Reliability Evaluation of Fault Tolerant Control with a Semi-Markov Fault Detection and Isolation Model

Abstract

In this paper, a stochastic modelling method is used to study the reliability evaluation problem of fault-tolerant control systems (FTCSs). The faults in the system are described by a Markov chain, while the fault detection and isolation (FDI) and system operation for reliability evaluation are described by two semi-Markov chains. The semi-Markov description of FDI removes the restrictive memoryless assumption in Markov models and provides a general model for cyclic FDI schemes. Furthermore, a reliability index and evaluation method are presented for FTCSs. This index reflects the control performance and hard deadline and can be used as a quantitative reliability measure for FTCSs.