Robustness improvement strategy of cyber-physical systems with weak interdependency

As technologies are advancing at a rapid pace, the robustness of cyber-physical systems becomes increasingly critical. This paper presents a methodological framework for enhancing the robustness of cyber-physical systems in different failure scenarios. In particular, an AC power flow model and routing scheme are combined to model cyber-physical systems. A weak interdependency is then introduced to accurately characterize cascading failures. Different improvement strategies are finally proposed by comparing their influences on cyber-physical systems from both structural and functional perspectives. For validating the performance of the proposed framework, a case study has been conducted on several simulations. The results have shown that the key node protection strategy can alleviate the impacts of initial failures, while interdependency adjustment strategies can mitigate cascading failures. Specifically, the robustness of using the betweenness-based protection strategy has increased by 60%. The application of the performance degree based interdependency adjustment strategy has still resulted in improving robustness by 24% even if the proportion of node removals is 35%.