FTSC: Fault-tolerant scheduling and control co-design for distributed real-time system

Abstract

Ensuring control stability is essential for safety-critical systems. Task redundancy is one commonly employed technique to enhance control performance in applications afflicted by intermittent faults. While increasing the number of replicas can improve control performance, it also introduces challenges in terms of scheduling and mapping. Prior research primarily focuses on controller design to enhance control performance, with limited consideration given to fault tolerance and scheduling in a combined manner. In this paper, we propose a co-design scheme of Fault-Tolerant Scheduling and Control (FTSC), which aims to provide stable control performance along with feasible mapping and scheduling solutions. We present a comprehensive formulation that encompasses mapping, scheduling, and fault tolerance, optimizing control performance into a Mixed Integer Linear Programming (MILP) framework. The problem of task redundancy can either be addressed through a heuristic algorithm efficiently or be solved in a MILP-based approach with a better solution. A case study is conducted to demonstrate the effectiveness of our proposed scheme, highlighting its ability to reduce system control costs while meeting real-time, reliability, and schedulability constraints.