A reliability analysis method for reconfigurable systems

Abstract

The present invention discloses a reliability analysis method for reconfigurable systems, comprising the following steps: 1) using a system theory method to analyze system functions and configurations, and obtain fault requirements; 2) using AADL / Simulink tools to establish a software model for the reconstruction method and reconstruction requirements; 3) using the Markov method to analyze the reliability of the reconfigurable system; 4) using a model simulation verification method and a target machine test method to measure reliability. The present invention belongs to the field of information processing technology, and in view of the shortcomings of existing reconfigurable systems, provides a reliability analysis method for reconfigurable systems, which takes the reconfigurable requirements of the system as input, uses a model to perform functional modeling and fault mode modeling on the reconfigurable requirements, performs reliability analysis of the reconfigurable system based on the Markov process, and realizes more accurate reliability estimation and analysis of the reconfigurable system.

Description

Technical Field

[0001] The invention belongs to the technical field of information processing, and specifically refers to a reliability analysis method for a reconfigurable system. Background Art

[0002] Reconfigurable systems have become one of the indispensable technologies for today's airborne equipment with their advantages of flexible functions and balanced computing performance. At the same time, the introduction of reconstruction makes the quality analysis and evaluation technology such as reliability more complicated, and has attracted much attention from relevant practitioners. Reconfiguration is a fault-tolerant mechanism. Equipment system reconstruction refers to the ability of the equipment system to change its own functions to adapt to environmental changes after the internal or external environmental conditions change. Through system reconstruction, when system components, whether hardware or software components, fail, the equipment system will switch from one resource configuration to another resource configuration, thereby ensuring system functions. However, with the increasing degree of system integration, the equipment architecture is also facing new problems. Since a single module resides in multiple applications, the failure of the module will lead to the simultaneous failure of multiple systems. Therefore, the reliability requirements of the system are more stringent, and more effective methods must be provided to ensure the reliability of the system.

[0003] In this case, in the development process of the new generation of integrated systems, such as distributed integrated modular avionics systems, the reconfiguration feature is gradually introduced. When the hardware or software of a device in the system fails, the reconfiguration mechanism allows the system to migrate functions according to the preset configuration, so that the entire system can continue to operate normally. This mechanism further improves the reliability of the avionics system. Equipment reconfiguration can be considered from three dimensions: first, the level of reconfiguration. Reconfiguration can be performed at the module level or the integrated partition level. For module-level reconfiguration, when a module fails, all applications on it are migrated to a backup module. For integrated partition-level reconfiguration, when a module fails, the applications on it are migrated to different partitions of the fault-free module; second, the location of reconfiguration. Reconfiguration can be performed between modules of the same type that have failed, or between modules of different types on the same equipment platform; third, the time of reconfiguration. Reconfiguration can occur during the execution of the mission or on the ground. Compared with fixed configuration systems, the complexity of reliability analysis of reconfigured integrated systems is significantly increased.

[0004] The introduction of reconstruction makes the reliability analysis of integrated systems more complicated. Although some reliability analysis methods have been applied to reconstructed systems, including reliability block diagrams and fault tree analysis, these analysis methods cannot accurately describe the dependencies between failure events in the reconstructed system and the specific order of failure event occurrence, and it is difficult to make accurate measurements of random failures, resulting in a relatively large error between the theoretical principles of reliability analysis of reconstructed systems and practical engineering applications. Summary of the invention

[0005] In order to solve the above-mentioned existing problems, the present invention aims at the shortcomings of existing reconfigurable systems and provides a reliability analysis method for reconfigurable systems, which takes the reconfigurable requirements of the system as input, uses a model to perform functional modeling and failure mode modeling on the reconfigurable requirements, and performs reconfigurable system reliability analysis based on the Markov process, so as to achieve more accurate reliability estimation and analysis of the reconfigurable system.

[0006] The technical solution adopted by the present invention is as follows: A reliability analysis method for a reconfigurable system comprises the following steps:

[0007] 1) Obtain fault requirements: Use system theory methods to analyze system functions and configurations to obtain fault requirements;

[0008] 2) Establish software model: Use AADL / Simulink tools to establish software model for reconstruction methods and reconstruction requirements;

[0009] 3) Reliability analysis: The reliability of the reconfigurable system is analyzed using the Markov method;

[0010] 4) Reliability measurement: Reliability measurement is achieved by using model simulation verification method and target machine testing method.

[0011] Furthermore, the step 1) of obtaining the fault requirement includes the following steps:

[0012] 1.1) Analyze the system and work task mode;

[0013] 1.2) Analyze system configuration, which includes system logical configuration and system physical configuration. The system logical configuration defines a series of processes of a given system or subsystem function, the relationship between given system or subsystem functions, and the resource requirements of the application. The system physical configuration is the implementation of the logical configuration on a real physical platform. One system logical configuration can be associated with multiple physical configurations of the system.

[0014] 1.3) Analyze the fault type and the solution to the fault;

[0015] 1.4) Obtain system reconfiguration requirements.

[0016] Furthermore, the software model established in step 2) is to use the Error Model Annex model extended by AADL to model the reliability architecture of the reconfigurable system and provide a description method of fault type, fault propagation, fault behavior and related attributes.

[0017] Furthermore, the software model established in step 2) is to use Simulink's finite state machine Stateflow model to model the reliability architecture of the reconfigurable system and provide a description method of fault type, fault propagation, fault behavior and related attributes.

[0018] Furthermore, the step 3) of analyzing the reliability of the reconfigurable system using the Markov method includes the following steps:

[0019] 3.1) Setting reliability analysis conditions: The conditions for reliability analysis of the reconfigurable system under consideration are set in advance. The reliability analysis conditions include: i) all modules of the reconfigurable system under consideration work normally when the system is initialized; ii) only one fault occurs in the reconfigurable system under consideration at a certain time; iii) all modules of the reconfigurable system under consideration are the same and have equal failure rates;

[0020] 3.2) Markov state analysis: According to the structure of the reconfigurable system under consideration, the Markov state analysis of the reconfigurable system is performed. The reconfigurable system under consideration contains three working states, among which:

[0021] State S1——system initialization and normal working state without fault;

[0022] State S2: System failure, function reconfigurable working state;

[0023] State S3: The system fails again and the work enters the failure state;

[0024] 3.3) Calculate the probability of entering each state: Give the Markov state transition probability calculation formula between each state of all states in the considered reconfigurable system, and draw the corresponding Markov state transition diagram; perform Markov analysis on this state transition, and calculate the probability of entering each state as follows:

[0025]

[0026]

[0027]

[0028] Among them, P i (t) represents the probability of state i existing at time t, λ a represents the failure rate of state S1, λ b represents the failure rate of state S2;

[0029] 3.4) Calculate and analyze the reliability of the reconfigurable system: Substitute the initial conditions: P1(t) = 1, P2(t) = 0, P3(t) = 0, solve the differential equation (1) in step 3.3, calculate and analyze the reliability of the reconfigurable system under consideration, and obtain the following results:

[0030]

[0031]

[0032]

[0033] If the system enters state S3, it means that the system fails after a reconstruction, and the reliability of the overall system is the probability that the system does not enter state S3.

[0034] By adopting the above scheme, the present invention achieves the following beneficial effects: the present invention is a reliability analysis method for reconfigurable systems, and adopts a model tool to perform software modeling on the reconfigurable requirements and configuration of the reconfigurable system, which has the advantages of being easy to understand, unified and standardized; adopts system theory to analyze the configuration and requirements of the reconfigurable system, and better describes and analyzes the causal nature of the requirements of the reconfigurable system; adopts a Markov process to analyze the reliability of the reconfigurable system, and compared with traditional reliability analysis methods such as fault trees, it can more completely describe the dynamic behavior of fault events and has a more accurate reliability estimation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0036] Figure 1 A flowchart of obtaining fault requirements of a reliability analysis method for a reconfigurable system according to the present invention;

[0037] Figure 2 A relationship diagram of a task working mode, a system logic configuration and a system physical configuration of a reliability analysis method for a reconfigurable system according to the present invention;

[0038] Figure 3 A system reconfiguration state transition diagram of a reliability analysis method for a reconfigurable system according to the present invention;

[0039] Figure 4 The present invention is a flow chart of a reliability analysis method for a reconfigurable system, which uses a Markov method to analyze the reliability of a reconfigurable system. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] A reliability analysis method for a reconfigurable system, characterized by comprising the following steps:

[0042] 1) Use the system theory method to analyze system functions and configurations and obtain fault requirements, including the following steps:

[0043] 1.1) Analyze the system and work task mode;

[0044] 1.2) Analyze system configuration, which includes system logical configuration and system physical configuration. The system logical configuration defines a series of processes of a given system or subsystem function, the relationship between given system or subsystem functions, and the resource requirements of the application. The system physical configuration is the implementation of the logical configuration on a real physical platform. One system logical configuration can be associated with multiple physical configurations of the system.

[0045] 1.3) Analyze the fault type and the solution to the fault;

[0046] 1.4) Obtain system reconfiguration requirements;

[0047] 2) Establish software model: Use AADL / Simulink tools to establish software models for the reconstruction method and reconstruction requirements. Specifically, use the EMA (Error Model Annex) model extended by AADL or the Stateflow model of Simulink to model the reliability architecture of the reconfigurable system, and provide description methods for fault types, fault propagation, fault behavior and related attributes;

[0048] 3) The reliability of the reconfigurable system is analyzed using the Markov method, which includes the following steps:

[0049] 3.1) Setting reliability analysis conditions: The conditions for reliability analysis of the reconfigurable system under consideration are set in advance. The reliability analysis conditions include: i) all modules of the reconfigurable system under consideration work normally when the system is initialized; ii) only one fault occurs in the reconfigurable system under consideration at a certain time; iii) all modules of the reconfigurable system under consideration are the same and have equal failure rates;

[0050] 3.2) Markov state analysis: According to the structure of the reconfigurable system under consideration, the Markov state analysis of the reconfigurable system is performed. The reconfigurable system under consideration contains three working states, among which:

[0051] State S1——system initialization and normal working state without fault;

[0052] State S2: System failure, function reconfigurable working state;

[0053] State S3: The system fails again and the work enters the failure state;

[0054] 3.3) Calculate the probability of entering each state: Give the Markov state transition probability calculation formula between each state of all states in the considered reconfigurable system, and draw the corresponding Markov state transition diagram; perform Markov analysis on this state transition, and the Markov state transition diagram of the considered reconfigurable system is as follows Figure 3 As shown, the probability of entering each state is calculated as follows:

[0055]

[0056]

[0057]

[0058] Among them, P i (t) represents the probability of state i existing at time t, λ a represents the failure rate of state S1, λ b represents the failure rate of state S2;

[0059] 3.4) Calculate and analyze the reliability of the reconfigurable system: Substitute the initial conditions: P1(t) = 1, P2(t) = 0, P3(t) = 0, solve the differential equation (1) in step 3.3, calculate and analyze the reliability of the reconfigurable system under consideration, and obtain the following results:

[0060]

[0061]

[0062]

[0063] If the system enters state S3, it means that the system fails after a reconstruction, and the reliability of the overall system is the probability that the system does not enter state S3;

[0064] 4) Use model simulation verification method and target machine testing method to measure reliability.

[0065] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A reliability analysis method for reconfigurable systems, characterized in that: The following steps are involved: 1) Obtain fault requirements: Use system theory methods to analyze system functions and configurations to obtain fault requirements; 2) Establish software model: Use AADL / Simulink tools to establish software model for reconstruction methods and reconstruction requirements; 3) Reliability analysis: The reliability of the reconfigurable system is analyzed using the Markov method, which includes the following steps: 3.1) Setting reliability analysis conditions: The conditions for reliability analysis of the reconfigurable system under consideration are set in advance. The reliability analysis conditions include: i) all modules of the reconfigurable system under consideration work normally when the system is initialized; ii) only one fault occurs in the reconfigurable system under consideration at a certain time; iii) all modules of the reconfigurable system under consideration are the same and have equal failure rates; 3.2) Markov state analysis: According to the structure of the reconfigurable system under consideration, the Markov state analysis of the reconfigurable system is performed. The reconfigurable system under consideration contains three working states, among which: State S1——system initialization and normal working state without fault; State S2: System failure, function reconfigurable working state; State S3: The system fails again and the work enters the failure state; 3.3) Calculate the probability of entering each state: Give the Markov state transition probability calculation formula between each state of all states in the considered reconfigurable system, and draw the corresponding Markov state transition diagram; perform Markov analysis on this state transition, and calculate the probability of entering each state as follows: Among them, P i (t) represents the probability of state i existing at time t, λ a represents the failure rate of state S1, λ b represents the failure rate of state S2; 3.4) Calculate and analyze the reliability of the reconfigurable system: Substitute the initial conditions: P1(t) = 1, P2(t) = 0, P3(t) = 0, solve the differential equation (1) in step 3.3, calculate and analyze the reliability of the reconfigurable system under consideration, and obtain the following results: If the system enters state S3, it means that the system fails after a reconstruction, and the reliability of the overall system is the probability that the system does not enter state S3; 4) Reliability measurement: Reliability measurement is achieved by using model simulation verification method and target machine testing method.

2. A reliability analysis method for reconfigurable systems according to claim 1, characterized in that: Step 1) obtaining the fault requirement includes the following steps: 1.1) Analyze the system and work task mode; 1.2) Analyze system configuration, which includes system logical configuration and system physical configuration. The system logical configuration defines a series of processes of a given system or subsystem function, the relationship between given system or subsystem functions, and the resource requirements of the application. The system physical configuration is the implementation of the logical configuration on a real physical platform. One system logical configuration can be associated with multiple physical configurations of the system. 1.3) Analyze the fault type and the solution to the fault; 1.4) Obtain system reconfiguration requirements.

3. A reliability analysis method for reconfigurable systems according to claim 1, characterized in that: The software model established in step 2) is to use the Error Model Annex model extended by AADL to model the reliability architecture of the reconfigurable system and provide a description method of fault type, fault propagation, fault behavior and related attributes.

4. A reliability analysis method for reconfigurable systems according to claim 1, characterized in that: The software model established in step 2) is to use Simulink's finite state machine Stateflow model to model the reliability architecture of the reconfigurable system and provide a description method of fault type, fault propagation, fault behavior and related attributes.

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