Publication

Abstract : Onboard computers use redundant hardware for fault tolerance resulting in underutilisation of resources under fault free condition. This paper exploits the resource augmented model where task allocation based on task criticality ensures safe minimal functionality under permanent fault. An algorithm has been designed for real-time scheduling with fault tolerance and precedence constraints for hot standby dual redundant navigation, guidance, and control system. This algorithm is designed for recovery under permanent hardware fault in different case studies of single, double and triple units of different types (N, G, and C). It can tolerate permanent software failures, transient hardware and software failures occurring singly or as a combination in same type unit. Tolerating increased frequency of transient and software faults with same allowable safety margins and an increased flexibility in enhanced operational performance by different operational modes under fault and fault free condition without degrading safety margins are significant performance aspects of this design. © 2017 Inderscience Enterprises Ltd.