Functional Logic Architecture And Reliability Analysis Of Task System

In the process of understanding and transforming the world,people often have to face all kinds of task systems with complex structure.It is particularly important to model and evaluate the reliability of task systems effectively.For the reliability evaluation of complex system,on the basis of the fact that a large number of system level reliability tests cannot be carried out,how to use the limited test information of each functional unit in the task system to effectively evaluate the reliability of the task system is a problem worthy of study.At present,the structure of the system reliability model includes combination model and state space,among which the combination model method mainly composed of reliability block diagram,fault tree and binary decision diagram is commonly used in the reliability analysis of static task system.After analyzing the above three modeling methods,this paper designs a task system model analysis and reliability evaluation method based on functional logic tree.Firstly,the working mechanism of the task system is studied and the typical system structure is decomposed to lay the foundation for the new model.After studying the working mechanism of task system,the concept of reliability is described according to the definition and characteristics of system model.Based on the reliability block diagram,fault tree and binary decision diagram,a system model based on functional logic tree architecture is proposed to describe the function of task system.Secondly,the functional logic tree is designed in detail from the aspects of basic definition,structure and construction method.It’s described mathematically by using structural function representation,adjacency and association matrix representation.The task system model is described qualitatively by minimum cut sets,and it’s analyzed quantitatively by using a variety of characteristic quantities,which lays a foundation for the combined reliability analysis of task system.Thirdly,for the real system,the problem description of the multi state task system is introduced,and the multi state function logic tree model is designed.By studying the models of series subsystem,parallel subsystem and k/n subsystem respectively according to the categories,the paper designs the transformation from the logical relationship described by functional logic tree to the mapping expression of Bayesian network nodes under different connection modes,and establishes the reliability model of multi state task system based on functional logic architecture.Finally,taking the ship return mission system as an example,the functional logic tree of this mission is realized,and the system is qualitatively analyzed by using the minimum cut set.Then,the automatic generation method of the functional logic tree of the mission system is designed.The depth first traversal algorithm of the functional logic tree is used to determine the typical modules of each module unit from data input,preset tree structure,location determination of module units to qualitative and quantitative analysis,which provides method support for the computer-aided analysis of the functional logic tree of the system.