A symbolic approach to the design of robust cyber-physical systems

Robustness plays a major role in the analysis and design of engineering systems. Although robustness is reasonably well understood in control theory, the fundamental tenets of robustness in Cyber-Physical Systems (CPSs) remain to be discovered. In this paper we present a design methodology, based on symbolic models, for robust CPSs. We combine existing notions of robustness, based on input-output stability for physical systems, with a recently developed analogue for cyber systems. Our main result states that robustness for CPS can be achieved through a decomposition of concerns: the combination of robustness of the physical system with respect to continuous disturbances and the robustness of the cyber system with respect to discrete disturbances results in a robust CPS.