Resilience-Driven System Design of Complex Engineered Systems

TLDR

Engineered systems are traditionally designed with passive, fixed capacities or costly redundancies, making them unreliable under adverse events, while prognostics and health management (PHM) methods now enable proactive maintenance to mitigate this. The study aims to use PHM at design time to convert passive systems into resilient ones and lower life‑cycle cost. The proposed resilience‑driven system design (RDSD) framework consists of a top‑level resilience allocation problem, a bottom‑level reliability‑based design optimization, and a bottom‑level PHM design to jointly optimize resilience, reliability, and PHM efficiency. Applied to a simplified aircraft control actuator, the framework produced a highly resilient actuator with optimized reliability, PHM efficiency, and redundancy.

Abstract

Most engineered systems are designed with a passive and fixed design capacity and, therefore, may become unreliable in the presence of adverse events. Currently, most engineered systems are designed with system redundancies to ensure required system reliability under adverse events. However, a high level of system redundancy increases a system’s life-cycle cost (LCC). Recently, proactive maintenance decisions have been enabled through the development of prognostics and health management (PHM) methods that detect, diagnose, and predict the effects of adverse events. Capitalizing on PHM technology at an early design stage can transform passively reliable (or vulnerable) systems into adaptively reliable (or resilient) systems while considerably reducing their LCC. In this paper, we propose a resilience-driven system design (RDSD) framework with the goal of designing complex engineered systems with resilience characteristics. This design framework is composed of three hierarchical tasks: (i) the resilience allocation problem (RAP) as a top-level design problem to define a resilience measure as a function of reliability and PHM efficiency in an engineering context, (ii) the system reliability-based design optimization (RBDO) as the first bottom-level design problem for the detailed design of components, and (iii) the system PHM design as the second bottom-level design problem for the detailed design of PHM units. The proposed RDSD framework is demonstrated using a simplified aircraft control actuator design problem resulting in a highly resilient actuator with optimized reliability, PHM efficiency and redundancy for the given parameter settings.