The objective of this research is to develop the theoretical foundations of robust cyber-physical systems. Robustness is the property ensuring that slight perturbations in the cyber, physical, or in the interaction between the cyber and the physical components, e.g., noise in sensor measurements, causes only slight changes in the system execution. While it is theoretically possible to enumerate all possible faults that can occur in a cyber-physical system and to design software components that correctly handle all such faults, the resulting specifications would be unwieldy and difficult to understand or verify. Instead, this project investigates the design of software components that guarantee robustness of cyber-physical systems with respect to unmodeled faults. The approach consist in abstracting and generalizing several key ideas from robust control theory to cyber-physical systems. The project's intellectual merit is divided in two parts. The first part consists in defining a notion of robustness for cyber-physical systems relying on finite-state abstractions of the physical world retaining metric information about physical quantities. The second part consists in developing the methods and tools for automatically synthesizing software modules enforcing desired specifications in a robust manner. The tools and techniques developed in this project will significantly enhance our ability to produce robust cyber-physical systems and thus have a broad impact in several application areas transcending computer science and control engineering. Moreover, the broader impact of the proposed research is amplified by explicitly addressing the lack of robustness in legacy software through the development of robustifying software patches. To enhance the transfer of the research results to industry, the PIs and the Electrical Engineering Office of Industrial Relations will host a workshop for the local industry on robust cyber- physical systems.