Modeling Of Fault Diagnosis And Recovery Function Of Fault-tolerant System

Fault-tolerant computer systems still can complete the assigned task correctly when there is a hardware failure or software error. It uses redundancy to achieve the purpose of fault tolerance and is applied to high reliability systems.Petri net is a structured description tool of event-driven system that can adequately describe the event-driven system, the links between local and local. Fault-tolerant systems are event-driven, so Petri net can capture the sequence of fault-tolerant system events, parallel, synchronization, and other characteristics of conflict and causal dependence, and simulate the process of functional model of fault-tolerant system simply and intuitively in the form of chart, and analyze the dynamic nature of fault-tolerant system. Exspect is a simulating software to analyze the problem areas for Petri net theory and is a good tool to assist the Petri net to analysis and solve problems. ExSpect software has functions of editing graphical model, checking type and simulation. It provides an integrated working platform which can simulate the operating environment of fault-tolerant system and achieve the simulation for functional model of fault-tolerant system.In this paper, it describes the implementation mechanisms of fault diagnosis and permanent fault recovery module of triple modular redundancy fault-tolerant system. It establishes the functional models of fault diagnosis and permanent fault recovery based on Petri nets. And it uses ExSpect software to simulate the Petri net module of fault diagnosis and permanent fault recovery of triple modular redundancy fault-tolerant systems.The main contents are as follows:(1) This paper introduces the architecture of triple modular redundancy fault-tolerant system, fault-tolerant technology and the theory, advantages, and analysis method of Petri net, and proposes that using Petri net is feasible to analysis the function models of triple modular redundancy fault-tolerant system.(2) This paper theoretically explained the functional models of fault diagnosis and permanent fault recovery of triple modular redundancy fault-tolerant system based on Petri nets, and on this basis establishes and analyzes the Petri net models for fault diagnosis and permanent fault recovery of triple modular redundancy fault-tolerant system. (3) This paper simulates the functional models of fault-tolerant system with the simulation software of Exspect and analyzes the simulation results, and effectively verifies the performance of fault diagnosis model and permanent fault recovery model of triple modular redundancy fault-tolerant system based on Petri nets.