Compact single-axis rotation modulation fiber-optic inertial navigation based on low-thermal-coupling compartmentalized heat dissipation structure

Abstract

The application discloses a compact single-axis rotary modulation optical fiber inertial navigation based on a low-thermal-coupling compartmentalized heat dissipation structure, comprising an optical fiber inertial navigation body, a shell, a heat-conducting compartment plate, a cylindrical heat-insulating shell and a heat dissipation groove. The shell is divided into a first compartment and a second compartment through the heat-conducting compartment plate, main heat-emitting electronic modules are arranged in the first compartment, and inertial measurement assemblies are arranged in the second compartment, so that the heat of each is respectively transmitted to the surface of the shell. The cylindrical heat-insulating shell is arranged outside the inertial measurement assemblies, the heat influence on the inertial measurement assemblies is weakened without significantly increasing the radial space, and meanwhile, the heat dissipation path of the heat of the inertial measurement assemblies is reserved. The outer surface of the shell is provided with a material-removed heat dissipation groove, which is used for enhancing the natural convection heat exchange capacity and reducing the mass of the shell. The application reconstructs the heat dissipation path of the optical fiber inertial navigation, forms a closed loop heat path for reducing the thermal coupling between the fixed heat-emitting electronic modules and the rotary inertial measurement assemblies, improves the thermal environment around the optical fiber gyroscopes and accelerometers, and takes into account the compactness, light weight and heat dissipation performance.

Description

Technical Field

[0001] This invention relates to the fields of structural design, thermal isolation design, and lightweight heat dissipation design of fiber optic gyroscope inertial navigation systems, and particularly to a compact single-axis rotation modulation fiber optic inertial navigation system based on a low thermal coupling compartment heat dissipation structure. Background Technology

[0002] Single-axis rotationally modulated fiber optic inertial navigation systems (INS) improve the long-term accuracy of navigation systems by modulating and suppressing errors in inertial devices such as fiber optic gyroscopes and accelerometers through periodic rotation of the inertial measurement unit (IMU) around a single axis. These INS typically include components such as an IMU, a rotating axis system, a drive motor, a calculation board, an IMU power module, a motor drive module, and a housing. Due to the compact overall structure and high integration of functional modules within a limited space, the fixed heat-generating electronic module and the rotating IMU share a housing, resulting in a dense distribution of internal heat sources, which can easily lead to heat concentration, intersecting heat paths, and uneven temperature fields.

[0003] The calculation board, IMU power module, and motor drive module generate heat during operation. This heat can be transferred to the inertial measurement unit (IMU) through the casing, mounting plates, supports, surface thermal radiation, and internal natural convection, creating a non-uniform temperature field near the fiber optic gyroscope and accelerometer. Since the fiber optic gyroscope and accelerometer are highly sensitive to temperature changes, this non-uniform temperature field leads to decreased zero-bias stability of the fiber optic gyroscope, reduced output stability of the accelerometer, and changes in the error parameters of the inertial devices. Furthermore, because the inertial navigation calculation continuously integrates the gyroscope angular rate and accelerometer specific force output, the temperature-induced device errors accumulate during attitude, velocity, and position calculations, significantly impacting navigation accuracy.

[0004] Existing compact single-axis rotary modulation fiber optic inertial navigation systems (INS) are typically limited by overall size, weight, and internal installation space. Their thermal control structures fall into two main categories: one lacks a dedicated heat dissipation structure on the outer casing, relying primarily on the casing's own heat conduction and natural convection on the outer surface; the other incorporates heat dissipation fins on the exterior of the casing to increase the heat exchange area between the casing and the surrounding air. For the former, due to the compact arrangement of heat-generating components such as the internal calculation board, IMU power module, and motor drive module with inertial elements like fiber optic gyroscopes and accelerometers, the lack of isolation design for the thermal coupling path between heat sources and inertial measurement components can easily lead to heat transfer from the heat-generating modules to the area where the inertial measurement components are located, resulting in increased temperatures or uneven temperature fields near the fiber optic gyroscopes and accelerometers. For the latter, while heat dissipation fins can enhance the heat exchange capacity of the casing surface, they usually require adding protruding structures on the exterior, increasing the overall size envelope and structural weight, which is detrimental to the miniaturization and lightweight design of compact single-axis rotary modulation fiber optic INS. At the same time, simply enhancing heat dissipation on the outer shell surface does not necessarily reduce the thermal coupling between the internal heat-generating electronic modules and the rotating inertial measurement unit. Heat may still be transferred to the inertial measurement unit through the partition, base plate, support components, or cabin air.

[0005] Furthermore, while existing micro- or MEMS inertial navigation systems possess certain compartmentalized or modular layouts, these structures typically serve primarily for device placement, assembly isolation, or general thermal management. The requirements for inertial measurement unit (IMU) size, heat source intensity, rotational structure constraints, and temperature stability differ from those of single-axis rotationally modulated fiber optic IMUs. In single-axis rotationally modulated fiber optic IMUs, the IMU needs to rotate with the rotational axis, and the fiber optic gyroscopes and accelerometers have high requirements for local temperature field stability. Therefore, their external thermal protection structure not only needs to reduce the thermal radiation and conduction effects of external heat-generating modules but also needs to match the rotational envelope of the IMU to avoid significantly increasing radial space occupancy or affecting rotational clearance. Simultaneously, it needs to prevent localized heat accumulation caused by enclosing and insulating the IMU.

[0006] Therefore, it is necessary to propose a novel compartmentalized heat dissipation structure to separate heat sources and extend heat paths within the inertial navigation system, while avoiding localized heat accumulation. This reduces the thermal impact of fixed heat-generating electronic modules on fiber optic gyroscopes and accelerometers, while also taking into account the requirements of rotational space utilization, heat dissipation of the inertial measurement components themselves, natural convection heat dissipation, structural strength, and overall lightweight design. Summary of the Invention

[0007] The purpose of this invention is to provide a compact single-axis rotating modulation fiber optic inertial navigation system based on a low thermal coupling compartmentalized heat dissipation structure. This invention focuses on the thermal coupling path between the fixed heat-generating electronic module and the rotating inertial measurement unit. Through the coordinated operation of the compartmentalized heat dissipation structure formed by the outer shell and heat-conducting chamber, the rotating envelope-matched cylindrical heat-insulating shell, and the material-free heat dissipation grooves, a closed-loop thermal path is constructed, connecting heat source compartmentation, thermal path extension, sensitive inertial measurement unit thermal shielding, inertial measurement unit self-conducted heat release, and external heat dissipation from the outer shell.

[0008] The compartmentalized heat dissipation structure separates the main heat-generating electronic modules, such as the motor drive module and the calculation board, from the inertial measurement unit (IMU), prioritizing the transfer of heat generated by these modules to the outer shell surface. The cylindrical heat-insulating shell, matching the rotational envelope of the IMU, reduces the impact of external heat sources on the heat conduction and radiation of the fiber optic gyroscope and accelerometer. Simultaneously, the IMU can still transfer its own heat outwards through structural paths such as the mounting base, rotating shaft system, and the shell base plate, avoiding localized heat accumulation due to simple enclosed insulation. The material-free heat dissipation grooves enhance natural convection heat transfer between the shell and the outside air, releasing heat guided to the shell through the compartmentalized structure to the external environment. Therefore, this invention solves the problem in existing compact single-axis rotating modulation fiber optic inertial navigation systems where a single heat dissipation or insulation measure cannot simultaneously address heat source isolation, IMU self-heat dissipation, rotational space constraints, and lightweight requirements.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A compact single-axis rotary modulation fiber optic inertial navigation system based on a low thermal coupling compartmentalized heat dissipation structure includes a fiber optic inertial navigation body, an outer shell, a heat-conducting compartment plate, and a cylindrical heat-insulating shell. The outer surface of the outer shell is provided with several material-free heat dissipation grooves; the heat dissipation grooves are used to increase the effective heat transfer boundary between the outer shell and the outside air.

[0011] The outer shell is a box structure; the heat-conducting chamber is a plate-shaped structure, vertically installed inside the outer shell, dividing the internal space of the outer shell into a first chamber and a second chamber; the motor drive module and the calculation board of the fiber optic inertial navigation system are located in the first chamber, and the inertial measurement unit, rotating shaft system, IF module and IMU power module of the fiber optic inertial navigation system are located in the second chamber. The inertial measurement unit is fixed to the bottom plate of the outer shell through the rotating shaft system; the heat-conducting chamber and the outer shell form a heat conduction path, and the heat generated by the calculation board and the motor drive module preferentially travels along the heat-conducting chamber to the outer shell, and is transferred outward through the heat dissipation grooves to reduce the heat radiation to the inertial measurement unit through the air inside the chamber;

[0012] The cylindrical heat-insulating shell is located in the second compartment, sleeved on the outside of the inertial measurement unit (IMU), and matches the rotational envelope formed by the IMU rotating around a single axis. A gap is left between the cylindrical heat-insulating shell and the outer shell and the heat-conducting chamber plate. The thermal resistance of the cylindrical heat-insulating shell in the radial heat transfer direction is greater than that of the outer shell, thereby reducing the heat conduction and heat radiation effects from the calculation board, motor drive module, IF module, and IMU power supply module to the IMU. At the same time, the heat generated by the IMU itself is transferred outward through the mounting base, rotating shaft system, and the bottom plate of the outer shell.

[0013] The present invention also provides a method for optimizing the size parameters of the heat sink based on the aforementioned compact single-axis rotationally modulated fiber optic inertial navigation system, comprising the following steps:

[0014] S1. The width, depth, spacing, and remaining wall thickness at the bottom of the heat sink are taken as design variables. The constraints are that the heat sink openings do not overlap, the remaining wall thickness at the bottom of the heat sink is 2.5~4.0 mm, and the total wall thickness of the outer shell is ≤4.0 mm. Multiple sets of heat sink parameter combinations are generated using the Latin hypercube sampling method.

[0015] S2. Establish a steady-state thermal simulation model, perform batch thermal simulations on different combinations of heat sink parameters, and extract the highest temperature of the inertial measurement unit and the characteristics of the surrounding temperature field; construct a training sample set based on the heat sink parameters and the extracted data.

[0016] S3. Construct an MLP neural network model, taking the width, depth, spacing and remaining wall thickness at the bottom of the heat sink as inputs, and the highest temperature and maximum thermal stress of the low thermal coupling compartment heat dissipation structure as outputs. Train the MLP neural network model using the training sample set to obtain the MLP proxy model.

[0017] S4. With minimizing the highest temperature and maximum thermal stress of the compartmentalized heat dissipation structure as the optimization objective, the parameters are optimized using a trained MLP surrogate model to obtain the heat dissipation slot parameters that enable the compartmentalized heat dissipation structure to meet the requirements of heat dissipation effect and structural performance.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] 1. This invention utilizes a heat-conducting chamber inside the outer casing to house the motor drive module and the calculation board in the first compartment, and the inertial measurement unit, rotating shaft system, IF module, and IMU power module in the second compartment, thus separating the thermal paths of the main heat-generating electronic modules from those of the inertial measurement unit. The heat-conducting chamber, together with the inner wall of the outer casing, forms a heat-conducting channel, allowing most of the heat generated by the main heat-generating electronic modules in the first compartment to be preferentially transferred to the outer casing surface via the heat-conducting chamber and the inner wall of the outer casing, and further released to the outside air through heat dissipation grooves on the outer surface of the outer casing. This compartmentalized structure not only achieves functional zoning but also increases the path length for heat transfer from the heat-generating electronic modules in the first compartment to the inertial measurement unit in the second compartment, thereby reducing its thermal impact on the fiber optic gyroscope and accelerometer.

[0020] 2. The present invention provides a cylindrical heat-insulating shell on the outside of the inertial measurement unit. The cylindrical heat-insulating shell is matched with the rotational envelope of the inertial measurement unit, which can form a heat shield structure without significantly increasing the radial space occupied by the inertial measurement unit. This not only reduces the heat generated by the main heat-generating electronic modules such as the calculation board and motor drive module on the thermal radiation and heat conduction of the fiber optic gyroscope and accelerometer, but also improves the internal space utilization of the compact single-axis rotation modulation fiber optic inertial guide.

[0021] 3. The cylindrical heat-insulating shell in this invention does not simply enclose the inertial measurement unit (IMU), but rather, while reducing the impact of external heat, it retains the structural path for heat transfer from the IMU to the outside through the mounting base, rotating shaft system, and the bottom plate of the shell. Therefore, this invention avoids the problem of heat loss or localized heat accumulation in the IMU due to simply covering it with a heat-insulating structure, achieving a balance between external heat shielding and the IMU's own heat dissipation.

[0022] 4. This invention features material-removing heat dissipation grooves on the outer surface of the casing, excluding the bottom surface. This increases the effective heat exchange boundary between the casing and the outside air, enhancing the heat exchange capacity between the casing and the outside air under natural convection conditions. Simultaneously, the heat dissipation grooves reduce the casing's mass by removing some of the casing material. Compared to an external heat dissipation fin structure, this invention eliminates the need for additional external protruding components, making it easier to maintain a compact overall shape while balancing enhanced heat dissipation and weight reduction.

[0023] 5. This invention is not a simple superposition of compartmentalization, heat insulation, and heat dissipation functions. Rather, it re-plans the thermal path of the fiber optic inertial navigation system through the aforementioned specific structure, enabling the heat-conducting chamber plate, cylindrical heat-insulating shell, and heat dissipation groove to form a closed-loop synergistic effect, reducing thermal coupling between the fixed heat-generating electronic module and the rotating inertial measurement unit. If only a compartmentalization structure is set, heat from the heat source chamber may still be transferred to the inertial measurement unit through the partition, bottom plate, or air inside the chamber; if only a cylindrical heat-insulating shell is set, it may obstruct the heat dissipation of the inertial measurement unit itself or increase the rotation space occupied; if only the outer shell heat dissipation groove is set, although it can enhance the heat dissipation of the outer shell, it cannot effectively cut off the internal thermal coupling path. This invention guides heat to the outer shell through a heat-conducting chamber with a large equivalent heat dissipation coefficient, weakens the residual heat effect through a cylindrical heat-insulating shell while retaining the heat release path of the inertial measurement unit itself, and enhances the external heat dissipation of the outer shell through a material-free heat dissipation groove. It forms a closed-loop heat path that connects heat source compartmentation, heat path extension, sensitive inertial group heat shielding, inertial group's own heat release, and external heat dissipation of the outer shell. Together, these improve the temperature field around the fiber optic gyroscope and accelerometer, reduce the adverse effects of non-uniform temperature field on the output stability of inertial devices and navigation calculation accuracy, and enable the compact single-axis rotation modulation fiber optic inertial navigation system to achieve efficient heat dissipation, stable thermal environment of inertial measurement unit, and lightweight structure in a limited space.

[0024] 6. The parameters of the heat dissipation slot of the present invention can be determined through finite element thermal simulation and structural simulation, or they can be determined through engineering design based on heat dissipation requirements, structural strength, and processing constraints. The parameter determination process preferably uses the highest temperature of the fiber optic gyroscope, the highest temperature of the accelerometer, the temperature field around the inertial measurement unit, the shell mass, and the structural strength as comprehensive evaluation objects. This ensures that heat dissipation performance, the thermal environment of the inertial measurement unit, the lightweight effect, and structural reliability are considered during the design phase, reducing the uncertainty caused by relying solely on experience in slot design. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall appearance of the present invention.

[0026] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0027] Figure 3 This is a schematic diagram of the thermal path of the present invention.

[0028] Figure 4 This is a schematic diagram of the internal compartment structure of the outer shell of the present invention.

[0029] Figure 5 This is a schematic diagram of the inertial measurement component structure of the present invention.

[0030] Figure 6 This is a schematic diagram of the cylindrical heat-insulating shell structure of the present invention.

[0031] Figure 7This is a schematic diagram showing the relative arrangement of the motor drive module, the calculation board, the inertial measurement unit, the IF module, and the IMU power supply module of the present invention.

[0032] Figure 8 This is a schematic diagram of the heat dissipation groove structure of the outer shell of the present invention.

[0033] Figure 9 This is a preferred dimension diagram of the heat dissipation groove structure of the present invention.

[0034] Figure 10 This is a flowchart illustrating the optimization process for the heat sink parameters of this invention.

[0035] Figure 11 The temperature distribution cloud map of the inertial navigation system is used for finite element thermal simulation of the compact single-axis rotation modulation fiber optic inertial navigation system of the present invention.

[0036] Figure 12 The heat flux distribution cloud map of the inertial guide is used for finite element thermal simulation of the compact single-axis rotationally modulated fiber optic inertial guide of the present invention.

[0037] Figure 13 The heat flux distribution cloud map of the cylindrical heat insulation shell is used for finite element thermal simulation of the compact single-axis rotationally modulated fiber optic inertial navigation system of the present invention.

[0038] Figure 14 Temperature distribution cloud map of the inertial measurement unit for finite element thermal simulation of the compact single-axis rotationally modulated fiber optic inertial navigation system of the present invention.

[0039] Figure 15 The image shows the air velocity distribution cloud map in the top view section for finite element thermal simulation of the compact single-axis rotationally modulated fiber optic inertial navigation system of the present invention.

[0040] Figure 16 This is a cloud map showing the overall air velocity distribution of the compact single-axis rotationally modulated fiber optic inertial navigation system for finite element thermal simulation of the present invention.

[0041] In the diagram: 1. Outer shell; 2. Rotating axis system; 3. Inertial measurement unit; 4. Cylindrical heat-insulating shell; 5. Solver board; 6. IF module; 7. IMU power module; 8. Motor drive module; 9. Heat-conducting chamber; 10. Heat sink; 31. X-axis fiber optic gyroscope; 32. X-axis accelerometer; 33. Y-axis fiber optic gyroscope; 34. Y-axis accelerometer; 35. Z-axis fiber optic gyroscope; and 36. Z-axis accelerometer. Detailed Implementation

[0042] The specific embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0043] like Figure 2As shown, this embodiment provides a compact single-axis rotary modulation fiber optic inertial navigation system with a low thermal coupling compartmentalized heat dissipation structure, including a fiber optic inertial navigation system body and a low thermal coupling compartmentalized heat dissipation structure. The fiber optic inertial navigation system body includes an inertial measurement unit 3, a rotating axis system 2, a calculation board 5, a motor drive module 8, an IF module 6, and an IMU power supply module 7. Figure 5 As shown, the inertial measurement unit 3 includes a fiber optic gyroscope, an accelerometer, a mounting base, and a connecting structure. The fiber optic gyroscope includes an X-axis fiber optic gyroscope 31, a Y-axis fiber optic gyroscope 33, and a Z-axis fiber optic gyroscope 35. The accelerometer includes an X-axis accelerometer 32, a Y-axis accelerometer 34, and a Z-axis accelerometer 36. Both the fiber optic gyroscope and the accelerometer are mounted on the mounting base via the connecting structure. The bottom of the mounting base is coaxially connected to the rotation axis system 2 and can rotate with the rotation axis system 2 around a single axis to achieve single-axis rotation modulation function.

[0044] like Figure 1 , Figure 2 , Figure 4 and Figure 7 As shown, the low thermal coupling compartment heat dissipation structure provided by the present invention includes an outer shell 1, a heat-conducting compartment plate 9 and a cylindrical heat-insulating shell 4, and the outer surface of the outer shell 1 is provided with heat dissipation grooves 10.

[0045] The outer shell 1 has a cubic or near-cubic structure and can be either a one-piece or a split structure. In a split embodiment, the outer shell 1 includes a lower shell and an upper cover. The lower shell includes a base plate and a sidewall extending upward from the base plate. The upper cover is positioned above the lower shell and connected to it to form an internal installation space. The upper cover and the lower shell can be connected by screws, locating pins, or snap-fit ​​connections. The interior of the outer shell 1 forms an installation space for mounting the fiber optic inertial navigation system. A heat-conducting chamber plate 9 is vertically installed inside the outer shell 1 via heat-conducting connectors. Its upper and lower ends are fixed to the top and bottom plates of the outer shell 1, respectively, dividing the internal space of the outer shell 1 into a first chamber and a second chamber. The motor drive module 8 and the calculation board 5 are the main heat-generating electronic modules and are located on the inner wall of the first chamber. The inertial measurement unit 3, the rotating shaft system 2, the IF module 6, and the IMU power module 7 are located in the second chamber. The inertial measurement unit 3 is fixed to the bottom plate of the outer shell 1 in the second chamber via the rotating shaft system 2. To ensure that the heat-conducting chamber 9 and the outer shell 1 form an effective heat-conducting channel, the heat-conducting chamber 9 is made of aluminum alloy or copper alloy with a wall thickness of 1.0 mm-3.0 mm; the outer shell 1 is made of aluminum alloy or magnesium alloy with a wall thickness of 2.5 mm-4.0 mm.

[0046] Through the aforementioned compartmentalized arrangement, the motor drive module 8 and the calculation board 5 in the first compartment are spatially and thermally isolated from the inertial measurement unit 3 in the second compartment. The heat-conducting plate 9 serves two purposes: firstly, it separates the different functional modules within the outer shell 1; secondly, it forms a heat-conducting channel together with the inner wall and bottom plate of the outer shell 1, allowing heat generated by the main heat-generating electronic modules in the first compartment to be preferentially transferred directly to the surface of the outer shell 1 via the outer shell 1 or via the heat-conducting plate 9 and the outer shell 1. Simultaneously, the heat-conducting plate 9, located between the first and second compartments, increases the path length for heat transfer from the main heat-generating electronic modules in the first compartment to the inertial measurement unit 3 in the second compartment, and reduces the degree of direct coupling between the two compartments through airflow and surface heat radiation. Reducing the impact of the main heat-generating electronic modules on the fiber optic gyroscope and accelerometer through heat conduction and radiation is beneficial for improving the temperature environment near the inertial measurement unit 3. The rotating shaft system 2, IF module 6 and IMU power module 7 are arranged in the same compartment as the inertial measurement unit 3, which can shorten the inertial measurement signal transmission path and power supply connection path, and facilitate the signal connection and power supply connection of the inertial measurement unit 3, thereby taking into account functional zoning, heat source isolation and compact layout.

[0047] like Figure 6 As shown, a cylindrical heat-insulating shell 4 is fitted over the outside of the inertial measurement unit 3, with a gap between its top and the outer shell 1. The cylindrical heat-insulating shell 4 can cover or partially cover the outside of the inertial measurement unit 3 and match the rotational envelope formed by the inertial measurement unit 3 around its rotation axis. The bottom of the cylindrical heat-insulating shell 4 has a wiring opening and an installation clearance opening for the signal lines and power supply lines of the inertial measurement unit 3 to pass through. The covering refers to the cylindrical heat-insulating shell 4 covering the top and circumferential sides of the inertial measurement unit 3, and the partial covering refers to the cylindrical heat-insulating shell 4 only covering the circumferential sides of the inertial measurement unit 3. This embodiment adopts the covering form. The thermal resistance of the cylindrical heat-insulating shell 4 is greater than that of the outer shell 1. To achieve this, the cylindrical heat-insulating shell 4 is made of PEEK, PPS or G10 composite material with a wall thickness of 0.8 mm-2.5 mm. The cylindrical heat-insulating shell 4 can form a thermal shielding structure without significantly increasing the radial space occupied by the inertial measurement unit 3, thereby creating spatial and thermal path isolation between the inertial measurement unit 3 and secondary heat-generating electronic modules such as the IF module 6 and the IMU power supply module 7, and further reducing the thermal impact of the heat generated by the motor drive module 8 and the calculation board 5 in the first cabin on the fiber optic gyroscope and accelerometer.

[0048] In one embodiment, the cylindrical heat-insulating shell 4 is a cylindrical or near-cylindrical structure. In another embodiment, the cylindrical heat-insulating shell 4 is a curved shell structure adapted to the rotational envelope of the inertial measurement unit 3. The cylindrical heat-insulating shell 4 can be connected to the mounting base of the rotating shaft system 2 or the inertial measurement unit 3 via a low thermal conductivity connector, or an air insulation gap can be formed between it and the inertial measurement unit 3 to further reduce heat transfer along the structural connection path.

[0049] It should be noted that the cylindrical heat-insulating shell 4 is not intended to completely enclose the inertial measurement unit 3, nor does it prevent the inertial measurement unit 3 from transferring its own heat outwards. The heat generated by the inertial measurement unit 3 can be transferred outwards sequentially through the mounting base, the rotating shaft system 2, and the bottom plate of the outer shell 1. The cylindrical heat-insulating shell 4 is mainly used to reduce the effects of heat radiation and heat conduction from the motor drive module 8 in the first cabin, the calculation board 5, and other heat-generating modules in the second cabin. In this way, this embodiment can protect the fiber optic gyroscope and accelerometer from external thermal disturbances while avoiding localized heat accumulation in the inertial measurement unit 3 due to simple enclosure.

[0050] like Figure 8 As shown, Figure 8 Figure (a) is a top view. Figure 8 Figure (b) is a cross-sectional view of the outer casing 1 taken along a horizontal plane and a partially enlarged view thereof. The heat dissipation grooves 10 are evenly distributed on the outer surface of the outer casing 1, excluding the bottom surface, and preferably on the top and sides of the outer casing 1. The heat dissipation grooves 10 are used to increase the effective heat exchange boundary between the outer casing 1 and the outside air, enhancing the heat exchange capacity between the outer casing 1 and the outside air under natural convection conditions. The bottom surface of the outer casing 1 has few or no heat dissipation grooves 10 to maintain the integrity of the bottom mounting, support, or assembly area.

[0051] The heat dissipation groove 10 is a material-free groove structure formed on the outer surface of the outer shell 1. Compared with external heat dissipation fins, the heat dissipation groove 10 does not require additional protrusions on the outside of the outer shell 1, thus not significantly increasing the overall shape envelope or introducing additional mass, which is beneficial for the miniaturization and lightweight design of the compact single-axis rotation modulation fiber optic inertial navigation system. The heat dissipation groove 10 is not an isolated heat dissipation measure for the outer shell 1, but is used in conjunction with the heat-conducting plate 9 as the external exhaust end of the compartment heat path. The heat-conducting plate 9 preferentially transfers the heat generated by the main heat-generating electronic modules in the first compartment to the surface of the outer shell 1. The heat dissipation groove 10 further enhances the natural convection heat transfer capacity of the surface of the outer shell 1, making it easier for heat to be released to the external environment, rather than continuing to be transferred to the inertial measurement unit 3 through the cabin air, the heat-conducting plate 9, or the support structure.

[0052] The heat dissipation groove 10 can be a strip-shaped groove extending along the height or length direction of the outer shell 1, or an array of grooves distributed along the side wall or top surface of the outer shell 1, or a composite groove distributed in multiple directions. The groove width, groove depth, groove length, groove spacing, number of grooves, and remaining wall thickness of the outer shell 1 can be determined according to the structural dimensions of the outer shell 1, natural convection heat dissipation requirements, lightweight requirements, processing technology requirements, and structural strength requirements.

[0053] like Figure 10As shown, the dimensional parameters of the heat sink 10 can be determined through finite element thermal simulation and structural simulation. In one embodiment, the following steps are included:

[0054] S1. Determine the design variables and constraints of the heat dissipation slot 10, such as the slot width, slot depth, slot spacing, and remaining wall thickness of the outer shell 1. The constraints include, but are not limited to, the slot openings of the heat dissipation slot 10 not overlapping, the remaining wall thickness of the outer shell 1 being 2.5~4.0mm, and the total wall thickness of the outer shell 1 being ≤4.0mm. Use the Latin hypercube sampling method to generate multiple sets of heat dissipation slot 10 parameter combinations. In this embodiment, 45 sets of heat dissipation slot 10 parameter combinations are generated.

[0055] S2. Establish a steady-state thermal simulation model, perform batch thermal simulations on different combinations of 10 parameters of heat sinks, and extract the highest temperature of fiber optic gyroscope and accelerometer as well as the temperature field characteristics around inertial measurement component 3.

[0056] S3. A training sample set is constructed based on the parameters of the heat sink 10 and the highest temperatures of the corresponding fiber optic gyroscope and accelerometer, as well as the temperature field characteristics around the inertial measurement component 3.

[0057] S4. Construct an MLP neural network model, using the slot width w, slot depth d, slot spacing p, and remaining wall thickness t at the bottom of the heat sink 10 as parameters. r Using the highest temperature Tg,max and the maximum thermal stress Ta,max of the compartmentalized heat dissipation structure as inputs, and the MLP neural network model as outputs, the MLP surrogate model is trained using the training sample set to obtain the MLP surrogate model.

[0058] S5. With minimizing the maximum temperature Tg,max and maximum thermal stress Ta,max of the compartmentalized heat dissipation structure as the optimization objective, the optimal parameters for the heat dissipation slot 10 are obtained through parameter optimization using a trained MLP surrogate model. The heat dissipation effect and structural performance are then verified through thermal and mechanical simulations. Maximum temperature, maximum stress, and maximum deformation can be set as verification indicators. If the verification results meet the cooling and mechanical requirements, the optimal parameters for the heat dissipation slot 10 are output as the optimal size parameters for the heat dissipation slot 10. If the cooling and mechanical requirements are not met, additional samples are added and the surrogate model is retrained until the parameters for the heat dissipation slot 10 that meet the cooling and mechanical requirements are obtained.

[0059] The above-described optimization process for the parameters of the heat sink 10 is used to illustrate a preferred method for determining the parameters, and does not limit the parameters of the heat sink 10 to be obtained through this method. This optimization process is not solely aimed at reducing the temperature of the outer shell 1, but rather, with regard to the low thermal coupling compartmentalized heat dissipation structure described in this invention, it determines the parameters of the heat sink 10 by taking into account the thermal environment stability of the fiber optic gyroscope and accelerometer, the natural convection heat dissipation capacity of the outer shell 1, and the mass and structural strength of the outer shell 1.

[0060] Subject to the above requirements, the dimensions of the heat dissipation groove 10 can be selected as follows: groove width 3.0 mm-5.0 mm, groove depth 0.5 mm-1.2 mm, and groove spacing 5.0 mm-8.0 mm. For example... Figure 9 As shown, in a preferred embodiment, the total wall thickness of the outer shell 1 is 3.7 mm, the depth of the heat dissipation groove 10 is 0.8 mm, the groove width is 3.8 mm, the arrangement spacing between adjacent heat dissipation grooves 10 is 6.1 mm, and the remaining wall thickness at the bottom of the heat dissipation groove 10 is 2.9 mm. These dimensional parameters can increase the effective heat exchange boundary between the outer shell 1 and the outside air while ensuring the necessary structural strength of the outer shell 1, and reduce the mass of the outer shell 1 by removing some shell material.

[0061] The thermal path of the low thermal coupling compartment heat dissipation structure provided by this invention is as follows: Figure 3 As shown, this invention alters the heat transfer path within the inertial navigation system through the combined use of a heat-conducting chamber 9, a cylindrical heat-insulating shell 4, and heat dissipation grooves 10. The heat-conducting chamber 9, positioned between the first and second chambers, spatially separates the main heat-generating electronic modules, such as the motor drive module 8 and the calculation board 5, from the inertial measurement unit 3. Furthermore, it forms a heat-conducting channel with the inner wall and bottom plate of the outer shell 1. This allows most of the heat generated by the main heat-generating electronic modules in the first chamber to preferentially transfer to the surface of the outer shell 1 via the heat-conducting chamber 9, the inner wall, and the bottom plate, and then to the outside air through the heat dissipation grooves 10 on the outer surface of the outer shell 1 via natural convection heat exchange, thereby reducing heat diffusion to the area where the inertial measurement unit 3 is located in the second chamber. The heat dissipation grooves 10, distributed on the outer surface of the outer shell 1, increase the effective heat exchange boundary between the outer shell 1 and the outside air, enhancing natural convection heat exchange capacity while simultaneously improving heat dissipation efficiency and reducing the overall weight of the system. The cylindrical heat-insulating shell 4 is disposed outside the inertial measurement unit 3 to reduce the thermal radiation impact of the heating elements in the first and second chambers on the inertial measurement unit 3 and to avoid the formation of solid thermal bridges. At the same time, the heat generated by the inertial measurement unit 3 inside can still be dissipated to the external environment through the mounting base, the rotating shaft system 2, and the bottom plate of the outer shell 1. Thus, the heat-conducting chamber plate 9, the cylindrical heat-insulating shell 4, and the heat dissipation groove 10 are not independent heat dissipation or heat insulation components, but are arranged sequentially in the thermal path to reduce the thermal coupling between the fixed heating electronic module and the rotating inertial measurement unit 3.

[0062] To further illustrate the synergistic effect of the heat-conducting chamber plate 9, the cylindrical heat-insulating shell 4, and the heat dissipation groove 10 in the low thermal coupling compartment heat dissipation structure, the heat transfer process between the main heat-generating electronic modules and the inertial measurement unit 3 in the first compartment can be equivalent to a multi-path thermal network model. Let the total heat generation power of the main heat-generating electronic modules such as the motor drive module 8 and the calculation board 5 in the first compartment be... The inertial measurement unit 3 itself generates heat with a power of [missing information]. The ambient temperature is The equivalent temperature of the main heat-generating electronic modules in the first compartment is The equivalent temperature of inertial measurement unit 3 is The equivalent temperature of the outer surface of shell 1 is .

[0063] The heat generated by the main heat-generating electronic modules in the first compartment is transferred through two main paths: one is through the heat-conducting plate 9, the inner wall of the outer shell 1, and / or the bottom plate of the outer shell 1 to the outer surface of the outer shell 1, and then through natural convection heat exchange with the outside air via the heat dissipation slots 10; the other is a thermal coupling path that transfers heat towards the inertial measurement unit 3 in the second compartment. The total heat generation power of the main heat-generating electronic modules in the first compartment is... The heat distribution along the two paths can be represented as:

[0064]

[0065] in, The heat dissipated to the outside by the main heat-generating electronic modules in the first compartment through the heat-conducting plate 9, the outer shell 1, and the heat dissipation groove 10. The heat transferred from the main heat-generating electronic modules of the first compartment to the inertial measurement unit 3. This refers to heat transferred via connectors, cabin air turbulence, and other secondary paths. The equivalent thermal resistance of the exhaust path is established below. Equivalent thermal resistance of thermal coupling path This further explains how the heat-conducting chamber 9, the cylindrical heat-insulating shell 4, and the heat dissipation groove 10 change the above-mentioned heat distribution relationship.

[0066] The equivalent thermal resistance of the main heat-generating electronic module in the first compartment to the outer surface of the outer shell 1 through the exhaust path is... It can be represented as:

[0067]

[0068] in, The contact thermal resistance between the main heat-generating electronic module and the heat-conducting chamber 9 or the outer shell 1, The thermal resistance corresponding to the heat-conducting chamber 9, The thermal resistance of the inner wall of the outer casing 1 and / or the bottom plate of the outer casing 1. The natural convection thermal resistance between the outer surface of the outer casing 1 and the outside air.

[0069] Equivalent thermal resistance of heat-conducting chamber 9 It can be represented as:

[0070]

[0071] in, This is the equivalent thermal conductivity length of the thermally conductive chamber 9. The thermal conductivity of material 9 in the heat-conducting chamber is... This is the equivalent thermal conductivity area between the heat-conducting chamber 9 and the main heat-generating electronic module or the outer shell 1. As can be seen from the above formula, the heat-conducting chamber 9 is not simply used for heat insulation, but rather, by using materials with good thermal conductivity, increasing the effective contact area, and forming a thermally conductive connection with the bottom plate or inner wall of the outer shell 1, it reduces the outward thermal resistance from the main heat-generating electronic module of the first chamber to the outer surface of the outer shell 1, allowing heat to be preferentially discharged outward along the heat-conducting chamber 9 and the outer shell 1.

[0072] The heat transferred from the heat-generating electronic modules in the first and second compartments to the inertial measurement unit 3 can be considered as an equivalent thermal coupling path. The equivalent thermal resistance of this path... It can be represented as:

[0073]

[0074] in, The equivalent thermal resistance is formed by the air gap and spatial distance within the outer casing 1. The thermal resistance of the cylindrical insulation shell 4 is... The equivalent radiative thermal resistance of the main heat-generating electronic module of the first compartment, the heat-conducting plate 9, and the heat-generating module in the second compartment to the inertial measurement unit 3.

[0075] Thermal resistance of cylindrical heat insulation shell 4 It can be represented as:

[0076]

[0077] in, The equivalent thickness of the cylindrical heat insulation shell 4 is... The thermal conductivity of the material of the cylindrical insulation shell 4 is given. This is the equivalent heat-receiving area of ​​the cylindrical heat-insulating shell 4.

[0078] When considering the impact of thermal radiation, the equivalent radiative thermal resistance of the main heat-generating electronic module in the first compartment, the heat-conducting plate 9, and the heat-generating module in the second compartment to the inertial measurement unit 3 is... It can be represented as:

[0079]

[0080] in, Let be the blackbody radiation constant. For equivalent emissivity, The effective radiation angle coefficient of the inertial measurement unit 3 is the coefficient of radiation from the main heat-generating electronic module of the first compartment, the heat-conducting plate 9, and the heat-generating module in the second compartment. This is the equivalent radiation area. The average absolute temperature is the temperature between the main heat-generating electronic module in the first compartment, the heat-conducting plate 9, and the heat-generating module in the second compartment and the inertial measurement unit 3.

[0081] After the cylindrical heat-insulating shell 4 forms a covering thermal shield on the circumferential sides and top of the inertial measurement unit 3, it can reduce the effective radiation angle coefficient of the main heat-generating electronic module in the first compartment, the heat-conducting plate 9, and the heat-generating module in the second compartment to the inertial measurement unit 3. Meanwhile, due to the low thermal conductivity of the material of the cylindrical heat insulation shell 4, the thermal coupling path can be increased. Therefore, the cylindrical heat-insulating shell 4 can reduce the thermal impact of the heating modules in the first and second compartments on the inertial measurement unit 3 from both heat conduction and heat radiation aspects.

[0082] After the heat dissipation grooves 10 are provided on the outer surface of the outer casing 1, the natural convection thermal resistance between the outer casing 1 and the outside air is reduced. It can be represented as:

[0083]

[0084] in, Let be the equivalent natural convection heat transfer coefficient of the outer surface of shell 1. The effective heat transfer area is the outer surface of the outer casing 1. For an outer casing 1 with multiple rectangular heat dissipation slots 10, the effective heat transfer area is... It can be represented as:

[0085]

[0086] in, This represents the heat exchange area of ​​the outer surface of the outer casing 1 when the heat dissipation slot 10 is not provided. The number of heat dissipation slots is 10. For the first Each heat dissipation slot has a width of 10. For the first Each heat dissipation slot has a depth of 10. For the first Each heat dissipation slot is 10mm long. This is the effective heat transfer correction factor for heat sink 10.

[0087] After removing material from the heat sink 10, the mass reduction of the outer casing 1 It can be represented as:

[0088]

[0089] in, Let be the material density of the outer shell 1. Therefore, the heat dissipation groove 10 can, on the one hand, increase the effective heat exchange area of ​​the outer surface of the outer shell 1 and reduce the natural convection thermal resistance; on the other hand, it can reduce the amount of material used in the outer shell 1 and reduce the overall weight, thus balancing the requirements of natural convection heat dissipation and lightweight design.

[0090] Since the cylindrical heat-insulating shell 4 is not a completely sealed structure, and the inertial measurement unit 3 is still connected to the rotating shaft system 2 via the mounting base, the heat generated by the inertial measurement unit 3 itself can be transferred to the outer surface of the shell 1 through the mounting base, the rotating shaft system 2, and the bottom plate of the shell 1. The equivalent thermal resistance of this heat dissipation path... It can be represented as:

[0091]

[0092] in, The thermal resistance corresponding to the mounting base of inertial measurement unit 3. The thermal resistance is the resistance of the rotating shaft system 2. The equivalent temperature rise of inertial measurement unit 3 can be expressed as:

[0093]

[0094] in, This is the equivalent temperature rise of the inertial measurement unit 3 relative to the external environment. The power generated by the inertial measurement unit 3 itself. This is the coupled heat transferred from the main heat-generating electronic module of the first compartment to the inertial measurement unit 3.

[0095] This embodiment reduces heat loss through the cylindrical heat insulation shell 4. At the same time, the structural path for the inertial measurement unit 3 to dissipate heat outward through the mounting base, rotating shaft system 2 and the bottom plate of the outer shell 1 is retained. Therefore, the thermal impact of external heat sources on the inertial measurement unit 3 can be reduced, and local heat accumulation in the inertial measurement unit 3 due to the cylindrical heat insulation shell 4 can be avoided.

[0096] According to the aforementioned thermal network model, the heat generated by the main heat-generating electronic modules in the first compartment is distributed between the exhaust path and the thermal coupling path. Ignoring secondary heat transfer paths, the thermal coupling ratio transferred from the main heat-generating electronic modules in the first compartment to the inertial measurement unit 3 is... It can be represented as:

[0097]

[0098] Since heat tends to be transferred along paths with lower thermal resistance, under simplified conditions with similar equivalent temperature differences, the thermal coupling ratio... This can be further expressed as:

[0099]

[0100] Further define the evaluation factors for low thermal coupling :

[0101]

[0102] Then the thermal coupling ratio It can be represented as:

[0103]

[0104] From the above formula, it can be seen that when reduce, When increased, the low thermal coupling evaluation factor Increase the thermal coupling ratio reduce.

[0105] In this embodiment, the heat-conducting chamber plate 9 and the outer shell 1 form a heat-conducting channel, thereby reducing the heat dissipation from the main heat-generating electronic modules of the first chamber to the outer surface of the outer shell 1. The heat sink 10 increases the effective heat exchange area on the outer surface of the outer casing 1, further reducing... This will further reduce The increased air gap between the cylindrical heat-insulating shell 4 and the heat-conducting plate 9 increases the heat transfer from the first chamber to the inertial measurement unit 3. Therefore, the heat-conducting chamber 9, the cylindrical heat-insulating shell 4, and the heat dissipation groove 10 work together to... Enlarge This reduces thermal coupling between the fixed-heating electronic module and the rotating inertial measurement unit 3.

[0106] To verify the thermal design effectiveness of the low thermal coupling compartmentalized heat dissipation structure described in this embodiment, a finite element thermal simulation analysis was performed on the compact single-axis rotating modulation fiber optic inertial navigation system (INS) in this embodiment. The simulation object is the overall structure of the single-axis rotating modulation fiber optic INS, including components such as the outer shell 1, heat-conducting compartment 9, cylindrical heat-insulating shell 4, rotating shaft system 2, inertial measurement unit 3, calculation board 5, IF module 6, IMU power supply module 7, and motor drive module 8. The simulation condition is a steady-state thermal equilibrium condition at room temperature, with the ambient temperature set to 25 ℃. Natural convection heat transfer is used between the outer surface of the outer shell 1 and the outside air. All structural components are treated as solid-contact thermally conductive, and screw connections or structural fastening areas are considered to have good contact.

[0107] like Figure 11 and Figure 12 As shown, Figure 11 This is a cloud map showing the overall temperature distribution of the machine in this embodiment. Figure 12This is a heat flux distribution cloud diagram of the entire unit in this embodiment. Simulation results show that under steady-state operating conditions, the highest temperature of the entire unit is 42.777 ℃, and the lowest temperature is 28.602 ℃. The temperature distribution of the entire unit forms a continuous temperature gradient along the height direction of the outer shell 1 and the side wall area, indicating that the internal heat can be transferred from the main heat-generating electronic modules through the heat-conducting chamber 9, the inner wall of the outer shell 1, and / or the bottom plate of the outer shell 1 to the surface of the outer shell 1. The heat flux distribution of the entire unit further shows that there is a relatively continuous heat flux distribution in the side wall of the outer shell 1, the bottom connection area of ​​the outer shell 1, and near the heat dissipation slot 10, indicating that the heat generated by the main heat-generating electronic modules in the first compartment is not mainly concentrated in the area where the inertial measurement component 3 is located, but is guided to the side wall and bottom structure of the outer shell 1, and further released to the outside air through the outer surface of the outer shell 1. It can be seen that the heat-conducting channel formed by the heat-conducting chamber 9 and the outer shell 1 can effectively undertake the front-end heat transfer function of the heat exhaust path of the first compartment.

[0108] like Figure 13 As shown, Figure 13 This is a heat flux distribution cloud map of the area where the cylindrical heat-insulating shell 4 is located in this embodiment. This map is mainly used to observe the structural heat conduction path of the inertial measurement unit 3 within the area covered by the cylindrical heat-insulating shell 4. Simulation results show that the heat generated by the inertial measurement unit 3 itself can be transferred downwards through the mounting base, the rotating shaft system 2, and its connection path with the bottom plate of the outer shell 1, indicating that the cylindrical heat-insulating shell 4 does not block the heat release path of the inertial measurement unit 3 itself. Simultaneously, the cylindrical heat-insulating shell 4 forms a covering thermal shield for the circumferential sides and top of the inertial measurement unit 3, which can reduce the thermal radiation and heat conduction effects of external heat-generating modules on the fiber optic gyroscope and accelerometer. Therefore, this embodiment balances external thermal influence shielding and the downward transfer of heat from the inertial measurement unit 3 itself.

[0109] like Figure 14 As shown, Figure 14 This is a temperature distribution cloud map of the inertial measurement unit 3 in this embodiment. Simulation results show that the highest temperature of the inertial measurement unit 3 is 37.315 ℃, the lowest temperature is 35.381 ℃, and the temperature difference is 1.934 ℃. Further analysis shows that the highest temperature of the fiber optic gyroscope is 37.315 ℃, the lowest temperature is 36.352 ℃, and the temperature difference is 0.963 ℃; the highest temperature of the accelerometer is 37.255 ℃, the lowest temperature is 36.634 ℃, and the temperature difference is 0.621 ℃. These results indicate that even when the solver board 5, motor drive module 8, IF module 6, IMU power module 7, motor stator, fiber optic gyroscope, and accelerometer are all operating and generating heat, no significant localized overheating occurs in the area of ​​the inertial measurement unit 3, and the temperature distribution near the fiber optic gyroscope and accelerometer is relatively concentrated. The results show that the cylindrical heat-insulating shell 4 can reduce the thermal impact of the external heating module on the inertial measurement unit 3, while the mounting base, rotating shaft system 2 and the bottom plate of the shell 1 can still provide the inertial measurement unit 3 with its own heat release path.

[0110] like Figure 15 As shown, Figure 15 This is a top-view cross-sectional airflow velocity distribution cloud diagram of this embodiment. Simulation results show that relatively independent airflow areas are formed on both sides of the heat-conducting chamber 9. No obvious through-type high-speed flow channel appears between the first and second chambers, indicating that the heat-conducting chamber 9 can spatially separate the first and second chambers, reducing the degree of direct heat exchange between the two chambers through the air inside the chambers. At the same time, after the heat-conducting chamber 9 is connected to the outer shell 1, it forms a structural heat conduction path, allowing the heat generated by the main heat-generating electronic modules such as the solver board 5 and the motor drive module 8 in the first chamber to be preferentially transferred outward through the heat-conducting chamber 9 and the outer shell 1, rather than directly diffused to the area where the inertial measurement component 3 is located in the second chamber. It can be seen that the heat-conducting chamber 9 in this embodiment simultaneously plays the roles of functional compartmentation, thermal environment separation, and heat outward conduction, which helps to maintain the relative independence of the thermal environment of the first and second chambers. The airflow velocity near the heat dissipation groove 10 on the side wall of the outer shell 1 is relatively high in the figure, which also indicates that the heat dissipation groove 10 can serve as the end of the heat exhaust path of the outer shell 1, further promoting natural convection heat transfer on the surface of the outer shell 1.

[0111] like Figure 16 As shown, Figure 16 This is a cloud map showing the overall airflow velocity distribution of the inertial navigation system in this embodiment. Simulation results show that under natural convection conditions, the airflow velocity is relatively high near the sidewalls and top heat dissipation slots 10 of the outer casing 1, and a noticeable airflow band is formed around the area of ​​the heat dissipation slots 10. This result indicates that the heat dissipation slots 10 can increase the effective heat transfer boundary between the outer casing 1 and the outside air, and promote the release of heat from the surface of the outer casing 1 to the outside air under natural convection conditions. Since the heat dissipation slots 10 are material-free groove structures formed on the outer surface of the outer casing 1, they enhance the natural convection heat transfer capacity of the outer casing 1 without requiring additional external protruding parts, thus achieving a balance between heat dissipation efficiency, compact shape, and lightweight casing.

[0112] Based on the simulation results above, it can be seen that in this embodiment, the heat-conducting chamber 9, the cylindrical heat-insulating shell 4, and the heat dissipation groove 10 form a continuous fit in the thermal path. The heat-conducting chamber 9 preferentially directs the heat generated by the main heat-generating electronic modules such as the first chamber's calculation board 5 and the motor drive module 8 to the side wall of the outer shell 1, the bottom plate of the outer shell 1, and the outer surface where the heat dissipation groove 10 is located. The cylindrical heat-insulating shell 4 forms a thermal shield for the circumferential sides and top of the inertial measurement component 3, and retains the structural path for the inertial measurement component 3 to transfer heat outward through the mounting base, the rotating shaft system 2, and the bottom plate of the outer shell 1. The heat dissipation groove 10 serves as the end of the heat exhaust path of the outer shell 1, enhancing the natural convection heat transfer between the outer shell 1 and the outside air. Therefore, this embodiment can reduce the thermal coupling between the fixed heat-generating electronic modules and the rotating inertial measurement component 3, improve the thermal environment around the fiber optic gyroscope and accelerometer, and take into account the requirements of compactness, lightweighting, and natural convection heat dissipation.

[0113] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A compact single-axis rotationally modulated fiber optic inertial navigation system based on a low thermal coupling compartmentalized heat dissipation structure, characterized in that, It includes a fiber optic inertial navigation body, an outer shell, a heat-conducting chamber, and a cylindrical heat-insulating shell. The outer surface of the outer shell is provided with several material-removing heat dissipation grooves; the heat dissipation grooves are used to increase the effective heat exchange boundary between the outer shell and the outside air. The outer shell is a box structure; the heat-conducting chamber is a plate-shaped structure, vertically installed inside the outer shell, dividing the internal space of the outer shell into a first chamber and a second chamber; the motor drive module and the calculation board of the fiber optic inertial navigation system are located on the inner wall of the first chamber, and the inertial measurement unit, rotating axis, IF module and IMU power module of the fiber optic inertial navigation system are located in the second chamber. The inertial measurement unit is fixed to the bottom plate of the outer shell through the rotating axis; the heat-conducting chamber and the outer shell form a heat conduction path, and the heat generated by the calculation board and the motor drive module travels along the inner wall of the first chamber to the outer surface of the outer shell, and is transferred outward through the heat dissipation grooves; The cylindrical heat-insulating shell is located in the second compartment and is fitted outside the inertial measurement unit. There is a gap between the cylindrical heat-insulating shell and the outer shell and the heat-conducting chamber plate. The thermal resistance of the cylindrical heat-insulating shell in the radial heat transfer direction is greater than that of the outer shell. At the same time, the heat generated by the inertial measurement unit itself is transferred outward through the rotating shaft system and the bottom plate of the outer shell.

2. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 1, characterized in that, The motor drive module, IF module, and IMU power module of the fiber optic inertial navigation system are all installed on the inner wall of the outer shell, and the calculation board is installed on the heat-conducting chamber plate.

3. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 1, characterized in that, The outer shell is made of aluminum alloy or magnesium alloy with a wall thickness of 2.5 mm-4.0 mm; the heat-conducting chamber is made of aluminum alloy or copper alloy with a wall thickness of 1.0 mm-3.0 mm; the cylindrical heat-insulating shell is made of PEEK, PPS or G10 composite material with a wall thickness of 0.8 mm-2.5 mm.

4. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 1, characterized in that, The cylindrical heat insulation shell is a curved shell structure adapted to the rotational envelope of the inertial measurement unit, and covers or partially covers the outside of the inertial measurement unit; the covering refers to the cylindrical heat insulation shell covering the top and circumferential sides of the inertial measurement unit, and the partial covering refers to the cylindrical heat insulation shell covering only the circumferential sides of the inertial measurement unit.

5. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 1, characterized in that, A gap is left between the cylindrical heat-insulating shell and the inertial measurement component to form an air-insulating gap.

6. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 1, characterized in that, The heat dissipation grooves are distributed on the top and side surfaces of the housing, and are arranged uniformly or in an array on the top and side surfaces.

7. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 1, characterized in that, The heat dissipation grooves extend along the height or length of the outer casing, or are distributed in multiple directions.

8. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 1, characterized in that, The depth of the heat dissipation groove is less than the total wall thickness of the outer shell, and the remaining wall thickness at the bottom of the heat dissipation groove meets the structural strength requirements of the outer shell.

9. The compact single-axis rotationally modulated fiber optic inertial navigation system according to claim 8, characterized in that, The width of the heat dissipation groove is 3.0 mm to 5.0 mm, the depth is 0.5 mm to 1.2 mm, and the spacing between the grooves is 5.0 mm to 8.0 mm.

10. A method for optimizing the size parameters of a heat sink in a compact single-axis rotationally modulated fiber optic inertial navigation system according to any one of claims 1-9, characterized in that, Includes the following steps: S1. The width, depth, spacing and remaining wall thickness at the bottom of the heat sink are taken as design variables. The constraints are that the heat sink openings do not overlap, the remaining wall thickness at the bottom of the heat sink is 2.5 to 4.0 mm, and the total wall thickness of the outer shell is ≤4.0 mm. Multiple sets of heat sink parameter combinations are generated using the Latin hypercube sampling method. S2. Establish a steady-state thermal simulation model, perform batch thermal simulations on different combinations of heat sink parameters, and extract the highest temperature of the inertial measurement unit and the characteristics of the surrounding temperature field. A training sample set was constructed based on the parameters of the heat sink and the extracted data. S3. Construct an MLP neural network model, taking the width, depth, spacing and remaining wall thickness at the bottom of the heat sink as inputs, and the highest temperature and maximum thermal stress of the low thermal coupling compartment heat dissipation structure as outputs. Train the MLP neural network model using the training sample set to obtain the MLP proxy model. S4. With minimizing the highest temperature and maximum thermal stress of the compartmentalized heat dissipation structure as the optimization objective, the parameters are optimized using a trained MLP surrogate model to obtain the heat dissipation slot parameters that enable the compartmentalized heat dissipation structure to meet the heat dissipation requirements and structural performance requirements.

Images