to provide auxiliary support for the detector assembly. The support assembly is made of materials whose expansion coefficient meets the requirements of optical path construction. The inner surfaces of the mirror base, lens barrel and support frame are all black anodized to reduce the interference of stray light energy.

9. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 1, characterized in that: The lens group includes a first lens, a second lens, a third lens, and a fourth lens, which are arranged in the order of the optical paths of the reflected light after the light beam is turned. The first lens, the second lens, the third lens, and the fourth lens are all meniscus lenses.

10. The multi-optical field of view optoelectronic system for high-precision navigation according to claim 1, characterized in that: The angles between the main light rays in the incident direction in the fields of view of each vector direction are updated according to the optoelectronic requirements of the multi-optical field of view; the coaxial primary mirror realizes the off-axis catadioptric incidence form of the aperture through the reflective light through-hole to reduce center occlusion.

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