A mounting structure and mounting method for a posture sensor

Abstract

This invention discloses a mounting structure suitable for an attitude sensor, comprising a support, a lens barrel, and a mounting enclosure. The support includes a housing, within which are provided a grating connection surface, an optical lens mounting surface, an optical lens mating surface, a printed circuit board mounting surface, and an external mounting surface. The grating of the attitude sensor is fixed within the housing via the grating connection surface. The optical lens of the attitude sensor is mounted within the lens barrel, which is fixed within the housing via the optical lens mounting surface and the optical lens mating surface. The electronic unit of the attitude sensor is mounted within the mounting enclosure, which is mounted on the housing via the printed circuit board mounting surface. The housing is mounted on a spacecraft via the external mounting surface. This invention also provides a method for mounting an attitude sensor. This invention ensures the stability and reliability of the attitude sensor and its electronic unit under conditions of large vibration, strong impact, and wide temperature variations, meeting the environmental and operational requirements of the attitude sensor.

Description

Technical Field

[0001] This invention relates to an installation structure, specifically to an installation structure and method suitable for attitude sensors. Background Technology

[0002] Attitude sensors are one of the fundamental components for spacecraft attitude measurement, and their reliability plays a crucial role in spacecraft attitude control. Many attitude sensors are independently mounted on the spacecraft without external buffers or vibration damping devices. Because they are directly fixed to the spacecraft, attitude sensors are directly subjected to high-frequency random vibrations (total root mean square may reach 18.5g) and high-frequency shocks (shock response spectrum may reach or exceed 8000g) from the spacecraft's launch boost phase.

[0003] Sometimes, attitude sensors require components with high power consumption and large size. During use, these components generate heat. Uneven heat dissipation can cause localized deformation of the attitude sensor, affecting measurement accuracy. Furthermore, the transition flow region behind the spacecraft's jettison fairing experiences significant heat flux. Free molecular flow, infrared radiation heat flux, and albedo heat flux during flight all contribute to temperature variations in the attitude sensor, creating a harsh thermal environment.

[0004] Attitude sensors mainly consist of an extinction grating, optical lenses, electronic units, and structural components. Among these, the electronic units are particularly sensitive to strong impacts, large vibrations, and thermal environments, and are more prone to damage and malfunction. In harsh space environments, attitude sensors, especially the electronic units, require robust mechanical and thermal design. Summary of the Invention

[0005] The main objective of this invention is to provide an installation structure and method suitable for attitude sensors. This structure and method can ensure the stability and reliability of the attitude sensor and its electronic unit head under conditions of large vibration, strong impact and wide temperature variation, thus meeting the usage environment and requirements of the attitude sensor.

[0006] The technical solution adopted in this invention is:

[0007] A mounting structure suitable for an attitude sensor includes a support, a lens barrel, and a sealing reinforcement box;

[0008] The support includes a housing, within which are provided an anti-glare grating connecting surface, an optical lens fixing surface, an optical lens mating surface, a printed circuit board fixing surface, and an external mounting surface. The anti-glare grating of the attitude sensor is fixed inside the housing via the anti-glare grating connecting surface. The optical lens of the attitude sensor is installed inside the lens barrel via the optical lens mating surface and the lens barrel mating surface, and the lens barrel is fixed inside the housing via the optical lens fixing surface and the optical lens mating surface. The electronic unit of the attitude sensor is installed inside a packaging reinforcement box, which is mounted on the housing via the printed circuit board fixing surface. The housing is mounted on the spacecraft via the external mounting surface.

[0009] Preferably, the electronic unit includes a printed circuit board and components located on the printed circuit board; each printed circuit board corresponds to a packaging reinforcement box (a corresponding packaging reinforcement box is designed according to the shape and size of each printed circuit board);

[0010] The reinforced enclosure includes a housing, a first thermal pad, and a printed circuit board (PCB) mounting surface on the housing. The first thermal pad is placed inside the housing and below the PCB, transferring heat from the components on the PCB to the housing. The housing is mounted on the PCB mounting surface of the housing. During installation, the first thermal pad is first adhered to the PCB components. Then, both are placed into the housing, and the PCB with the first thermal pad is secured to the housing using screws with flat washers and spring washers, making the three components a single unit. Finally, all three are mounted onto the PCB mounting surface of the support, completing the reinforced enclosure of the PCB. This structure greatly improves the rigidity of the PCB, providing excellent protection for components and their soldered leads under conditions of high vibration and strong impact.

[0011] Preferably, a second thermal pad is provided between the housing and the casing to transfer heat from the printed circuit board components to the casing, and then guide it along the casing to the attitude sensor mounting platform, effectively ensuring the thermal balance inside the attitude sensor. Simulation and actual testing showed that the temperature rise of the 12W attitude sensor did not exceed 10°C.

[0012] Preferably, to reduce the impact of high-frequency shocks on the attitude sensor, especially the printed circuit board components, a reinforced enclosure housing containing the printed circuit board is installed before the printed circuit board is secured to the support. A transition piece is added between the two (the enclosure is connected to the housing via the transition piece), and the enclosure is secured with screws equipped with flat washers and spring washers. When the attitude sensor is subjected to a high-frequency shock, the transition piece will partially attenuate the magnitude of the high-frequency shock, ultimately protecting the printed circuit board components.

[0013] Preferably, the compression of the first thermal pad is 10% to 15%, that is, the depth of the reinforced inner cavity is the height of the printed circuit board components plus 85% to 90% of the thermal pad thickness; thus enhancing the thermodynamic resistance of the printed circuit board.

[0014] Preferably, the thickness of the printed circuit board is not less than 2 mm; the flatness of the fixed surface and the mounting surface of the printed circuit board is not greater than 0.04 mm. The above structure can improve the deformation resistance of the printed circuit board and reduce the internal stress when the printed circuit board is installed and fixed, thereby reducing the stress on the solder feet of the soldering devices on the printed circuit board.

[0015] Preferably, the first-order mode of the support is higher than the highest vibration frequency of the attitude sensor, ensuring that the support does not generate resonance points across the entire frequency range. The support is the final load-bearing unit for all components in the attitude sensor, including the extinction grating, optical lens, and electronic units. Typically, the minimum natural frequency of the support is above 2000Hz. If the vibration frequency range of the attitude sensor is less than 2000Hz, the first-order mode of the support can be correspondingly reduced, ensuring that the first-order mode of the support is higher than the highest vibration frequency of the attitude sensor. This invention effectively reduces the vibration displacement and acceleration at the load-bearing positions of the internal components, ensuring the stability and reliability of the attitude sensor under conditions of large vibrations, strong impacts, and wide temperature variations, thus meeting usage requirements.

[0016] Preferably, the lens barrel is provided with a lens barrel mating surface and an optical lens mating surface; the diameter of the lens barrel mating surface adopts G7 tolerance, and the diameter of the optical lens mating surface adopts f7 tolerance;

[0017] The lens mating surface of the lens barrel is coated with silicone rubber with a thickness of 0.05 mm. This silicone rubber is applied in three evenly distributed locations on the lens mating surface (dividing the lens mating surface into six equal parts, each coated with silicone rubber at intervals with a thickness of 0.05 mm). During installation, the center offset of each lens is adjusted to ensure the optical parameters of the lens meet the usage requirements. Then, the lenses are removed one by one, and inward and outward arrow marks are made on their sides with a marker. Black silicone rubber is then applied evenly in three locations on the lens mating surface, with a thickness of approximately 0.05 mm. After coating, the optical lenses are gently placed into the lens barrel according to the side arrow marks, completing the assembly of the optical lens. Optical lenses assembled using these steps exhibit strong resistance to deformation and are stable and reliable.

[0018] The present invention also provides a method for installing an attitude sensor using the above-described mounting structure suitable for attitude sensors, which includes the following steps:

[0019] 1) The optical lens of the attitude sensor is installed inside the lens barrel, and the lens barrel is fixed inside the housing through the optical lens mounting surface and the optical lens mating surface; the electronic unit of the attitude sensor is installed inside the encapsulation reinforcement box, and the encapsulation reinforcement box is installed on the housing through the printed circuit board mounting surface.

[0020] 2) Fix the extinction grating of the attitude sensor inside the housing via the extinction grating connecting surface;

[0021] 3) The shell is mounted on the spacecraft via the external mounting surface.

[0022] The beneficial effects of this invention are as follows:

[0023] By incorporating a support, a lens tube, and a reinforced encapsulation box, this invention ensures the stability and reliability of the attitude sensor under conditions of large vibrations, strong impacts, and wide temperature variations, thus meeting usage requirements.

[0024] The optical lens's resistance to deformation is enhanced by methods such as precision tolerance design (G7 / f7) and uniform sealing of each optical lens.

[0025] By increasing the thickness of the printed circuit board and improving the flatness of the mounting position (0.04mm), the printed circuit board is guaranteed to be stress-free during mounting, thereby improving the stability of electronic components.

[0026] By adding a first thermal pad vertically to the (heavy) components on the printed circuit board and controlling the compression of the first thermal pad, the thermodynamic resistance of the printed circuit board is enhanced. The first thermal pad also plays a role in heat conduction and buffering, effectively reducing the stress on the solder of the heavy components on the printed circuit board, enhancing the deformation resistance of the components on the printed circuit board, and transferring the heat of the components to the support and aircraft mounting platform, thereby reducing the temperature rise and overall deformation of the attitude sensor.

[0027] By designing encapsulation reinforcement boxes around each printed circuit board, each printed circuit board becomes an encapsulated assembly with a box, which can greatly increase the rigidity of the printed circuit board.

[0028] This invention addresses the potential for significant damage to attitude sensors caused by high-frequency impacts by adding thermal pads and transition components, effectively reducing the impact of high-frequency impacts on attitude sensors. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the support structure;

[0031] Figure 2 This is a cross-sectional view of the microscope tube.

[0032] Figure 3 This is a schematic diagram of the microscope tube structure;

[0033] Figure 4 This is a structural diagram of the encapsulation reinforcement box;

[0034] Figure 5 It is a cross-sectional view of the installation of the printed circuit board and the encapsulation reinforcement box;

[0035] Figure 6 This is a schematic diagram of the transition component installation;

[0036] Figure 7 This is a schematic diagram of the installation of the transition piece from another perspective;

[0037] In the diagram: 1. Support; 1-1. Grate connecting surface; 1-2. Optical lens fastening surface; 1-3. Optical lens mating surface; 1-4. Printed circuit board fastening surface; 1-5. External mounting surface; 1-6. Housing; 2. Lens barrel; 2-1. Lens barrel lens mating surface; 3. Optical lens; 3-1. Optical lens mating surface; 4. Printed circuit board; 5. First thermal pad; 6. Box body; 6-1. Printed circuit board mounting surface; 7. Second thermal pad; 9. Screw with flat washer and spring washer; 10. Transition piece; 11. Silicone rubber. Detailed Implementation

[0038] 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.

[0039] Example 1

[0040] See Figures 1-7 An installation structure suitable for attitude sensors includes a support 1, a lens barrel 2, and a sealing reinforcement box.

[0041] The support 1 includes a housing 1-6, within which are provided an anti-glare grating connecting surface 1-1, an optical lens fixing surface 1-2, an optical lens mating surface 1-3, a printed circuit board fixing surface 1-4, and an external mounting surface 1-5. The anti-glare grating of the attitude sensor is fixed to the housing 1-6 via the anti-glare grating connecting surface 1-1. The optical lens 3 of the attitude sensor is installed inside the lens barrel 2 via the optical lens mating surface 3-1 and the lens barrel mating surface 2-1. The lens barrel 2 is fixed inside the housing 1-6 via the optical lens fixing surface 1-2 and the optical lens mating surface 1-3 (the radial fixation of the lens barrel 2 is a hole-shaft fit, and the axial fixation is achieved by bolt tightening). The electronic unit of the attitude sensor is installed inside a packaging reinforcement box, which is installed on the housing 1-6 via the printed circuit board fixing surface 1-4. The housing 1-6 is mounted on the spacecraft via the external mounting surface 1-5.

[0042] The electronics unit includes a printed circuit board 4 and components located on the printed circuit board 4; each printed circuit board 4 corresponds to a package reinforcement box (the corresponding package reinforcement box is designed according to the shape and size of each printed circuit board). The package reinforcement box includes a box body 6 and a first thermal pad 5; the printed circuit board 4 is mounted on the printed circuit board mounting surface 6-1 on the box body 6. The first thermal pad 5 is placed inside the box body 6 and below the printed circuit board 4, transferring the heat of the components on the printed circuit board 4 to the box body 6. The box body 6 is mounted on the printed circuit board fastening surface 1-4 of the housing 1-6 via a transition piece 10 and screws 9 with flat washers and spring washers, and a second thermal pad 7 is provided between the box body 6 and the housing 1-6. The second thermal pad, placed between the package reinforcement box and the housing 1-6 of the support 1, can conduct the heat of the components on the printed circuit board to the support 1, and then guide it along the support 1 to the attitude sensor mounting platform, effectively ensuring the thermal balance inside the attitude sensor. Through simulation and actual testing, the temperature rise of the 12W attitude sensor does not exceed 10℃. When the attitude sensor is subjected to high-frequency impact, the transition component 10 will partially attenuate the magnitude of the high-frequency impact, thereby ultimately protecting the components on the printed circuit board.

[0043] Example 2

[0044] Unlike Example 1, the compression of the first thermal pad 5 is 10%–15% to enhance the thermodynamic resistance of the printed circuit board 4. The thickness of the printed circuit board 4 is not less than 2 mm; the flatness of the fixed surface 1-4 and the mounting surface 6-1 of the printed circuit board is not greater than 0.04 mm. This improves the deformation resistance of the printed circuit board 4 and reduces the internal stress during installation and fastening, thereby reducing the stress on the solder feet of the soldered components on the printed circuit board 4.

[0045] Example 3

[0046] Unlike Example 1, the first-order mode of support 1 is higher than the highest vibration frequency of the attitude sensor, thus preventing resonance points from occurring across the entire frequency range. This is because when support 1 is imported into finite element simulation software for modal simulation, the attitude sensor's vibration frequency range is 20–2000 Hz, and the first-order mode of support reaches above 2000 Hz, thus preventing resonance points across the entire frequency range. Support 1 is the final supporting unit for all components in the attitude sensor, including the extinction grating, optical lens, and electronic units. If the attitude sensor's vibration frequency range is less than 2000 Hz, the first-order mode of support 1 can be reduced accordingly, as long as it is ensured that the first-order mode of support 1 is higher than the highest vibration frequency of the attitude sensor. This structure ensures the stability and reliability of the attitude sensor under conditions of large vibrations, strong impacts, and wide temperature variations, meeting the usage requirements.

[0047] Example 4

[0048] The lens barrel 2 contains a lens mating surface 2-1 and an optical lens mating surface 3-1. The diameter of the lens mating surface 2-1 is within the G7 tolerance, while the diameter of the optical lens mating surface 3-1 is within the f7 tolerance. A 0.05mm thick layer of silicone rubber 11 is coated onto the lens mating surface 2-1. There are three locations of silicone rubber 11, evenly distributed on the lens mating surface 2-1 (dividing the lens mating surface 2-1 into six equal parts, with each part coated with 0.05mm thick silicone rubber 11 at intervals).

[0049] Example 5

[0050] A method for installing an attitude sensor includes the following steps:

[0051] 1) The optical lens of the attitude sensor is installed inside the lens barrel, and the lens barrel is fixed inside the housing through the optical lens mounting surface and the optical lens mating surface; the electronic unit of the attitude sensor is installed inside the encapsulation reinforcement box, and the encapsulation reinforcement box is installed on the housing through the printed circuit board mounting surface.

[0052] The process of installing the optical lens of the attitude sensor inside the lens barrel, and fixing the lens barrel to the housing via the optical lens fastening surface and the optical lens mating surface, involves the following steps: adjusting the center offset of each lens to ensure that the optical parameters meet the usage requirements; then, removing the optical lenses one by one and marking their sides with arrows; applying black silicone rubber to three evenly distributed points on the lens mating surface 2-1 of the lens barrel, with a thickness of approximately 0.05 mm and uniform application; after coating, gently placing the optical lenses into the lens barrel 2 according to the side arrow markings to complete the assembly of the optical lenses; the optical lens assembled using the above steps has strong resistance to deformation and is stable and reliable.

[0053] The electronic unit of the attitude sensor is housed within a reinforced enclosure, which is then mounted on the housing via a printed circuit board (PCB) fastening surface. The process involves: first, attaching the first thermal pad 5 to the components on the PCB 4; then placing both together into the enclosure 6; and finally, using screws 9 with flat and spring washers to secure the PCB 4 with the first thermal pad 5 to the enclosure 6, making them a unified unit. Next, a second thermal pad 7 is installed between the enclosure 6 and the housing 1-6. Finally, using a transition piece 10 and screws with flat and spring washers, the enclosure 6 is mounted onto the PCB fastening surface 1-4 of the support 1, completing the reinforced enclosure of the PCB 4. This enclosure structure significantly improves the rigidity of the PCB 4, providing excellent protection for the components and their soldered pins under conditions of high vibration and strong impact. By using the first thermal pad 5 and the second thermal pad 7, the heat generated by the components is transferred to the housing 1-6 and subsequently to the aircraft, effectively dissipating the heat and preventing uneven heat distribution that could cause localized deformation of the attitude sensor and affect measurement accuracy. Through simulation and actual testing, the temperature rise of the 12W attitude sensor does not exceed 10℃.

[0054] 2) Fix the extinction grating of the attitude sensor inside the housing 1-6 through the extinction grating connecting surface 1-1.

[0055] 3) Install the shell 1-6 onto the spacecraft via the external mounting surface 1-5.

[0056] The mounting structure has been applied to attitude sensors in multiple aerospace projects, withstanding large vibrations, strong impacts, and wide temperature variations in the space environment, meeting usage requirements. The structural form and style of the support can be modified according to the specific installation method and performance requirements of the actual attitude sensor. Moreover, this structure can also be used in other equipment in harsh space, marine, and terrestrial environments.

[0057] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0058] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A mounting structure suitable for an attitude sensor, characterized in that: Includes support, lens barrel, and encapsulation reinforcement box; The support includes a housing, and the housing is provided with an anti-glare grating connecting surface, an optical lens fastening surface, an optical lens mating surface, a printed circuit board fastening surface, and an external mounting surface; The attitude sensor's extinction grating is fixed inside the housing via the extinction grating connecting surface; the attitude sensor's optical lens is installed inside the lens barrel via the optical lens mating surface and the lens barrel mating surface, and the lens barrel is fixed inside the housing via the optical lens fastening surface and the optical lens mating surface; the attitude sensor's electronic unit is installed inside the encapsulation reinforcement box, and the encapsulation reinforcement box is installed on the housing via the printed circuit board fastening surface; the housing is installed on the spacecraft via the external mounting surface; The electronics unit includes a printed circuit board and components located on the printed circuit board; each printed circuit board corresponds to a packaging reinforcement box; the packaging reinforcement box includes a box body and a first thermal pad; the printed circuit board is mounted on the printed circuit board mounting surface on the box body; the first thermal pad is placed inside the box body and located under the printed circuit board to transfer the heat of the components on the printed circuit board to the box body. The box is mounted on the printed circuit board mounting surface of the shell.

2. The mounting structure for an attitude sensor according to claim 1, characterized in that: A second thermal pad is provided between the box body and the shell to transfer the heat of the box body to the shell.

3. The mounting structure for a posture sensor according to claim 1 or 2, characterized in that: The box is connected to the housing via transition pieces and screws with flat washers and spring washers.

4. The mounting structure for a posture sensor according to claim 1, characterized by: The compression of the first thermal pad is 10% to 15%, that is, the depth of the reinforced inner cavity is the height of the printed circuit board components plus 85% to 90% of the thermal pad thickness.

5. The mounting structure for a posture sensor according to claim 1, characterized by: The thickness of the printed circuit board shall not be less than 2mm.

6. The mounting structure for a posture sensor according to claim 1, characterized by: The flatness of the printed circuit board fastening surface and the printed circuit board mounting surface shall not exceed 0.04mm.

7. The mounting structure for a posture sensor according to claim 1, characterized by: The first-order mode of the support is greater than the highest vibration frequency of the attitude sensor.

8. The mounting structure for a posture sensor according to claim 1 or 7, characterized by: The lens barrel is provided with a lens barrel mating surface and an optical lens mating surface; the diameter of the lens barrel mating surface is G7 tolerance, and the diameter of the optical lens mating surface is f7 tolerance. The lens mating surface of the lens barrel is coated with silicone rubber with a thickness of 0.05 mm; the silicone rubber is present in 3 places and is evenly distributed on the lens mating surface of the lens barrel.

9. A method of mounting a posture sensor using the mounting structure for a posture sensor according to any one of claims 1 to 8, characterized by: Includes the following steps: 1) The optical lens of the attitude sensor is installed inside the lens barrel, and the lens barrel is fixed inside the housing through the optical lens mounting surface and the optical lens mating surface; the electronic unit of the attitude sensor is installed inside the encapsulation reinforcement box, and the encapsulation reinforcement box is installed on the housing through the printed circuit board mounting surface. 2) Fix the extinction grating of the attitude sensor inside the housing via the extinction grating connecting surface; 3) The shell is mounted on the spacecraft via the external mounting surface.

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