Wireless sensor-actuator networks (WSAN) are systems consisting of numerous sensing and actuation devices that interact with the environment and coordinate their activities over a wireless communication network. This project studies "resilience" in WSANs. A resilient system is one that maintains an active awareness of surrounding threats and reacts to those threats in a manner that returns the system to operational normalcy in finite time. This project's approach to resilient WSANs rests on two fundamental trends. One trend uses machine-to-machine (M2M) communication networks that promise wireless networking with greater peak bit-rates and reliability than previously possible. The other trend comes from recent ideas that use quantization and event-triggered feedback in a unified manner to reduce bit rates required by real-time control systems. This project will evaluate and demonstrate this integrated control/communication approach to resilience on a multi-robotic testbed consisting of unmanned ground vehicles. The testbed will integrate M2M communication hardware/software with a multi-robot control architecture addressing task coordination and platform stabilization. This project broadens its impact through organizations and programs on and around the Notre Dame campus that facilitate industrial engagement and technology transfer. The project will engage undergraduate and graduate students to support the project's testbed and algorithm development. The project will augment and re-organize Notre Dame's Cyber-Physical System (CPS) curriculum by integrating the results of this project into courses.

This CPS Frontiers project addresses highly dynamic Cyber-Physical Systems (CPSs), understood as systems where a computing delay of a few milliseconds or an incorrectly computed response to a disturbance can lead to catastrophic consequences. Such is the case of cars losing traction when cornering at high speed, unmanned air vehicles performing critical maneuvers such as landing, or disaster and rescue response bipedal robots rushing through the rubble to collect information or save human lives. The preceding examples currently share a common element: the design of their control software is made possible by extensive experience, laborious testing and fine tuning of parameters, and yet, the resulting closed-loop system has no formal guarantees of meeting specifications. The vision of the project is to provide a methodology that allows for complex and dynamic CPSs to meet real-world requirements in an efficient and robust way through the formal synthesis of control software. The research is developing a formal framework for correct-by-construction control software synthesis for highly dynamic CPSs with broad applications to automotive safety systems, prostheses, exoskeletons, aerospace systems, manufacturing, and legged robotics. The design methodology developed here will improve the competitiveness of segments of industry that require a tight integration between hardware and highly advanced control software such as: automotive (dynamic stability and control), aerospace (UAVs), medical (prosthetics, orthotics, and exoskeleton design) and robotics (legged locomotion). To enhance the impact of these efforts, the PIs are developing interdisciplinary teaching materials to be made freely available and disseminating their work to a broad audience.

This NSF Cyber-Physical Systems (CPS) Frontiers project "Foundations Of Resilient CybEr-physical Systems (FORCES)" focuses on the resilient design of large-scale networked CPS systems that directly interface with humans. FORCES aims to pr ovide comprehensive tools that allow the CPS designers and operators to combine resilient control (RC) algorithms with economic incentive (EI) schemes. Scientific Contributions The project is developing RC tools to withstand a wide-range of attacks and faults; learning and control algorithms which integrate human actions with spatio-temporal and hybrid dynamics of networked CPS systems; and model-based design to assure semantically consistent representations across all branches of the project. Operations of networked CPS systems naturally depend on the systemic social institutions and the individual deployment choices of the humans who use and operate them. The presence of incomplete and asymmetric information among these actors leads to a gap between the individually and socially optimal equilibrium resiliency levels. The project is developing EI schemes to reduce this gap. The core contributions of the FORCES team, which includes experts in control systems, game theory, and mechanism design, are the foundations for the co-design of RC and EI schemes and technological tools for implementing them. Expected Impacts Resilient CPS infrastructure is a critical National Asset. FORCES is contributing to the development of new Science of CPS by being the first project that integrates networked control with game theoretic tools and the economic incentives of human decision makers for resilient CPS design and operation. The FORCES integrated co-design philosophy is being validated on two CPS domains: electric power distribution and consumption, and transportation networks. These design prototypes are being tested in real world scenarios. The team's research efforts are being complemented by educational offerings on resilient CPS targeted to a large and diverse audience.

This NSF Cyber-Physical Systems (CPS) Frontiers project "Foundations Of Resilient CybEr-physical Systems (FORCES)" focuses on the resilient design of large-scale networked CPS systems that directly interface with humans. FORCES aims to pr ovide comprehensive tools that allow the CPS designers and operators to combine resilient control (RC) algorithms with economic incentive (EI) schemes. Scientific Contributions The project is developing RC tools to withstand a wide-range of attacks and faults; learning and control algorithms which integrate human actions with spatio-temporal and hybrid dynamics of networked CPS systems; and model-based design to assure semantically consistent representations across all branches of the project. Operations of networked CPS systems naturally depend on the systemic social institutions and the individual deployment choices of the humans who use and operate them. The presence of incomplete and asymmetric information among these actors leads to a gap between the individually and socially optimal equilibrium resiliency levels. The project is developing EI schemes to reduce this gap. The core contributions of the FORCES team, which includes experts in control systems, game theory, and mechanism design, are the foundations for the co-design of RC and EI schemes and technological tools for implementing them. Expected Impacts Resilient CPS infrastructure is a critical National Asset. FORCES is contributing to the development of new Science of CPS by being the first project that integrates networked control with game theoretic tools and the economic incentives of human decision makers for resilient CPS design and operation. The FORCES integrated co-design philosophy is being validated on two CPS domains: electric power distribution and consumption, and transportation networks. These design prototypes are being tested in real world scenarios. The team's research efforts are being complemented by educational offerings on resilient CPS targeted to a large and diverse audience.