Flexible installation thermal protection door for satellite remote sensing camera

Abstract

The invention discloses a flexible installation thermal protection door for an on-satellite remote sensing camera, and belongs to the technical field of on-satellite remote sensing camera design. The thermal protection door comprises a flexible unloading mounting structure, a thermal protection door plate, a thermal protection door plate connecting structure, a thermal door driving mechanism, an unloading spring structure and an electromagnet locking and unlocking structure. One end of the flexible unloading installation structure is clamped between the unloading spring structure and the thermal protection door plate, and the other end of the flexible unloading installation structure is provided with a locking and unlocking structure which is connected with a satellite deck or a camera lens cone. The hot door driving mechanism is connected with the thermal protection door plate through the thermal protection door plate connecting structure and provides driving force for opening and closing of the thermal protection door plate. The thermal protection door has the advantages of being light in weight, high in thermal door temperature stability, high in thermal door connector adaptability and high in thermal protection door reliability.

Description

Technical Field

[0001] The invention relates to a flexibly mounted thermal protection door for a satellite remote sensing camera, belonging to the technical field of satellite remote sensing camera design. Background Art

[0002] With the continuous development of aerospace technology, space remote sensing camera ground observation is an important means of obtaining ground information. Ultra-low orbit satellites have good ground imaging observation performance and a short revisit period, which improves the ability to obtain information in hot and sensitive areas. They have high application value and huge potential. They are currently a hot area of ​​aerospace work at home and abroad. Ultra-low orbit satellites refer to satellite platforms deployed at an orbital altitude of 120-300 kilometers. Ultra-low orbit satellites need to overcome unfavorable factors such as low-orbit atmospheric resistance, low-altitude harsh space environment, and frequent disturbances of satellite attitude caused by this. Ultra-low orbit satellites have low orbital altitudes and are suitable for ground observation, scientific exploration and low-altitude environment research. Compared with low, medium and high orbit satellites, they have good imaging resolution, high image quality, and accurate detection data. They can enhance imaging resolution, reduce system power consumption, and obtain ground and sea surface information in a timely manner. They have high application value in remote sensing surveys.

[0003] Satellites operating in ultra-low orbits will encounter a unique neutral atmosphere. The different angles of sunlight projection cause the atmosphere to have seasonal changes, local time changes, and changes with latitude. The thermal balance inside the satellite is determined by the solar radiation in the low orbit, the reflection of solar radiation by the earth and the atmosphere, the radiation of the earth's atmosphere itself, and the thermal radiation of the satellite itself. Ultra-low orbit satellites are more affected by the earth's infrared and earth-reflected external heat flux than conventional orbits. The external heat flux at the camera's light entrance changes dramatically, the camera's shadow area and the sun-exposed area appear alternately, and the thermal environment is complex and harsh. When the external heat flux changes dynamically, the optical, structural and other parameters of the imaging optical devices in the camera system structure will be affected by the temperature effect and change, which in turn affects the imaging quality of the system. In order to reduce the impact of the external heat flux introduced from the camera's light entrance, the technical means of installing a thermal protection door at the light entrance of the remote sensing satellite camera can be used to achieve this.

[0004] Generally speaking, the working time of the thermal protection door accompanies the entire life cycle of the satellite, and the high reliability of the thermal protection door is the key difficulty in the design process. Through research, in the design process of thermal protection doors for on-board remote sensing cameras at home and abroad, in order to fully ensure that the thermal protection door will not have a large dynamic response in the launch phase and thus have a large-scale impact on the drive mechanism, a rigid connection design is generally used for the auxiliary fixation of the hot spot. In order to ensure that the satellite can be unlocked normally after entering orbit, the installation points of the rigid connection design generally have extremely high dimensional and geometric tolerances, which brings great difficulties to the design, manufacture and assembly of the thermal protection door, and also brings certain risks and hidden dangers to the fixation, unlocking and on-orbit operation of the thermal protection door. In order to ensure the reliability of the hot spot drive mechanism throughout its life cycle, the main body of the drive mechanism is usually designed as a high-rigidity frame body with a high structural fundamental frequency during the design of the hot spot drive mechanism. Usually, the high-rigidity design will increase the weight of the hot spot assembly. This puts forward extremely high dimensional and geometric tolerances for the structural installation of the thermal protection door; due to the rigid connection, the number of locking and unlocking mechanisms for auxiliary connection and fixing of the hot spot in the domestic thermal protection door assembly is often large, which inevitably brings the risk of reduced reliability of the thermal protection door assembly. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and propose a flexibly mounted thermal protection door for a satellite remote sensing camera, which has the advantages of light weight, high thermal stability and high reliability of the thermal protection door.

[0006] The technical solution of the present invention is:

[0007] A thermal protection door for a satellite remote sensing camera with flexible installation, comprising a flexible unloading installation structure, a thermal protection door panel, a thermal protection door panel connection structure, a thermal drive mechanism, an unloading spring structure, and an electromagnet locking and unlocking structure;

[0008] The shape of the thermal protection door plate is the same as the outer end surface of the lens barrel of the onboard remote sensing camera. When the onboard remote sensing camera is not working, the inner surface of the thermal protection door plate covers the lens barrel to provide thermal protection for the lens barrel.

[0009] The unloading spring structure is located at the outer edge of the inner surface of the door panel of the heat protection door;

[0010] One end of the flexible unloading installation structure is clamped between the unloading spring structure and the door plate of the thermal protection door, and the unloading spring structure and the unloading spring structure are fixed to the door plate of the thermal protection door by screws; the other end of the flexible unloading installation structure is equipped with a locking and unlocking structure;

[0011] The locking and unlocking structure is connected to the satellite cabin panel or the camera lens barrel;

[0012] One end of the heat protection door panel connection structure is installed on the outer edge of the heat protection door panel, and the other end is connected to the heat drive mechanism;

[0013] The thermal drive mechanism is fixed on the satellite cabin panel and is used to provide a driving force for the thermal protection door panel to open and close.

[0014] Furthermore, the locking and unlocking structure includes an electromagnetic pure iron sheet and an electromagnet; wherein the electromagnet is installed on an inactive structural body on the satellite, and the electromagnet pure iron sheet is installed on a flexible unloading mounting structure; by powering on and off the electromagnet, the electromagnet and the electromagnet pure iron sheet are attracted and separated.

[0015] Furthermore, the number of locking and unlocking structures, the relative position of the flexible unloading mounting structure where they are located, and the thermal protection door panel connection structure are determined through finite element simulation, specifically: a finite element model of the thermal protection door is established, and a multi-working condition simulation is performed in which the flexible unloading mounting structure where the electromagnet locking and unlocking structure is located is installed at different positions on the outer edge of the thermal protection door panel and different numbers of electromagnet locking and unlocking structures are used to obtain the size of the electromagnet suction force required to lock the thermal protection door panel, and the working condition in which the total weight of the locking and unlocking structure is minimized when the suction force meets the mechanical conditions of the thermal protection door is selected, and the working condition is installed for setting.

[0016] Furthermore, the electromagnet of the locking and unlocking structure is installed on the outside of the satellite cabin panel, and the thermal drive mechanism is installed on the inside of the satellite cabin panel, thereby reducing the impact on the overall size of the satellite.

[0017] Furthermore, during the satellite launch phase, the electromagnet locking and unlocking structure is energized, the electromagnet generates magnetic force, attracts the electromagnet pure iron sheet, and locks the thermal protection door panel; after entering the satellite orbit, the electromagnet locking and unlocking structure is powered off, and the thermal drive mechanism works to generate driving force to open or close the thermal protection door panel.

[0018] Furthermore, the thermal protection door panel is a honeycomb sandwich composite material panel, and a protective structure is attached to the outer surface to achieve thermal protection for the remote sensing camera.

[0019] Furthermore, the protective structure is bonded to the outer surface of the thermal protection door panel by means of Velcro.

[0020] Furthermore, the main body of the thermal drive mechanism adopts a 3D printed dot matrix space grid configuration, and modular motors and gears are selected as active parts of the thermal drive mechanism.

[0021] Furthermore, the flexible unloading installation structure is a sheet-like structure with an unloading groove on the surface, and the size of the unloading groove is designed according to the maximum deformation of the structure under the premise of satisfying the reliability of the structure.

[0022] Furthermore, the unloading spring structure is a bow-shaped structure, and the material is beryllium bronze.

[0023] The advantages of the present invention compared with the prior art are:

[0024] (1) The present invention simultaneously meets the key requirements of the thermal protection door of the space camera: light weight, high temperature stability, strong interface adaptability, high reliability of the thermal protection door, and solves the technical defects of the existing thermal protection door components.

[0025] (2) The present invention adopts the application of a flexible mounting structure between two locking and unlocking structures and the satellite / camera main body structure, which reduces the number of locking and unlocking structures by 50% compared with a similar product; the thermal protection door deployment and closing experiment is carried out using ground gravity unloading, which reduces the weight of the thermal drive mechanism by 50%. The total weight of the thermal protection door assembly based on the present invention is low, about 1 / 3 to 1 / 2 of the traditional design, which reduces the mechanical burden of the camera body, saves the resources of the entire machine, and leaves more room for the main body design.

[0026] (3) The heat protection door panel and the heat protection door panel connection structure designed by the present invention are made of lightweight and high-strength titanium alloy material. By optimizing the structural design, the weight of the connection structure is reduced to the greatest extent. At the same time, the processing accuracy requirements are low, the processing technology is simple, and the time and economic costs are low, which is conducive to improving the efficiency of the enterprise.

[0027] (4) Compared with the locking and unlocking mechanism of traditional pyrotechnics, the present invention uses an electromagnet in combination with an electromagnetic pure iron sheet as the locking and unlocking mechanism. The electromagnet and the electromagnetic pure iron sheet can be repeatedly used on the ground and can be reused in multiple stages such as components, single machines, complete machines, and complete satellites. The consistency of ground test conditions at different stages is fully maintained, and the use cost of the locking and unlocking mechanism is greatly reduced.

[0028] (5) The present invention, on the premise of fully reducing the weight of the thermal structure components, that is, fully reducing the weight of the thermal drive mechanism device, will greatly reduce the difficulty of the motor design, shaft and bearing design, and gear design of the thermal drive mechanism, and use titanium alloy as the structure of the drive mechanism support body. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 This is a front schematic diagram of the structure of a flexible installation thermal protection door assembly for a satellite remote sensing camera according to an embodiment of the present invention;

[0031] Figure 2This is a schematic diagram of the back side of the structure of the flexible installation thermal protection door assembly of the onboard remote sensing camera according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of a thermal protection space environment protection structure according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of the electromagnet locking and unlocking mechanism according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the connection structure of the door panels of the heat protection door according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the design principle of the unloading groove of the flexible unloading installation structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0037] The present invention proposes a thermal protection door assembly for a satellite remote sensing camera that is flexibly mounted, which is described in detail through an embodiment:

[0038] According to the camera aperture requirements, the diameter of the camera's thermal protection door panel must be greater than 800mm, the camera thermal protection door drive must be installed on the inside of the satellite cabin panel, and the auxiliary locking and unlocking structure must be installed on the outside of the satellite cabin panel to minimize the impact on the overall dimensions of the satellite. The thermal protection door assembly designed based on the present invention has an overall weight of 6Kg. Taking the thermal protection door assembly as an example, the implementation method is specifically described:

[0039] The component Figure 1 to Figure 4 As shown, it includes a flexible unloading installation structure 1, a heat protection door panel 2, a heat protection door panel connection structure 3, a heat drive mechanism 4, a beryllium bronze large displacement unloading spring structure 5, an electromagnet locking and unlocking mechanism 6 and a heat protection space environment protection structure 7. The flexible unloading installation structure 1 with an unloading groove thin sheet structure is connected to the heat protection door panel 2 of a lightweight and high-strength honeycomb sandwich composite material plate by screws, the heat protection door panel connection structure 3 with a lightweight design is connected to the heat protection door panel 2 and the heat drive mechanism 4 respectively by screws, the beryllium bronze large displacement unloading spring structure 5 with a thin sheet bow structure is connected to the heat protection door panel 2 by screws, the locking and unlocking structure 6 is connected to the satellite cabin panel or the camera lens barrel structure by screws, and the heat protection door space environment protection structure 6 is bonded to the outer side of the heat protection door panel 2 by nylon buckle.

[0040] The thermal protection door panel 2 is the main structure of the assembly and a functional component of the thermal protection door assembly. It supports all parts of the entire assembly and adopts a lightweight, high-strength, high-rigidity honeycomb sandwich carbon fiber skin with high atomic oxygen protection capability to achieve the core function of thermal protection of the thermal flow environment outside the remote sensing satellite lens. The flexible unloading installation structure 1, the thermal protection door panel connection structure 3, the beryllium bronze large displacement unloading spring knot 5 and the thermal protection space environment protection structure 7 are directly connected to the thermal protection door panel 2, and the thermal drive mechanism 4 and the electromagnet locking and unlocking mechanism 6 are indirectly connected to the thermal protection door panel 2 through components.

[0041] The finite element model of the thermal protection door is established, and the electromagnet suction force required to lock the thermal protection door panel under different working conditions of the electromagnet locking and unlocking structure 6 installed at different positions and with different numbers is compared through simulation analysis. The two electromagnet locking and unlocking mechanisms 6 with the smallest total weight of the locking and unlocking structure under the mechanical conditions of the product are selected. The results of the simulation analysis determine that the two flexible unloading installation structures 1 are installed at two positions with an angle of 120° to the thermal drive mechanism 4. Figure 4 As shown, it includes an electromagnetic pure iron sheet 8 and an electromagnet 9. This mechanism is simple in composition and fully functional. The electromagnet 9 is powered on and off to achieve the attraction and separation of the electromagnet 9 and the electromagnetic pure iron sheet 8; wherein the electromagnet 9 is installed on an inactive structural body such as a satellite cabin board or a camera structural body, and the electromagnetic pure iron sheet 8 is connected to the thermal protection door panel 2 through a flexible unloading installation structure 1. The electromagnet 9 is used to solve the problem of the ground on-orbit consistency of the mechanism. By powering on and off the electromagnet, the locking and unlocking mechanism can be operated multiple times, and there is no need to replace the locking and unlocking structure after completing the ground unlocking test, which reduces the time cost and economic cost.

[0042] like Figure 6 As shown, the maximum deformation of the flexible unloading installation structure is calculated through simulation analysis, and the unloading groove width D and L of the thin sheet-like flexible unloading installation structure 1 are designed under the premise of satisfying structural reliability.

[0043] The main body of the hot drive mechanism 4 adopts a 3D printed dot matrix space grid configuration, which is low in weight and high in rigidity. Modular motors and gears are selected as the active parts of the drive mechanism to reduce the time and economic cost of selecting the parts of the drive mechanism.

[0044] Heat protection door panel connection structure 3, such as Figure 5As shown, it includes an upper swing arm 10 and a lower swing arm 11, and the two parts are connected by screws. During the assembly process, the upper swing arm 10 is assembled with the thermal protection door panel 2, and then the lower swing arm 11 is assembled with the thermal drive mechanism 4. Finally, in the final assembly process, the lower swing arm 11 passes through the satellite cabin board and is screwed to the upper swing arm 10, and finally the thermal drive mechanism 4 realizes the opening and closing function of the thermal protection door panel 2.

[0045] The beryllium bronze large displacement unloading spring 5 is combined with the flexible unloading mounting structure 1, and the installation sequence is that the flexible unloading mounting structure 1 is clamped between the beryllium bronze large displacement unloading spring 5 and the thermal protection door panel 2, and the two are fixed to the thermal protection door panel 2 by screws, thereby unloading the configuration of the impact of the large displacement of the thermal protection door panel 2 under mechanical conditions on the cabin structure.

[0046] The material of the thermal protection space environment protection structure 7 is Beta cloth, which is used to resist atomic oxygen.

[0047] The working principle of the thermal protection door is as follows: during the satellite launch phase, the electromagnet locking and unlocking structure 6 is energized, the electromagnet generates magnetic force, attracts the electromagnet pure iron sheet 8, and then locks the thermal protection door panel 2; after entering the satellite orbit, the electromagnet locking and unlocking structure 6 is de-energized, and the opening or closing of the thermal protection door panel 2 is achieved through the rotation of the motor and gears in the thermal drive mechanism 4.

[0048] The above-described embodiments are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible thermal protection door for a satellite remote sensing camera, characterized in that: It includes a flexible unloading installation structure, a heat protection door panel, a heat protection door panel connection structure, a heat drive mechanism, an unloading spring structure, and an electromagnet locking and unlocking structure; The shape of the thermal protection door plate is the same as the outer end surface of the lens barrel of the onboard remote sensing camera. When the onboard remote sensing camera is not working, the inner surface of the thermal protection door plate covers the lens barrel to provide thermal protection for the lens barrel. The unloading spring structure is located at the outer edge of the inner surface of the door panel of the heat protection door; One end of the flexible unloading installation structure is clamped between the unloading spring structure and the door plate of the thermal protection door, and the unloading spring structure and the unloading spring structure are fixed to the door plate of the thermal protection door by screws; The other end of the flexible unloading installation structure is equipped with a locking and unlocking structure; The locking and unlocking structure is connected to the satellite cabin panel or the camera lens barrel; One end of the heat protection door panel connection structure is installed on the outer edge of the heat protection door panel, and the other end is connected to the heat drive mechanism; The thermal drive mechanism is fixed on the satellite cabin panel and is used to provide a driving force for the thermal protection door panel to open and close.

2. The flexible thermal protection door for satellite remote sensing cameras according to claim 1 is characterized in that: The locking and unlocking structure includes an electromagnetic pure iron sheet and an electromagnet; wherein the electromagnet is installed on an inactive structural body on the satellite, and the electromagnetic pure iron sheet is installed on a flexible unloading installation structure; by powering on and off the electromagnet, the electromagnet and the electromagnetic pure iron sheet are attracted and separated.

3. The flexible thermal protection door for mounting a remote sensing camera on a satellite according to claim 1 or 2, characterized in that: The number of locking and unlocking structures and the relative position of the flexible unloading installation structure where they are located and the thermal protection door panel connection structure are determined through finite element simulation, specifically: a finite element model of the thermal protection door is established, and a multi-working condition simulation is performed in which the flexible unloading installation structure where the electromagnet locking and unlocking structure is located is installed at different positions on the outer edge of the thermal protection door panel and different numbers of electromagnet locking and unlocking structures are used to obtain the size of the electromagnet suction force required to lock the thermal protection door panel, and the working condition in which the total weight of the locking and unlocking structure is minimized when the suction force meets the mechanical conditions of the thermal protection door is selected, and the working condition is installed for setting.

4. The flexible thermal protection door for mounting a remote sensing camera on a satellite according to claim 2, characterized in that: The electromagnet of the locking and unlocking structure is installed on the outside of the satellite cabin panel, and the thermal drive mechanism is installed on the inside of the satellite cabin panel to reduce the impact on the overall size of the satellite.

5. The flexible thermal protection door for mounting a remote sensing camera on a satellite according to claim 2, characterized in that: During the satellite launch phase, the electromagnet locking and unlocking structure is energized, the electromagnet generates magnetic force, attracts the electromagnet pure iron sheet, and locks the thermal protection door panel; After entering the satellite orbit, the electromagnet locking and unlocking structure is powered off, and the thermal drive mechanism works to generate driving force to open or close the thermal protection door panel.

6. The flexible thermal protection door for mounting a remote sensing camera on a satellite according to claim 1, characterized in that: The thermal protection door panel is a honeycomb sandwich composite material panel with a protective structure attached to the outer surface to achieve thermal protection for the remote sensing camera.

7. The flexible thermal protection door for mounting a remote sensing camera on a satellite according to claim 6, characterized in that: The protective structure is bonded to the outer surface of the thermal protection door panel by Velcro.

8. The flexible thermal protection door for mounting a remote sensing camera on a satellite according to claim 1, characterized in that: The main body of the thermal drive mechanism adopts a 3D printed dot matrix space grid configuration, and modular motors and gears are selected as active parts of the thermal drive mechanism.

9. The flexible thermal protection door for mounting a remote sensing camera on a satellite according to claim 1, characterized in that: The flexible unloading installation structure is a sheet-like structure with an unloading groove on the surface. The size of the unloading groove is designed according to the maximum deformation of the structure while satisfying the reliability of the structure.

10. The flexible thermal protection door for satellite remote sensing cameras according to claim 1, characterized in that: The unloading spring structure is a bow-shaped structure and is made of beryllium bronze.

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