Multi-aircraft combined spacecraft reliability index system construction method

Abstract

The invention discloses a method for constructing a reliability index system of a multi-aircraft combined spacecraft. The method comprises the following steps: analyzing a multi-aircraft combined spacecraft construction process and task functions, and decomposing total task requirements to a key flight event, a single aircraft and a specific function system from top to bottom for the combined spacecraft; distributing the whole life cycle task reliability index to each aircraft and each single-machine device in each task stage; a cross-aircraft reliability modeling and predicting method is adopted, task reliability indexes of a launching and autonomous flight task, an assembling and building task and a propellant supplementing and cabin-out activity task are predicted, the coordination of the task reliability indexes distributed by a function system and a single machine is checked, and it is guaranteed that the task time dimension and the function logic dimension both meet the requirements; and adjusting functions and a hardware configuration scheme according to a test result in combination with an aircraft system optimization design method, and finally forming a task reliability index system of the multi-aircraft combined spacecraft. Therefore, a good foundation is laid for reliability quantification work.

Description

Technical Field

[0001] The present invention relates to the technical field of spacecraft overall design, and in particular to a method for constructing a reliability index system of a multi-spacecraft combined spacecraft. Background Art

[0002] Usually, the engineering department only proposes the mission reliability index of the spacecraft as a whole. This index needs to be gradually decomposed into single-machine products to be verifiable and guide reliability design work. For a single-flight spacecraft with a single mission, the mission reliability index has a clear connotation and a relatively fixed functional composition. Traditional allocation methods such as the equal distribution method and the scoring method can be used to complete the step-by-step allocation of the index.

[0003] However, a multi-vessel combination spacecraft, with the space station as a typical example, is usually assembled and built by a single vehicle after launch and autonomous flight in orbit through rendezvous and docking and transfer technology. It will go through the independent flight in orbit and assembly and construction stages of a single vehicle. After the construction is completed, the combination will fly in orbit for a long time under the care and maintenance support of astronauts. The mission profile of the combined spacecraft is complex, and the configuration of the combined spacecraft changes dynamically. In addition to maintaining the long-term stable operation of the platform, it is also necessary to carry out short-term special tasks such as manned residence support, visiting spacecraft rendezvous and docking, extravehicular activities, and application mission support according to the mission plan. Long-term autonomous flight missions are the basis of special tasks; but at the same time, visiting flights provide manpower and material guarantees for the delivery of astronauts, various spare parts and materials to the spacecraft, and for the on-orbit maintenance and repair. Through extravehicular activities, the replacement and disposal of key extravehicular equipment such as solar panels can restore the spacecraft to normal from abnormal failures, providing strong support for the reliable and safe operation of the spacecraft. Therefore, special tasks also serve long-term autonomous flight missions.

[0004] The dynamic changes in the composition and configuration of the aircraft, the mutual support and restraint between long-term autonomous flight missions and short-term special missions, and the irregular timing of the implementation of short-term missions have led to difficulties in defining the connotation of mission reliability indicators, defining the scope of implementation mission products, and clarifying mission time, which directly affects the effectiveness of reliability indicator prediction and evaluation. Summary of the invention

[0005] The present invention provides a method for constructing a reliability index system for a multi-vehicle combined spacecraft, which solves the problems of fuzzy connotations of multi-level task reliability indicators under dynamic changes in the functional composition of the multi-vehicle combined spacecraft and mutual coupling of tasks, and difficulty and incoordination in allocating indicators to functions and equipment, and can lay a good foundation for reliability quantification work.

[0006] In the first aspect, a method for constructing a reliability index system of a multi-vehicle combined spacecraft is provided, including:

[0007] Analysis of the construction process and mission functions of multi-vehicle combined spacecraft, breaking down the total mission requirements into key flight events, single vehicles and specific functional systems from top to bottom for the combined spacecraft;

[0008] Allocate the mission reliability index of the entire life cycle to each aircraft and each single equipment in each mission phase;

[0009] Adopt cross-vehicle reliability modeling and prediction methods to predict the mission reliability indicators of launch and autonomous flight missions, assembly and construction missions, propellant replenishment and extravehicular activity missions, and verify the coordination of mission reliability indicators of functional systems and single-vehicle allocations to ensure that requirements are met in both mission time and functional logic dimensions;

[0010] According to the test results and combined with the aircraft system optimization design method, adjust the function and hardware configuration plan, and adjust and optimize the function and hardware mission reliability indicators.

[0011] In conjunction with the first aspect, in certain implementations of the first aspect, decomposing the overall mission requirements into key flight events, a single aircraft, and specific functional systems includes:

[0012] The flight event assurance chain analysis combined with the probabilistic risk analysis (PRA) method is used to identify the initial events that lead to the failure of the top-level mission, conduct an independence analysis of the initial events, and determine the spacecraft's autonomous flight mission and the short-term special missions implemented on this basis, including rendezvous and docking missions, transfer missions, propellant replenishment missions, and extravehicular activity missions as the second-level missions;

[0013] Analyze and determine the functional systems corresponding to completing the mission. The functional systems that ensure the platform's autonomous flight mission include the platform's functional systems for structural bearing and sealing, power supply and distribution, information management, control and propulsion, thermal management, and manned environment control; the functional systems that ensure special missions include the mission functional systems for rendezvous and docking, transfer, propellant replenishment, extravehicular activities, and payload test support.

[0014] In conjunction with the first aspect, in certain implementations of the first aspect, allocating the life cycle mission reliability index to each aircraft and each stand-alone device in each mission phase includes:

[0015] For the top-level life and reliability indicators, indicators are allocated based on the multi-aircraft assembly as a whole; first, in comparison with the aforementioned mission function analysis, the system mission reliability indicators are allocated to the assembly's platform functions of structural bearing and sealing, power supply and distribution, information management, control and propulsion, thermal management, and manned environment control, as well as rendezvous and docking, transfer, propellant replenishment, extravehicular activities, and load test support; secondly, based on the configuration of the assembly's related functions in each compartment and in accordance with the redundancy relationship within the aircraft and between aircraft, the reliability indicators of each function of the assembly are allocated to the corresponding functions of the specific compartment; finally, they are allocated to the specific hardware products in the specific compartment.

[0016] In combination with the first aspect, in some implementations of the first aspect, a proportional combination allocation method is used to allocate the task reliability index to the new and old systems according to the proportion of the predicted failure probability; its mathematical expression is:

[0017]

[0018] Where: - Failure rate indicator of the new system (1 / h);

[0019] - the failure rate assigned to the i-th subsystem in the new system (1 / h);

[0020] λ s老 - Failure rate of the old system (1 / h);

[0021] λ i老 -Failure rate of the i-th subsystem in the old system (1 / h).

[0022] In conjunction with the first aspect, in certain implementations of the first aspect, the coordination of the reliability index of the task assigned to the inspection function system and the single machine is ensured to meet the requirements in both the task time dimension and the functional logic dimension, including:

[0023] Verify the feasibility of maintenance from two levels: single-machine mechanical, electrical, and fluid interface design, as well as system maintainability design. Single-machine-level maintenance analysis confirms whether the product is an on-orbit replaceable unit (ORU), and whether the mechanical fasteners and electrical connectors can be quickly and safely removed and plugged in. System-level maintainability analysis confirms whether ORU faults can be detected, located, and isolated, whether the overall layout supports visual accessibility, and whether the power supply and information system design supports fault isolation. On the basis of confirming that the maintenance is feasible, further analyze the support resource situation to confirm whether there are maintenance spare parts and maintenance operation tools on orbit. For regularly replaced products, confirm the matching of spare parts launch uplink planning and on-orbit life consumption. For extravehicular maintenance operation projects, confirm the extravehicular mission arrangements.

[0024] In combination with the first aspect, in certain implementations of the first aspect, through maintainability inspection, it is determined that on-orbit maintenance meets the requirements of repair as good as new, and the mission time during reliability prediction is determined according to the maintenance strategy; if spare parts are stored on-orbit and it is verified that the repair and replacement can be completed within the time allowed by the system, it is confirmed as an on-orbit cold backup, thereby correcting the series non-redundant functions and products in the original system to a cold reserve model or a voting model.

[0025] In conjunction with the first aspect, in certain implementations of the first aspect, adjusting the function and hardware configuration scheme according to the inspection result in combination with the aircraft system optimization design method, and adjusting and optimizing the function and hardware task reliability index include:

[0026] Based on the design of multi-vehicle combined spacecraft optimization system, reasonable and coordinated single-machine reliability indicators can be finally determined through reliability modeling and prediction iteration; the indicator optimization methods include:

[0027] Carry out on-orbit maintainability design of single-unit products and determine appropriate maintenance cycles;

[0028] Determine the established maintenance cycle as the product task time;

[0029] Determine whether to reserve spare parts on orbit or on the ground based on the product's redundancy, functional importance, and the urgency of the consequences of a failure;

[0030] The maintenance cycle and maintenance support measures of reserve spare parts are modeled, and the maintainable products with reserve spare parts are approximated as cold reserves or voting models for prediction. The mission reliability index of the final single-machine product is determined based on the prediction results.

[0031] In combination with the first aspect, in some implementations of the first aspect, the method further includes:

[0032] Form a mission reliability index system for multi-vehicle combined spacecraft.

[0033] In conjunction with the first aspect, in certain implementations of the first aspect, forming a mission reliability index system for a multi-vehicle combined spacecraft includes:

[0034] Complete the decomposition of the system's top-level mission-level reliability indicators into long-duration flight missions and short-duration special missions, and determine the mission reliability indicators of each mission phase, each aircraft, each aircraft subsystem, and a single aircraft;

[0035] A comprehensive analysis is conducted on the timing of generating data samples that can be used for quantitative prediction and evaluation during the ground-based development and on-orbit flight of various levels of spacecraft products. Combined with the on-orbit mission profile, the timing and requirements for quantitative prediction and evaluation of the second-tier mission reliability indicators are determined to form a mission reliability indicator system for multi-vehicle combination spacecraft.

[0036] In conjunction with the first aspect, in certain implementations of the first aspect, the mission reliability index system of the multi-vehicle combined spacecraft includes:

[0037] During the single-cabin flight phase, the system mission reliability indicators include the autonomous flight mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, and control and propulsion mission reliability of cabin A; the system mission reliability indicators also include the propellant replenishment support mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the propulsion replenishment functional mission reliability of cabin A; the system mission reliability indicators also include the astronaut and cargo transportation support mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the rendezvous and docking functional mission reliability of cabin A; the system mission reliability indicators also include the extravehicular activity support mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the reliability of the robotic arm and extravehicular support functional mission of cabin A;

[0038] During the assembly and construction stage, the system mission reliability indicators include the autonomous flight mission reliability of the B compartment, and the corresponding functional / subsystem reliability indicators include the structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, and control and propulsion mission reliability of the B compartment; the system mission reliability indicators also include the docking and transfer mission reliability of the B compartment, and the corresponding functional / subsystem reliability indicators include the rendezvous and docking functional mission reliability of the B compartment; the system mission reliability indicators also include the assembly and construction mission reliability of the A compartment + B compartment combination, and the corresponding functional / subsystem reliability indicators include the transfer functional mission reliability of the A and B compartments; the system mission reliability indicators also include the autonomous flight mission reliability of the A compartment + B compartment combination, and the corresponding functional / subsystem reliability indicators include the A compartment + B compartment combination Structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, control and propulsion mission reliability; system mission reliability indicators also include autonomous flight mission reliability of C compartment, and the corresponding functional / subsystem reliability indicators include structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, control and propulsion mission reliability of C compartment; system mission reliability indicators also include docking and transfer mission reliability of C compartment, and the corresponding functional / subsystem reliability indicators include rendezvous and docking functional mission reliability of C compartment; system mission reliability indicators also include assembly and construction mission reliability distribution of A compartment + B compartment + C compartment, and the corresponding functional / subsystem reliability indicators include A+B compartment and C compartment transfer functional mission reliability;

[0039] During the assembly and construction phase and the operation phase, the system mission reliability indicators include the reliability of the autonomous flight mission of the three-cabin combination, and the corresponding functional / subsystem reliability indicators include the structural mission reliability of the A-cabin + B-cabin + C-cabin combination, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, and control and propulsion mission reliability;

[0040] During the operation phase, for the completed combination, the system mission reliability indicators include the propellant replenishment support mission reliability, and the corresponding function / subsystem reliability indicators include the propulsion replenishment function mission reliability of the A cabin + B cabin + C cabin combination; the system mission reliability indicators also include the astronaut and cargo transportation support mission reliability, and the corresponding function / subsystem reliability indicators include the propulsion replenishment function mission reliability of the A cabin + B cabin + C cabin combination; the system mission reliability indicators also include the extravehicular activity support mission reliability, and the corresponding function / subsystem reliability indicators include the rendezvous and docking function mission reliability of the A cabin + B cabin + C cabin combination.

[0041] Compared with the prior art, the solution provided by the present invention includes at least the following beneficial technical effects:

[0042] 1) The indicator allocation process with the assembly as an organic whole is closely centered around the reliability relationship between mission-related functions, breaking through the limitation of simple serial connection based on subsystems in the past. It fully considers the configuration relationship between functions in subsystems and between cabins, and improves the accuracy of indicator allocation.

[0043] 2) A reliability index system applicable to multi-aircraft combined spacecraft systems was established to solve the problem of uncoordinated index allocation under the mutual coupling of tasks in the dynamically changing functional components of the combined spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention discloses a flow chart for quantitatively evaluating the reliability of a multi-vehicle combined spacecraft.

[0045] Figure 2 It is a schematic diagram of the combination task reliability index allocation process of the present invention. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] like Figure 1 As shown, the present invention provides a method for constructing a reliability index system of a multi-aircraft combined spacecraft. The specific steps are as follows.

[0048] Step 1: Analyze the construction process and mission functions of the multi-vehicle combination spacecraft. Take the combined spacecraft as an organic whole and decompose the total mission requirements from top to bottom into key flight events, single spacecraft and specific functional systems.

[0049] The flight event assurance chain analysis combined with the probabilistic risk analysis (PRA) method is used to identify the initial events that lead to the failure of the top-level mission, conduct an independence analysis of the initial events, and determine the spacecraft autonomous flight mission and the short-term special missions implemented on this basis, including rendezvous and docking missions, transfer missions, propellant replenishment missions, and extravehicular activity missions as the second-level missions. Further analysis is performed to determine the functional systems corresponding to the missions. The functional systems that ensure the platform's autonomous flight missions include platform functional systems such as structural bearing and sealing, power supply and distribution, information management, control and propulsion, thermal management, and manned environment control; the functional systems that ensure special missions include rendezvous and docking, transfer, propellant replenishment, extravehicular activities, and load test support functional systems.

[0050] Step 2: Allocate the mission reliability index of the entire life cycle to each aircraft and each single equipment in each mission phase.

[0051] In terms of top-level life and reliability indicators, indicators are allocated based on the multi-spacecraft assembly as a whole. First, in comparison with the aforementioned mission function analysis, the system mission reliability indicators are allocated to the assembly's platform functions such as structural bearing and sealing, power supply and distribution, information management, control and propulsion, thermal management, manned environment control, as well as rendezvous and docking, transfer, propellant replenishment, extravehicular activities, and load test support functions; secondly, based on the configuration of the assembly's related functions in each compartment, and in accordance with the redundancy relationship within the spacecraft and between spacecraft, the reliability indicators of each function of the assembly are allocated to the corresponding functions of the specific compartment; and finally allocated to the specific hardware products of the specific compartment. The entire allocation process is closely centered around the reliability relationship between mission-related functions, breaking through the limitations of previous spacecraft allocations based on simple series connection of subsystems, and fully considering the configuration relationship between functions between subsystems and compartments. For details on the allocation process of assembly mission reliability indicators, see Figure 2 .

[0052] Usually, spacecraft products have inheritance requirements. For the situation where the new and old systems are similar and the old system has accumulated reliability statistical data, the proportional combination allocation method can be used to allocate the mission reliability index according to the proportion of the predicted failure probability. Its mathematical expression is:

[0053]

[0054] Where: - Failure rate indicator of the new system (1 / h);

[0055] - the failure rate assigned to the i-th subsystem in the new system (1 / h);

[0056] λ s老 - Failure rate of the old system (1 / h);

[0057] λ i老 -Failure rate of the i-th subsystem in the old system (1 / h).

[0058] Step three, use cross-vehicle reliability modeling and prediction methods to predict mission reliability indicators such as launch and autonomous flight missions, assembly and construction missions, propellant replenishment and extravehicular activity missions, and verify the coordination of mission reliability indicators assigned to functional systems and single machines to ensure that requirements are met in both mission time and functional logic dimensions.

[0059] Based on the indicator allocation results, reliability modeling and prediction are carried out for the second-tier tasks. The feasibility of system indicators and the correctness of indicator allocation are verified according to the predicted results to ensure indicator coordination. When predicting mission reliability, the impact of on-orbit maintenance on mission reliability needs to be considered and reflected in the modeling and prediction, including:

[0060] 1) Verify the feasibility of maintenance from two levels: the design of the single-machine mechanical, electrical, and hydraulic interfaces, as well as the system maintainability design. The single-machine maintenance analysis needs to confirm whether the product is an on-orbit replaceable unit, and whether the mechanical fasteners and electrical connectors can be quickly and safely disassembled and plugged in; the system-level maintainability analysis needs to confirm whether the oRU fault can be detected, located, and isolated, whether the overall layout supports visual accessibility, and whether the power supply and information system design supports fault isolation; on the basis of confirming that the maintenance is feasible, further analyze the support resource situation and confirm whether there are maintenance spare parts and maintenance operation tools on orbit; for regularly replaced products, confirm the matching of spare parts launch uplink planning and on-orbit life consumption; for extravehicular maintenance operation projects, confirm the extravehicular task arrangement.

[0061] 2) After passing the maintainability inspection, it can be seen that the on-orbit maintenance meets the characteristics of repair as new, and the mission time during reliability estimation is determined according to the maintenance strategy. In addition, there are spare parts stored on the orbit, which have been verified to be able to be repaired and replaced within the time allowed by the system, which is similar to the on-orbit cold backup. According to this principle, the series non-redundant functions and products in the original system are modified to be similar to the cold reserve model or voting model.

[0062] Step 4: According to the test results and the aircraft system optimization design method, adjust the function and hardware configuration plan, and adjust and optimize the function and hardware mission reliability indicators.

[0063] The integrated use of cross-vehicle functions and the storage of spare parts on orbit increase the system margin, which can improve the system function mission reliability index without changing or even appropriately reducing the single-machine mission reliability requirements; in addition, the equipment maintenance and replacement work can also meet the spacecraft life and mission requirements, providing space for further reducing the single-machine mission reliability index. Based on the multi-vehicle combined spacecraft optimization system design, through reliability modeling and expected iteration, reasonable and coordinated single-machine reliability indicators can be finally determined. The main indicator optimization methods include:

[0064] 1) Carry out on-orbit maintainability design of single-machine products and determine appropriate maintenance cycles;

[0065] 2) Determine the established maintenance cycle as the product task time;

[0066] 3) Determine whether to reserve spare parts on orbit or on the ground based on the product's redundancy, functional importance, and the urgency of the consequences of a failure;

[0067] 4) Model maintenance support measures such as maintenance cycles and spare parts reserves, approximate the maintainable products with spare parts reserves to cold reserves or voting models for prediction, and determine the mission reliability index of the final single-machine product based on the prediction results.

[0068] Step five is to form a mission reliability index system for multi-vehicle combination spacecraft, determine the connotation of each mission reliability index, clarify the requirements and methods of prediction, verification and evaluation, and guide reliability design work.

[0069] According to the above process, the system top-level mission-level reliability indicators are decomposed into long-term flight missions and short-term special missions, and the mission reliability indicators of each mission phase, each spacecraft, each subsystem of the spacecraft, and a single aircraft can be determined. On this basis, the timing of the generation of data samples that can be used for quantitative prediction and evaluation during the ground development and on-orbit flight of spacecraft products at all levels is comprehensively analyzed. Combined with the on-orbit mission profile, the timing and evaluation requirements of the quantitative prediction and evaluation of the second-level mission reliability indicators are determined, and the mission reliability indicator system of multi-spacecraft combined spacecraft is formed, as shown in Table 1.

[0070] The present invention fully studies the characteristics of the phased assembly and construction of multi-aircraft combined spacecraft, the intersection of autonomous flight missions and various special tasks, establishes a mission reliability index system from the aspects of mission function decomposition, top-level reliability index allocation, and reliability index coordination inspection, and proposes a reliability prediction method in combination with the application of the system. The scheme provided by the present invention can adapt to the mission reliability index system with the characteristics of the gradual combination of multiple aircraft, as well as the reasonable application of the index system in the allocation, prediction and evaluation of mission reliability indicators, which is helpful to realize the coordinated allocation of multi-stage mission reliability indicators, and obtain the quantitative evaluation results of the system mission reliability indicators under the premise of moderate scale and controllable cost of quantitative verification tests, thereby supporting risk point identification and mission decision-making.

[0071] Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of the present invention.

[0072]

[0073]

[0074]

Claims

1. A method for constructing a reliability index system for a multi-vehicle combined spacecraft, characterized in that: include: Analysis of the construction process and mission functions of multi-vehicle combined spacecraft, breaking down the total mission requirements into key flight events, single vehicles and specific functional systems from top to bottom for the combined spacecraft; Allocate the mission reliability index of the entire life cycle to each aircraft and each single equipment in each mission phase; Adopt cross-vehicle reliability modeling and prediction methods to predict the mission reliability indicators of launch and autonomous flight missions, assembly and construction missions, propellant replenishment and extravehicular activity missions, and verify the coordination of mission reliability indicators of functional systems and single-vehicle allocations to ensure that requirements are met in both mission time and functional logic dimensions; According to the test results and combined with the aircraft system optimization design method, adjust the function and hardware configuration plan, and adjust and optimize the function and hardware mission reliability indicators.

2. The method according to claim 1, characterized in that The decomposition of the overall mission requirements into key flight events, single aircraft and specific functional systems includes: The flight event assurance chain analysis combined with the probabilistic risk analysis (PRA) method is used to identify the initial events that lead to the failure of the top-level mission, conduct an independence analysis of the initial events, and determine the spacecraft's autonomous flight mission and the short-term special missions implemented on this basis, including rendezvous and docking missions, transfer missions, propellant replenishment missions, and extravehicular activity missions as the second-level missions; Analyze and determine the functional systems corresponding to completing the mission. The functional systems that ensure the platform's autonomous flight mission include the platform's functional systems for structural bearing and sealing, power supply and distribution, information management, control and propulsion, thermal management, and manned environment control; the functional systems that ensure special missions include the mission functional systems for rendezvous and docking, transfer, propellant replenishment, extravehicular activities, and payload test support.

3. The method according to claim 1, characterized in that The allocation of the life cycle mission reliability index to each aircraft and each stand-alone equipment in each mission phase includes: For the top-level life and reliability indicators, indicators are allocated based on the multi-aircraft assembly as a whole; first, in comparison with the aforementioned mission function analysis, the system mission reliability indicators are allocated to the assembly's platform functions of structural bearing and sealing, power supply and distribution, information management, control and propulsion, thermal management, and manned environment control, as well as rendezvous and docking, transfer, propellant replenishment, extravehicular activities, and load test support; secondly, based on the configuration of the assembly's related functions in each compartment and in accordance with the redundancy relationship within the aircraft and between aircraft, the reliability indicators of each function of the assembly are allocated to the corresponding functions of the specific compartment; finally, they are allocated to the specific hardware products in the specific compartment.

4. The method according to claim 3, characterized in that The proportional combination allocation method is used to allocate the task reliability index to the new and old systems according to the proportion of the predicted failure probability; its mathematical expression is: Where: —Failure rate indicator of the new system (1 / h); —failure rate assigned to the i-th subsystem in the new system (1 / h); λ s老 —Failure rate of old system (1 / h); λ i老 —Failure rate of the i-th subsystem in the old system (1 / h).

5. The method according to claim 1, characterized in that The coordination of the reliability indicators of the task assigned by the inspection function system and the single machine is ensured to meet the requirements in both the task time dimension and the functional logic dimension, including: Verify the feasibility of maintenance from two levels: single-machine mechanical, electrical, and fluid interface design, as well as system maintainability design. Single-machine-level maintenance analysis confirms whether the product is an on-orbit replaceable unit (ORU), and whether the mechanical fasteners and electrical connectors can be quickly and safely removed and plugged in. System-level maintainability analysis confirms whether ORU faults can be detected, located, and isolated, whether the overall layout supports visual accessibility, and whether the power supply and information system design supports fault isolation. On the basis of confirming that the maintenance is feasible, further analyze the support resource situation to confirm whether there are maintenance spare parts and maintenance operation tools on orbit. For regularly replaced products, confirm the matching of spare parts launch uplink planning and on-orbit life consumption. For extravehicular maintenance operation projects, confirm the extravehicular mission arrangements.

6. The method according to claim 5, characterized in that Through maintainability inspection, it is determined that on-orbit maintenance meets the requirements of repair-as-new, and the mission time during reliability prediction is determined according to the maintenance strategy; if spare parts are stored on-orbit and it is verified that the repair and replacement can be completed within the time allowed by the system, it is confirmed as an on-orbit cold backup, thereby correcting the series non-redundant functions and products in the original system to a cold reserve model or voting model.

7. The method according to claim 1, characterized in that The above-mentioned adjusting the function and hardware configuration scheme according to the inspection results and combining the aircraft system optimization design method, adjusting and optimizing the function and hardware mission reliability index, includes: Based on the design of multi-vehicle combined spacecraft optimization system, reasonable and coordinated single-machine reliability indicators can be finally determined through reliability modeling and prediction iteration; the indicator optimization methods include: Carry out on-orbit maintainability design of single-unit products and determine appropriate maintenance cycles; Determine the established maintenance cycle as the product task time; Determine whether to reserve spare parts on orbit or on the ground based on the product's redundancy, functional importance, and the urgency of the consequences of a failure; The maintenance cycle and maintenance support measures of reserve spare parts are modeled, and the maintainable products with reserve spare parts are approximated as cold reserves or voting models for prediction. The mission reliability index of the final single-machine product is determined based on the prediction results.

8. The method according to claim 1, characterized in that: The method further comprises: Form a mission reliability index system for multi-vehicle combined spacecraft.

9. The method according to claim 8, characterized in that The mission reliability index system for forming a multi-vehicle combined spacecraft includes: Complete the decomposition of the system's top-level mission-level reliability indicators into long-duration flight missions and short-duration special missions, and determine the mission reliability indicators of each mission phase, each aircraft, each aircraft subsystem, and a single aircraft; A comprehensive analysis is conducted on the timing of generating data samples that can be used for quantitative prediction and evaluation during the ground-based development and on-orbit flight of various levels of spacecraft products. Combined with the on-orbit mission profile, the timing and requirements for quantitative prediction and evaluation of the second-tier mission reliability indicators are determined to form a mission reliability indicator system for multi-vehicle combination spacecraft.

10. The method according to claim 9, characterized in that The mission reliability index system of the multi-vehicle combined spacecraft includes: During the single-cabin flight phase, the system mission reliability indicators include the autonomous flight mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, and control and propulsion mission reliability of cabin A; the system mission reliability indicators also include the propellant replenishment support mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the propulsion replenishment functional mission reliability of cabin A; the system mission reliability indicators also include the astronaut and cargo transportation support mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the rendezvous and docking functional mission reliability of cabin A; the system mission reliability indicators also include the extravehicular activity support mission reliability of cabin A, and the corresponding functional / subsystem reliability indicators include the reliability of the robotic arm and extravehicular support functional mission of cabin A; During the assembly and construction stage, the system mission reliability indicators include the autonomous flight mission reliability of the B compartment, and the corresponding functional / subsystem reliability indicators include the structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, and control and propulsion mission reliability of the B compartment; the system mission reliability indicators also include the docking and transfer mission reliability of the B compartment, and the corresponding functional / subsystem reliability indicators include the rendezvous and docking functional mission reliability of the B compartment; the system mission reliability indicators also include the assembly and construction mission reliability of the A compartment + B compartment combination, and the corresponding functional / subsystem reliability indicators include the transfer functional mission reliability of the A and B compartments; the system mission reliability indicators also include the autonomous flight mission reliability of the A compartment + B compartment combination, and the corresponding functional / subsystem reliability indicators include the A compartment + B compartment combination Structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, control and propulsion mission reliability; system mission reliability indicators also include autonomous flight mission reliability of C compartment, and the corresponding functional / subsystem reliability indicators include structural mission reliability, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, control and propulsion mission reliability of C compartment; system mission reliability indicators also include docking and transfer mission reliability of C compartment, and the corresponding functional / subsystem reliability indicators include rendezvous and docking functional mission reliability of C compartment; system mission reliability indicators also include assembly and construction mission reliability distribution of A compartment + B compartment + C compartment, and the corresponding functional / subsystem reliability indicators include A+B compartment and C compartment transfer functional mission reliability; During the assembly and construction phase and the operation phase, the system mission reliability indicators include the autonomous flight mission reliability of the three-cabin combination, and the corresponding function / subsystem reliability indicators include the structural mission reliability of the A-cabin + B-cabin + C-cabin combination, power supply and distribution mission reliability, thermal management mission reliability, manned environment control mission reliability, information management mission reliability, and control and propulsion mission reliability; During the operation phase, for the completed combination, the system mission reliability indicators include the propellant replenishment support mission reliability, and the corresponding function / subsystem reliability indicators include the propulsion replenishment function mission reliability of the A-module + B-module + C-module combination; the system mission reliability indicators also include the astronaut and cargo transportation support mission reliability, and the corresponding function / subsystem reliability indicators include the propulsion replenishment function mission reliability of the A-module + B-module + C-module combination; the system mission reliability indicators also include the extravehicular activity support mission reliability, and the corresponding function / subsystem reliability indicators include the rendezvous and docking function mission reliability of the A-module + B-module + C-module combination.

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