Anti-Total Dose Radiation Hardening Optimization Calculation Method and System Applied to High-Earth Orbit Satellites

Abstract

The present invention provides a method and system for optimizing the calculation of total dose radiation hardening for geostationary satellites, which relates to the technical field of satellite radiation resistance design. Aiming at high cost-effectiveness, a cost-effectiveness optimization model for total dose radiation hardening of satellites is constructed. This model takes the radiation design margin (RDM) as the evaluation index, and takes the quality grades and total dose resistance capabilities of different types of space components as the core parameters to establish a parameter model of the total dose radiation hardening cost and component grades and shielding quality. Then, with the cost-effectiveness as the objective function, a gradient-based optimization method is used to optimize the total dose radiation hardening of the satellite, and the uncertainties in the optimization process are analyzed and discussed. The present invention has strong operability and realizability, can improve the on-orbit reliability of the satellite system and effectively reduce the development cost on the premise of meeting the satellite life and total dose radiation hardening requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite anti-radiation design, and specifically, to a method and system for optimizing the calculation of total dose hardening applied to geostationary satellites. Background Art

[0002] The new generation of scientific satellites, including Jupiter exploration satellites, faint target detection satellites, high-resolution optoelectronic detection satellites, etc., are all moving towards high resolution, high sensitivity, hyperspectral, all-weather, and all-time directions, and will surely venture into unknown space regions in the future. However, there are a large number of high-energy protons, electrons, cosmic rays, aurora radiation, etc. in outer space, which can easily cause radiation damage to high-precision, high-resolution, and high-sensitivity detection payloads and components, affecting the satellite's detection mission.

[0003] The design of satellite total dose hardening is one of the key directions of space protection design. Previous design work relied too much on human experience and on-orbit flight test data. Most research focused on the layout hardening of a certain component or new shielding materials, and there has been a long-term lack of systematic and holistic design. Especially for geostationary satellites that will conduct space science exploration in the future, they will pass through extremely harsh space regions such as the inner and outer radiation belt centers and the SAA anomaly area multiple times, and there are no relevant radiation measurement data for these orbits. The components on the satellite are extremely vulnerable to radiation damage.

[0004] Currently, there is very little research on the design of satellite total dose hardening. Most of them are about the layout hardening design of a certain component, or the anti-radiation performance simulation and test of some new materials. After literature retrieval, Zhang Xuhui, Zhao Xuemin, and Li Xingji gave a total dose effect protection method and design for a typical spaceborne remote sensor optical system in the paper "Total Dose Effect Protection Method and Design for a Typical Spaceborne Remote Sensor Optical System" (see "Spacecraft Environment Engineering", 2018, Vol. 35, No. 4). They added a protective cover at the light entrance hood of the spaceborne optical remote sensor and conducted simulation and analysis, but it did not involve the satellite platform.

[0005] The invention patent with the publication number CN103832599A discloses a composite shielding method for anti-total dose effect on satellites. The method is as follows: double-layer materials are used for shielding, with a metal of low atomic number on the outer layer and a metal of high atomic number on the inner layer. The metal of low atomic number is aluminum, and the metal of high atomic number is tantalum. This invention uses double-layer materials for shielding, with a metal of low atomic number on the outer layer and a metal of high atomic number on the inner layer, but this invention only focuses on the material aspect and does not involve other aspects of the satellite, such as layout, components, etc.

[0006] The utility model patent with the publication number CN202337364U discloses a total ionizing dose protection device for communication satellites, including tantalum foil, thermal control multi-layers, and steel screws. The tantalum foil is installed on the structural board of the communication satellite through steel screws at the large-size openings of the communication satellite, and the thermal control multi-layers are fixed on the steel screws through press plates. However, this invention only targets the large-size openings of the satellite structural board and is only one aspect of the satellite radiation resistance design.

[0007] The invention patent with the publication number CN102490913A discloses a total dose shielding device, including a first low-Z layer for moderating and shielding primary electrons, a high-Z layer for scattering electrons and absorbing secondary bremsstrahlung photons, and a second low-Z layer for absorbing photoelectrons and backscattered electrons generated in the high-Z material and suppressing secondary photoelectron emission and electron backscattering generated by the interaction of X-rays with the material. However, this invention only relates to materials and does not cover other aspects of the satellite, such as layout, components, etc. Summary of the Invention

[0008] In view of the deficiencies in the prior art, the present invention provides a total dose hardening optimization calculation method and system for geostationary satellites.

[0009] According to the total dose hardening optimization calculation method and system for geostationary satellites provided by the present invention, the solutions are as follows:

[0010] In a first aspect, a total dose hardening optimization calculation method for geostationary satellites is provided. The method includes:

[0011] Step S1: Sort out the optimization design process of satellite total dose hardening, and construct a cost-effectiveness model for satellite system total dose hardening, that is, ROI = B / (B0 · C), where ROI is the cost-effectiveness ratio; B is the total dose resistance ability of components; B0 is the total dose resistance index of components; C is the total dose hardening cost;

[0012] Step S2: Simulate the space radiation environment during the satellite's lifespan based on relevant factors including the satellite launch window, operating orbit, lifespan requirements, solar activity, and the geomagnetic field, to obtain the dose-depth curve of the satellite's target orbit;

[0013] Step S3: Simplify the satellite's 3D model. When calculating, the smallest unit is considered as a single instrument box. Calculate the equivalent shielding thickness of the materials on the satellite, and conduct a 3D total dose refinement simulation on the satellite structure to obtain the total in-orbit radiation dose level B0;

[0014] Step S4: Determine the optimization object. To ensure that the components it contains do not fail in the radiation environment of the expected mission, allocate a reasonable design margin RDM to it;

[0015] Step S5: Calculate the total dose resistance index requirement B' of the optimization object according to B' = B0·RDM, select components, and preferentially select components with radiation resistance meeting the index requirement B', and determine its quality level M r and the total dose resistance B;

[0016] Step S6: Calculate the total dose hardening cost C of the optimization object;

[0017] Step S7: Take the return on investment ROI of the optimization object as the objective function, and use a gradient-based optimization algorithm to find the direction and iteration step size that make the objective function decrease the fastest within the variable range; continuously optimize and iterate the total dose hardening design scheme of the optimization object until the anti-addition design scheme with the optimal return on investment is obtained;

[0018] Step S8: For high-orbit satellites operating in a harsh radiation environment, after the above-mentioned optimization design is completed, continue to select other single machines or subsystems with a relatively high total dose radiation level as the target, and perform optimization design, repeating Step S4 to Step S7;

[0019] Step S9: Analyze the uncertainties in the optimization process, including the uncertainty of the radiation resistance B of the components, the uncertainty of the total dose resistance index B0, and the uncertainty of the total dose hardening cost C.

[0020] Preferably, the total dose hardening cost C in Step S6 is mainly related to the total dose hardening mass m of the satellite tid and the quality level M of the components used r , that is, C = C(m tid , M r ); the total dose hardening mass m tid includes the mass of the whole satellite structure, the single machine housing, shielding, circuit boards, and other related parts.

[0021] Preferably, the total dose hardening cost C = C(m tid , M r ), where M r is defined as the quality level of the components used in the satellite. The component quality level M r is divided into five levels from low to high radiation resistance: other, protocol level, industrial level, military level, and aerospace level.

[0022] Preferably, the total dose hardening cost C = C(m tid , M r ), where m tid is defined as the satellite's anti-addition mass, and the composition includes:

[0023]

[0024] In the formula, mcon Denote the satellite structure mass as \(m\). pi Denote the satellite skin mass as \(m\). ke Denote the mass of the single - machine housing as \(m\). tie Denote the mass of the local shielding of the single - machine as \(m\). sol Denote the mass of the solar wing that acts as a shield as \(m\). ele Denote the mass of the electronic devices as \(m\). other Denote the mass other than the aforementioned expressions as \(m\); \(f1\) is the mass calculation function.

[0025] Preferably, when establishing the component parameter cost model, all types of components used on the satellite are covered. When calculating a certain type of component, all kinds of components of the same type need to be included.

[0026] Preferably, to determine whether the single - machine housing plays a certain shielding role against high - energy particles, it is necessary to comprehensively optimize the three boundary conditions, namely the dose - depth curve constraint, the target single - machine mass constraint, and the total - dose resistance index requirement constraint during the satellite's lifetime, to obtain a more accurate result.

[0027] Preferably, when optimizing the layout position, assume that the variable interval where the single - machine coordinates are located is \(X = [p1\ p2\ \cdots\ p n T ; \(p i =(x i ,y i ,z i ), \(i\in[1,n]\). The basic iteration formula for optimization is shown as follows:

[0028]

[0029] In the formula, \(X\) is the \(n\) - dimensional design variable; \(X (k) is the initial point of the \(k\) - th iteration; \(\alpha k is the iteration step size; is the search direction; \(x i represents the \(x\) - coordinate of the \(i\) - th point \(x\), \(y i represents the \(y\) - coordinate of the \(i\) - th point \(y\), \(z i represents the \(z\) - coordinate of the \(i\) - th point \(z\); \(k\) represents the \(k\) - th optimization iteration.

[0030] Preferably, the search direction is calculated using the difference method shown in the following formula:

[0031]

[0032] Among them, represents the gradient, that is, the direction of the maximum change of the total - dose function; \(\Delta X\) represents the coordinate change difference.

[0033] Preferably, the main steps of the optimization algorithm in step S7 include:​

[0034] Step S7.1: Given an initial point X (0) and convergence accuracy ε, set counter k to 0;

[0035] Step S7.2: Calculate X (k) Gradient of a point And normalize the gradient;

[0036] Step S7.3: Determination If it satisfies, then X (k) The iteration stops and the optimal solution f(X (k) ), otherwise proceed to the next step of calculation;

[0037] Step S7.4: X (k) As a starting point, along Perform a one-dimensional search and calculate the optimal step size α k ;

[0038] Step S7.5: Set k is incremented by 1, and the process goes to step S7.2.

[0039] In a second aspect, a total dose reinforcement optimization calculation system for high-orbit satellites is provided, the system comprising:

[0040] Module M1: Sort out the optimization design process of satellite total dose reinforcement, and build a cost-effectiveness model for satellite system total dose reinforcement, that is, ROI = B / (B0·C), where ROI is cost-effectiveness; B is the total dose resistance capability of components; B0 is the total dose resistance index of components; C is the total dose reinforcement cost;

[0041] Module M2: Based on the satellite launch window, orbit, life requirements, solar activity, and geomagnetic field, the space radiation environment during the satellite life cycle is simulated to obtain the dose depth curve of the satellite target orbit;

[0042] Module M3: Simplify the satellite three-dimensional model, consider the smallest unit as a single instrument box, calculate the equivalent shielding thickness of the on-board materials, carry out a three-dimensional total dose refinement simulation of the satellite structure, and obtain the total radiation dose level B0 on ​​the satellite;

[0043] Module M4: Determine the optimization object and allocate a reasonable design margin RDM to it to ensure that the components it contains do not fail in the radiation environment of the expected task;

[0044] Module M5: Calculate the total dose resistance index requirement B' of the optimization object according to B'=B0·RDM, select components, give priority to components whose radiation resistance meets the index requirement B', and determine their quality level M r and total dose resistance B;

[0045] Module M6: Calculate the total ionizing dose hardening cost C of the optimization object;

[0046] Module M7: Take the return on investment (ROI) of the optimization object as the objective function, and use a gradient-based optimization algorithm to find the direction and iteration step size that make the objective function decrease the fastest within the variable range; continuously optimize and iterate the total ionizing dose hardening design scheme of the optimization object until the anti-addition design scheme with the optimal ROI is obtained;

[0047] Module M8: For high-orbit satellites operating in a harsh radiation environment, after the optimization design of the above objectives is completed, continue to select other single machines or subsystems with relatively high total ionizing dose radiation levels as the targets for optimization design, and repeat Modules M4 to M7;

[0048] Module M9: Analyze the uncertainties in the optimization process, including the uncertainty of the radiation resistance B of components, the uncertainty of the total ionizing dose index B0, and the uncertainty of the total ionizing dose hardening cost C.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. Starting from the engineering practice, the present invention realizes improving the total ionizing dose resistance ability of satellites from the system level, and solves the defect that the previous total ionizing dose hardening design work of satellites overly relies on human experience;

[0051] 2. The present invention is oriented to high cost-effectiveness. The optimized objectives can not only meet the requirements of satellite life and radiation hardening, but also effectively reduce the development cost, and can provide reference for subsequent satellite anti-addition design and cost reduction, with significant practical significance and engineering value. Description of the Drawings

[0052] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects, and advantages of the present invention will become more apparent:

[0053] Figure 1 It is the total ionizing dose hardening optimization calculation process for the satellite;

[0054] Figure 2 It is the curve of the total ionizing dose varying with the shielding thickness during the on-orbit life of the high-orbit satellite;

[0055] Figure 3 It is to search for the optimal position of the target single machine layout;

[0056] Figure 4 It is the curve of the total ionizing dose index change before and after optimization. Detailed Embodiments

[0057] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all fall within the protection scope of the present invention.

[0058] The embodiment of the present invention provides an anti-total-dose hardening optimization calculation method applied to high-earth orbit (HEO) satellites. The method includes: satellite total-dose refined simulation, component parameter cost modeling, and satellite anti-total-dose hardening optimization calculation. The present invention solves the problems of insufficient anti-total-dose design margin and too high component selection cost of HEO satellites in the harsh radiation environment at the present stage, and can provide a new idea for the anti-radiation protection design of HEO satellites, the selection of space components, and the reduction of model costs.

[0059] The object of this embodiment is a high-earth orbit (HEO) satellite with a designed life of 8 years, a perigee of 1200 km, an apogee of 36000 km, and an inclination angle of 63.4°. It crosses the centers of the inner and outer radiation belts multiple times a day. Compared with low-orbit or low-inclination satellites, due to the lack of geomagnetic field protection in this orbit, high-energy particles in space are more likely to affect the on-orbit safety of the satellite.

[0060] (1) On the premise that the satellite meets the functional and performance requirements proposed by users, it can adapt to the radiation environment in the orbital space to ensure that the satellite completes its on-orbit mission, which means benefit; the project cost from satellite development to on-orbit maintenance paid to achieve this goal is its main cost. For high cost-effectiveness, under the constraints of comprehensive performance, function, reliability, life, cost, etc., anti-total-dose hardening optimization calculation is carried out, as Figure 1 shown.

[0061] Define the cost-effectiveness ratio model of the anti-total-dose hardening of the satellite system:

[0062]

[0063] In the formula, ROI is the cost-effectiveness ratio; C is the cost of the satellite's anti-total-dose hardening; B is the anti-radiation ability of the component; B0 is the anti-radiation index of the component; RDM = B / B0 is the radiation design margin.

[0064] The larger the ROI value, the better the satellite anti-radiation hardening design scheme. The ROI analysis is for the design scheme that does not meet the requirements and needs to be redesigned until it meets the requirements.

[0065] (2) According to the six orbital elements, 8-year life, etc. of the HEO satellite, using space radiation environment prediction software, select radiation environment models such as AP-9 / AE-9, JPL, ESP, etc., and obtain the dose-depth curve during the life period of the HEO satellite, asFigure 2 As shown in the figure. Without considering the overall satellite structure and the shielding of individual components, the total ionizing dose suffered by a general single component (with a structural wall thickness of 2.5 mm) is approximately 260 krad(Si).

[0066] (3) Using the overall satellite three-dimensional structure model, reasonably simplify it. When calculating, the smallest unit is considered as the single-component instrument box. Calculate the equivalent shielding thickness of the materials on the satellite, and conduct a three-dimensional total dose refined simulation on the satellite structure. The results show that the equivalent aluminum shielding thickness range of the radiation-sensitive single components inside the satellite platform is 5.2 - 6.79 mm. After interpolating through the dose-depth curve, the total dose index of the corresponding single components is 17.9 - 47.8 krad(Si).

[0067] (4) The single component with the highest total dose level is the south cabin service unit, which is located on the upper side plate of the satellite in the +Y direction. Determine the south cabin service unit as the optimization object. To ensure that it does not fail in the radiation environment of the expected mission, the design margin is taken as 1.5 RMD (ESA recommends 1.2 for the GEO orbit, and greater than 2 for other orbits).

[0068] (5) Calculate the total dose resistance index requirement B' of the components according to B' = B0·RDM. The radiation resistance of the components inside this single component must be greater than 71.7 krad(Si). Conduct component selection. Taking the MOS transistor as an example, to meet the requirement of being greater than 71.7 krad(Si), the device level must be selected as the space grade (radiation resistance of 100 krad(Si)).

[0069] (6) Calculate the cost C of the satellite's total dose hardening, which is mainly related to the total dose hardening mass m of the satellite tid and the quality grade M of the components used r , that is, C = C(m tid , M r ). The analytical formula is as follows:

[0070]

[0071] In the formula, a1, b1, c1, a2, b2, c2 are constants; m, M r define the satellite mass and component grade. For the convenience of quantification, here the component quality grade is divided into five grades from low to high radiation resistance: other, protocol grade, industrial grade, military grade, and space grade, corresponding to M r from 1 to 5 in sequence; f1, f2 are weight coefficients.

[0072] The total dose hardening mass m tid , mainly includes:

[0073]

[0074] Wherein, m con represents the satellite structure mass, m pi represents the satellite skin mass, m ke represents the chassis mass of a single unit, m tie represents the local shielding mass of a single unit, m sol represents the mass of the solar panel that acts as a shield, m ele represents the mass of electronic devices, m other represents other masses, and f is a mass calculation function.

[0075] The changed mass △m of the south cabin service unit before and after optimization tid , where the satellite structure m con , the skin m pi , the mass m of the shielded part of the solar panel sol , the mass m of electronic devices ele , and other masses m other have not changed. Only the chassis m ke of the service unit and the component patches m tie inside have minor changes, that is, △m tid = m ke + m tie .

[0076] Perform cost modeling on components, adopt the PLS algorithm ((Partial Least Squares method), and construct the functional relationship between the cost C and the component grade M r . The cost model basically covers the cost models of various types of components used on the satellite. For example, for memories, including SRAM / EEPROM / PROM / SDRAM / MRAM, etc., the relationship between the cost of commonly used components on the satellite and the quality grade is shown in Table 1 below:

[0077] Table 1 Relationship between the cost of commonly used components on the satellite and the quality grade

[0078]

[0079]

[0080] Estimated according to the above, the component selection cost of the south cabin service unit is about 1.22 million yuan.

[0081] (7) Optimize the design of the south cabin service unit.

[0082] Calculate the cost-effectiveness ratio ROI of the total dose hardening of the south cabin service unit, that is, ROI = RDM / C = B / (B0·C) = (100 / 47.8) / 122 ≈ 0.017 (1 / 10,000 yuan).

[0083] Taking the target cost-effectiveness ratio ROI as the optimization goal, sort out many constraint conditions such as satellite weight, layout position, and single unit size:

[0084]

[0085] In the formula, RDM th is the minimum radiation design margin, which should generally be greater than 2, depending on factors such as satellite orbit, predicted radiation environment level, and device irradiation test level; (x th , y th , z th ) is the three-dimensional coordinate threshold of the single-unit layout, which is generally limited by the size of the installation position and the satellite's center-of-mass requirements; d L , d U are the lower and upper limits of the single-unit wall thickness, which are generally limited by the structural strength and weight requirements of the single unit; m th is the satellite mass threshold.

[0086] Considering that there are many design variables in the objective function and the variable range is relatively large, a gradient-based optimization algorithm is adopted to find the direction and iteration step size that make the objective function decrease fastest within the variable range.

[0087] Optimize by adopting total-dose hardening design for single units (for example: pasting lead sheets on the surface of components, adjusting the single-unit wall thickness or housing material, etc.) and total-dose hardening design for the entire satellite (for example: adjusting the single-unit layout, changing the installation orientation of single units, etc.) until an optimal design plan with the best cost-effectiveness is obtained.

[0088] Taking the optimization of the single-unit layout position as an example, assume that the variable range where the single-unit coordinates are located is X = [p1 p2…p n T ; p i = (x i , y i , z i ), i ∈ [1, n]. The basic iteration formula for optimization is shown as follows:

[0089]

[0090] In the formula, X is the n-dimensional design variable; X (k) is the initial point of the k-th iteration; α k is the iteration step size; is the search direction; x i represents the x-direction coordinate of the i-th point x, y i represents the y-direction coordinate of the i-th point y, z i represents the z-direction coordinate of the i-th point z; k represents the k-th optimization iteration.

[0091] The search direction is calculated using the difference method shown in the following formula:

[0092] ​

[0093] The main steps of the optimization algorithm are:

[0094] a. Given an initial point X (0) and convergence accuracy ε, set counter k to 0;

[0095] b. Calculate X (k) Gradient of a point And normalize the gradient;

[0096] c. Judgment If it satisfies, then X (k) The iteration stops and the optimal solution f(X (k) ), otherwise proceed to the next step of calculation;

[0097] d. X (k) As a starting point, along Perform a one-dimensional search and calculate the optimal step size α k ;

[0098] e. Order k increases by 1 and goes to b.

[0099] In the above optimization process, the one-dimensional search process requires multiple three-dimensional shielding simulations. In order to improve the optimization speed, an initial step size can be set artificially, and α can be adjusted according to the convergence situation. k Make appropriate adjustments.

[0100] Taking the cost-effectiveness ratio of the radiation reinforcement of the south cabin service unit as the optimization goal and RDM>1.5 as the constraint condition, optimization is carried out from three aspects: single-machine layout, structural design, and component selection: ① According to the overall design of the satellite, in the layout space allowed by the single machine, find the moving direction that can increase the equivalent shielding thickness of the single machine the fastest, such as Figure 3 After the optimization direction is determined, in order to improve the calculation efficiency, the search step length is manually specified, and a three-dimensional shielding analysis is performed on the six coordinate positions in the moving direction. The results show that when the single machine moves to position 4, its total dose index decreases the most; ② When the weight of the single machine allows, the wall thickness of the single machine is increased from 2.5mm in the original plan to 3mm, and △m is calculated. tidLess than 0.01 kg; ③ After the first two steps of optimization, the radiation resistance index B0 of the components is reduced from the original 47.8 krad(Si) to 28.7 krad(Si). Considering the constraint of RDM>1.5, the radiation resistance requirement of the components is 43.1 krad(Si). Compared with the original plan, the selectable range of the components is greatly improved. Accordingly, the components with a large quantity and high price in a single machine are optimized, including reducing the quality grade of the components and the packaging form of the devices. For example, the aerospace-grade MOS transistors such as IRHNJ67230SCS and JANSR2N7334 are respectively reduced to the industrial-grade IRF5NJ3315 and IRFG110, and the anti-fuse FPGA A54SX72A-CQ208B and the PROM of the UT28F256QLET-45UCC type are changed from ceramic packaging to plastic packaging such as A54SX72A-PQ208B and AT28HC256-90DM / 883. The radiation resistance B of the downgraded devices is 60 krad(Si).

[0101] (8) After comparison, the RDM after design optimization is 60 / 28.7 = 2.1, which is equivalent to the RDM before optimization and both meet the requirements of the radiation resistance design margin. However, the quality grade of the components can be reduced from aerospace-grade to industrial-grade. It is estimated that this improvement can save about 300,000 yuan in cost for the single-machine design (the cost reduction exceeds 20%), and the corresponding cost-effectiveness ratio is also significantly improved.

[0102] For high-orbit satellites with a harsh radiation environment, after the above-mentioned target optimization design is completed, other single machines or subsystems with a relatively high total dose radiation level are continued to be selected as the optimization targets for optimization design, repeating (4) to (7), and the whole process always requires meeting the satellite life and radiation resistance requirements.

[0103] (9) Analyze the uncertainties in the optimization process. Considering the uncertainties of B, B0, and C, the overall optimization model is as follows:

[0104]

[0105] In the formula, P L is the lower limit of the cost-effectiveness ratio under a given confidence level 1-α. The radiation resistance B of the components follows a distribution with a probability density function of Pdf B , and Pdf B reflects the uncertainty of the radiation resistance of the components, that is, the difference in the radiation resistance of different individuals of the same batch of components, which is mainly affected by the discreteness of factors such as the materials and processes of the components. The satellite radiation index B0 follows a distribution with a probability density function of Pdf B0 , and Pdf B0It reflects the uncertainty of satellite radiation indicators, i.e., the deviation of satellite radiation indicators, which is mainly affected by the randomness of the radiation environment and the accuracy of radiation models, such as the influence of geomagnetic activity, solar activity, etc. on the radiation environment. The cost C of satellite radiation hardening follows a distribution with a probability density function of Pdf C and Pdf C reflects the uncertainty of the cost of satellite radiation hardening, i.e., the deviation of the estimated result of the cost of satellite radiation hardening, which is mainly affected by the accuracy of the radiation hardening cost model.

[0106] An optimization calculation method for total dose radiation hardening of geostationary satellites provided by an embodiment of the present invention starts from the actual engineering situation, realizes improving the total dose radiation resistance ability of satellites from the system level in a harsh radiation environment, and solves the defect that the previous total dose radiation hardening design work of satellites relied too much on human experience; aiming at high cost-effectiveness, the optimized goal can not only meet the requirements of satellite life and radiation hardening, but also effectively reduce the development cost, and can provide reference for subsequent satellite radiation hardening design and cost reduction, having significant practical significance and engineering value.

[0107] Those skilled in the art know that in addition to implementing the system and its various devices, modules, and units provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system and its various devices, modules, and units provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers to achieve the same functions. Therefore, the system and its various devices, modules, and units provided by the present invention can be regarded as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be regarded as the structure within the hardware component; the devices, modules, and units for implementing various functions can also be regarded as both software modules for implementing the method and the structure within the hardware component.

[0108] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined arbitrarily with each other.

Claims

1. An optimization calculation method for total dose radiation hardening applied to geostationary satellites, characterized in that, Including: Step S1: Sort out the optimization design process of satellite total dose radiation hardening, and construct the cost-effectiveness model of satellite system total dose radiation hardening, that is, ROI = B / (B0·C), where ROI is the cost-effectiveness ratio; B is the total dose resistance ability of components; B0 is the total dose resistance index of components; C is the cost of total dose radiation hardening; Step S2: According to relevant factors including satellite launch window, operating orbit, lifespan requirements, solar activity, and geomagnetic field, simulate the space radiation environment during the satellite lifespan to obtain the dose-depth curve of the satellite target orbit; Step S3: Simplify the satellite 3D model. When calculating, the minimum unit is considered as a single instrument box. Calculate the equivalent shielding thickness of the materials on the satellite, and conduct 3D total dose refinement simulation on the satellite structure to obtain the total radiation dose level B0 inside the satellite; Step S4: Determine the optimization object, and allocate a reasonable design margin RDM to it to ensure that the components it contains do not fail in the radiation environment of the expected mission; Step S5: Calculate the total dose radiation tolerance index requirement B' of the optimization object according to B' = B0·RDM, select components, choose components whose radiation tolerance meets the index requirement B', and determine their quality level M r and the total dose radiation tolerance B; Step S6: Calculate the cost C of total dose radiation hardening of the optimization object; Step S7: Take the cost-effectiveness ratio ROI of the optimization object as the objective function, and find the direction and iteration step size that make the objective function decline the fastest within the variable interval; continuously optimize and iterate the total dose radiation hardening design scheme of the optimization object until the anti-addition design scheme with the optimal cost-effectiveness ratio is obtained; Step S8: For high-orbit satellites operating in a harsh radiation environment, after the above-mentioned optimization design of the target is completed, continue to select other single machines or subsystems with relatively high total dose radiation levels as the target for optimization design, and repeat Step S4 to Step S7; Step S9: Analyze the uncertainties in the optimization process, including the uncertainty of the radiation resistance ability B of components, the uncertainty of the total dose resistance index B0, and the uncertainty of the total dose radiation hardening cost C.

2. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 1, wherein The total dose radiation hardening cost C in step S6 is mainly related to the total dose radiation hardening mass m of the satellite tid , the quality grade M of the components used r , that is, C = C(m tid , M r ); the total dose radiation hardening mass m tid includes the mass of the entire satellite structure, the chassis of the single machine, shielding, circuit boards, and other relevant parts of the satellite.

3. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 2, wherein, The total dose hardening cost C = C(m tid , M r ), where M r is defined as the quality grade of the components used in the satellite. The component quality grade M r is divided into five grades: other, protocol level, industrial level, military level, and aerospace level in ascending order of radiation resistance.

4. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 2, characterized in that The anti-total-dose hardening cost C = C(m tid , M r ), where m tid is defined as the anti-hardening added mass of the satellite, and the composition includes: where m con represents the mass of the satellite structure; m pi represents the mass of the satellite skin; m ke represents the mass of the single-machine housing; m tie represents the mass of the single-machine local shielding; m sol represents the mass of the solar wing that acts as a shield; m ele represents the mass of the electronic device; m other represents the mass other than the foregoing expressions; f1 is the mass calculation function.

5. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 2, wherein When establishing the component parameter cost model, cover all types of components used on the satellite. When calculating a certain type of component, all types of components of the same type need to be included.

6. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 2, wherein To judge whether the single machine case plays a shielding role for high-energy particles, it is necessary to comprehensively optimize the three boundary conditions of the dose-depth curve constraint, the target single machine mass constraint, and the total dose resistance index requirement constraint during the satellite lifespan to obtain more accurate results.

7. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 1, characterized in that When optimizing the layout position, assume that the variable range where the single-machine coordinates are located is X = [p1 p2…p n T ;​ p i = (x i , y i , z i ), i ∈ [1, n], and the basic iterative formula adopted for optimization is shown as follows: where X is an n-dimensional design variable; X (k) is the initial point of the k-th iteration; αk is the iteration step size; is the search direction; x i represents the x-direction coordinate of the i-th point x, y i represents the y-direction coordinate of the i-th point y, z i represents the z-direction coordinate of the i-th point z; k represents the k-th optimization iteration.

8. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 7, wherein The search direction is calculated by the difference method shown in the following formula: Among them, represents the gradient, that is, the direction of the maximum change of the total dose function; ΔX represents the coordinate change difference.

9. The anti-total-dose hardening optimization calculation method applied to high-orbit satellites according to claim 8, characterized in that, The main steps of the optimization algorithm in Step S7 include: Step S7.1: Given the initial point X (0) and the convergence accuracy ε, set the counter k to 0; Step S7.2: Calculate X (k) Gradient of the point And normalize the gradient; Step S7.3: Determine If satisfied, then X (k) is the optimal point, iteration stops, and the optimal solution f(X (k) ) is output; otherwise, proceed to the next calculation; Step S7.4: Starting from X (k) , perform a one-dimensional search along to calculate the optimal step size αk; Step S7.5: Let k increment by 1 and go to Step S7.

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10. An anti-total-dose radiation hardened optimization calculation system applied to high-orbit satellites, characterized in that, Including: Module M1: Sort out the optimization design process of satellite total dose radiation hardening, and construct the cost-effectiveness model of satellite system total dose radiation hardening, that is, ROI = B / (B0·C), where ROI is the cost-effectiveness ratio; B is the total dose resistance ability of components; B0 is the total dose resistance index of components; C is the cost of total dose radiation hardening; Module M2: According to relevant factors including satellite launch window, operating orbit, lifespan requirements, solar activity, and geomagnetic field, simulate the space radiation environment during the satellite lifespan to obtain the dose-depth curve of the satellite target orbit; Module M3: Simplify the 3D satellite model. When calculating, the minimum unit is considered as a single instrument box. Calculate the equivalent shielding thickness of the materials on the satellite, and conduct a refined 3D simulation of the total dose for the satellite structure to obtain the total radiation dose level B0 inside the satellite; Module M4: Determine the optimization object. To ensure that the components it contains do not fail in the radiation environment of the expected mission, allocate a reasonable design margin RDM to it; Module M5: Calculate the total ionizing dose (TID) tolerance requirement B' of the optimization object according to B' = B0·RDM, select components, choose components with radiation resistance meeting the index requirement B', and determine their quality level M r and the total ionizing dose (TID) tolerance B; Module M6: Calculate the cost C of the total dose hardening of the optimization object; Module M7: Take the return on investment ROI of the optimization object as the objective function, and find the direction and iteration step size that make the objective function decrease the fastest within the variable range; continuously optimize and iterate the total dose hardening design scheme of the optimization object until the anti-addition design scheme with the optimal return on investment is obtained; Module M8: For high-orbit satellites operating in a harsh radiation environment, after the above-mentioned optimal design is completed, continue to select other single machines or subsystems with relatively high total dose radiation levels as the targets for optimal design, and repeat Module M4 to Module M7; Module M9: Analyze the uncertainties in the optimization process, including the uncertainty of the radiation resistance B of the components, the uncertainty of the total dose resistance index B0, and the uncertainty of the total dose hardening cost C.

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