Integrated reliability metrics to assess fault tolerant control system

This paper presents an integrated reliability definition and mathematical metrics based on function reliability and performance reliability, in which the function reliability highlights failure causality from system to components and the performance reliability focuses on the dynamic performance degradation with operational time. Based on the simulation techniques, this paper establishes the simulation template for typical control system that can describe the dynamic process of performance in continuous time until the parameters exceed the designated threshold. Considering the influence of monitoring voting system, this paper establishes the Markov model with fault detection rate, isolation rate and false alarm rate, investigates the influence to whole system reliability of such factors. Application of triple redundant actuator indicates that the integrated reliability assessment makes full use of the advantages on dynamic fault tree analysis, Markov Model and control performance simulation, and solves the difficulties on calculating reliability considering the characteristics of monitoring system and performance degradation.