A thermal analysis method for power tools used in on-orbit maintenance of space with uncertain heat flow

Abstract

The present invention discloses a thermal analysis method for an electric tool used for on-orbit maintenance in space with uncertain heat flow. The method determines the working mode of the electric tool according to the working requirements of the electric tool outside the cabin; determines the position of the electric tool after leaving the cabin, mainly including the shielding by astronauts and spacecraft; establishes a thermal analysis matrix for the electric tool based on the working conditions of the electric tool leaving the cabin in the sunlit area and the shadowed area; determines the thermal simulation input and uses the thermal parameters and orbital parameters of the electric tool as thermal input, and performs simulation analysis of each thermal working condition in sequence in the thermal simulation analysis software. In the present invention, by establishing a working condition matrix of various illumination and shielding conditions under high and low temperature working conditions of the electric tool, the problem that the electric tool outside the cabin moves with the astronauts during maintenance outside the space station is solved, and the environment and working conditions outside the cabin are complex and irregular, making it difficult to use conventional single-machine thermal analysis methods outside the cabin, that is, to perform thermal analysis under the conditions of position determination and heat flow simulation.

Description

Technical Field

[0001] The present invention relates to the technical field of extravehicular maintenance of space stations, and in particular to a thermal analysis method for uncertain heat flow of an electric tool used for on-orbit maintenance of space. Background Art

[0002] Power tools used for on-orbit maintenance in space are handheld electromechanical devices that accompany astronauts during extravehicular maintenance to install and replace fasteners on extravehicular equipment. To ensure that these tools can function properly in the cold, dark environment outside the spacecraft, simulation analysis of their thermal control scheme is required to simulate their feasibility under real-world orbital conditions. During the space station's in-orbit operation, its environment is affected by the Earth, with the illuminated / shadowed areas alternating between hot and cold every 90 minutes. The tools travel with the astronauts during extravehicular maintenance. During transfers and operations, the tool's position and obstruction relationships change at any time. The extravehicular environment and operating conditions are complex and irregular, making it difficult to directly determine the heat flux outside the environment. This makes it difficult to perform thermal analysis using the stable thermal flow conditions of conventional fixed extravehicular stand-alone products. Therefore, a thermal analysis method is needed for the uncertain on-orbit heat flux of power tools used for extravehicular maintenance on the space station. Summary of the Invention

[0003] The purpose of the present invention is to solve the above problems and to propose a thermal analysis method for uncertain heat flow of electric tools used for on-orbit maintenance in space.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A thermal analysis method for uncertain heat flow of an electric tool for on-orbit maintenance in space, comprising the following steps:

[0006] Step 101: Determine the out-of-cabin working mode of the electric tool; determine the working mode of the electric tool, including out-of-cabin unpowered transfer mode, out-of-cabin standby mode, and out-of-cabin timed working mode;

[0007] Step 102: Determine the position and working condition of the power tool; determine the position of the power tool after leaving the cabin, mainly including whether it is blocked by the astronauts and the spacecraft;

[0008] Step 103: Establish a thermal condition matrix; based on the operating conditions of the power tool's cabin exit in the sunlit area and the cabin exit in the shadowed area, establish a thermal analysis matrix based on the power tool's operating mode, on-orbit shading, and cabin exit timing;

[0009] Step 104: Determine thermal simulation inputs; determine thermal environment parameters of the actual spacecraft orbit, operating mode and heat consumption distribution of the extravehicular power tool, and thermal control status of the extravehicular power tool itself;

[0010] Step 105: Thermal parameter setting: determining the thermal physical parameters and optical parameters of each component of the thermal model, including the density, specific heat capacity, thermal conductivity, solar absorptivity, and infrared emissivity of the material;

[0011] Step 106: Thermal condition simulation analysis: Substitute the parameters in the above steps into the thermal simulation software and simulate each thermal condition in turn.

[0012] Preferably, determining the out-of-cabin working mode of the power tool in step 101 specifically includes:

[0013] According to the working requirements of power tools, they need to be transferred to the extravehicular work point with the astronauts, turn on the power and install or remove the equipment fasteners. Therefore, the working modes include extravehicular unpowered transfer mode, extravehicular standby mode, and extravehicular timed work mode.

[0014] Preferably, determining the position working condition of the power tool in step 102 specifically includes:

[0015] The power tools move with the astronauts and are located near the spacecraft cabin wall for a long time. They are installed on the left side of the space suit when moving with the astronauts. When they arrive at the work point, they are located between the astronauts and the spacecraft. There are various obstruction conditions caused by different on-orbit positions, including no obstruction, obstruction by both the astronauts and the spacecraft, inside the spacecraft, and outside the spacecraft.

[0016] Preferably, the establishment of the thermal condition matrix in step 103 specifically includes:

[0017] Combined with the working conditions of the electric tool's cabin exit in the sunny area and the shadowed area, a thermal analysis matrix of the electric tool based on the working mode, on-orbit shading, and cabin exit timing is established, including multiple thermal analysis conditions of the electric tool under different working modes, different on-orbit shading, and different cabin exit timing.

[0018] Preferably, determining the thermal simulation input in step 104 specifically includes:

[0019] Determine the thermal environment parameters of the actual orbit of the spacecraft in which the power tool is located when it is working, including heat flux density and solar incidence angle; the thermal control of the power tool itself mainly includes determining basic information such as thermal power consumption, temperature index, and shell thermal resistance of the main heat-generating components.

[0020] Preferably, the thermal parameter setting in step 105 specifically includes:

[0021] The thermal physical parameters and optical parameters of each component of the thermal model are designed and selected. The thermal physical parameters are mainly the density, specific heat capacity, and thermal conductivity of the extravehicular power tool housing, motor, battery, thermal insulation component, and thermal pad material; the optical parameters are mainly the solar absorption ratio α of the extravehicular power tool housing surface and surrounding obstructions such as spacecraft and space suit surfaces. S , infrared emissivity ε.

[0022] Preferably, the thermal condition simulation analysis in step 106 is used to verify the rationality and feasibility of the thermal control solution of the power tool.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] In this application, the working mode of the electric tool is first determined according to the working requirements of the extravehicular electric tool, including the extravehicular unpowered transfer mode, the extravehicular standby mode, and the extravehicular timed working mode; the position of the electric tool after leaving the cabin is determined, mainly including the obstruction by astronauts and spacecraft; combined with the working conditions of the electric tool leaving the cabin in the sunlit area and the shadowed area, a thermal analysis matrix based on the working mode, on-orbit obstruction, and the timing of the extravehicular operation is established; the thermal simulation input is determined, including the thermal environment parameters of the actual orbit of the spacecraft, the working heat consumption distribution of the electric tool, and the thermal control of the extravehicular electric tool itself, and the thermal characteristic parameters of the model are determined, including the surface parameters of the thermal model of the electric tool, the density, specific heat capacity, thermal conductivity parameters of the materials of each component, and the solar absorption ratio α of the surface of the electric tool, space suit, and spacecraft materials. S , infrared emissivity ε; using the power tool's thermal parameters and orbital parameters as thermal inputs, the thermal simulation analysis software sequentially simulates each thermal operating condition. By establishing an operating condition matrix for the power tool under various conditions of illumination and shielding, under high and low temperature conditions, this solves the problem that extravehicular power tools move with astronauts during space station maintenance. The extravehicular environment and operating conditions are complex and irregular, making thermal analysis difficult using conventional extravehicular single-unit thermal analysis methods, which require fixed positions and simulated heat flows. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic flow chart of a thermal analysis method for uncertain heat flow of an on-orbit maintenance power tool for space provided by an embodiment of the present invention is shown;

[0026] Figure 2 It shows the position diagram outside the cabin of the electric tool for on-orbit maintenance in space provided by an embodiment of the present invention;

[0027] Figure 3 A matrix diagram of the out-of-cabin working conditions of an electric tool for on-orbit maintenance in space provided according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] See also Figure 1-3 , the present invention provides a technical solution:

[0030] A thermal analysis method for uncertain heat flow of an electric tool for on-orbit maintenance in space, comprising the following steps:

[0031] Step 101: Determine the out-of-cabin working mode of the electric tool; determine the working mode of the electric tool, including out-of-cabin unpowered transfer mode, out-of-cabin standby mode, and out-of-cabin timed working mode;

[0032] Step 102: Determine the position and working condition of the power tool; determine the position of the power tool after leaving the cabin, mainly including whether it is blocked by the astronauts and the spacecraft;

[0033] Step 103: Establish a thermal condition matrix; based on the operating conditions of the power tool's cabin exit in the sunlit area and the cabin exit in the shadowed area, establish a thermal analysis matrix based on the power tool's operating mode, on-orbit shading, and cabin exit timing;

[0034] Step 104: Determine thermal simulation inputs; determine thermal environment parameters of the actual spacecraft orbit, operating mode and heat consumption distribution of the extravehicular power tool, and thermal control status of the extravehicular power tool itself;

[0035] Step 105: Thermal parameter setting: determining the thermal physical parameters and optical parameters of each component of the thermal model, including the density, specific heat capacity, thermal conductivity, solar absorptivity, and infrared emissivity of the material;

[0036] Step 106: Thermal condition simulation analysis: Substitute the parameters in the above steps into the thermal simulation software and simulate each thermal condition in turn.

[0037] Specifically, such as Figure 1 and Figure 2 As shown, determining the out-of-cabin working mode of the power tool in step 101 specifically includes:

[0038] According to the working requirements of power tools, they need to be transferred to the extravehicular work point with the astronauts, turn on the power and install or remove the equipment fasteners. Therefore, the working modes include extravehicular unpowered transfer mode, extravehicular standby mode, and extravehicular sequence working mode. Among them, the extravehicular sequence working mode can consider the deviation working condition.

[0039] Specifically, such as Figure 1 and Figure 2 As shown, determining the position working condition of the power tool in step 102 specifically includes:

[0040] The power tool moves with the astronauts and is located near the spacecraft cabin wall for a long time. It is installed on the left side of the space suit when moving with the astronauts. When arriving at the work point, it is located between the astronauts and the spacecraft. There are various obstruction working conditions caused by different on-orbit positions, including no obstruction, obstruction by both the astronauts and the spacecraft, inside the spacecraft, and outside the spacecraft. In this embodiment, the spacecraft is the Chinese space station.

[0041] Specifically, such as Figure 1 and Figure 3 As shown, the establishment of the thermal condition matrix in step 103 specifically includes:

[0042] Combined with the working conditions of the electric tool's extravehicular activity in the sunny area and the shadowed area, a thermal analysis matrix of the electric tool based on the working mode, on-orbit shading, and extravehicular timing was established. This matrix includes multiple thermal analysis conditions of the electric tool under different working modes, different on-orbit shading, and different extravehicular timing, specifically involving 20 working conditions.

[0043] Specifically, such as Figure 1 and Figure 2 As shown, determining the thermal simulation input in step 104 specifically includes:

[0044] Determine the thermal environment parameters of the actual orbit of the spacecraft in which the power tool is located when it is working, including heat flux density and solar incidence angle; the thermal control of the power tool itself mainly includes determining basic information such as thermal power consumption, temperature index, and shell thermal resistance of the main heat-generating components.

[0045] Specifically, such as Figure 1 and Figure 2 As shown, the thermal parameter setting in step 105 specifically includes:

[0046] The thermal physical parameters and optical parameters of each component of the thermal model are designed and selected. The thermal physical parameters are mainly the density, specific heat capacity, and thermal conductivity of the extravehicular power tool housing, motor, battery, thermal insulation component, and thermal pad material; the optical parameters are mainly the solar absorption ratio α of the extravehicular power tool housing surface and surrounding obstructions such as spacecraft and space suit surfaces. S , infrared emissivity ε.

[0047] Specifically, such as Figure 1 and Figure 2 As shown, the thermal condition simulation analysis in step 106 is used to verify the rationality and feasibility of the thermal control solution of the power tool.

[0048] The present invention establishes an operating condition matrix for electric tools under various conditions of illumination and shielding under high and low temperature conditions, thereby solving the problem that extravehicular electric tools are transferred with astronauts during extravehicular maintenance on the space station, and the extravehicular environment and working conditions are complex and irregular, making it difficult to perform thermal analysis using conventional extravehicular single-machine thermal analysis methods, that is, conditions where the position is determined and the heat flow can be simulated.

[0049] The above description of the embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thermal analysis method for uncertain heat flow of power tools used for on-orbit maintenance in space, characterized by: The following steps are involved: Step 101: Determine the out-of-cabin working mode of the electric tool; determine the working mode of the electric tool, including out-of-cabin unpowered transfer mode, out-of-cabin standby mode, and out-of-cabin timed working mode; Step 102: Determine the position and working condition of the power tool; determine the position of the power tool after leaving the cabin, including whether it is blocked by the astronauts and the spacecraft; Step 103: Establish a thermal condition matrix; based on the operating conditions of the power tool's cabin exit in the sunlit area and the cabin exit in the shadowed area, establish a thermal analysis matrix based on the power tool's operating mode, on-orbit shading, and cabin exit timing; Step 104: Determine thermal simulation inputs; determine thermal environment parameters of the actual spacecraft orbit, operating mode and heat consumption distribution of the extravehicular power tool, and thermal control status of the extravehicular power tool itself; Step 105: Thermal parameter setting: determining the thermal physical parameters and optical parameters of each component of the thermal model, including the density, specific heat capacity, thermal conductivity, solar absorptivity, and infrared emissivity of the material; Step 106: Thermal condition simulation analysis: Substitute the parameters in the above steps into the thermal simulation software and simulate each thermal condition in turn.

2. The thermal analysis method for uncertain heat flow of a space on-orbit maintenance power tool according to claim 1, characterized in that: Determining the out-of-cabin working mode of the power tool in step 101 specifically includes: According to the working requirements of power tools, they need to be transferred to the extravehicular work point with the astronauts, turn on the power and install or remove the equipment fasteners. Therefore, the working modes include extravehicular unpowered transfer mode, extravehicular standby mode, and extravehicular timed work mode.

3. The thermal analysis method for uncertain heat flow of a space on-orbit maintenance power tool according to claim 1, characterized in that: Determining the position working condition of the power tool in step 102 specifically includes: The power tools move with the astronauts and are located near the spacecraft cabin wall for a long time. They are installed on the left side of the space suit when moving with the astronauts. When they arrive at the work point, they are located between the astronauts and the spacecraft. There are various obstruction conditions caused by different on-orbit positions, including no obstruction, obstruction by both the astronauts and the spacecraft, inside the spacecraft, and outside the spacecraft.

4. The thermal analysis method for uncertain heat flow of a space on-orbit maintenance power tool according to claim 1, characterized in that: The establishment of the thermal condition matrix in step 103 specifically includes: Combined with the working conditions of the electric tool's cabin exit in the sunny area and the shadowed area, a thermal analysis matrix of the electric tool based on the working mode, on-orbit shading, and cabin exit timing is established, including multiple thermal analysis conditions of the electric tool under different working modes, different on-orbit shading, and different cabin exit timing.

5. The thermal analysis method for uncertain heat flow of a space on-orbit maintenance power tool according to claim 1, characterized in that: Determining the thermal simulation input in step 104 specifically includes: Determine the thermal environment parameters of the actual spacecraft orbit where the power tool is located when it is working, including heat flux density and solar incidence angle; the thermal control of the power tool itself includes determining the basic information of thermal power consumption, temperature index and junction-to-case thermal resistance of the main heat-generating components.

6. The thermal analysis method for uncertain heat flow of a space on-orbit maintenance power tool according to claim 1, characterized in that: The thermal parameter setting in step 105 specifically includes: The thermal physical parameters and optical parameters of each component of the thermal model are designed and selected. The thermal physical parameters are the density, specific heat capacity, and thermal conductivity of the extravehicular power tool housing, motor, battery, thermal insulation component, and thermal pad material; the optical parameters are the solar absorption ratio α of the extravehicular power tool housing surface and surrounding obstructions such as spacecraft and space suit surfaces. S , infrared emissivity ε.

7. The thermal analysis method for uncertain heat flow of an on-orbit maintenance power tool for space according to claim 1, characterized in that: The thermal condition simulation analysis in step 106 is used to verify the rationality and feasibility of the thermal control solution for the power tool.

Images