Parameter evaluation method for characterizing satellite reliability, maintainability and supportability comprehensive capabilities

Abstract

The present invention discloses a parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and security, including: step 1, performing fault mode analysis to determine a fault list; wherein the fault mode list includes: fault name, failure rate, and fault on-orbit maintenance measures; step 2, establishing a satellite use availability model according to user mission requirements and satellite system composition; step 3, estimating the probability of functional interruption caused by equipment-level failure rate and space environment; step 4, estimating satellite maintenance time parameters; step 5, calculating satellite use availability. The present invention establishes the corresponding relationship and prediction method between user-level parameters and system, subsystem, and single-machine-level parameters as the basis for RMS design of satellite products at all levels, aiming to solve the problem of disconnection between user requirements for satellite RMS comprehensive parameters and satellite design parameter requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite parameter modeling and prediction, and in particular relates to a parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and security. Background Art

[0002] At present, the RMS-related indicators of satellite products are mainly lifespan and reliability. Satellite systems, subsystems, single machines and even components all have clear reliability indicator requirements. However, satellite RMS design element indicators such as maintainability, testability, and adaptability to the space environment are lacking, especially the comprehensive parameters that reflect the satellite's ability to complete business. The current reliability indicators are mainly design indicators, which aim to guide the reliability design of satellite products at all levels, and lack application indicators for users and specific businesses. Therefore, in addition to reliability, it is very necessary to build a new set of satellite product RMS parameter system to evaluate the comprehensive capabilities of satellites. Summary of the invention

[0003] The technology of the present invention solves the following problems: overcomes the deficiencies of the prior art, provides a parameter evaluation method for characterizing the comprehensive capabilities of satellite reliability, maintainability and security, aims to solve the problem of disconnection between users' requirements for satellite RMS comprehensive parameters and satellite design parameter requirements, establishes the correspondence and prediction method between user-layer parameters and system, subsystem and single-machine level parameters, and serves as the basis for RMS design of satellite products at all levels.

[0004] In order to solve the above technical problems, the present invention discloses a parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, including:

[0005] Step 1: Perform a failure mode analysis and determine a failure list; wherein the failure mode list includes: failure name, failure rate, and on-orbit maintenance measures for the failure;

[0006] Step 2: Establish a satellite availability model based on user mission requirements and satellite system composition;

[0007] Step 3: estimate the probability of functional interruption caused by equipment-level failure rate and space environment;

[0008] Step 4, estimate satellite maintenance time parameters;

[0009] Step 5: Calculate the satellite availability.

[0010] In the above parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, a failure mode analysis is performed to determine the failure list, including:

[0011] Sub-step 11, according to the system tasks and functions, determine the system functional hierarchy through functional analysis, that is, decompose the system tasks into related functions, and decompose the functions from the system level step by step, and expand them downward step by step to draw a functional hierarchy diagram;

[0012] Sub-step 12, according to the determined system functional level, clarify the equipment failure mode, failure repair method, and list the failure mode of each device.

[0013] In the above parameter evaluation method that characterizes the comprehensive capability of satellite reliability, maintainability and supportability, the satellite availability model is expressed as follows:

[0014]

[0015]

[0016] Among them, A0 represents the availability; T BF represents the mean time between failures, which is determined by the failure rate of each single product and the probability of functional interruption caused by the space environment; R M Represents task reliability; L SE Indicates the working life requirement; M CT Indicates the average repair time of satellite systems and subsystems; T OR and T ORF P represents the average repair time of satellite system and subsystem for ground remote control redundant system switching and on-orbit autonomous recovery of related faults respectively; STU is the probability of functional interruption caused by the space environment; P STUi , P STU-ORj , P STU-ORFk are the probability of failures caused by comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery related to space environment events; λ i ,λ ORj ,λ ORFk represent the failure rates of comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery of related faults; T CT It represents the average fault repair time of a single product; T CTi , T CT-ORj , T CT-ORFk They respectively represent the average repair time for related faults including comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery.

[0017] In the above parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, the estimated equipment-level failure rate and the probability of functional interruption caused by the space environment include:

[0018] Sub-step 31, estimating the failure rate of on-orbit faults: estimating the failure rate of each fault item by item according to the fault list determined in step 1;

[0019] Sub-step 32, prediction of the probability of functional interruption caused by the space environment due to on-orbit faults: Based on the fault list determined in step 1, the interruption probability of the space environment related fault mode is predicted.

[0020] In the above parameter evaluation method that characterizes the comprehensive capability of satellite reliability, maintainability and supportability, the probability of functional interruption caused by the space environment of on-orbit failure is carried out for FPGA devices. The calculation formula of the functional interruption rate P of FPGA devices is as follows:

[0021] P=P1×P2×P3+P4×P5×P6+P7×P8×P9+P10

[0022] Among them, P1 represents the flip rate of the configuration memory, P2 represents the utilization rate of the resources of the circuit system or core module, P3 represents the conversion rate of the configuration memory, P4 represents the flip rate of the block memory, P5 represents the resource utilization rate of the block memory, P6 represents the conversion rate of the block memory, P7 represents the flip rate of the CLB trigger, P8 represents the resource utilization rate of the circuit system or core module CLB, P9 represents the conversion rate of the CLB trigger, and P10 represents the probability of interruption of the device space environment function.

[0023] In the above parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, the functional abnormality rate of all relevant FPGA devices is obtained by using the on-orbit data prediction method of similar devices:

[0024] a) Calculate the flip rate of the FPGA device under mission orbit environment conditions and considering resource usage:

[0025] Obtain the intrinsic flip rate of the FPGA device, including: the storage area flip rate P under the target orbit environment bR1 , Configuration area flip rate P bS1 ;

[0026] According to the resource occupancy of the FPGA device storage area and configuration area, determine the storage area resource occupancy coefficient β RR1 and configuration area resource occupancy coefficient β RS1 , and then the flip rate P after the FPGA device resource usage is obtained M1 for:

[0027] P M1 =P bS1 *β RS1 +P bR1 *β RR1

[0028] b) Using data from similar FPGA devices, calculate the frequency of functional anomalies of the current FPGA device on orbit due to soft errors in the space environment without taking protective measures:

[0029] Obtain the frequency P of functional abnormality caused by soft errors in the space environment of similar FPGA devices under unprotected conditions on orbit F2 ;

[0030] Calculate the toggle rate P of similar FPGA devices after considering resource usage M2 , and then compare the structural complexity of the current FPGA device and similar FPGA devices to determine the structural complexity coefficient β c , thus obtaining the frequency P of functional abnormality caused by soft errors in the space environment in the current FPGA device on orbit without taking protective measures F1 for:

[0031] P F1 =P F2 *β c =P F2 *(P M1 / P M2 )

[0032] c) Using the data of the same type of FPGA device, calculate the current FPGA device function abnormality rate:

[0033] Determine the protection factor β based on the effect comparison data of the same type of FPGA device before and after taking space environment protection measures P ;

[0034] The abnormal rate P0 of the current FPGA space environment function is obtained as follows:

[0035] P0=P F1 / β P

[0036] d) After obtaining the component flip probability, the functional interruption probability index caused by the spatial environment of the corresponding fault mode can be obtained by referring to the failure rate prediction model based on the device usage and the series and parallel relationship of the modules and single machines.

[0037] In the above parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, the estimated satellite maintenance time parameters include:

[0038] Sub-step 41, determining maintenance activities and repair time elements; wherein maintenance activities include: fault location, fault isolation, command generation, command sending and execution, and status confirmation; repair time elements include: fault location time T 1anj , Fault isolation time T 1bnj , instruction generation time T 2nj , instruction sending and execution time T 3nj and status confirmation time T 4nj ;

[0039] Sub-step 42, constructing a maintainability prediction model; wherein the maintainability prediction model includes: average on-orbit reconstruction time T OR The estimated model and average on-orbit autonomous recovery time T ORF The prediction model;

[0040] Sub-step 43, taking a single device as a unit, based on the maintainability prediction model, satellite maintenance time parameter prediction is performed.

[0041] In the above parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability,

[0042] Average on-orbit reconstruction time T OR The prediction model is expressed as follows:

[0043]

[0044] Where N represents the number of replaceable units RI, λ n represents the failure rate of the nth RI, T n represents the average on-orbit reconstruction time of the nth RI;

[0045]

[0046] Where J represents the total number of faults that can be detected by the nth RI on-orbit and handled by ground remote control, λ n represents the failure rate of the jth failure mode of the nth RI, T nj represents the fault repair time of the jth fault mode of the nth RI;

[0047]

[0048] Among them, M nj represents the number of maintenance activities when the jth failure mode of the nth RI is repaired, T mnj It represents the average time to perform the mth maintenance activity for the jth failure mode of the nth RI;

[0049] Average on-orbit function autonomous recovery time T ORF The prediction model is expressed as follows:

[0050]

[0051] Among them, T n ′ represents the average on-orbit autonomous functional recovery time of the nth RI;

[0052]

[0053] Where J′ represents the total number of faults that can be detected and autonomously recovered on-orbit by the nth RI.

[0054] In the above parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, satellite maintenance time parameter prediction is performed based on the maintainability prediction model with a single device as the unit, including:

[0055] Based on the fault list determined in step 1, for each fault mode, according to the specific maintenance plan of each fault mode, estimate each repair time element specified in step 4.1 item by item to obtain the equipment data collection table;

[0056] According to the equipment data collection table, data is summarized to obtain a summary data table;

[0057] According to the summary data in the summary data, select the corresponding maintainability prediction model given in step 4.2 and solve to obtain the satellite maintenance time parameter prediction results.

[0058] In the above parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, the satellite availability is calculated, including:

[0059] Based on the predicted results of the equipment-level failure rate and the probability of functional interruption caused by the space environment in step 3 and the predicted results of the satellite maintenance time parameters in step 4, complete the fault list of the relevant equipment listed in step 1, and use the satellite availability model to calculate and obtain the satellite availability.

[0060] The present invention has the following advantages:

[0061] (1) The present invention discloses a parameter evaluation method for characterizing the comprehensive capabilities of satellite reliability, maintainability and supportability, which solves the problem that the satellite RMS index is relatively single, especially the lack of user application index and comprehensive index.

[0062] (2) The present invention discloses a parameter evaluation method for characterizing the comprehensive capabilities of satellite reliability, maintainability and security, and establishes a model relationship between user application indicators and individual design indicators such as system, subsystem and single-machine equipment reliability, maintainability and testability, which can effectively convert the design parameters of each layer of products into the system's usable capabilities.

[0063] (3) The present invention discloses a parameter evaluation method for characterizing the comprehensive capabilities of satellite reliability, maintainability and security. The proposed RMS comprehensive parameters have a unified theoretical basis with the RMS comprehensive parameters of other products, and can provide parameter support for the subsequent inclusion of satellites into the large-scale space-ground system for system performance analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a flow chart of the steps of a parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability in an embodiment of the present invention;

[0065] Figure 2 It is a schematic diagram of the corresponding relationship between the comprehensive RMS parameters at the user layer and the individual RMS design parameters at the system, subsystem and single-machine device layers in an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0067] Through relevant foreign research and preliminary work, under the framework of following the basic definition of RMS comprehensive parameters, combined with the satellite field product business and actual operation characteristics. It is proposed that the degree to which the product is in a working or usable state when it is needed and starts to perform tasks at any random time is called the availability of satellite products, and the probability measurement of availability is availability. Commonly used availability parameters include inherent availability, achievable availability and operational availability. For satellite equipment, due to the characteristics of its maintenance and support system, the concept of operational availability is adopted, and the following method can be used for measurement: the ratio of the mean time between failures of the product to the sum of the mean time between failures and the mean repair time. Based on this, the present invention proposes a parameter evaluation method for characterizing the comprehensive capabilities of satellite reliability, maintainability and supportability, and implements the user-oriented RMS comprehensive parameters step by step into the RMS single design indicators such as system, subsystem, and single machine reliability, maintainability, and space environment adaptability, establishes an RMS comprehensive parameter model, and focuses on providing a prediction method for the maintainability and space environment adaptability indicators with satellite characteristics to guide the RMS design of satellite products.

[0068] like Figure 1 and Figure 2 In this embodiment, the parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability includes:

[0069] Step 1: Perform failure mode analysis and determine the failure list

[0070] Sub-step 11, according to the system tasks and functions, determine the system functional hierarchy through functional analysis, that is, decompose the system tasks into related functions, and decompose the functions from the system level step by step, and expand them downward step by step to draw a functional hierarchy diagram.

[0071] Sub-step 12, according to the determined system function level, clarify the equipment failure mode, failure repair method, and list the failure mode of each equipment. The failure mode list includes but is not limited to: failure name, failure rate, and on-orbit repair measures.

[0072] Step 2: Establish a satellite availability model based on user mission requirements and satellite system composition.

[0073] In this embodiment, the satellite usage availability model is expressed as follows:

[0074]

[0075]

[0076] Among them, A0 represents the availability; T BF represents the mean time between failures, which is determined by the failure rate of each single product and the probability of functional interruption caused by the space environment; R M Represents task reliability; L SE Indicates the working life requirement; M CT Indicates the average repair time of satellite systems and subsystems; T OR and T ORF P represents the average repair time of satellite system and subsystem for ground remote control redundant system switching and on-orbit autonomous recovery of related faults respectively; STU is the probability of functional interruption caused by the space environment; P STUi , P STU-ORj , P STU-ORFk are the probability of failures caused by comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery related to space environment events; λ i ,λ ORj ,λ ORFk represent the failure rates of comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery of related faults; T CT It represents the average fault repair time of a single product; T CTi , T CT-ORj , T CT-ORFk They respectively represent the average repair time for related faults including comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery.

[0077] Step 3: Estimate the equipment-level failure rate and the probability of functional interruption caused by the space environment.

[0078] Sub-step 31, on-orbit failure rate estimation: According to the failure list determined in step 1, the failure rate of each failure is estimated item by item. The failure rate estimation can be performed with reference to relevant standards.

[0079] Sub-step 32, prediction of the probability of functional interruption caused by the space environment of on-orbit faults: Based on the fault list determined in step 1, the interruption probability of the space environment related fault mode is predicted. This type of fault is mainly carried out for FPGA devices.

[0080] The FPGA device function anomaly rate is related to the device's intrinsic flip rate, as well as orbital conditions, device resource usage, space environment protection design, etc. At present, the common method is to conduct ground irradiation tests or fault injection simulations to obtain data on the space environment function anomaly rate. For devices with complete tests and simulations, test or simulation data can be directly used.

[0081] The calculation formula of the functional interruption rate P of the FPGA device is as follows:

[0082] P=P1×P2×P3+P4×P5×P6+P7×P8×P9+P10

[0083] Among them, P1 represents the flip rate of the configuration memory, P2 represents the utilization rate of the resources of the circuit system or core module, P3 represents the conversion rate of the configuration memory, P4 represents the flip rate of the block memory, P5 represents the resource utilization rate of the block memory, P6 represents the conversion rate of the block memory, P7 represents the flip rate of the CLB trigger, P8 represents the resource utilization rate of the circuit system or core module CLB, P9 represents the conversion rate of the CLB trigger, and P10 represents the probability of functional interruption in the device space environment. The conversion rate refers to the proportion of logic that can affect the system function, because not all flips will cause system function interruption.

[0084] Since ground irradiation tests require a large investment, the test results generally do not represent the actual situation on orbit, the fault injection simulation cycle is long, and it depends on the accuracy of the model, they have not been widely used. In order to quickly and effectively obtain the functional abnormality rate of all relevant FPGA devices, a similar device on-orbit data prediction method can be used:

[0085] a) Calculate the flip rate of the FPGA device under mission orbit environment conditions and considering resource usage:

[0086] First, the intrinsic flip rate of the FPGA device is obtained, including: the storage area flip rate P under the target orbit environment bR1 , Configuration area flip rate P bS1 ; Then, according to the resource occupancy of the storage area and configuration area of ​​the FPGA device, determine the storage area resource occupancy coefficient β RR1 and configuration area resource occupancy coefficient β RS1 , and then the flip rate P after the FPGA device resource usage is obtained M1 for:

[0087] P M1 =P bS1 *β RS1 +P bR1 *β RR1

[0088] The resource occupancy factor is the ratio of occupied resources to device resources.

[0089] b) Using data from similar FPGA devices, calculate the frequency of functional anomalies of the current FPGA device on orbit due to soft errors in the space environment without taking protective measures:

[0090] First, the frequency P of functional abnormality caused by soft errors in the space environment of similar FPGA devices without protection on orbit is obtained. F2 ; Then, calculate the flip rate P of similar FPGA devices after considering resource usage M2 , and then compare the structural complexity of the current FPGA device and similar FPGA devices to determine the structural complexity coefficient β c , thus obtaining the frequency P of functional abnormality caused by soft errors in the space environment in the current FPGA device on orbit without taking protective measures F1 for:

[0091] P F1 =P F2 *β c =P F2 *(P M1 / P M2 )

[0092] c) Using the data of the same type of FPGA device, calculate the current FPGA device function abnormality rate:

[0093] First, the protection factor β is determined based on the effect comparison data of the same type of FPGA device before and after taking space environment protection measures. P ; Then, the abnormal rate P0 of the current FPGA space environment function is obtained as:

[0094] P0=P F1 / β P

[0095] Among them, the protection factor β P That is, the ratio of the error rate before and after taking measures.

[0096] d) After obtaining the component flip probability, the functional interruption probability index caused by the spatial environment of the corresponding fault mode can be obtained by referring to the failure rate prediction model based on the device usage and the series and parallel relationship of the modules and single machines.

[0097] Step 4: Estimated satellite maintenance time parameters.

[0098] Sub-step 41, determining the maintenance activities and repair time elements.

[0099] Maintainability is mainly estimated for corrective maintenance, and the maintainability parameter is the average on-orbit reconstruction time (redundant system switching time) TOR and the average on-orbit function autonomous recovery time T ORF , which can be divided into the following maintenance activities:

[0100] Fault location: The fault location can be determined without using auxiliary test equipment, that is, only through satellite on-orbit telemetry, without the help of ground designers;

[0101] Fault isolation: Use auxiliary test equipment or means to determine the fault location, mainly refers to the analysis and determination of the fault location by ground design personnel;

[0102] Instruction generation: The process of determining the on-orbit maintenance strategy and forming executable instructions for the controlled unit based on the fault telemetry information and the predetermined procedure or on-orbit fault plan;

[0103] Command sending and execution: The process in which the main control unit or ground control system sends the fault repair command to the controlled unit and the controlled unit executes the command;

[0104] Status confirmation: Telemetry monitoring activities performed to verify that backup equipment is functioning properly.

[0105] Furthermore, the time required for the above maintenance activities is called the repair time element. The definitions and symbols of these repair time elements used in the prediction model are as follows:

[0106] Fault location time T 1anj : The time taken to carry out fault location activities;

[0107] Fault isolation time T 1bnj : The time taken to carry out fault isolation activities;

[0108] Instruction generation time T 2nj : The time required to carry out instruction generation activities after the fault location is determined;

[0109] Instruction sending and execution time T 3nj : After the fault recovery instruction is determined, the instruction is sent to the controlled unit. The total time for the controlled unit to execute the controlled instruction includes the instruction sending time, the interval time between instructions and the instruction formulation time;

[0110] Status confirmation time T 4nj : After the controlled unit's command is executed, the time to confirm whether the backup unit is working normally is based on the backup unit's telemetry parameters.

[0111] The subscript "nj" indicates the maintenance work of the jth failure mode of the nth replaceable unit RI (satellite generally refers to the backup unit).

[0112] Sub-step 42: constructing a maintainability prediction model.

[0113] The maintainability prediction model can specifically include: average on-orbit reconstruction time T OR The estimated model and average on-orbit autonomous recovery time T ORF prediction model.

[0114] Average on-orbit reconstruction time T OR The prediction model is expressed as follows:

[0115]

[0116] Where N represents the number of replaceable units RI, λ n represents the failure rate of the nth RI, T n represents the average on-orbit reconstruction time of the nth RI; J represents the total number of faults that can be detected on-orbit and handled by ground remote control for the nth RI, λ n represents the failure rate of the jth failure mode of the nth RI, T nj It represents the fault repair time of the jth fault mode of the nth RI.

[0117] Average on-orbit function autonomous recovery time T ORF The prediction model is expressed as follows:

[0118]

[0119] Among them, T n ′ represents the average on-orbit autonomous function recovery time of the nth RI; J′ represents the total number of faults that can be detected and autonomously recovered by the nth RI on-orbit.

[0120]

[0121] Among them, M nj represents the number of maintenance activities when the jth failure mode of the nth RI is repaired, T mnj It represents the average time to perform the mth maintenance activity for the jth failure mode of the nth RI.

[0122] Sub-step 43, taking a single device as a unit, based on the maintainability prediction model, satellite maintenance time parameter prediction is performed.

[0123] First, based on the fault list determined in step 1, for each fault mode, according to the specific maintenance plan of each fault mode, each repair time element specified in step 4.1 is estimated item by item to obtain the equipment data collection table, as shown in Table 1:

[0124]

[0125] Table 1, Equipment data collection table

[0126] Note: In the first column, "RI Name", fill in the name of the backup unit that is expected to be involved in this operation; in the second column, "Parameter Name", fill in the maintainability parameter that is expected in this operation, which should generally be the average on-orbit reconstruction time (redundant system switching time) T OR Or the average on-orbit function autonomous recovery time T ORF Column 3 "Fault Description": Fill in the relevant fault mode information of the backup unit in the column; Column 4 "Maintenance Activity Description": Fill in the maintenance strategy corresponding to the fault mode in the column, generally fill in the name of the corresponding fault plan; Column 5 "Fault Rate λ j ": Fill in the failure rate of the corresponding failure mode in the column; Columns 6, 7, 8, 9 and 10: These items are the time of each maintenance activity, and column 10 is the sum of columns 6, 7, 8 and 9; Column 11 "λ j T m ”: Fill in the 5th column “Failure rate λ j ” and column 10 “T m " is the product of .

[0127] Then, according to the equipment data collection table, the data is summarized to obtain a summary data table, as shown in Table 2:

[0128]

[0129] Table 2, Maintenance time parameter estimation table

[0130] Note: In the first column, "Project", fill in the task or system function that is expected to be targeted this time; in the second column, "Parameter Name", fill in the maintainability parameter that is expected this time, which should generally be the average on-orbit reconstruction time (redundant system switching time) T OR Or the average on-orbit function autonomous recovery time T ORF Column 3 "RI Name": Fill in the name of the backup unit expected to be involved in this column; Column 4 "Failure Rate λ n ": Fill in the corresponding RI related failure rate in the column, which can be obtained through the "Equipment Data Collection Form"; Column 5 "Equipment Maintenance Time T n ": Fill in the evaluation repair time of the corresponding RI related fault in the column, which can be obtained through the "Equipment Data Collection Form"; Column 6 "λ n T n ”: Fill in the 4th column “Failure rate λ n ” and Column 5 “Equipment maintenance time T n " is the product of .

[0131] Finally, according to the summary data in the summary data, the corresponding maintainability prediction model given in step 4.2 is selected to solve and obtain the satellite maintenance time parameter prediction results.

[0132] Step 5: Calculate the satellite availability.

[0133] In this embodiment, based on the predicted results of the probability of functional interruption caused by the equipment-level failure rate and the space environment in step 3 and the predicted results of the satellite maintenance time parameters in step 4, the fault list of the relevant equipment listed in step 1 is completed, and the satellite availability model is used for calculation to obtain the satellite availability.

[0134] Based on the above embodiment, a specific example is given below for explanation.

[0135] Step 1: Determine the specific subsystems and equipment involved in the satellite's specific business

[0136] Taking a satellite function as an example, we conduct functional analysis. This function involves three satellite subsystems and seven single devices. By analyzing the failure modes of single devices, we can identify the failure modes of the equipment, the failure repair methods and specific repair measures, and list the failure modes of each related device, as shown in Table 3:

[0137]

[0138]

[0139] Table 3, List of failure modes of single equipment

[0140] Step 2: Establish a satellite availability model based on user mission requirements and satellite system composition.

[0141] The satellite usage availability model is expressed as follows:

[0142]

[0143]

[0144] Step three: Estimate the probability of functional interruption caused by equipment-level failure rate and space environment.

[0145] Step 3.1: Prediction of on-orbit failure rate;

[0146] According to the list of failure modes compiled in step 1, estimate the failure rate item by item and fill in the sixth column of Table 3, see Table 4:

[0147]

[0148]

[0149] Table 4, List of failure modes of single equipment (supplemental failure rate data)

[0150] Step 3.2: Estimate the probability of functional interruption caused by the space environment due to on-orbit failure of relevant products.

[0151] According to the list of failure modes compiled in step 1, the interruption probability of the failure modes related to the space environment is estimated. Table 5 below gives the on-orbit flip rate data of some devices:

[0152]

[0153] Table 5, the probability of interruption of the spatial environment function of some components. The interruption probability after completion is expected to be filled in the 8th column of Table 3, see Table 6 below:

[0154]

[0155]

[0156] Table 6, List of failure modes of single equipment (supplemental space environment function interruption probability)

[0157] Step 4: Satellite maintenance time parameter estimation

[0158] Take the single equipment as the unit, and estimate the maintenance time parameters. Based on the list of fault modes obtained in step 1, for each fault mode, according to its specific maintenance plan, estimate each repair time element specified in step 4.1 item by item. Tables 7 to 10 below give the satellite data estimation tables for single equipment 1 and single equipment 2 respectively:

[0159]

[0160] Table 7, Single machine 1 maintenance time data collection table 1

[0161]

[0162] Table 8, Single machine 1 maintenance time data collection table 2

[0163]

[0164] Table 9, Single machine 2 maintenance time data collection table 1

[0165]

[0166]

[0167] Table 10, Single machine 2 maintenance time data collection table 2

[0168] Use the above method to complete the maintenance time element estimate of each other single machine in Table 3, and fill in the maintenance time data collection table for each single machine according to the format in the above table.

[0169] After completing the above steps, summarize the data according to Tables 11 to 12 below:

[0170]

[0171] Table 11, Maintenance time parameter estimation table

[0172]

[0173] Table 12, Maintenance time parameter estimation table

[0174] According to the summary data given in Tables 11 and 12 above, the corresponding parameter prediction model given in step 4.2 can be selected to calculate the average on-orbit reconstruction time (redundant system switching time) T OR Or the average on-orbit function autonomous recovery time T ORF Expected results:

[0175] T OR =1.93 -07 / 7.28 -06 =0.0265

[0176] T ORF =4.87 -08 / 1.07 -05 =4.55 -03

[0177] T CTi The average repair time for comprehensive treatment is generally a few days to a few weeks for complex faults without backup measures or not identified in the design phase. It is difficult to accurately predict during the design process and can only be obtained by applying the evaluation method of past cases. In this example, the estimated recovery time for fault mode 20 in Table 3 is 168h.

[0178] Step 5: Calculate the satellite availability index.

[0179] According to the estimated results of the failure rate in step 3 and the probability of functional interruption caused by the space environment, complete the list of failure modes of the relevant equipment listed in step 1, see Table 13:

[0180]

[0181] Table 13, Calculation results of relevant parameters

[0182] According to the fault data in Table 13 and the estimated maintenance time results in step 4, calculations are performed to obtain the satellite availability results:

[0183]

[0184] Although the present invention has been 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 to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0185] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability, characterized in that: include: Step 1: Perform a failure mode analysis and determine a failure list; wherein the failure mode list includes: failure name, failure rate, and on-orbit maintenance measures for the failure; Step 2: Establish a satellite availability model based on user mission requirements and satellite system composition; Step 3: estimate the probability of functional interruption caused by equipment-level failure rate and space environment; Step 4, estimate satellite maintenance time parameters; Step 5, calculating the satellite availability; Perform a failure mode analysis to identify a list of failures, including: Sub-step 11, according to the system tasks and functions, determine the system functional hierarchy through functional analysis, that is, decompose the system tasks into related functions, and decompose the functions from the system level step by step, and expand them downward step by step to draw a functional hierarchy diagram; Sub-step 12, according to the determined system functional level, clarify the failure mode of the equipment, the failure repair method, and list the failure mode of each equipment; The satellite usage availability model is expressed as follows: Among them, A0 represents the availability; T BF represents the mean time between failures, which is determined by the failure rate of each single product and the probability of functional interruption caused by the space environment; R M Represents task reliability; L SE Indicates the working life requirement; M CT Indicates the average repair time of satellite systems and subsystems; T OR and T ORF P represents the average repair time of satellite system and subsystem for ground remote control redundant system switching and on-orbit autonomous recovery of related faults respectively; STU is the probability of functional interruption caused by the space environment; P STUi , P STU-ORj , P STU-ORFk are the probability of failures caused by comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery related to space environment events; λ i ,λ ORj ,λ ORFk represent the failure rates of comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery of related faults; T CT It represents the average fault repair time of a single product; T CTi , T CT-ORj , T CT-ORFk They respectively represent the average repair time for related faults including comprehensive treatment, ground remote control redundant system switching, and on-orbit autonomous recovery.

2. The parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability according to claim 1 is characterized in that: Estimated equipment-level failure rate and probability of functional interruption caused by space environment, including: Sub-step 31, estimating the failure rate of on-orbit faults: estimating the failure rate of each fault item by item according to the fault list determined in step 1; Sub-step 32, prediction of the probability of functional interruption caused by the space environment due to on-orbit faults: Based on the fault list determined in step 1, the interruption probability of the space environment related fault mode is predicted.

3. The parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability according to claim 2 is characterized in that: The probability of functional interruption caused by the space environment of on-orbit failures is carried out for FPGA devices. The calculation formula of the functional interruption rate P of FPGA devices is as follows: P=P1×P2×P3+P4×P5×P6+P7×P8×P9+P10 Among them, P1 represents the flip rate of the configuration memory, P2 represents the utilization rate of the resources of the circuit system or core module, P3 represents the conversion rate of the configuration memory, P4 represents the flip rate of the block memory, P5 represents the resource utilization rate of the block memory, P6 represents the conversion rate of the block memory, P7 represents the flip rate of the CLB trigger, P8 represents the resource utilization rate of the circuit system or core module CLB, P9 represents the conversion rate of the CLB trigger, and P10 represents the probability of interruption of the device space environment function.

4. The parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability according to claim 2 is characterized in that: Estimated satellite maintenance time parameters, including: Sub-step 41, determining maintenance activities and repair time elements; wherein maintenance activities include: fault location, fault isolation, command generation, command sending and execution, and status confirmation; repair time elements include: fault location time T 1anj , Fault isolation time T 1bnj , instruction generation time T 2nj , instruction sending and execution time T 3nj and status confirmation time T 4nj ; Sub-step 42, constructing a maintainability prediction model; wherein the maintainability prediction model includes: average on-orbit reconstruction time T OR The estimated model and average on-orbit autonomous recovery time T ORF The prediction model; Sub-step 43, taking a single device as a unit, based on the maintainability prediction model, satellite maintenance time parameter prediction is performed.

5. The parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability according to claim 4 is characterized in that: Average on-orbit reconstruction time T OR The prediction model is expressed as follows: Where N represents the number of replaceable units RI, λ n represents the failure rate of the nth RI, T n represents the average on-orbit reconstruction time of the nth RI; Where J represents the total number of faults that can be detected by the nth RI on-orbit and handled by ground remote control, λ n represents the failure rate of the jth failure mode of the nth RI, T nj represents the fault repair time of the jth fault mode of the nth RI; Among them, M nj represents the number of maintenance activities when the jth failure mode of the nth RI is repaired, T mnj It represents the average time to perform the mth maintenance activity for the jth failure mode of the nth RI; Average on-orbit function autonomous recovery time T ORF The prediction model is expressed as follows: Among them, T n ′ represents the average on-orbit autonomous functional recovery time of the nth RI; Where J′ represents the total number of faults that can be detected and autonomously recovered on-orbit by the nth RI.

6. The parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability according to claim 5 is characterized in that: Taking a single device as a unit, based on the maintainability prediction model, satellite maintenance time parameters are predicted, including: Based on the fault list determined in step 1, for each fault mode, according to the specific maintenance plan of each fault mode, estimate each repair time element specified in step 4.1 item by item to obtain the equipment data collection table; According to the equipment data collection table, data is summarized to obtain a summary data table; According to the summary data in the summary data, select the corresponding maintainability prediction model given in step 4.2 and solve to obtain the satellite maintenance time parameter prediction results.

7. The parameter evaluation method for characterizing the comprehensive capability of satellite reliability, maintainability and supportability according to claim 6 is characterized in that: The satellite availability is calculated, including: Based on the predicted results of the equipment-level failure rate and the probability of functional interruption caused by the space environment in step 3 and the predicted results of the satellite maintenance time parameters in step 4, complete the fault list of the relevant equipment listed in step 1, and use the satellite availability model to calculate and obtain the satellite availability.

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