Star sensor thermostat calibration device and star sensor calibration system

Abstract

The application discloses a star sensor constant-temperature calibration device and a star sensor calibration system, and the device comprises a rotary table adapter, a calibration base group and a shell group; the rotary table adapter is fixedly connected with a high-precision two-axis rotary table; the calibration base group is installed on the rotary table adapter and comprises a calibration base, a star sensor fixing seat for installing a star sensor and a base heat insulation pad arranged between the calibration base and the star sensor fixing seat; the shell group is combined with the calibration base group to form a heat insulation constant-temperature inner cavity for accommodating the star sensor, and the shell group comprises an inner container, an outer shell, a top cover, a top heat insulation pad arranged between the top of the inner container and the top cover, an inner container and outer shell heat insulation pad arranged between the inner container and the outer shell and an electric heating film arranged on the top of the inner container and the wall of the inner container; the heat insulation pads each comprise two layers of heat insulation materials arranged in a stack to reduce heat transfer between the heat insulation constant-temperature inner cavity and the external environment; and the electric heating film is used for heating the heat insulation constant-temperature inner cavity. The application can realize effective heat insulation function and ensure high-precision temperature constancy.

Description

Technical Field

[0001] This invention relates to the field of calibration fixtures, specifically to a constant temperature calibration device and a star sensor calibration system. Background Technology

[0002] Star sensors, using stars as observation references, output high-precision three-axis attitude and are core navigation equipment for spacecraft. Achieving high precision in star sensors requires error compensation during the calibration process. Star sensor calibration refers to determining the parameters of the star sensor's measurement model under specified conditions using specialized equipment, establishing the correspondence between the stellar observation vector and the coordinates of the stellar image point. The specialized laboratory calibration equipment typically includes: a single-star simulator (colour tube), a high-precision two-axis turntable, and a temperature control device. The temperature control device is primarily used for isothermal calibration of the star sensor, eliminating sub-arcsecond errors introduced by temperature gradients and thermal stress, establishing a temperature-error model, and compensating for thermal drift.

[0003] The temperature control device is installed on a two-axis turntable. The general-purpose temperature control box is heavy, which increases the load on the turntable and makes it more difficult to achieve high-precision rotational positioning. The calibration reference for the star sensor is a high-precision turntable, and the general-purpose temperature control box cannot guarantee the installation stability and repeatability requirements between the star sensor and the turntable. The star sensor that needs to be calibrated is installed inside the temperature control device. The star sensor needs to be aligned with the collimator, and the transparent window of the general-purpose temperature control box cannot guarantee the star point optical path transmission requirements of the collimator. Summary of the Invention

[0004] The main objective of this invention is to provide a constant temperature calibration device and system for a star sensor. By using a double-layer aerogel felt heat insulation pad and two layers of glass windows, the constant temperature calibration device can achieve effective heat insulation and ensure high-precision constant temperature.

[0005] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a constant temperature calibration device for a star sensor, the device comprising a turntable adapter, a calibration base assembly, and a housing assembly; The turntable adapter is fixedly connected to the high-precision two-axis turntable. The calibration base assembly is mounted on the turntable adapter. The calibration base assembly includes a calibration base, a star sensor mounting base for mounting a star sensor, and a base heat insulation pad disposed between the calibration base and the star sensor mounting base. The housing assembly and the calibration base assembly are combined to form a heat-insulated and temperature-controlled inner cavity for accommodating the star sensor. The housing assembly includes an inner liner, an outer shell surrounding the inner liner, a top cover covering the top of the inner liner, a top heat insulation pad disposed between the top of the inner liner and the top cover, an inner liner and outer shell heat insulation pad disposed between the inner liner and the outer shell, and an electric heating film disposed on the top of the inner liner and the inner liner wall. The base heat insulation pad, the top heat insulation pad, and the inner liner and outer shell heat insulation pad all include two layers of heat insulation material stacked together to reduce heat transfer between the heat-insulated constant temperature inner cavity and the external environment; the electric heating film is used to heat the heat-insulated constant temperature inner cavity.

[0006] Furthermore, the base heat insulation pad, the top heat insulation pad, and the inner liner and outer shell heat insulation pad are all double-layer type IIA aerogel felt.

[0007] Furthermore, the exposed portion of the base heat insulation pad is fixed by a heat insulation pad pressure plate.

[0008] Furthermore, the heating film includes an inner liner top heating film disposed on the top of the inner liner and an inner liner wall heating film disposed on the inner liner wall. The inner liner top heating film and the inner liner wall heating film are respectively fixed to the inner liner by corresponding heating film pressure plates.

[0009] Furthermore, both the inner liner top heating film and the inner liner wall heating film are polyimide heating films.

[0010] Furthermore, the housing assembly also includes a glass tube, double-layered window glass disposed within the glass tube, a glass spacer disposed between the two layers of window glass, and a glass pressure ring for fixing the window glass; the glass tube is fixed to the outer shell.

[0011] Furthermore, the calibration base is provided with a positioning pin, a mounting boss, and a mounting screw hole. The bottom of the star sensor mounting base is provided with a positioning pin hole that mates with the positioning pin and a mounting fixing through hole that corresponds to the mounting screw hole. The positioning pin is inserted into the positioning pin hole to position the star sensor mounting base. The star sensor mounting base is supported on the mounting boss. Fasteners pass through the mounting fixing through hole and mate with the mounting screw hole to fix the star sensor mounting base to the calibration base.

[0012] Furthermore, the inner liner and the outer shell are connected by a heat-insulating connecting post, which is made of polyetheretherketone material.

[0013] Furthermore, both the calibration base and the star sensor mounting base are made of a low-expansion iron-nickel-cobalt alloy.

[0014] In a second aspect, the present invention provides a star sensor calibration system, including a single-star simulator, a high-precision two-axis turntable, and the star sensor constant-temperature calibration device described in the first aspect; the star sensor constant-temperature calibration device is installed on the high-precision two-axis turntable, the star sensor is placed in the heat-insulated constant-temperature inner cavity of the star sensor constant-temperature calibration device, and the single-star simulator is arranged opposite to the star sensor.

[0015] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: This invention mounts the constant temperature calibration device onto a high-precision two-axis turntable via a turntable adapter, and positions and fixes the star sensor using a calibration base assembly. This reduces the additional load on the turntable and improves the installation stability and repeatability of the star sensor. The calibration base and the star sensor mounting base are made of low-expansion materials and are fitted together by positioning pins, mounting bosses, and base heat insulation pads. This ensures positioning and connection while reducing heat transfer between the two components, thus reducing thermal deformation caused by temperature changes. The inner liner, outer shell, top cover, double-layer aerogel felt heat insulation pad, double-layer glass window, and heating film together form a thermal insulation and constant temperature structure, which helps reduce heat loss and improves the uniformity of heating within the cavity, thereby enhancing the reliability and accuracy of the star sensor's constant temperature calibration. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating the composition of a star sensor laboratory calibration system according to an embodiment of the present invention. Figure 2 This is a diagram illustrating the composition of a star sensor constant temperature calibration device according to an embodiment of the present invention. Figure 3 This is a diagram showing the assembly of the calibration base of a star sensor constant temperature calibration device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the housing assembly of a star sensor constant temperature calibration device according to an embodiment of the present invention.

[0017] In the diagram: 1-1, Star sensor constant temperature calibration device; 1-2, High-precision two-axis turntable; 1-3, Single-star simulator; 2-1, Housing assembly; 2-2, Calibration base assembly; 2-3, Turntable adapter; 2-4, Housing assembly fixing screws; 2-5, Adapter fixing screws; 3-1, Calibration base; 3-2, Base heat insulation pad; 3-3, Star sensor mounting screws; 3-4, Star sensor mounting base; 3-5, Positioning pin; 3-6, Star sensor; 3-7, Star sensor fixing screws; 3-8, Heat insulation pad fixing screws; 3-9, Heat insulation pad pressure... 4-1. Inner liner; 4-2. Inner liner top heating film; 4-3. Inner liner wall heating film; 4-4. Inner liner top heating film pressure plate; 4-5. Inner liner wall heating film pressure plate; 4-6. Top heat insulation pad; 4-7. Top cover; 4-8. Outer shell fixing screws; 4-9. Heat insulation connecting column; 4-10. Annular pressure plate fixing screws; 4-11. Inner liner and outer shell heat insulation pads; 4-12. Outer shell; 4-13. Glass tube; 4-14. Window glass; 4-15. Glass pressure ring; 4-16. Glass spacer ring; 4-17. Protective glass tube screws. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0019] Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0020] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention may be combined with other embodiments without conflict.

[0021] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," "an," "the," and similar words used in this invention do not indicate quantity limitation and may indicate singular or plural. The terms "comprising," "including," "having," and any variations thereof used in this invention are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms "connected," "linked," "coupled," and similar words used in this invention are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "A plurality" used in this invention refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships may exist; for example, "A and / or B" can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects have an "or" relationship. The terms "first," "second," and "third" used in this invention are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0022] This invention provides a constant-temperature calibration device for star sensors, applied in a star sensor laboratory calibration system. The star sensor to be calibrated is installed inside the constant-temperature calibration device to achieve high-precision error calibration of the star sensor under a constant ambient temperature. The constant-temperature calibration device is small in size and lightweight, with minimal load added to the turntable, and ensures the turntable's rotational accuracy. The constant-temperature calibration device guarantees the installation stability and repeatability of the star sensor and turntable, achieving high-precision error calibration. Double-layer aerogel felt and double-layer glass windows provide effective heat insulation, ensuring a high-precision constant temperature.

[0023] like Figure 1 As shown, the star sensor laboratory calibration system includes: a single star simulator (parallel light tube) 1-3, a high-precision two-axis turntable 1-2, and a star sensor constant temperature calibration device 1-1.

[0024] The star sensor constant temperature calibration device 1-1 is installed on the high-precision two-axis turntable 1-2. The star sensor is installed inside the star sensor constant temperature calibration device 1-1, which provides the specific constant temperature environment required for star sensor calibration.

[0025] The star sensor laboratory calibration system establishes a star sensor measurement model based on the star sensor imaging process. Using a single-star simulator and a high-precision two-axis turntable, it acquires calibration point and test point data in a prescribed manner, and substitutes the calibration point data into the measurement model to optimize and solve for the star sensor model parameters.

[0026] like Figure 2 As shown, the star sensor constant temperature calibration device includes: a turntable adapter 2-3, a calibration base assembly 2-2, and a housing assembly 2-1. The turntable adapter 2-3 is fixed to the high-precision two-axis turntable 1-2 by adapter fixing screws 2-5. The calibration base assembly 2-2 is installed on the turntable adapter 2-3. The calibration base assembly 2-2 is combined with the housing assembly 2-1 by the housing assembly fixing screws 2-4 to form a star sensor calibration heat-insulating constant temperature inner cavity. The housing assembly fixing screws 2-4 are GB / T839 knurled head non-removable screws, which are installed on the housing and do not come out, to prevent the screws from being lost when the housing assembly is removed. The knurled head can be tightened directly by hand, facilitating the quick installation of the housing assembly.

[0027] like Figure 3 As shown, the calibration base group 2-2 mainly includes: calibration base 3-1, base heat insulation pad 3-2, star sensor fixing base 3-4, and star sensor 3-6 to be calibrated.

[0028] The calibration base 3-1 has two locating pins 3-5, four mounting bosses, and mounting screw holes machined in the middle. The star sensor mounting bracket 3-4 has locating pin holes and mounting through holes machined at the bottom corresponding to the calibration base, allowing for quick installation of the star sensor mounting bracket 3-4 onto the calibration base 3-1 and tightening with the star sensor mounting bracket mounting screws 3-3. Only the locating pins and mounting bosses have a small contact area between the calibration base 3-1 and the star sensor mounting bracket 3-4, reducing the area for heat conduction between the two parts.

[0029] A base heat insulation pad 3-2 is laid between the calibration base 3-1 and the star sensor mounting base 3-4 to block heat radiation between the two parts; the exposed base heat insulation pad 3-2 is fixed by heat insulation pad fixing screws 3-8 and heat insulation pad pressure plate 3-9 to prevent the heat insulation pad from warping and deforming.

[0030] The star sensor 3-6 is mounted on the star sensor mounting base 3-4 by the star sensor fixing screw 3-7. The star sensor mounting base 3-4 is machined with reinforcing ribs to enhance the rigidity of the parts and ensure that there is little thermal deformation between the mounting surface of the star sensor mounting base and the mounting surface of the star sensor when the temperature changes.

[0031] The base heat insulation pad uses double-layer type IIA aerogel felt. The thermal conductivity of the aerogel felt is ≤0.021W / (mK) at an average temperature of 25℃ and ≤0.036 W / (mK) at an average temperature of 300℃. The classification temperature is 450℃ and the long-term operating temperature is 300℃~400℃, which meets the high-temperature heat insulation requirements of the star sensor constant temperature calibration device.

[0032] The calibration base 3-1 is designed with a positioning pin, and the housing assembly 2-1 can be quickly positioned and installed using the positioning pin.

[0033] like Figure 4 As shown, the shell assembly 2-1 mainly includes: inner liner 4-1; outer shell 4-12; top cover 4-7; inner liner top heating film 4-2; inner liner wall heating film 4-3; inner liner top heating film pressure plate 4-4; inner liner wall heating film pressure plate 4-5; top heat insulation pad 4-6; inner liner and outer shell heat insulation pad 4-11; heat insulation connecting column 4-9; glass tube 4-13; window glass 4-14; glass spacer 4-16; glass pressure ring 4-15.

[0034] The inner liner 4-1 and the outer shell 4-12 are connected by a heat-insulating connecting post 4-9. The outer shell 4-12 and the top cover 4-7 are fastened to the inner liner 4-1 by outer shell fixing screws 4-8. A heat insulation pad 4-11 is laid between the inner liner 4-1 and the outer shell 4-12, and a top heat insulation pad 4-6 is laid on top of the inner liner 4-1.

[0035] The inner liner and outer shell heat insulation pad 4-11 and the top heat insulation pad 4-6 are both made of double-layer type IIA aerogel felt.

[0036] The top of the inner liner 4-1 and the inner liner wall are covered with an inner liner top electric heating film 4-2; the inner liner wall electric heating film 4-3 and the outer side of the electric heating film are respectively fixed by an inner liner top electric heating film pressure plate 4-4 and an inner liner wall electric heating film pressure plate 4-5, and the above pressure plates are fastened by annular pressure plate fixing screws 4-10.

[0037] The heating film is made of polyimide, which heats up quickly, has high temperature control accuracy, and provides uniform surface heating without localized high temperatures. An inner liner top / wall heating film pressure plate is fitted around the heating film to ensure a close fit and prevent peeling or detachment over long-term use. The heating film heats up evenly through heat conduction within the inner liner and then radiates evenly into the inner cavity, achieving uniform heating of the inner liner cavity.

[0038] The housing assembly 2-1 is equipped with double-glazed windows 4-14, which are installed inside the window glass tube 4-13 and fixed with glass retaining rings 4-15. The double-glazed windows 4-14 are separated by glass spacers 4-16. The glass tube 4-13 is fixed to the outer casing 4-12 by protective glass tube screws 4-17.

[0039] The window glass is made of K9 material, 6mm thick, with a parallelism difference of ≤3″, and coated with an anti-reflective film. The window glass is installed inside the window glass barrel and fixed with a glass retainer. The double-glazed windows are separated by a glass spacer, which provides thermal insulation. The window glass barrel, glass spacer, and glass retainer are all made of PEEK material.

[0040] In addition, the present invention also provides a star sensor calibration system, including a single-star simulator, a high-precision two-axis turntable, and the aforementioned star sensor constant temperature calibration device; the star sensor constant temperature calibration device is installed on the high-precision two-axis turntable, the star sensor is placed in the heat-insulated constant temperature inner cavity of the star sensor constant temperature calibration device, and the single-star simulator is arranged opposite to the star sensor.

[0041] It should be noted that, depending on the implementation needs, the various steps / components described in this invention can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0042] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A constant-temperature calibration device for a star sensor, characterized in that, The device includes a turntable adapter, a calibration base assembly, and a housing assembly; The turntable adapter is fixedly connected to the high-precision two-axis turntable. The calibration base assembly is mounted on the turntable adapter. The calibration base assembly includes a calibration base, a star sensor mounting base for mounting a star sensor, and a base heat insulation pad disposed between the calibration base and the star sensor mounting base. The housing assembly and the calibration base assembly are combined to form a heat-insulated and temperature-controlled inner cavity for accommodating the star sensor. The housing assembly includes an inner liner, an outer shell surrounding the inner liner, a top cover covering the top of the inner liner, a top heat insulation pad disposed between the top of the inner liner and the top cover, an inner liner and outer shell heat insulation pad disposed between the inner liner and the outer shell, and an electric heating film disposed on the top of the inner liner and the inner liner wall. The base heat insulation pad, the top heat insulation pad, and the inner liner and outer shell heat insulation pad all include two layers of heat insulation material stacked together to reduce heat transfer between the heat-insulated constant temperature inner cavity and the external environment; the electric heating film is used to heat the heat-insulated constant temperature inner cavity.

2. The star sensor constant temperature calibration device according to claim 1, characterized in that, The base heat insulation pad, the top heat insulation pad, and the inner liner and outer shell heat insulation pad are all double-layer type IIA aerogel felt.

3. The star sensor constant temperature calibration device according to claim 1, characterized in that, The exposed portion of the base heat insulation pad is fixed by the heat insulation pad pressure plate.

4. The star sensor constant temperature calibration device according to claim 1, characterized in that, The heating film includes an inner liner top heating film disposed on the top of the inner liner and an inner liner wall heating film disposed on the inner liner wall. The inner liner top heating film and the inner liner wall heating film are respectively fixed to the inner liner by corresponding heating film pressure plates.

5. The star sensor constant temperature calibration device according to claim 4, characterized in that, Both the inner liner top heating film and the inner liner wall heating film are polyimide heating films.

6. The star sensor constant temperature calibration device according to claim 1, characterized in that, The housing assembly further includes a glass tube, double-layered window glass disposed within the glass tube, a glass spacer disposed between the two layers of window glass, and a glass pressure ring for fixing the window glass; the glass tube is fixed to the outer shell.

7. The star sensor constant temperature calibration device according to claim 1, characterized in that, The calibration base is provided with a positioning pin, a mounting boss, and a mounting screw hole. The bottom of the star sensor mounting base is provided with a positioning pin hole that mates with the positioning pin and a mounting fixing through hole that corresponds to the mounting screw hole. The positioning pin is inserted into the positioning pin hole to position the star sensor mounting base. The star sensor mounting base is supported on the mounting boss. Fasteners pass through the mounting fixing through hole and mate with the mounting screw hole to fix the star sensor mounting base to the calibration base.

8. The star sensor constant temperature calibration device according to claim 1, characterized in that, The inner liner and the outer shell are connected by a heat-insulating connecting column, which is made of polyetheretherketone material.

9. The star sensor constant temperature calibration device according to claim 1, characterized in that, Both the calibration base and the star sensor mounting base are made of low-expansion iron-nickel-cobalt alloy.

10. A star sensor calibration system, characterized in that, The device includes a single-star simulator, a high-precision two-axis turntable, and a star sensor constant-temperature calibration device as described in any one of claims 1 to 9; the star sensor constant-temperature calibration device is installed on the high-precision two-axis turntable, the star sensor mounting base is located in the heat-insulated constant-temperature inner cavity, the star sensor is installed on the star sensor mounting base, and the single-star simulator is arranged opposite to the star sensor.

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