A device and system for on-site calibration of geometric parameters of starlight simulator

Abstract

The present invention discloses a device and system for on-site calibration of geometric parameters of a starlight simulator, the device comprising an optical element, a translation mechanism, an image acquisition device and a data processing device; the optical element is mounted on the translation mechanism, and the image acquisition device is mounted on one end of the translation mechanism; the optical element is used to deflect the emergent light of the starlight simulator to be calibrated, the translation mechanism is used to drive the optical element and the image acquisition device to translate, during the translation process the image acquisition device is used to collect a starlight image formed after the emergent light is deflected by the optical element and send it to the data processing device, the data processing device is used to calculate the parallelism of the starlight simulator to be calibrated according to the starlight image; the device does not need to use a collimator, avoids human eye alignment and reading errors, and improves the accuracy and reliability of parallelism calibration of the starlight simulator.

Description

Technical Field

[0001] The present invention relates to the field of optical testing technology, and in particular to a device and system for on-site calibration of geometric parameters of a starlight simulator. Background Art

[0002] The use of starlight for positioning and navigation by spacecraft is a new method for autonomous navigation of spacecraft. It does not rely on navigation methods such as radio and GPS, and has very important applications in deep space exploration and orbiting the earth by spacecraft. Therefore, in-depth research on astronomical navigation technology is being conducted both at home and abroad. However, experimental research on the use of astronomical positioning and navigation technology by spacecraft is not only difficult but also expensive, so ground-based semi-physical simulation is used for experimental research both at home and abroad. Using the semi-physical simulation experimental system for spacecraft astronomical navigation, we can conduct in-depth research on the key positioning and navigation technologies of spacecraft, accurately simulate measurement information and its error characteristics, and thus accurately verify the effectiveness and accuracy of astronomical navigation methods and conduct system accuracy analysis.

[0003] As a ground parameter correction and function detection device for star sensors, starlight simulators have a great influence on the positioning accuracy of star sensors. Therefore, the adjustment of starlight simulators is a very important task. Since stars can be regarded as point light sources at infinity, when star sensors are actually working, they will treat starlight as parallel light, so the output light of the starlight simulator must be parallel light. In practice, starlight simulators generally generate parallel light by placing point light sources on the focal plane of a parallel light tube. Due to the existence of various errors, the parallelism error of the parallel light generated directly in this way is large, so the starlight simulator needs to be calibrated so that the parallelism of its output light can meet the requirements of the ground test of the star sensor.

[0004] The conventional method for calibrating the parallelism of a starlight simulator is to use optical elements and optical autocollimators for calibration. The light emitted by a single star light source passes through the optical system to form parallel light with a certain field angle. The optical element is placed on a one-dimensional guide rail and translated from one side of the light outlet of the starlight simulator to the other side. In this process, the emitted parallel light is turned 90° and enters the optical autocollimator. The human eye cooperates with the autocollimator graticule to read the moving angle difference of a single star light point during the movement of the pentaprism, which is recorded as the parallelism value. However, this method has the problems of weak energy of a single star light source, errors in human eye alignment and reading, and errors in the autocollimator's own calibration. The measurement uncertainty value is relatively large. For a high-precision starlight simulator, this measurement uncertainty value can no longer meet the requirements of design and simulation. In addition, this method is complex to operate and has high requirements for the calibration site. Summary of the invention

[0005] The present invention provides a device and system for on-site calibration of geometric parameters of a starlight simulator, so as to solve the problems of large error and low precision in calibration of starlight simulator in the prior art.

[0006] A device for calibrating geometric parameters of a starlight simulator on site, comprising an optical element, a translation mechanism, an image acquisition device and a data processing device;

[0007] The optical element is mounted on the translation mechanism, and the image acquisition device is mounted on one end of the translation mechanism;

[0008] The optical element is used to fold the outgoing light of the starlight simulator to be calibrated, and the translation mechanism is used to drive the optical element and the image acquisition device to translate. During the translation process, the image acquisition device is used to collect the starlight image formed after the outgoing light is folded by the optical element and send it to the data processing device. The data processing device is used to calculate the parallelism of the starlight simulator to be calibrated based on the starlight image.

[0009] Furthermore, the optical element is a pentaprism.

[0010] Furthermore, the image acquisition device is a CCD camera.

[0011] Furthermore, the travel of the translation mechanism is 300 mm, and the straightness is 0.01 mm to 300 mm.

[0012] Furthermore, the data processing device is an industrial control computer.

[0013] Furthermore, the calibration device also includes an optical platform, and the translation mechanism is arranged on the optical platform.

[0014] Furthermore, the parallelism of the starlight simulator to be calibrated is calculated by the following formula:

[0015] α=|n1-n2|×α0;

[0016] Among them, n1 is the pixel coordinate of the center of the star point image quality at one end of the starlight simulator to be calibrated; n2 is the pixel coordinate of the center of the star point image quality at the other end of the starlight simulator to be calibrated; α0 is the angle corresponding to a single pixel of the starlight simulator to be calibrated, and α is the parallelism of the starlight simulator to be calibrated.

[0017] A starlight simulator geometric parameter on-site calibration system comprises the above-mentioned starlight simulator geometric parameter on-site calibration device and a starlight simulator to be calibrated.

[0018] The on-site calibration device and system for geometric parameters of a starlight simulator provided by the present invention have at least the following beneficial effects:

[0019] (1) No need to use a collimator, avoiding human eye alignment and reading errors, and improving the accuracy and reliability of the parallelism calibration of the starlight simulator;

[0020] (2) It can be applied to high-precision starlight simulators and can provide the parallelism values ​​of the starlight simulator in the horizontal and vertical directions, providing real-time and accurate geometric optical information for the installation and adjustment of the starlight simulator, thereby ensuring the collimation of the output light of the starlight simulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of an embodiment of a field calibration system for geometric parameters of a starlight simulator provided by the present invention. Specific implementation plan

[0022] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] refer to Figure 1 , in some embodiments, a starlight simulator geometric parameter field calibration device is provided, comprising an optical element 1, a translation mechanism 2, an image acquisition device 3 and a data processing device 4;

[0024] The optical element 1 is mounted on the translation mechanism 2, and the image acquisition device 3 is mounted on one end of the translation mechanism 2;

[0025] The optical element 1 is used to fold the outgoing light of the starlight simulator 10 to be calibrated, and the translation mechanism 2 is used to drive the optical element 1 and the image acquisition device 3 to translate. During the translation process, the image acquisition device 3 is used to collect the starlight image formed after the outgoing light is folded by the optical element 1 and send it to the data processing device 4. The data processing device 4 is used to calculate the parallelism of the starlight simulator 10 to be calibrated based on the starlight image.

[0026] In some embodiments, the optical element 1 is a pentaprism, and the pentaprism can be an Edmont 25mm×25mm standard aperture pentaprism, and the folded optical axis accuracy is 0.1″.

[0027] The pentaprism is a double-reflection prism. After reflection through the pentaprism, the imaging coordinate system of the starlight simulator remains unchanged, without mirror image and inverted image. Only the optical axis is bent 90° and emitted from the light outlet. In conjunction with the translation mechanism, push-scanning sampling at the light outlet of the starlight simulator can be realized.

[0028] In some embodiments, the image acquisition device 3 is a CCD camera, and the working band is the visible light band. The CCD camera can be specifically a 4-megapixel CCD industrial array camera from HIK, with a lens focal length of 15 mm and an effective resolution of 1980×1980.

[0029] In some embodiments, the translation mechanism 2 is a Jiangyun Optoelectronics high-precision one-dimensional translation mechanism with a stroke of 300 mm and a straightness of 0.01 mm to 300 mm, which can achieve translation in both horizontal and vertical directions.

[0030] In some embodiments, the data processing device 4 is an industrial computer.

[0031] In some embodiments, the calibration device further includes an optical platform 5 , and the translation mechanism 2 and the data processing device 4 are disposed on the optical platform 5 .

[0032] In some embodiments, the calibration device works as follows:

[0033] The starlight simulator 10 to be calibrated simulates a starlight source, and the brightness is adjusted to the maximum value. The light outlet of the starlight simulator 10 to be calibrated is aligned with the optical element 1, and the lens of the image acquisition device 3 is aligned with the optical element 1. The data processing device 4 controls the translation mechanism 2 to perform horizontal and vertical push-scanning. During the push-scanning process, the outgoing light of the starlight simulator 10 to be calibrated is folded 90° by the optical element 1 to form a starlight image. The image acquisition device 3 collects the starlight image and sends it to the data processing device 4. The data processing device calculates the parallelism of the starlight simulator 10 to be calibrated based on the starlight image. The parallelism of the starlight simulator to be calibrated is calculated by the following formula:

[0034] α=|n1-n2|×α0;

[0035] Among them, n1 is the pixel coordinate of the center of the star point image quality at one end of the starlight simulator to be calibrated; n2 is the pixel coordinate of the center of the star point image quality at the other end of the starlight simulator to be calibrated; α0 is the angle corresponding to a single pixel of the starlight simulator to be calibrated, and α is the parallelism of the starlight simulator to be calibrated.

[0036] In some embodiments, a starlight simulator geometric parameter field calibration system is also provided, including the above-mentioned starlight simulator geometric parameter field calibration device, and also includes a starlight simulator 10 to be calibrated.

[0037] In some embodiments, the starlight simulator geometric parameter field calibration device and system provided include at least the following beneficial effects:

[0038] (1) No need to use a collimator, avoiding human eye alignment and reading errors, and improving the accuracy and reliability of the parallelism calibration of the starlight simulator;

[0039] (2) It can be applied to high-precision starlight simulators and can provide the parallelism values ​​of the starlight simulator in the horizontal and vertical directions, providing real-time and accurate geometric optical information for the installation and adjustment of the starlight simulator, thereby ensuring the collimation of the output light of the starlight simulator.

[0040] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A device for calibrating the geometric parameters of a starlight simulator on site, characterized in that: It includes optical elements, translation mechanism, image acquisition device and data processing device; The optical element is mounted on the translation mechanism, and the image acquisition device is mounted on one end of the translation mechanism; The optical element is used to fold the outgoing light of the starlight simulator to be calibrated, the translation mechanism is used to drive the optical element and the image acquisition device to translate, during the translation process, the image acquisition device is used to collect the starlight image formed after the outgoing light is folded by the optical element and send it to the data processing device, and the data processing device is used to calculate the parallelism of the starlight simulator to be calibrated according to the starlight image; The parallelism of the starlight simulator to be calibrated is calculated by the following formula: α=|n1-n2|×α0; Among them, n1 is the pixel coordinate of the center of the star point image quality at one end of the starlight simulator to be calibrated; n2 is the pixel coordinate of the center of the star point image quality at the other end of the starlight simulator to be calibrated; α0 is the angle corresponding to a single pixel of the starlight simulator to be calibrated, and α is the parallelism of the starlight simulator to be calibrated.

2. The on-site calibration device for geometric parameters of a starlight simulator according to claim 1, characterized in that: The optical element is a pentaprism.

3. The on-site calibration device for geometric parameters of a starlight simulator according to claim 1, characterized in that: The image acquisition device is a CCD camera.

4. The on-site calibration device for geometric parameters of a starlight simulator according to claim 1, characterized in that: The travel of the translation mechanism is 300 mm, and the straightness is 0.01 mm to 300 mm.

5. The on-site calibration device for geometric parameters of a starlight simulator according to claim 1, characterized in that: The data processing device is an industrial control computer.

6. The on-site calibration device for geometric parameters of a starlight simulator according to claim 1, characterized in that: The calibration device also includes an optical platform, and the translation mechanism is arranged on the optical platform.

7. A starlight simulator geometric parameter field calibration system, characterized in that: It comprises the on-site calibration device for geometric parameters of a starlight simulator as described in any one of claims 1-6, and also comprises a starlight simulator to be calibrated.

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